WorldWideScience

Sample records for eastern gulf coastal

  1. Holocene development of the eastern Gulf of Finland coastal zone (Baltic Sea)

    Science.gov (United States)

    Ryabchuk, Daria; Sergeev, Alexander; Gusentsova, Tatiana; Gerasimov, Dmitry; Zhamoida, Vladimir; Amantov, Aleksey; Kulkova, Marianna; Sorokin, Peter

    2014-05-01

    In 2011-2013 geoarcheological and marine geological research of the eastern Gulf of Finland coasts and near-shore bottom were undertaken. Researches were concentrated within several key-areas (Sestroretskaya Lowland, Narva-Luga Klint Bay and southern coastal zone of the Gulf (near Bolshaya Izhora village). Study areas can provide important information about Gulf of Finland Holocene coastal development as since Ancylus time (about 10000 cal.BP). Development of numerous sand accretion forms (spits, bars, dunes) of different shape, age and genesis caused formation of lagoon systems, situated now on-land due to land uplift. Coasts of lagoons in Sestroretskaya Lowland and Narva-Luga Klint Bay were inhabited by Neolithic and Early Metal people. Analysis of coastal morphology and results of geological research (GIS relief analyses, ground penetrating radar, drilling, grain-size analyses, radiocarbon dating) and geoarcheological studies allowed to reconstruct the mechanism of large accretion bodies (bars and spits) and lagoon systems formation during last 8000 years. Geoarcheological studies carried out within eastern Gulf of Finland coasts permitted to find some features of the Neolithic - Early Metal settlements distribution. Another important features of the eastern Gulf of Finland coastal zone relief are the series of submarine terraces found in the Gulf bottom (sea water depths 10 to 2 m). Analyses of the submarine terraces morphology and geology (e.g. grain-size distribution, pollen analyses and organic matter dating) allow to suppose that several times during Holocene (including preAncylus (11000 cal.BP) and preLittorina (8500 cal.BP) regressions) the sea-water level was lower than nowadays. During the maximal stage of the Littorina transgression (7600-7200 cal. BP) several open bays connected with the Littorina Sea appeared in this area. The lagoon systems and sand accretion bodies (spits and bars) were formed during the following decreasing of the sea level. Late

  2. Mesozoic (Upper Jurassic-Lower Cretaceous) deep gas reservoir play, central and eastern Gulf coastal plain

    Science.gov (United States)

    Mancini, E.A.; Li, P.; Goddard, D.A.; Ramirez, V.O.; Talukdar, S.C.

    2008-01-01

    The Mesozoic (Upper Jurassic-Lower Cretaceous) deeply buried gas reservoir play in the central and eastern Gulf coastal plain of the United States has high potential for significant gas resources. Sequence-stratigraphic study, petroleum system analysis, and resource assessment were used to characterize this developing play and to identify areas in the North Louisiana and Mississippi Interior salt basins with potential for deeply buried gas reservoirs. These reservoir facies accumulated in Upper Jurassic to Lower Cretaceous Norphlet, Haynesville, Cotton Valley, and Hosston continental, coastal, and marine siliciclastic environments and Smackover and Sligo nearshore marine shelf, ramp, and reef carbonate environments. These Mesozoic strata are associated with transgressive and regressive systems tracts. In the North Louisiana salt basin, the estimate of secondary, nonassociated thermogenic gas generated from thermal cracking of oil to gas in the Upper Jurassic Smackover source rocks from depths below 3658 m (12,000 ft) is 4800 tcf of gas as determined using software applications. Assuming a gas expulsion, migration, and trapping efficiency of 2-3%, 96-144 tcf of gas is potentially available in this basin. With some 29 tcf of gas being produced from the North Louisiana salt basin, 67-115 tcf of in-place gas remains. Assuming a gas recovery factor of 65%, 44-75 tcf of gas is potentially recoverable. The expelled thermogenic gas migrated laterally and vertically from the southern part of this basin to the updip northern part into shallower reservoirs to depths of up to 610 m (2000 ft). Copyright ?? 2008. The American Association of Petroleum Geologists. All rights reserved.

  3. Parasite survey of the eastern oyster Crassostrea virginica in coastal lagoons of the southern Gulf of Mexico.

    Science.gov (United States)

    Aguirre-Macedo, Ma Leopoldina; Simá-Alvarez, Raúl A; Román-Magaña, María Karla; Güemez-Ricalde, Jorge I

    2007-12-01

    A parasitological study of the eastern oyster Crassostrea virginica from 11 coastal lagoons in the southern Gulf of Mexico in dry and rainy seasons between late 1999 and early 2001 revealed the presence of 36 bacterial, 2 protozoan (Nematopsis prytherchi and Perkinsus marinus), and 4 helminth species (Urastoma cyprinae, Proctoeces maculatus, a Bucephalus sp., and a Tylocephalum sp.). The prevalence and mean abundances for the protozoa and helminths varied widely between locations but were generally below 50%. Nematopsis prytherchi and the Tylocephalum sp. were the most prevalent species (values were above 60% in most locations). Perkinsus marinus was present in oysters of eight of the coastal lagoons and had low prevalence (Mexico and are common oyster parasites. Only P. marinus and the Bucephalus sp. were associated with damage to host tissues. In addition to these parasites, Rickettsia-like bacteria were found in the digestive gland and gills and viral gametocytic hypertrophy inclusions in the gonads by histological examination.

  4. An integrated approach to the assessment of the eastern Gulf of Finland health: A case study of coastal habitats

    Science.gov (United States)

    Berezina, Nadezhda A.; Gubelit, Yulia I.; Polyak, Yulia M.; Sharov, Andrey N.; Kudryavtseva, Valentina A.; Lubimtsev, Vasily A.; Petukhov, Vasily A.; Shigaeva, Tatyana D.

    2017-07-01

    Eutrophication and chemical pollution are typical threats to the ecosystem of the Gulf of Finland. This paper aims to make a comprehensive assessment of the environmental status of coastal habitats in the easternmost Gulf of Finland (Neva River estuary) by using different physical, chemical and biotic variables to find cost-effective indicators for further monitoring. During summers of 2014 and 2015 we measured water salinity, phosphorus (eutrophication marker), biomass of harmful filamentous macroalgae (coastline hypoxia inductor), sediment hazardous substances (trace metals, polycyclic aromatic hydrocarbons) and other concomitant characters at 12 sites in the gulf. Also, we analyzed responses of the phytoplankton and benthic organisms, including metal-tolerant and hydrocarbon-oxidizing bacteria, meio- and macrofauna, to these factors. We compared the indicative sensitivity and efficiency of several well-known biotic indices and methods, including a Saprobity system (basing on phytoplankton), Raffaelli and Mason index (meiobenthos), and two macrobenthic derived indices (Goodnight-Whitley Index and Benthic Quality Index). Also, we applied a new index - the embryo malformation frequency in benthic amphipods. To estimate the level of bottom hypoxia induced by the macroalgae blooms, we measured the algal cover and thickness of the algal mats. To verify our assessment, we tested correlations between all used variables. Biotic communities of these areas are subjected to high phosphorus and macroalgae blooms, toxic pollution, water salinity and other factors. We concluded that environmental state of coastal habitats at several southern sites (in Koporskaya Bay and near the developing port Bronka) and near port Primorsk in the north was bad, while the state of the rest of sites was moderate or good. The integrated approach for the assessment may be recommended for monitoring programs as an important tool for studying human-mediated and other effects on brackishwater

  5. Spring phytoplankton in the eastern coastal Gulf of Alaska: Photosynthesis and production during high and low bloom years

    Science.gov (United States)

    Strom, Suzanne L.; Fredrickson, Kerri A.; Bright, Kelley J.

    2016-10-01

    Primary production associated with the spring bloom in high-latitude seas constitutes a substantial fraction of annual total in those environments, and provides a seasonally timed bounty to benthic and pelagic organisms at higher trophic levels. Light is widely believed to regulate the timing and magnitude of spring production in the coastal Gulf of Alaska, although few data are available on the relationship between light and photosynthesis or primary production in that region. In two cruises to the coastal waters of southeast Alaska (May 2011 and April 2013), we observed strongly contrasting early-season phytoplankton communities, although environmental conditions were largely similar. An early, diatom-dominated spring bloom occurred in April 2013, while the anomalously low chlorophyll conditions of spring 2011 were widely observed in May of that year. Integrated chlorophyll a (Chl) was substantially higher in April 2013 than in May 2011 (median 62 versus 29 mg m-2), and April 2013 saw a greater contribution by large cells (>20 μm size fraction) to total Chl. The rate (0.18 versus 0.65 d-1), and a greater biomass of picophytoplankton (cells ≤2 μm) in 2011. Photosynthesis-irradiance experiments in both years revealed low light-acclimated spring communities, with high photosynthetic efficiencies (αB) and low irradiances for the onset of light saturation, contrasting strongly with the high light-acclimated summer Gulf of Alaska community previously described. Photoinhibition was seen in both springs but was more frequent and severe in the small cell-dominated community of 2011. Maximum photosynthetic rates (PMB) were higher in the high-Chl month of April 2013 than in May 2011, averaging 5.3 versus 3.4 μg C μg Chl-1 h-1 across all depths and both size classes. In May 2011, PMB showed a strong negative correlation with salinity, while several photosynthetic parameters were correlated to light exposure history. In contrast, we found no environmental correlates to

  6. Seawater intrusion mapping using electrical resistivity tomography and hydrochemical data. An application in the coastal area of eastern Thermaikos Gulf, Greece

    Energy Technology Data Exchange (ETDEWEB)

    Kazakis, N., E-mail: kazanera@yahoo.com [Aristotle University of Thessaloniki, Department of Geology, Lab. of Engineering Geology & Hydrogeology, 54124 Thessaloniki (Greece); Pavlou, A. [Aristotle University of Thessaloniki, Department of Geology, Lab. of Engineering Geology & Hydrogeology, 54124 Thessaloniki (Greece); Vargemezis, G. [Aristotle University of Thessaloniki, Department of Geology, Lab. of Applied Geophysics, 54124 Thessaloniki (Greece); Voudouris, K.S.; Soulios, G. [Aristotle University of Thessaloniki, Department of Geology, Lab. of Engineering Geology & Hydrogeology, 54124 Thessaloniki (Greece); Pliakas, F. [Democritus University of Thrace, Department of Civil Engineering, Xanthi 67100 (Greece); Tsokas, G. [Aristotle University of Thessaloniki, Department of Geology, Lab. of Applied Geophysics, 54124 Thessaloniki (Greece)

    2016-02-01

    The aim of this study was to determine the extent and geometrical characteristics of seawater intrusion in the coastal aquifer of the eastern Thermaikos Gulf, Greece. Hydrochemical data and geoelectrical measurements were combined and supplemented to determine the hydrochemical regime of the study site in regard to seawater phenomena. Chemical analysis of groundwater was performed in 126 boreholes and fifteen electrical resistivity tomographies (ERT) were measured, whereas in two sites the ERT measurements were repeated following the wet season. The Cl{sup −} concentrations recorded reached 2240 mg/L indicating seawater intrusion which was also verified by ionic ratios. The ionic ratios were overlapped and a seawater intrusion map (SWIM) was produced. A significant part of the coastal aquifer (up to 150 km{sup 2}) is influenced by seawater intrusion. The areas with the most intensive salinization are located between Nea Kallikratia–Epanomi and Aggelochori–Peraia. According to the ERTs, in the influenced areas the salinization of the aquifer exceeds 1 km toward the mainland and its depth reaches 200 m. In the area surrounding Thessaloniki airport, the ERTs revealed salinization of the upper aquifer to depths of up to 40 m, whereas the lower aquifer is uninfluenced. This abnormal distribution of seawater intrusion demonstrates the value of geoelectrical methods in the study of seawater intrusion especially in areas with limited available hydrochemical data. - Highlights: • ERTs determined the geometrical characteristics of the saline aquifer. • An abnormal distribution of seawater intrusion was recorded. • Four ionic ratios overlapped and a seawater intrusion map was produced. • Cl{sup −} concentrations increased significantly from 2005 to 2010 by up to 1800 mg/L.

  7. Global climate change impacts on coastal ecosystems in the Gulf of Mexico: considerations for integrated coastal management

    Science.gov (United States)

    Day, John W.; Yáñez-Arancibia, Alejandro; Cowan, James H.; Day, Richard H.; Twilley, Robert R.; Rybczyk, John R.

    2013-01-01

    Global climate change is important in considerations of integrated coastal management in the Gulf of Mexico. This is true for a number of reasons. Climate in the Gulf spans the range from tropical to the lower part of the temperate zone. Thus, as climate warms, the tropical temperate interface, which is currently mostly offshore in the Gulf of Mexico, will increasingly move over the coastal zone of the northern and eastern parts of the Gulf. Currently, this interface is located in South Florida and around the US-Mexico border in the Texas-Tamaulipas region. Maintaining healthy coastal ecosystems is important because they will be more resistant to climate change.

  8. The forecast of coastal recession in the eastern gulf of Finland for the twenty-first century

    Science.gov (United States)

    Leont'yev, I. O.; Ryabchuk, D. V.; Sergeev, A. Yu.; Kovaleva, O. A.

    2015-05-01

    The evolution of a significant part of the coast in the study area is determined by extreme storm surges eroding the upper part of dunes and inducing coastal recession. In order to forecast the recession a special method using numerical modelling of storm-induced changes in the coastal profiles based on the CROSS-P model is used. The response of the shoreline profile to sea-level rise is estimated using the Bruun rule. Three types of future coastal evolution are distinguished depending on slope of an active part of the profile. It is shown that if the most probable patterns of storm activity and sea level rise occur then the relatively steep coasts in an area from Komarovo to Solnechnoe will retreat by 302-40 meters. Recession of less steep coasts (Ushkovo, south Kotlin, and Petrodvorets) is expected to be 10-20 meters, whereas the extremely gently dipping coasts (in the vicinity of Sestroretsk and near the northern end of the St. Petersburg Flood Protection Complex (FPC)) will retreat by 50-100 m.

  9. Improved Oil Recovery from Upper Jurassic Smackover Carbonates through the Application of Advanced Technologies at Womack Hill Oil Field, Choctaw and Clarke Counties, Eastern Gulf Coastal Plain

    Energy Technology Data Exchange (ETDEWEB)

    Ernest A. Mancini

    2003-12-31

    Pruet Production Co. and the Center for Sedimentary Basin Studies at the University of Alabama, in cooperation with Texas A&M University, Mississippi State University, University of Mississippi, and Wayne Stafford and Associates proposed a three-phase, focused, comprehensive, integrated and multidisciplinary study of Upper Jurassic Smackover carbonates (Class II Reservoir), involving reservoir characterization and 3-D modeling (Phase I) and a field demonstration project (Phases II and III) at Womack Hill Field Unit, Choctaw and Clarke Counties, Alabama, eastern Gulf Coastal Plain. Phase I of the project has been completed. The principal objectives of the project are: increasing the productivity and profitability of the Womack Hill Field Unit, thereby extending the economic life of this Class II Reservoir and transferring effectively and in a timely manner the knowledge gained and technology developed from this project to producers who are operating other domestic fields with Class II Reservoirs. The major tasks of the project included reservoir characterization, recovery technology analysis, recovery technology evaluation, and the decision to implement a demonstration project. Reservoir characterization consisted of geoscientific reservoir characterization, petrophysical and engineering property characterization, microbial characterization, and integration of the characterization data. Recovery technology analysis included 3-D geologic modeling, reservoir simulation, and microbial core experiments. Recovery technology evaluation consisted of acquiring and evaluating new high quality 2-D seismic data, evaluating the existing pressure maintenance project in the Womack Hill Field Unit, and evaluating the concept of an immobilized enzyme technology project for the Womack Hill Field Unit. The decision to implement a demonstration project essentially resulted in the decision on whether to conduct an infill drilling project in Womack Hill Field. Reservoir performance

  10. A Driver Pressure State Impact Response (DPSIR) framework applied to an interdisciplinary coastal zone management workshop along the eastern Gulf of Thailand.

    Science.gov (United States)

    Hines, E.; Baldwin, C.; Jones, C.; Lewison, R. L.; Lieske, S.; Rudd, M.

    2016-02-01

    The flexibility of the Driver Pressure State Impact Response (DPSIR) framework is demonstrated through application to the coastal zone of east Gulf of Thailand during an inter-disciplinary multi-cultural workshop comprised of participants (including practitioners) from south-east Asian coastal countries, North America and Australia in January 2015. The benefits of the framework as identified by participants included systematic and critical thinking, and identification of data gaps and other needs, such as capacity building. We use four case studies that highlight cross-border social-ecological challenges in Thailand and Cambodia to demonstrate: a) participant learning, b) individuality and flexibility of approaches (e.g. scales considered), c) participants' feedback on its application, and d) its potential use to identify both data-gaps and low-hanging-fruit type actions.

  11. Ways of Fishery Local Life: Processes of Participation in Management of Natural Resources in the Coastal Areas of the Upper Gulf of Eastern Area

    Directory of Open Access Journals (Sweden)

    Sulak Sa-Ngiamlak

    2011-01-01

    Full Text Available Problem statement: Local fishery was an inherited occupation for a long time. The objective of this research were to study: (1 the local fishery lifestyle of community in local fishery on upper area in Gulf of Thailand, (2 the appropriate participation process in natural resource management on upper part in Gulf of Thailand of people and organization and (3 the guidelines in natural resource management on the coastal area in upper part on Gulf of Thailand as relevant to local fishery lifestyle. Approach: The research area consisted of the shore of upper area in Gulf of Thailand including: Chachoengsao, Samutprakan, Samutsakon, Samutsongkram, Pechburi, Chonburi, Ra-yong, Chantaburi and Trad provinces. The samples as informants were 100 persons. The instruments using for data collection included the Survey, Interview Form, Observation Form, Record Form of Focus Group Discussion and Record Form of Participatory Workshop. The obtained data were classified into groups and investigated by using Triangulation Technique. Qualitative data were analyzed based on specified objectives. Results: The study of local fishery lifestyle found that there was location as in the present area owing to the fertility of area next to the sea. So, they could earn their living by fishery on coastal area. The local fishermen’s lifestyle was simple. Their living places were wooden houses with high space under a Thai house. For relationship of relative groups, they still helped each other among community people. They had belief in guardian spirit of a ship or boat and Kromluang Choomponke dudomsak. They did traditional fishery. Most of their instruments were made by themselves and adapted based on appropriateness. The wisdoms were transferred within their family, (2 the participation process in appropriate natural resource management, found that based on problem situations of natural resource on coastal area in upper area on Gulf of Thailand, being destroyed. Consequently

  12. Improved Oil Recovery from Upper Jurassic Smackover Carbonates through the Application of Advanced Technologies at Womack Hill Oil Field, Choctaw and Clarke Counties, Eastern Gulf Coastal Plain

    Energy Technology Data Exchange (ETDEWEB)

    Ernest A. Mancini

    2003-12-31

    Pruet Production Co. and the Center for Sedimentary Basin Studies at the University of Alabama, in cooperation with Texas A&M University, Mississippi State University, University of Mississippi, and Wayne Stafford and Associates proposed a three-phase, focused, comprehensive, integrated and multidisciplinary study of Upper Jurassic Smackover carbonates (Class II Reservoir), involving reservoir characterization and 3-D modeling (Phase I) and a field demonstration project (Phases II and III) at Womack Hill Field Unit, Choctaw and Clarke Counties, Alabama, eastern Gulf Coastal Plain. Phase I of the project has been completed. The principal objectives of the project are: increasing the productivity and profitability of the Womack Hill Field Unit, thereby extending the economic life of this Class II Reservoir and transferring effectively and in a timely manner the knowledge gained and technology developed from this project to producers who are operating other domestic fields with Class II Reservoirs. The major tasks of the project included reservoir characterization, recovery technology analysis, recovery technology evaluation, and the decision to implement a demonstration project. Reservoir characterization consisted of geoscientific reservoir characterization, petrophysical and engineering property characterization, microbial characterization, and integration of the characterization data. Recovery technology analysis included 3-D geologic modeling, reservoir simulation, and microbial core experiments. Recovery technology evaluation consisted of acquiring and evaluating new high quality 2-D seismic data, evaluating the existing pressure maintenance project in the Womack Hill Field Unit, and evaluating the concept of an immobilized enzyme technology project for the Womack Hill Field Unit. The decision to implement a demonstration project essentially resulted in the decision on whether to conduct an infill drilling project in Womack Hill Field. Reservoir performance

  13. Coastal fisheries in the Eastern Baltic Sea (Gulf of Finland and its basin from the 15 to the Early 20th centuries.

    Directory of Open Access Journals (Sweden)

    Julia Lajus

    Full Text Available The paper describes and analyzes original data, extracted from historical documents and scientific surveys, related to Russian fisheries in the southeastern part of the Gulf of Finland and its inflowing rivers during the 15- early 20(th centuries. The data allow tracing key trends in fisheries development and in the abundance of major commercial species. In particular, results showed that, over time, the main fishing areas moved from the middle part of rivers downstream towards and onto the coastal sea. Changes in fishing patterns were closely interrelated with changes in the abundance of exploited fish. Anadromous species, such as Atlantic sturgeon, Atlantic salmon, brown trout, whitefish, vimba bream, smelt, lamprey, and catadromous eel were the most important commercial fish in the area because they were abundant, had high commercial value and were easily available for fishing in rivers. Due to intensive exploitation and other human-induced factors, populations of most of these species had declined notably by the early 20(th century and have now lost commercial significance. The last sturgeon was caught in 1996, and today only smelt and lamprey support small commercial fisheries. According to historical sources, catches of freshwater species such as roach, ide, pike, perch, ruffe and burbot regularly occurred, in some areas exceeding half of the total catch, but they were not as important as migrating fish and no clear trends in abundance are apparent. Of documented marine catch, Baltic herring appeared in the 16(th century, but did not become commercially significant until the 19(th century. From then until now herring have been the dominant catch.

  14. Coastal fisheries in the Eastern Baltic Sea (Gulf of Finland) and its basin from the 15 to the Early 20th centuries.

    Science.gov (United States)

    Lajus, Julia; Kraikovski, Alexei; Lajus, Dmitry

    2013-01-01

    The paper describes and analyzes original data, extracted from historical documents and scientific surveys, related to Russian fisheries in the southeastern part of the Gulf of Finland and its inflowing rivers during the 15- early 20(th) centuries. The data allow tracing key trends in fisheries development and in the abundance of major commercial species. In particular, results showed that, over time, the main fishing areas moved from the middle part of rivers downstream towards and onto the coastal sea. Changes in fishing patterns were closely interrelated with changes in the abundance of exploited fish. Anadromous species, such as Atlantic sturgeon, Atlantic salmon, brown trout, whitefish, vimba bream, smelt, lamprey, and catadromous eel were the most important commercial fish in the area because they were abundant, had high commercial value and were easily available for fishing in rivers. Due to intensive exploitation and other human-induced factors, populations of most of these species had declined notably by the early 20(th) century and have now lost commercial significance. The last sturgeon was caught in 1996, and today only smelt and lamprey support small commercial fisheries. According to historical sources, catches of freshwater species such as roach, ide, pike, perch, ruffe and burbot regularly occurred, in some areas exceeding half of the total catch, but they were not as important as migrating fish and no clear trends in abundance are apparent. Of documented marine catch, Baltic herring appeared in the 16(th) century, but did not become commercially significant until the 19(th) century. From then until now herring have been the dominant catch.

  15. 78 FR 42021 - Atlantic Highly Migratory Species; Commercial Gulf of Mexico Aggregated Large Coastal Shark and...

    Science.gov (United States)

    2013-07-15

    ... Species; Commercial Gulf of Mexico Aggregated Large Coastal Shark and Gulf of Mexico Hammerhead Shark... management groups for aggregated large coastal sharks (LCS) and hammerhead sharks in the Gulf of Mexico...: The commercial Gulf of Mexico aggregated LCS and Gulf of Mexico hammerhead shark management groups...

  16. EAARL Coastal Topography - Northern Gulf of Mexico

    Science.gov (United States)

    Nayegandhi, Amar; Brock, John C.; Sallenger, Abby; Wright, C. Wayne; Travers, Laurinda J.; Lebonitte, James

    2008-01-01

    These remotely sensed, geographically referenced elevation measurements of Lidar-derived coastal topography were produced as a collaborative effort between the U.S. Geological Survey (USGS), Florida Integrated Science Center (FISC), St. Petersburg, FL and the National Aeronautics and Space Administration (NASA), Wallops Flight Facility, VA. One objective of this research is to create techniques to survey areas for the purposes of geomorphic change studies following major storm events. The USGS Coastal and Marine Geology Program's National Assessment of Coastal Change Hazards project is a multi-year undertaking to identify and quantify the vulnerability of U.S. shorelines to coastal change hazards such as effects of severe storms, sea-level rise, and shoreline erosion and retreat. Airborne Lidar surveys conducted during periods of calm weather are compared to surveys collected following extreme storms in order to quantify the resulting coastal change. Other applications of high-resolution topography include habitat mapping, ecological monitoring, volumetric change detection, and event assessment. The purpose of this project is to provide highly detailed and accurate datasets of the northern Gulf of Mexico coastal areas, acquired on September 19, 2004, immediately following Hurricane Ivan. The datasets are made available for use as a management tool to research scientists and natural resource managers. An innovative airborne Lidar instrument originally developed at the NASA Wallops Flight Facility, and known as the Experimental Airborne Advanced Research Lidar (EAARL), was used during data acquisition. The EAARL system is a raster-scanning, waveform-resolving, green-wavelength (532 nanometer) Lidar designed to map near-shore bathymetry, topography, and vegetation structure simultaneously. The EAARL sensor suite includes the raster-scanning, water-penetrating full-waveform adaptive Lidar, a down-looking RGB (red-green-blue) digital camera, a high-resolution multi

  17. Gulf of California biogeographic regions based on coastal zone color scanner imagery

    Science.gov (United States)

    SantamaríA-Del-Angel, Eduardo; Alvarez-Borrego, Saúl; Müller-Karger, Frank E.

    1994-04-01

    Topographically, the Gulf of California is divided into a series of basins and trenches that deepen to the south. Maximum depth at the mouth is greater than 3000 m. Most of the northern gulf is less than 200 m deep. The gulf has hydrographic features conducive to high primary productivity. Upwelling events have been described on the basis of temperature distributions at the eastern coast during winter and spring and at the western coast during summer. Tidal amplitude may be as high as 9 m in the upper gulf. On the basis of discrete phytoplankton sampling, the gulf was previously divided into four geographic regions. This division took into consideration only the space distribution, taxonomic composition, and abundance of microphytoplankton. With the availability of the coastal zone color scanner (CZCS) imagery, we were able to include the time variability of pigments to make a more detailed biogeographic division of the gulf. With weekly composites of the imagery, we generated time series of pigment concentrations for 33 locations throughout the gulf and for the whole life span of the CZCS. The time series show a clear seasonal variation, with maxima in winter and spring and minima in summer. The effect of upwelling at the eastern coast is clearly evident, with high pigment concentrations. The effect of the summer upwelling off the Baja California coast is not evident in these time series. Time series from locations on the western side of the gulf also show maxima in winter and spring that are due to the eddy circulation that brings upwelled water from the eastern side. Principal-component analysis was applied to define 14 regions. Ballenas Channel, between Angel de la Guarda and Baja California, and the upper gulf always appeared as very distinct regions. Some of these 14 regions relate to the geographic distributions of important faunal groups, including the benthos, or their life cycles. For example, the upper gulf is a place for reproduction and the nursery of

  18. Nutrient and metal pollution of the eastern Gulf of Finland coastline: Sediments, macroalgae, microbiota.

    Science.gov (United States)

    Gubelit, Yulia; Polyak, Yulia; Dembska, Grazyna; Pazikowska-Sapota, Grazyna; Zegarowski, Lukasz; Kochura, Dmitry; Krivorotov, Denis; Podgornaya, Elena; Burova, Olga; Maazouzi, Chafik

    2016-04-15

    The anthropogenic pollution along the coastline of the eastern Gulf of Finland was studied through a range of methods, including analyses of metal contamination in water, surface sediments, accumulated algal biomass and its correlation with resistant microbiota. According to concentrations, the main pollutants in water were copper and manganese. Influence of Nuclear Power Plant was remarkable in adjacent areas and was expressed in high concentrations of molybdenum, nickel, copper and other elements in the water. Relatively high concentrations of copper, lead and zinc were found in sediments. Microbial tolerance appeared to be correlated with the concentration of the metals in sediments. Higher tolerance levels were found in sediment samples from more polluted stations. Macroalgae, which were massively developed in the coastal zone, had shown high level of metal bioaccumulation. Analyses of carbon, nitrogen and phosphorus content of algal tissues allowed the estimation of additional nutrient loading from accumulated decaying algal biomass on the coastal zone of the eastern Gulf of Finland. Mass development of algae in coastal area may contribute to accumulation of organic matter and associated metals. In our study the highest metal concentrations in sediments were found at the sites with dense and continuous layer of fresh and decaying macroalgal biomass, accompanied by hypoxic conditions. Also our study has shown that accumulated biomass may be a significant source of nutrients in the coastal ecosystem.

  19. Nutrient and metal pollution of the eastern Gulf of Finland coastline: Sediments, macroalgae, microbiota

    Energy Technology Data Exchange (ETDEWEB)

    Gubelit, Yulia, E-mail: Gubelit@list.ru [Zoological Institute of the Russian Academy of Sciences, St. Petersburg (Russian Federation); Polyak, Yulia [Scientific Research Center for Ecological Safety of the Russian Academy of Sciences, St. Petersburg (Russian Federation); Dembska, Grazyna; Pazikowska-Sapota, Grazyna; Zegarowski, Lukasz [Maritime Institute in Gdansk, Department of Environmental Protection, Gdansk (Poland); Kochura, Dmitry; Krivorotov, Denis; Podgornaya, Elena; Burova, Olga [Research Institute of Hygiene, Occupational Pathology and Human Ecology (RIHOPHE), Federal Medical Biological Agency, St. Petersburg (Russian Federation); Maazouzi, Chafik [Université Claude Bernard Lyon 1, Laboratoire d' Écologie des Hydrosystèmes Naturels et Anthropisés (LEHNA), Lyon (France)

    2016-04-15

    The anthropogenic pollution along the coastline of the eastern Gulf of Finland was studied through a range of methods, including analyses of metal contamination in water, surface sediments, accumulated algal biomass and its correlation with resistant microbiota. According to concentrations, the main pollutants in water were copper and manganese. Influence of Nuclear Power Plant was remarkable in adjacent areas and was expressed in high concentrations of molybdenum, nickel, copper and other elements in the water. Relatively high concentrations of copper, lead and zinc were found in sediments. Microbial tolerance appeared to be correlated with the concentration of the metals in sediments. Higher tolerance levels were found in sediment samples from more polluted stations. Macroalgae, which were massively developed in the coastal zone, had shown high level of metal bioaccumulation. Analyses of carbon, nitrogen and phosphorus content of algal tissues allowed the estimation of additional nutrient loading from accumulated decaying algal biomass on the coastal zone of the eastern Gulf of Finland. Mass development of algae in coastal area may contribute to accumulation of organic matter and associated metals. In our study the highest metal concentrations in sediments were found at the sites with dense and continuous layer of fresh and decaying macroalgal biomass, accompanied by hypoxic conditions. Also our study has shown that accumulated biomass may be a significant source of nutrients in the coastal ecosystem. - Highlights: • We studied heavy metal pollution in the coastline of the eastern Gulf of Finland. • Sediments, water, mass macroalgae and microbiota were included into analyses. • Eutrophication and nutrient loading remain the main problem of the studied area. • Macroalgae contribute to accumulation of organic matter, nutrient, and heavy metal. • Pollution in the studied area is caused by a combination of different factors.

  20. Study of Evacuation Behavior of Coastal Gulf of Mexico Residents

    OpenAIRE

    Bhattacharjee, Sanjoy; Petrolia, Daniel R.; Hanson, Terrill R.

    2009-01-01

    In this study, we investigate the link between hurricane characteristics, demographics of the Coastal Gulf of Mexico residents, including their household location, and their respective evacuation behavior. Our study is significantly different from the previously made studies on hurricane evacuation behavior in two ways. At first, the research data is collected through recording responses to a series of hypothetical situations which are quite identical to the set of information that people are...

  1. Line transect estimates of Irrawaddy dolphin abundance along the eastern Gulf Coast of Thailand.

    Directory of Open Access Journals (Sweden)

    Ellen eHines

    2015-09-01

    Full Text Available Effective conservation of coastal marine mammals is largely dependent on reliable knowledge of their abundance, as well as the ecological and human factors driving their distribution. In developing countries, lack of resources and capacity frequently impedes research needed to estimate abundance and to determine the ecological requirements of coastal marine mammals and the impact of threats related to coastal development and fisheries. Over the course of five years, we developed practical research methods and trained local scientists in Thailand to use accepted line transect distance sampling methods for abundance assessment. The study focused on a little-known coastal and freshwater species found throughout Southeast Asia, namely the Irrawaddy dolphin, which has been sighted regularly along the coast of the eastern Gulf of Thailand. During five years of line transect boat surveys in Trat Province, the eastern-most province in Thailand, we found an average of 423 dolphins distributed within 12km of the coast. Compared to other abundance estimates of coastal Irrawaddy dolphins in Southeast Asia, this is a relatively large number. This population could extend into the northern coast of Cambodia, where surveys are currently being planned. The Thai government has begun talks with Cambodia about a transboundary marine protected area that would include areas in both countries where coastal Irrawaddy dolphins are found. Other analyses include photo-identification, modeling environmental factors that determine presence, determination of fresh vs. salt water foraging using stable isotopes, and an assessment of threats. Collaboration between scientists in Thailand, Cambodia and Vietnam is further needed to determine dolphin movement and habitat use across borders.

  2. Sediment microbial activity and its relation to environmental variables along the eastern Gulf of Finland coastline

    Science.gov (United States)

    Polyak, Yulia; Shigaeva, Tatyana; Gubelit, Yulia; Bakina, Ludmila; Kudryavtseva, Valentina; Polyak, Mark

    2017-07-01

    Sediment microbial activity and its relationship with the main environmental factors and pollutants were examined in the coastal area of the eastern Gulf of Finland, Baltic Sea. The activity of two common oxidoreductase enzymes: dehydrogenase (DA) and catalase (CA) varied significantly between 13 study sites. In the Neva Bay the highest microbial activities (DA: 2.64 mg TFF (10 g- 1) day- 1, CA: 6.29 mg H2O2 g- 1) were recorded, while in the outer estuary the minimum values of dehydrogenase and catalase were measured. DA, CA, and abundances of culturable heterotrophic bacteria (CHB) were positively correlated with each other, while biomass of green opportunistic algae was independent of both microbial activities and CHB. Enzymatic activity was found to be strongly positively correlated with sediment particle size and organic matter content, but unrelated to the other studied environmental parameters (temperature, pH, and salinity). Principal components analysis (PCA), controlling for environmental variables, supported direct effects of metal and oil contamination on sediment microbial activity. Also it had shown the similar patterns for algal biomass and metals. Our results suggest that copper and hydrocarbons are the main anthropogenic variables influencing enzyme distribution along the eastern Gulf of Finland coastline.

  3. Diurnal/Inertial Oscillations on the West Florida Shelf in the Eastern Gulf of Mexico.

    Science.gov (United States)

    Maksimova, E. V.; Weisberg, R. H.

    2015-12-01

    Oscillations of diurnal/inertial frequency on the West Florida Shelf in the Eastern Gulf of Mexico are thought to be seasonally important for mixing the shelf waters because of their tendency to have large vertical shear and to be quite energetic. Such oscillations are also thought to seasonally affect the ecology of the region through daily vertical thermocline migration. The presentation will focus on some novel findings about the diurnal/inertial coastal current fluctuations based on unique observational and modeled data sets on the West Florida Shelf. The properties of the oscillations, including spatial and temporal characteristics, and mechanisms of generation and propagation will be discussed. This presentation is based upon work supported by the National Science Foundation Ocean Sciences Postdoctoral Research Fellowship under Grant OCE-1421180 (E. V. Maksimova).

  4. A coastal hazards data base for the US Gulf Coast

    Energy Technology Data Exchange (ETDEWEB)

    Daniels, R.C. [ed.] [Oak Ridge National Lab., TN (United States). Carbon Dioxide Information Analysis Center]|[Univ. of Tennessee, Knoxville, TN (United States). Energy, Environment and Resources Center; Gornitz, V.M. [National Aeronautics and Space Administration, New York, NY (United States). Goddard Inst. for Space Studies; White, T.W. [Oak Ridge National Lab., TN (United States). Carbon Dioxide Information Analysis Center

    1994-06-01

    This document describes the contents of a digital data base that may be used to identify coastlines along the US Gulf Coast at risk to sea-level rise. The data base integrates point, line, and polygon data for the US Gulf Coast into 0.25{degree} latitude by 0.25{degree} longitude grid cells and into 1:2,000,000 digitized line segments that can be used by raster or vector geographic information systems (GIS) as well as by non-GIS data base systems. Each coastal grid cell and line segment contains data on elevation, geology, geomorphology, sea-level trends, shoreline displacement (erosion/accretion), tidal ranges, and wave heights. To allow for the identification of coastlines at risk from sea-level rise, 7 of the 22 original data variables in this data base were classified by vulnerability and used to create 7 relative risk variables. These relative risk variables range in value from 1 to 5 and may be used to calculate a coastal vulnerability index for each grid cell and/or line segment. The data for these 29 variables (i.e., the 22 original variables and 7 risk variables) have been placed into the following data formats: (1) Gridded polygon data for the 22 original data variables. Data include elevation, geology, geomorphology, sea-level trends, shoreline displacement (erosion/accretion), tidal ranges, and wave heights. (2) Gridded polygon data for the seven classified risk variables. The risk variables are classified versions of: mean coastal elevation, geology, geomorphology, local subsidence trend, mean shoreline displacement, maximum tidal range, and maximum significant wave height. (3) 1:2,000,000 line segment data containing the 29 data variables (the 22 original data variables and the seven classified risk variables). (4) Supplemental point data for the stations used in calculating the sea-level trend and tidal range data sets. (5) Supplemental line segment data containing a 1:2,000,000 digitized coastline of the US Gulf Coast as defined by this document.

  5. Mesozooplankton biomass and abundance in Cyprus coastal waters and comparison with the Aegean Sea (eastern Mediterranean

    Directory of Open Access Journals (Sweden)

    C. C.S. HANNIDES

    2015-07-01

    Full Text Available Here we conduct the first comprehensive assessment of mesozooplankton abundance, biomass, and taxa composition in Cyprus coastal waters (Levantine Sea.  Mesozooplankton abundance and biomass sampled at several locations around the island ranged from 153 – 498 individuals m-3 and 0.7 – 5.2 mg dry weight m-3, respectively, with significantly larger biomass observed in winter-early spring (March than in summer (September.  The community was dominated by calanoid and cyclopoid copepods throughout the year (80% of total numbers, with higher abundances of predatory taxa (chaetognaths and medusae in winter and cladocerans in summer.  Overall, we find that coastal mesozooplankton communities around Cyprus appear to be more similar to communities in offshore waters or those around the island of Rhodes than to communities along the mainland Levantine coast.  We further highlight regional differences in the eastern Mediterranean by comparing our data with mesozooplankton in the western Aegean (Saronikos Gulf and northeastern Aegean Sea (NEA.  Distinct spatial differences were observed, for example anthropogenic influences in the Saronikos Gulf and the outflow of Modified Black Sea Water in the NEA drove generally greater biomass and abundance in these regions.  Overall, our comparison supports the concept of a latitudinal gradient in oligotrophy in the eastern Mediterranean, with ultra-oligotrophic conditions found in the Levantine Sea.

  6. Crustal structure of the Eastern Gulf of Mexico

    Science.gov (United States)

    Nwafor, Emeka

    The Gulf of Mexico initiated in the Late Triassic as South America and Africa separated from North America during the break up of Pangea. Previous studies indicate three models for the opening of the GOM. These include counter clockwise rotation of the Yucatan Block, rotation of the Yucatan Block about the same pole of rotation as those describing seafloor spreading in the central North Atlantic, and clockwise rotation of the Yucatan Block. There is much debate about the margin type and the crustal structure of the Eastern Gulf of Mexico (EGOM), especially below the depth of 6 km where crustal structure is poorly imaged on seismic reflection data. Two 2.5-D forward gravity and magnetic models across the margin are presented. These are constrained by basement picks from sparse seismic reflection and refraction data, spectral analysis of gravity data to determine the depth to source, magnetic susceptibility derived from results from other margins, the empirical relationship between P-wave velocity and density, and crustal scale isostatic modeling. The models, combined with a kinematic reconstruction of the GOM, show that: 1) it is a rifted margin; 2) the point where the Moho deepens downward from ˜17 km to ˜32 km is approximately 50 km outboard of the topographic shelf edge; 3) the carbonate bank retreated by several kilometers from its original termination due to the action of contourite currents; 4) extension and subsidence was accommodated with little shallow brittle faulting; 5) oceanic lithosphere is possibly outboard of the EGOM continental slope.

  7. Coastal Vulnerability Index (CVI) for Gulf Islands National Seashore (guis_shore)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A coastal vulnerability index (CVI) was used to map the relative vulnerability of the coast to future sea-level rise within Gulf Islands National Seashore in...

  8. Coastal Vulnerability Index (CVI) for Gulf Islands National Seashore (guis_shore)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A coastal vulnerability index (CVI) was used to map the relative vulnerability of the coast to future sea-level rise within Gulf Islands National Seashore in...

  9. Regional stratigraphy and subsurface geology of Cenozoic deposits, Gulf Coastal Plain, south-central United States

    Science.gov (United States)

    Hosman, R.L.

    1991-01-01

    The Gulf Coast Regional Aquifer-System Analysis includes all major aquifer systems in Cenozoic deposits in the Gulf Coastal Plain in the States of Arkansas, Illinois, Kentucky, Louisiana, Mississippi, Missouri, Tennessee, Texas, and small areas in Alabama and Florida (western panhandle area), an area of about 290,000 square miles. The Gulf Coast geosyncline and the Mississippi embayment were the major depocenters for the Tertiary and Quaternary deposits that form the framework for the aquifer systems.

  10. Coastal Kelvin waves and dynamics of Gulf of Aden eddies

    Science.gov (United States)

    Valsala, Vinu K.; Rao, Rokkam R.

    2016-10-01

    The Gulf of Aden (GA) is a small semi-enclosed oceanic region between the Red Sea and the western Arabian Sea. The GA is characterised with westward propagating cyclonic and anti-cyclonic eddies throughout the year. The genesis and propagation of these eddies into the GA have been the focus of several studies which concluded that oceanic instabilities (both barotropic and baroclinic) as well as the Rossby waves from the Arabian Sea are the responsible mechanisms for the presence and maintenance of these eddies. Using a high-resolution (~11 km) reduced gravity hydrodynamic layered model with controlled lateral boundary conditions at the three sides of the GA here we show yet another factor, the coastally propagating Kelvin waves along the coastal Arabia (coasts of Oman and Yemen), is also critically important in setting up a favourable condition for the oceanic instabilities and sustenance of meso-scale eddies in the GA. These Kelvin waves at both seasonal and intra-seasonal time scales are found play an important role in the timing and amplitudes of eddies observed in the GA.

  11. Estimating the Provision of Ecosystem Services by Gulf of Mexico Coastal Wetlands.

    Science.gov (United States)

    Gulf of Mexico (GOM) coastal wetlands contribute to human well-being by providing many ecosystem services (e.g., commercial and recreational fishery support, protection of coastal communities from storm surge, water quality improvement, and carbon sequestration). The GOM region c...

  12. Coastal vulnerability assessment of the Northern Gulf of Mexico to sea-level rise and coastal change

    Science.gov (United States)

    Pendleton, E.A.; Barras, J.A.; Williams, S.J.; Twichell, D.C.

    2010-01-01

    A coastal vulnerability index (CVI) was used to map the relative vulnerability of the coast to future sea-level rise along the Northern Gulf of Mexico from Galveston, TX, to Panama City, FL. The CVI ranks the following in terms of their physical contribution to sea-level rise-related coastal change: geomorphology, regional coastal slope, rate of relative sea-level rise, historical shoreline change rate, mean tidal range, and mean significant wave height. The rankings for each variable are combined and an index value is calculated for 1-kilometer grid cells along the coast. The CVI highlights those regions where the physical effects of sea-level rise might be the greatest. The CVI assessment presented here builds on an earlier assessment conducted for the Gulf of Mexico. Recent higher resolution shoreline change, land loss, elevation, and subsidence data provide the foundation for a better assessment for the Northern Gulf of Mexico. The areas along the Northern Gulf of Mexico that are likely to be most vulnerable to sea-level rise are parts of the Louisiana Chenier Plain, Teche-Vermillion Basin, and the Mississippi barrier islands, as well as most of the Terrebonne and Barataria Bay region and the Chandeleur Islands. These very high vulnerability areas have the highest rates of relative sea-level rise and the highest rates of shoreline change or land area loss. The information provided by coastal vulnerability assessments can be used in long-term coastal management and policy decision making.

  13. Postglacial development of the eastern Gulf of Finland: from Pleistocene glacial lake basins to Holocene lagoon systems

    Science.gov (United States)

    Ryabchuk, Daria; Sergeev, Alexander; Kotilainen, Aarno; Hyttinen, Outi; Grigoriev, Andrey; Gerasimov, Dmitry; Anisimov, Mikhail; Gusentsova, Tatiana; Zhamoida, Vladimir; Amantov, Aleksey; Budanov, Leonid

    2016-04-01

    Despite significant amount of data, there are still lots of debatable questions and unsolved problems concerning postglacial geological history of the Eastern Gulf of Finland, the Baltic Sea. Among these problems are: 1) locations of the end moraine and glacio-fluvial deposits; 2) time and genesis of the large accretion forms (spits, bars, dunes); 3) basinwide correlations of trangression/regression culminations with the other parts of the Baltic Sea basin; 4) study of salinity, timing, frequency and intensity of Holocene saline water inflows and their links of sedimentation processes associated with climate change. Aiming to receive new data about regional postglacial development, the GIS analyses of bottom relief and available geological and geophysical data was undertaken, the maps of preQuaternary relief, moraine and Late Pleistocene surfaces, glacial moraine and Holocene sediments thicknesses were compiled. High-resolution sediment proxy study of several cores, taken from eastern Gulf of Finland bottom, allows to study grain-size distribution and geochemical features of glacial lake and Holocene sediments, to reveal sedimentation rates and paleoenvironment features of postglacial basins. Interdisciplinary geoarcheological approaches offer new opportunities for studying the region's geological history and paleogeography. Based on proxy marine geological and coastal geoarcheological studies (e.g. off-shore acoustic survey, side-scan profiling and sediment sampling, on-shore ground-penetrating radar (GPR SIR 2000), leveling, drilling, grain-size analyses and radiocarbon dating and archeological research) detailed paleogeographical reconstruction for three micro-regions - Sestroretsky and Lahta Lowlands, Narva-Luga Klint Bay and Southern Ladoga - were compiled. As a result, new high resolution models of Holocene geological development of the Eastern Gulf of Finland were received. Model calibration and verification used results from proxy geoarcheological research

  14. Shorebird Use of Coastal Wetland and Barrier Island Habitat in the Gulf of Mexico

    Directory of Open Access Journals (Sweden)

    Kim Withers

    2002-01-01

    Full Text Available The Gulf Coast contains some of the most important shorebird habitats in North America. This area encompasses a diverse mixture of estuarine and barrier island habitats with varying amounts of freshwater swamps and marshes, bottomland hardwood forests, and coastal prairie that has been largely altered for rice and crawfish production, temporary ponds, and river floodplain habitat. For the purposes of this review, discussion is confined to general patterns of shorebird abundance, distribution, and macro- and microhabitat use in natural coastal, estuarine, and barrier island habitats on the Gulf of Mexico Coast. The following geographic regions are considered: Northwestern Gulf (Rio Grande to Louisiana-Mississippi border, Northeastern Gulf (Mississippi to Florida Keys, and Mexico (Rio Grande to Cabo Catoche [Yucatan Strait].

  15. Sea turtle distribution along the boundary of the Gulf Stream current off eastern Florida

    Science.gov (United States)

    Hoffman, W.; Fritts, T.H.

    1982-01-01

    Aerial surveys, out to 222 km off the east coast of central Florida during August 1980, revealed that marine turtles were distributed in a narrow zone west of the Gulf Stream. Of 255 loggerhead turtles, Caretta caretta, only three were observed east of the western boundary of the Gulf Stream. Radiometric thermometry revealed that the waters occupied by most Caretta were markedly cooler than the nearby waters of the Gulf Stream. Of 18 leatherback turtles, Dermochelys coriacea, all were seen west of the Gulf Stream in waters less than 70 m in depth. Marine turtles off eastern Florida are confined seasonally to nearshore waters west of the Gulf Stream. The records of Dermochelys in nearshore waters are in contrast with a deep water oceanic ecology often hypothesized for this species.

  16. Improved Oil Recovery from Upper Jurassic Smackover Carbonates through the Application of Advanced Technologies at Womack Hill Oil Field, Choctaw and Clarke Counties, Alabama, Eastern Gulf Coastal Plan (Phase II)

    Energy Technology Data Exchange (ETDEWEB)

    Ernest A. Mancini; Joe Benson; David Hilton; David Cate; Lewis Brown

    2006-05-29

    The principal research efforts for Phase II of the project were drilling an infill well strategically located in Section 13, T. 10 N., R. 2 W., of the Womack Hill Field, Choctaw and Clarke Counties, Alabama, and obtaining fresh core from the upper Smackover reservoir to test the feasibility of implementing an immobilized enzyme technology project in this field. The Turner Land and Timber Company 13-10 No. 1 well was successfully drilled and tested at a daily rate of 132 barrels of oil in Section 13. The well has produced 27,720 barrels of oil, and is currently producing at a rate of 60 barrels of oil per day. The 13-10 well confirmed the presence of 175,000 barrels of attic (undrained) oil in Section 13. As predicted from reservoir characterization, modeling and simulation, the top of the Smackover reservoir in the 13-10 well is structurally high to the tops of the Smackover in offsetting wells, and the 13-10 well has significantly more net pay than the offsetting wells. The drilling and testing of the 13-10 well showed that the eastern part of the field continues to have a strong water drive and that there is no need to implement a pressure maintenance program in this part of the Womack Hill Field at this time. The success achieved in drilling and testing the 13-10 infill well demonstrates the benefits of building a geologic model to target areas in mature fields that have the potential to contain undrained oil, thus increasing the productivity and profitability of these fields. Microbial cultures that grew at 90 C and converted ethanol to acid were recovered from fresh cuttings from the Smackover carbonate reservoir in an analogous field to the Womack Hill Field in southwest Alabama; however, no viable microorganisms were found in the Smackover cores recovered from the drilling of the 13-10 well in Womack Hill Field. Further evaluation is, therefore, required prior to implementing an immobilized enzyme technology project in the Womack Hill Field.

  17. Savannah River Region: Transition between the Gulf and Atlantic Coastal Plains. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Zullo, V.A.; Harris, W.B.; Price, V. [eds.

    1990-12-31

    The focus of the this conference of Coastal Plains geologists was on the Savannah River region of Georgia and South Carolina, and particularly on the geology of the US Department of Energy`s 300 square mile Savannah River Site (SRS) in western South Carolina. Current geological studies indicate that the Mesozoic-Cenozoic section in the Savannah River region is transitional between that of the Gulf Coastal Plain to the southwest and that of the Atlantic Coastal Plain to the northeast. With the transitional aspect of the region as its theme, the first session was devoted to overviews of Cretaceous and Paleogene geology in the Gulf and Atlantic Coastal Plains. Succeeding presentations and resulting discussions dealt with more specific problems in structural, lithostratigraphic, hydrological, biostratigraphic, and cyclostratigraphic analysis, and of correlation to standard stratigraphic frameworks. For these conference proceedings, individual papers have been processed separately for the Energy Data Base.

  18. U.S. Coastal Relief Model - Western Gulf of Mexico

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NGDC's U.S. Coastal Relief Model (CRM) provides the first comprehensive view of the U.S. coastal zone integrating offshore bathymetry with land topography into a...

  19. U.S. Coastal Relief Model - Central Gulf of Mexico

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NGDC's U.S. Coastal Relief Model (CRM) provides the first comprehensive view of the U.S. coastal zone integrating offshore bathymetry with land topography into a...

  20. EAARL Coastal Topography - Northern Gulf of Mexico, 2007: Bare Earth

    Science.gov (United States)

    Smith, Kathryn E.L.; Nayegandhi, Amar; Wright, C. Wayne; Bonisteel, Jamie M.; Brock, John C.

    2009-01-01

    These remotely sensed, geographically referenced elevation measurements of Lidar-derived bare earth (BE) topography were produced as a collaborative effort between the U.S. Geological Survey (USGS), Florida Integrated Science Center (FISC), St. Petersburg, FL; the National Park Service (NPS), Gulf Coast Network, Lafayette, LA; and the National Aeronautics and Space Administration (NASA), Wallops Flight Facility, VA. The purpose of this project is to provide highly detailed and accurate datasets of select barrier islands and peninsular regions of Louisiana, Mississippi, Alabama, and Florida, acquired on June 27-30, 2007. The datasets are made available for use as a management tool to research scientists and natural resource managers. An innovative airborne Lidar instrument originally developed at the NASA Wallops Flight Facility, and known as the Experimental Advanced Airborne Research Lidar (EAARL), was used during data acquisition. The EAARL system is a raster-scanning, waveform-resolving, green-wavelength (532-nanometer) Lidar designed to map near-shore bathymetry, topography, and vegetation structure simultaneously. The EAARL sensor suite includes the raster-scanning, water-penetrating full-waveform adaptive Lidar, a down-looking red-green-blue (RGB) digital camera, a high-resolution multi-spectral color infrared (CIR) camera, two precision dual-frequency kinematic carrier-phase GPS receivers, and an integrated miniature digital inertial measurement unit which provide for submeter georeferencing of each laser sample. The nominal EAARL platform is a twin-engine Cessna 310 aircraft, but the instrument may be deployed on a range of light aircraft. A single pilot, a Lidar operator, and a data analyst constitute the crew for most survey operations. This sensor has the potential to make significant contributions in measuring sub-aerial and submarine coastal topography within cross-environmental surveys. Elevation measurements were collected over the survey area using

  1. EAARL Coastal Topography - Northern Gulf of Mexico, 2007: First Surface

    Science.gov (United States)

    Smith, Kathryn E.L.; Nayegandhi, Amar; Wright, C. Wayne; Bonisteel, Jamie M.; Brock, John C.

    2009-01-01

    These remotely sensed, geographically referenced elevation measurements of Lidar-derived first surface (FS) elevation data were produced as a collaborative effort between the U.S. Geological Survey (USGS), Florida Integrated Science Center (FISC), St. Petersburg, FL; the National Park Service (NPS), Gulf Coast Network, Lafayette, LA; and the National Aeronautics and Space Administration (NASA), Wallops Flight Facility, VA. The project provides highly detailed and accurate datasets of select barrier islands and peninsular regions of Louisiana, Mississippi, Alabama, and Florida, acquired June 27-30, 2007. The datasets are made available for use as a management tool to research scientists and natural resource managers. An innovative airborne Lidar instrument originally developed at the NASA Wallops Flight Facility, and known as the Experimental Advanced Airborne Research Lidar (EAARL), was used during data acquisition. The EAARL system is a raster-scanning, waveform-resolving, green-wavelength (532-nanometer) Lidar designed to map near-shore bathymetry, topography, and vegetation structure simultaneously. The EAARL sensor suite includes the raster-scanning, water-penetrating full-waveform adaptive Lidar, a down-looking red-green-blue (RGB) digital camera, a high-resolution multi-spectral color infrared (CIR) camera, two precision dual-frequency kinematic carrier-phase GPS receivers, and an integrated miniature digital inertial measurement unit which provide for submeter georeferencing of each laser sample. The nominal EAARL platform is a twin-engine Cessna 310 aircraft, but the instrument may be deployed on a range of light aircraft. A single pilot, a Lidar operator, and a data analyst constitute the crew for most survey operations. This sensor has the potential to make significant contributions in measuring sub-aerial and submarine coastal topography within cross-environmental surveys. Elevation measurements were collected over the survey area using the EAARL system

  2. EAARL Coastal Topography - Northern Gulf of Mexico, 2007: First surface

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A first surface elevation map (also known as a Digital Elevation Model, or DEM) of the northern Gulf of Mexico barrier islands and Naval Live Oaks was produced from...

  3. EAARL Coastal Topography - Northern Gulf of Mexico, 2007: Bare earth

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A bare earth elevation map (also known as a Digital Elevation Model, or DEM) of the northern Gulf of Mexico barrier islands and Naval Live Oaks was produced from...

  4. EAARL Coastal Topography - Northern Gulf of Mexico, 2007: First surface

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A first surface elevation map (also known as a Digital Elevation Model, or DEM) of the northern Gulf of Mexico barrier islands and Naval Live Oaks was produced from...

  5. EAARL Coastal Topography - Northern Gulf of Mexico, 2007: Bare earth

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A bare earth elevation map (also known as a Digital Elevation Model, or DEM) of the northern Gulf of Mexico barrier islands and Naval Live Oaks was produced from...

  6. SEDIMENT HAZARD ASSESSMENT FOR NEAR-COASTAL AREAS OF THE GULF OF MEXICO

    Science.gov (United States)

    Sediment contamination is a major problem in many coastal areas in the U.S. and has emerged as an important ecological issue for several geographic areas. Sediment chemical and biological quality is unknown in many areas of the Gulf of Mexico. To provide some information on this ...

  7. SEDIMENT HABITAT ASSESSMENT FOR TARGETED NEAR-COASTAL AREAS OF THE GULF OF MEXICO: A SUMMARY

    Science.gov (United States)

    Lewis, Michael A. In press. Sediment Habitat Assessment for Targeted Near-Coastal Areas of the Gulf of Mexico: A Summary. In: Estuarine Indicators Workshop Proceedings. CRC Press, Boca Raton, FL. 25 p. (ERL,GB 1201). Sediment chemical and biological quality is summarized ...

  8. Coastal change and hypoxia in the northern Gulf of Mexico: Part I

    Directory of Open Access Journals (Sweden)

    2007-01-01

    Full Text Available The Committee on Environment and Natural Resources (CENR has identified the input of nutrient-rich water from the Mississippi/Atchafalaya River Basin (MARB as the prime cause of hypoxia in the northern Gulf of Mexico and the prime means for its control. A Watershed Nutrient Task Force was formed to solve the hypoxia problem by managing the MARB catchment. However, the hypoxic zone is also experiencing massive physical, hydrological, chemical and biological changes associated with an immense river-switching and delta-building event that occurs here about once a millennium. Coastal change induced hypoxia in the northern Gulf of Mexico prior to European settlement. It is recommended that for further understanding and control of Gulf hypoxia the Watershed Nutrient Task Force adopt a truly holistic environmental approach which includes the full effects of this highly dynamic coastal area.

  9. Coastal-trapped Motions off Southern Tamaulipas and Northern Veracruz, Western Gulf of Mexico

    Science.gov (United States)

    Rivas, D.

    2015-12-01

    Four months of observations from a near-coastal mooring deployed off southern Tamaulipas-northern Veracruz coast (western Gulf of Mexico) during winter 2012-2013 provides velocity and pressure series in a coastal region where apparently no in-situ measurements have been formally reported. The measurements show numerous events of intense alongshore velocities with magnitudes typically exceeding 80 cm/s, associated with intensified winds associated with the cold fronts invading the western Gulf during fall-winter, via coastal-trapped motions coming from northern locations. These motions induce a coastal jet that modulates the regional along-shelf transports. This notion is corroborated by an analytical coastal-trapped wave (CTW) model which explains most of the variability of the sea level and the alongshore barotropic velocity observed in the mooring, and which can also be used to estimate how much of the observed variance is generated in remote locations along the northern coast of the Gulf of Mexico.

  10. Net primary productivity, upwelling and coastal currents in the Gulf of Ulloa, Baja California, Mexico

    Directory of Open Access Journals (Sweden)

    E. González-Rodríguez

    2011-09-01

    Full Text Available The Gulf of Ulloa, a highly productive area off the western coast of Baja California Peninsula, is examined for five successive years (2003–2007 by using satellite data and seasonal net primary productivity estimates obtained by a vertical generalized production model. The results clearly identify a seasonal signal of coastal upwelling in productivity estimates. Highest values occur from May to June and sometimes July. We also find influence of an equatorward coastal current able of transporting water from neighboring north upwelling areas to the Gulf of Ulloa in winter–spring. This flow contributes to increase the seasonal net primary productivity. The opposite occurs in summer, when a warm poleward current of tropical characteristics arrives to the region. Our findings reveal that such warm coastal current suppressed the productivity in the whole.

  11. The Gulf of Mexico Coastal Ocean Observing System: A Gulf Science Portal

    Science.gov (United States)

    Howard, M.; Gayanilo, F.; Kobara, S.; Jochens, A. E.

    2013-12-01

    The Gulf of Mexico Coastal Ocean Observing System's (GCOOS) regional science portal (gcoos.org) was designed to aggregate data and model output from distributed providers and to offer these, and derived products, through a single access point in standardized ways to a diverse set of users. The portal evolved under the NOAA-led U.S. Integrated Ocean Observing System (IOOS) program where automated largely-unattended machine-to-machine interoperability has always been a guiding tenet for system design. The web portal has a business unit where membership lists, new items, and reference materials are kept, a data portal where near real-time and historical data are held and served, and a products portal where data are fused into products tailored for specific or general stakeholder groups. The staff includes a system architect who built and maintains the data portal, a GIS expert who built and maintains the current product portal, the executive director who marshals resources to keep news items fresh and data manger who manages most of this. The business portal is built using WordPress which was selected because it appeared to be the easiest content management system for non-web programmers to add content to, maintain and enhance. The data portal is custom built and uses database, PHP, and web services based on Open Geospatial Consortium standards-based Sensor Observation Service (SOS) with Observations and Measurements (O&M) encodings. We employ a standards-based vocabulary, which we helped develop, which is registered at the Marine Metadata Interoperability Ontology Registry and Repository (http://mmisw.org). The registry is currently maintained by one of the authors. Products appearing in the products portal are primarily constructed using ESRI software by a Ph.D. level Geographer. Some products were built with other software, generally by graduate students over the years. We have been sensitive to the private sector when deciding which products to produce. While

  12. 2016 USACE National Coastal Mapping Program (NCMP) Gulf Coast Lidar and Imagery Acquisition - Texas, Louisiana, Mississippi, Alabama and Florida

    Data.gov (United States)

    Army Corps of Engineers, Department of the Army, Department of Defense — The Joint Airborne Lidar Bathymetry Technical Center of Expertise (JALBTCX) plans to perform a coastal survey along the Gulf Coast in 2016 with funding provided by...

  13. The 1982-1984 El Niño in the Gulf of California as seen in coastal zone color scanner imagery

    Science.gov (United States)

    SantamaríA-Del-Angel, Eduardo; Alvarez-Borrego, Saúl; Müller-Karger, Frank E.

    1994-04-01

    The 1982-1984 El Niño was well documented for the Gulf of California, primarily with sea level anomalies. However, owing to strong tidal and atmospheric forcing, the general effects on chlorophyll concentrations ([Chl]) and phytoplankton productivity (PP) are not clear. The literature reports low [Chl] and PP for the mouth region and high values for both variables in the central gulf and in the region of the midrift islands. No data were collected in situ in the northern gulf. Using monthly composites of coastal zone color scanner (CZCS) satellite imagery, we generated time series for 33 locations throughout the gulf. We calculated pigment concentration anomalies and derived a relative power index that provides a measure of the relationship between negative anomalies and El Niño episodes. Our analyses show that during 1978-1986, variability in phytoplankton biomass in the Gulf of California was not dominated by El Niño events. Rather, strong tidal mixing and upwelling in the interior of the gulf masked the effect of El Niño 1982-1984 that otherwise showed so clearly in other coastal ecosystems of the eastern Pacific. Lower pigment concentrations were in fact detected with the CZCS at and near the entrance of the gulf, where vertical mixing is not as strong. Locations in the central and northern gulf showed either a weak effect or no effect of El Niño. Ballenas Channel showed an exceptional behavior, with an increase of pigment concentrations toward the end of 1983. Despite the Ballenas Channel having the highest surface nutrient concentrations, pigment maxima there are not in general the highest of the gulf. The excess vertical turbulence in the channel leads to light limitation of phytoplankton. Reduced mixing at the end of 1983 promoted the increase of phytoplankton biomass in Ballenas Channel. Strong non-El Niño conditions in 1984 caused lower phytoplankton biomass in Ballenas Channel than during other years of the period analyzed.

  14. Anthropogenic pollution indicators in marine environment of the Eastern Part of the Gulf of Finland

    Science.gov (United States)

    Zhakovskaya, Zoya; Nikiforov, Vladimir; Mamontova, Varvara; Khoroshko, Larisa; Chernova, Ekaterina; Russkikh, Iana

    2014-05-01

    Pollution involving hazardous substances is considered one of the major problems affecting the state of the Baltic marine environment. However, assessment of the vast majority of the hazardous substances (including accepted as pollution indicators) in the environment have not been monitored in Russian Federation yet. Moreover there are no official guideline values for their presence or release in environment. For our investigation we have selected the organotin biocides and widespread pharmaceutical diclofenac. The study is focused on surface marine water and bottom sediments, collected from the eastern part of the Gulf of Finland during the navigation seasons of 2012-2013. Organotin compounds belong to a large group of key marine contaminants. They had been widely used in the world industry as antifouling paints, fungicides and biocides until the middle of 1980s. Tributyltin (TBT) and triphenyltin (TPhT) are the most hazardous of all organotin compounds, causing such biological effects as shell deformation, endocrine disruption, imposex and intersex phenomena at the concentration of 2 ng/L. The use of TBT in antifouling paints was banned within EU in 2003 and within Russian Federation in 2008. Monobutyltin (MBT), dibutyltin (DBT), tributyltin (TBT) and triphenyltin (TPhT) were analysed as ethyl derivatives using electron impact gas chromatography-mass spectrometry (GC-MS-EI) in single ion monitoring mode (SIM). TBT and TPhT were frequently found above MAC of 1.5 ng/L and 2 ng/g dw respectively in both water and bottom sediment samples collected from the Gulf of Finland water basin. The highest detected concentration detected mainly in coastal areas with dense ship traffic were 670 ng/L (TBT) in water samples, 440 ng/g dw (TBT), 160 ng/g dw (TPhT) in sediment samples. Potential risks from the environmental presence of pharmaceuticals and personal care products (PPCP), such as medicine, hormones, means of personal hygiene, etc. reveal in abnormal physiological

  15. Estimating occurrence and detection probabilities for stream-breeding salamanders in the Gulf Coastal Plain

    Science.gov (United States)

    Lamb, Jennifer Y.; Waddle, J. Hardin; Qualls, Carl P.

    2017-01-01

    Large gaps exist in our knowledge of the ecology of stream-breeding plethodontid salamanders in the Gulf Coastal Plain. Data describing where these salamanders are likely to occur along environmental gradients, as well as their likelihood of detection, are important for the prevention and management of amphibian declines. We used presence/absence data from leaf litter bag surveys and a hierarchical Bayesian multispecies single-season occupancy model to estimate the occurrence of five species of plethodontids across reaches in headwater streams in the Gulf Coastal Plain. Average detection probabilities were high (range = 0.432–0.942) and unaffected by sampling covariates specific to the use of litter bags (i.e., bag submergence, sampling season, in-stream cover). Estimates of occurrence probabilities differed substantially between species (range = 0.092–0.703) and were influenced by the size of the upstream drainage area and by the maximum proportion of the reach that dried. The effects of these two factors were not equivalent across species. Our results demonstrate that hierarchical multispecies models successfully estimate occurrence parameters for both rare and common stream-breeding plethodontids. The resulting models clarify how species are distributed within stream networks, and they provide baseline values that will be useful in evaluating the conservation statuses of plethodontid species within lotic systems in the Gulf Coastal Plain.

  16. Genetic assessment of meiobenthic community composition and spatial distribution in coastal sediments along northern Gulf of Mexico.

    Science.gov (United States)

    Brannock, Pamela M; Wang, Lei; Ortmann, Alice C; Waits, Damien S; Halanych, Kenneth M

    2016-08-01

    Meiobenthic (meiofauna and micro-eukaryotes) organisms are important contributors to ecosystem functioning in aquatic environments through their roles in nutrient transport, sediment stability, and food web interactions. Despite their ecological importance, information pertaining to variation of these communities at various spatial and temporal scales is not widely known. Many studies in the Gulf of Mexico (GOM) have focused either on deep sea or continental shelf areas, while little attention has been paid to bays and coastal regions. Herein, we take a holistic approach by using high-throughput sequencing approaches to examine spatial variation in meiobenthic communities within Alabama bays and the coastal northern GOM region. Sediment samples were collected along three transects (Mississippi Sound: MS, FOCAL: FT, and Orange Beach: OB) from September 2010 to April 2012 and community composition was determined by metabarcoding the V9 hypervariable region of the nuclear18S rRNA gene. Results showed that Stramenopiles (diatoms), annelids, arthropods (copepods), and nematodes were the dominate groups within samples, while there was presence of other phyla throughout the dataset. Location played a larger role than time sampled in community composition. However, samples were collected over a short temporal scale. Samples clustered in reference to transect, with the most eastern transect (OB) having a distinct community composition in comparison to the other two transects (MS and FT). Communities also differed in reference to region (Bay versus Shelf). Bulk density and percent inorganic carbon were the only measured environmental factors that were correlated with community composition.

  17. Spatial and temporal variability in the δ18Ow and salinity compositions of Gulf of Maine coastal surface waters

    Science.gov (United States)

    Whitney, Nina M.; Wanamaker, Alan D.; Kreutz, Karl J.; Introne, Douglas S.

    2017-04-01

    Hydrographic variability and dynamics in the Gulf of Maine are examined through the investigation of δ18Ow and salinity properties of coastal surface waters. Data from Gulf of Maine waters sampled over a decade, from 2003 to 2015, including a suite of samples that were collected monthly from April 2014 to March 2015, are presented. These water samples fall on a mixing line between Maine River Water (MRW) and Scotian Shelf Water (SSW). However, slope waters likely also contribute to these surface waters. The seasonal variability in water samples collected during 2014 and 2015 indicates the strong influence of river runoff on coastal Gulf of Maine surface water properties. The coastal Gulf of Maine mixing line presented in this paper is a needed baseline for reconstructing hydrographic variability in bicarbonates using oxygen isotopes.

  18. 77 FR 39648 - Atlantic Highly Migratory Species; Commercial Gulf of Mexico Non-Sandbar Large Coastal Shark Fishery

    Science.gov (United States)

    2012-07-05

    ...; Commercial Gulf of Mexico Non- Sandbar Large Coastal Shark Fishery AGENCY: National Marine Fisheries Service...; closure. SUMMARY: NMFS is closing the commercial fishery for non-sandbar large coastal sharks (LCS) in the... Peter Cooper 301-427-8503; fax 301-713-1917. SUPPLEMENTARY INFORMATION: The Atlantic shark fisheries...

  19. 76 FR 5326 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; King and Spanish Mackerel Coastal...

    Science.gov (United States)

    2011-01-31

    ..., Gulf of Mexico, and South Atlantic; King and Spanish Mackerel Coastal Migratory Pelagic Fishery Off the... future access to the king and Spanish mackerel components of the coastal migratory pelagics fishery..., the Council recommended a new control date of September 17, 2010, for king and Spanish mackerel....

  20. Estuarine infill and coastal progradation, southern van diemen gulf, northern Australia

    Science.gov (United States)

    Woodroffe, C. D.; Mulrennan, M. E.; Chappell, J.

    1993-03-01

    There are several estuaries associated with the pronouncedly seasonal rivers which drain northwards from the Middle Proterozoic sandstone Arnhem Land plateau, and the Tertiary Koolpinyah land surface, into the macrotidal van Diemen Gulf, in the Northern Territory of Australia. The Holocene development of these, investigated in greatest detail for the South Alligator River with an upland catchment of > 10,000 km 2. through drilling, palynology and radiocarbon dating, comprises both estuarine infill and coastal progradation. Three phases of estuarine infill can be recognised: (i) a transgressive phase (8000-6800 years B.P.) of marine incursion; (ii) a big swamp phase (6800-5300 years B.P.) of widespread mangrove forest development; and (iii) a sinuous/cuspate phase of floodplain development since 5300 years B.P., during which the tidal river has meandered and reworked earlier estuarine sediments. Since 6000 years B.P., the South Alligator coastal plain has prograded at a decelerating rate, with two phases of chenier ridge formation. A similar pattern of estuarine infill, and decelerating coastal plain progradation, is demonstrated for the Adelaide and Mary Rivers, both with catchments of > 6000 km 2. The southern shore of van Diemem Gulf appears to have changed its overall position little during the last 2000 years. The major source for the clay, silt and fine sands which have infilled the estuary and coastal plain has been from seaward. Dispite the similarity of development, coastal sediment build up has had different effects on the morphology of each tidal river. The Adelaide has undergone a major diversion and no longer flows directly into van Diemen Gulf, but occupies a former fluvial course, and the Mary has been blocked entirely, and its former estuarine palaeochannels have been infilled with tide-transported sediment.

  1. GULF - Coastal Vulnerability to Sea-Level Rise: U.S. Gulf Coast

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The goal of this project is to quantify, at the National scale, the relative susceptibility of the Nation's coast to sea-level rise through the use of a coastal...

  2. Evolution of the Sedimentary Basin Within the Eastern Eez Polygon at the Gulf of Mexico

    Science.gov (United States)

    Valle, S.; Mortera-Gutierrez, C. A.; Bandy, W. L.; Escobar-Briones, E. G.; Perez, D. A.

    2013-05-01

    This study shows the seafloor structures and magnetic anomalies inside the eastern EEZ polygon at the Gulf of Mexico. The objective of this study is to examine the previous hypothesis of the Gulf of Mexico opening, based on the seafloor magnetic character. Researchers from the "Instituto de Ciencias del Mar y Limnología" at UNAM, collected , multibeam bathymetric data, high-resolution seismic reflection and magnetic profiles along 37 E-W transects during two campaigns on board the UNAM vessel, BO JUSTO SIERRA, SIGSBEE-11 in 2008 and SIGSBEE-13 in 2010. Results of the bathymetry data gathered with the EM300 multibeam echo sounder (Kongsberg) and processed with the software Caraibes from IFREMER has generated a bathymetry chart of seafloor at the Eastern Polygon, and a mosaic of back-scattering images. The high-resolution seismic profiles gathered with the subbottom profiler TOPAS PS-18 (Kongsberg) provide information on the stratigraphy sediment packages across this polygon and across the deep Mississippi Canyon. The magnetic anomalies are reduced from the data gathered with a proton-precession magnetometer, G877 (GEOMETRICS). The anomalies are modeled, based on a N_S rift at the Gulf central sector. The bathymetric chart and reflectivity mosaics of SIGSBEE-11 and SIGSBEE-13 documented the smooth relief of the seabed slope toward the Gulf central sector and abrupt morphological features associated to the meanders of the Mississippi Canyon that trend to the East. The multibeam bathymetry chart shows a relief depth that goes from 2,900 to 3,400 m from north to south. Meanders are observed in the seabed within the Eastern Polygon which is related to turbidity currents from the Mississippi River, and having a trend from west to east. The relief of the canyon shows channels with widths between 400 and 1800 m, and canyon depths up to 80 m. The high-resolution seismic sections, show well defined stratigraphy packages, where clear sediment strata are interrupted by

  3. Estimating Sea Surface Salinity in Coastal Waters of the Gulf of Mexico Using Visible Channels on SNPP-VIIRS

    Science.gov (United States)

    2014-01-01

    surface salinity estimates for the Northern Gulf of Mexico . In situ salinity data collected from six coastal moorings were compared to calibrated, geo...34Geographic and hydrodynamic characteristics of shallow coastal lagoons ," Marine Geology 88, 187-199 (1989) [3] Gordon, H.R., and Wang, M., "Retrieval...1. HEPORJ OI\\JE (DD-MM-YYYY) 30-07-2014 REPORT TYPE Conference Proceeding 4. TITLE AND SUBTITLE Estimating Sea Surface Salinity in Coastal

  4. Coastal debris analysis in beaches of Chonburi Province, eastern of Thailand as implications for coastal conservation.

    Science.gov (United States)

    Thushari, Gajahin Gamage Nadeeka; Chavanich, Suchana; Yakupitiyage, Amararatne

    2017-03-15

    This study quantified coastal debris along 3 beaches (Angsila, Bangsaen, Samaesarn) in eastern coast of Thailand. Debris samples were collected from lower and upper strata of these beaches during wet and dry seasons. The results showed that Bangsaen had the highest average debris density (15.5m(-2)) followed by Samaesarn (8.10m(-2)), and Angsila (5.54m(-2)). Among the 12 debris categories, the most abundant debris type was plastics (>45% of the total debris) in all beach locations. Coastal debris distribution was related to economic activities in the vicinity. Fishery and shell-fish aquaculture activities were primary sources of debris in Angsila while tourism activities were main sources in Bangsaen and Samaesarn. Site-specific pollution control mechanisms (environmental awareness, reuse and recycling) are recommended to reduce public littering. Management actions in Angsila should focus on fishery and shell-fish culture practices, while Bangsaen and Samaesarn should be directed toward leisure activities promoting waste management. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Structural geometry in the eastern Pyrenees and western Gulf of Lion (Western Mediterranean)

    Science.gov (United States)

    Mauffret, Alain; Durand de Grossouvre, Bernard; Tadeu Dos Reis, Antonio; Gorini, Christian; Nercessian, Alex

    2001-11-01

    We present new seismic data from the Gulf of Lion located east of the Pyrenees on the continental shelf of the Mediterranean Sea. The deep penetration LISA (Ligurian-Sardinia Sea) seismic lines, the shots of the LISA cruise recorded on land, and the high definition ELF seismic sections allow us to present a complete picture of the tectonics in this area from the surface to the Moho level, and also to document late Miocene-early Pliocene extensional tectonics in the area. Previous studies show a prominent thinning of the crust observed from the Pyrenees towards the Gulf of Lion. The Moho depth varies from 48 km beneath the Axial Range crust (thickened during the Pyrenean Eocene Orogeny) to 21 km below the Catalan Basin in the Gulf of Lion. This crustal thinning occurred mainly during the early Miocene extension of the Mediterranean Sea. Balanced reconstructed geological sections derived from reflection and refraction seismic data allow us to evaluate the stretching factors at the crustal level. A maximum extension of 25 km is computed for the Catalan Basin area. This extension is related to detachments that penetrate the crust as deep as 11 km to the base of the brittle crust. These intra basement detachments have been confused in the past with the Paleozoic acoustic basement. The detachments show a clear listric shape and the geometry of horst and grabens can be explained by a hanging wall and footwall configuration with isostatic rebound of the footwall. The uplift in the Eastern Pyrenees (Albères and Canigou Massifs), on the other hand, is related to the late Miocene-early Pliocene extension we mapped in the area. These elevated features, probably formed by isostatic rebound, are surrounded by deep basins such as the Roussillon and El Empordà depressions. A 1.7 km uplift during the late Miocene-early Pliocene is computed in the offshore part of the Albères Massif. The cause of this Late Miocene-early Pliocene extension is not well explained although an uplift

  6. Effect of coastal-trapped waves and wind on currents and transport in the Gulf of California

    Science.gov (United States)

    Gutiérrez, Manuel O.; López, Manuel; Candela, Julio; Castro, Rubén.; Mascarenhas, Affonso; Collins, Curtis A.

    2014-08-01

    Subsurface pressure (SsP) observations from stations inside and outside of the Gulf of California (GC) are used to analyze the relationship between low-frequency currents, temperature, and transport inside the GC and intraseasonal coastal-trapped waves (CTWs), which propagate poleward along the coast toward the GC. Correlation functions and coherences of SsP stations were consistent with intraseasonal CTWs splitting in two at the mouth of the gulf: one part enters the gulf, propagates around the gulf, and eventually, toward the mouth, and another part that appears to "jump" the mouth of the gulf and travels poleward along the west coast of the peninsula. The correlation and coherence estimates of SsP at Manzanillo with currents showed that downwelling CTWs generated along-gulf current anomalies toward the head of the gulf at the mainland shelf of the mouth, whereas at Ballenas Channel sill (San Lorenzo sill) these waves generated current anomalies toward the mouth near the surface (bottom). At the San Lorenzo (SL) sill, downwelling CTWs increased the near-bottom (˜400 m) temperature and reduced the bottom transport of deep, fresher, and colder water that flows toward the head of the gulf. Cross-Calibrated Multiplatform winds were used to investigate their relationship with currents. The first empirical orthogonal function of the along-gulf wind stress showed that wind blowing toward the head of the gulf generated a reduction of bottom transport toward the head of the gulf through the SL sill, and intensified surface geostrophic current fluctuations toward the head of the gulf. There was also significant correlation between inflow bottom transport and outflow surface geostrophic velocities averaged across the gulf, consistent with the exchange pattern for the Northern Gulf.

  7. Abstracts from "Coastal Marsh Dieback in the Northern Gulf of Mexico: Extent, Causes, Consequences, and Remedies

    Science.gov (United States)

    Stewart, Robert E.; Proffitt, C. Edward; Charron, Tammy Michelle

    2001-01-01

    In the spring of 2000, scientists discovered a new and unprecedented loss of salt marsh vegetation in coastal Louisiana and other areas along the northern coast of the Gulf of Mexico. This dieback of salt marsh vegetation, sometimes called the brown marsh phenomenon', primarily involved the rapid browning and dieback of smooth cordgrass (Spanina alterniflora). Coastal Louisiana has already undergone huge, historical losses of coastal marsh due to both human-induced and natural factors, and the current overall rate of wetland loss (25-35 sq mi 65-91 SQ KM each year) stands to threaten Louisiana's coastal ecosystem, infrastructure, and economy. On January 11-12, 2001, individuals from Federal and State agencies, universities, and the private sector met at the conference 'Coastal Marsh Dieback in the Northern Gulf of Mexico: Extent, Causes, Consequences, and Remedies' to discuss and share information shout the marsh dieback. Presentations discussed trends in the progress of dieback during the summer of 2000 and in environmental conditions occurring at field study sites, possible causes including drought and Mississippi low flow' conditions, changes in soil conditions (salinity, the bioavailability of metals, pathogens, etc.), the potential for wetland loss that could occur if above and below normality occurs and is sustained over an extended period, advanced techniques for tracking the dieback via aerial photography and remote sensing, linkages of marsh hydrology to the dieback, and mechanisms of modeling dieback and recovery. In addition, presentations were made regarding development of a web site to facilitate information sharing and progress in preparation for requests for proposals based on an emergency appropriation by the U.S. Congress. All findings tended to support the idea that the dieback constituted a continuing environmental emergency and research and natural resource management efforts should be expended accordingly.

  8. Coastal sensitivity mapping of Gulf of Kachchh and Gulf of Cambay, India

    Digital Repository Service at National Institute of Oceanography (India)

    ManiMurali, R.; Boora, P.; Vethamony, P.

    and managers of coastal zones are also useful for identifying sensitive resources before a spill occurs (Jenson, 1998). In this way, protection priorities could be identified and established and cleanup strategies could be designed in advance. To deal... by using different techniques of digital image processing. This study demonstrates the use of GIS approach to identify the area and resources that are likely to be affected due to an oil spill in the study area. Qualitative assessment of risk...

  9. Distribution of mercury in molluscs, seawaters and coastal sediments of Tarut Island, Arabian Gulf, Saudi Arabia

    Science.gov (United States)

    Youssef, Mohamed; El-Sorogy, Abdelbaset; Al-Kahtany, Khaled

    2016-12-01

    In order to assess the distribution of mercury along the Tarut coast, Arabian Gulf, Thirty eight (38) sediment samples, twenty six (26) seawater samples, and forty (40) Mollusca specimens were collected from the Tarut coast. The concentrations of Mercury in the sediments of the studied area (average = 0.55 μg/g) are generally high comparing to the reported values from the Gulf of Oman, Red Sea, and the Gulf of Finland. The concentrations of Hg exceeded the wet threshold safety values (median effect concentration (MEC), and probable effect concentration (PEC) indicating possible Hg contamination. According to the Swedish Environmental Protection Agency (SEPA), thirty four (34) samples occur in class 4 and four (4) samples occur in class 5, which means that the sediments of the Tarut Island are largely contaminated with Hg. Enrichment factor (EF) results (average = 1.76) suggested that, the coastal sediments of the Tarut Island are considered to entirely originate from the crustal materials or natural processes. The studied sediments show lower values (Igeo<0) indicating that the sediments are unpolluted. These sediments according to contamination factor (Cf) are considered contaminated with Hg (1 < CF < 3). The Hg concentration in water samples (average = 30 μg/g) considered high. Comparison with Hg contents in coastal sediments, seawaters and molluscs in the Red Sea, the Arabian Gulf suggested that the studied samples have higher concentrations of Hg. The suggested natural sources of Hg in the study area are the weathering and decomposition of neighboring deserts. The anthropogenic sources are the land reclamation, petrochemical industries, boat exhaust emissions, oil leakage, desalination plants and sewage effluents exceeded in the study area and in Al Jubail industrial city to the north.

  10. The Gulf of Mexico Coastal Ocean Observing System: A Decade of Data Aggregation and Services.

    Science.gov (United States)

    Howard, M.; Gayanilo, F.; Kobara, S.; Baum, S. K.; Currier, R. D.; Stoessel, M. M.

    2016-02-01

    The Gulf of Mexico Coastal Ocean Observing System Regional Association (GCOOS-RA) celebrated its 10-year anniversary in 2015. GCOOS-RA is one of 11 RAs organized under the NOAA-led U.S. Integrated Ocean Observing System (IOOS) Program Office to aggregate regional data and make these data publicly-available in preferred forms and formats via standards-based web services. Initial development of GCOOS focused on building elements of the IOOS Data Management and Communications Plan which is a framework for end-to-end interoperability. These elements included: data discovery, catalog, metadata, online-browse, data access and transport. Initial data types aggregated included near real-time physical oceanographic, marine meteorological and satellite data. Our focus in the middle of the past decade was on the production of basic products such as maps of current oceanographic conditions and quasi-static datasets such as bathymetry and climatologies. In the latter part of the decade we incorporated historical physical oceanographic datasets and historical coastal and offshore water quality data into our holdings and added our first biological dataset. We also developed web environments and products to support Citizen Scientists and stakeholder groups such as recreational boaters. Current efforts are directed towards applying data quality assurance (testing and flagging) to non-federal data, data archiving at national repositories, serving and visualizing numerical model output, providing data services for glider operators, and supporting marine biodiversity observing networks. GCOOS Data Management works closely with the Gulf of Mexico Research Initiative Information and Data Cooperative and various groups involved with Gulf Restoration. GCOOS-RA has influenced attitudes and behaviors associated with good data stewardship and data management practices across the Gulf and will to continue to do so into the next decade.

  11. Geoid determination in the coastal areas of the Gulf of Mexico

    Science.gov (United States)

    Song, HongZhi

    Coastal areas of the Gulf of Mexico are important for many reasons. This part of the United States provides vital coastal habitats for many marine species; the area has seen-ever increasing human settlement along the coast, ever increasing infrastructure for marine transportation of the nation's imports and exports through Gulf ports, and ever increasing recreational users of coastal resources. These important uses associated with the Gulf coast are subject to dynamic environmental and physical changes including: coastal erosion (Gulf-wide rates of 25 square miles per year), tropical storm surges, coastal subsidence, and global sea level rise. Coastal land subsidence is a major component of relative sea level rise along the coast of the Gulf of Mexico. These dynamic coastal changes should be evident in changes to the geoid along the coast. The geoid is the equipotential gravity surface of the earth, which the best fits the global mean sea level. The geoid is not only been seen as the most natural shape of the Earth, but also it serves as the reference surface for most of the height systems. By using satellites (GRACE mission) scientists have been able to measure the large scale geoid for the Earth. A small scale geoid model is required to monitor local events such as flooding, for example, flooding created by storm surges from hurricanes such as Katrina (2005), Rita (2005), and Ike (2008). The overall purpose of this study is to evaluate the accuracy of the local coastal geoid. The more precise geoid will enable to improve coastal flooding predictions, and will enable more cost effective and accurate measurement of coastal topography using global navigation satellite systems (GNSS). The main objective of this study is to devise mathematical models and computational methods to achieve the best possible precision for evaluation of the geoid in the coastal areas of the Gulf of Mexico. More specifically, the numerical objectives of this study are 1) to obtain a

  12. Distribution of dissolved inorganic carbon and related parameters in the Thermaikos Gulf (Eastern Mediterranean

    Directory of Open Access Journals (Sweden)

    E. KRASAKOPOULOU

    2012-12-01

    Full Text Available Data on the distribution of dissolved inorganic carbon (measured as TCO2 and related parameters in the Thermaikos Gulf were obtained during May 1997. High TCO2 concentrations were recorded close to the bottom, especially in the northern part of the gulf, as a result of organic matter remineralisation. The positive relatively good correlation between TCO2 and both apparent oxygen utilisation (AOU and phosphate at the last sampling depth confi rmed the regenerative origin of a large proportion of TCO2. The comparatively conservative behaviour of alkalinity, together with the relatively low value of the homogenous buffer factor β (β = ∂lnfCO2/∂lnTCO2 revealed that calcifi cation or carbonate dissolution takes place on a very small scale, simultaneously with the organic carbon production. The correlations between fCO2 and chlorophyll α, as well as AOU and the surface temperature, revealed that the carbon dioxide fi xation through the biological activity is the principal factor that modulates the variability of fCO2. A rough first estimate of the magnitude of the air-sea CO2 exchange and the potential role of the Thermaikos Gulf in the transfer of atmospheric CO2 was also obtained. The results showed that during May 1997, the Thermaikos Gulf acted as a weak sink for atmospheric CO2 at a rate of -0.60 - -1.43 mmol m-2 d-1, depending on which formula for the gas transfer velocity was used, and in accordance to recent reports regarding other temperate continental shelves. Extensive study of the dissolved inorganic carbon and related parameters, and continuous shipboard measurements of fCO2 a and fCO2 w during all seasons are necessary to safely quantify the role of the Thermaikos Gulf in the context of the coastal margins CO2 dynamics.

  13. Gulf Coast Deep Water Port Facilities Study. Appendix C. Eastern Gulf Hydrobiological Zones.

    Science.gov (United States)

    1973-04-01

    namely, activities regarding deep water ports including those for oil tankers). However, there are local populations, particularly in coastal zones...to eutrophication , pesticides. and petrochemical loads present in sediments. The Pensacola-Escamnbia-East BaY stsem has been gnrel ’re damaged. About...River 671 646.4 Palm River 62 45.2 Alatia River 384 418.2 Additional Area -92.6 Lower Tampa Bay 2.0- 2.3 Little Manatee River 186 205.2 Manatee River

  14. Shorebird use of coastal wetland and barrier island habitat in the Gulf of Mexico.

    Science.gov (United States)

    Withers, Kim

    2002-02-27

    The Gulf Coast contains some of the most important shorebird habitats in North America. This area encompasses a diverse mixture of estuarine and barrier island habitats with varying amounts of freshwater swamps and marshes, bottomland hardwood forests, and coastal prairie that has been largely altered for rice and crawfish production, temporary ponds, and river floodplain habitat. For the purposes of this review, discussion is confined to general patterns of shorebird abundance, distribution, and macro- and microhabitat use in natural coastal, estuarine, and barrier island habitats on the Gulf of Mexico Coast. The following geographic regions are considered: Northwestern Gulf (Rio Grande to Louisiana-Mississippi border), Northeastern Gulf (Mississippi to Florida Keys), and Mexico (Rio Grande to Cabo Catoche [Yucatan Strait]). Wintering and migrating shorebirds are most abundant along the Gulf Coast in Texas and Tamaulipas, particularly the Laguna Madre ecosystem. Other important areas are the Southwest Coast region of Florida and the area between Laguna Terminos and Puerto Progresso in Mexico. In general, relative abundances of shorebirds increase from north to south, and decrease south of the Tropic of Cancer (23 degrees 27' N). Based on bimonthly maximum counts within 5 latitudinal bands, the region between 25-30 degrees N is used most heavily by wintering and spring migrating birds. Non-vegetated coastal wetland habitats associated with bays, inlets and lagoons, particularly tidal flats, and sandy beaches are the habitats that appear to be favored by wintering and migrating shorebirds. In general, these habitats tend to occur as habitat complexes that allow for movement between them in relation to tidal flooding of bay-shore habitats. This relationship is particularly important to Piping Plover and may be important to others. Although vegetated habitats are used by some species, they do not appear to attract large numbers of birds. This habitat is most

  15. Organic carbon isotope ratios of recent sediments from coastal lagoons of the Gulf of Mexico, Mexico

    Science.gov (United States)

    Botello, Alfonso V.; Mandelli, Enrique F.; Macko, Steve; Parker, Patrick L.

    1980-03-01

    The stable carbon isotope composition sedimentary organic carbon was determined in the sediments of seven coastal lagoons of the Gulf of Mexico, Mexico. For most of the lagoons the δ13C values for sediments ranged from -20.1 to -23.9%. Anomalously low values, -26.8 to 29.3%. were determined in sediments of two of the studied lagoons, probably due to the presence of organic carbon from anthropogenic sources, naturally absent in these environments. The δ13C values determined in the tissues of oysters collected at the same time in the different lagoons were very similar to those recorded in the sediments.

  16. Hydrocarbons in coastal sediments from the Mediterranean sea (Gulf of Fos area, France).

    Science.gov (United States)

    Mille, Gilbert; Asia, Laurence; Guiliano, Michel; Malleret, Laure; Doumenq, Pierre

    2007-05-01

    Sedimentary hydrocarbons have been studied quantitatively and qualitatively in 11 coastal stations located in the Gulf of Fos (French Mediterranean coast). Hydrocarbon levels ranged from 10 to 260 mg kg(-1) sed. dry weight. A new parameter "NAR" (Natural n-alkane ratio) is proposed to evaluate the contribution of terrestrial inputs of hydrocarbons in the sediments. The origins of hydrocarbons are multiple: terrestrial inputs, biogenic, pyrolytic (industry emissions mainly steel and iron industries, ship and road traffic). Generally, the main source of contamination is not petroleum. Several ratios between parent polycyclic aromatic hydrocarbons show that the sources of hydrocarbons in the sediments are generally much more pyrolytic than petrogenic.

  17. Coastal Environmental Impacts Brought About by Alterations to Freshwater Flow in the Gulf of Mexico

    Science.gov (United States)

    Sklar; Browder

    1998-07-01

    / Freshwater inflow is one of the most influential landscape processes affecting community structure and function in lagoons, estuaries, and deltas of the world; nevertheless there are few reviews of coastal impacts associated with altered freshwater inputs. A conceptual model of the possible influences of freshwater inflows on biogeochemical and trophic interactions was used to structure this review, evaluate dominant effects, and discuss tools for coastal management. Studies in the Gulf of Mexico were used to exemplify problems commonly encountered by coastal zone managers and scientists around the world. Landscape alteration, impacting the timing and volume of freshwater inflow, was found to be the most common stress on estuarine systems. Poorly planned upstream landscape alterations can impact wetland and open-water salinity patterns, nutrients, sediment fertility, bottom topography, dissolved oxygen, and concentrations of xenobiotics. These, in turn, influence productivity, structure, and behavior of coastal plant and animal populations. Common biogeochemical impacts include excessive stratification, eutrophication, sediment deprivation, hypoxia, and contamination. Common biological impacts include reduction in livable habitats, promotion of "exotic" species, and decreased diversity. New multiobjective statistical models and dynamic landscape simulations, used to conduct policy-relevant experiments and integrate a wide variety of coastal data for freshwater inflow management, assume that optimum estuarine productivity and diversity is found somewhere between the stress associated with altered freshwater flow and the subsidy associated with natural flow. These models attempt to maximize the area of spatial overlap where favorable dynamic substrates, such as salinity, coincide with favorable fixed substrates, such as bottom topography. Based upon this principle of spatial overlap, a statistical performance model demonstrates how population vitality measurements

  18. Geothermal studies in oilfield districts of Eastern Margin of the Gulf of Suez, Egypt

    OpenAIRE

    Mohamed Abdel Zaher; Mohamed El Nuby; Essam Ghamry; Khamis Mansour; Nureddin M. Saadi; Heba Atef

    2014-01-01

    Results of geothermal studies carried out at 149 onshore oil wells have been used in evaluation of temperature gradient and heat flow values of the eastern shore of the Gulf of Suez. The investigations included temperature logs in boreholes, calculation of amplitude temperature, geothermal gradients and heat flow. The results obtained indicate that geothermal gradient values are in the ranges of 0.02–0.044 °C/m and regionally averaged mean heat flow values are found to fall in the interval of...

  19. Distribution of arsenic and mercury in subtropical coastal beachrock, Gulf of Mannar, India

    Indian Academy of Sciences (India)

    J Dajkumar Sahayam; N Chandrasekar; S Krishna Kumar; G Victor Rajamanickam

    2010-02-01

    An assessment of coastal pollution was made on the basis of trace element concentrations (arsenic –As, mercury – Hg) in the Gulf of Mannar. The beachrock samples were collected along the coastal tracts between Rameswaram and Kanyakumari. The samples were dried and digested to determine the As and Hg using atomic absorption spectrophotometer (AAS-air-acetylene and nitrous oxide method). The As and Hg accumulation status of the beachrock was assessed using geo-accumulation index values (). The accumulation of As and Hg in the beachrock ranges from 2.75 to 20.72 g g−1 and from 0.06 to 0.31 g g−1, respectively. The As and Hg concentrations in the beachrocks are compared with crustal average values and average of other region sediments. The possible source of the contamination is from atmospheric deposition and anthropogenic activities.

  20. Thermal response to the surface heat flux in a macrotidal coastal region (Nuevo Gulf, Argentina)

    Science.gov (United States)

    Rivas, Andrés L.; Pisoni, Juan P.; Dellatorre, Fernando G.

    2016-07-01

    At mid-latitudes, sea water temperature shows a strong seasonal cycle forced by the incident surface heat flux. As depth decreases, the heat flux incidence is damped by the horizontal flux, which prevents the indefinite growth of the seasonal temperature range. In the present work, cross-shore transport in the west coast of Nuevo Gulf (Argentina) was analyzed. Processes tending to cool the coastal waters in summer and to warm the coastal waters in winter, were identified through temperature measurements, surface heat flux and tidal height. The simplified models proposed here provide a feedback mechanism that links changes in surface heat flux with changes in the horizontal heat flux during both seasons. On shorter time scales, tide produces significant variations in the height of the water column, therefore influencing temperature fluctuations and the direction of the horizontal flow.

  1. National assessment of hurricane-induced coastal erosion hazards--Gulf of Mexico

    Science.gov (United States)

    Stockdon, Hilary F.; Doran, Kara S.; Thompson, David M.; Sopkin, Kristin L.; Plant, Nathaniel G.; Sallenger, Asbury H.

    2012-01-01

    Sandy beaches provide a natural barrier between the ocean and inland communities, ecosystems, and resources. However, these dynamic environments move and change in response to winds, waves, and currents. During a hurricane, these changes can be large and sometimes catastrophic. High waves and storm surge act together to erode beaches and inundate low-lying lands, putting inland communities at risk. A decade of USGS research on storm-driven coastal change hazards has provided the data and modeling capabilities to identify areas of our coastline that are likely to experience extreme and potentially hazardous erosion during a hurricane. This report defines hurricane-induced coastal erosion hazards for sandy beaches along the U.S. Gulf of Mexico coastline. The analysis is based on a storm-impact scaling model that uses observations of beach morphology combined with sophisticated hydrodynamic models to predict how the coast will respond to the direct landfall of category 1-5 hurricanes. Hurricane-induced water levels, due to both surge and waves, are compared to beach and dune elevations to determine the probabilities of three types of coastal change: collision (dune erosion), overwash, and inundation. As new beach morphology observations and storm predictions become available, this analysis will be updated to describe how coastal vulnerability to storms will vary in the future.

  2. Geothermal studies in oilfield districts of Eastern Margin of the Gulf of Suez, Egypt

    Directory of Open Access Journals (Sweden)

    Mohamed Abdel Zaher

    2014-06-01

    Full Text Available Results of geothermal studies carried out at 149 onshore oil wells have been used in evaluation of temperature gradient and heat flow values of the eastern shore of the Gulf of Suez. The investigations included temperature logs in boreholes, calculation of amplitude temperature, geothermal gradients and heat flow. The results obtained indicate that geothermal gradient values are in the ranges of 0.02–0.044 °C/m and regionally averaged mean heat flow values are found to fall in the interval of 45–120 mW/m2. Temperature gradients and heat flow values change from low values eastward to high values toward the axial of Gulf of Suez rift. The result of this research work has been highly successful in identifying new geothermal resources eastward of the Gulf of Suez. Additionally, this study shows that the areas with relatively higher temperature gradients have lower oil window, mature earlier, than those with low gradient values. Thus, high temperature gradients cause to expedite the formation of oil at relatively shallow depths and narrow oil windows. On the other hand, low temperature gradient makes the oil window to be quite broad when locate at high depths.

  3. Assessment of coastal flood risk in a changing climate along the northern Gulf of Mexico

    Science.gov (United States)

    Bilskie, M. V.; Hagen, S. C.; Passeri, D. L.; Alizad, K.

    2014-12-01

    Coastal regions around the world are susceptible to a variety of natural disasters causing extreme inundation. It is anticipated that the vulnerability of coastal cities will increase due to the effects of climate change, and in particular sea level rise (SLR). We have developed a novel framework to construct a physics-based storm surge model that includes projections of coastal floodplain dynamics under climate change scenarios. Numerous experiments were conducted and it was concluded that a number of influencing factors, other than SLR, should be included in future assessments of coastal flooding under climate change; e.g., shoreline changes, barrier island morphology, salt marsh migration, and population dynamics. These factors can significantly affect the path, pattern, and magnitude of flooding depths and inundation along the coastline (Bilskie et al., 2014; Passeri et al., 2014). Using these factors, a storm surge model of the northern Gulf of Mexico (NGOM) representing present day conditions is modified to characterize the future outlook of the landscape. This adapted model is then used to assess flood risk in terms of the 100-year floodplain surface under SLR scenarios. A suite of hundreds of synthetic storms, derived by JPM-OS (Joint Probability Method - Optimum Sampling), are filtered to obtain the storms necessary to represent the statistically determined 100-year floodplain. The NGOM storm surge model is applied to simulate the synthetic storms and determine, for each storm, the flooding surface and depth, for four SLR scenarios for the year 2100 as prescribed by Parris et al. (2012). The collection of results facilitate the estimation of water surface elevation vs. frequency curves across the floodplain and the statistically defined 100-year floodplain is extracted. This novel method to assess coastal flooding under climate change can be performed across any coastal region worldwide, and results provide awareness of regions vulnerable to extreme

  4. A paleomagnetic investigation of vertical-axis rotations in coastal Sonora, Mexico: Evidence for distributed transtensional deformation during the Proto-Gulf shift from a subduction-dominated to transform-dominated plate boundary in the Gulf of California

    Science.gov (United States)

    Herman, Scott William

    The history of late Miocene (Proto-Gulf) deformation on the Sonoran margin of the Gulf of California is key to understanding how Baja California was captured by the Pacific plate and how strain was partitioned during the Proto-Gulf period (12.5-6 Ma). The Sierra el Aguaje and Sierra Tinajas del Carmen are located in southwestern coastal Sonora, Mexico, and represent the eastern rifted margin of the central Gulf of California. The ranges are composed of volcanic units and their corresponding volcaniclastic units which are the result of persistent magmatic activity between 20 and 8.8 Ma, including three packages of basalt and andesite that make excellent paleomagnetic recorders. Based on cross cutting relations and geochronologic data for pre-, syn-, and post-tectonic volcanic units, most of the faulting and tilting in the Sierra El Aguaje is bracketed between 11.9 and 9.0 Ma, thus falling entirely within Proto-Gulf time. A paleomagnetic investigation into possible vertical axis rotations in the Sierra el Aguaje has uncovered evidence of clockwise rotations between ~13º and ~105º with possible translations. These results are consistent with existing field relations, which suggest the presence of large (>45°) vertical axis rotations in this region. This evidence includes: a) abrupt changes in the strike of tilted strata in different parts of the range, including large domains characterized by E-W strikes b) ubiquitous NE-SW striking faults with left lateral-normal oblique slip, that terminate against major NW-trending right lateral faults, and c) obliquity between the general strike of tilted strata and the strike of faults. These rotations occurred after 12 Ma and largely prior to 9 Ma, thus falling into the Proto-Gulf period. Such large-scale rotations lend credence to the theory that the area inboard of Baja California was experiencing transtension during the Proto-Gulf period, rather than the pure extension that would be the result of strain partitioning

  5. Oil pollution and the carbon isotope ratio in organisms and Recent sediments of coastal lagoons in the Gulf of Mexico

    OpenAIRE

    Botello, A V; Macko, Sa

    1982-01-01

    Samples of recent sediments and marine organisms from seven coastal lagoons along the Mexican coast of the Gulf of Mexico were analyzed by gas chromatography and GC-MS coupled system to determine the present levels of fossil hydrocarbons. Results show that the highest concentrations of fossil hydrocarbons are present in organisms and sediments located near petrochemical plants and oil refineries, indicating that petroleum hydrocarbons are being released into the coastal lagoons. Stable carbon...

  6. Effects of Climate Change on Freshwater Ecosystems of the South-Eastern United States and the Gulf Coast of Mexico

    Science.gov (United States)

    Mulholland, Patrick J.; Best, G. Ronnie; Coutant, Charles C.; Hornberger, George M.; Meyer, Judy L.; Robinson, Peter J.; Stenberg, John R.; Turner, R. Eugene; Vera-Herrera, Francisco; Wetzel, Robert G.

    1997-06-01

    The south-eastern United States and Gulf Coast of Mexico is physiographically diverse, although dominated by a broad coastal plain. Much of the region has a humid, warm temperate climate with little seasonality in precipitation but strong seasonality in runoff owing to high rates of summer evapotranspiration. The climate of southern Florida and eastern Mexico is subtropical with a distinct summer wet season and winter dry season. Regional climate models suggest that climate change resulting from a doubling of the pre-industrial levels of atmospheric CO2 may increase annual air temperatures by 3-4°C. Changes in precipitation are highly uncertain, but the most probable scenario shows higher levels over all but the northern, interior portions of the region, with increases primarily occurring in summer and occurring as more intense or clustered storms. Despite the increases in precipitation, runoff is likely to decline over much of the region owing to increases in evapotranspiration exceeding increases in precipitation. Only in Florida and the Gulf Coast areas of the US and Mexico are precipitation increases likely to exceed evapotranspiration increases, producing an increase in runoff. However, increases in storm intensity and clustering are likely to result in more extreme hydrographs, with larger peaks in flow but lower baseflows and longer periods of drought.The ecological effects of climate change on freshwaters of the region include: (1) a general increase in rates of primary production, organic matter decomposition and nutrient cycling as a result of higher temperatures and longer growing seasons: (2) reduction in habitat for cool water species, particularly fish and macroinvertebrates in Appalachian streams; (3) reduction in water quality and in suitable habitat in summer owing to lower baseflows and intensification of the temperature-dissolved oxygen squeeze in many rivers and reservoirs; (4) reduction in organic matter storage and loss of organisms during

  7. Effects of climate change on freshwater ecosystems of the south-eastern United States and the Gulf Coast of Mexico

    Science.gov (United States)

    Mulholland, P.J.; Best, G.R.; Coutant, C.C.; Hornberger, G.M.; Meyer, J.L.; Robinson, P.J.; Stenberg, J.R.; Turner, R.E.; Vera-Herrera, F.; Wetzel, R.G.

    1997-01-01

    The south-eastern United States and Gulf Coast of Mexico is physiographically diverse, although dominated by a broad coastal plain. Much of the region has a humid, warm temperate climate with little seasonality in precipitation but strong seasonality in runoff owing to high rates of summer evapotranspiration. The climate of southern Florida and eastern Mexico is subtropical with a distinct summer wet season and winter dry season. Regional climate models suggest that climate change resulting from a doubling of the pre-industrial levels of atmospheric CO2 may increase annual air temperatures by 3-4??C. Changes in precipitation are highly uncertain, but the most probable scenario shows higher levels over all but the northern, interior portions of the region, with increases primarily occurring in summer and occurring as more intense or clustered storms. Despite the increases in precipitation, runoff is likely to decline over much of the region owing to increases in evapotranspiration exceeding increases in precipitation. Only in Florida and the Gulf Coast areas of the US and Mexico are precipitation increases likely to exceed evapotranspiration increases, producing an increase in runoff. However, increases in storm intensity and clustering are likely to result in more extreme hydrographs, with larger peaks in flow but lower baseflows and longer periods of drought. The ecological effects of climate change on freshwaters of the region include: (1) a general increase in rates of primary production, organic matter decomposition and nutrient cycling as a result of higher temperatures and longer growing seasons: (2) reduction in habitat for cool water species, particularly fish and macroinvertebrates in Appalachian streams; (3) reduction in water quality and in suitable habitat in summer owing to lower baseflows and intensification of the temperature-dissolved oxygen squeeze in many rivers and reservoirs; (4) reduction in organic matter storage and loss of organisms during

  8. Aerosol optical thickness and spatial variability along coastal and offshore waters of the eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Menon, H.B.; Sangekar, N.; Lotliker, A.; Moorthy, K.K.; Vethamony, P.

    quantity required for determining aerosol radiative forcing at the top of the atmosphere. The role of aerosols in climate change remains uncertain. Although the theory behind their effect on outgoing terrestrial and incoming solar radiations is well... waters. The current study aims to formulate a technique to derive AOT from OCM 3 over coastal waters and to demonstrate the method’s potential for analysing aerosol distribution along the eastern coastal Arabian Sea. In the fisheries context, these AOT...

  9. Relationships Between Bird Communities and Forest Age, Structure, Species Composition and Fragmentation in the West Gulf Coastal Plain

    Science.gov (United States)

    Richard N. Conner; James G. Dickson

    1997-01-01

    Bird communities of the West Gulf Coastal Plain are strongly influenced by the stage of forest succession, species composition of understory and overstory vegetation, and forest structure. Alteration of plant communities through forest management and natural disturbances typically does not eliminate birds as a fauna1 group from the area affected, but will replace some...

  10. Application of a three-tier framework to assess ecological condition of Gulf of Mexico coastal wetlands

    Science.gov (United States)

    A multi‐level coastal wetland assessment strategy was applied to wetlands in the northern Gulf of Mexico (GOM) to evaluate the feasibility of this approach for a broad national scale wetland condition assessment (U.S. Environmental Protection Agency’s National Wetlands Condition ...

  11. United States Gulf of Mexico Coastal Marsh Vegetation Responses and Sensitivities to Oil Spill: A Review

    Directory of Open Access Journals (Sweden)

    S. Reza Pezeshki

    2015-12-01

    Full Text Available The present review summarizes the literature on the effects of oil spill on the U.S. Gulf of Mexico coastal vegetation including freshwater-, brackish-, and salt-marshes. When in contact with plant tissues, oil may have adverse impacts via physical and chemical effects. Oil may also become detrimental to plants by covering soil surfaces, leading to root oxygen stress and/or penetrate into the soil where it becomes in contact with the roots. The affected vegetation may survive the impact by producing new leaves, however, an episode of oil spill may impose severe stress. Oil spills may lead to partial or complete plant death but in many situations plants recover by regenerating new shoots. Plant sensitivity to oil varies among species; plants from salt marshes appear to be more sensitive than freshwater species. In addition, sensitivity appears to be dependent on the oil characteristics and the quantity of oil being spilled, repeated oiling events, season of spill, greenhouse vs. field conditions, and plant age are among the many factors that interact simultaneously. Many aspects of coastal plant responses to oiling remain in need of additional research, including the possibility that differences in oil sensitivity may interact with changes in the environment, and contribution to additional wetland losses through coastal erosion. Environmental stressors such as drought and salinity may also interact with oil, leading to the observed changes in plant species community composition following an oil spill.

  12. Deciphering the forcing factors of coastal evolution from a numerical chronology for a coastal sediment succession, Eastern Hengchun Peninsula, Taiwan

    Science.gov (United States)

    Lüthgens, Christopher; Ho, Lih-Der; Jen, Chia-Hung; Chyi, Shyh-Jeng

    2016-04-01

    Taiwan, an island with a high mountain area attaining almost 4000 m, is located in a unique position in East Asia at the transition from the subtropical to the tropical zone. The climate is driven by the East-Asian monsoon, which is responsible for a humid climate during the whole year. In addition, earthquakes, tropical storms, and typhoons trigger morphodynamic processes. Taiwan's coastal landscape is the result of complex interactions between marine and subaerial processes, sediment supply and local geology, plate tectonics, climate change, and global sea-level fluctuations. Unconsolidated sediments in coastal areas are known to preserve valuable information about these processes driving the coastal landscape evolution. In the Ganko river basin, located on the Eastern Hengchun peninsula in south-eastern Taiwan, climatic and tectonic forcing factors may have significantly influenced the natural sediment yield and sediment storage over time. In addition, in the recent past human influence within the river catchment may significantly have altered the sediment yield in the coastal areas close to the rivermouth. In order to reconstruct such variations and ideally relate them to either tectonic, climatic and anthropogenic forcing, a detailed analysis of sedimentary archives is essential. The area under investigation comprises a complex terrestrial river terrace record as well as a coastal sediment succession at the river outlet, both in parts aggraded above presumably tectonically uplifted near-shore sediments. Establishing a high resolution numerical chronology for these sediments may allow a reconstruction of sediment aggradation phases and stability phases for different sections of the catchment area from upstream fluvial terraces to coastal deposits, as well as the underlying near-shore deposits. A combination of two independent dating methods, optically stimulated luminescence (OSL) dating using the pIRIR150 signal of feldspar, as well as radiocarbon dating, was

  13. Characterisation of coastal counter-currents on the inner shelf of the Gulf of Cadiz

    Science.gov (United States)

    Garel, E.; Laiz, I.; Drago, T.; Relvas, P.

    2016-03-01

    At the Gulf of Cadiz (GoC), poleward currents leaning along the coast alternate with coastal upwelling jets of opposite direction. Here the patterns of these coastal countercurrents (CCCs) are derived from ADCP data collected during 7 deployments at a single location on the inner shelf. The multiyear (2008-2014) time-series, constituting ~ 18 months of hourly records, are further analysed together with wind data from several sources representing local and basin-scale conditions. During one deployment, temperature sensors were also installed near the mooring site to examine the vertical thermal stratification associated with periods of poleward flow. These observations indicate that the coastal circulation is mainly alongshore and barotropic. However, a baroclinic flow is often observed shortly at the time of flow inversion to poleward. CCCs develop all year-round and exclusively control the occurrence of warm coastal water during the upwelling season. On average, one poleward flow lasting 3 days was observed every week, corresponding to CCCs during ~ 40% of the time without seasonal variability. Thus, the studied region is distinct from typical upwelling systems where equatorward coastal upwelling jets largely predominate. CCCs often start to develop near the bed and are frequently associated with 2-layer cross-shore flows characteristic of downwelling conditions (offshore near the bed). In general, the action of alongshore wind stress alone does not justify the development of CCCs. The coastal circulation is best correlated and shows the highest coherence with south-eastward wind in the basin that proceeds from the rotation of southward wind at the West coast of Portugal, hence suggesting a dominant control of large-scale wind conditions. In agreement, wavelet analyses indicate that CCCs are best correlated with alongshore wind occurring in a band period characteristic of the upwelling system (8-32 days). Furthermore, in the absence of wind coastal currents tend

  14. Comparative Analysis of Sea Surface Temperature Pattern in the Eastern and Western Gulfs of Arabian Sea and the Red Sea in Recent Past Using Satellite Data

    Directory of Open Access Journals (Sweden)

    Neha Nandkeolyar

    2013-01-01

    Full Text Available With unprecedented rate of development in the countries surrounding the gulfs of the Arabian Sea, there has been a rapid warming of these gulfs. In this regard, using Advanced Very High Resolution Radiometer (AVHRR data from 1985 to 2009, a climatological study of Sea Surface Temperature (SST and its inter annual variability in the Persian Gulf (PG, Gulf of Oman (GO, Gulf of Aden (GA, Gulf of Kutch (KTCH, Gulf of Khambhat (KMBT, and Red Sea (RS was carried out using the normalized SST anomaly index. KTCH, KMBT, and GA pursued the typical Arabian Sea basin bimodal SST pattern, whereas PG, GO, and RS followed unimodal SST curve. In the western gulfs and RS, from 1985 to 1991-1992, cooling was observed followed by rapid warming phase from 1993 onwards, whereas in the eastern gulfs, the phase of sharp rise of SST was observed from 1995 onwards. Strong influence of the El Niño and La Niña and the Indian Ocean Dipole on interannual variability of SST of gulfs was observed. Annual and seasonal increase of SST was lower in the eastern gulfs than the western gulfs. RS showed the highest annual increase of normalized SST anomaly (+0.64/decade followed by PG (+0.4/decade.

  15. Potential for deep basin-centered gas accumulation in Travis Peak (Hosston) Formation, Gulf Coastal Basin

    Science.gov (United States)

    Bartberger, Charles E.; Dyman, Thaddeus S.; Condon, Steven M.

    2003-01-01

    The potential of Lower Cretaceous sandstones of the Travis Peak Formation in the northern Gulf Coast Basin to harbor a basin-centered gas accumulation was evaluated by examining (1) the depositional and diagenetic history and reservoir properties of Travis Peak sandstones, (2) the presence and quality of source rocks for generating gas, (3) the burial and thermal history of source rocks and time of gas generation and migration relative to tectonic development of Travis Peak traps, (4) gas and water recoveries from drill-stem and formation tests, (5) the distribution of abnormal pressures based on shut-in-pressure data, and (6) the presence or absence of gas-water contacts associated with gas accumulations in Travis Peak sandstones. The Travis Peak Formation (and correlative Hosston Formation) is a basinward-thickening wedge of terrigenous clastic sedimentary rocks that underlies the northern Gulf Coast Basin from eastern Texas across northern Louisiana to southern Mississippi. Clastic infl ux was focused in two main fl uvial-deltaic depocenters?one located in northeastern Texas and the other in southeastern Mississippi and northeastern Louisiana. Across the main hydrocarbon-productive trend in eastern Texas and northern Louisiana, the Travis Peak Formation is about 2,000 ft thick. Most Travis Peak hydrocarbon production in eastern Texas comes from drilling depths between 6,000 and 10,000 ft. Signifi cant decrease in porosity and permeability occurs through that depth interval. Above 8,000-ft drilling depth in eastern Texas, Travis Peak sandstone matrix permeabilities often are signifi cantly higher than the 0.1-millidarcy (mD) cutoff that characterizes tight-gas reservoirs. Below 8,000 ft, matrix permeability of Travis Peak sandstones is low because of pervasive quartz cementation, but abundant natural fractures impart signifi cant fracture permeability. Although pressure data within the middle and lower Travis Peak Formation are limited in eastern Texas

  16. Coccolithophore diversity and dynamics at a coastal site in the Gulf of Trieste (northern Adriatic Sea)

    Science.gov (United States)

    Cerino, Federica; Malinverno, Elisa; Fornasaro, Daniela; Kralj, Martina; Cabrini, Marina

    2017-09-01

    Two years-data (May 2011-February 2013) obtained from a monthly sampling carried out at the coastal long term Ecological Research station C1-LTER in the Gulf of Trieste (northern Adriatic Sea) were analysed to describe the seasonal dynamics and diversity of coccolithophore assemblages and to assess their relationship with environmental forcing. Coccolithophores represented 10.7% of the total Utermöhl phytoplankton that were mainly dominated by small (Statistical analyses recognized four distinct groups, corresponding to seasonal variations of environmental conditions. Considering the two years, some species displayed a recurrent seasonal pattern highlighting possible species-specific ecological requirements, while others showed an interannual variability probably due to local factors.

  17. Spatial distribution and abundance of the megabenthic fauna community in Gabes gulf (Tunisia, eastern Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    H. EL LAKHRACH

    2012-12-01

    Full Text Available The aim of this paper is to bring to light the knowledge of marine diversity of invertebrates in Gabes gulf. The spatial distribution of the megabenthic fauna community in Gabes gulf (Tunisia, Eastern Mediterranean Sea, together with the bottom type and vegetation cover, were studied. The abundance of the megabenthic fauna was represented by eight groups: Echinodermata (38%, Crustacea (21%, Tunicata (19%, Mollusca (13%, Porifera (4%, Cnidaria (3%, Bryozoa, and Annelida (2%. It was spatially more concentrated in the coast area of the gulf than in the offshore waters. This area, especially, in Southern Kerkennah, North-est of Gabes and North-east of Djerba appeared to be in a good ecological condition  hosting a variety of species like the paguridsPaguristes eremita and Pagurus cuanensis, the brachyura Medorippe lanata, Inachus doresttensis, the Gastropoda Hexaplex trunculus, Bolinus brandaris, Aporrhais pespelecani, andErosaria turdus, the Bivalvia Fulvia fragilis, the Echinoidea Psammechinus microtuberculatus, Holothuria polii,Ophiothrix fragilis and Antedon mediterranea, and the AscidiaceaAplidium cf. conicum, Didemnum spp, and Microcosmus exasperatus.The species’ compositions of the megabentic fauna community showed clearly that the spatial analysis represented the differences between the community of these two regions (inshore waters and offshore waters. These differences were closely related to peculiar characters of the fauna and biotopes (depth, bottom type and vegetation cover community. The results of the present study should be considered as a necessary starting point for a further analysis of priceless benthic fauna contribution to the marine environment and its organisms.

  18. Refraction studies between Icy Bay and Kayak Island, eastern Gulf of Alaska

    Science.gov (United States)

    Bayer, K.C.; Mattick, R.E.; Bruns, T.R.; Plafker, George

    1978-01-01

    Results of five seismic refraction lines shot by the U.S. Geological Survey in the Gulf of Alaska between Icy Bay and Kayak Island indicate the following: (1) The Continental Shelf is underlain by as much as 11 km of sedimentary rock of probable Tertiary age where refraction velocities range from 1.2 to 5.5 kilometers per second; (2) a section approximately 5 km thick, which has velocities of 4.1-5.5 km/s and which could represent the Orca Group (lower Tertiary), is present in the western part of the study area but not in the eastern part; and (3) consistent basement velocities of approximately 7.0 km/s could indicate oceanic crust underlying the continental margin.

  19. Association of Colloidal Organic Matter and Metals in Coastal Waters (Gulf of Trieste, Northern Adriatic Sea)

    Science.gov (United States)

    Faganeli, J.; Klun, K.; Falnoga, I.; Mazej, D.; Kovač, N.

    2016-12-01

    Large volumes of seawater were sampled in the Gulf of Trieste (northern Adriatic Sea) in order to study the seasonal changes of interactions between colloidal organic matter (COM) and metals/metalloids (Me) in coastal waters. Isolation of COM (>5 kDa) was performed by ultrafiltration and final desalinization by dialysis. COM was characterized using 1H NMR and FTIR spectroscopy, and C and N elemental, and 13C and 15N isotope analyses. COM represents about 1/4 of DOC and appears to be mainly of marine origin. COM is composed of polysaccharides (30-45%), lipids (30-55%), proteins (15-20%) and humics (OH (carbohydrates and lipids), COOH (proteins and lipids) and NH (proteins) functional groups. In the late spring - early summer, an accumulation of COM was observed, demostrated by HPSEC, indicating the possible path of macroaggregate formation. The polysaccharide and lipid fractions increased and the protein fraction decreased. COM isolated from phytoplankton cultures (Tetraselmis marina, Chaetoceros socialis, Prorocentrum minimum) from the gulf indicated that phytoplankton mostly contributes to the polysaccharide COM pool. Analyses of Me, performed by ICPMS and CVAFS (Hg), showed that Hg (>90%), V (35%), Cu (20%), Cr (10%) and Se (10%) have the highest Me affinity to COM. Similarly to COM, Hg and Cu rapidly decreased in summer due to their sequestration in aggregates (transfer into particulate phase) and increased microbial degradation. The observed Me/Corg. ratios (Co, Cd, Hg, < U, Cr, Ni, Mn < As, Zn, Cu, V < Fe) somewhat differ from those of Irving-Williams series and can be explained by composition of COM and variable background concentrations of studied Me. Data from the salinity gradient in the gulf showed flocculation of Al and Cu and desorption of V, Mn, As, Se, Rb, Sr, Ag, Cd, Cs, Tl, U and Hg from the riverine particles with increasing ionic strength while Fe, Cr, Ni, Zn and Pb did not correlate with salinity.

  20. Assessment of natural radioactivity and (137)Cs in some coastal areas of the Saudi Arabian gulf.

    Science.gov (United States)

    Al-Ghamdi, H; Al-Muqrin, A; El-Sharkawy, A

    2016-03-15

    The levels of natural radioactivity have been investigated in some Saudi Arabian Gulf coastal areas. Sampling sites were chosen according to the presence of nearby non-nuclear industrial activities such as, the two main water desalination plants in Al Khobar and Al Jubail, and Maaden phosphate complex in Ras Al Khair, to ensure that effluents discharges into the Arabian Gulf didn't enhance radioactivity in seawater and shore sediments. Seawater samples were analyzed for radium isotopes (Ra-226 & Ra-228) and measured by gamma spectrometry using high purity germanium detector, after radiochemical separation of the isotopes by co-precipitation with MnO2. Shore sediment samples were analyzed for (226)Ra, (228)Ra ((232)Th), (4)°K and (137)Cs using gamma sepectrometry. A small variation was observed in the activity concentrations of the investigated radioisotopes, and the activity levels were comparable to those reported in literature. Quality assurance and methods validation were established through the efficiency calibration of the detectors, the estimation of uncertainties, the use of blanks, the analysis of standard reference materials and the intercomparison and proficiency tests. Radiological hazards were assessed, and the annual effective dose had an average value of 0.02 mSv. On the basis of the current results, we may conclude that any radiological hazards to the public visiting these shores are not expected.

  1. Species Profiles: Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (Gulf of Mexico), Red Snapper

    Science.gov (United States)

    1988-08-01

    I-F and Invertebrates (Gulf of Mexico) OT0418 0 RED SNAPPER DsTRIBTION 5TATF~ vENTA Df ’iubuo- I Coastal Ecology Group Fish and Wildlife Service W...binder is used for this series so that new profiles can be added as they are prepared. This project is jointly planned and financed by the U.S. Army...management logy of the red snapper, Lutjanus plan for the reef fish fishery of campechanus (Poey), from three areas the Gulf of mexico. Pages 1-1 to aong the

  2. Long-term Bat Monitoring on Islands, Offshore Structures, and Coastal Sites in the Gulf of Maine, mid-Atlantic, and Great Lakes—Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, Trevor [Stantec Consulting Services Inc., Topsham, ME (United States); Pelletier, Steve [Stantec Consulting Services Inc., Topsham, ME (United States); Giovanni, Matt [Stantec Consulting Services Inc., Topsham, ME (United States)

    2016-01-15

    This report summarizes results of a long-term regional acoustic survey of bat activity at remote islands, offshore structures, and coastal sites in the Gulf of Maine, Great Lakes, and mid-Atlantic coast.

  3. Coastal circulation off southern Tamaulipas and northern Veracruz, western Gulf of Mexico, during winter 2012-2013

    Science.gov (United States)

    Rivas, David

    2015-04-01

    Four months of observations from a near-coastal mooring deployed off southern Tamaulipas-northern Veracruz coast (western Gulf of Mexico) during winter 2012-2013 provides velocity, temperature, and salinity series in a region where apparently no in-situ measurements have been formally reported. The measurements show numerous events of intense alongshore velocities with magnitudes typically exceeding 80 cm/s, associated with intensified winds associated with the cold fronts invading the western Gulf during fall-winter, via coastal-trapped motions coming from northern locations. These motions must induce a coastal jet that modulates the regional along-shelf transports. This notion is corroborated by an analytical coastal-trapped wave (CTW) model which explains most of the variability of the sea level and the alongshore barotropic velocity observed in the mooring. Several near-inertial signals exceeding 50 cm/s are also observed at the surface levels. These high-frequency (HF) signals occur several hours before the intensified currents induced by the winds. Comparison between HF series of water velocity and wind suggests a direct influence of the winds affecting the NW Gulf (northern Tamaulipas/southern Texas) about 6-9 hours before the occurrence of the HF currents at the mooring. These near-inertial events induce a vigorous mixing of the local riverine discharge.

  4. National assessment of hurricane-induced coastal erosion hazards—Gulf of Mexico update

    Science.gov (United States)

    Doran, Kara; Stockdon, Hilary F.; Thompson, David M.; Birchler, Justin; Plant, Nathaniel G.; Overbeck, Jacquelyn R.

    2016-01-01

    These data sets contain information on the probabilities of hurricane-induced erosion (collision, inundation and overwash) for each 1-km section of the Gulf of Mexico coast for category 1-5 hurricanes. The analysis is based on a storm-impact scaling model that uses observations of beach morphology combined with sophisticated hydrodynamic models to predict how the coast will respond to the direct landfall of category 1-5 hurricanes. Hurricane-induced water levels, due to both surge and waves, are compared to beach and dune elevations to determine the probabilities of three types of coastal change: collision (dune erosion), overwash, and inundation. Data on dune morphology (dune crest and toe elevation) and hydrodynamics (storm surge, wave setup and runup) are also included in this data set. As new beach morphology observations and storm predictions become available, this analysis will be updated to describe how coastal vulnerability to storms will vary in the future. The data presented here include the dune morphology observations, as derived from lidar surveys. For further information regarding data collection and/or processing methods refer to USGS Open-File Report 2012–1084 (http://pubs.usgs.gov/of/2012/1084/).

  5. Comprehensive and comparative ecotoxicological and human risk assessment of polycyclic aromatic hydrocarbons (PAHs) in reef surface sediments and coastal seawaters of Iranian Coral Islands, Persian Gulf.

    Science.gov (United States)

    Ranjbar Jafarabadi, Ali; Riyahi Bakhtiari, Alireza; Shadmehri Toosi, Amirhossein

    2017-11-01

    The concentration and spatial distribution along with ecotoxicological risk of 30 polycyclic aromatic hydrocarbons were investigated in the reef surface sediments (RSSs) and coastal seawater (CSW) of ten coral Islands from the Persian Gulf, Iran, in January 2015. For all sampling sites, assessment of ecological risk was undertaken using several approaches. Mean concentration of ∑30PAHs varied between 70 and 884ngL(-l) with an overall mean value of 464ngL(-l) in the CSW, while the RSS ranged from 274 to 1098ngg(-1)dw with a total average of 619ngg(-1)dw. The results showed a gradient in PAH concentration and toxicity estimates from the northern Hormoz site increasing to the eastern Kharg site. Most of the toxicity estimates were in the moderate range or less than risk values for damage to the marine environment. The calculated Dermal Hazard Quotient (HQs), the sum of HQs (HI) and other cancer risk values of most compounds were less than safety values at most sites. It means that the possibility of negative effects of PAHs via dermal absorption from sediments for children and adults is low. Some sampling sites studied have already been impacted with hazardous pollutants for an extended period of time and evidence from this investigation demonstrates that mixtures of PAHs may be carcinogenic to humans, especially in the western part of the Gulf. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. NOAA Office for Coastal Management Coastal Inundation Digital Elevation Model: Virginia, Eastern Shore

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data were created as part of the National Oceanic and Atmospheric Administration Office for Coastal Management's efforts to create an online mapping viewer...

  7. Assessment of arsenic in coastal sediments, seawaters and molluscs in the Tarut Island, Arabian Gulf, Saudi Arabia

    Science.gov (United States)

    El-Sorogy, Abdelbaset S.; Youssef, Mohamed; Al-Kahtany, Khaled; Al-Otaiby, Naif

    2016-01-01

    In order to assess arsenic on the Tarut coast, Saudi Arabian Gulf, 38 sediment samples, 26 seawater samples and 40 gastropod and bivalve specimens were collected for analyses by Inductively Coupled Plasma-Mass Spectrometer. The Enrichment Factor (EF), the Geoaccumulation Index (Igeo) and the Contamination Factor (CF) indicated that coastal sediments of Tarut Island are severely enriched, strongly polluted and very highly contaminated with arsenic as a result of anthropogenic inputs. Comparison with arsenic in coastal sediments, seawaters and molluscs in the Red Sea, the Arabian Gulf and abroad coasts suggested that the studied samples have higher concentrations of As. The suggested natural sources of arsenic in the study area are the weathering and decomposition of neighboring deserts. The anthropogenic sources include the land reclamation, petrochemical industries, boat exhaust emissions, oil leakage, desalination plants and sewage effluents. These anthropogenic sources are the dominant sources of As in the study area and mostly came from Al Jubail industrial city to the north.

  8. Summary of Training Workshop on the Use of NASA tools for Coastal Resource Management in the Gulf of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Judd, Chaeli; Judd, Kathleen S.; Gulbransen, Thomas C.; Thom, Ronald M.

    2009-03-01

    A two-day training workshop was held in Xalapa, Mexico from March 10-11 2009 with the goal of training end users from the southern Gulf of Mexico states of Campeche and Veracruz in the use of tools to support coastal resource management decision-making. The workshop was held at the computer laboratory of the Institute de Ecologia, A.C. (INECOL). This report summarizes the results of that workshop and is a deliverable to our NASA client.

  9. Dispersion and retrievability of water quality indicators during tidal cycles in coastal Salaya, Gulf of Kachchh (West coast of India)

    Digital Repository Service at National Institute of Oceanography (India)

    Mohandass, C.; Jayakumar, S.; Ramaiah, N.; Vethamony, P.

    Author version: Environ. Monit. Assess., vol.169(1-4); 2010; 639-645 Dispersion and retrievability of water quality indicators during tidal cycles in coastal Salaya, Gulf of Kachchh (West coast of India). C.Mohandass *, S. Jaya Kumar, N. Ramaiah...; Brookings et al. 1985), affect ambient nutrient concentrations as well as water quality. Understanding their influence is critical to both basic ecology of tidal creeks and for evolving sampling protocols and pollutant-mitigation advisories. Lindquist...

  10. Offshore limit of coastal ocean variability identified from hydrography and altimeter data in the eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Antony, M.K.; Swamy, G.N.; Somayajulu, Y.K.

    In this communication, we describe a hitherto-unknown offshore limit to the coastal ocean variability signatures away from the continental shelf in the eastern Arabian Sea, based on hydrographic observations and satellite altimeter (TOPEX...

  11. Sea truth validation of sea WiFS ocean colour sensor in the coastal waters of the eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Desa, E.S.; Suresh, T.; Matondkar, S.G.P.; Desa, E.

    In this paper we report bio-optical measurements made during an ocean colour validation cruise SK 149C in November 1999 of the research vessel Sagar Kanya in the coastal waters of the Eastern Arabian Sea. The chlorophyll concentration...

  12. On the Coastal Dynamics of Sea Level Rise: A case study in the Northern Gulf of Mexico

    Science.gov (United States)

    Hagen, S. C.

    2012-12-01

    One of the most prominent aspects of global climate change is sea level rise (SLR). With over half of the U.S. population living within 50 miles of the coast, SLR has the potential to considerably impact both human and ecological habitats. Effects of SLR will be felt along coastal beaches, estuarine waters, barrier islands, submerged aquatic vegetation beds, sand and mud flats, oyster reefs and tidal and freshwater wetlands. The Gulf of Mexico coast sustains a diverse habitat including delta marshes, lower river floodplain forests, and oyster reefs, which provide critical habitats for many commercially important species. How we choose to study these complex processes and the adaptation tools that we develop may determine our ability to sustain the human and ecological habitats. The purpose of this presentation is to examine the dynamic effects of SLR to the coasts and coastal habitats of the Northern Gulf of Mexico and to compare and contrast those results with a simpler bathtub model (static) approach. Dynamic assessments will be presented through integrated models representing wave, tidal, overland, bay and biological processes. The models are applied to regions of the Northern Gulf to simulate hydrodynamic properties including waves, tides, and surge, and to estimate impacts to coastal marshes, wetlands and estuaries. Results strongly indicate the importance of simulating the dynamical processes.

  13. EAARL Coastal Topography and Imagery-Naval Live Oaks Area, Gulf Islands National Seashore, Florida, 2007

    Science.gov (United States)

    Nagle, David B.; Nayegandhi, Amar; Yates, Xan; Brock, John C.; Wright, C. Wayne; Bonisteel, Jamie M.; Klipp, Emily S.; Segura, Martha

    2010-01-01

    These remotely sensed, geographically referenced color-infrared (CIR) imagery and elevation measurements of lidar-derived bare-earth (BE) topography, first-surface (FS) topography, and canopy-height (CH) datasets were produced collaboratively by the U.S. Geological Survey (USGS), St. Petersburg Science Center, St. Petersburg, FL; the National Park Service (NPS), Gulf Coast Network, Lafayette, LA; and the National Aeronautics and Space Administration (NASA), Wallops Flight Facility, VA. This project provides highly detailed and accurate datasets of the Naval Live Oaks Area in Florida's Gulf Islands National Seashore, acquired June 30, 2007. The datasets are made available for use as a management tool to research scientists and natural-resource managers. An innovative airborne lidar instrument originally developed at the NASA Wallops Flight Facility, and known as the Experimental Advanced Airborne Research Lidar (EAARL), was used during data acquisition. The EAARL system is a raster-scanning, waveform-resolving, green-wavelength (532-nanometer) lidar designed to map near-shore bathymetry, topography, and vegetation structure simultaneously. The EAARL sensor suite includes the raster-scanning, water-penetrating full-waveform adaptive lidar, a down-looking red-green-blue (RGB) digital camera, a high-resolution multispectral CIR camera, two precision dual-frequency kinematic carrier-phase GPS receivers, and an integrated miniature digital inertial measurement unit, which provide for sub-meter georeferencing of each laser sample. The nominal EAARL platform is a twin-engine Cessna 310 aircraft, but the instrument may be deployed on a range of light aircraft. A single pilot, a lidar operator, and a data analyst constitute the crew for most survey operations. This sensor has the potential to make significant contributions in measuring sub-aerial and submarine coastal topography within cross-environmental surveys. Elevation measurements were collected over the survey area

  14. Monitoring Crustal Movement of the Coastal Zone in Eastern China with GPS Technique

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    In this paper, various dominating factors affecting crustal movement of the coastal zone in eastern China are analyzed, and major characteristics of crustal movement are summarized. Subduction of the pacific plate and Philippine plate and southeastward "escape" of Qinghai-Tibet plateau are believed to be dominating factors affecting crustal movement of that zone. Undoubtedly, it is a best way to monitor this kind of large-scale crustal movement with GPS technique. The feasibility of monitoring crustal m...

  15. Nutrient dynamics in tropical rivers, lagoons, and coastal ecosystems of eastern Hainan Island, South China Sea

    OpenAIRE

    Li, R. H.; Liu, S.M.; Li, Y. W.; Zhang, G.L.; Ren, J. L.; Zhang, J.

    2014-01-01

    Nutrient dynamics based on field observations made along the eastern Hainan Island during the period 2006–2009 were investigated to understand nutrient biogeochemical processes, and to provide an overview of human perturbations of coastal ecosystems in this tropical region. The rivers showed seasonal variations in nutrient concentrations, with enrichment of dissolved inorganic nitrogen and dissolved silicate, and depletion of PO43−. High riverine concentrations of nitr...

  16. Nutrient dynamics in tropical rivers, estuarine-lagoons, and coastal ecosystems along the eastern Hainan Island

    OpenAIRE

    Li, R. H.; Liu, S.M.; Li, Y. W.; Zhang, G.L.; Ren, J. L.; J. Zhang

    2013-01-01

    Nutrient dynamics were studied along the eastern Hainan Island based on field observations during 2006–2009, to understand nutrient biogeochemical processes and to have an overview of human perturbations on coastal ecosystems in this tropical region. The concentrations of nutrients in the rivers had seasonal variations enriched with dissolved inorganic nitrogen (DIN). High riverine concentrations of nitrate were mainly originated from agricultural fertilizer input. The ratios of DIN : ...

  17. Holocene coastal carbonates and evaporites of the southern Arabian Gulf and their ancient analogues

    Science.gov (United States)

    Alsharhan, A. S.; Kendall, C. G. St. C.

    2003-06-01

    The Holocene sediments of the coast of the United Arab Emirates in the southeastern Arabian Gulf are frequently cited in the literature as type examples for analogous assemblages of carbonates, evaporites and siliciclastics throughout the geologic record. This paper is intended as a convenient single source for the description of sediments of this region, providing information on how to reach the classic localities and some of the analogs. The Holocene sediments of the region accumulate over an area that is 500 km long and up to 60 km wide. The sediments collecting offshore are predominantly pelecypod sands mixed with lime and argillaceous mud, with these latter fine sediments increasing as the water deepens. The pelecypod-rich sediments also collect east of Abu Dhabi Island both in the deeper tidal channels between the barrier island lagoons and in deeper portions of the protected lagoons. West of Abu Dhabi Island the shallow water margin is the site of coral reefs and coralgal sands, whereas to the east oolites accumulate on the tidal deltas of channels located between barrier islands. Grapestones accumulate to the lee of the reefs and the oolite shoals where cementation becomes more common. They are particularly common on the less protected shallow water margins of the lagoons west of Abu Dhabi Island. Pelleted lime muds accumulate in the lagoons in the lee of the barrier islands of the eastern Abu Dhabi. Lining the inner shores of the protected lagoons of Abu Dhabi and on other islands to the west are cyano-bacterial mats and mangrove swamps. Landward of these, a prograding north facing shoreline is formed by supratidal salt flats (sabkhas), in which evaporite minerals are accumulating. This paper describes the localities associated with (1) the mangrove swamps of the west side of the Al Dhabaiya peninsula; (2) the indurated cemented carbonate crusts, cyanobacterial flats and sabkha evaporites on the shore of the Khor al Bazam south of Qanatir Island; (3) the

  18. Using Acoustic Tomography to Monitor Deep Ocean Currents in the Eastern Gulf of Mexico

    Science.gov (United States)

    2010-06-01

    Toward the improved prediction and monitoring of deep-water currents and eddies in the Gulf of Mexico , the Gulf Eddy Monitoring System group (GEMS...proposes that a network of acoustic transmitter receiver pairs be deployed in the northeastern Gulf of Mexico . Acoustic travel times are inverted to

  19. Ferromanganese concretions of the eastern Gulf of Finland - Environmental role and effects of submarine mining

    Science.gov (United States)

    Zhamoida, Vladimir; Grigoriev, Andrey; Ryabchuk, Daria; Evdokimenko, Anton; Kotilainen, Aarno T.; Vallius, Henry; Kaskela, Anu M.

    2017-08-01

    In 2006-2008, experimental under-water extraction of shallow-water concretions was fulfilled in the eastern Gulf of Finland (water depth 25-28.5 m) using a dredge pump vessel. A study of this area carried out in 2011-2015 has shown that within the trenches (1 m depth) left by a mining vessel, previously slow clastic sedimentation was replaced by high (up to 1.5 cm/year) deposition of mud. Spheroidal concretions, remaining within the trenches, are mainly found buried in the sediments. A geochemical structure of concretions sampled within the area of extraction differs from normal geochemical structures of concretions from undisturbed areas. Median concentrations of SiO2, CaO, and TiO2 in concretions from the area of mining are significantly higher than their median concentrations in concretions from undisturbed areas, while median concentrations of MgO, MnO, Co, Mo are significantly lower. This is a result of the selective removal of elements from dissolving concretions. Concretions are characterized by domination of the oxide and hydroxide forms of the elements occurrence and high content of humic organic forms. The environmental impact of concretion growth and dissolution considering the large volume of metals and phosphorous involved in these processes can be regarded as significant.

  20. The vertical distribution of zooplankton in the eastern Gulf of Mexico

    Science.gov (United States)

    Hopkins, Thomas L.

    1982-09-01

    The zooplankton community in the eastern Gulf of Mexico was investigated to determine the quantity and taxonomic composition of forage available to higher trophic levels and to provide a data base for future trophodynamic modelling. Standing stock (1.2 g m -2, dw) in the upper 1000 m is in the range for oligotrophic low-latitude boundary currents but is greater than in central gyre areas. Abundance decreases exponentially with depth, over half the biomass occuring in the upper 200 m. Diel variations are apparent, the greatest differences in biomass occuring in the upper 50 m and at 300 to 350 m. Copepods were dominant, contributing over 80% of the number and half the net-caught biomass. The zooplankton community is diverse, 21 genera individually exceeding 1% of the biomass in the 0 to 100-m layer. Grazers (herbivores, detritivores, omnivores) were 66% of the 0 to 1000-m standing stock and carnivores 34%, their biomass in the epipelagic zone above the base of the thermocline (150 m) at night increasing 46 and 57%, respectively. Zooplankton biomass available as forage for higher trophic levels is most concentrated in the upper 50 m, whereas, paradoxically, the zooplanktivorous micronekton, the myctophid fishes in particular, are centered deeper, primarily between 50 and 150 m.

  1. Characterization of Trichodesmium-associated viral communities in the eastern Gulf of Mexico.

    Science.gov (United States)

    Brown, Julia M; LaBarre, Brenna A; Hewson, Ian

    2013-06-01

    Trichodesmium surface aggregations shape the co-occurring microbial community by providing organic carbon and nitrogen and surfaces on which microorganisms can aggregate. Rapid collapse of Trichodesmium aggregations leads to drastic changes in the chemical and physical properties of surrounding waters, eliciting a response from the microbial community and their associated viruses. Three viral metagenomes were constructed from experimentally lysed Trichodesmium collected from two locations in the eastern Gulf of Mexico. Trichodesmium were either treated with mitomycin C to induce potential lysogens or incubated in the absence of mitomycin C. Comparative analyses of viral contiguous sequences indicated that viral composition was responsive to treatment type. Cyanophages were more represented within incubations treated with mitomycin C, while gammaproteobacterial phages were more represented within the untreated incubation. The detection of latent bacteriophage integrases in both the chemically treated and untreated incubations suggests that Trichodesmium death may lead to prophage induction within associated microorganisms. While no single cyanophage-like genotype associated with Trichodesmium lysis could be identified that might point to an infectious Trichodesmium phage, reads resembling Trichodesmium were recovered. These data reveal a diverse consortium of lytic and temperate phages associated with Trichodesmium whose patterns of representation within treated and untreated libraries offer insights into the activities of host and viral communities during Trichodesmium aggregation collapse.

  2. Examining Lagrangian surface transport during a coastal upwelling in the Gulf of Finland, Baltic Sea

    Science.gov (United States)

    Delpeche-Ellmann, Nicole; Mingelaitė, Toma; Soomere, Tarmo

    2017-07-01

    We employ in-situ surface drifters and satellite derived sea surface temperature data to examine the impact that an upwelling event may have on mixing and Lagrangian transport of surrounding surface waters. The test area is located near the southern coast of the Gulf of Finland where easterly winds are known to trigger intense coastal upwellings. The analysis is based on the comparison of motions of three drifters that follow the currents in the uppermost layer with a thickness of 2 m with MODIS-based sea surface temperature data and high-quality open sea wind time series. The presence of an upwelling event superseded the classic Ekman-type drift of the surface layer and considerably slowed down the average speed of surface currents in the region affected by the upwelled cold water jet and its filaments. The drifters tended to stay amidst the surrounding surface waters. The properties of mixing were evaluated using the daily rate of temperature change along several transects. The upwelled cooler water largely kept its identity during almost the entire duration of the upwelling event. Intense mixing started at a later stage of the upwelling and continued after the end of the event when the winds that have driven the entire process began to subside.

  3. [Fish species richness evaluation in Mexican coastal lagoons: a case study in the Gulf of Mexico].

    Science.gov (United States)

    Pérez-Hernández, M A; Torres-Orozco, R E

    2000-01-01

    We analyze the origin of knowledge about fish species richness in the Tuxpan-Tampamachoco estuarine system, in Veracuz, México. A complete inventory of the fish species known to date for this system (N = 179) was elaborated from published lists and from sampling seagrass meadows of Tampamachoco Lagoon, which yielded 14 previously unknown species. When compared, the different lists showed a low similarity that may reflect differences in sampling methods and collecting strategies. Current data suggest that fish species richness in Mexican coastal lagoons (Gulf of Mexico) is not related with lagoon surface area, as has been suggested, but with the number of inventories available for each lagoon, being these a reflection of the sampling effort. A sampling design for the assessment of fish species richness in estuarine systems should consider: a) using the highest possible variety of sampling fishing gears, b) collecting in all microhabitat types and c) the preference of bimonthly or quarterly samplings for two or more years over monthly samplings in a single year.

  4. Relationship of Forest Vegetation to Soils on Geological Formations of the Oklahoma Gulf Coastal Plain

    Directory of Open Access Journals (Sweden)

    Raymond John Taylor

    2005-12-01

    Full Text Available Portions of this paper were recently presented at the Cross Timbers Symposium at the Botany 2005 Symposium in Austin, Texas. I have come to realize the importance of this data as a baseline for the composition of forests in the Gulf Coastal Plain. Since the data were collected about 40 years ago, many changes have occurred including our expanding population, increase in rural housing, construction of pipelines, and clearing for pasture and cultivation. Many of the sites studied have been modified or completely disappeared. Another important change is the tremendous expansion of Juniperus virginiana (red cedar due to absence of fire. In the sampling of these 13 forests 40 years ago, this species was found in only one stand, and as a sapling. Other invasive plants include Ligustrum sinense (privet, an evergreen shrub that can expand into clones by underground roots, and the invasive vine Lonicera sempervirens (Japanese honeysuckle which is controlled in many areas by cattle grazing. Both of these species will continue to expand and affect our native flora.

  5. Forest dynamics to precipitation and temperature in the Gulf of Mexico coastal region

    Science.gov (United States)

    Li, Tianyu; Meng, Qingmin

    2017-05-01

    The forest is one of the most significant components of the Gulf of Mexico (GOM) coast. It provides livelihood to inhabitant and is known to be sensitive to climatic fluctuations. This study focuses on examining the impacts of temperature and precipitation variations on coastal forest. Two different regression methods, ordinary least squares (OLS) and geographically weighted regression (GWR), were employed to reveal the relationship between meteorological variables and forest dynamics. OLS regression analysis shows that changes in precipitation and temperature, over a span of 12 months, are responsible for 56% of NDVI variation. The forest, which is not particularly affected by the average monthly precipitation in most months, is observed to be affected by cumulative seasonal and annual precipitation explicitly. Temperature and precipitation almost equally impact on NDVI changes; about 50% of the NDVI variations is explained in OLS modeling, and about 74% of the NDVI variations is explained in GWR modeling. GWR analysis indicated that both precipitation and temperature characterize the spatial heterogeneity patterns of forest dynamics.

  6. Forest dynamics to precipitation and temperature in the Gulf of Mexico coastal region

    Science.gov (United States)

    Li, Tianyu; Meng, Qingmin

    2016-11-01

    The forest is one of the most significant components of the Gulf of Mexico (GOM) coast. It provides livelihood to inhabitant and is known to be sensitive to climatic fluctuations. This study focuses on examining the impacts of temperature and precipitation variations on coastal forest. Two different regression methods, ordinary least squares (OLS) and geographically weighted regression (GWR), were employed to reveal the relationship between meteorological variables and forest dynamics. OLS regression analysis shows that changes in precipitation and temperature, over a span of 12 months, are responsible for 56% of NDVI variation. The forest, which is not particularly affected by the average monthly precipitation in most months, is observed to be affected by cumulative seasonal and annual precipitation explicitly. Temperature and precipitation almost equally impact on NDVI changes; about 50% of the NDVI variations is explained in OLS modeling, and about 74% of the NDVI variations is explained in GWR modeling. GWR analysis indicated that both precipitation and temperature characterize the spatial heterogeneity patterns of forest dynamics.

  7. Reproductive biology of largescale tonguesole Cynoglossus arel in coastal waters of Bandar Abbas, Persian Gulf, Iran.

    Science.gov (United States)

    Ghaffari, H; Hosseinzadeh Sahafi, H; Engelhard, G H; Mekhanik Babaei, M

    2015-03-01

    The objectives of this study were to determine the reproductive cycle of largescale tonguesole Cynoglossus arel, a commercially valuable flatfish species, in coastal waters of Bandar Abbas, along the south coast of Iran in the Persian Gulf. From October 2009 to September 2010, 905 fish were collected in monthly samples, and their length, weight, sex, gonad weight, and maturity status recorded. These data revealed that ovary weight in females is low from July to September, then increases to a peak in February followed by a decrease, indicating that the peak spawning season is from February to March with some spawning lasting until June. Males showed a corresponding seasonal pattern in testis weight, although with much less pronounced seasonal differences than gonad weight in females. Five maturity classes were described based on ovarian and testicular histology, corresponding with macroscopic analysis of gonads. The spawning season in C. arel is prolonged, similar to several other tropical flatfish species, and larger adult females tended to have an even more prolonged spawning period than smaller, presumably younger adult females. Combined, our results indicated that C. arel is a winter-to-spring batch spawner with an asynchronous type of ovarian development.

  8. Groundwater Contribution to Coastal Nutrient Loading Along the Gulf Shores of Alabama

    Science.gov (United States)

    Ellis, J.; Dimova, N. T.; Zheng, C.; Huang, L.; Tick, G. R.

    2013-05-01

    SGD, and nutrient flux to the near-shore freshwater/saltwater boundary zone and the Gulf of Mexico. This research demonstrates the success of a combined numerical modeling and field tracers approach for evaluating the contribution and significance of SGD on nutrient loading to coastal near-shore environments.

  9. Modeling coastal aquifers in a Mediterranean area: the example of Taranto gulf (southern Italy)

    Science.gov (United States)

    De Filippis, Giovanna; Giudici, Mauro; Negri, Sergio; Margiotta, Stefano; Cattaneo, Laura; Vassena, Chiara

    2015-04-01

    Water resources stored in coastal aquifers are of strategic relevance for several regions throughout the world and in particular in the Mediterranean basin. They are extremely important in areas characterized by heavy urbanization, active industrial or touristic systems, where the need for fresh water is very acute and, sometimes, they are the only water resources available. This in turn can lead to the phenomenon of seawater intrusion because of aquifer overexploitation to satisfy the demand of an increasing population in coastal plains. Furthermore, karstic aquifers are well known for their specific vulnerability to natural and human-induced contamination, due to their particular characteristics such as thin soils, point recharge in dolines and swallow holes and increased hydraulic conductivity. Within this framework, the Taranto gulf is an example of paramount importance. In fact the presence of a wide industrial area close to the city of Taranto and the numerous maritime and military activities in the harbor area favored the increase of population density in the XX century. Moreover, they constitute factors of great concern for the protection of groundwater quality and quantity, in particular for the presence of the highly-vulnerable basins of Mar Piccolo and Mar Grande. In this area, groundwater resources are stored in a karst multilayered aquifer, which is very complex from the hydrostratigraphic point of view. Furthermore, the presence of highly water-demanding activities makes the seawater intrusion phenomenon very serious, especially along the coastline. In order to characterize the groundwater dynamic in the study area, we discuss the hydraulic relationships between the different hydrostratigraphic units and between the sea and the aquifer system by developing a numerical groundwater model to test and refine the preliminary conceptual model and estimate the most uncertain hydraulic parameters. To achieve these objectives, we used different data-sets to

  10. ATM Coastal Topography-Florida 2001: Eastern Panhandle

    Science.gov (United States)

    Yates, Xan; Nayegandhi, Amar; Brock, John C.; Sallenger, A.H.; Bonisteel, Jamie M.; Klipp, Emily S.; Wright, C. Wayne

    2009-01-01

    These remotely sensed, geographically referenced elevation measurements of Lidar-derived first surface (FS) topography were produced collaboratively by the U.S. Geological Survey (USGS), Florida Integrated Science Center (FISC), St. Petersburg, FL, and the National Aeronautics and Space Administration (NASA), Wallops Flight Facility, VA. This project provides highly detailed and accurate datasets of the eastern Florida panhandle coastline, acquired October 2, 2001. The datasets are made available for use as a management tool to research scientists and natural resource managers. An innovative scanning Lidar instrument originally developed by NASA, and known as the Airborne Topographic Mapper (ATM), was used during data acquisition. The ATM system is a scanning Lidar system that measures high-resolution topography of the land surface and incorporates a green-wavelength laser operating at pulse rates of 2 to 10 kilohertz. Measurements from the laser-ranging device are coupled with data acquired from inertial navigation system (INS) attitude sensors and differentially corrected global positioning system (GPS) receivers to measure topography of the surface at accuracies of +/-15 centimeters. The nominal ATM platform is a Twin Otter or P-3 Orion aircraft, but the instrument may be deployed on a range of light aircraft. Elevation measurements were collected over the survey area using the ATM system, and the resulting data were then processed using the Airborne Lidar Processing System (ALPS), a custom-built processing system developed in a NASA-USGS collaboration. ALPS supports the exploration and processing of Lidar data in an interactive or batch mode. Modules for presurvey flight line definition, flight path plotting, Lidar raster and waveform investigation, and digital camera image playback have been developed. Processing algorithms have been developed to extract the range to the first and last significant return within each waveform. ALPS is routinely used to create

  11. Late Miocene extension in coastal Sonora, México: Implications for the evolution of dextral shear in the proto-Gulf of California oblique rift

    Science.gov (United States)

    Darin, M. H.; Bennett, S. E. K.; Dorsey, R. J.; Oskin, M. E.; Iriondo, A.

    2016-12-01

    The timing, kinematics, and processes responsible for the rapid transition from subduction to oblique rifting and the localization of the Pacific-North America plate boundary in the Gulf of California are not well understood. Well exposed volcanic rocks deposited between 15 and 10 Ma in the Sierra Bacha (coastal Sonora, México) preserve a record of late Miocene deformation on the eastern rifted margin of the Gulf of California and offer new insights into the timing and kinematic evolution of oblique rifting. Detailed geologic mapping, fault kinematic analysis, U-Pb and 40Ar/39Ar geochronology, and paleomagnetic data reveal that the > 2 km-thick composite volcanic section is cut by a series of southwest-dipping, domino-style normal faults and uniformly tilted down-to-the-northeast. Palinspastic cross-section restoration suggests that the region experienced ca. 55-60% northeast-southwest-directed extension between 11.7 and 10-9 Ma. Fault kinematic data reflect relatively minor dextral transtension either following or during the later stages of extension. Paleomagnetic results indicating modest clockwise vertical-axis block rotation suggest that dextral shear was concentrated in the southwest of the study area near the modern coastline. These results support an emerging model in which dextral strain was not ubiquitous across Sonora and did not initiate immediately following the 12.5 Ma transition from subduction to oblique rifting. Instead, strain east of the Baja California microplate at this latitude evolved from extension-dominated transtension prior to 8 Ma to dextral shear-dominated transtension by 7-6 Ma. The onset of dextral shear in coastal Sonora likely resulted from an increase in rift obliquity due to a change in relative plate motion direction at 8 Ma. The increase in rift obliquity and resultant onset of significant strike-slip faulting played a crucial role in facilitating subsequent plate boundary localization and marine incursion in the northern Gulf

  12. Ball clay and bentonite deposits of the central and western Gulf of Mexico Coastal Plain, United States

    Science.gov (United States)

    Hosterman, John W.

    1984-01-01

    The Gulf of Mexico Coastal Plain produces approximately 85 percent of the ball clay used in the United States. The best commercial-grade clay deposits are composed of poorly crystalline kaolinite and small amounts of Md illite and (or) smectite. Sand and silt and iron oxide minerals are virtually absent, but quartz is present in the clay-size fraction. The best grade ball clays are found as lenses limited to the Wilcox Group (Paleocene and lower Eocene) and Claiborne Group (middle Eocene). Reserves of ball clay are sufficient for the present, but because of the lenticular nature of the clay bodies, close-spaced drilling, detailed sampling, mineralogic analyses, and ceramic testing are needed to prove future reserves.Approximately 11 percent of the total bentonite produced in the United States comes from the Gulf Coast region. The commercial-grade bentonites are composed primarily of smectite with little or no Md illite and kaolinite. The nonclay impurities are quartz, feldspar, muscovite, biotite, calcite, dolomite, gypsum, and heulandite. Commercial bentonites occur in the Upper Cretaceous formations in Alabama and Mississippi, in Paleocene formations in Mississippi and Tennessee, and in Eocene and Miocene formations in Texas. The demand for low-swelling bentonite of the Gulf Coastal Plain has not increased along with the demand for swelling bentonite; therefore the reserves are adequate.

  13. Near-coastal ocean variability off southern Tamaulipas - northern Veracruz, western Gulf of Mexico, during spring-summer 2013

    Science.gov (United States)

    Rivas, David

    2016-04-01

    Six months of observations from a near-coastal mooring deployed off southern Tamaulipas-northern Veracruz coast (western Gulf of Mexico) during spring-summer 2013 provides velocity, temperature, salinity, sea level, and dissolved oxygen series in a region which ocean dynamics is still poorly understood. As shown in a preceding analysis of this region's winter circulation for winter 2012-2013, coastal trapped motions associated with the regional invasion of synoptic cold fronts modulate the local variability; this pattern remains in the spring 2013, when even more intense events of alongshore flow (>50 cm/s) are observed. This intensified flow is associated with a significant decrease in the dissolved oxygen, most probably related to an influence of hypoxic waters coming from the northern Gulf. In late spring-mid summer, the wind pattern corresponds to persistent southeasterly winds that favor the occurrence of a local upwelling, which maintains a local thermal reduction (>3 degrees Celsius) and is associated with a persistent northward flow (>30 cm/s). The late summer was characterized by a significant tropical-cyclone activity, when a depression, a storm, and a hurricane affected the western Gulf. These tropical systems caused an intense precipitation and hence an important intensification of the local riverine discharge, and the winds enhanced the mixing of such riverine waters, via mostly kinetic stirring and Ekman pumping.

  14. Contrasting soils and landscapes of the Piedmont and Coastal Plain, eastern United States

    Science.gov (United States)

    Markewich, H.W.; Pavich, M.J.; Buell, G.R.

    1990-01-01

    sequences that can be correlated along valleys for tens of kilometers. Coastal Plain soils are typically as thick as 2 to 8 m, have high sand content throughout, and have sandy epipedons. These epipedons consist of both A and E horizons and are 1 to 4 m thick. In Coastal Plain soils, the boundaries are transitional between the solum and the underlying parent material and between weathered and unweathered parent material. Infiltration rates for Coastal Plain soils are typically higher at 13-28 cm/h, than are those for Piedmont soils. Indeed, for unconsolidated quartz sand, rates may exceed 50 cm/h. Water moves directly from the soil into the parent material through intergranularpores with only minor channelization along macropores, joints, and fractures. The comparatively high infiltration capacity results in relatively low surface runoff, and correspondingly less erosion than on the Piedmont uplands. Due to differences in Piedmont and Coastal Plain erosion rates, topographic inversion is common along the Fall Zone; surfaces on Cenozoic sedimentary deposits of the Coastal Plain are higher than erosional surfaces on regolith weathered from late Precambrian to early Paleozoic crystalline rocks of the Piedmont. Isotopic, paleontologic, and soil data indicate that Coastal Plain surficial deposits are post-middle Miocene to Holocene in age, but most are from 5 to 2 Ma. Thus, the relatively uneroded surfaces comprise a Pliocene landscape. In the eastern third of the Coastal Plain, deposits that are less than 3.5 Ma include alluvial terraces, marine terraces and barrier/back-barrier complexes as morphostratigraphic units that cover thousands of square kilometers. Isotopic and soil data indicate that eastern Piedmont soils range from late Pliocene to Pleistocene in age, but are predominantly less than 2 Ma old. Thus, the eroded uplands of the Piedmont "peneplain" comprise a Pleistocene landscape. ?? 1990.

  15. Profiles and inventories of organic pollutants in sediments from the central Beibu Gulf and its coastal mangroves.

    Science.gov (United States)

    Kaiser, David; Schulz-Bull, Detlef E; Waniek, Joanna J

    2016-06-01

    Sediment cores from the central Beibu Gulf and its northern coastal mangroves were analyzed for polycyclic aromatic hydrocarbons (PAH), the organo-chlorine pesticides dichlorodiphenyltrichloroethane (DDT) and hexachlorobenzene (HCB), and polychlorinated biphenyls (PCB), to reconstruct the organic pollution history of developing south-west China. Reflecting regional development, in the gulf ∑PAH (38-74 ng g(-1)) decreased towards the surface after peak concentrations near 10 cm, while ∑DDT (ND - 0.5 ng g(-1)) increased due to fresh inputs, and HCB (ND - 0.04 ng g(-1)) occurred only in surface sediments. Profiles in mangrove sediments showed a continuing local scale increase in ∑PAH (29-438 ng g(-1)) as well as ∑DDT (0.2-41.0 ng g(-1)) and HCB (0.01-1.01 ng g(-1)) pollution, despite some variability. No trend was evident for ∑PCB (ND - 0.22 ng g(-1)), which was not detected in the central gulf. Calculated loads estimate that 2816 ng cm(-2) PAHs and 7 ng cm(-2) DDTs are stored in depositional areas of the Beibu Gulf. Mangrove sediments, threatened by land-use-change, contain 1400-4600 ng cm(-2) PAHs and 34-39 ng cm(-2) DDTs.

  16. Simulation of tsunami generation, propagation and coastal inundation in the Eastern Mediterranean

    Directory of Open Access Journals (Sweden)

    A. G. Samaras

    2015-05-01

    Full Text Available In the present work, an advanced tsunami generation, propagation and coastal inundation 2-DH model (i.e. 2-D Horizontal model based on the higher-order Boussinesq equations – developed by the authors – is applied to simulate representative earthquake-induced tsunami scenarios in the Eastern Mediterranean. Two areas of interest were selected after evaluating tsunamigenic zones and possible sources in the region: one at the Southwest of the island of Crete in Greece and one at the East of the island of Sicily in Italy. Model results are presented in the form of extreme water elevation maps, sequences of snapshots of water elevation during the propagation of the tsunamis, and inundation maps of the studied low-lying coastal areas. This work marks one of the first successful applications of a fully nonlinear model for the 2-DH simulation of tsunami-induced coastal inundation; acquired results are indicative of the model's capabilities, as well of how areas in the Eastern Mediterranean would be affected by eventual larger events.

  17. Coastal Wetland Ecosystem Responses to Climate Change: the Role of Macroclimatic Drivers along the Northern Gulf of Mexico

    Science.gov (United States)

    Osland, M. J.; Enwright, N.; Day, R. H.; Gabler, C. A.; Stagg, C. L.; From, A. S.

    2014-12-01

    Across the globe, macroclimatic drivers greatly influence coastal wetland ecosystem structure and function. However, changing macroclimatic conditions are rarely incorporated into coastal wetland vulnerability assessments. Here, we quantify the influence of macroclimatic drivers upon coastal wetland ecosystems along the Northern Gulf of Mexico (NGOM) coast. From a global perspective, the NGOM coast provides several excellent opportunities to examine the effects of climate change upon coastal wetlands. The abundant coastal wetland ecosystems in the region span two major climatic gradients: (1) a winter temperature gradient that crosses temperate to tropical climatic zones; and (2) a precipitation gradient that crosses humid to semi-arid zones. We present analyses where we used geospatial data (historical climate, hydrology, and coastal wetland coverage) and field data (soil, elevation, and plant community composition and structure) to quantify climate-mediated ecological transitions. We identified winter climate and precipitation-based thresholds that separate mangrove forests from salt marshes and vegetated wetlands from unvegetated wetlands, respectively. We used simple distribution and abundance models to evaluate the potential ecological effects of alternative future climate change scenarios. Our results illustrate and quantify the importance of macroclimatic drivers and indicate that climate change could result in landscape-scale changes in coastal wetland ecosystem structure and function. These macroclimate-mediated ecological changes could affect the supply of some ecosystem goods and services as well as the resilience of these ecosystems to stressors, including accelerated sea level rise. Collectively, our findings highlight the importance of incorporating macroclimatic drivers within future-focused coastal wetland vulnerability assessments.

  18. Species profiles: Life histories and environmental requirements of coastal fishes and invertebrates (Gulf of Mexico): Blue crab. [Callinectes sapidus

    Energy Technology Data Exchange (ETDEWEB)

    Perry, H.M.; McIlwain, T.D.

    1986-06-01

    The blue crab, Callinectes sapidus, is common in tidal marsh estuaries and coastal waters of the Gulf of Mexico, occupying a variety of habitats depending upon the physiological requirements of each particular stage in its life history. Spawning occurs from spring through fall in high salinity estuarine and/or coastal waters. Development through the 7 zoeal stages requires approximately 31 days and occurs offshore. The megalopal stage is usually completed within a week. Recruitment to the estuary occurs during the megalopal stage. Molt to the first crab takes place within the estuary. Juveniles exhibit wide seasonal and areal distribution. Growth is rapid and blue crabs in the Gulf of Mexico may reach maturity within a year. Factors affecting growth and survival include food availability, predation, substratum, available habitat, temperature, salinity and pollutants. Blue crabs do not conform to specific trophic levels and are characterized as opportunistic benthic omnivores. Their diverse feeding habits and their importance as prey species for a variety of organisms make them an integral part of coastal ecosystems.

  19. Net primary productivity, upwelling and coastal currents in the Gulf of Ulloa, Baja California, México

    Directory of Open Access Journals (Sweden)

    E. González-Rodríguez

    2012-08-01

    Full Text Available The Gulf of Ulloa, a highly productive area off the western coast of the Baja California Peninsula, is examined for five successive years (2003–2007 by using satellite data and seasonal net primary productivity (NPP estimates obtained from a vertical generalised production model. The results identify that northwestern winds blow parallel to the coast throughout the year. However, highest NPP occurs from March to June. During this period, an equatorward coastal current transports water from neighbouring upwelling areas to the northern Gulf of Ulloa and in combination with local upwelling, which injects nutrients into the euphotic zone, produce the observed increase in NPP. The opposite situation occurs in late summer when a warm poleward current of tropical characteristics arrives and inhibits the productivity in the whole region and generates the yearly lowest NPP levels. Our findings reveal the importance of lateral advection in the modulation of the primary productivity in this subtropical upwelling region.

  20. Examining coastal upwellings from a Lagrangian perspective in the Gulf of Finland, Baltic Sea

    Science.gov (United States)

    Delpeche-Ellmann, Nicole; Mingelaitė, Toma; Soomere, Tarmo

    2017-04-01

    This study examines from a Lagrangian perspective the impact that an upwelling event may have on mixing and the Lagrangian transport of surrounding surface waters. To accomplish this we employ in-situ surface drifters (that follow the currents in the uppermost layer with a thickness of 2 m), satellite derived sea surface temperature data (obtained from the MODIS Aqua satellite), and high-quality open sea wind time series. The study area is located near the southern coast of the Gulf of Finland where easterly winds are known to trigger intense coastal upwellings. The properties of mixing were evaluated using the daily rate of temperature change along several transects. Results show that unlike classical upwelling events that normally show cooler water hugging the coastline in a longitudinal direction, this upwelling event instead took the form of transverse jets that protruded as much as 40-45 km from the coastline at distinct locations. Interestingly, the surface drifters show that the presence of the upwelling event superseded classic Ekman-type drift of the surface layer and in effect slowed down the average speed of surface currents in the surrounding waters. It was discovered that intense and long-lasting upwelling events may contain three distinct stages, which was clearly influenced by the wind intensity: During the first stage (strong winds) the cooler water is brought to the surface. The second stage (strong winds) is characterized by the presence of coherent cooler water transverse jets that protrude some distance from the coast at two distinct locations and that lasted 5 days, during this stage very little mixing took place it was mainly the advection of colder water to the open sea. Whilst the third stage encompasses the presence of filaments/squirts and eventually the disintegration of these structures and intense mixing of upwelled and surrounding waters under weaker winds. Thus the upwelled cooler water largely kept its identity during almost the

  1. Abundance and size of Gulf shrimp in Louisiana's coastal estuaries following the Deepwater Horizon oil spill.

    Science.gov (United States)

    van der Ham, Joris L; de Mutsert, Kim

    2014-01-01

    The Deepwater Horizon oil spill impacted Louisiana's coastal estuaries physically, chemically, and biologically. To better understand the ecological consequences of this oil spill on Louisiana estuaries, we compared the abundance and size of two Gulf shrimp species (Farfantepeneus aztecus and Litopeneus setiferus) in heavily affected and relatively unaffected estuaries, before and after the oil spill. Two datasets were used to conduct this study: data on shrimp abundance and size before the spill were available from Louisiana Department of Wildlife and Fisheries (LDWF). Data on shrimp abundance and size from after the spill were independently collected by the authors and by LDWF. Using a Before-After-Control-Impact with Paired sampling (BACIP) design with monthly samples of two selected basins, we found brown shrimp to become more abundant and the mean size of white shrimp to become smaller. Using a BACIP with data on successive shrimp year-classes of multiple basins, we found both species to become more abundant in basins that were affected by the spill, while mean shrimp size either not change after the spill, or increased in both affected and unaffected basins. We conclude that following the oil spill abundances of both species increased within affected estuaries, whereas mean size may have been unaffected. We propose two factors that may have caused these results: 1) exposure to polycyclic aromatic hydrocarbons (PAHs) may have reduced the growth rate of shrimp, resulting in a delayed movement of shrimp to offshore habitats, and an increase of within-estuary shrimp abundance, and 2) fishing closures established immediately after the spill, may have resulted in decreased fishing effort and an increase in shrimp abundance. This study accentuates the complexities in determining ecological effects of oil spills, and the need of studies on the organismal level to reveal cause-and-effect relationships of such events.

  2. Abundance and size of Gulf shrimp in Louisiana's coastal estuaries following the Deepwater Horizon oil spill.

    Directory of Open Access Journals (Sweden)

    Joris L van der Ham

    Full Text Available The Deepwater Horizon oil spill impacted Louisiana's coastal estuaries physically, chemically, and biologically. To better understand the ecological consequences of this oil spill on Louisiana estuaries, we compared the abundance and size of two Gulf shrimp species (Farfantepeneus aztecus and Litopeneus setiferus in heavily affected and relatively unaffected estuaries, before and after the oil spill. Two datasets were used to conduct this study: data on shrimp abundance and size before the spill were available from Louisiana Department of Wildlife and Fisheries (LDWF. Data on shrimp abundance and size from after the spill were independently collected by the authors and by LDWF. Using a Before-After-Control-Impact with Paired sampling (BACIP design with monthly samples of two selected basins, we found brown shrimp to become more abundant and the mean size of white shrimp to become smaller. Using a BACIP with data on successive shrimp year-classes of multiple basins, we found both species to become more abundant in basins that were affected by the spill, while mean shrimp size either not change after the spill, or increased in both affected and unaffected basins. We conclude that following the oil spill abundances of both species increased within affected estuaries, whereas mean size may have been unaffected. We propose two factors that may have caused these results: 1 exposure to polycyclic aromatic hydrocarbons (PAHs may have reduced the growth rate of shrimp, resulting in a delayed movement of shrimp to offshore habitats, and an increase of within-estuary shrimp abundance, and 2 fishing closures established immediately after the spill, may have resulted in decreased fishing effort and an increase in shrimp abundance. This study accentuates the complexities in determining ecological effects of oil spills, and the need of studies on the organismal level to reveal cause-and-effect relationships of such events.

  3. Estimation of PFOS emission from domestic sources in the eastern coastal region of China.

    Science.gov (United States)

    Xie, Shuangwei; Lu, Yonglong; Wang, Tieyu; Liu, Shijie; Jones, Kevin; Sweetman, Andy

    2013-09-01

    Perfluorooctane sulfonate (PFOS) and related chemicals (collectively "PFOS equivalents") have been released to the environment through widespread consumer use and disposal of PFOS-containing products like carpet, leather, textiles, paper, food containers, household cleansers, etc. Accordingly, in addition to PFOS-related industries, domestic activities may also considerably contribute to the PFOS emissions in the eastern coastal region of China, which has been characterized by high industrial input. In the present study, domestic emissions of PFOS equivalents derived from municipal wastewater treatment plants were estimated at the county level, using a regression model of domestic emission density with population density and per capita disposable income as independent variables. The total emission load of PFOS equivalents from domestic sources in the eastern coastal region of China was 381kg in 2010, and large cities were prominent as the emission centers. The domestic emission density averaged 0.37g/km(2)·a for the entire study area. Generally, the Beijing-Tianjin area, Pearl River Delta and Yangtze River Delta, as the most populous and economically developed areas in China, showed significantly higher emission density. Geographical variations within individual provinces were noteworthy. The average per capita discharge load of PFOS equivalents arising from domestic activities was 1.91μg/day per capita in the eastern coastal region of China, which is consistent with previous estimates in Korea, but lower than those calculated for developed countries. In comparison, the spatial distributions of provincial PFOS emissions from domestic and industrial sources were similar to each other; however, the latter was much larger for all the provinces.

  4. Nutrient dynamics in tropical rivers, estuarine-lagoons, and coastal ecosystems along the eastern Hainan Island

    Science.gov (United States)

    Li, R. H.; Liu, S. M.; Li, Y. W.; Zhang, G. L.; Ren, J. L.; Zhang, J.

    2013-06-01

    Nutrient dynamics were studied along the eastern Hainan Island based on field observations during 2006-2009, to understand nutrient biogeochemical processes and to have an overview of human perturbations on coastal ecosystems in this tropical region. The concentrations of nutrients in the rivers had seasonal variations enriched with dissolved inorganic nitrogen (DIN). High riverine concentrations of nitrate were mainly originated from agricultural fertilizer input. The ratios of DIN : PO43- ranged from 37 to 1063, suggesting preferential PO43- relative to nitrogen in the rivers. The areal yields of dissolved silicate (DSi) varied from 76 to 448 × 103 mol km-2 yr-1 due to erosion over the drainage area, inducing high levels of DSi among worldwide tropical systems. Aquaculture ponds contained high concentrations of NH4+ (up to 157 μM) and DON (up to 130 μM). Particulate phosphorus concentrations (0.5 ∼1.4 μM) were in lower level comparied with estuaries around the world. Particulate silicate levels in rivers and lagoons were lower than global average level. Nutrient biogeochemistry in coastal areas were affected by human activities (e.g. aquaculture, agriculture), as well as natural events such as typhoon. Nutrient concentrations were low because open sea water dispersed land-derived nutrients. Nutrient budgets were built based on a steady-state box model, which showed that riverine fluxes would be magnified by estuarine processes (e.g. regeneration, desorption) in the Wenchanghe/Wenjiaohe Estuary, Wanquan River estuary, and the Laoyehai Lagoon except in the Xiaohai Lagoon. Riverine and groundwater input were the major sources of nutrients to the Xiaohai Lagoon and the Laiyehai Lagoon, respectively. Riverine input and aquaculture effluent were the major sources of nutrients to the eastern coastal of Hainan Island. Nutrient inputs to the coastal ecosystem can be increased by typhoon-induced runoff of rainwater, and phytoplankton bloom in the sea would be

  5. Nutrient dynamics in tropical rivers, lagoons, and coastal ecosystems of eastern Hainan Island, South China Sea

    Science.gov (United States)

    Li, R. H.; Liu, S. M.; Li, Y. W.; Zhang, G. L.; Ren, J. L.; Zhang, J.

    2014-01-01

    Nutrient dynamics based on field observations made along the eastern Hainan Island during the period 2006-2009 were investigated to understand nutrient biogeochemical processes, and to provide an overview of human perturbations of coastal ecosystems in this tropical region. The rivers showed seasonal variations in nutrient concentrations, with enrichment of dissolved inorganic nitrogen and dissolved silicate, and depletion of PO43-. High riverine concentrations of nitrate mainly originated from agricultural fertilizer inputs. The DIN : PO43- ratios ranged from 37 to 1063, suggesting preferential depletion of PO43- relative to nitrogen in rivers. Chemical weathering in the drainage area might explain the high levels of dissolved silicate. Aquaculture ponds contained high concentrations of NH4+ and dissolved organic nitrogen. The particulate phosphorus concentrations in the study area were lower than those reported for estuaries worldwide. The particulate silicate levels in rivers and lagoons were lower than the global average level. Nutrient biogeochemistry in coastal areas was affected by human activities (e.g., aquaculture, agriculture), and by natural phenomena including typhoons. The nutrient concentrations in coastal waters were low because of dispersion of land-derived nutrients in the sea. Nutrient budgets were built based on a steady-state box model, which showed that riverine fluxes are magnified by estuarine processes (e.g., regeneration, desorption) in estuaries and Laoyehai Lagoon, but not in Xiaohai Lagoon. Riverine and groundwater inputs were the major sources of nutrients to Xiaohai and Laoyehai lagoons, respectively, and riverine inputs and aquaculture effluents were the major sources for the eastern coast of Hainan Island. Nutrient inputs to the coastal ecosystem increased with typhoon-induced runoff of rainwater, elucidating the important influence of typhoons on small tropical rivers.

  6. Nutrient dynamics in tropical rivers, estuarine-lagoons, and coastal ecosystems along the eastern Hainan Island

    Directory of Open Access Journals (Sweden)

    R. H. Li

    2013-06-01

    Full Text Available Nutrient dynamics were studied along the eastern Hainan Island based on field observations during 2006–2009, to understand nutrient biogeochemical processes and to have an overview of human perturbations on coastal ecosystems in this tropical region. The concentrations of nutrients in the rivers had seasonal variations enriched with dissolved inorganic nitrogen (DIN. High riverine concentrations of nitrate were mainly originated from agricultural fertilizer input. The ratios of DIN : PO43− ranged from 37 to 1063, suggesting preferential PO43− relative to nitrogen in the rivers. The areal yields of dissolved silicate (DSi varied from 76 to 448 × 103 mol km−2 yr−1 due to erosion over the drainage area, inducing high levels of DSi among worldwide tropical systems. Aquaculture ponds contained high concentrations of NH4+ (up to 157 μM and DON (up to 130 μM. Particulate phosphorus concentrations (0.5 ∼1.4 μM were in lower level comparied with estuaries around the world. Particulate silicate levels in rivers and lagoons were lower than global average level. Nutrient biogeochemistry in coastal areas were affected by human activities (e.g. aquaculture, agriculture, as well as natural events such as typhoon. Nutrient concentrations were low because open sea water dispersed land-derived nutrients. Nutrient budgets were built based on a steady-state box model, which showed that riverine fluxes would be magnified by estuarine processes (e.g. regeneration, desorption in the Wenchanghe/Wenjiaohe Estuary, Wanquan River estuary, and the Laoyehai Lagoon except in the Xiaohai Lagoon. Riverine and groundwater input were the major sources of nutrients to the Xiaohai Lagoon and the Laiyehai Lagoon, respectively. Riverine input and aquaculture effluent were the major sources of nutrients to the eastern coastal of Hainan Island. Nutrient inputs to the coastal ecosystem can be increased by typhoon-induced runoff of rainwater, and phytoplankton bloom

  7. Thermal characteristics of a marine microcosm designed to simulate the coastal water environment of the northern Gulf of California

    Science.gov (United States)

    Idso, S. B.; Idso, K. E.

    1982-05-01

    The construction and stocking of a 15 000-liter marine microcosm is described. The microcosm is located outdoors in the arid desert environment of Tempe, Arizona and is an attempt to simulate the coastal water environment of the northern Gulf of California near Puerto Penasco, Mexico. Temperature modulation is achieved by an appropriate area/volume ratio, partial shading of the water surface, and auxiliary solar panel heating. Long-term measurements demonstrate that the system is capable of accurately duplicating the mean monthly temperatures of Puerto Penasco waters throughout the entire year.

  8. Ocean Carbon and Biogeochemistry Scoping Workshop on Terrestrial and Coastal Carbon Fluxes in the Gulf of Mexico, St. Petersburg, FL

    Science.gov (United States)

    Robbins, L. L.; Coble, P. G.; Clayton, T. D.; Cai, W. J.

    2008-01-01

    Despite their relatively small surface area, ocean margins may have a significant impact on global biogeochemical cycles and, potentially, the global air-sea fluxes of carbon dioxide. Margins are characterized by intense geochemical and biological processing of carbon and other elements and exchange large amounts of matter and energy with the open ocean. The area-specific rates of productivity, biogeochemical cycling, and organic/inorganic matter sequestration are high in coastal margins, with as much as half of the global integrated new production occurring over the continental shelves and slopes (Walsh, 1991; Doney and Hood, 2002; Jahnke, in press). However, the current lack of knowledge and understanding of biogeochemical processes occurring at the ocean margins has left them largely ignored in most of the previous global assessments of the oceanic carbon cycle (Doney and Hood, 2002). A major source of North American and global uncertainty is the Gulf of Mexico, a large semi-enclosed subtropical basin bordered by the United States, Mexico, and Cuba. Like many of the marginal oceans worldwide, the Gulf of Mexico remains largely unsampled and poorly characterized in terms of its air-sea exchange of carbon dioxide and other carbon fluxes. The goal of the workshop was to bring together researchers from multiple disciplines studying terrestrial, aquatic, and marine ecosystems to discuss the state of knowledge in carbon fluxes in the Gulf of Mexico, data gaps, and overarching questions in the Gulf of Mexico system. The discussions at the workshop were intended to stimulate integrated studies of marine and terrestrial biogeochemical cycles and associated ecosystems that will help to establish the role of the Gulf of Mexico in the carbon cycle and how it might evolve in the face of environmental change.

  9. Spatial distribution and intra-annual variability of water masses on the Eastern Gulf of Cadiz seabed

    Science.gov (United States)

    Bellanco, M. J.; Sánchez-Leal, R. F.

    2016-10-01

    This paper presents the spatial distribution and intra-annual variability of seabed hydrography in the Eastern Gulf of Cadiz based on more than 10 years of near-bottom CTD observations. Well-defined water masses and a variety of mixing products are persistently sorted along three bathymetric areas occupying particular depth intervals: (i) inner shelf waters (Gibraltar driven both by an elevated MOW and a less stratified ENACW could explain the winter salinification of most of the grounds deeper than 250 m.

  10. Impact of dredged urban river sediment on a Saronikos Gulf dumping site (Eastern Mediterranean): sediment toxicity, contaminant levels, and biomarkers in caged mussels.

    Science.gov (United States)

    Tsangaris, Catherine; Strogyloudi, Evangelia; Hatzianestis, Ioannis; Catsiki, Vassiliki-Angelique; Panagiotopoulos, Ioannis; Kapsimalis, Vasilios

    2014-05-01

    Impacts of chemical contaminants associated with dumping of dredged urban river sediments at a coastal disposal area in Saronikos Gulf (Eastern Mediterranean) were investigated through a combined approach of sediment toxicity testing and active biomonitoring with caged mussels. Chemical analyses of aliphatic hydrocarbons (AHs), polycyclic aromatic hydrocarbons (PAHs), Cu, and Zn in combination with the solid phase Microtox® test were performed on sediments. Concentrations of PAHs, AHs, Cu, and Zn as well as multiple biomarkers of contaminant exposure and/or effects were measured in caged mussels. Sediments in the disposal and neighboring area showed elevated PAHs and AHs concentrations and were characterized as toxic by the solid-phase Microtox® test during and after dumping operations. Biomarker results in the caged mussels indicated sublethal effects mainly during dumping operations, concomitantly with high concentrations of PAHs and AHs in the caged mussel tissues. Cu and Zn concentrations in sediments and caged mussels were generally not elevated except for sediments at the site in the disposal area that received the major amount of dredges. High PAHs and AHs levels as well as sublethal effects in the caged mussels were not persistent after termination of operations. The combined bioassay-biomarker approach proved useful for detecting toxicological impacts of dredged river sediment disposal in sediments and the water column. Nevertheless, further research is needed to evaluate whether sediment toxicity will have long-term effects on benthic communities of the disposal area.

  11. Coastal setback line for the Kyparissiakos Gulf (Ionian Sea, Greece) according to the Mediterranean ICZM protocol

    Science.gov (United States)

    Poulos, Serafim; George, Ghionis; Karditsa, Aikaterini

    2017-04-01

    The present investigation concerns the application of the Article 8-2 of the Mediterranean ICZM protocol in the environmentally sensitive coastal dune field of the central part of the Kyparissiakos Gulf (Ionian Sea, Greece). The Kyparissiakos dune field, comprising a set of coastal ecosystems of exceptional value, needs effective ICZM and, amongst all, has to consider the issue of Sea-Level Rise (SLR). The dune field consists of "parabolic" type dunes that are stable and subjected locally to human interference. It consists of four shore-parallel dune lines: the outer (and most recently formed) 1st dune line has formed during the last 500 years, the 2nd during the last 1000 years, whilst the 3rd and 4th lines have formed not later than 1600 years BP (Poulos et al., 2012). Moreover, the four dune lines (from the youngest to the oldest) lie at distances of approximately 60 m, 100 m, 200 m and 600 m from the coastline, having maximum heights of 4 m, 6 m, 10 m, and 10-12 m, respectively. The dune field, in general, is in equilibrium with the current nearshore hydrodynamics as the width of the beach zone is greater than the maximum run-up length (not included storm surge). The maximum wave run-up height (R), relative to the mean sea level, has been calculated by applying Komar's (1998) equation: R = 0.36 ṡ g0.5 ṡ S ṡ Ho0.5 ṡ T (g: acceleration of gravity; Ho: maximum offshore wave height; T: corresponding maximum wave period; S: tangential beach slope). Thus, the wave run-up due to the highest incoming waves can reach elevations of the order of 1.6m in the case of the NW waves (Ho=6m, T=9 s) and 2m in the case of W and SW waves (Ho=6.4m, T=6.4s). These elevations correspond to 25m and 40 m of tangential distances on the beach surface, which are less than the current beach width (> 60 m). However, if the maximum wave heights coincide with the maximum storm surge (0.5 m) observed in the area, wave action can reach and erode the foot of the 1st dune line. Thus, for

  12. Detection of coastal and submarine discharge on the Florida Gulf Coast with an airborne thermal-infrared mapping system

    Science.gov (United States)

    Raabe, Ellen; Stonehouse, David; Ebersol, Kristin; Holland, Kathryn; Robbins, Lisa

    2011-01-01

    Along the Gulf Coast of Florida north of Tampa Bay lies a region characterized by an open marsh coast, low topographic gradient, water-bearing limestone, and scattered springs. The Floridan aquifer system is at or near land surface in this region, discharging water at a consistent 70-72°F. The thermal contrast between ambient water and aquifer discharge during winter months can be distinguished using airborne thermal-infrared imagery. An airborne thermal-infrared mapping system was used to collect imagery along 126 miles of the Gulf Coast from Jefferson to Levy County, FL, in March 2009. The imagery depicts a large number of discharge locations and associated warm-water plumes in ponds, creeks, rivers, and nearshore waters. A thermal contrast of 6°F or more was set as a conservative threshold for identifying sites, statistically significant at the 99% confidence interval. Almost 900 such coastal and submarine-discharge locations were detected, averaging seven to nine per mile along this section of coast. This represents approximately one hundred times the number of previously known discharge sites in the same area. Several known coastal springs in Taylor and Levy Counties were positively identified with the imagery and were used to estimate regional discharge equivalent to one 1st-order spring, discharging 100 cubic feet per second or more, for every two miles of coastline. The number of identified discharge sites is a conservative estimate and may represent two-thirds of existing features due to low groundwater levels at time of overflight. The role of aquifer discharge in coastal and estuarine health is indisputable; however, mapping and quantifying discharge in a complex karst environment can be an elusive goal. The results of this effort illustrate the effectiveness of the instrument and underscore the influence of coastal springs along this stretch of the Florida coast.

  13. Review of submarine groundwater discharge (SGD) in coastal zones of the Southeast and Gulf Coast regions of the United States with management implications.

    Science.gov (United States)

    McCoy, C A; Corbett, D R

    2009-01-01

    Groundwater serves as the primary drinking water source for over half of the coastal populations of the Southeast and Gulf Coast regions, two of the fastest growing regions in the United States. Increased demand for this resource has exceeded sustainable yields in many areas and induced saltwater intrusion of coastal aquifers. A process associated with coastal groundwater, submarine groundwater discharge (SGD), has been documented as a source of subsurface fluids to coastal ocean environments throughout the Southeast and Gulf Coast regions and is potentially a significant contributor to nearshore water and geochemical budgets (i.e., nutrients, carbon, trace metals) in many coastal regions. The importance of groundwater as a drinking water source for coastal populations and the influences of submarine groundwater discharge to the coastal ocean warrant increased research and management of this resource. This paper highlights findings from recent SGD studies on three hydrogeologically different continental margins (Onslow Bay, NC, southern Florida, and the Louisiana margin), provides background on the common methods of assessing SGD, and suggests a regional management plan for coastal groundwater resources. Suggested strategies call for assessments of SGD in areas of potentially significant discharge, development of new monitoring networks, and the incorporation of a regional coastal groundwater resources council.

  14. Spatio-temporal variability of hydro-chemical characteristics of coastal waters of Gulf of Mannar Marine Biosphere Reserve (GoMMBR), South India

    Science.gov (United States)

    Kathiravan, K.; Natesan, Usha; Vishnunath, R.

    2014-11-01

    The intention of this study was to appraise the spatial and temporal variations in the physico-chemical parameters of coastal waters of Rameswaram Island, Gulf of Mannar Marine Biosphere Reserve, south India, using multivariate statistical techniques, such as cluster analysis, factor analysis and principal component analysis. Spatio-temporal variations among the physico-chemical parameters are observed in the coastal waters of Gulf of Mannar, especially during northeast and post monsoon seasons. It is inferred that the high loadings of pH, temperature, suspended particulate matter, salinity, dissolved oxygen, biochemical oxygen demand, chlorophyll a, nutrient species of nitrogen and phosphorus strongly determine the discrimination of coastal water quality. Results highlight the important role of monsoonal variations to determine the coastal water quality around Rameswaram Island.

  15. Potential of MODIS EVI in Identifying Hurricane Disturbance to Coastal Vegetation in the Northern Gulf of Mexico

    Directory of Open Access Journals (Sweden)

    Fugui Wang

    2009-12-01

    Full Text Available Frequent hurricane landfalls along the northern Gulf of Mexico, in addition to causing immediate damage to vegetation, also have long term effects on coastal ecosystem structure and function. This study investigated the utility of using time series enhanced vegetation index (EVI imagery composited in MODIS product MOD13Q1 for assessing hurricane damage to vegetation and its recovery. Vegetation in four US coastal states disturbed by five hurricanes between 2002 and 2008 were explored by change imagery derived from pre- and post-hurricane EVI data. Interpretation of the EVI changes within months and between years distinguished a clear disturbance pattern caused by Hurricanes Katrina and Rita in 2005, and a recovering trend of the vegetation between 2005 and 2008, particularly within the 100 km coastal zone. However, for Hurricanes Gustav, Ike, and Lili, the disturbance pattern which varied by the change imagery were not noticeable in some images due to lighter vegetation damage. The EVI pre- and post-hurricane differences between two adjacent years and around one month after hurricane disturbance provided the most likely damage area and patterns. The study also revealed that as hurricanes damaged vegetation in some coastal areas, strong precipitation associated with these storms may benefit growth of vegetation in other areas. Overall, the study illustrated that the MODIS product could be employed to detect severe hurricane damage to vegetation, monitor vegetation recovery dynamics, and assess benefits of hurricanes to vegetation.

  16. Bio-Optical Properties of Two Neigboring Coastal Regions of Tropical Northern Australia: The Van Diemen Gulf and Darwin Harbour

    Directory of Open Access Journals (Sweden)

    David Blondeau-Patissier

    2017-05-01

    Full Text Available This study focuses on the seasonal and spatial characterization of inherent optical properties and biogeochemical concentrations in the Van Diemen Gulf and Darwin Harbour, two neighboring tropical coastal environments of Northern Australia that exhibit shallow depths (~20 m, large (>3 m semi-diurnal tides, and a monsoonal climate. To gain insight in the functioning of these optically complex coastal ecosystems, a total of 23 physical, biogeochemical, and optical parameters were sampled at 63 stations during three field campaigns covering the 2012 wet and dry seasons, and the 2013 dry season. The total light absorption budget in the Van Diemen Gulf was dominated by non-algal particles (aNAP; >45% during the dry season (May–October and colored dissolved organic matter (aCDOM; 60% during the wet season (November–April. The combined absorption by aNAP and aCDOM generally exceeded ~80% of the total absorption budget from 400 to 620 nm, with phytoplankton, aPhy, accounting for <20%. In Darwin Harbour, where only the dry season conditions were sampled, the total absorption budget was dominated by an equivalent contribution of aCDOM, aNAP, and phytoplankton. The major processes explaining the seasonal variability observed in the Van Diemen Gulf are resuspension from seasonal south-easterly trade winds in combination with the tidal energy and shallow bathymetry during the dry season months, and mostly terrestrial river runoff during the monsoon which discharge terrestrial CDOM from the surrounding wetlands. Due to light-limited conditions all year round, the particulate scattering coefficient [bp(555] contributed significantly (90% to the beam attenuation coefficient c(555, thus strongly limiting phytoplankton growth (Chlorophyll a ~1 mg.m−3. Spatially, the Van Diemen Gulf had higher total suspended solids and nutrient concentrations than Darwin Harbour, with dissolved organic carbon and aCDOM subjected to photobleaching during the dry season. Key

  17. U.S. Coastal Relief Model - Florida and East Gulf of Mexico

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NGDC's U.S. Coastal Relief Model (CRM) provides the first comprehensive view of the U.S. coastal zone integrating offshore bathymetry with land topography into a...

  18. Tectonic model and seismic potential of the eastern Gulf of Alaska and Yakataga Seismic Gap

    Science.gov (United States)

    Perez, Omar J.; Jacob, Klaus H.

    1980-12-01

    Based on 13 new fault plane solutions and published seismological, geological, and geophysical data, we interpret the deformation along the Pacific-North American plate margin in the eastern Gulf of Alaska. Three major tectonic units can be distinguished: (1) the North American plate, (2) the Pacific plate, and (3) a belt of mobile borderland terranes. The Pacific plate moves in a NNW direction at rates of about 6 cm/yr in relation to the North American plate. That motion results in mostly right-lateral strike slip at the Queen Charlotte-Fairweather fault system, a well-known observation. A new finding,however, is that a small component (˜1 cm/yr) of convergence may also be present which results in minor subduction of the oceanic plate beneath portions of the continental margin. Heretofore the Queen Charlotte-Fairweather fault zone and associated continental margin was interpreted as a classical, pure transform boundary. The Yakutat block, a borderland terrane about 400 km long and 100 to 200 km wide, is carried passively by the Pacific plate except that the block slowly overrides this plate at about 1 cm/yr. This motion is taken up by almost pure thrust faulting in a southwesterly direction along a 400-km long SE striking shelf edge structure. At its NW edge the Yakutat block is in turn being thrust beneath the North American plate along the Pamplona zone-Icy Bay lineament. The underthrusting of the Yakutat block results in a major orogeny, crustal shortening and uplift of the Chugach-St. Elias range. The effects of this collision may extend as far as 500 km inland and cause some deformation at the Denali fault in the central Alaska Range. Subduction of the Pacific plate beneath the colliding margin appears responsible for development of an active volcanic arc up to 300 km inland which trends SE from the Wrangell Mountains to Yukon Territory, Canada, and perhaps to Mt. Edgecumbe volcano in southeast Alaska. The tectonic model proposed implies a high seismic

  19. Deep-sea coral and hardbottom habitats on the west Florida slope, eastern Gulf of Mexico

    Science.gov (United States)

    Ross, Steve W.; Rhode, Mike; Brooke, Sandra

    2017-02-01

    Until recently, benthic habitats dominated by deep-sea corals (DSC) appeared to be less extensive on the slope of the Gulf of Mexico (GOM) than in the northeast Atlantic Ocean or off the southeastern US. There are relatively few bioherms (i.e., coral-built mounds) in the northern GOM, and most DSCs are attached to existing hard substrata (e.g., authigenically formed carbonate). The primary structure-forming, DSC in the GOM is Lophelia pertusa, but structure is also provided by other living and dead scleractinians, antipatharians (black corals), octocorals (gorgonians, soft corals), hydrocorals and sponges, as well as abundant rocky substrata. The best development of DSCs in the GOM was previously documented within Viosca Knoll oil and gas lease blocks 826 and 862/906 (north-central GOM) and on the Campeche Bank (southern GOM in Mexican waters). This paper documents extensive deep reef ecosystems composed of DSC and rocky hard-bottom recently surveyed on the West Florida Slope (WFS, eastern GOM) during six research cruises (2008-2012). Using multibeam sonar, CTD casts, and video from underwater vehicles, we describe the physical and oceanographic characteristics of these deep reefs and provide size or area estimates of deep coral and hardground habitats. The multibeam sonar analyses revealed hundreds of mounds and ridges, some of which were subsequently surveyed using underwater vehicles. Mounds and ridges in <525 m depths were usually capped with living coral colonies, dominated by L. pertusa. An extensive rocky scarp, running roughly north-south for at least 229 km, supported lower abundances of scleractinian corals than the mounds and ridges, despite an abundance of settlement substrata. Areal comparisons suggested that the WFS may exceed other parts of the GOM slope in extent of living deep coral coverage and other deep-reef habitat (dead coral and rock). The complex WFS region warrants additional studies to better understand the influences of oceanography and

  20. The source of naturally occurring arsenic in a coastal sand aquifer of eastern Australia.

    Science.gov (United States)

    O'Shea, Bethany; Jankowski, Jerzy; Sammut, Jesmond

    2007-07-01

    The discovery of dissolved arsenic in a coastal aquifer used extensively for human consumption has led to widespread concern for its potential occurrence in other sandy coastal environments in eastern Australia. The development of an aquifer specific geomorphic model (herein) suggests that arsenic is regionally derived from erosion of arsenic-rich stibnite (Sb(2)S(3)) mineralisation present in the hinterland. Fluvial processes have transported the eroded material over time to deposit an aquifer lithology elevated in arsenic. Minor arsenic contribution to groundwater is derived from mineralised bedrock below the unconsolidated aquifer. An association with arsenic and pyrite has been observed in the aquifer in small discrete arsenian pyrite clusters rather than actual acid sulfate soil horizons. This association is likely to influence arsenic distribution in the aquifer, but is not the dominant control on arsenic occurrence. Arsenic association with marine clays is considered a function of their increased adsorptive capacity for arsenic and not solely on the influence of sea level inundation of the aquifer sediments during the Quaternary Period. These findings have implications for, but are not limited to, coastal aquifers. Rather, any aquifer containing sediments derived from mineralised provenances may be at risk of natural arsenic contamination. Groundwater resource surveys should thus incorporate a review of the aquifer source provenance when assessing the likely risk of natural arsenic occurrence in an aquifer.

  1. Policies for Reducing Coastal Risk on the East and Gulf Coasts

    Science.gov (United States)

    Glickson, D.; Johnson, S.

    2014-12-01

    Hurricane- and coastal storm-related economic losses have increased substantially over the past century, largely due to expanding population and development in susceptible coastal areas. Concurrent with this growth, the federal government has assumed an increasing proportion of the financial responsibility associated with U.S. coastal storms, which may discourage state and local governments from taking appropriate actions to reduce risk and enhance resilience. Strategies to manage coastal storm risks fall into two categories: reducing the probability of flooding or wave impact (such as seawalls, storm surge barriers, beach nourishment, dune building, restoration/expansion of oyster reefs, salt marshes, and mangroves) and reducing the number or vulnerability of people or structures (such as relocation, land-use planning, and elevating or floodproofing buildings). Over the past century, most coastal risk management programs have emphasized coastal armoring, while doing little to decrease development in harm's way. This National Research Council report calls for the development of a national vision for managing coastal risks that includes a long-term view, regional solutions, and recognition of all benefits. A national coastal risk assessment is needed to identify high priority areas. Benefit-cost analysis provides a reasonable framework to evaluate national investments in coastal risk reduction, if constrained by other important environmental, social, and life-safety factors. Extensive collaboration and additional policy changes will be necessary to move from a nation that is primarily reactive to coastal disasters to one that invests wisely in coastal risk reduction and builds resilience among coastal communities.

  2. Hydrology and pollution assessment in a coastal estuarine system. The case of the Strymonikos Gulf (North Aegean Sea

    Directory of Open Access Journals (Sweden)

    A. PAVLIDOU

    2012-12-01

    Full Text Available Three hydrographic cruises were undertaken to study the hydrology and to estimate the ecological status of the coastal ecosystem of the Strymonikos Gulf (North Aegean Sea impacted by the riverine waters of the Strymon River. Surface sediments were also collected in order to determine the levels of organic contaminants in the gulf. Three main water masses were identified in the Strymonikos Gulf throughout the year: a the surface river plume water, b the surface and subsurface Black Sea Water and c the near bottom (>50 m water of Levantine origin. High nutrient concentrations were recorded close to the mouth of the river, indicating a rather eutrophic environment, which was restricted near the river discharge. The salinity-nutrient correlations of the surface waters of the study area were linear, indicating that the riverine waters are the major source of nutrient in the gulf. DIN:P ratios varied seasonally from relatively higher values during winter and early spring to lower values in late spring-early summer. This led to a shift from likelihood P-limitation during winter and early spring to N-limitation in late spring – early summer. Total hydrocarbon concentrations measured in the sediments ranged from 19.2 to 95.9 μ g/g, whereas total polycyclic aromatic hydrocarbon (PAH values varied between 107.2 and 1019 ng/g. The application of different diagnostic criteria suggests a natural terrestrial origin for aliphatic hydrocarbons and pyrolytic origin for the PAHs. DDTs displayed the highest concentrations of all the organochlorines determined, whereas polychlorinated biphenyl (PCBs concentrations were very low. Riverine input seems to be the major source for all the compounds identified.

  3. Gulf of Mexico Coastal and Ocean Zones Strategic Assessment: Data Atlas 1985 (NODC Accession 0126646)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Atlas contains metadata and shape files of 18 different species in the Gulf of Mexico as of 1985. The shapefiles display the spatial and temporal distribution of...

  4. EAARL Coastal Topography and Imagery--Naval Live Oaks Area, Gulf Islands National Seashore, Florida, 2007

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A digital elevation map (also known as a Digital Elevation Model, or DEM) of the Naval Live Oaks Area in Florida's Gulf Islands National Seashore was produced from...

  5. National Assessment of Hurricane-Induced Coastal Erosion Hazards: Gulf of Mexico Update

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset contains information on the probabilities of hurricane-induced erosion (collision, inundation and overwash) for each 1-km section of the Gulf of Mexico...

  6. EAARL Coastal Topography and Imagery--Naval Live Oaks Area, Gulf Islands National Seashore, Florida, 2007

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A digital elevation map (also known as a Digital Elevation Model, or DEM) of the Naval Live Oaks Area in Florida's Gulf Islands National Seashore was produced from...

  7. National Assessment of Hurricane-Induced Coastal Erosion Hazards: Gulf of Mexico

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These data sets contain information on the probabilities of hurricane-induced erosion (collision, inundation and overwash) for each 1-km section of the Gulf of...

  8. AN ASSESSMENT OF THE ECOLOGICAL CONDITION OF COASTAL WATERS SURROUNDING THE GULF OF MEXICO IAPSO INTERNATIONAL ASSOCIATION FOR BIOLOGICAL OCEANOGRAPHY MEETING, LA PLATA, ARGENTINA, OCTOBER 2001

    Science.gov (United States)

    Assessment of the Ecological Condition of Coastal Waters Surrounding the Gulf of Mexico (Abstract). To be presented at the Joint IAPSO/IABO Assembly: 2001 An Ocean Odyssey, 21-26 October 2001, Mar del Plata, Argentina. 1 p. (ERL,GB R844).The purpose of the Environmental ...

  9. Investigation the Behavior of Modis Ocean Color Products Under the 2008 Red Tide in the Eastern Persian Gulf

    Science.gov (United States)

    Ghanea, M.; Moradi, M.; Kabiri, K.

    2015-12-01

    Biophysical properties of water undergo serious variations under red tide (RT) outbreak. During RT conditions, algal blooms spread out in the estuarine, marine and fresh waters due to different triggering factors such as nutrient loading, marine currents, and monsoonal winds. The Persian Gulf (PG) was a talent region subjected to different RTs in recent decade. A massive RT started from the Strait of Hormuz in October 2008 and extended towards the northern parts of the PG covering more than 1200 km of coastlines. The bloom of microorganism C. Polykrikoides was the main specie that generated large fish mortalities, and hampered marine industries, and water desalination appliances. Ocean color satellite data have many advantages to monitor and alarm RT occurrences, such as wide and continuous extent, short time of imagery, high accessibility, and appropriate estimation of ocean color parameters. Since 1999, MODerate Resolution Imaging Spectroradiometer (MODIS) satellite sensor has estimated satellite derived chlorophyll-a (Chl-a), normalized fluorescence line height (nFLH), and diffuse attenuation coefficient at 490nm (kd490). It provides a capability to study the behavior of these parameters during RT and normal conditions. This study monitors variations in satellite derived Chl-a, nFLH, and kd490 under both RT and normal conditions of the PG between 2002 and 2008. Up to now, daily and monthly variations in these products were no synchronously investigated under RT conditions in the PG. In doing so, the MODIS L1B products were provided from NASA data archive. They were corrected for Rayleigh scattering and gaseous absorption, and atmospheric interference in turbid coastal waters, and then converted to level 2 data. In addition, Enhanced Red Green Blue (ERGB) image was used to illustrate better water variations. ERGB image was built with three normalized leaving water radiance between 443 to 560nm. All the above data processes were applied by SeaDAS 7 software

  10. INVESTIGATION THE BEHAVIOR OF MODIS OCEAN COLOR PRODUCTS UNDER THE 2008 RED TIDE IN THE EASTERN PERSIAN GULF

    Directory of Open Access Journals (Sweden)

    M. Ghanea

    2015-12-01

    Full Text Available Biophysical properties of water undergo serious variations under red tide (RT outbreak. During RT conditions, algal blooms spread out in the estuarine, marine and fresh waters due to different triggering factors such as nutrient loading, marine currents, and monsoonal winds. The Persian Gulf (PG was a talent region subjected to different RTs in recent decade. A massive RT started from the Strait of Hormuz in October 2008 and extended towards the northern parts of the PG covering more than 1200 km of coastlines. The bloom of microorganism C. Polykrikoides was the main specie that generated large fish mortalities, and hampered marine industries, and water desalination appliances. Ocean color satellite data have many advantages to monitor and alarm RT occurrences, such as wide and continuous extent, short time of imagery, high accessibility, and appropriate estimation of ocean color parameters. Since 1999, MODerate Resolution Imaging Spectroradiometer (MODIS satellite sensor has estimated satellite derived chlorophyll-a (Chl-a, normalized fluorescence line height (nFLH, and diffuse attenuation coefficient at 490nm (kd490. It provides a capability to study the behavior of these parameters during RT and normal conditions. This study monitors variations in satellite derived Chl-a, nFLH, and kd490 under both RT and normal conditions of the PG between 2002 and 2008. Up to now, daily and monthly variations in these products were no synchronously investigated under RT conditions in the PG. In doing so, the MODIS L1B products were provided from NASA data archive. They were corrected for Rayleigh scattering and gaseous absorption, and atmospheric interference in turbid coastal waters, and then converted to level 2 data. In addition, Enhanced Red Green Blue (ERGB image was used to illustrate better water variations. ERGB image was built with three normalized leaving water radiance between 443 to 560nm. All the above data processes were applied by SeaDAS 7

  11. Modeled Sea Level Rise Impacts on Coastal Ecosystems at Six Major Estuaries on Florida's Gulf Coast: Implications for Adaptation Planning.

    Science.gov (United States)

    Geselbracht, Laura L; Freeman, Kathleen; Birch, Anne P; Brenner, Jorge; Gordon, Doria R

    2015-01-01

    The Sea Level Affecting Marshes Model (SLAMM) was applied at six major estuaries along Florida's Gulf Coast (Pensacola Bay, St. Andrews/Choctawhatchee Bays, Apalachicola Bay, Southern Big Bend, Tampa Bay and Charlotte Harbor) to provide quantitative and spatial information on how coastal ecosystems may change with sea level rise (SLR) and to identify how this information can be used to inform adaption planning. High resolution LiDAR-derived elevation data was utilized under three SLR scenarios: 0.7 m, 1 m and 2 m through the year 2100 and uncertainty analyses were conducted on selected input parameters at three sites. Results indicate that the extent, spatial orientation and relative composition of coastal ecosystems at the study areas may substantially change with SLR. Under the 1 m SLR scenario, total predicted impacts for all study areas indicate that coastal forest (-69,308 ha; -18%), undeveloped dry land (-28,444 ha; -2%) and tidal flat (-25,556 ha; -47%) will likely face the greatest loss in cover by the year 2100. The largest potential gains in cover were predicted for saltmarsh (+32,922 ha; +88%), transitional saltmarsh (+23,645 ha; na) and mangrove forest (+12,583 ha; +40%). The Charlotte Harbor and Tampa Bay study areas were predicted to experience the greatest net loss in coastal wetlands The uncertainty analyses revealed low to moderate changes in results when some numerical SLAMM input parameters were varied highlighting the value of collecting long-term sedimentation, accretion and erosion data to improve SLAMM precision. The changes predicted by SLAMM will affect exposure of adjacent human communities to coastal hazards and ecosystem functions potentially resulting in impacts to property values, infrastructure investment and insurance rates. The results and process presented here can be used as a guide for communities vulnerable to SLR to identify and prioritize adaptation strategies that slow and/or accommodate the changes underway.

  12. Modeled Sea Level Rise Impacts on Coastal Ecosystems at Six Major Estuaries on Florida's Gulf Coast: Implications for Adaptation Planning.

    Directory of Open Access Journals (Sweden)

    Laura L Geselbracht

    Full Text Available The Sea Level Affecting Marshes Model (SLAMM was applied at six major estuaries along Florida's Gulf Coast (Pensacola Bay, St. Andrews/Choctawhatchee Bays, Apalachicola Bay, Southern Big Bend, Tampa Bay and Charlotte Harbor to provide quantitative and spatial information on how coastal ecosystems may change with sea level rise (SLR and to identify how this information can be used to inform adaption planning. High resolution LiDAR-derived elevation data was utilized under three SLR scenarios: 0.7 m, 1 m and 2 m through the year 2100 and uncertainty analyses were conducted on selected input parameters at three sites. Results indicate that the extent, spatial orientation and relative composition of coastal ecosystems at the study areas may substantially change with SLR. Under the 1 m SLR scenario, total predicted impacts for all study areas indicate that coastal forest (-69,308 ha; -18%, undeveloped dry land (-28,444 ha; -2% and tidal flat (-25,556 ha; -47% will likely face the greatest loss in cover by the year 2100. The largest potential gains in cover were predicted for saltmarsh (+32,922 ha; +88%, transitional saltmarsh (+23,645 ha; na and mangrove forest (+12,583 ha; +40%. The Charlotte Harbor and Tampa Bay study areas were predicted to experience the greatest net loss in coastal wetlands The uncertainty analyses revealed low to moderate changes in results when some numerical SLAMM input parameters were varied highlighting the value of collecting long-term sedimentation, accretion and erosion data to improve SLAMM precision. The changes predicted by SLAMM will affect exposure of adjacent human communities to coastal hazards and ecosystem functions potentially resulting in impacts to property values, infrastructure investment and insurance rates. The results and process presented here can be used as a guide for communities vulnerable to SLR to identify and prioritize adaptation strategies that slow and/or accommodate the changes underway.

  13. Paleoclimatic and Paleoceanographic Holocene Sedimentary Records in the Gulf of California - Eastern Pacific Ocean Interhemispheric Connections

    Science.gov (United States)

    Perez-Cruz, L.; Urrutia-Fucugauchi, J.

    2009-05-01

    Initial results of a study on the distribution, thickness and stratigraphy of the sedimentary sequences in the Gulf of California are presented. The Gulf is an elongated narrow young oceanic basin bordered by the Baja California peninsula and mainland Mexico. The Gulf extends over 1200 km across the Tropic of Cancer from the tropical to the temperate zones, surrounded by arid and semi-arid regions, including the Sonora-Mojave Desert. Paleoceanographic conditions are dominated by water exchange at the Gulf mouth and water masses changes along the Gulf. Tectonic basins reach down in excess of 3000 m depths and get shallower to the north. Here we focus on the Holocene sediment sequences in the southern sector, which contains several marginal and central anoxic basins that constitute rich archives of paleoclimatic and paleoenvironmental evolution for the past 3.6 Ma. In the mouth area, main sources of sediments are silicic volcanic and intrusive rocks in the Baja peninsula and mainland, including Los Cabos and Puerto Vallarta batholiths. Fine-grained eolian dusts, pluvial and biogenic sediments are present in the sediment cores in the Gulf basins such as La Paz, Alfonso, Carmen, Pescadero and Guaymas basins. Turbiditic currents and tephra deposits also occur in the cores. Paleoclimatic records show the influences of regional processes, including the ENSO and PDO signals marked by drought and increased precipitation phases. Relative distribution and thickness of sediments at the mouth of the Gulf correlate with bathymetry and location with respect to spreading center, transform faults and margins of the peninsula and mainland Mexico. Rock magnetic core scans and mineralogy at few locations are available, which allow inferences on sediment sources, transport and deposition processes, diagenesis, paleoceanographic and paleoclimatic evolution for the Holocene.

  14. Distribution and characteristics of polycyclic aromatic hydrocarbons (PAHs) in sediments of Hadhramout coastal area, Gulf of Aden, Yemen

    Science.gov (United States)

    Mostafa, Alaa R.; Wade, Terry L.; Sweet, Stephen T.; Al-Alimi, Abdel Kawi A.; Barakat, Assem O.

    2009-08-01

    To assess the status of polycyclic aromatic hydrocarbon (PAH) contamination in sediments of Hadhramout coastal area, Gulf of Aden, Yemen, 17 surface sediment samples were collected in March-April 2005 and analyzed for PAHs with 2-6 benzene rings by gas chromatography-mass spectrometry (GC-MS). The concentrations of PAHs in surface sediments were in the range of 2.2-604 ng g - 1 (average value: 82.4 ng g - 1 ). PAHs contamination is highest in proximity to harbour activities, near Al-Dhabah petroleum terminal and urban areas. Comparison of the concentration range with a worldwide survey of sedimentary PAH concentrations ranked PAH contamination in Hadhramout coastal sediments as low to moderate. Assessment of PAH sources in Hadhramout coastal sediments suggested that they originated largely from petrogenic sources. PAHs of pyrolytic origin were found in sediments from urbanized areas. Adverse effects on benthic communities are not expected at the levels of PAHs contamination observed from harbour and industrial areas.

  15. Effects of Sewage Discharge on Trophic State and Water Quality in a Coastal Ecosystem of the Gulf of California

    Science.gov (United States)

    Vargas-González, Héctor Hugo; Arreola-Lizárraga, José Alfredo; Mendoza-Salgado, Renato Arturo; Méndez-Rodríguez, Lía Celina; Lechuga-Deveze, Carlos Hernando; Padilla-Arredondo, Gustavo; Cordoba-Matson, Miguel

    2014-01-01

    This paper provides evidence of the effects of urban wastewater discharges on the trophic state and environmental quality of a coastal water body in a semiarid subtropical region in the Gulf of California. The concentrations of dissolved inorganic nutrients and organic matter from urban wastewater primary treatment were estimated. La Salada Cove was the receiving water body and parameters measured during an annual cycle were temperature, salinity, dissolved oxygen, nitrite, nitrate, ammonia, orthophosphate, and chlorophyll a. The effects of sewage inputs were determined by using Trophic State Index (TRIX) and the Arid Zone Coastal Water Quality Index (AZCI). It was observed that urban wastewater of the city of Guaymas provided 1,237 ton N yr−1 and 811 ton P yr−1 and TRIX indicated that the receiving water body showed symptoms of eutrophication from an oligotrophic state to a mesotrophic state; AZCI also indicated that the environmental quality of the water body was poor. The effects of urban wastewater supply with insufficient treatment resulted in symptoms of eutrophication and loss of ecological functions and services of the coastal ecosystem in La Salada Cove. PMID:24711731

  16. Effects of Sewage Discharge on Trophic State and Water Quality in a Coastal Ecosystem of the Gulf of California

    Directory of Open Access Journals (Sweden)

    Héctor Hugo Vargas-González

    2014-01-01

    Full Text Available This paper provides evidence of the effects of urban wastewater discharges on the trophic state and environmental quality of a coastal water body in a semiarid subtropical region in the Gulf of California. The concentrations of dissolved inorganic nutrients and organic matter from urban wastewater primary treatment were estimated. La Salada Cove was the receiving water body and parameters measured during an annual cycle were temperature, salinity, dissolved oxygen, nitrite, nitrate, ammonia, orthophosphate, and chlorophyll a. The effects of sewage inputs were determined by using Trophic State Index (TRIX and the Arid Zone Coastal Water Quality Index (AZCI. It was observed that urban wastewater of the city of Guaymas provided 1,237 ton N yr−1 and 811 ton P yr−1 and TRIX indicated that the receiving water body showed symptoms of eutrophication from an oligotrophic state to a mesotrophic state; AZCI also indicated that the environmental quality of the water body was poor. The effects of urban wastewater supply with insufficient treatment resulted in symptoms of eutrophication and loss of ecological functions and services of the coastal ecosystem in La Salada Cove.

  17. The use of current-induced transport for coastal protection in the Gulf of Finland, the Baltic Sea

    Science.gov (United States)

    Soomere, Tarmo; Delpeche, Nicole; Viikmäe, Bert

    2010-05-01

    The existence of semi-persistent patterns of currents in various parts of the Baltic Sea leads to the interplay of the high variability of the surface currents with the presence of rapid pathways of the transport of adverse impacts. This variability and accompanying asymmetry of the current-driven transport opens a new way towards the use of marine dynamics for reducing the environmental risks. The key benefit is an increase of time during which an adverse impact (for example, an oil spill) reaches a vulnerable area after an accident has happened. We attempt to identify the regions that are at high and low risk in terms of current-transported coastal pollution in the Gulf of Finland, the Baltic Sea. A solution to this inverse problem is sought by means of analysis of a large pool of solutions to an associated direct problem of the current-driven transport. The basic tool is a Lagrangian trajectory model, TRACMASS that uses 3D current velocity fields calculated by the Rossby Centre global circulation model. The goal is to evaluate the basic parameters of transport that cannot be extracted directly from the velocity data, such as the average net transport rate and the ratio of average net and bulk transport. These parameters allow estimating whether or not the proposed approach would lead to substantial benefit. Trajectories of current-driven pollution for each sea point are simulated for a few weeks and the simulations are repeated over several years. The average time it takes for the pollutants to reach the coastal zone is a measure of risk associated with the starting point. A comparison of the average net transport with the velocity fields allows identifying the areas that may have very strong (or weak) flow and the direction of such flows. Similar patterns in the ratio of average net and bulk transport allows identifying both the areas of fast moving flow and the areas where mostly local eddy-driven circulation exists. The results show a substantial seasonal and

  18. Multi-temporal retreat rates along the eastern Mediterranean coastal cliff

    Science.gov (United States)

    Katz, O.; Mushkin, A.

    2012-12-01

    The Israeli coastal cliff extends about 50 km along the eastern Mediterranean shores. The cliff is comprised of late Quaternary eolianites and paleosols and reaches heights of up to 50 meters. In places, time-averaged inland cliff-top retreat rates of up to a few tens of centimeters per year have been measured usually by comparing aerial photos from the last decades. Commonly, these locally constrained retreat rates have been: 1) extrapolated as representative of the entire cliff length, and 2) adopted by hazard-mitigation and planning authorities. Here, we re-evaluate the current understanding of coastal-retreat patterns and rates along Israel's Mediterranean cliff line using a suite of field observations, aerial photography and recently obtained airborne and ground based high resolution LiDAR measurement of cliff morphologies. First, we constrain the decadal-scale retreat rates along the coastal-cliff by comparing the cliff-top location in 1945 and 2004 using aerial photos. We find a statistically significant spatial correlation between: 1) calculated low retreat rates (less than 0.1 m/yr) and field-based criteria indicating overall stability: slope angle of 45 deg. and talus cover along the lower part of the cliff and developed vegetation cover, and 2) high retreat rates and field criteria indicating recent instability: fresh landslide scars and 'hanging' valleys, which provides independent support for the calculated retreat rates. Calculated 60 years average cliff-top retreat rates of less than 0.1, 0.2 and 0.3 m/yr along 58%, 77% and 85% of the cliff length, respectively, reveal that extended stretches of the cliff line did not experience detectable retreat in the past 60 years, thus implying relative stability of 50% of Israel's costal cliffs during this time period. Second, we constrain the annual retreat rates using repeat high-resolution ground based LiDAR surveys before and after an extreme winter storm that occurred in Dec. 2010. Locally, storm induced

  19. Characterization of geomorphic units in the alluvial valleys and channels of Gulf Coastal Plain rivers in Texas, with examples from the Brazos, Sabine, and Trinity Rivers, 2010

    Science.gov (United States)

    Coffman, David K.; Malstaff, Greg; Heitmuller, Franklin T.

    2011-01-01

    The U.S. Geological Survey, in cooperation with the Texas Water Development Board, described and characterized examples of geomorphic units within the channels and alluvial valleys of Texas Gulf Coastal Plain rivers using a geomorphic unit classification scale that differentiates geomorphic units on the basis of their location either outside or inside the river channel. The geomorphic properties of a river system determine the distribution and type of potential habitat both within and adjacent to the channel. This report characterizes the geomorphic units contained in the river channels and alluvial valleys of Texas Gulf Coastal Plain rivers in the context of the River Styles framework. This report is intended to help Texas Instream Flow Program practitioners, river managers, ecologists and biologists, and others interested in the geomorphology and the physical processes of the rivers of the Texas Gulf Coastal Plain (1) gain insights into how geomorphic units develop and adjust spatially and temporally, and (2) be able to recognize common geomorphic units from the examples cataloged in this report. Recent aerial imagery (high-resolution digital orthoimagery) collected in 2008 and 2009 were inspected by using geographic information system software to identify representative examples of the types of geomorphic units that occurred in the study area. Geomorphic units outside the channels of Texas Gulf Coastal Plain rivers are called \\"valley geomorphic units\\" in this report. Valley geomorphic units for the Texas Gulf Coastal Plain rivers described in this report are terraces, flood plains, crevasses and crevasse splays, flood-plain depressions, tie channels, tributaries, paleochannels, anabranches, distributaries, natural levees, neck cutoffs, oxbow lakes, and constructed channels. Channel geomorphic units occur in the river channel and are subject to frequent stresses associated with flowing water and sediment transport; they adjust (change) relatively quickly in

  20. Past permafrost on the Mid-Atlantic coastal plain, eastern United States

    Science.gov (United States)

    French, H.; Demitroff, M.; Newell, W.L.

    2009-01-01

    Sand-wedge casts, soil wedges and other non-diastrophic, post-depositional sedimentary structures suggest that Late-Pleistocene permafrost and deep seasonal frost on the Mid-Atlantic Coastal Plain extended at least as far south as southern Delaware, the Eastern Shore and southern Maryland. Heterogeneous cold-climate slope deposits mantle lower valley-side slopes in central Maryland. A widespread pre-existing fragipan is congruent with the inferred palaeo-permafrost table. The high bulk density of the fragipan was probably enhanced by either thaw consolidation when icy permafrost degraded at the active layer-permafrost interface or by liquefaction and compaction when deep seasonal frost thawed. ?? 2009 John Wiley & Sons, Ltd.

  1. Evaluation of regional energy security in eastern coastal China based on the DPSIR model

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yan; SHEN Lei

    2012-01-01

    The DPSIR assessment method,which implies the relationships among driving force (D),pressure (P),status (S),impact (I),and response (R),is widely applied by scholars.This paper aims to establish a comprehensive assessment system for regional energy security in eastern coastal China based on the above model using different indicators.Factor analysis and the SPSS statistical analysis software were used to carry out scientific and quantitative assessments.The results indicated that contradictions of energy supply and demand as well as environmental pollution are the critical factors that present great challenges to regional energy security in this area.The authors argued that a sustainable,stable,and safe supply energy supply is crucial in solving the aforesaid dilemma,and improving the energy use efficiency is one of the best choices.Some countermeasures and suggestions regarding regional energy supply stability and utilization security were pointed out.

  2. Remote-sensing observations of coastal sub-mesoscale eddies in the south-eastern Baltic

    Directory of Open Access Journals (Sweden)

    Evgenia Gurova

    2012-11-01

    Full Text Available This paper presents an overview of the sub-mesoscale eddies observed in the coastalzone of the south-eastern Baltic near the shores of the Sambian Peninsula and theCuronian Spit based on CODAR (high-frequency coast-based radar measurementsand analysis of MODIS and ASAR satellite images for the period 30 March2000-31 December 2011. It was found that when winds are predominantly SW, S or W,a wake eddy of varying size (up to 25 km in diameter forms off Cape Taran andcan cover the area between the shoreline and the 65 m isobath. Its longestlifetime, observed using MODIS images, was 6 days. Another location wherecoastal sub-mesoscale eddies (up to 10-15 km in diameter of varying formregularly appear is the coastal slope near the southern and central part ofthe Curonian Spit.

  3. High abundance of salps in the coastal Gulf of Alaska during 2011: A first record of bloom occurrence for the northern Gulf

    Science.gov (United States)

    Li, Kaizhi; Doubleday, Ayla J.; Galbraith, Moira D.; Hopcroft, Russell R.

    2016-10-01

    Atypical high abundances of two salp species occurred in the coastal Gulf of Alaska during 2011. Salpa aspera dominated numerically in aggregate form during spring, and became uncommon during summer, while Cyclosalpa bakeri increased from low during spring to high abundance during summer. Both species were absent, or nearly so, by fall. C. bakeri abundance was positively correlated to surface temperature in spring and summer, and both species abundances were negatively correlated to chlorophyll a. The proportion of aggregate forms of both species was higher than that of solitary forms during spring and summer. The length-frequency of S. aspera aggregate individuals ranged primarily from 10 to 50 mm, and solitary forms reached 130 mm, while C. bakeri aggregates were 10-25 mm, with solitary forms up to 75 mm. Estimated biomass of S. aspera was 0.35±0.64 mg C m-3 in southeastern Alaska during spring then decreased to 0.03±0.12 mg C m-3 during summer. Estimated biomass of C. bakeri was 0.03±0.06 mg C m-3 over the entire sampling domain during spring, then rose to 0.15±0.25 mg C m-3 during summer. The volume of water filtered daily by S. aspera was estimated to be up to 17% of the 200 m water column at some stations during spring, but only up to ~3.5% during summer. Substantially higher grazing impact was possible if animals were largely confined to the surface mixed layer (typically 20-30 m thick). The average volume filtrated was higher during spring for S. aspera, but for C. bakeri it was higher during summer. We propose that the combined effect of the northward transport of seed populations, their rapid biomass increase through asexual reproduction, and the high clearance rate of salps contributed to atypically low chlorophyll a in the Gulf of Alaska during spring and summer of 2011. This unusual event impacted ecosystem function during 2011, and might be expected to increase in frequency as the Gulf continues to respond to climate variations.

  4. Spatio-Temporal Characteristics of Rural Economic Development in Eastern Coastal China

    Directory of Open Access Journals (Sweden)

    Guogang Wang

    2015-01-01

    Full Text Available Although the regional differences of rural economic development can be easily determined, a challenging problem for research studies regarding rural economic development has been the inter-relatedness between different areas, and this challenge has been noted remarkably little in research data to date. As an empirical investigation, this study analyzes the spatio-temporal characteristics of rural economic development from a period beginning in 1978 to the year 2012, in the eastern coastal region of China. In order to determine the special differentiation characteristics of rural economic development, three indexes, namely the Gini coefficient (G, Tsui–Wang index (TW and Theil index (T, were employed. To explore the inter-relatedness among the different areas, we selected a spatial autocorrelation model. The results indicated that, to a large extent, rural economic development from 1978 to 2012 in the eastern coastal region of China was greatly influenced, and the per capita annual net income changed significantly, due to the process of rapid urbanization and industrialization. Generally speaking, the annual net income constantly increased, from 87.7 USD in 1978 to 1628.1 USD in 2012. However, the calculation results indicated that the per capita income gap in the same province decreased, while the gap between the provinces presented an aggregate trend. The regional polarization widened continuously. It was also found that the spatial positive autocorrelation for the regional economy was significant, with a waving and ascending trend, and the neighbor effect of regional economic growth was continuously strengthened. Qualitative analysis of the driving mechanism was applied, and it was determined that there are three primary factors affecting the development of the rural regions, namely resource endowments, economic location and policies.

  5. Biogeography of Anurans from the Poorly Known and Threatened Coastal Sandplains of Eastern Brazil

    Science.gov (United States)

    Xavier, Ariane Lima; Guedes, Thaís Barreto; Napoli, Marcelo Felgueiras

    2015-01-01

    The east coast of Brazil comprises an extensive area inserted in the Tropical Atlantic Domain and is represented by sandy plains of beach ridges commonly known as Restingas. The coastal environments are unique and house a rich amphibian fauna, the geographical distribution patterns of which are incipient. Biogeographical studies can explain the current distributional patterns and provide the identification of natural biogeographical units. These areas are important in elucidating the evolutionary history of the taxa and the areas where they occur. The aim of this study was to seek natural biogeographical units in the Brazilian sandy plains of beach ridges by means of distribution data of amphibians and to test the main predictions of the vicariance model to explain the patterns found. We revised and georeferenced data on the geographical distribution of 63 anuran species. We performed a search for latitudinal distribution patterns along the sandy coastal plains of Brazil using the non-metric multidimensional scaling method (NMDS) and the biotic element analysis to identify natural biogeographical units. The results showed a monotonic variation in anuran species composition along the latitudinal gradient with a break in the clinal pattern from 23°S to 25°S latitude (states of Rio de Janeiro to São Paulo). The major predictions of the vicariance model were corroborated by the detection of four biotic elements with significantly clustered distribution and by the presence of congeneric species distributed in distinct biotic elements. The results support the hypothesis that vicariance could be one of the factors responsible for the distribution patterns of the anuran communities along the sandy coastal plains of eastern Brazil. The results of the clusters are also congruent with the predictions of paleoclimatic models made for the Last Glacial Maximum of the Pleistocene, such as the presence of historical forest refugia and biogeographical patterns already detected

  6. Carbon Sequestration in Wetland Soils of the Northern Gulf of Mexico Coastal Region

    Science.gov (United States)

    Coastal wetlands play an important but complex role in the global carbon cycle, contributing to the ecosystem service of greenhouse gas regulation through carbon sequestration. Although coastal wetlands occupy a small percent of the total US land area, their potential for carbon...

  7. Multidisciplinary oil spill modeling to protect coastal communities and the environment of the Eastern Mediterranean Sea

    Science.gov (United States)

    Alves, Tiago M.; Kokinou, Eleni; Zodiatis, George; Radhakrishnan, Hari; Panagiotakis, Costas; Lardner, Robin

    2016-11-01

    We present new mathematical and geological models to assist civil protection authorities in the mitigation of potential oil spill accidents in the Eastern Mediterranean Sea. Oil spill simulations for 19 existing offshore wells were carried out based on novel and high resolution bathymetric, meteorological, oceanographic, and geomorphological data. The simulations show a trend for east and northeast movement of oil spills into the Levantine Basin, affecting the coastal areas of Israel, Lebanon and Syria. Oil slicks will reach the coast in 1 to 20 days, driven by the action of the winds, currents and waves. By applying a qualitative analysis, seabed morphology is for the first time related to the direction of the oil slick expansion, as it is able to alter the movement of sea currents. Specifically, the direction of the major axis of the oil spills, in most of the cases examined, is oriented according to the prevailing azimuth of bathymetric features. This work suggests that oil spills in the Eastern Mediterranean Sea should be mitigated in the very few hours after their onset, and before wind and currents disperse them. We explain that protocols should be prioritized between neighboring countries to mitigate any oil spills.

  8. Multidisciplinary oil spill modeling to protect coastal communities and the environment of the Eastern Mediterranean Sea.

    Science.gov (United States)

    Alves, Tiago M; Kokinou, Eleni; Zodiatis, George; Radhakrishnan, Hari; Panagiotakis, Costas; Lardner, Robin

    2016-11-10

    We present new mathematical and geological models to assist civil protection authorities in the mitigation of potential oil spill accidents in the Eastern Mediterranean Sea. Oil spill simulations for 19 existing offshore wells were carried out based on novel and high resolution bathymetric, meteorological, oceanographic, and geomorphological data. The simulations show a trend for east and northeast movement of oil spills into the Levantine Basin, affecting the coastal areas of Israel, Lebanon and Syria. Oil slicks will reach the coast in 1 to 20 days, driven by the action of the winds, currents and waves. By applying a qualitative analysis, seabed morphology is for the first time related to the direction of the oil slick expansion, as it is able to alter the movement of sea currents. Specifically, the direction of the major axis of the oil spills, in most of the cases examined, is oriented according to the prevailing azimuth of bathymetric features. This work suggests that oil spills in the Eastern Mediterranean Sea should be mitigated in the very few hours after their onset, and before wind and currents disperse them. We explain that protocols should be prioritized between neighboring countries to mitigate any oil spills.

  9. Biomarker responses in mudskipper (Periophthalmus waltoni) from the coastal areas of the Persian Gulf with oil pollution.

    Science.gov (United States)

    Shirani, Mehrnoosh; Mirvaghefi, Alireza; Farahmand, Hamid; Abdollahi, Mohammad

    2012-11-01

    A suite of 5 different biomarker responses were selected and measured in 3 different phases of detoxification process in mudskipper Periophthalmus waltoni from 3 different stations including Soltani Inlet, Shif Island and Ameri Port in Bushehr coastal area of the Persian Gulf. The selected biomarkers were 7-ethoxyresorufin O-deethylase (EROD), glutathione S-transferase (GST), biliary fluorescent aromatic compounds (FACs), DNA damage using the Comet assay and micronucleus (MN). Spatial variations in biomarker responses were observed in different sites. EROD, GST, FACs, DNA damage and MN were significantly elevated in mudskippers in the most oil impacted site (Soltani inlet). Based on the assessments, bile metabolites, EROD and GST induction appear to be sensitive to polycyclic aromatic hydrocarbons (PAHs) and can be considered as complementary biomarkers; therefore P. waltoni has the potential to be used as a bioindicator in these types of ecosystems.

  10. Diurnal and seasonal trends in carbonyl levels in a semi-urban coastal site in the Gulf of Campeche, Mexico

    Science.gov (United States)

    Cerón, R. M.; Cerón, J. G.; Muriel, M.

    Concentrations of formaldehyde, acetaldehyde, acetone, propionaldehyde and butyraldehyde were measured in a semi-urban coastal site in the Gulf of Campeche, Mexico, during the winter, summer and autumn seasons. Measurements were carried out from 10 February 2004 to 16 November 2004. Carbonyl compound levels showed pronounced diurnal and seasonal variations. Maximum concentrations occurred between 13:00 h and 16:00 h, when vehicular traffic and photochemical activity were intense, and during the summer (when there was greater solar radiation). Only acetone during the first campaign (winter) did not correlate with temperature; it showed an inverse diurnal pattern, with higher concentrations during the night, probably due to a local and temporal source. The low concentrations of the main carbonyls found in this study, compared with the values reported for other urban areas, seem to indicate that air quality is still satisfactory in Carmen City.

  11. Knowledge, Information, and Views of Climate Change: An Examination of Coastal Stakeholders along the Gulf of Mexico

    Directory of Open Access Journals (Sweden)

    James W. Stoutenborough

    2015-11-01

    Full Text Available The ability to understand complex issues is essential to adequately evaluate risk and policy alternatives. Stakeholders are more likely to understand and influence these issues. While stakeholders that specialize in coastal regions have many issues that demand their attention, there are a few that potentially affect everyone within this community. We utilize in-depth interviews to examine climate change attitudes, and the influence of knowledge, information, and institutions within a sample of stakeholders along the Gulf Coast in Florida, Texas, and Louisiana. Our analysis is the first to reveal that institutional forces may influence climate change attitudes for members of that institution. Furthermore, we learn that different sources of information directly influence these attitudes.

  12. Final Project Closeout Report for Sprint Hydrogen Fuel Cell (HFC) Deployment Project in California, Gulf Coast and Eastern Seaboard Markets

    Energy Technology Data Exchange (ETDEWEB)

    Kenny, Kevin [Sprint, Reston, VA (United States); Bradley, Dwayne [Burns & McDonnell, Kansas City, MO (United States)

    2015-09-01

    Sprint is one of the telecommunications industry leaders in the deployment of hydrogen fuel cell (HFC) systems to provide backup power for their mission critical wireless network facilities. With several hundred fuel cells commissioned in California, states in the gulf coast region, and along the upper eastern seaboard. A strong incentive for advancing the integration of fuel cells into the Sprint network came through the award of a Department of Energy (DOE) grant focused on Market Transformation activities for project (EE0000486). This grant was funded by the 2009 American Recovery and Reinvestment Act (ARRA). The funding provided by DOE ($7.295M) was allocated to support the installation of 260 new HFC systems, equipped with an on-site refillable Medium Pressure Hydrogen Storage Solution (MPHSS), as well as for the conversion of 21 low pressure hydrogen systems to the MPHSS, in hopes of reducing barriers to market acceptance.

  13. The polycyclic aromatic hydrocarbon degradation potential of Gulf of Mexico coastal microbial communities after the Deepwater Horizon oil spill

    Directory of Open Access Journals (Sweden)

    Anthony D. Kappell

    2014-05-01

    Full Text Available The Deepwater Horizon (DWH blowout resulted in oil transport, including polycyclic aromatic hydrocarbons (PAHs to the Gulf of Mexico shoreline. The microbial communities of these shorelines are thought to be responsible for the intrinsic degradation of PAHs. To investigate the Gulf Coast beach microbial community response to hydrocarbon exposure, we examined the functional gene diversity, bacterial community composition, and PAH degradation capacity of a heavily oiled and non-oiled beach following the oil exposure. With a non-expression functional gene microarray targeting 539 gene families, we detected 28,748 coding sequences. Of these sequences, 10% were uniquely associated with the severely oil-contaminated beach and 6.0% with the non-oiled beach. There was little variation in the functional genes detected between the two beaches; however the relative abundance of functional genes involved in oil degradation pathways, including PAHs, were greater in the oiled beach. The microbial PAH degradation potentials of both beaches, were tested in mesocosms. Mesocosms were constructed in glass columns using sands with native microbial communities, circulated with artificial sea water and challenged with a mixture of PAHs. The low-molecular weight PAHs, fluorene and naphthalene, showed rapid depletion in all mesocosms while the high-molecular weight benzo[α]pyrene was not degraded by either microbial community. Both the heavily oiled and the non-impacted coastal communities showed little variation in their biodegradation ability for low molecular weight PAHs. Massively-parallel sequencing of 16S rRNA genes from mesocosm DNA showed that known PAH degraders and genera frequently associated with oil hydrocarbon degradation represented a major portion of the bacterial community. The observed similar response by microbial communities from beaches with a different recent history of oil exposure suggests that Gulf Coast beach communities are primed for PAH

  14. The polycyclic aromatic hydrocarbon degradation potential of Gulf of Mexico native coastal microbial communities after the Deepwater Horizon oil spill.

    Science.gov (United States)

    Kappell, Anthony D; Wei, Yin; Newton, Ryan J; Van Nostrand, Joy D; Zhou, Jizhong; McLellan, Sandra L; Hristova, Krassimira R

    2014-01-01

    The Deepwater Horizon (DWH) blowout resulted in oil transport, including polycyclic aromatic hydrocarbons (PAHs) to the Gulf of Mexico shoreline. The microbial communities of these shorelines are thought to be responsible for the intrinsic degradation of PAHs. To investigate the Gulf Coast beach microbial community response to hydrocarbon exposure, we examined the functional gene diversity, bacterial community composition, and PAH degradation capacity of a heavily oiled and non-oiled beach following the oil exposure. With a non-expression functional gene microarray targeting 539 gene families, we detected 28,748 coding sequences. Of these sequences, 10% were uniquely associated with the severely oil-contaminated beach and 6.0% with the non-oiled beach. There was little variation in the functional genes detected between the two beaches; however the relative abundance of functional genes involved in oil degradation pathways, including polycyclic aromatic hydrocarbons (PAHs), were greater in the oiled beach. The microbial PAH degradation potentials of both beaches, were tested in mesocosms. Mesocosms were constructed in glass columns using sands with native microbial communities, circulated with artificial sea water and challenged with a mixture of PAHs. The low-molecular weight PAHs, fluorene and naphthalene, showed rapid depletion in all mesocosms while the high-molecular weight benzo[α]pyrene was not degraded by either microbial community. Both the heavily oiled and the non-impacted coastal communities showed little variation in their biodegradation ability for low molecular weight PAHs. Massively-parallel sequencing of 16S rRNA genes from mesocosm DNA showed that known PAH degraders and genera frequently associated with oil hydrocarbon degradation represented a major portion of the bacterial community. The observed similar response by microbial communities from beaches with a different recent history of oil exposure suggests that Gulf Coast beach communities are

  15. Persistent organic pollutants (POPs) in populations of the clam Chione californiensis in coastal lagoons of the Gulf of California.

    Science.gov (United States)

    Vargas-González, Héctor H; Méndez-Rodríguez, Lía C; García-Hernández, Jaqueline; Mendoza-Salgado, Renato A; Zenteno-Savín, Tania; Arreola-Lizárraga, José A

    2016-07-02

    This study examines the potential public health risk due to the massive use of organochlorine pesticides (OCs) in agriculture in the Gulf of California. Specimens of the clam Chione californiensis were collected from three coastal lagoons (Yavaros, Altata and Reforma). Sites were classified as polluted/nonpolluted based on the presence/absence of OCs as an indicator of the persistence of these pollutants; in polluted sites, the time elapsed since pesticide application (past or recent) was estimated. Screening values (SV) for protecting human health as per the U.S. Environmental Protection Agency (EPA) were used for risk assessment. OCs detected were ranked according to frequency of occurrence as follows: γ-chlordane (75%) > endrin (54%) > aldrin (48%) > heptachlor, and dichlorodiphenyl-trichloroethane (DDE) (37%) > β-heptachlor epoxide (30%) > lindane (α-BHC, δ-BHC) and endosulphan I (≤ 6%). Specifically, OCs detected at the highest concentration were heptachlor in Yavaros (0.0168 µgg(-1)) and Altata (0.0046 µgg(-1)), and aldrin in Reforma (0.0019 µgg(-1)). β-Heptachlor epoxide in Altata and Reforma was the only OC with a concentration exceeding the EPA Screening Value. From our results and based on the monthly consumption limit set forth by EPA, the maximum safe consumption of clams to avoid a carcinogenic risk derived from β-heptachlor epoxide in the fishing villages of Yavaros and Altata is 4 servings per month (1 serving = 0.227 kg) by a 70-kg person. These findings suggest that concentrations of OCs and their isomers in C. californiensis populations reflect environmental persistence as well as recent inputs of OCs into coastal lagoons in the Gulf of California.

  16. Climate projections of spatial variations in coastal storm surges along the Gulf of Mexico and U.S. east coast

    Science.gov (United States)

    Yao, Zhigang; Xue, Zuo; He, Ruoying; Bao, Xianwen; Xie, Jun; Ge, Qian

    2017-02-01

    Using statistically downscaled atmospheric forcing, we performed a numerical investigation to evaluate future climate's impact on storm surges along the Gulf of Mexico and U.S. east coast. The focus is on the impact of climatic changes in wind pattern and surface pressure while neglecting sea level rise and other factors. We adapted the regional ocean model system (ROMS) to the study region with a mesh grid size of 7-10 km in horizontal and 18 vertical layers. The model was validated by a hindcast of the coastal sea levels in the winter of 2008. Model's robustness was confirmed by the good agreement between model-simulated and observed sea levels at 37 tidal gages. Two 10-year forecasts, one for the IPCC Pre-Industry (PI) and the other for the A1FI scenario, were conducted. The differences in model-simulated surge heights under the two climate scenarios were analyzed. We identified three types of responses in extreme surge heights to future climate: a clear decrease in Middle Atlantic Bight, an increase in the western Gulf of Mexico, and non-significant response for the remaining area. Such spatial pattern is also consistent with previous projections of sea surface winds and ocean wave heights.

  17. A new genus and species of cyclopoid (Crustacea, Copepoda, Cyclopinidae) from a coastal system in the Gulf of Mexico

    Science.gov (United States)

    Suárez-Morales, Eduardo; Almeyda-Artigas, Roberto Javier

    2015-01-01

    Abstract A new, monotypic genus of the interstitial marine cyclopoid copepod family Cyclopinidae G.O. Sars, 1913 is described from male and female specimens collected at Laguna de Términos, a large coastal lagoon system in the southern Gulf of Mexico. Mexiclopina campechana gen. et sp. n. cannot be adequately placed in any extant genus within the family. It differs from other cyclopinid genera in having a unique combination of characters including: 1) absence of modified brush-like seta on the mandibular exopod; 2) maxillule exopod with stout setal elements and brush-like setae absent; 3) basis of mandible with one seta; 4) presence of a modified seta on endopod of fourth leg; 5) fifth leg exopod unsegmented, armed with three elements in the female and five in the male; 6) intercoxal sclerite of first swimming leg with two medial spiniform processes on distal margin. The new genus is monotypic and appears to be most closely related to Cyclopina Claus, 1863 and Heptnerina Ivanenko & Defaye, 2004; the new species was compared with species of Cyclopina and it resembles Cyclopina americana Herbst, 1982 and Cyclopina caissara Lotufo, 1994. This is the second record of a species of Cyclopinidae in Mexico and the first in the Gulf of Mexico; the number of cyclopinid species recorded from the Americas is now 13. PMID:26668545

  18. UV filters are an environmental threat in the Gulf of Mexico: a case study of Texas coastal zones

    Directory of Open Access Journals (Sweden)

    Hamidreza Sharifan

    2016-10-01

    Full Text Available UV filters are the main ingredients in many cosmetics and personal care products. A significant amount of lipophilic UV filters annually enters the surface water due to large numbers of swimmers and sunbathers. The nature of these compounds cause bioaccumulation in commercial fish, particularly in estuarine areas. Consequently, biomagnification in the food chain will occur. This study estimated the amount of four common UV filters (ethylhexyl methoxycinnamate, EHMC; octocrylene, OC; butyl methoxydibenzoylmethane, BM-DBM; and benzophenone-3, BP3, which may enter surface water in the Gulf of Mexico. Our data analysis was based on the available research data and EPA standards (age classification/human body parts. The results indicated that among the 14 counties in Texas coastal zones, Nueces, with 43 beaches, has a high potential of water contamination through UV filters; EHMC: 477 kg year−1; OC: 318 kg year−1; BM-DBM: 258 kg year−1; and BP by 159 kg year−1. Refugio County, with a minimum number of beaches, indicated the lowest potential of UV filter contamination. The sensitive estuarine areas of Galveston receive a significant amount of UV filters. This article suggests action for protecting Texas estuarine areas and controlling the number of tourists and ecotourism that occurs in sensitive areas of the Gulf of Mexico.

  19. A new genus and species of cyclopoid (Crustacea, Copepoda, Cyclopinidae) from a coastal system in the Gulf of Mexico.

    Science.gov (United States)

    Suárez-Morales, Eduardo; Almeyda-Artigas, Roberto Javier

    2015-01-01

    A new, monotypic genus of the interstitial marine cyclopoid copepod family Cyclopinidae G.O. Sars, 1913 is described from male and female specimens collected at Laguna de Términos, a large coastal lagoon system in the southern Gulf of Mexico. Mexiclopina campechana gen. et sp. n. cannot be adequately placed in any extant genus within the family. It differs from other cyclopinid genera in having a unique combination of characters including: 1) absence of modified brush-like seta on the mandibular exopod; 2) maxillule exopod with stout setal elements and brush-like setae absent; 3) basis of mandible with one seta; 4) presence of a modified seta on endopod of fourth leg; 5) fifth leg exopod unsegmented, armed with three elements in the female and five in the male; 6) intercoxal sclerite of first swimming leg with two medial spiniform processes on distal margin. The new genus is monotypic and appears to be most closely related to Cyclopina Claus, 1863 and Heptnerina Ivanenko & Defaye, 2004; the new species was compared with species of Cyclopina and it resembles Cyclopina americana Herbst, 1982 and Cyclopina caissara Lotufo, 1994. This is the second record of a species of Cyclopinidae in Mexico and the first in the Gulf of Mexico; the number of cyclopinid species recorded from the Americas is now 13.

  20. Measurements of biochemical markers of pollution in mussels Mytilus galloprovincialis from coastal areas of the Saronikos Gulf (Greece

    Directory of Open Access Journals (Sweden)

    C. TSANGARIS

    2012-12-01

    Full Text Available Alterations in a number of biochemical parameters in marine organisms represent specific markers of exposure to particular classes of contaminants. They are used as tools for the detection and monitoring of pollution. In this study, two biochemical markers of pollution, metallothionein (MT content and acetylcholinesterase (AChE activity were measured in indigenous and transplanted mussels Mytilus galloprovincialis from coastal areas within the Saronikos Gulf subject to high anthropogenic activities. Biannual measurements of the two biomarkers in indigenous mussel populations for two years revealed no significant differences among stations representing a pollution gradient. Limited differences in MT levels were only found between mussel populations transplanted at lesser and more impacted stations. Both biomarkers showed a variation with respect to the season of sampling, whilst during the second year of measurements a concomitant increase in metallothionein content with a decrease in acetylcholinesterase activity was noted. Our results indicate that the applied biochemical markers in indigenous mussel populations do not reflect the type of pollution in the Saronikos Gulf to a degree that can be used for pollution monitoring in the area.

  1. Introduction to the special issue on “Understanding and predicting change in the coastal ecosystems of the northern Gulf of Mexico”

    Science.gov (United States)

    Brock, John C.; Barras, John A.; Williams, S. Jeffress

    2013-01-01

    The coastal region of the northern Gulf of Mexico owes its current landscape structure to an array of tectonic, erosional and depositional, climatic, geochemical, hydrological, ecological, and human processes that have resulted in some of the world's most complex, dynamic, productive, and threatened ecosystems. Catastrophic hurricane landfalls, ongoing subsidence and erosion exacerbated by sea-level rise, disintegration of barrier island chains, and high rates of wetland loss have called attention to the vulnerability of northern Gulf coast ecosystems, habitats, built infrastructure, and economy to natural and anthropogenic threats. The devastating hurricanes of 2005 (Katrina and Rita) motivated the U.S. Geological Survey Coastal and Marine Geology Program and partnering researchers to pursue studies aimed at understanding and predicting landscape change and the associated storm hazard vulnerability of northern Gulf coast region ecosystems and human communities. Attaining this science goal requires increased knowledge of landscape evolution on geologic, historical, and human time scales, and analysis of the implications of such changes in the natural and built components of the landscape for hurricane impact susceptibility. This Special Issue of the Journal of Coastal Research communicates northern Gulf of Mexico research results that (1) improve knowledge of prior climates and depositional environments, (2) assess broad regional ecosystem structure and change over Holocene to human time scales, (3) undertake process studies and change analyses of dynamic landscape components, and (4) integrate framework, climate, variable time and spatial scale mapping, monitoring, and discipline-specific process investigations within interdisciplinary studies.

  2. Climatically-controlled siliceous productivity in the eastern Gulf of Guinea during the last 40 000 yr

    Directory of Open Access Journals (Sweden)

    X. Crosta

    2012-03-01

    Full Text Available Opal content and diatom assemblages were analysed in core GeoB4905-4 to reconstruct siliceous productivity changes in the eastern Gulf of Guinea during the last 40 000 yr. Opal and total diatom accumulation rates presented low values over the considered period, except during the Last Glacial Maximum and between 15 000 calendar years Before Present (15 cal. ka BP and 5.5 cal. ka BP, the so-called African Humid Period, when accumulation rates of brackish and freshwater diatoms at the core site were highest. Conversely, accumulation rates of windblown diatoms exhibited an opposite pattern with higher values before and after the African Humid Period and greatest values during Heinrich Events, the Younger Dryas and since 5.5 cal. ka BP.

    Our results demonstrate that siliceous productivity in the eastern Gulf of Guinea was directly driven by the nutrient load from local rivers, whose discharges were forced by precipitation changes over western Equatorial Africa and/or modification of the fluvio-deltaic systems forced by sea level changes. Precipitation in this region is controlled by the West African monsoon which is, in turn, partly dependent on the presence and intensity of the Atlantic Cold Tongue (ACT. Our results therefore suggest that the ACT was weakened, warmer trade winds were less vigorous, and cloud convection and precipitation were greater during the AHP though centennial-to-millennial timescale dry events were observed at ∼10 cal. ka BP, ∼8.5 cal. ka BP and ∼6 cal. ka BP. Conversely, the ACT was more intense, trade winds were more vigorous and African climate was more arid during H1, the Younger Dryas and after 5.5 cal. ka BP into the present.

  3. Climatically-controlled siliceous productivity in the eastern Gulf of Guinea during the last 40 000 yr

    Directory of Open Access Journals (Sweden)

    X. Crosta

    2011-07-01

    Full Text Available Opal content and diatom assemblages were analysed in core GeoB4905-4 to reconstruct siliceous productivity changes in the eastern Gulf of Guinea during the last 40 000 yr. Opal and total diatom accumulation rates presented low values over the considered period, except during the Last Glacial Maximum and between 12 000 calendar years (12 cal. ka BP and 5.5 cal. ka BP, the so-called African Humid Period, when accumulation rates of brackish and freshwater diatoms to the core site were highest. Conversely, accumulation rates of windblown diatoms exhibited an opposite pattern with higher values before and after the African Humid Period and greatest values during Heinrich Events, the Younger Dryas and since 5.5 cal. ka BP.

    Our results demonstrate that siliceous productivity in the eastern Gulf of Guinea was directly driven by the nutrient load from local rivers, which discharges were forced by precipitation over western Equatorial Africa. Precipitation in this region is controlled by the West African monsoon which is, in turn, dependent on the presence and intensity of the Atlantic Cold Tongue (ACT. The ACT was weakened and warmer, trade winds were less vigorous, could convection and precipitation were greater during the AHP though centennial-to-millennial timescale dry events were observed at ~10 cal. ka BP, ∼8.5 cal. ka BP and ∼6 cal. ka BP. Conversely, the ACT was more intense, trade winds were more vigorous and African climate was more arid during H1, the Younger Dryas and since 5.5 cal. ka BP. Our results therefore give indication on the ocean and atmosphere dynamics over the last 40 000 yr.

  4. 76 FR 82057 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Coastal Migratory Pelagic...

    Science.gov (United States)

    2011-12-29

    ... in the management unit for the FMP. The overfishing status of these stocks is unknown, except that... regulation as the status quo. As set forth fully in Amendment 18, landings data for all four species proposed... the Gulf and Atlantic migratory groups are either administrative or allow status quo harvest...

  5. Species Profiles. Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (Gulf of Mexico). SHEEPSHEAD.

    Science.gov (United States)

    GULF , MOLLUSCA , NORTH(DIRECTION), OFFSHORE, PROFILES, RANGE(EXTREMES), RATES, RECREATION, REQUIREMENTS, STRUCTURES, TAXONOMY, TEMPERATURE, TROPICAL REGIONS, WATER, YOUTH, LIFE CYCLES, REPRODUCTION(PHYSIOLOGY)...IMPACT STATEMENTS, ENVIRONMENTS, ESTUARIES, GRASSES, GROWTH(GENERAL), HABITATS, HISTORY, INSHORE AREAS, INVERTEBRATES, LANDING, LIFE(BIOLOGY), MEXICO

  6. Gelatinous zooplankton assemblages in temperate coastal waters - seasonal variations (Gulf of Trieste, Adriatic Sea):

    OpenAIRE

    Malej, Alenka; Miloš, Čarna

    2005-01-01

    Gelatinous plankton composition, abundance, biomass and their seasonality was studied in the Gulf of Trieste (Adriatic Sea) over a yearly cycle. The most diversive gelatinous groups were Hydromedusae with 14 species, followed by Siphonophora (six species), Appendicularia (five species), Chaetognatha (two species), and Thaliacea (one species)....

  7. The distribution and composition of REE-bearing minerals in placers of the Atlantic and Gulf coastal plains, USA

    Science.gov (United States)

    Bern, Carleton; Shah, Anjana K.; Benzel, William M.; Lowers, Heather

    2016-01-01

    Rare earth element (REE) resources are currently of great interest because of their importance as raw materials for high-technology manufacturing. The REE-phosphates monazite (light REE enriched) and xenotime (heavy REE enriched) resist weathering and can accumulate in placer deposits as part of the heavy mineral assemblage. The Atlantic and Gulf coastal plains of the southeastern United States are known to host heavy mineral deposits with economic concentrations of zircon, ilmenite and rutile. This study provides a perspective on the distribution and composition of REE phosphate minerals in the region. The elemental chemistry and mineralogy of sands and associated heavy-mineral assemblages from new and archived sediment samples across the coastal plains are examined, along with phase-specific compositions of monazite, xenotime and zircon. Both monazite and xenotime are present across the coastal plains. The phase-specific compositions allow monazite content to be estimated using La as a geochemical proxy. Similarly, both Y and Yb are geochemical proxies for xenotime, but their additional presence in zircon and monazite require a correction to prevent overestimation of xenotime content. Applying this correction, maps of monazite and xenotime content across the coastal plains were generated using sample coverage from the National Geochemical Database (NGS) and National Uranium Resource Evaluation (NURE). The NGS and NURE approach of sampling stream sediments in small watersheds links samples to nearby lithologies. The results show an approximately 40 km-wide band of primarily Cretaceous, marine sediments bordering the Piedmont province from North Carolina to Alabama in which monazite and xenotime content are relatively high (up to 4.4 wt. % in < 150 μm bulk sediment). Strong correlations between concentrations of the two phases were found, with estimated monazite:xenotime ratios ranging approximately 6:1 to 12:1 depending upon the dataset analyzed. From a resource

  8. Patterns of the loop current system and regions of sea surface height variability in the eastern Gulf of Mexico revealed by the self-organizing maps

    Science.gov (United States)

    Liu, Yonggang; Weisberg, Robert H.; Vignudelli, Stefano; Mitchum, Gary T.

    2016-04-01

    The Self-Organizing Map (SOM), an unsupervised learning neural network, is employed to extract patterns evinced by the Loop Current (LC) system and to identify regions of sea surface height (SSH) variability in the eastern Gulf of Mexico (GoM) from 23 years (1993-2015) of altimetry data. Spatial patterns are characterized as different LC extensions and different stages in the process of LC eddy shedding. The temporal evolutions and the frequency of occurrences of these patterns are obtained, and the typical trajectories of the LC system progression on the SOM grid are investigated. For an elongated, northwest-extended, or west-positioned LC, it is common for the LC anticyclonic eddy (LCE) to separate and propagate into the western GoM, while an initially separated LCE in close proximity to the west Florida continental slope often reattaches to the LC and develops into an elongated LC, or reduces intensity locally before moving westward as a smaller eddy. Regions of differing SSH variations are also identified using the joint SOM-wavelet analysis. Along the general axis of the LC, SSH exhibits strong variability on time scales of 3 months to 2 years, also with energetic intraseasonal variations, which is consistent with the joint Empirical Orthogonal Function (EOF)-wavelet analysis. In the more peripheral regions, the SSH has a dominant seasonal variation that also projects across the coastal ocean. The SOM, when applied to both space and time domains of the same data, provides a powerful tool for diagnosing ocean processes from such different perspectives.

  9. A modeling study of coastal inundation induced by storm surge, sea-level rise, and subsidence in the Gulf of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Zhaoqing; Wang, Taiping; Leung, Lai-Yung R.; Hibbard, Kathleen A.; Janetos, Anthony C.; Kraucunas, Ian P.; Rice, Jennie S.; Preston, Benjamin; Wilbanks, Thomas

    2013-12-10

    The northern coasts of the Gulf of Mexico are highly vulnerable to the direct threats of climate change, such as hurricane-induced storm surge, and such risks can be potentially exacerbated by land subsidence and global sea level rise. This paper presents an application of a coastal storm surge model to study the coastal inundation process induced by tide and storm surge, and its response to the effects of land subsidence and sea level rise in the northern Gulf coast. An unstructured-grid Finite Volume Coastal Ocean Model was used to simulate tides and hurricane-induced storm surges in the Gulf of Mexico. Simulated distributions of co-amplitude and co-phase of semi-diurnal and diurnal tides are in good agreement with previous modeling studies. The storm surges induced by four historical hurricanes (Rita, Katrina, Ivan and Dolly) were simulated and compared to observed water levels at National Oceanic and Atmospheric Administration tide stations. Effects of coastal subsidence and future global sea level rise on coastal inundation in the Louisiana coast were evaluated using a parameter “change of inundation depth” through sensitivity simulations that were based on a projected future subsidence scenario and 1-m global sea level rise by the end of the century. Model results suggested that hurricane-induced storm surge height and coastal inundation could be exacerbated by future global sea level rise and subsidence, and that responses of storm surge and coastal inundation to the effects of sea level rise and subsidence are highly nonlinear and vary on temporal and spatial scales.

  10. Sound velocity, temperature, and salinity profiles from CTD and velocimeter casts by NOAA Ship FAIRWEATHER in Gulf of Alaska and coastal waters of SE Alaska from 2007-04-13 to 2007-10-31 (NCEI Accession 0036862)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Physical oceanographic data were collected from NOAA Ship FAIRWEATHER in Gulf of Alaska and coastal waters of SE Alaska from 13 April 2007 to 31 October 2007. Data...

  11. Policy frameworks for adaptation to climate change in coastal zones. The case of the Gulf of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Levina, E. [Organisation for Economic Co-operation and Development OECD, Paris (France); Jacob, J.S. [Texas Sea Grant, Texas Cooperative Extension, Texas A and M University System, Houston, TX (United States); Ramos Bustillos, L.E. [Ramos-Hoek Consultancy, Ajijic, Chapala (Mexico); Ortiz, I. [SAFS University of Washington, Washington DC (United States)

    2007-05-15

    This paper is the third in a series of AIXG (Annex I Expert Group on the United Nations Framework Convention on Climate Change (UNFCCC)) papers that analyse the roles that national policy frameworks of various sectors play in adaptation to climate change. Adaptation to climate change is unlikely to be a standalone process. It occurs within the existing sectoral and cross-sectoral policy frameworks, including legal provisions, institutional structures, policies and management practices, and is supported by the available information tools. The previous two papers focused on the water sector. The aim of this paper is to identify and analyse policy frameworks that are important for facilitating adaptation to climate change impacts in coastal zones. The paper is based on the analysis of the Gulf of Mexico. Two countries, the US and Mexico, are examined, with a focus on two aspects of coastal zones: wetlands and built environment. Next to these two sectors attention is paid to four components that construct policy frameworks, namely legal framework, institutional landscape, policies and management tools, and information. Following a brief introduction of the Gulf of Mexico region, its physical and economic characteristics, the paper takes a look at current climatic conditions and trends in the Gulf region and expected climate change impacts and the key vulnerabilities of the region to these changes (Section 2). The rational for the scope and focus of the sectoral analysis presented in this paper can also be found in Section 2. Section 3 focuses on the analysis of policy frameworks that govern wetlands in the US and Mexico and their links with adaptation. Section 4 focuses on the analysis of policy frameworks that govern the development of human settlements, and adaptation to climate change. Sections 3 and 4 follow a structure similar to the one that was used for the two previous papers on policy frameworks for adaptation in the water sector. Both sections examine

  12. Benthic fluxes of mercury during redox changes in pristine coastal marine sediments from the Gulf of Trieste (northern Adriatic Sea)

    Energy Technology Data Exchange (ETDEWEB)

    Koron, Neza [National Institute of Biology, Piran (Slovenia). Marine Biological Section; Faganeli, Jadran [National Institute of Biology, Piran (Slovenia). Marine Biological Section; Jozef Stefan Institute, Ljubljana (Slovenia). Dept. of Environmental Sciences

    2012-12-15

    Purpose: The Gulf of Trieste (northern Adriatic Sea) is an example of a coastal environment contaminated with mercury (Hg). Contamination is a consequence of nearly 500 years of activity at the Idrija Mine (western Slovenia), which is the second largest Hg mine in the world. Oxygen depletion can be common in the Gulf of Trieste due to late summer stratification of the water column and accumulation of labile organic matter. Since changing redox conditions can have an impact on Hg transformations, we studied the effect of oxygen depletion, in parallel with sulphide, iron (Fe), manganese (Mn), fluorescent dissolved organic matter (FDOM) and nitrogen (N) and phosphorus (P) availability, on total Hg and methylmercury (MeHg) fluxes from sediments. Materials and methods: Pore water concentrations and benthic fluxes of total dissolved Hg and MeHg were studied in situ and in microcosm laboratory experiments using flux chambers encompassing three different stages: oxic, anoxic and reoxidation. Results and discussion: Our experiments showed that in the oxic stage there were small effluxes of MeHg to the water column, which increased in the anoxic stage and dropped rapidly in a subsequent reoxic stage, showing influx. Our results support the hypothesis that MeHg desorption from reduced metal hydroxides under anoxic conditions, and co-precipitation with Fe-oxides and MeHg demethylation in the reoxidation stage, may play a major role in determining MeHg benthic fluxes. For Hg and MeHg, it appears that there is little relationship between their pore water distribution and flux and that of FDOM, i.e. humics. Conclusions: The results indicate that there was no significant difference in Hg and MeHg pore water levels and their benthic fluxes between the contaminated northern and central parts of the Gulf of Trieste and the pristine southern part. This suggests that shallow and stratified coastal marine environments, in general, represent areas with a risk of high benthic release of

  13. Bioavailability of cadmium, copper, mercury, lead, and zinc in subtropical coastal lagoons from the southeast Gulf of California using mangrove oysters (Crassostrea corteziensis and Crassostrea palmula).

    Science.gov (United States)

    Páez-Osuna, Federico; Osuna-Martínez, Carmen C

    2015-02-01

    Cadmium (Cd), copper (Cu), mercury (Hg), lead (Pb), and zinc (Zn) were assessed in the edible tissues of Crassrotrea corteziensis oysters collected during the rainy and dry seasons in 27 sites from 8 coastal lagoons of the southeast Gulf of California. In addition, C. palmula oysters were sampled at 9 sites from the same mangrove roots where C. corteziensis oysters were collected. Metal analyses were performed by flame atomic absorption spectrophotometry (Cd, Cu, and Zn), graphite furnace (Pb), and cold vapor detection (Hg). The obtained mean levels were (µg g(-1) dry weight) as follows: Cd 6.05 ± 2.77, Cu 60.0 ± 33.4, Hg 0.38 ± 0.17, Pb 1.11 ± 0.63, and Zn 777 ± 528 µg g(-1). For all metals except Hg, the concentrations were greater during dry season than during rainy seasons. The high levels, particularly that for Cd, were related to upwelling along the eastern Gulf of California. High Hg levels in the rainy season were associated with the transport of materials from the watershed to the lagoon. Shrimp farming, agriculture, and other sources were considered as potential sources to explain the differences in metal bioavailability in the 8 lagoons. The mean concentrations of Cd (Santa María-La Reforma lagoon), Cu [San Ignacio-Navachiste-El Macapule (SINM), Urías (URI), and Altata-Ensenada del Pabellón lagoons], and zinc (Zn) (URI, Santa María-Ohuira-Topolobampo, El Colorado, and SINM lagoons) during the dry season were greater than the maximum permissible limits. C. palmula collected in 8 sites where they were present simultaneously with C. corteziensis had consistently greater metal levels than C. corteziensis, but correlation analyses showed a high and significant (P < 0.05) correlation between metal concentrations in both species. The correlation equations obtained are useful where the same species is not distributed and is necessary to compare results from distinct regions.

  14. Wind-driven coastal-trapped waves off southern Tamaulipas and northern Veracruz, western Gulf of Mexico, during winter 2012-2013

    Science.gov (United States)

    Rivas, David

    2017-02-01

    Four months of observations from a near-coastal mooring, deployed off southern Tamaulipas-northern Veracruz coast (western Gulf of Mexico) during winter 2012-2013, provide velocity and pressure series in a coastal region where apparently no in-situ measurements have been formally reported. The observations show numerous events of intense alongshore velocities with magnitudes typically exceeding 30 cm s-1, related to intensified winds associated with cold fronts invading the western Gulf during fall-winter, via coastal-trapped motions coming from northern locations. These motions can be explained by a time-dependent coastal-trapped wave (CTW) mode, using a phase speed (∼4 m s-1) which is consistent with analyses of correlation/lag of historical sea level data, CTW dynamic modes, and sensitivity to such a phase speed. The CTW time-dependent mode reproduces most of the variability of the sea level and hence the alongshore barotropic velocity observed at the mooring, and it can also be used to estimate the contribution of remote regions to the variance observed at the central portion of the western Gulf (the mooring's location). More than half of that variance is generated in the southernmost coast of Texas and northernmost coast of Tamaulipas, and ∼40% is generated in the central and southern portions of Tamaulipas coast. Thus, the method described in this paper is useful not only to explain the near-coastal flow variability but it also presents the potential predictability of intensified-flow events in the western Gulf of Mexico.

  15. The Evolution of the Coastal Economy: The Role of Working Waterfronts in the Alabama Gulf Coast

    Directory of Open Access Journals (Sweden)

    Yaoqi Zhang

    2015-04-01

    Full Text Available This article describes the evolution of the coastal economy in Alabama and examines the driving forces of the sustainable economy in a historical context. The input-output model was applied to assess the direct and secondary effects of output and employment in the coastal region. Results suggest that state industries are heavily dependent on waterfront-related activities in this area, which have fueled much of their rapid development in the past few decades. Tourism, ship building and repairing and transportation are the three dominating sources contributing to the coastal economy. There are a few general problems of working waterfronts in the coastal Alabama area, but there are also some unique problems (e.g., Hurricane Katrina, Deepwater Horizon oil spill. Policies for future sustainable development are proposed.

  16. Maps showing distribution of the Middle Cretaceous unconformity in the eastern Gulf of Mexico

    Science.gov (United States)

    Massingill, L.M.; Wells, R.H.

    1987-01-01

    Several theories on the origin of the Gulf of Mexico basin have been introduced by various researchers (Beloussov, 1970; Freeland and Dietz, 1971; Malfait and Dinkelman, 1972; Wood and Walper, 1974; Pilger, 1978; Buffler and others, 1980; Dickinson and Coney, 1980; Gose and others, 1980; Schmidt-Effing, 1980; Walper, 1980; Schlager and others, 1984). Although no final agreement has been reached, one prominent geologic feature is generally recognized. The early evolution of the basin ended with a major middle Cretaceous event resulting in a Gulf-wide unconformity referred to as the middle Cretaceous unconformity (MCU). This event represents a major shift from Early Cretaceous shallow-water bank sedimentation to Late Cretaceous deeper water carbonates (Worzel and others, 1973; Mitchum, 1978).

  17. Seasonal patterns of bacterial communities in the coastal brackish sediments of the Gulf of Finland, Baltic Sea

    Science.gov (United States)

    Vetterli, Adrien; Hyytiäinen, Kirsi; Ahjos, Minttu; Auvinen, Petri; Paulin, Lars; Hietanen, Susanna; Leskinen, Elina

    2015-11-01

    Coastal areas are critical in mitigating the impact of nutrient runoffs and downstream eutrophication of aquatic ecosystems. In the Gulf of Finland, the easternmost sub-basin of the Baltic Sea, seasonal and long-term oxygen depletion at the surface of the sediment feeds back the eutrophication loop by promoting the release of nutrients locked in the sediment matrix. In order to understand how the bacterial community responds to the seasonal variations, we sequenced ribosomal gene fragments from the top sediment layer at two coastal sites in southern Finland in spring, summer and late autumn during two consecutive years. Analysis of the samples collected at a shallow (11 m) and deep site (33 m) revealed that the overall community composition was rather constant over time with an extensive collection of shared operational taxonomic units (OTU) between sites. The dominant taxa were related to organoheterotrophs and sulfate reducers and the variation in community structure was linked to the availability of organic matter in the surface sediment. Proteobacteria formed the most abundant and diverse group. The taxa characteristic of spring samples belonged primarily to Actinobacteria, possibly of fresh water origin and linked to humic carbon. Summer communities were characterized by an increase in the number of reads associated with heterotrophic bacteria such as Bacteroidetes which feed on labile organic matter from spring bloom. Taxa typical of autumn samples were linked to Cyanobacteria and other bloom-forming bacteria from the overlying water and to bacteria feeding on organic matter drifting from the phytal zone.

  18. Potential geologic hazards on the eastern Gulf of Cadiz slope (SW Spain)

    Science.gov (United States)

    Baraza, J.; Ercilla, G.; Nelson, C.H.

    1999-01-01

    Geologic hazards resulting from sedimentary, oceanographic and tectonic processes affect more than one third of the offshore Gulf of Cadiz, and are identified by interpreting high-resolution seismic profiles and sonographs. Hazards of sedimentary origin include the occurrence of slope instability processes in the form of single or multiple slumps occupying up to 147 km2 mainly concentrated in the steeper, upper slope area. Besides the presence of steep slopes, the triggering of submarine landslides is probably due to seismic activity and favoured by the presence of biogenic gas within the sediment. Gassy sediments and associated seafloor pockmarks cover more than 240 km2 in the upper slope. Hazards from oceanographic processes result from the complex system of bottom currents created by the interaction of the strong Mediterranean Undercurrent and the rough seafloor physiography. The local intensification of bottom currents is responsible for erosive processes along more than 1900 km2 in the upper slope and in the canyons eroded in the central area of the slope, undermining slopes and causing instability. The strong bottom currents also create a mobile seafloor containing bedforms in an area of the Gulf that extends more than 2500 km2, mostly in the continental slope terraces. Hazards of tectonic origin are important because the Gulf of Cadiz straddles two major tectonic regions, the Azores-Gibraltar fracture zone and the Betic range, which results in diapir uplift over an area of more than 1000 km2, and in active seismicity with earthquakes of moderate magnitude. Also, tsunamis produced by strong earthquakes occur in the Gulf of Cadiz, and are related to the tectonic activity along the Azores-Gibraltar fracture zone.

  19. Seagrass distribution and abundance in Eastern Gulf of Mexico coastal waters

    Science.gov (United States)

    Iverson, Richard L.; Bittaker, Henry F.

    1986-05-01

    The marine angiosperms Thalassia testudinum, Syringodium filiforme, and Halodule wrightii form two of the largest reported seagrass beds along the northwest and southern coasts of Florida where they cover about 3000 square km in the Big Bend area and about 5500 square km in Florida Bay, respectively. Most of the leaf biomass in the Big Bend area and outer Florida Bay was composed of Thalassia testudinum and Syringodium filiforme which were distributed throughout the beds but which were more abundant in shallow depths. A short-leaved form of Halodule wrightii grew in monotypic stands in shallow water near the inner edges of the beds, while Halophila decipiens and a longer-leaved variety of H. wrightii grew scattered throughout the beds, in monotypic stands near the outer edges of the beds, and in deeper water outside the beds. Halophila engelmanni was observed scattered at various depths throughout the seagrass beds and in monospecific patches in deep water outside the northern bed. Ruppia maritima grew primarily in brackish water around river mouths. The cross-shelf limits of the two major seagrass beds are controlled nearshore by increased water turbidity and lower salinity around river mouths and off-shore by light penetration to depths which receive 10% or more of sea surface photosynthetically active radiation. Seagrasses form large beds only along low energy reaches of the coast. The Florida Bay seagrass bed contained about twice the short-shoot density of both Thalassia testudinum and Syringodium filiforme, for data averaged over all depths, and about four times the average short-shoot density of both species in shallow water compared with the Big Bend seagrass bed. The differences in average seagrass abundance between Florida Bay and the Big Bend area may be a consequence of the effects of greater seasonal solar radiation and water temperature fluctuations experienced by plants in the northern bed, which lies at the northern distribution limit for American Tropical seagrasses.

  20. Physical, chemical, and deepwater current profiles collected from CTD, XBT, and ADCP moorings in the Eastern Gulf of Mexico from January 19, 2005 to January 28, 2006 (NODC Accession 0070922)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A Minerals Management Service (MMS) program entitled Survey of Deepwater Currents in the Eastern Gulf of Mexico, awarded to Evans-Hamilton, Inc. This data set...

  1. g175eg.m77t - MGD77 data file for Geophysical data from field activity G-1-75-EG in Eastern Gulf of Alaska, Continental Shelf from 06/22/1975 to 08/27/1975

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Single-beam bathymetry, gravity, and magnetic data along with DGPS navigation data was collected as part of field activity G-1-75-EG in Eastern Gulf of Alaska,...

  2. Assessment of heavy metals concentrations in coastal sediments in ...

    African Journals Online (AJOL)

    EJIRO

    are dangerous for sea wild life and for human food resources. ... Key words: Marine pollution, heavy metals, coastal sediments, toxicity, Nosy Be, .... source of Cd and Pb in sediments come from ferry port ..... Water Environment in the Eastern African Region. ... marine organisms from the Northern part of the Gulf of Suez, Red.

  3. Geomorphological map of a coastal stretch of north-eastern Gozo (Maltese archipelago, Mediterranean Sea)

    Science.gov (United States)

    Soldati, Mauro; Micallef, Anton; Biolchi, Sara; Chelli, Alessandro; Cuoghi, Alessandro; Devoto, Stefano; Gauci, Christopher; Graff, Kevin; Lolli, Federico; Mantovani, Matteo; Mastronuzzi, Giuseppe; Pisani, Luca; Prampolini, Mariacristina; Restall, Brian; Roulland, Thomas; Saliba, Michael; Selmi, Lidia; Vandelli, Vittoria

    2017-04-01

    Geomorphological investigations carried out along the north-eastern coast of the Island of Gozo (Malta) have led to the production of a detailed geomorphological map. Field surveys, accompanied by aerial photo-interpretation, were carried out within the framework of the EUR-OPA Major Hazards Agreement Project ``Developing Geomorphological mapping skills and datasets in anticipation of subsequent Susceptibility, Vulnerability, Hazard and Risk Mapping'' (Council of Europe). In particular, this geomorphological map is the main output of a `Training Course on Geomorphological Mapping in Coastal Areas' held within the Project in November 2016. The study area selected was between Ramla Bay and Dacrhlet Qorrot Bay on the Island of Gozo (67 km2), part of the Maltese archipelago in the central Mediterranean Sea. From a geological viewpoint, the stratigraphic sequence includes Late Oligocene (Chattian) to Late Miocene (Messinian) sedimentary rocks. The hard limestones of the Upper Coralline Limestone Formation, the youngest lithostratigraphic unit, dominate the study area. Underlying this formation, marls and clays belonging to the Blue Clay Formation extensively outcrop. The oldest lithostratigraphic unit observed in the study area is the Globigerina Limestone Formation, a fine-grained limestone. The lithostructural features of the outcropping units clearly condition the morphography of the landscape. The coast is characterised by the alternation of inlets and promontories. Worthy of notice is the large sandy beach of Ramla Bay partly backed by dunes. From a geomorphological perspective, the investigated coastal stretch is characterised by limestone plateaus bounded by steep structural scarps which are reshaped by gravitational and/or degradation processes, and milder slopes in Blue Clays at their foot comprising of numerous rock block deposits (rdum in Maltese) and active or abandoned terraced fields used for agricultural purposes. Landforms and processes related to

  4. Styela plicata: a new promising bioindicator of heavy metal pollution for eastern Aegean Sea coastal waters.

    Science.gov (United States)

    Aydın-Önen, S

    2016-11-01

    As part of a research project, the concentrations of Cd, Cu, Pb, V, and Zn in the tissues of Styela plicata were investigated for the first time to determine if S. plicata is a suitable biological indicator for biomonitoring of heavy metals in eastern Aegean Sea coastal waters. To examine the relationships, heavy metal levels in suspended particulate matters (SPMs) and sediments were also determined. According to the results, the mean metal levels in SPM, sediments, and S. plicata samples could be arranged in the following order of abundance: Zn > Cu > Pb > V > Cd. As for heavy metal levels, significant positive correlations were noted between Cd-Pb, Cd-V, Cd-Zn, Cu-V, and Pb-V in SPM; Cd-Zn, Cu-Zn, Pb-Cd, Pb-Cu, and Pb-Zn in sediment; and Cu-Pb, Cu-Zn, and Pb-Zn in S. plicata samples. Positive relationships between these metals showed that they were originated from same sources and that they were associated with each other. Based on the findings, Zn, Cu, and Pb concentrations in suspended particulate matters, sediments, and S. plicata samples were generally represented with higher levels at stations that were used for boating, shipping, and related activities. As S. plicata is a strongest accumulator of V, the relatively low V levels observed in this study may indicate the lack of anthropogenic sources of this metal in the sampling stations. In conclusion, suspended particulate matter and sediment can be useful tool to detect the pollution status of the marine environment. Furthermore, the findings of this study highlighted that S. plicata is a promising alternative for the monitoring of heavy metal pollution for eastern Aegean Sea coasts.

  5. Heavy metal contamination and ecological risk assessment in the surface sediments of the coastal area surrounding the industrial complex of Gabes city, Gulf of Gabes, SE Tunisia.

    Science.gov (United States)

    El Zrelli, Radhouan; Courjault-Radé, Pierre; Rabaoui, Lotfi; Castet, Sylvie; Michel, Sylvain; Bejaoui, Nejla

    2015-12-30

    In the present study, the concentrations of 6 trace metals (Hg, Cd, Cu, Pb, Cr and Zn) were assessed in the surface sediments of the central coastal area of Gabes Gulf to determine their contamination status, source, spatial distribution and ecological risks. The ranking of metal contents was found to be Zn>Cd>Cr>Pb>Cu>Hg. Correlation analysis indicated that Cd and Zn derived mainly from the Tunisian Chemical Group phosphogypsum. The other pollutants may originate from other industrial wastes. Metallic contamination was detected in the south of chemical complex, especially in the inter-harbor zone, where the ecological risk of surface sediments is the highest, implying potential negative impacts of industrial pollutants. The spatial distribution of pollutants seems to be due to the effect of harbor installations and coastal currents. The metallic pollution status of surface sediments of Gabes Gulf is obvious, very worrying and requires rapid intervention.

  6. Coastal sea level variability in the eastern English Channel: Potentialities for future SWOT applicability

    Science.gov (United States)

    Turki, Imen; Laignel, Benoit; Chevalier, Laetitia; Costa, Stephane

    2014-05-01

    Scientists and engineers need to understand the sea level variability in order to provide better estimates of the sea level rise for coastal defense using tide gauges and radar altimetry missions. The natural limitation of the tide gauge records is their geographical sparsity and confinement to coastlines. The future Surface Water and Ocean Topography (SWOT) mission will be launched in 2015 over a period of 5 years and will be designated to address this issue. This research was carried out in the framework of the program Surface Water and Ocean Topography (SWOT) which is a partnership between NASA and CNES. Using a series of statistical analyses, we point to characterize the sea level variability in the eastern English Channel (western France) from four tide gauges in Dunkirk, Dieppe, Le Havre and Cherbourg for the period 1964-2012. To assess the extent to which tide gauge point observations represent tide gauge data, we compare tide gauge records to SWOT measurements in their vicinity. Results have shown that the bimodality of the sea level, provided by the distribution analysis, can be reproduced by SWOT measurements with an overestimation of both modes and also the extreme values. The rate of the linear regression was also overestimated from 1.7-4 mm/yr to 2.6-5.4 mm/yr. The continuous wavelet transform of sea level records has shown the large-scale variability of annual (1-year band) and interannual cycles (2-6- and 6-12-year bands) in sea level, which can be explained by oceanographic and hydrological factors. High frequency dynamics of the sea level variability at short time-scales were extracted from SWOT measurements. They provide a good survey of the surge events (band of 3-4 months) and the spring-neap tidal cycle (band of 28 days). Then, tide gauges should be used in conjunction with satellite data to infer the full time-scale variability. Further studies are needed to refine the SWOT applicability in coastal areas. Key words: coastal zone, sea level

  7. EAARL Coastal Topography-Eastern Florida, Post-Hurricane Jeanne, 2004: First Surface

    Science.gov (United States)

    Fredericks, Xan; Nayegandhi, Amar; Bonisteel-Cormier, J.M.; Wright, C.W.; Sallenger, A.H.; Brock, J.C.; Klipp, E.S.; Nagle, D.B.

    2010-01-01

    These remotely sensed, geographically referenced elevation measurements of lidar-derived first-surface (FS) topography datasets were produced collaboratively by the U.S. Geological Survey (USGS), St. Petersburg Coastal and Marine Science Center, St. Petersburg, FL, and the National Aeronautics and Space Administration (NASA), Wallops Flight Facility, VA. This project provides highly detailed and accurate datasets of a portion of the eastern Florida coastline beachface, acquired post-Hurricane Jeanne (September 2004 hurricane) on October 1, 2004. The datasets are made available for use as a management tool to research scientists and natural-resource managers. An innovative airborne lidar instrument originally developed at the NASA Wallops Flight Facility, and known as the Experimental Advanced Airborne Research Lidar (EAARL), was used during data acquisition. The EAARL system is a raster-scanning, waveform-resolving, green-wavelength (532-nanometer) lidar designed to map near-shore bathymetry, topography, and vegetation structure simultaneously. The EAARL sensor suite includes the raster-scanning, water-penetrating full-waveform adaptive lidar, a down-looking red-green-blue (RGB) digital camera, a high-resolution multispectral color-infrared (CIR) camera, two precision dual-frequency kinematic carrier-phase GPS receivers, and an integrated miniature digital inertial measurement unit, which provide for sub-meter georeferencing of each laser sample. The nominal EAARL platform is a twin-engine Cessna 310 aircraft, but the instrument may be deployed on a range of light aircraft. A single pilot, a lidar operator, and a data analyst constitute the crew for most survey operations. This sensor has the potential to make significant contributions in measuring sub-aerial and submarine coastal topography within cross-environmental surveys. Elevation measurements were collected over the survey area using the EAARL system, and the resulting data were then processed using the

  8. EAARL Coastal Topography-Eastern Louisiana Barrier Islands, Post-Hurricane Gustav, 2008: First Surface

    Science.gov (United States)

    Bonisteel-Cormier, J.M.; Nayegandhi, Amar; Wright, C.W.; Sallenger, A.H.; Brock, J.C.; Nagle, D.B.; Vivekanandan, Saisudha; Fredericks, Xan

    2010-01-01

    These remotely sensed, geographically referenced elevation measurements of lidar-derived first-surface (FS) topography datasets were produced collaboratively by the U.S. Geological Survey (USGS), St. Petersburg Coastal and Marine Science Center, St. Petersburg, FL, and the National Aeronautics and Space Administration (NASA), Wallops Flight Facility, VA. This project provides highly detailed and accurate datasets of a portion of the eastern Louisiana barrier islands, acquired post-Hurricane Gustav (September 2008 hurricane) on September 6 and 7, 2008. The datasets are made available for use as a management tool to research scientists and natural-resource managers. An innovative airborne lidar instrument originally developed at the NASA Wallops Flight Facility, and known as the Experimental Advanced Airborne Research Lidar (EAARL), was used during data acquisition. The EAARL system is a raster-scanning, waveform-resolving, green-wavelength (532-nanometer) lidar designed to map near-shore bathymetry, topography, and vegetation structure simultaneously. The EAARL sensor suite includes the raster-scanning, water-penetrating full-waveform adaptive lidar, a down-looking red-green-blue (RGB) digital camera, a high-resolution multispectral color infrared (CIR) camera, two precision dual-frequency kinematic carrier-phase GPS receivers, and an integrated miniature digital inertial measurement unit, which provide for sub-meter georeferencing of each laser sample. The nominal EAARL platform is a twin-engine Cessna 310 aircraft, but the instrument may be deployed on a range of light aircraft. A single pilot, a lidar operator, and a data analyst constitute the crew for most survey operations. This sensor has the potential to make significant contributions in measuring sub-aerial and submarine coastal topography within cross-environmental surveys. Elevation measurements were collected over the survey area using the EAARL system, and the resulting data were then processed using

  9. Geologic assessment of undiscovered oil and gas resources: Oligocene Frio and Anahuac Formations, United States Gulf of Mexico coastal plain and State waters

    Science.gov (United States)

    Swanson, Sharon M.; Karlsen, Alexander W.; Valentine, Brett J.

    2013-01-01

    The Oligocene Frio and Anahuac Formations were assessed as part of the 2007 U.S. Geological Survey (USGS) assessment of Tertiary strata of the U.S. Gulf of Mexico Basin onshore and State waters. The Frio Formation, which consists of sand-rich fluvio-deltaic systems, has been one of the largest hydrocarbon producers from the Paleogene in the Gulf of Mexico. The Anahuac Formation, an extensive transgressive marine shale overlying the Frio Formation, contains deltaic and slope sandstones in Louisiana and Texas and carbonate rocks in the eastern Gulf of Mexico. In downdip areas of the Frio and Anahuac Formations, traps associated with faulted, rollover anticlines are common. Structural traps commonly occur in combination with stratigraphic traps. Faulted salt domes in the Frio and Anahuac Formations are present in the Houston embayment of Texas and in south Louisiana. In the Frio Formation, stratigraphic traps are found in fluvial, deltaic, barrier-bar, shelf, and strandplain systems. The USGS Tertiary Assessment Team defined a single, Upper Jurassic-Cretaceous-Tertiary Composite Total Petroleum System (TPS) for the Gulf Coast basin, based on previous studies and geochemical analysis of oils in the Gulf Coast basin. The primary source rocks for oil and gas within Cenozoic petroleum systems, including Frio Formation reservoirs, in the northern, onshore Gulf Coastal region consist of coal and shale rich in organic matter within the Wilcox Group (Paleocene–Eocene), with some contributions from the Sparta Sand of the Claiborne Group (Eocene). The Jurassic Smackover Formation and Cretaceous Eagle Ford Formation also may have contributed substantial petroleum to Cenozoic reservoirs. Modeling studies of thermal maturity by the USGS Tertiary Assessment Team indicate that downdip portions of the basal Wilcox Group reached sufficient thermal maturity to generate hydrocarbons by early Eocene; this early maturation is the result of rapid sediment accumulation in the early

  10. The results of monitoring of hazardous natural processes in the coastal shelf zone of the gulf of Peter the Great in 2012-2013

    Science.gov (United States)

    Anokhin, Vladimir; Shcherbakov, Victor; Motychko, Victor; Sokolov, Georgy; Kotov, Sergey; Kartashov, Alexander; Anokhina (1)(2), Zoya

    2014-05-01

    The monitoring of hazardous natural processes In coastal and shelf zone of the gulf of Peter the Great (sea of Japan) in 2012-2013 was made by staff of the Gramberg Institute VNIIOKEANGEOLOGIA . The complex of field researches are: - laser scanning beaches (tachometer Leica HDS 3000); - echosounding underwater coastal slope (sounder-Navigator LCX-37C); - high-frequency acoustic profiling (GeoPulse Subbotom Profilier); - hydromagnetic shooting magnetometer SeaSPY Marine Magnetics; - sonar shooting (complex GEO-CM-MAX); - research of the water column (sounding and sampling); - bottom sampling, including gasgeochemical shooting. The result of this work is the following conclusions: 1. As the shore, and the underwater slope of the district are experiencing the preemptive destruction, the areas of which are quantitative and spatially prevail over the stable and accumulate zones (except the shores of the inland parts of bays and gulfs). 2. The rate of destruction of coast in the Gulf of Peter the Great is 1-20 meters for 100 years, that could pose a serious danger to the population and infrastructure. 3. Number of gasgeochemical anomalies on the shelf of the Gulf of Peter the Great spatially associated with fault lines, limiting blocks of the earth's crust within shelf. 4. Perhaps it is these faults are of the greatest seismic hazard in the moment. 5. Danger of themselves gas emissions The following significant hazards and risks to the region have been studied: seismic and tsunami destruction of shore, gas emissions, technogenic pollution.

  11. Coastal aquaculture development in eastern Africa and the Western Indian Ocean: prospects and problems for food security and local economies.

    Science.gov (United States)

    Rönnback, Patrik; Bryceson, Ian; Kautsky, Nils

    2002-12-01

    This paper reviews the experience and status of coastal aquaculture of seaweeds, mollusks, fish and crustaceans in eastern Africa and the islands of the western Indian Ocean. In many respects, coastal aquaculture is still in its infancy in the region, and there is a pressing need to formulate development strategies aimed at improving the income and assuring the availability of affordable protein to coastal communities. This paper also draws from positive and negative experiences in other parts of the world. The requirements of feed and fry, and the conversion of mangroves are used to illustrate how some aquaculture activities constitute a net loss to global seafood production. The paper presents both general and specific sustainability guidelines based on the acknowledgement of aquaculture as an ecological process. It is concluded that without clear recognition of its dependence on natural ecosystems, the aquaculture industry is unlikely to develop to its full potential in the region.

  12. Agroforestry and its Application in Amelioration of Saline Soils in Eastern China Coastal Region

    Institute of Scientific and Technical Information of China (English)

    Zhang Jianfeng; Xing Shangjun; Li Jiyue; F.Makeschin; Song Yumin

    2004-01-01

    Some environmental problems, especially soil salinity hinder the regional sustainable development of eastern China coastal region. Salinity mainly comes from tide weave, seawater flooding and seawater intrusion. Over exploitation of groundwater, which is the result of unfitful land use systems, leads to seawater intrusion and salt concentration increase. Agroforestry systems can enrich soil fertility and prevent soil salinization, furthermore help maintain biodiversity and enhance productivity. For the intergrated multiple ecosystems the most critical issue is to select optimum tree species and rationally arrange these plants. The basics of this multiple ecosystem is that different plants will occupy variable ecological niches within an area, both in space and in soil depth. Shelterbelts and trees intercropping with agricultural crops are major types of the multiple ecosystem. Shelterbelts can reduce wind speed and consequently lessen evaporation and erosion of the soil, increase pasture growth by up to 60% on exposed sites, increase crop yields by up to 25%. Besides intercropping with jujube, other agroforestry multiple ecosystem such as forestry plus agriculture, forestry plus agriculture plus fishery, and forestry plus animal husbandry are the most appropriate ways to utilise land resource in this region.

  13. Implications of modelled radioactivity measurements along coastal Odisha, Eastern India for heavy mineral resources

    Science.gov (United States)

    Ghosal, S.; Agrahari, S.; Guin, R.; Sengupta, D.

    2017-01-01

    A radioelemental assemblage assessment of two beaches of Odisha is performed for the first time. The radiation is measured in two ways, both on field with the help of a hand held environmental survey meter and in the laboratory, where the concentrations of radionuclide's 238U, 232Th and 4K have been determined with the help of High Purity Germanium detector (HPGe). Mineralogical analysis of selected samples has been performed with the help of X-Ray Fluorescence Spectrometry (XRF). A marked difference between the concentration of Uranium (274 Bq kg-1) and Thorium (2489 Bq kg-1) is observed and discussed based on the geology of the area. The placer deposits showing an enrichment of thorium can be an important source of nuclear fuel for the thorium based nuclear reactors. The ratio of thorium and uranium concentrations gives us an idea about the coastal processes associated with the beach. Statistical analysis of the data shows a positive correlation between 238U and 232Th and a strong negative correlation is indicated between 4 K and 238U, 232Th. A cross plot between the equivalent thorium and the equivalent uranium and the equivalent thorium and potassium, represents the nature of deposition and its association with the heavy mineral along with the radioactive elements. Heavy minerals exhibit an increasing trend towards Northeast-Southwest along the south eastern coast of India.

  14. Benthic community indicators over a long period of monitoring (2000-2012) of the Saronikos Gulf, Greece, Eastern Mediterranean.

    Science.gov (United States)

    Simboura, N; Zenetos, A; Pancucci-Papadopoulou, M A

    2014-06-01

    An analysis of the results of the 12-year regular monitoring (2000-2012) of benthic communities in Saronikos Gulf and Elefsis Bay (Eastern Mediterranean, Greece) in relation to the functioning of the Psittalia Wastewater Treatment Plant (WWTP) and advances in treatment is presented. Benthic community indicators applied include the Bentix index adopted for the implementation of the Water Framework Directive (WFD); the diversity and species richness proposed in combination with the Bentix index for the evaluation of certain attributes of the Sea-floor Integrity descriptor for the marine waters of Greece, under the Marine Strategy Framework Directive (MSFD), and the evenness index. The benthic and environmental data were treated according to the distance from the outfall, largely accounting for the variance of the indicators, to investigate trends along the monitoring. Results showed an upgrade of the condition of the benthic communities of Saronikos Gulf throughout the monitoring period mostly demonstrated by the Bentix and diversity indices. A change in the trends of most indices was especially evident after 2004, especially in the areas more adjacent to the outfall zones, when the advanced secondary biological treatment plant was completed and commissioned. Sediment parameters' trend patterns indicate a delayed reaction to recovery processes in relation to benthic indices. An evaluation of the current status of the benthic communities based on the indices applied showed a gradient from a moderate ecological status at stations up to a distance of 8,000 m from the outfalls to good environmental and ecological status at more remote stations. At shallower stations located at a distance of more than 4,000 m from the outfall, benthic communities also present good environmental status. In Elefsis Bay, the enclosed physiography, shallower depth and local pressures result in more adverse environmental conditions for benthic communities and a more complex influence from WWTP

  15. Historical reconstruction of mangrove expansion in the Gulf of Mexico: Linking climate change with carbon sequestration in coastal wetlands

    Science.gov (United States)

    Bianchi, Thomas S.; Allison, Mead A.; Zhao, Jun; Li, Xinxin; Comeaux, Rebecca S.; Feagin, Rusty A.; Kulawardhana, R. Wasantha

    2013-03-01

    There has been considerable interest in a recently recognized and important sink in the global carbon pool, commonly referred to as "blue carbon". The major goal of this study was to determine the historical reconstruction of mangrove expansion (Avicennia germinans) into salt marshes (Spartina alterniflora) and its effects on carbon sequestration and soil chemistry in wetland soils of the northwestern Gulf of Mexico. We used bulk stable isotopic, chemical biomarker analyses, and aerial imagery analysis to identify changes in OC wetland sources, and radiotracers (137Cs and 210Pb) for chronology. Soil cores were collected at two sites at Port Aransas, Texas (USA), Harbor Island and Mud Island. Stable isotopic values of δ13C and δ15N of all soil samples ranged from -26.8 to -15.6‰ and 1.8-10.4‰ and showed a significant trend of increasing depletion for each isotope from bottom to surface soils. The most depleted δ13C values were in surface soils at the Mud Island (Mangrove 2) location. Carbon sequestration rates were greater in mangroves and for the Mud Island Mangrove 1 and the Marsh 1 sites ranged from 253 to 270 and 101-125 g C m-2 yr-1, respectively. Lignin storage rates were also greater for mangrove sites and for the Mud Island Mangrove 1 and the Marsh 1 ranged from 19.5 to 20.1 and 16.5 to 12.8 g lignin m-2 yr-1, respectively. Τhe Λ8 and Λ6 values for all cores ranged from 0.5 to 21.5 and 0.4 to 16.5, respectively, and showed a significant increase from bottom to surface sediments. If regional changes in the Gulf of Mexico are to persist and much of the marsh vegetation was to be replaced by mangroves, there could be significant increases on the overall storage and sequestration of carbon in the coastal zone.

  16. Polycyclic aromatic hydrocarbons in surface seawater and in indigenous mussels ( Mytilus galloprovincialis) from coastal areas of the Saronikos Gulf (Greece)

    Science.gov (United States)

    Valavanidis, A.; Vlachogianni, Th.; Triantafillaki, S.; Dassenakis, M.; Androutsos, F.; Scoullos, M.

    2008-09-01

    Polycyclic aromatic hydrocarbons (PAHs) were identified and measured in surface seawater and in the tissues (gills and mantle) of indigenous black mussels, Mytilus galloprovincialis, collected from three coastal sites of Saronikos Gulf (Greece), a gulf that exhibits high levels of pollution. The total PAHs measured by spectrofluorometry in the surface seawater were found in the range of 425-459 ng L -1 at the most polluted sites 1 and 2 (Elefsis Bay-Salamis Island) and in the range of 103-124 ng L -1 at site 3 (Aegina Island). PAHs' sources in seawater were identified by application of specific PAH ratios, such as phenanthrene/anthracene and fluoranthene/pyrene. Levels of PAHs in soft tissues (gills and mantle) of indigenous mussels were much higher than those reported for seawater. Total PAH concentrations in mantle tissues were in the range of 1300-1800 ng g -1 dry weight (dw) tissue at sites 1 and 2 and approximately 380 ng g -1 dw at site 3. In gill tissues total PAH concentrations were in the range of 1480-2400 ng g -1 dw at sites 1 and 2 and approximately 430 ng g -1 dw at site 3. PAHs composition was dominated by two-, three- and four-ring compounds in seawater, where 17 different PAH compounds were identified and measured in mussel tissues. Mussels can be used as sentinel organisms to monitoring PAHs' contamination, since they concentrate PAHs from the surrounding water media and therefore making the chemical analysis simpler and less prone to error than that for water. In surface seawater possible weathering and photodegradation due to hot climates contribute to reduced PAHs concentrations.

  17. Concentrations and sources of polycyclic aromatic hydrocarbons in surface coastal sediments of the northern Gulf of Mexico

    Science.gov (United States)

    2014-01-01

    Background Coastal sediments in the northern Gulf of Mexico have a high potential of being contaminated by petroleum hydrocarbons, such as polycyclic aromatic hydrocarbons (PAHs), due to extensive petroleum exploration and transportation activities. In this study we evaluated the spatial distribution and contamination sources of PAHs, as well as the bioavailable fraction in the bulk PAH pool, in surface marsh and shelf sediments (top 5 cm) of the northern Gulf of Mexico. Results PAH concentrations in this region ranged from 100 to 856 ng g−1, with the highest concentrations in Mississippi River mouth sediments followed by marsh sediments and then the lowest concentrations in shelf sediments. The PAH concentrations correlated positively with atomic C/N ratios of sedimentary organic matter (OM), suggesting that terrestrial OM preferentially sorbs PAHs relative to marine OM. PAHs with 2 rings were more abundant than those with 5–6 rings in continental shelf sediments, while the opposite was found in marsh sediments. This distribution pattern suggests different contamination sources between shelf and marsh sediments. Based on diagnostic ratios of PAH isomers and principal component analysis, shelf sediment PAHs were petrogenic and those from marsh sediments were pyrogenic. The proportions of bioavailable PAHs in total PAHs were low, ranging from 0.02% to 0.06%, with higher fractions found in marsh than shelf sediments. Conclusion PAH distribution and composition differences between marsh and shelf sediments were influenced by grain size, contamination sources, and the types of organic matter associated with PAHs. Concentrations of PAHs in the study area were below effects low-range, suggesting a low risk to organisms and limited transfer of PAHs into food web. From the source analysis, PAHs in shelf sediments mainly originated from direct petroleum contamination, while those in marsh sediments were from combustion of fossil fuels. PMID:24641695

  18. Sediment Quality in Near Coastal Waters of the Gulf of Mexico: Influence of Hurricane Katrina

    Science.gov (United States)

    The results from this study represent a synoptic analysis of sediment quality in coastal waters of Lake Pontchartrain and Mississippi Sound two months after the landfall of Hurricane Katrina. Post-hurricane conditions were compared to pre-hurricane (2000-2004) conditions, for se...

  19. Mean trophic level of coastal fisheries landings in the Persian Gulf (Hormuzgan Province), 2002-2011

    Science.gov (United States)

    Razzaghi, Marzieh; Mashjoor, Sakineh; Kamrani, Ehsan

    2016-06-01

    Fishing activities can alter the structure of marine food webs by the selective removal of some species. The changes in the marine food webs of the Hormuzgan waters of the Persian Gulf, Iran were assessed, based on estimates of the mean trophic index (MTI) and Fishing in Balance index (FiB), and on landing profile of the exploited marine community (49 species) during the period, 2002-2011. The total landings (Y t) (R=0.88, Pprocess is occurring in this area, and that this trend may continue in the long-term. Therefore, environmental fisheries management and conservation programs should be prioritized for these valuable resources.

  20. Acoustic profiling and surface imaging of the coastal area near the subduction zone: the eastern coastal area of Boso Peninsula, Central Japan.

    Science.gov (United States)

    Furuyama, S.; Sato, T.

    2016-12-01

    The plate motion of the Philippine Sea plate and the Pacific plate influences geology of coastal area in the Pacific side in Japan and sometime causes extensive damage of human activity, such as the Great East Japan Earthquake. It is important to understand the geological structures in a coastal area for disaster prevention. Especially, rapid equipment of geoinformations is highly demanded in the Kanto region where covers capital Tokyo area. Geological Survey of Japan investigated the eastern coastal area in Boso Peninsula, eastern part of the Kanto region, Japan within two years from 2014 to 2015. We obtained seismic sections of ca. 1100 km in total length with a boomer and multi-channel streamer (24 channel with 3.125 m spacing) and report the geological significance of the subsurface structures. The survey area is divided into the northern part of Kujukuri area, the southern part of Kujukuri area, the coastal part of Kujukuri area based on topography and geological structures. In these Kujukuri areas, two strata that show distinct stratification bounded by distinct unconformity distribute and we define them as the Kujukuri A Unit and the Kujukuri B Unit, in ascending order. The lower sequence has some folds and normal faults. These folds that deformed the Kujukuri B Unit extend toward north-northeast in the northern part of Kujukuri area. They contributed to development of wide shelf distributed in this area. In the southern part of Kujukuri area, a lot of faults deformed the Kujukuri B Unit and some of them displaced the Kujukuri A Unit over 10 msec (two way travel). Normal faults developed in the Kujukuri B Unit over 10 msec made grabens and half grabens in the coastal part of Kujukuri area and these grabens and half grabens could make the lowland in the Kujukuri coastal area. The combination of these geological structures identified in the Kujukuri areas could reflect the transition of stress field associated with the subduction of the Philippine Sea plate

  1. Habitat type and nursery function for coastal marine fish species, with emphasis on the Eastern Cape region, South Africa

    Science.gov (United States)

    Whitfield, Alan K.; Pattrick, Paula

    2015-07-01

    A considerable amount of research has been undertaken to document and assess the nursery function of a variety of coastal habitats for marine fish species around the world. Most of these studies have focused on particular habitats and have generally been confined to a limited range of fish species associated with specific nursery areas. In this review we conduct a general assessment of the state of knowledge of coastal habitats in fulfilling the nursery-role concept for marine fishes, with particular emphasis on biotic and abiotic factors that influence nursery value. A primary aim was to synthesize information that can be used to drive sound conservation planning and provide a conceptual framework so that new marine protected areas (MPAs) incorporate the full range of nursery areas that are present within the coastal zone. We also use published data from a coastal section in the Eastern Cape Province, South Africa, to highlight the differential use of shallow aquatic habitats by a range of juvenile marine fish species within this region. Although the Eastern Cape case study does not assess the relative growth, food availability or predation in nursery and non-nursery areas within the coastal zone, it does document which habitats are important to the juveniles of dominant marine species within each area. These habitats, which range from intertidal pools, subtidal gulleys and surf zones to estuaries, do appear to perform a key role in the biological success of species assemblages, with the juveniles of particular marine fishes tending to favour specific nursery areas. According to a multivariate analysis of nursery habitat use within this region, marine species using estuaries tend to differ considerably from those using nearshore coastal waters, with a similar pattern likely to occur elsewhere in the world.

  2. Variations in organic carbon chemistry in the Gulf Coast and coastal marshes following the Deepwater Horizon oil spill

    Science.gov (United States)

    Holloway, J. M.; Orem, W. H.; Aiken, G.; Varonka, M. S.; Butler, K.; Kokaly, R. F.

    2011-12-01

    Record volumes of oil released from the Macondo well following the explosion of the Deepwater Horizon offshore oil-drilling platform in the Gulf of Mexico significantly impacted coastal marshes in Barataria Bay, Louisiana. Remote sensing and water sampling was conducted by the U.S. Geological Survey to evaluate the extent of impact. Water samples were collected offshore from near the spill site July 5-10, 2010 to characterize molecular organic carbon chemistry on unfiltered samples and dissolved organic carbon (DOC) on filtered samples. Three field visits were conducted in July 7-10, August 12-14, and August 24-26, 2010, to collect samples from the soil-water interface in coastal marshes along lower Barataria Bay and the Bird's Foot Delta at the distal end of the Mississippi River Delta. Visible oil in the marsh was observed as thick coatings on vegetation and soil and as sheens at the water surface. Samples were extracted for hydrocarbons with dichloromethane, separated into aliphatic, aromatic and polar compound classes using standard column techniques, and analyzed by gas chromatography/mass spectrometry. A significant amount of oil was observed "dissolved" in the water column with a hydrocarbon distribution resembling that of the surface oil slick. While oils maintained many of the more volatile lower molecular weight components near the spill site, these were mostly gone in the onshore Barataria Bay samples, leaving mostly higher molecular weight components. Dissolved organic carbon was characterized using concentration, fluorescence index (FI), specific ultratviolet absorbance (SUVA) and excitation/emission fluorescence (EEM). Offshore samples had distinctive EEMs patterns, SUVA and FI. With few exceptions, marsh samples had EEMs patterns more similar to previously extracted organic matter from the Mississippi River than to the offshore oil. In spite of visible oil sheen in unfiltered water from contaminated shorelines and no visible sign of impact on

  3. OCEAN COLOR RETRIEVAL USING LANDSAT-8 IMAGERY IN COASTAL CASE 2 WATERS (CASE STUDY PERSIAN AND OMAN GULF

    Directory of Open Access Journals (Sweden)

    N. Moradi

    2016-06-01

    (λ2/(λ1, the three bands ratio with variable [(λ1−1−(λ2−1]×(λ3 and four bands ratio with variable [(λ1−1−(λ2−1]/[(λ4−1−(λ3−1] that desired wavelength (i.e. λ1, λ2, λ3 and λ4 in the range of red and near-infrared wavelengths of the electromagnetic spectrum are in the region of the Persian Gulf and Oman Sea look. Despite the high importance of the Persian Gulf and Oman Sea which can have up basin countries, to now few studies have been done in this area. The focus of this article on the northern part of Oman Sea and Persian Gulf, the shores of neighboring Iran (case 2 water. In this paper, by using Landsat 8 satellite imageries, we have discussed chla concentrations and customizing different OC algorithms for this new dataset (Landsat-8 imagery. This satellite was launched in 2013 and its data using two sensors continuously are provided operating one sensor imager land (OLI: Operational Land Imager and the Thermal Infrared Sensor (TIRS: Thermal InfraRed Sensor and are available. This sensors collect image data, respectively, for the nine-band short wavelength in the range of 433-2300 nm and dual-band long wavelength thermal. Seven band of the nine band picked up by the sensor information of OLI to deal with sensors TM (Thematic Mapper and ETM+ (Enhanced Thematic Mapper Plus in previous satellite Landsat compatible and two other band, the band of coastal water (433 to 453 nm and Cirrus band (1360 to 1390 nm, short wave infrared provides to measure water quality and high thin clouds. Since OLI sensor in Landsat satellite 8 compared with other sensors to study OC have been allocated a much better spatial resolution can be more accurate to determine changes in OC. To evaluate the results of the image sensor MODIS (Moderate Resolution Imaging Spectroradiometer at the same time satellite images Landsat 8 is used. The statistical parameters used in order to evaluate the performance of different algorithms, including root mean square error

  4. Phytoplankton variation and its relation to nutrients and allochthonous organic matter in a coastal lagoon on the Gulf of Mexico

    Science.gov (United States)

    Aké-Castillo, José A.; Vázquez, Gabriela

    2008-07-01

    In tropical and subtropical zones, coastal lagoons are surrounded by mangrove communities which are a source of high quantity organic matter that enters the aquatic system through litter fall. This organic matter decomposes, becoming a source of nutrients and other substances such as tannins, fulvic acids and humic acids that may affect the composition and productivity of phytoplankton communities. Sontecomapan is a coastal lagoon located in the southern Gulf of Mexico, which receives abundant litter fall from mangrove. To study the phytoplankton composition and its variation in this lagoon from October 2002 to October 2003, we evaluated the concentrations of dissolved folin phenol active substances (FPAS) as a measure of plant organic matter, salinity, temperature, pH, O 2, N-NH 4+, N-NO 3-, P-PO 43-, Si-SiO 2, and phytoplanktonic cell density in different mangrove influence zones including the three main rivers that feed the lagoon. Nutrients concentrations depended on freshwater from rivers, however these varied seasonally. Concentrations of P-PO 43-, N-NH 4+ and FPAS were the highest in the dry season, when maximum mangrove litter fall is reported. Variation of these nutrients seemed to depend on the internal biogeochemical processes of the lagoon. Blooms of diatoms ( Skeletonema spp., Cyclotella spp. and Chaetoceros holsaticus) and dinoflagellates ( Peridinium aff. quinquecorne, Prorocentrum cordatum) occurred seasonally and in the different mangrove influence zones. The high cell densities in these zones and the occurrence of certain species and its ordination along gradient of FPAS in a canonical correspondence analysis, suggest that plant organic matter (i.e. mangrove influence) may contribute to phytoplankton dynamics in Sontecomapan lagoon.

  5. Functional response of midsummer planktonic and benthic communities in the Neva Estuary (eastern Gulf of Finland to anthropogenic stress

    Directory of Open Access Journals (Sweden)

    Sergey M. Golubkov

    2003-03-01

    Full Text Available Long-term hydrobiological research has shown that the functioning of the ecosystem of the Neva Estuary, one of the largest Baltic estuaries, has changed greatly since the beginning of the 20th century. Ineffective local water management in St. Petersburg during thelast twenty years has stimulated the development of a natural "biological plug" in the salt barrier zone in the inner part ofthe estuary and has altered the ecosystem's functioning. These changes include an increase in primary production, in the primary production:organic matter decomposition ratio, and in pelagic-benthic coupling. It has also given rise to filamentous algae blooms and intensive secondary pollution in the coastal zone of the Neva Estuary. The primary production of phytoplankton in the inner part of the estuary has reached 2.3 gC m-2, that of the filamentous algae Cladophora glomerata 5.5 gC m-2 these figures are much higher than in other regions of the Gulf of Finland.

  6. The effect of large anthropogenic particulate emissions on atmospheric aerosols, deposition and bioindicators in the eastern Gulf of Finland region.

    Science.gov (United States)

    Jalkanen, L; Mäkinen, A; Häsänen, E; Juhanoja, J

    2000-10-30

    The effect of the emissions from large oil shale fuelled power plants and a cement factory in Estonia on the elemental concentration of atmospheric aerosols, deposition, elemental composition of mosses and ecological effects on mosses, lichens and pine trees in the eastern Gulf of Finland region has been studied. In addition to chemical analysis, fly ash, moss and aerosol samples were analysed by a scanning electron microscope with an energy dispersive X-ray spectrometer (SEM/EDS). The massive particulate calcium emissions, approximately 60 kton/year (1992), is clearly observed in the aerosols, deposition and mosses. The calcium deposition is largest next to the Russian border downwind from the power plants and in south-eastern part of Finland. This deposition has decreased due to the application of dust removal systems at the particulate emission sources. At the Virolahti EMEP station approximately 140 km north from the emission sources, elevated elemental atmospheric aerosol concentrations are observed for Al, Ca, Fe, K and Si and during episodes many trace elements, such as As, Br, Mo, Ni, Pb and V. The acidification of the soil is negligible because of the high content of basic cations in the deposition. Visible symptoms on pine trees are negligible. However, in moss samples close to the power plants, up to 25% of the leaf surface was covered by particles. Many epiphytic lichen species do not tolerate basic stemflow and on the other hand most species are also very sensitive for the SO2 content in air. Consequently a large lichen desert is found in an area of 2500 km2 in the vicinity of the power plants with only one out of the investigated 12 species growing.

  7. Long-term observations of Alaska Coastal Current in the northern Gulf of Alaska

    Science.gov (United States)

    Stabeno, Phyllis J.; Bell, Shaun; Cheng, Wei; Danielson, Seth; Kachel, Nancy B.; Mordy, Calvin W.

    2016-10-01

    The Alaska Coastal Current is a continuous, well-defined system extending for ~1700 km along the coast of Alaska from Seward, Alaska to Samalga Pass in the Aleutian Islands. The currents in this region are examined using data collected at >20 mooring sites and from >400 satellite-tracked drifters. While not continuous, the mooring data span a 30 year period (1984-2014). Using current meter data collected at a dozen mooring sites spread over four lines (Seward, Gore Point, Kennedy and Stevenson Entrances, and the exit to Shelikof Strait) total transport was calculated. Transport was significantly correlated with alongshore winds, although the correlation at the Seward Line was weak. The largest mean transport in the Alaska Coastal Current occurred at Gore Point (1.4×106 m3 s-1 in winter and 0.6×106 m3 s-1 in summer), with the transport at the exit to Shelikof Strait (1.3×106 m3 s-1 in winter and 0.6×106 m3 s-1 in summer) only slightly less. The transport was modified at the Seward Line in late summer and fall by frontal undulations associated with strong river discharge that enters onto the shelf at that time of year. The interaction of the Alaska Coastal Current and tidal currents with shallow banks in the vicinity of Kodiak Archipeligo and in Kennedy-Stevenson Entrance results in mixing and prolonged primary production throughout the summer.

  8. Abstracts and final report of the Southern Gulf of St. Lawrence Coalition on Sustainability workshop on climate change and coastal communities: concerns and challenges for today and beyond

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-11-01

    The participants at this workshop presented important climate change information from a national perspective and provided an opportunity for stakeholder comments on the Southeastern New Brunswick Sea-Level Rise Project. The abstracts presented in this report outlined current research on ocean current variabilities; climate change and coastal erosion impacts in the Gulf of St. Lawrence estuary; and agriculture and climate change. Community focus presentations addressed issues associated with coastal vulnerability to climate change and sea-level rise in Haida Gwaii, BC; Inuit observations of climate change; impacts and adaptation to climate change in Atlantic Canada; and communities, fisheries and tourism. Future research orientations from governments were also examined, with information on protection policies for coastal areas; climate change impact and adaptation directorates; climate change scenarios; and potential impacts and possible adaptations to the communities in the region. The studies indicate that the sea level will rise by 70 cm by the year 2100 in the southeastern Gulf of St. Lawrence. Immediate implementation of New Brunswick's Coastal Areas Protection Policy was recommended. Climate change is an issue that contains ecological, social and economic aspects, linking science to local knowledge. This final report contains 25 abstracts presented at the conference. A participant list and an appendix of the workshop's agenda was also included.

  9. Marine geo-hazard in the Campi Flegrei coastal area (Eastern Tyrrhenian sea)

    Science.gov (United States)

    Violante, C.; Angelino, A.; Buonocunto, F. P.; di Fiore, V.; Esposito, E.; Molisso, F.; Porfido, S.; Sacchi, M.

    2009-04-01

    The Campi Flegrei (i.e. "burning plains") are located on the eastern Tyrrhenian margin, an area characterized by active tectonics and volcanism since the Pleistocene. It is a densely urbanized coastal zone, including the bay of Pozzuoli, Procida and Ischia islands, where documented human activities have been developing for more than two thousand years. In the Pozzuoli area two major periods of eruptive volcanic activity occurred from 10.0 to 8.0 ky B.P and 4.5 to 3.7 ky B.P. These periods were followed by the September 1538 Monte Nuovo eruption. Numerous monogenic volcanoes formed close to the shoreline and volcanic debris interpreted as submarine counterpart of subaerial flow and surge, has been detected offshore. The most recent volcanic activity on Ischia island starts around 10.0 ky B.P. to which associates several eruptive centres mostly located in the western sector. The last eruption dates back to Arso flow in 1302. Nevertheless the landscape of Ischia is dominated by Mount Epomeo in the central part of the island, which is the highest peak (788 m). It is a volcano-tectonic structure that raised above sea level between 33 and 28 ka BP, due to the intrusion of magma at shallow depth. In the Campi Flegrei, magma-related activity is testified by extensive hydrothermalism, and recent episodes (1883 on Ischia, and 1970-71 and 1982-84 on Pozzuoli coast) of shallow seismicity and ground deformation, exceeding rates of 100 cm/year in the years 1983-1984. Volcanic and volcano-tectonic activity mainly associate with inferred resurgent calderas whose uplift have caused mass wasting phenomena, faulting and erosional activity both on land and at sea. Major geohazard features resulting from marine geophysical and sedimentological investigations include (1) extensive landslide deposits and associated hummocky topographies off Ischia volcanic island, (2) seafloor instabilities in the form of creep/slump, channelled sediment flow and deep sedimentary fan, (3) superficial

  10. Native and alien ichthyofauna in coastal fishery of Rhodes (eastern Mediterranean (2002-2010

    Directory of Open Access Journals (Sweden)

    Maria Corsini-Foka

    2015-11-01

    Full Text Available Rhodes Island (southeastern Aegean is located in a geographically crucial region subjected to biological invasions. Among the 108 alien species recorded, 30 are fish, all of Indo-Pacific/Red Sea origin introduced via Suez through Lessepsian migration (Corsini-Foka et al., 2015; Corsini-Foka and Kondylatos, In press; Kondylatos and Corsini-Foka, In press. In this oligotrophic area, fishery production is limited, due to the paucity of species of commercial interest and their low abundance, while adapted infrastructures for fish landing and marketing are absent. Coastal fishery has dominated during the last twenty years (ELSTAT, 2015. Within 2002-2010, the Hydrobiological Station of Rhodes conducted experimental boat seining surveys, using exclusively a professional 12m fishing boat, at 5-30 m depth, in the Gulf of Trianda (sandy mud, Posidonia meadows. The 94 carried out hauls (7-18 hauls/year, produced a total fish biomass of approximately 4400 Kg, recording 97 fish (86 native, 11 alien and 4 cephalopod species (3 native, 1 alien. Fish species ranged from 32 to 63/year, whereas aliens ranged from 5 to 8 species. Almost steadily present since 2002, were earlier colonizers such as Apogonichthyoides pharaonis, Siganus rivulatus, Siganus luridus, Stephanolepis diaspros and more recent ones as Pteragogus trispilus, Sphyraena chrysotaenia and Fistularia commersonii, while Lagocephalus sceleratus, firstly recorded in 2005, occurred regularly since 2007; the presence of Lagocephalus suezensis, Sphyraena flavicauda and Upeneus pori was scattered since their first records in 2004-2005. Alien fish commercially important are the Siganids, S. chrysotaenia and surprisingly F. commersonii. In terms of biomass per haul, alien fish ranged from 0 to 18.5 Kg, native from 1.5 to 182 Kg. Catches were dominated by Centracanthidae (Spicara spp. and Sparidae (Boops boops, sometimes by other native such as Oblada melanura, Diplodus spp., Chromis Chromis and others. The

  11. Heavy metal concentrations in marine green, brown, and red seaweeds from coastal waters of Yemen, the Gulf of Aden

    Science.gov (United States)

    Al-Shwafi, Nabil A.; Rushdi, Ahmed I.

    2008-08-01

    The purpose of this study was to investigate the concentration levels of heavy metals in different species of the main three marine algal divisions from the Gulf of Aden coastal waters, Yemen. The divisions included Chlorophyta—green plants ( Halimeda tuna, Rhizoclonium kochiamum, Caldophora koiei, Enteromorpha compressa, and Caulerpa racemosa species), Phaeophyta—brown seaweeds ( Padina boryana, Turbinaria elatensis, Sargassum binderi, Cystoseira myrica, and Sargassum boveanum species), and Rhodophyta—red seaweeds ( Hypnea cornuta, Champia parvula, Galaxaura marginate, Laurencia paniculata, Gracilaria foliifere, and species). The heavy metals, which included cadmium (Cd), cobalt (Co), copper (Cu), chromium (Cr), Iron (Fe), manganese (Mn), nickel (Ni), lead (Pb), zinc (Zn), and vanadium (V) were measured by Atomic Absorption Spectrophotometer (AAs). The concentrations of heavy metals in all algal species are in the order of Fe >> Cu > Mn > Cr > Zn > Ni > Pb > Cd > V > Co. The results also showed that the uptake of heavy metals by different marine algal divisions was in the order of Chlorophyta > Phaeophyta > Rhodophyta. These heavy metals were several order of magnitude higher than the concentrations of the same metals in seawater. This indicates that marine alga progressively uptake heavy metals from seawater.

  12. Evaluation of sediment contamination by monoaromatic hydrocarbons in the coastal lagoons of Gulf of Saros, NE Aegean Sea.

    Science.gov (United States)

    Ünlü, Selma; Alpar, Bedri

    2017-05-15

    The concentrations and distribution of monoaromatic hydrocarbons (benzene, toluene, ethyl benzene and the sum of m-, p- and o-, xylenes) were determined in the sediments of coastal lagoons of the Gulf of Saros, using a static headspace GC-MS. The total concentrations of BTEX compounds ranged from 368.5 to below detection limit 0.6μgkg(-1) dw, with a mean value of 61.5μgkg(-1) dw. The light aromatic fraction of m-, p-xylene was the most abundant compound (57.1% in average), and followed by toluene (38.1%)>ethylbenzene (4.1%)>o-xylene (2.5%)>benzene (1.1%). The factor analysis indicated that the levels and distribution of BTEX compounds depend on the type of contaminant source (mobile/point), absorbance of compounds in sediment, and mobility of benzene compound and degradation processes. Point sources are mainly related to agricultural facilities and port activities while the dispersion of compounds are related with their solubility, volatility and effect of sea/saline waters on lagoons. Copyright © 2017. Published by Elsevier Ltd.

  13. Geochemistry and petrogenesis of Quaternary volcanism from the islets in the eastern Beibu Gulf:evidence for Hainan plume

    Institute of Scientific and Technical Information of China (English)

    LI Naisheng; YAN Quanshu; CHEN Zhihua; SHI Xuefa

    2013-01-01

    Some of the islets in the eastern Beibu Gulf are covered by Quaternary volcano strata. The rock samples from these islets mainly consist of quartz tholeiites (at Shenjiandao), olivine tholeiites (at Linshidao and Xieyang-dao) and alkali basalts (at Yangpubi and Jianshidao), and basically represent four periods of the Quaternary volcanism of Hainan Island and its adjacent regions. Except for the samples from Shenjiandao, most of the Quaternary volcanics of these islets belong to alkali magma series. The trace element characteristics of all of these samples show they are OIB (oceanic island basalt)-like, which implies that their deep geodynamic setting may be related to a mantle plume. The Sr-Nd-Pb isotopic compositions show that the mantle source beneath the Quaternary strata can be regarded as a result of binary mixing between a depleted, DMM (de-pleted MORB mantle)-like source and an enriched mantle type 2 (EM2). The EM2 may be originated from the Hainan mantle plume, and has been metasomatized by carbonaceous fluids released from ancient re-cycled oceanic crust at an asthenospheric mantle level. These features, together with typical trace element ratios, reflect that the parent magma was not subjected to crustal contamination during its ascent to the surface. This study provides further petrological and geochemical evidence for the existence of the Hainan mantle plume.

  14. Quantification of Boat Visitation Rates at Artificial and Natural Reefs in the Eastern Gulf of Mexico Using Acoustic Recorders.

    Science.gov (United States)

    Simard, Peter; Wall, Kara R; Mann, David A; Wall, Carrie C; Stallings, Christopher D

    2016-01-01

    Artificial reefs are commonly used as a management tool, in part to provide ecosystem services, including opportunities for recreational fishing and diving. Quantifying the use of artificial reefs by recreational boaters is essential for determining their value as ecosystem services. In this study, four artificial-natural reef pairs in the eastern Gulf of Mexico (off western Florida) were investigated for boat visitation rates using autonomous acoustic recorders. Digital SpectroGram (DSG) recorders were used to collect sound files from April 2013 to March 2015. An automatic detection algorithm was used to identify boat noise in individual files using the harmonic peaks generated by boat engines, and by comparing the sound amplitude of each file with surrounding files. In all four pairs, visitation rates were significantly higher at the artificial reef than the natural reef. This increase in boat visitation was likely due to actual or perceived increased quality of fishing and diving at the artificial reefs, or to lack of knowledge of the presence or locations of the natural reefs. Inshore reefs (25 m depth). This study appears to be the first to use acoustic data to measure participant use of boating destinations, and highlights the utility of acoustic monitoring for the valuation of this important ecosystem service provided by artificial reefs.

  15. Quantification of Boat Visitation Rates at Artificial and Natural Reefs in the Eastern Gulf of Mexico Using Acoustic Recorders

    Science.gov (United States)

    Simard, Peter; Wall, Kara R.; Mann, David A.; Wall, Carrie C.; Stallings, Christopher D.

    2016-01-01

    Artificial reefs are commonly used as a management tool, in part to provide ecosystem services, including opportunities for recreational fishing and diving. Quantifying the use of artificial reefs by recreational boaters is essential for determining their value as ecosystem services. In this study, four artificial–natural reef pairs in the eastern Gulf of Mexico (off western Florida) were investigated for boat visitation rates using autonomous acoustic recorders. Digital SpectroGram (DSG) recorders were used to collect sound files from April 2013 to March 2015. An automatic detection algorithm was used to identify boat noise in individual files using the harmonic peaks generated by boat engines, and by comparing the sound amplitude of each file with surrounding files. In all four pairs, visitation rates were significantly higher at the artificial reef than the natural reef. This increase in boat visitation was likely due to actual or perceived increased quality of fishing and diving at the artificial reefs, or to lack of knowledge of the presence or locations of the natural reefs. Inshore reefs (25 m depth). This study appears to be the first to use acoustic data to measure participant use of boating destinations, and highlights the utility of acoustic monitoring for the valuation of this important ecosystem service provided by artificial reefs. PMID:27500533

  16. Ocean Color Retrieval Using LANDSAT-8 Imagery in Coastal Case 2 Waters (case Study Persian and Oman Gulf)

    Science.gov (United States)

    Moradi, N.; Hasanlou, M.; Saadatseresht, M.

    2016-06-01

    Ocean color (OC) monitoring using satellite imageries provides an appropriate tool for a better understanding of marine processes and changes in the coastal environment. Radiance measurements in the range of visible light of the electromagnetic spectrum provides information of ocean color that is associated with the water constituents. This measurements are used to monitor the level of biological activity and the presence of particles in the water. Ocean features such as the concentration of chlorophyll, suspended sediment concentration and sea surface temperature have a significant impact on the dynamics of the ocean. The concentration of chlorophyll (chla), active pigments of phytoplankton photosynthesis, as a key indicator applied for assessment of water quality and biochemistry. Experimental algorithms chla related to internal communication various optical components in the water that may be change in space and time in the water with different optical characteristics. Therefore, the algorithms have been developed for one area may not work for other places and each region according to its specific characteristics needs that determined by an algorithm may be appropriate to local. We have tried treatment several algorithms for determination of chlorophyll, including experimental algorithms with a simple band ratio of blue-green band (i.e. OCx) and algorithms includes two bands ratio with variable 𝑅𝑟𝑠(λ2)/𝑅𝑟𝑠(λ1), the three bands ratio with variable [𝑅𝑟𝑠(λ1)-1-𝑅𝑟𝑠(λ2)-1]×𝑅𝑟𝑠(λ3) and four bands ratio with variable [𝑅𝑟𝑠(λ1)-1-𝑅𝑟𝑠(λ2)-1]/[𝑅𝑟𝑠(λ4)-1-𝑅𝑟𝑠(λ3)-1] that desired wavelength (i.e. λ1, λ2, λ3 and λ4) in the range of red and near-infrared wavelengths of the electromagnetic spectrum are in the region of the Persian Gulf and Oman Sea look

  17. Variation of Surface Ozone Recorded at the Eastern Coastal Region of the Malaysian Peninsula

    Directory of Open Access Journals (Sweden)

    Aida S. Ismail

    2010-01-01

    Full Text Available Problem statement: Variations of ozone (O3 concentrations in the Eastern Coastal Region of the Malaysia peninsula were investigated using data obtained from the Malaysian Department of the Environment. The aim of this study was to determine the monthly and seasonal variations of ozone concentrations at all monitoring sites. This study deals with the air quality data recorded at four air quality monitoring stations in the East Coast of the Malaysian peninsula over a ten year period (1997- 2006. Approach: We focused on the usage of S-Plus and SPSS to analyze this data. The S-Plus programming was used to impute missing data and SPSS was used to obtain the variations of ozone and also to clarify the relationship between stations. Results: Over the entire 10 year period (1997- 2006, the trend in annual baseline ozone generally increased each year for all the four monitoring sites. There was also a seasonal variability in the measured ozone levels with high concentrations during the southwest monsoon and the northeast monsoon season, producing a significant increase in the amplitude of the seasonal cycle. The results also shown that the highest ozone concentrations were recorded at the Bukit Kuang air monitoring station (S1, with a daily mean value of 19 ppb followed by the Indera Mahkota air monitoring station (S2. The concentration of ozone recorded at Kota Bharu (S3 and Kuala Terengganu (S4, two stations located in the city centre, was found to be lower than the values recorded at Bukit Kuang and Indera Mahkota. The correlation between O3 and NO is high at Kuala Terengganu (S4 (ñ = -0.579, whilst the relationship between O3 and NO2 are high (ñ = -0.397 at Indera Mahkota (S2. Conclusion: The concentration of ozone in the East Coast of Malaysian peninsula depends on the concentration of NOx and seasonal meteorological factors.

  18. Toxic heavy metals in sediments, seawater, and molluscs in the eastern and western coastal waters of Guangdong Province, South China.

    Science.gov (United States)

    Zhang, Ling; Shi, Zhen; Zhang, Jingping; Jiang, Zhijian; Wang, Fei; Huang, Xiaoping

    2016-05-01

    Heavy metal concentrations and distribution were studied in sediments, seawater, and molluscs, and the possible heavy metal sources in the coastal waters of Guangdong Province, South China were discussed. The results showed that the concentrations of Cu, Pb, Zn, and Cr in sediments in eastern coastal waters were generally higher than those in the western coastal waters. However, concentrations of most metals in seawater and molluscs in western waters were higher than in the eastern waters, which was tightly related to the local economics and urbanization development, especially, the different industrial structure in two regions. The main heavy metal sources were attributed to the industrial and agricultural effluent, domestic sewage, and even waste gas. Furthermore, heavy metal contamination assessment indicated that high contamination levels of Cd, Zn, and Pb occurred in sediments in local areas, especially in the bays and harbors. The metal accumulation levels by molluscs ranked following the order of Cd > Cu > As > Zn > Pb > Cr, and the ecological risks introduced by heavy metals in different areas were in the order of Zhanjiang > Yangmao > Shantou > Shanhui.

  19. Improved Oil Recovery from Upper Jurassic Smackover Carbonates through the Application of Advanced Technologies at Womack Hill Oil Field, Choctaw and Clarke Counties, Eastern Gulf Costal Plain

    Energy Technology Data Exchange (ETDEWEB)

    Ernest A. Mancini

    2006-05-31

    Pruet Production Co. and the Center for Sedimentary Basin Studies at the University of Alabama, in cooperation with Texas A&M University, Mississippi State University, University of Mississippi, and Wayne Stafford and Associates proposed a three-phase, focused, comprehensive, integrated and multidisciplinary study of Upper Jurassic Smackover carbonates (Class II Reservoir), involving reservoir characterization and 3-D modeling (Phase I) and a field demonstration project (Phases II and III) at Womack Hill Field Unit, Choctaw and Clarke Counties, Alabama, eastern Gulf Coastal Plain. Phase I of the project has been completed. The principal objectives of the project are: increasing the productivity and profitability of the Womack Hill Field Unit, thereby extending the economic life of this Class II Reservoir and transferring effectively and in a timely manner the knowledge gained and technology developed from this project to producers who are operating other domestic fields with Class II Reservoirs. The major tasks of the project included reservoir characterization, recovery technology analysis, recovery technology evaluation, and the decision to implement a demonstration project. Reservoir characterization consisted of geoscientific reservoir characterization, petrophysical and engineering property characterization, microbial characterization, and integration of the characterization data. Recovery technology analysis included 3-D geologic modeling, reservoir simulation, and microbial core experiments. Recovery technology evaluation consisted of acquiring and evaluating new high quality 2-D seismic data, evaluating the existing pressure maintenance project in the Womack Hill Field Unit, and evaluating the concept of an immobilized enzyme technology project for the Womack Hill Field Unit. The decision to implement a demonstration project essentially resulted in the decision on whether to conduct an infill drilling project in Womack Hill Field. Reservoir performance

  20. Assessment of the geothermal/geopressure potential of the Gulf Coastal Plan of Alabama. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, G.V.; Wang, G.C.; Mancini, E.A.; Benson, D.J.

    1980-01-01

    Geothermal and geopressure as well as geologic and geophysical data were studied to evaluate the potential for future development of geothermal resources underlying the Alabama Coastal Plain. Wire-line log data compiled and interpreted from more than 1300 oil and gas test wells included maximum recorded temperatures, mud weights, rock resistivities as related to geopressure, formation tops, fault locations, and depths to basement rock. The Alabama Coastal Plain area is underlain by a conduction dominated, deep sedimentary basin where geothermal gradients are low to moderate (1.0 to 1.8/sup 0/F/100 feet). In some areas of southwest Alabama, abnormally high temperatures are found in association with geopressured zones within the Haynesville Formation of Jurassic age; however, rocks of poor reservoir quality dominate this formation, with the exception of a 200-square-mile area centered in southernmost Clarke County where a porous and permeable sand unit is encased within massive salt deposits of the lower Haynesville. The results of a petrograhic study of the Smackover Formation, which underlies the Haynesville, indicate that this carbonate rock unit has sufficient porosity in some areas to be considered a potential geothermal reservoir. Future development of geothermal resources in south Alabama will be restricted to low or moderate temperature, non-electric applications, which constitute a significant potential energy source for applications in space heating and cooling and certain agricultural and industrial processes.

  1. Assessment of the geothermal/geopressure potential of the Gulf Coastal Plan of Alabama. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, G.V.; Wang, G.C.; Mancini, E.A.; Benson, D.J.

    1980-01-01

    Geothermal and geopressure as well as geologic and geophysical data were studied to evaluate the potential for future development of geothermal resources underlying the Alabama Coastal Plain. Wire-line log data compiled and interpreted from more than 1300 oil and gas test wells included maximum recorded temperatures, mud weights, rock resistivities as related to geopressure, formation tops, fault locations, and depths to basement rock. The Alabama Coastal Plain area is underlain by a conduction dominated, deep sedimentary basin where geothermal gradients are low to moderate (1.0 to 1.8/sup 0/F/100 feet). In some areas of southwest Alabama, abnormally high temperatures are found in association with geopressured zones within the Haynesville Formation of Jurassic age; however, rocks of poor reservoir quality dominate this formation, with the exception of a 200-square-mile area centered in southernmost Clarke County where a porous and permeable sand unit is encased within massive salt deposits of the lower Haynesville. The results of a petrograhic study of the Smackover Formation, which underlies the Haynesville, indicate that this carbonate rock unit has sufficient porosity in some areas to be considered a potential geothermal reservoir. Future development of geothermal resources in south Alabama will be restricted to low or moderate temperature, non-electric applications, which constitute a significant potential energy source for applications in space heating and cooling and certain agricultural and industrial processes.

  2. Toxic Nodularia spumigena blooms in the coastal waters of the Gulf of Gdańsk: a ten-year survey

    Directory of Open Access Journals (Sweden)

    Hanna Mazur-Marzec

    2006-06-01

    Full Text Available In the Baltic Sea, summer blooms of the filamentous, nitrogen-fixingcyanobacterium Nodularia spumigena are favoured by high P concentrationsat low N:P ratios and a salinity range of 5-13 PSU. The bloomsare initiated by calm and sunny weather, an elevated surfacewater temperature and thermal stratification. The mass occurrenceof N. spumigena in coastal waters is a matter of special concern,as the cyanobacterium produces nodularin, a potent pentapeptidehepatotoxin. In the Gulf of Gdansk, the large-scale occurrenceof N. spumigena was recorded for the first time in 1994. Bloomsof a similar intensity occurred in 2001, 2003 and 2004. Nodularinconcentrations in freeze-dried bloom samples varied from 0.01to 4.01 mg g-1 d.w. In the coastal waters of the Gulf of Gdańsk,cell-bound nodularin concentrations in 2004 and 2005 attainedmaxima of 25852 ± 107 µg dm-3 and3964 ± 125 µg dm-3, respectively. Microscopic analysis revealedthe presence of diverse N. spumigena forms, with the dominance of curvedfilaments in bloom samples. The results of in situ studies and remotesensing measurements indicate a high frequency and intensity of cyanobacterialblooms in the Gulf of Gdańsk in the last ten years.

  3. Mean trophic level of coastal fisheries landings in the Persian Gulf (Hormuzgan Province), 2002-2011

    Science.gov (United States)

    Razzaghi, Marzieh; Mashjoor, Sakineh; Kamrani, Ehsan

    2017-05-01

    Fishing activities can alter the structure of marine food webs by the selective removal of some species. The changes in the marine food webs of the Hormuzgan waters of the Persian Gulf, Iran were assessed, based on estimates of the mean trophic index (MTI) and Fishing in Balance index (FiB), and on landing profile of the exploited marine community (49 species) during the period, 2002-2011. The total landings ( Y t) ( R=0.88, Ptrend, which indicates exploitation of marine resources. The FiB index also showed a downward trend and negative values from 2002 to 2009, which may be associated with unbalanced structure in the fisheries, but an upward trend from 2009 to 2011. The time variation of the landing profile showed two periods with significant diff erences in their species composition ( R=0.88; P =0.005), and based on analysis of similarity, species have been identified as discriminator species, namely Thunnus albacores and Benthosema pterotum. Results indicate that changes in MTI reflected changes in the Hormuzgan landing structure. The examination of the MTI, FBI, and landing profile (LP) temporal pattern suggests that the status of fishery resources in Hormuzgan inshore waters is overexploited, and provides evidence of the probability that a fishing down process is occurring in this area, and that this trend may continue in the long-term. Therefore, environmental fisheries management and conservation programs should be prioritized for these valuable resources.

  4. Response of coastal fishes to the Gulf of Mexico oil disaster.

    Directory of Open Access Journals (Sweden)

    F Joel Fodrie

    Full Text Available The ecosystem-level impacts of the Deepwater Horizon disaster have been largely unpredictable due to the unique setting and magnitude of this spill. We used a five-year (2006-2010 data set within the oil-affected region to explore acute consequences for early-stage survival of fish species inhabiting seagrass nursery habitat. Although many of these species spawned during spring-summer, and produced larvae vulnerable to oil-polluted water, overall and species-by-species catch rates were high in 2010 after the spill (1,989±220 fishes km-towed(-1 [μ ± 1SE] relative to the previous four years (1,080±43 fishes km-towed(-1. Also, several exploited species were characterized by notably higher juvenile catch rates during 2010 following large-scale fisheries closures in the northern Gulf, although overall statistical results for the effects of fishery closures on assemblage-wide CPUE data were ambiguous. We conclude that immediate, catastrophic losses of 2010 cohorts were largely avoided, and that no shifts in species composition occurred following the spill. The potential long-term impacts facing fishes as a result of chronic exposure and delayed, indirect effects now require attention.

  5. Biogenic origin of coalbed gas in the northern Gulf of Mexico Coastal Plain, U.S.A

    Science.gov (United States)

    Warwick, P.D.; Breland, F.C.; Hackley, P.C.

    2008-01-01

    New coal-gas exploration and production in northern Louisiana and south-central Mississippi, Gulf of Mexico Basin, is focused on the Wilcox Group (Paleocene-Eocene), where the depth to targeted subbituminous C to high volatile C bituminous coal beds ranges from 300 to 1680??m, and individual coal beds have a maximum thickness of about 6??m. Total gas content (generally excluding residual gas) of the coal beds ranges from less than 0.37??cm3/g (as-analyzed or raw basis; 1.2??cm3/g, dry, ash free basis, daf) at depths less than 400??m, to greater than 7.3??cm3/g (as-analyzed basis; 8.76??cm3/g, daf) in deeper (> 1,500??m) parts of the basin. About 20 Wilcox coal-gas wells in northern Louisiana produce from 200 to 6485??m3 of gas/day and cumulative gas production from these wells is approximately 25??million m3 (as of December, 2006). U.S. Geological Survey assessment of undiscovered, technically recoverable gas resources in the Gulf of Mexico Coastal Plain, including northern and south-central Mississippi, indicates that coal beds of the Wilcox Group contain an estimated mean total 109.3??million m3 (3.86??trillion ft3) of producible natural gas. To determine the origin of the Wilcox Group coal gases in northern Louisiana, samples of gas, water, and oil were collected from Wilcox coal and sandstone reservoirs and from under- and overlying Late Cretaceous and Eocene carbonate and sandstone reservoirs. Isotopic data from Wilcox coal-gas samples have an average ??13CCH4 value of - 62.6??? VPDB (relative to Vienna Peedee Belemnite) and an average ??DCH4 value of - 199.9??? VSMOW (relative to Vienna Standard Mean Ocean Water). Values of ??13CCO2 range from - 25.4 to 3.42??? VPDB. Produced Wilcox saline water collected from oil, conventional gas, and coalbed gas wells have ??DH2O values that range from - 27.3 to - 18.0??? VSMOW. These data suggest that the coal gases primarily are generated in saline formation water by bacterial reduction of CO2. Shallow (hydrocarbons from

  6. Sedimentary record of recent climate impacts on an insular coastal lagoon in the Gulf of California

    Science.gov (United States)

    Cuellar-Martinez, Tomasa; Ruiz-Fernández, Ana Carolina; Sanchez-Cabeza, Joan-Albert; Alonso-Rodríguez, Rosalba

    2017-03-01

    Sedimentary records are useful to evaluate environmental changes, either from natural or anthropogenic causes, such as global and climate change. The recent changes in accumulation rates and geochemical characteristics (grain size distribution, elemental composition, organic carbon and carbonate concentrations) recorded in a sediment core from San Jose Island Lagoon (SJIL, Gulf of California) were evaluated to determine its relationship with anthropogenic impacts and climatic variability. The 210Pb-derived chronology was corroborated with 239+240Pu and 137Cs stratigraphic markers. The mass accumulation rate increased up to ∼3 times during the past ∼100 years (0.16 ± 0.03 to 0.51 ± 0.06 g cm-2 yr-1). The contents of terrigenous and marine (salinity) indicator elements, as well as fine-grained sediments, also increased considerably, although no anthropization evidences were observed; indeed, the enrichment factor of trace elements indicated that the ecosystem is still a pristine environment. By using multivariate statistical techniques, we inferred that the larger input of fine-grained terrigenous sediments could be related to the enhancement of soil erosion from the catchment, under the influence of higher rainfall rates, especially during the last 20 years. In addition, the higher concentrations of salinity indicator elements most likely resulted from higher evaporation rates in the lagoon, caused by higher minimum atmospheric temperatures. We concluded that recent climate variability has become the main driver for sedimentary geochemical changes in San Jose Island Lagoon. These observations confirmed the usefulness of 210Pb-dated geochemical sediment records to study the impacts of recent climate variability where long-term environmental data is scarce or non-existent.

  7. Tidal hydrodynamics under future sea level rise and coastal morphology in the Northern Gulf of Mexico

    Science.gov (United States)

    Passeri, Davina L.; Hagen, Scott C.; Plant, Nathaniel G.; Bilskie, Matthew V.; Medeiros, Stephen C.; Alizad, Karim

    2016-05-01

    This study examines the integrated influence of sea level rise (SLR) and future morphology on tidal hydrodynamics along the Northern Gulf of Mexico (NGOM) coast including seven embayments and three ecologically and economically significant estuaries. A large-domain hydrodynamic model was used to simulate astronomic tides for present and future conditions (circa 2050 and 2100). Future conditions were simulated by imposing four SLR scenarios to alter hydrodynamic boundary conditions and updating shoreline position and dune heights using a probabilistic model that is coupled to SLR. Under the highest SLR scenario, tidal amplitudes within the bays increased as much as 67% (10.0 cm) because of increases in the inlet cross-sectional area. Changes in harmonic constituent phases indicated that tidal propagation was faster in the future scenarios within most of the bays. Maximum tidal velocities increased in all of the bays, especially in Grand Bay where velocities doubled under the highest SLR scenario. In addition, the ratio of the maximum flood to maximum ebb velocity decreased in the future scenarios (i.e., currents became more ebb dominant) by as much as 26% and 39% in Weeks Bay and Apalachicola, respectively. In Grand Bay, the flood-ebb ratio increased (i.e., currents became more flood dominant) by 25% under the lower SLR scenarios, but decreased by 16% under the higher SLR as a result of the offshore barrier islands being overtopped, which altered the tidal prism. Results from this study can inform future storm surge and ecological assessments of SLR, and improve monitoring and management decisions within the NGOM.

  8. Occurrence of pathogenic Vibrio parahaemolyticus in crustacean shellfishes in coastal parts of Eastern India

    Science.gov (United States)

    Parthasarathy, S.; Das, Suresh Chandra; Kumar, Ashok

    2016-01-01

    Aim: The objective of the study was to isolate and characterize pathogenic Vibrio parahaemolyticus from crustacean shellfishes (crab and shrimp) commonly retailed in coastal parts of eastern India. Materials and Methods: Samples were processed by bacteriological isolation followed by biochemical characterization in Kaper’s medium. Presumptively identified isolates were confirmed by species-specific Vp-toxR polymerase chain reaction (PCR) assay. Virulence and pandemic property of the confirmed V. parahaemolyticus isolates were determined by specific PCR assays. Results: On screening of 167 samples comprising crabs (n=82) and shrimps (n=85) by the standard bacteriological cultural method, V. parahaemolyticus was presumptively identified in 86.6% (71/82) and 82.3% (70/85) of respective samples. Of these, 46 (56%) and 66 (77.6%) isolates from crab and shrimp, respectively, were confirmed as V. parahaemolyticus by biochemical characterization (Kaper’s reaction) followed by specific Vp-toxR PCR assay. About 10 isolates each from crab and shrimp was found to carry the virulence gene (tdh). It denotes that 12.2% of crab and 11.7% of shrimp in the study area are harboring the pathogenic V. parahaemolyticus. Such tdh+ isolates (n=20) were subjected for screening of pandemic genotype by pandemic group specific (PGS) - PCR (PGS-PCR) and GS-PCR (toxRS gene) where 11 (6.5%) isolates revealed the pandemic determining amplicon (235 bp) in PGS-PCR and belonged to crab (7.3%) and shrimp (6%) samples; however, 2 (2.4%) isolates were positive in GS-PCR and belonged to crab samples only. These two GS-PCR+ isolates from crab were also positive in PGS-PCR. Conclusion: The findings of the study conclusively indicated that a considerable percentage of crab and shrimp in these areas were harboring pathogenic and pandemic V. parahaemolyticus posing a public health risk in consumption of improperly processed such shellfishes. Cross contamination of other marine and fresh water market

  9. Assessing the magnitude and significance of deep chlorophyll maxima of the coastal eastern Indian Ocean

    Science.gov (United States)

    Hanson, Christine E.; Pesant, Stéphane; Waite, Anya M.; Pattiaratchi, Charitha B.

    2007-04-01

    previously unrecognized significance of these DCM layers in the coastal eastern Indian Ocean has important implications for satellite-based estimates of production within the region.

  10. Occurrence of pathogenic Vibrio parahaemolyticus in crustacean shellfishes in coastal parts of Eastern India

    Directory of Open Access Journals (Sweden)

    S. Parthasarathy

    2016-03-01

    Full Text Available Abstract Aim: The objective of the study was to isolate and characterize pathogenic Vibrio parahaemolyticus from crustacean shellfishes (crab and shrimp commonly retailed in coastal parts of eastern India. Materials and Methods: Samples were processed by bacteriological isolation followed by biochemical characterization in Kaper’s medium. Presumptively identified isolates were confirmed by species-specific Vp-toxR polymerase chain reaction (PCR assay. Virulence and pandemic property of the confirmed V. parahaemolyticus isolates were determined by specific PCR assays. Results: On screening of 167 samples comprising crabs (n=82 and shrimps (n=85 by the standard bacteriological cultural method, V. parahaemolyticus was presumptively identified in 86.6% (71/82 and 82.3% (70/85 of respective samples. Of these, 46 (56% and 66 (77.6% isolates from crab and shrimp, respectively, were confirmed as V. parahaemolyticus by biochemical characterization (Kaper’s reaction followed by specific Vp-toxR PCR assay. About 10 isolates each from crab and shrimp was found to carry the virulence gene (tdh. It denotes that 12.2% of crab and 11.7% of shrimp in the study area are harboring the pathogenic V. parahaemolyticus. Such tdh+ isolates (n=20 were subjected for screening of pandemic genotype by pandemic group specific (PGS - PCR (PGS-PCR and GS-PCR (toxRS gene where 11 (6.5% isolates revealed the pandemic determining amplicon (235 bp in PGS-PCR and belonged to crab (7.3% and shrimp (6% samples; however, 2 (2.4% isolates were positive in GS-PCR and belonged to crab samples only. These two GS-PCR+ isolates from crab were also positive in PGS-PCR. Conclusion: The findings of the study conclusively indicated that a considerable percentage of crab and shrimp in these areas were harboring pathogenic and pandemic V. parahaemolyticus posing a public health risk in consumption of improperly processed such shellfishes. Cross contamination of other marine and fresh water

  11. Behavior and trends for Zn in Saronikos Gulf

    Directory of Open Access Journals (Sweden)

    Chalkiadakis O.

    2013-04-01

    Full Text Available The study of Zn in the water column of Saronikos Gulf in Greece during a two year period between 2008 and 2010 added data to the available time series of metal data for this marine area since 1985. The Saronikos Gulf, is directly influenced by the Athens metropolitan area. The operation of the Wastewater Treatment Plant of Athens situated on the small island of Psitalia, in 1995, was considered to be the turning point in the efforts of de-pollution of the gulf. Major sources of pollution for the gulf include also the port of Piraeus, with intensive navigation and shipping activities and the significant industrial activity occurring along the coast of Attica. This study of dissolved and particulate Zn gave results consistent with previous studies of the area such as the prevalence of the dissolved form of Zn and the most affected areas being the smaller most enclosed Gulf of Elefsina and Psitalia Island near the wastewater outfall. However, the concentrations of Zn were below toxic levels for marine aquatic organisms. Furthermore, a clear decrease in the Eastern part of the gulf was exhibited as well as a more subtle decrease in the gulf of Elefsina. The levels of Zn in Saronikos Gulf were found comparable to those of other Greek coastal areas.

  12. Multiple regression models of δ13C and δ15N for fish populations in the eastern Gulf of Mexico

    Science.gov (United States)

    Radabaugh, Kara R.; Peebles, Ernst B.

    2014-08-01

    Multiple regression models were created to explain spatial and temporal variation in the δ13C and δ15N values of fish populations on the West Florida Shelf (eastern Gulf of Mexico, USA). Extensive trawl surveys from three time periods were used to acquire muscle samples from seven groundfish species. Isotopic variation (δ13Cvar and δ15Nvar) was calculated as the deviation from the isotopic mean of each fish species. Static spatial data and dynamic water quality parameters were used to create models predicting δ13Cvar and δ15Nvar in three fish species that were caught in the summers of 2009 and 2010. Additional data sets were then used to determine the accuracy of the models for predicting isotopic variation (1) in a different time period (fall 2010) and (2) among four entirely different fish species that were collected during summer 2009. The δ15Nvar model was relatively stable and could be applied to different time periods and species with similar accuracy (mean absolute errors 0.31-0.33‰). The δ13Cvar model had a lower predictive capability and mean absolute errors ranged from 0.42 to 0.48‰. δ15N trends are likely linked to gradients in nitrogen fixation and Mississippi River influence on the West Florida Shelf, while δ13C trends may be linked to changes in algal species, photosynthetic fractionation, and abundance of benthic vs. planktonic basal resources. These models of isotopic variability may be useful for future stable isotope investigations of trophic level, basal resource use, and animal migration on the West Florida Shelf.

  13. Biogeography of thermophilic, endospore-forming bacteria in deepwater hydrocarbon seep sediments of the Eastern Gulf of Mexico

    Science.gov (United States)

    Chakraborty, A.; Hubert, C. R.; Ellefson, E.

    2016-12-01

    Dormant endospores of thermophilic bacteria (thermospores) are routinely detected in permanently cold marine surface sediments and are an example of the microbial rare biosphere. These endospores remain undetected in nucleic-acid based community surveys, but can germinate and proliferate during high-temperature incubations. Prominent genera of thermospores include sulfate-reducing Desulfotomaculum and Pelotomaculum as well as fermentative Caloranaerobacter and Thermicanus, within the phylum Firmicutes. Many thermospores are closely related to microorganisms indigenous to subseafloor petroleum reservoirs. If thermospores found in the cold seabed originate warm subsurface petroleum reservoirs, hydrocarbon seeps are likely natural conduits for their passive dispersal up into the ocean. As such, thermospore distributions in marine sediments might have utility in detection of natural hydrocarbon seeps. Marine surface sediments from 112 locations in the Eastern Gulf of Mexico ranging from 100 to 3300 m water depth and situated 6 to 600 km away from each other were sampled and classified according to geochemical indications of oil seepage. Sediment microcosms amended with 20 mM sulfate and a mixture of organic substrates were pasteurized at 80°C then incubated at 50-55°C for 14 days. Sulfate reduction was monitored and detected in 84 (75%) of the sediment samples. The rate and extent of sulfate reduction at this high temperature was greater in the oil-containing sediments than in the sediments without oil. Sequencing of the V3-V4 region of the 16S rRNA gene on an Illumina MiSeq benchtop sequencer before and after high temperature incubations revealed enrichments of various thermospore genera with the majority being closely related to bacteria previously detected in deep subsurface environments. These results are consistent with the hypothesis that thermospores in the vicinity of hydrocarbon seeps originate from warm deep biosphere habitats.

  14. On the dynamics of low latitude, wide and shallow coastal system: numerical simulations of the Upper Gulf of Thailand

    Science.gov (United States)

    Saramul, Suriyan; Ezer, Tal

    2014-04-01

    A high-resolution (˜1 km horizontal grid and 21 vertical layers) numerical model based on the Princeton Ocean Model (POM) has been used to study the 3D dynamics of the Upper Gulf of Thailand (UGOT). While influenced by tides and rivers like other estuarine systems, the UGOT is unique because it is wide (˜100 km × 100 km), it is shallow (average depth of only ˜15 m), it is located in low latitudes (˜12.5°N-13.5°N), and it is influenced by the seasonal monsoon. Sensitivity studies were thus conducted to evaluate the impact that surface heat fluxes, monsoonal winds, river runoffs, and the low latitude may have on the dynamics; the latter has been evaluated by modifying the Coriolis parameter and comparing simulations representing low and mid latitudes. The circulation in the UGOT changes seasonally from counter-clockwise during the northeast monsoon (dry season) to clockwise during the southwest monsoon (wet season). River discharges generate coastal jets, whereas river plumes tend to be more symmetric near the river mouth and remain closer to the coast in low latitudes, compared with mid-latitude simulations. River plumes are also dispersed along the coast in different directions during different stages of the monsoonal winds. The model results are compared favorably with a simple wind-driven analytical estuarine model. Comparisons between an El Niño year (1998) and a La Niña year (2000) suggest that water temperatures, warmer by as much as 2 °C in 1998 relative to 2000, are largely driven by decrease cloudiness during the El Niño year. The developed model of the UGOT could be used in the future to address various environmental problems affecting the region.

  15. Tidal hydrodynamics in a two-inlet coastal lagoon in the Gulf of California

    Science.gov (United States)

    Serrano, David; Ramírez-Félix, Evlin; Valle-Levinson, Arnoldo

    2013-07-01

    The aim of this study is to understand the effects of friction and advection in the hydrodynamics of a two-inlet coastal lagoon, Santa María La Reforma, in Northwest Mexico. A vertically integrated numerical model is used to describe sea level variations and tidal currents, and to study the dynamics inside the system. Observed sea level and current measurements were used to calibrate the model. Results show a ˜90 min phase lag of the tidal signal in the center of the system with respect to both inlets. Tidal currents greater than 1.0 m s-1 were recorded and modeled at both inlets. The sea level in the lagoon shows one-quarter of period of M2 out of phase (˜3 h) with respect to the velocity. Bottom friction generated the greatest M4 harmonic and largest tidal asymmetries at the narrowest section of the lagoon, ˜35 km away from the inlets. The tidal momentum balance along the main axis of the lagoon was dominated by pressure gradient and friction, describing a quasi-standing tidal wave in currents and in amplitude. This behavior resulted from waves traveling in opposite directions from the two tidal inlets, causing constructive interference in elevation but destructive interference inflow.

  16. Cadmium, copper, lead and zinc in cultured oysters under two contrasting climatic conditions in coastal lagoons from SE Gulf of California, Mexico.

    Science.gov (United States)

    Osuna-Martínez, Carmen C; Páez-Osuna, Federico; Alonso-Rodríguez, Rosalba

    2011-09-01

    In order to determine the metal concentrations in cultured oysters from four coastal lagoons from SE Gulf of California, several individuals of Crassostrea gigas and C. corteziensis were collected and their cadmium, copper, lead and zinc levels were measured by atomic absorption spectrometry after acid digestion. The concentration of metals in oyster soft tissue was Zn > Cu > Cd > Pb. In two lagoons, Cd concentrations (10.1-13.5 μg g(-1) dw) exceeded the maximum level allowed according to the Official Mexican Standard (NOM-031-SSA1-1993), which is equivalent to the WHO recommended Cd levels in organisms used for human consumption.

  17. Mercury in cultured oysters (Crassostrea gigas Thunberg, 1793 and C. corteziensis Hertlein, 1951) from four coastal lagoons of the SE Gulf of California, Mexico.

    Science.gov (United States)

    Osuna-Martínez, C C; Páez-Osuna, F; Alonso-Rodríguez, R

    2010-09-01

    In order to determine the mercury concentrations in cultured oysters from coastal lagoons (SE Gulf of California), several individuals of Crassostrea gigas and C. corteziensis were collected and their mercury levels were measured with a cold vapor analyzer. The mean concentrations during the rainy and dry seasons, respectively, were 0.70 and 0.15 microg g(-1) in C. gigas and 0.56 and 0.18 microg g(-1) in C. corteziensis. During the rainy season, elevated mercury contents are apparently related to terrigen transport from the watershed, while during the dry season, the moderate levels are related to upwellings.

  18. Population Trend and Elasticities of Vital Rates for Steller Sea Lions (Eumetopias jubatus) in the Eastern Gulf of Alaska: A New Life-History Table Analysis.

    Science.gov (United States)

    Maniscalco, John M; Springer, Alan M; Adkison, Milo D; Parker, Pamela

    2015-01-01

    Steller sea lion (Eumetopias jubatus) numbers are beginning to recover across most of the western distinct population segment following catastrophic declines that began in the 1970s and ended around the turn of the century. This study makes use of contemporary vital rate estimates from a trend-site rookery in the eastern Gulf of Alaska (a sub-region of the western population) in a matrix population model to estimate the trend and strength of the recovery across this region between 2003 and 2013. The modeled population trend was projected into the future based on observed variation in vital rates and a prospective elasticity analysis was conducted to determine future trends and which vital rates pose the greatest threats to recovery. The modeled population grew at a mean rate of 3.5% per yr between 2003 and 2013 and was correlated with census count data from the local rookery and throughout the eastern Gulf of Alaska. If recent vital rate estimates continue with little change, the eastern Gulf of Alaska population could be fully recovered to pre-decline levels within 23 years. With density dependent growth, the population would need another 45 years to fully recover. Elasticity analysis showed that, as expected, population growth rate (λ) was most sensitive to changes in adult survival, less sensitive to changes in juvenile survival, and least sensitive to changes in fecundity. A population decline could be expected with only a 6% decrease in adult survival, whereas a 32% decrease in fecundity would be necessary to bring about a population decline. These results have important implications for population management and suggest current research priorities should be shifted to a greater emphasis on survival rates and causes of mortality.

  19. Population Trend and Elasticities of Vital Rates for Steller Sea Lions (Eumetopias jubatus in the Eastern Gulf of Alaska: A New Life-History Table Analysis.

    Directory of Open Access Journals (Sweden)

    John M Maniscalco

    Full Text Available Steller sea lion (Eumetopias jubatus numbers are beginning to recover across most of the western distinct population segment following catastrophic declines that began in the 1970s and ended around the turn of the century. This study makes use of contemporary vital rate estimates from a trend-site rookery in the eastern Gulf of Alaska (a sub-region of the western population in a matrix population model to estimate the trend and strength of the recovery across this region between 2003 and 2013. The modeled population trend was projected into the future based on observed variation in vital rates and a prospective elasticity analysis was conducted to determine future trends and which vital rates pose the greatest threats to recovery. The modeled population grew at a mean rate of 3.5% per yr between 2003 and 2013 and was correlated with census count data from the local rookery and throughout the eastern Gulf of Alaska. If recent vital rate estimates continue with little change, the eastern Gulf of Alaska population could be fully recovered to pre-decline levels within 23 years. With density dependent growth, the population would need another 45 years to fully recover. Elasticity analysis showed that, as expected, population growth rate (λ was most sensitive to changes in adult survival, less sensitive to changes in juvenile survival, and least sensitive to changes in fecundity. A population decline could be expected with only a 6% decrease in adult survival, whereas a 32% decrease in fecundity would be necessary to bring about a population decline. These results have important implications for population management and suggest current research priorities should be shifted to a greater emphasis on survival rates and causes of mortality.

  20. Effects of flooding and drought on water quality in Gulf Coastal Plain streams in Georgia.

    Science.gov (United States)

    Golladay, Stephen W; Battle, Juliann

    2002-01-01

    Since 1994, water-quality constituents have been measured monthly in three adjacent Coastal Plain watersheds in southwestern Georgia. During 1994, rainfall was 650 mm above annual average and the highest flows on record were observed. From November 1998 through November 2000, 19 months had below average rainfall. Lowest flows on record were observed during the summer of 2000. The watersheds are human-dominated with row-crop agriculture and managed forestlands being the major land uses. However, one watershed (Chickasawhatchee Creek) had 10 to 13% less agriculture and greater wetland area, especially along the stream. Suspended particles, dissolved organic carbon, NH4-N, and soluble reactive phosphorus concentrations were greater during wet and flood periods compared with dry and drought periods for each stream. Regional hydrologic conditions had little effect on NO3-N or dissolved inorganic carbon. Chickasawhatchee Creek had significantly lower suspended sediment and NO3-N concentrations and greater organic and inorganic carbon concentrations, reflecting greater wetland area and stronger connection to a regional aquifer system. Even though substantial human land use occurred within all watersheds, water quality was generally good and can be attributed to low stream drainage density and relatively intact floodplain forests. Low drainage density minimizes surface run-off into streams. Floodplain forests reduce nonpoint-source pollutants through biological and physical absorption. In addition to preserving water quality, floodplain forests provide important ecological functions through the export of nutrients and organic carbon to streams. Extreme low flows may be disruptive to aquatic life due to both the lack of water and to the scarcity of biologically important materials originating from floodplain forests.

  1. Late Eocene diatomite from the Peruvian coastal desert, coastal upwelling in the eastern Pacific, and Pacific circulation before the terminal Eocene event

    Energy Technology Data Exchange (ETDEWEB)

    Marty, R.; Dunbar, R.; Martin, J.B.; Baker, P.

    1988-09-01

    Previously undocumented late Eocene diatomaceous sediments are present near Fundo Desbarrancado (FD) in southern Peru. These sediments are similar to Miocene diatomite from the same area but, unlike the Miocene diatomite, the FD sediments contain cherty layers, are enriched in CaCO/sub 3/, have a diverse and abundant radiolarian fauna, and possess varved-massive and millimeter- and meter-scale biogenic-terrigenous alternations. The FD sediments are part of an Eocene sequence that includes the clastic sediments of the Paracas Formation, and they are correlative to the Chira Formation of northern Peru. The Paleogene biogenic sediments of western South America show that coastal upwelling developed in the eastern Pacific before the latest Eocene, argue for the existence of a proto-Humboldt current at this time, and suggest that the terminal Eocene event was the culmination of gradual changes and not a catastrophic event at the Eocene/Oligocene boundary.

  2. Two-way multi-band optical/IR transmisson measurement in the Persian Gulf-coastal region

    NARCIS (Netherlands)

    Jong, A.N. de; Fritz, P.J.

    2005-01-01

    The atmospheric conditions in the Persian Gulf region are significantly different from other places in the world. The particle size distribution may vary daily and during the day. The aerosols can contribute to the amount of rainfall over land, important for the nations around the Gulf. In 2004 NASA

  3. Two-way multi-band optical/IR transmisson measurement in the Persian Gulf-coastal region

    NARCIS (Netherlands)

    Jong, A.N. de; Fritz, P.J.

    2005-01-01

    The atmospheric conditions in the Persian Gulf region are significantly different from other places in the world. The particle size distribution may vary daily and during the day. The aerosols can contribute to the amount of rainfall over land, important for the nations around the Gulf. In 2004 NASA

  4. Comparison of Sea Surface Heights Derived from the Navy Coastal Ocean Model With Satellite Altimetry in the Gulf of Mexico

    Science.gov (United States)

    2008-01-01

    The Gulf of Mexico (GOM) is a semi-enclosed sea that connects in the east to the Atlantic ocean through the straits of Florida, and in the south to...the Caribbean Sea, the Gulf of Mexico , the Straits of Florida, and parts of the western North Atlantic Ocean is the real-time ocean nowcast/forecast

  5. Detailed rock failure susceptibility mapping in steep rocky coasts by means of non-contact geostructural surveys: the case study of the Tigullio Gulf (Eastern Liguria, Northern Italy

    Directory of Open Access Journals (Sweden)

    P. De Vita

    2012-04-01

    Full Text Available In this study, an engineering geological analysis for the assessment of the rock failure susceptibility of a high, steep, rocky coast was developed by means of non-contact geostructural surveys. The methodology was applied to a 6-km coastal cliff located in the Gulf of Tigullio (Northern Tyrrhenian Sea between Rapallo and Chiavari.

    The method is based on the geostructural characterisation of outcropping rock masses through meso- and macroscale stereoscopic analyses of digital photos that were taken continuously from a known distance from the coastline. The results of the method were verified through direct surveys of accessible sample areas. The rock failure susceptibility of the coastal sector was assessed by analysing the fundamental rock slope mechanisms of instability and the results were implemented into a Geographic Information System (GIS.

    The proposed method is useful for rock failure susceptibility assessments in high, steep, rocky coastal areas, where accessibility is limited due to cliffs or steep slopes. Moreover, the method can be applied to private properties or any other area where a complete and systematic analysis of rock mass structural features cannot be achieved.

    Compared to direct surveys and to other non-contact methods based on digital terrestrial photogrammetry, the proposed procedure provided good quality data of the structural features of the rock mass at a low cost. Therefore, the method could be applied to similar coastal areas with a high risk of rock failure occurrence.

  6. Ocean Carbon and Biogeochemistry Scoping Workshop on Terrestrial and Coastal Carbon Fluxes in the Gulf of Mexico, St. Petersburg, FL, May 6-8, 2008

    Science.gov (United States)

    Robbins, L.L.; Coble, P.G.; Clayton, T.D.; Cai, W.J.

    2009-01-01

    Despite their relatively small surface area, ocean margins may have a significant impact on global biogeochemical cycles and, potentially, the global air-sea fluxes of carbon dioxide. Margins are characterized by intense geochemical and biological processing of carbon and other elements and exchange large amounts of matter and energy with the open ocean. The area-specific rates of productivity, biogeochemical cycling, and organic/inorganic matter sequestration are high in coastal margins, with as much as half of the global integrated new production occurring over the continental shelves and slopes (Walsh, 1991; Doney and Hood, 2002; Jahnke, in press). However, the current lack of knowledge and understanding of biogeochemical processes occurring at the ocean margins has left them largely ignored in most of the previous global assessments of the oceanic carbon cycle (Doney and Hood, 2002). A major source of North American and global uncertainty is the Gulf of Mexico, a large semi-enclosed subtropical basin bordered by the United States, Mexico, and Cuba. Like many of the marginal oceans worldwide, the Gulf of Mexico remains largely unsampled and poorly characterized in terms of its air-sea exchange of carbon dioxide and other carbon fluxes. In May 2008, the Ocean Carbon and Biogeochemistry Scoping Workshop on Terrestrial and Coastal Carbon Fluxes in the Gulf of Mexico was held in St. Petersburg, FL, to address the information gaps of carbon fluxes associated with the Gulf of Mexico and to offer recommendations to guide future research. The meeting was attended by over 90 participants from over 50 U.S. and Mexican institutions and agencies. The Ocean Carbon and Biogeochemistry program (OCB; http://www.us-ocb.org/) sponsored this workshop with support from the National Science Foundation, the National Oceanic and Atmospheric Administration, the National Aeronautics and Space Administration, the U.S. Geological Survey, and the University of South Florida. The goal of

  7. Quantifying cross-shelf and vertical nutrient flux in the Coastal Gulf of Alaska with a spatially nested, coupled biophysical model

    Science.gov (United States)

    Hermann, Albert J.; Hinckley, Sarah; Dobbins, Elizabeth L.; Haidvogel, Dale B.; Bond, Nicholas A.; Mordy, Calvin; Kachel, Nancy; Stabeno, Phyllis J.

    2009-12-01

    The Coastal Gulf of Alaska (CGOA) is productive, with large populations of fish, seabirds, and marine mammals; yet it is subject to downwelling-favorable coastal winds. Downwelling regions in other parts of the world are typically much less productive than their upwelling counterparts. Alternate sources of nutrients to feed primary production in the topographically complex CGOA are poorly known and difficult to quantify. Here we diagnose the output from a spatially nested, coupled hydrodynamic and lower trophic level model of the CGOA, to quantify both horizontal and vertical nutrient fluxes into the euphotic zone. Our nested model includes both nitrogen and iron limitation of phytoplankton production, and is driven by a fine-scale atmospheric model that resolves the effects of local orography on the coastal winds. Results indicate significant "rivers" of cross-shelf nitrogen flux due to horizontal advection, as well as "fountains" of vertical transport over shallow banks due to tidal mixing. Using these results, we constructed a provisional budget of nutrient transport among subregions of the CGOA. Contrary to expectations, this budget reveals substantial upwelling of nutrients over major portions of the shelf, driven by local wind-stress curl. These effects are large enough to overwhelm the smaller downwelling flux at the coast throughout the growing season. Vertical mixing by winds and tides, and horizontal flux from the deep basin, are other substantial contributors to nutrients above the 15-m horizon. These findings help to explain the productivity of this coastal ecosystem.

  8. Statistical downscaling of IPCC sea surface wind and wind energy predictions for U.S. east coastal ocean, Gulf of Mexico and Caribbean Sea

    Science.gov (United States)

    Yao, Zhigang; Xue, Zuo; He, Ruoying; Bao, Xianwen; Song, Jun

    2016-08-01

    A multivariate statistical downscaling method is developed to produce regional, high-resolution, coastal surface wind fields based on the IPCC global model predictions for the U.S. east coastal ocean, the Gulf of Mexico (GOM), and the Caribbean Sea. The statistical relationship is built upon linear regressions between the empirical orthogonal function (EOF) spaces of a cross- calibrated, multi-platform, multi-instrument ocean surface wind velocity dataset (predictand) and the global NCEP wind reanalysis (predictor) over a 10 year period from 2000 to 2009. The statistical relationship is validated before applications and its effectiveness is confirmed by the good agreement between downscaled wind fields based on the NCEP reanalysis and in-situ surface wind measured at 16 National Data Buoy Center (NDBC) buoys in the U.S. east coastal ocean and the GOM during 1992-1999. The predictand-predictor relationship is applied to IPCC GFDL model output (2.0°×2.5°) of downscaled coastal wind at 0.25°×0.25° resolution. The temporal and spatial variability of future predicted wind speeds and wind energy potential over the study region are further quantified. It is shown that wind speed and power would significantly be reduced in the high CO2 climate scenario offshore of the mid-Atlantic and northeast U.S., with the speed falling to one quarter of its original value.

  9. Linkages between benthic assemblages and physical environmental factors: The role of geodiversity in Eastern Gulf of Finland ecosystems

    Science.gov (United States)

    Kaskela, A. M.; Rousi, H.; Ronkainen, M.; Orlova, M.; Babin, A.; Gogoberidze, G.; Kostamo, K.; Kotilainen, A. T.; Neevin, I.; Ryabchuk, D.; Sergeev, A.; Zhamoida, V.

    2017-06-01

    We analyzed hydrology, geology and benthic species composition to determine benthic habitat distribution patterns in a geologically complex area of the Gulf of Finland, Northern Baltic Sea. The analysis included several datasets describing coastal influence and geodiversity at multiple spatial scales. Geodiversity in this context refers to variation and/or patchiness of benthic substrates and seabed features. Multivariate statistical methods including BEST and LINKTREE routines were used to identify correlative relationships between different ecological variables. Environmental variables (e.g. water depth, Secchi depth, salinity) were either measured by sampling and remote sensing methods or parameterized from geographic and oceanographic data. Benthic assemblages were assayed by both video recordings and zoobenthic sampling (benthic grabs). Statistical analyses identified correlations between benthic datasets and environmental variables, but correlation parameters were not consistent especially with respect to differing zoobenthic and video-based estimates of benthic diversity. The ratio of Secchi depth to water depth showed strong correlation with species distributions observed in video recordings (ρ = 0.56) whereas variables describing broad-scale geodiversity and archipelago gradient (the abundance of islands, ratio of land and sea area) correlated with zoobenthic sample data (generally ρ > 0.30). A model that included independent variables of Secchi depth and terrain roughness within a 20 km radius explained the greatest proportion of spatial variation in zoobenthic sample data (ρ = 0.69). Secchi depth and roughness values were positively correlated with species richness. We designated nine benthic marine landscapes on the basis of these two variables. Linkage tree statistical analysis (LINKTREE) routine utilized zoobenthic sample data as these offered better regional coverage and therefore effectively tracked relationships with other environmental

  10. Biogenic origin of coalbed gas in the northern Gulf of Mexico Coastal Plain, U.S.A.

    Energy Technology Data Exchange (ETDEWEB)

    Warwick, Peter D.; Hackley, Paul C. [U.S. Geological Survey, 956 National Center, Reston, VA 20192 (United States); Breland, F. Clayton Jr. [Louisiana Department of Natural Resources, 617 North 3rd Street, Baton Rouge, LA 70802 (United States)

    2008-10-02

    New coal-gas exploration and production in northern Louisiana and south-central Mississippi, Gulf of Mexico Basin, is focused on the Wilcox Group (Paleocene-Eocene), where the depth to targeted subbituminous C to high volatile C bituminous coal beds ranges from 300 to 1680 m, and individual coal beds have a maximum thickness of about 6 m. Total gas content (generally excluding residual gas) of the coal beds ranges from less than 0.37 cm{sup 3}/g (as-analyzed or raw basis; 1.2 cm{sup 3}/g, dry, ash free basis, daf) at depths less than 400 m, to greater than 7.3 cm{sup 3}/g (as-analyzed basis; 8.76 cm{sup 3}/g, daf) in deeper (> 1,500 m) parts of the basin. About 20 Wilcox coal-gas wells in northern Louisiana produce from 200 to 6485 m{sup 3} of gas/day and cumulative gas production from these wells is approximately 25 million m{sup 3} (as of December, 2006). U.S. Geological Survey assessment of undiscovered, technically recoverable gas resources in the Gulf of Mexico Coastal Plain, including northern and south-central Mississippi, indicates that coal beds of the Wilcox Group contain an estimated mean total 109.3 million m{sup 3} (3.86 trillion ft{sup 3}) of producible natural gas. To determine the origin of the Wilcox Group coal gases in northern Louisiana, samples of gas, water, and oil were collected from Wilcox coal and sandstone reservoirs and from under- and overlying Late Cretaceous and Eocene carbonate and sandstone reservoirs. Isotopic data from Wilcox coal-gas samples have an average {delta}{sup 13}C{sub CH4} value of - 62.6 permille VPDB (relative to Vienna Peedee Belemnite) and an average {delta}D{sub CH4} value of - 199.9 permille VSMOW (relative to Vienna Standard Mean Ocean Water). Values of {delta}{sup 13}C{sub CO2} range from - 25.4 to 3.42 permille VPDB. Produced Wilcox saline water collected from oil, conventional gas, and coalbed gas wells have {delta}D{sub H2O} values that range from - 27.3 to - 18.0 permille VSMOW. These data suggest that the

  11. Population structure, length-weight and length-length relationships of six populations of the Bartail Flathead Platycephalus indicus (Scorpaeniformes: Platycephalidae along the Persian Gulf coastal waters

    Directory of Open Access Journals (Sweden)

    Hamed Mousavi-Sabet

    2015-01-01

    Full Text Available The size frequency distribution for age structure, length-weight (LWR and length-length (LLR relationships of six populations of Platycephalus indicus along the Persian Gulf coastal waters in Iran are reported.  A total of 180 P. indicus specimens were studied from six localities including Charak, Bandar-Abbas, Shif, Motaf, Khur-Musa and Bahrekan.  The maximum standard length recorded for the studied populations ranged between 300 to 510 mm and the b values of the length-weight relationships ranged between 3.0 and 3.2.  The obtained results indicated isometric growth patterns for all these populations with the exception of the Bahrekan population which showed a positive allometric growth pattern.  The LLR between the total and standard lengths in these populations were found to be highly significant.  The results would be useful for further studies on population assessment and sustainable conservation of the fish along the Persian Gulf coastal waters.

  12. EAARL Coastal Topography--Eastern Florida, Post-Hurricane Jeanne, 2004: Bare Earth

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A digital elevation model (DEM) of a portion of the eastern Florida coastline, post-Hurricane Jeanne (September 2004 hurricane), was produced from remotely sensed,...

  13. EAARL Coastal Topography--Eastern Florida, Post-Hurricane Jeanne, 2004: First Surface

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A digital elevation model (DEM) of a portion of the eastern Florida coastline, post-Hurricane Jeanne (September 2004 hurricane), was produced from remotely sensed,...

  14. EAARL Coastal Topography--Eastern Florida, Post-Hurricane Frances, 2004: First Surface

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A digital elevation map (also known as a Digital Elevation Model, or DEM) of a portion of the eastern Florida coastline was produced from remotely sensed,...

  15. EAARL Coastal Topography--Eastern Florida, Post-Hurricane Frances, 2004: First Surface

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A digital elevation map (also known as a Digital Elevation Model, or DEM) of a portion of the eastern Florida coastline was produced from remotely sensed,...

  16. EAARL Coastal Topography--Eastern Florida, Post-Hurricane Frances, 2004: Bare Earth

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A bare-earth digital elevation map (also known as a Digital Elevation Model, or DEM) of a portion of the eastern Florida coastline was produced from remotely sensed,...

  17. EAARL Coastal Topography--Eastern Louisiana Barrier Islands, Post-Hurricane Gustav, 2008: First Surface

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A digital elevation model (DEM) of a portion of the eastern Louisiana barrier islands, post-Hurricane Gustav (September 2008 hurricane), was produced from remotely...

  18. EAARL Coastal Topography--Eastern Florida, Post-Hurricane Jeanne, 2004: Bare Earth

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A digital elevation model (DEM) of a portion of the eastern Florida coastline, post-Hurricane Jeanne (September 2004 hurricane), was produced from remotely sensed,...

  19. EAARL Coastal Topography--Eastern Florida, Post-Hurricane Jeanne, 2004: First Surface

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A digital elevation model (DEM) of a portion of the eastern Florida coastline, post-Hurricane Jeanne (September 2004 hurricane), was produced from remotely sensed,...

  20. EAARL Coastal Topography--Eastern Louisiana Barrier Islands, Post-Hurricane Gustav, 2008: First Surface

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A digital elevation model (DEM) of a portion of the eastern Louisiana barrier islands, post-Hurricane Gustav (September 2008 hurricane), was produced from remotely...

  1. AFSC/ABL: Eastern Bering Sea (BASIS) Coastal Research on Juvenile Salmon (Oceanography data)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Pacific salmon (Oncorhynchus spp.) runs in rivers that flow into the eastern Bering Sea have been inconsistent and at times very weak. Low returns of chinook (O....

  2. AFSC/ABL: Eastern Bering Sea (BASIS) Coastal Research on Juvenile Salmon (TSG-thermosalinigraph data)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Pacific salmon (Oncorhynchus spp.) runs in rivers that flow into the eastern Bering Sea have been inconsistent and at times very weak. Low returns of chinook (O....

  3. AFSC/ABL: Eastern Bering Sea (BASIS) Coastal Research on Juvenile Salmon

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Pacific salmon (Oncorhynchus spp.) runs in rivers that flow into the eastern Bering Sea have been inconsistent and at times very weak. Low returns of chinook (O....

  4. EAARL Coastal Topography--Eastern Florida, Post-Hurricane Frances, 2004: Bare Earth

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — A bare-earth digital elevation map (also known as a Digital Elevation Model, or DEM) of a portion of the eastern Florida coastline was produced from remotely sensed,...

  5. Reprint of - Deep-sea coral and hardbottom habitats on the west Florida slope, eastern Gulf of Mexico

    Science.gov (United States)

    Ross, Steve W.; Rhode, Mike; Brooke, Sandra

    2017-09-01

    Until recently, benthic habitats dominated by deep-sea corals (DSC) appeared to be less extensive on the slope of the Gulf of Mexico (GOM) than in the northeast Atlantic Ocean or off the southeastern US. There are relatively few bioherms (i.e., coral-built mounds) in the northern GOM, and most DSCs are attached to existing hard substrata (e.g., authigenically formed carbonate). The primary structure-forming, DSC in the GOM is Lophelia pertusa, but structure is also provided by other living and dead scleractinians, antipatharians (black corals), octocorals (gorgonians, soft corals), hydrocorals and sponges, as well as abundant rocky substrata. The best development of DSCs in the GOM was previously documented within Viosca Knoll oil and gas lease blocks 826 and 862/906 (north-central GOM) and on the Campeche Bank (southern GOM in Mexican waters). This paper documents extensive deep reef ecosystems composed of DSC and rocky hard-bottom recently surveyed on the West Florida Slope (WFS, eastern GOM) during six research cruises (2008-2012). Using multibeam sonar, CTD casts, and video from underwater vehicles, we describe the physical and oceanographic characteristics of these deep reefs and provide size or area estimates of deep coral and hardground habitats. The multibeam sonar analyses revealed hundreds of mounds and ridges, some of which were subsequently surveyed using underwater vehicles. Mounds and ridges in <525 m depths were usually capped with living coral colonies, dominated by L. pertusa. An extensive rocky scarp, running roughly north-south for at least 229 km, supported lower abundances of scleractinian corals than the mounds and ridges, despite an abundance of settlement substrata. Areal comparisons suggested that the WFS may exceed other parts of the GOM slope in extent of living deep coral coverage and other deep-reef habitat (dead coral and rock). The complex WFS region warrants additional studies to better understand the influences of oceanography and

  6. Planktonic foraminifera as recorders of sea surface hydrography in the Eastern Tropical North Pacific (Gulf of Tehuantepec, MX)

    Science.gov (United States)

    Gibson, K.; Thunell, R.; Machain-Castillo, M. L.; Wejnert, K.; Nava-Fernández, X. A.; Rodriguez-Ramírez, A.; Tappa, E.

    2014-12-01

    The Gulf of Tehuanetpec (GoT) (14°-16°N and 92°-96°W) is located in the Eastern Tropical North Pacific, a region that is sensitive to changes in both Atlantic-Pacific water vapor transport as well as changes in ENSO. Within the ETNP, the GoT is unique in that it experiences significant changes in temperature (ΔT = 8-10°C) and salinity (ΔS = 3) associated with seasonal variations in precipitation and wind-driven upwelling. Establishing robust relationships between δ18O and Mg/Ca of foraminiferal calcite to sea surface temperature (SST) and sea surface salinity (SSS) in this region can then be used to study past changes in Atl-Pac water vapor transport and ENSO and how these relate to regional and global climate change. We present here a six year (2006-2012), weekly to biweekly resolved record of paired δ18O-Mg/Ca analyses of the planktonic foraminfer Globigerina bulloides, collected from a sediment trap mooring in the GoT (15° 38.826N, 95° 16.905 W). The G. bulloides δ18O values ranges from -0.14‰ to - 3.98‰, equivalent to ~16°C temperature, or nearly twice the observed instrumental change in SST. To help constrain the temperature influence on the δ18Ocalcite signal, Mg/Ca values were converted to temperature using previously published equations for G. bulloides. In addition, we calculated new equations using the Mg/Ca and satellite SST data. Depending on the calibration equation used, G. bulloides from the GoT show a ~5-8% change in Mg/Ca with temperature, and show generally good agreement with SST, particularly in winter upwelling months. The agreement between SST and Mg/Ca-based temperatures is less robust during the winter months of 2009, when a moderate El Niño year resulted in warmer and fresher surface conditions in the GoT than pervious and following years, indicating a deeper habitat depth for G. bulloides and perhaps reduced upwelling during El Niño conditions.

  7. Histological and morphological aspects of reproduction in the sandbar shark Carcharhinus plumbeus in the U.S. south-eastern Atlantic Ocean and Gulf of Mexico.

    Science.gov (United States)

    Piercy, A N; Murie, D J; Gelsleichter, J J

    2016-05-01

    The reproduction of the sandbar shark Carcharhinus plumbeus in the U.S. south-eastern Atlantic Ocean including the Gulf of Mexico was examined using a combination of histological and morphological characteristics of C. plumbeus collected through fishery-dependent and -independent sampling programmes (n = 1,567). Indices of maturity were constructed using measurements of gonads, reproductive tracts and claspers, and sandbar sharks exhibited 50% maturity sizes of 140 and 148 cm fork length for males and females respectively. Gonado-somatic indices and variation in reproductive tract condition were used to determine seasonal trends in reproduction of mature C. plumbeus. Sandbar sharks have discrete seasonal reproductive cycles in which males produce sperm from January to May with a peak in May and females develop eggs from January to May with ovulation occurring in June. Females were shown to exhibit a >2 year reproductive cycle. Embryonic development was assessed through measurements of masses and lengths of uterine contents. Gestation was 12 months, from July to the following June, with parturition in late June. This research highlights a difference from previously reported data on the periodicity of female reproduction in C. plumbeus in the U.S. south-eastern Atlantic Ocean and Gulf of Mexico, which may have major effects on future C. plumbeus stock management.

  8. Comparative analysis of bacterial community-metagenomics in coastal Gulf of Mexico sediment microcosms following exposure to Macondo oil (MC252)

    KAUST Repository

    Koo, Hyunmin

    2014-09-10

    The indigenous bacterial communities in sediment microcosms from Dauphin Island (DI), Petit Bois Island (PB) and Perdido Pass (PP) of the coastal Gulf of Mexico were compared following treatment with Macondo oil (MC252) using pyrosequencing and culture-based approaches. After quality-based trimming, 28,991 partial 16S rRNA sequence reads were analyzed by rarefaction, confirming that analyses of bacterial communities were saturated with respect to species diversity. Changes in the relative abundances of Proteobacteria, Bacteroidetes and Firmicutes played an important role in structuring bacterial communities in oil-treated sediments. Proteobacteria were dominant in oil-treated samples, whereas Firmicutes and Bacteroidetes were either the second or the third most abundant taxa. Tenericutes, members of which are known for oil biodegradation, were detected shortly after treatment, and continued to increase in DI and PP sediments. Multivariate statistical analyses (ADONIS) revealed significant dissimilarity of bacterial communities between oil-treated and untreated samples and among locations. In addition, a similarity percentage analysis showed the contribution of each species to the contrast between untreated and oil-treated samples. PCR amplification using DNA from pure cultures of Exiguobacterium,  Pseudoalteromonas,  Halomonas and Dyadobacter, isolated from oil-treated microcosm sediments, produced amplicons similar to polycyclic aromatic hydrocarbon-degrading genes. In the context of the 2010 Macondo blowout, the results from our study demonstrated that the indigenous bacterial communities in coastal Gulf of Mexico sediment microcosms responded to the MC252 oil with altered community structure and species composition. The rapid proliferation of hydrocarbonoclastic bacteria suggests their involvement in the degradation of the spilt oil in the Gulf of Mexico ecosystem.

  9. Comparative analysis of bacterial community-metagenomics in coastal Gulf of Mexico sediment microcosms following exposure to Macondo oil (MC252).

    Science.gov (United States)

    Koo, Hyunmin; Mojib, Nazia; Thacker, Robert W; Bej, Asim K

    2014-11-01

    The indigenous bacterial communities in sediment microcosms from Dauphin Island (DI), Petit Bois Island (PB) and Perdido Pass (PP) of the coastal Gulf of Mexico were compared following treatment with Macondo oil (MC252) using pyrosequencing and culture-based approaches. After quality-based trimming, 28,991 partial 16S rRNA sequence reads were analyzed by rarefaction, confirming that analyses of bacterial communities were saturated with respect to species diversity. Changes in the relative abundances of Proteobacteria, Bacteroidetes and Firmicutes played an important role in structuring bacterial communities in oil-treated sediments. Proteobacteria were dominant in oil-treated samples, whereas Firmicutes and Bacteroidetes were either the second or the third most abundant taxa. Tenericutes, members of which are known for oil biodegradation, were detected shortly after treatment, and continued to increase in DI and PP sediments. Multivariate statistical analyses (ADONIS) revealed significant dissimilarity of bacterial communities between oil-treated and untreated samples and among locations. In addition, a similarity percentage analysis showed the contribution of each species to the contrast between untreated and oil-treated samples. PCR amplification using DNA from pure cultures of Exiguobacterium,  Pseudoalteromonas,  Halomonas and Dyadobacter, isolated from oil-treated microcosm sediments, produced amplicons similar to polycyclic aromatic hydrocarbon-degrading genes. In the context of the 2010 Macondo blowout, the results from our study demonstrated that the indigenous bacterial communities in coastal Gulf of Mexico sediment microcosms responded to the MC252 oil with altered community structure and species composition. The rapid proliferation of hydrocarbonoclastic bacteria suggests their involvement in the degradation of the spilt oil in the Gulf of Mexico ecosystem.

  10. Coastal Mapping for Baseline Geoscience Knowledge to Support Community Hazard Assessment and Sustainable Development, Eastern Baffin Island, Nunavut

    Science.gov (United States)

    Forbes, D. L.; Bell, T.; Campbell, D. C.; Cowan, B.; Deering, R. L.; Hatcher, S. V.; Hughes Clarke, J. E.; Irvine, M.; Manson, G. K.; Smith, I. R.; Edinger, E.

    2015-12-01

    Since 2012 we have carried out extensive multibeam bathymetric and backscatter surveys in coastal waters of eastern Baffin Island, supplemented by sub-bottom imaging and coring. Shore-zone surveys have been undertaken in proximity to the communities of Iqaluit and Qikiqtarjuaq, following earlier work in Clyde River. These support benthic habitat mapping, geological exploration, analysis of past and present sea-level trends, and assessment of coastal hazards relating to climate change and seabed instability. Outputs include a seamless topographic-bathymetric digital elevation model (DEM) of extensive boulder-strewn tidal flats in the large tidal-range setting at Iqaluit, supporting analysis of coastal flooding, wave run-up, and sea-ice impacts on a rapidly developing urban waterfront in the context of climate change. Seabed mapping of inner Frobisher Bay seaward of Iqaluit reveals a potential local tsunami hazard in widespread submarine slope failures, the triggers, magnitudes, and ages of which are the subject of ongoing research. In fjords of the Cumberland Peninsula, this project has mapped numerous submerged delta terraces at 19 to 45 m present water depth. These attest to an early postglacial submerged shoreline, displaced by glacial-isostatic adjustment. It rises linearly over a distance of 100 km east to west, where a submerged boulder barricade on a -16 m shoreline was discovered at a proposed port site in Broughton Channel near Qikiqtarjuaq. Palaeotopographic mapping using the multibeam data revealed an enclosed estuarine environment quite different from the present-day open passage swept by tidal currents. At Clyde River, combined seabed and onshore DEMs with geohazard mapping provided foundation data for community assessment and planning under a local knowledge co-production initiative. The geohazard work identified portions of the town-site more vulnerable to both coastal flooding and potential thaw subsidence, while the shallow delta terrace suggested a

  11. Coastal Development of Daugavgrîva Island, Located Near the Gulf of Riga / Rîgas Lîèa Piekrastes Krasta Attîstîba Daugavgrîvas Salâ

    Directory of Open Access Journals (Sweden)

    Bçrtiòa Laura

    2015-12-01

    Full Text Available Natural as well as anthropogenic processes impact greatly sensitive coastal areas all over the world. The spectrum of natural processes involved can be classified as meteorological, geological, marine, and lithodynamic. The Baltic Sea with its Gulf of Riga is an area in which combined sea erosion and accumulation processes, as well as alluvial processes, play significant roles in the coastal development. Major anthropogenic processes include impacts from ports and coastal protection structures, such as Riga Port hydraulic structures, fairway channels and coastal defence items. During summer also additional pressure of recreational activities has increased the effect on the coastal beach. Levelling data, historical cartographical material and beach sedimentary material granulometric analysis were used to describe natural and anthropogenic effects on development of the coastal beach of Daugavgrîva Island.

  12. Concentrations and sources of polycyclic aromatic hydrocarbons in surface coastal sediments of the northern Gulf of Mexico

    National Research Council Canada - National Science Library

    Zucheng Wang; Zhanfei Liu; Kehui Xu; Lawrence M Mayer; Zulin Zhang; Alexander S Kolker; Wei Wu

    2014-01-01

    ...) of the northern Gulf of Mexico. Results PAH concentrations in this region ranged from 100 to 856 ng g-1, with the highest concentrations in Mississippi River mouth sediments followed by marsh sediments and then the...

  13. Is Vibrio fluvialis emerging as a pathogen with epidemic potential in coastal region of eastern India following cyclone Aila?

    Science.gov (United States)

    Bhattacharjee, Subhajit; Bhattacharjee, Sayantani; Bal, Baishali; Pal, Reshmi; Niyogi, Swapan Kumar; Sarkar, Kamalesh

    2010-08-01

    An isolated area with diarrhoea epidemic was explored at Pakhirala village of the Sundarbans, a coastal region of South 24 Parganas district of West Bengal, eastern India. The Pakhirala village was surrounded by other villages affected by a similar epidemic. The affected villages experienced this epidemic following the cyclone Aila, which had hit the coastal region of the Sundarbans in eastern India. In Pakhirala, the situation was the worst. Within a span of six weeks (5 June-20 July 2009), 3,529 (91.2%) of 3,871 residents were affected by watery diarrhoea. Of all the cases (n = 3,529), 918 (26%) were affected by moderate to severe diarrhoea. In other villages, 28,550 (70%) of the 40,786 people were affected; of them, 3,997 (14%) had moderate to severe watery diarrhoea. The attack rate and the severity of the cases were significantly higher in Pakhirala village compared to other affected villages. The laboratory results revealed that Vibrio fluvialis was the predominant pathogen in Pakhirala village (5 of 6 laboratory-confirmed organisms) whereas Vibrio cholerae O1 Ogawa was the predominant pathogen in other villages of Gosaba block (7 of 9 bacteriologically-confirmed organisms). This result indicates that V fluvialis behaves more aggressively than V cholerae O1 in an epidemic situation with a higher attack rate and a different clinical picture. An in-depth study is required to explore its pathogenicity in detail, geographical distribution, and possible control measures, including development of specific vaccine preparation and determination of its efficacy.

  14. g178eg.m77t - MGD77 data file for Geophysical data from field activity G-1-78-EG in Eastern Gulf of Alaska, Glacier Bay from 09/12/1978 to 09/23/1978

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Single-beam bathymetry data along with DGPS navigation data was collected as part of field activity G-1-78-EG in Eastern Gulf of Alaska, Glacier Bay from 09/12/1978...

  15. g178eg.m77t - MGD77 data file for Geophysical data from field activity G-1-78-EG in Eastern Gulf of Alaska, Glacier Bay from 09/12/1978 to 09/23/1978

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Single-beam bathymetry data along with DGPS navigation data was collected as part of field activity G-1-78-EG in Eastern Gulf of Alaska, Glacier Bay from 09/12/1978...

  16. l378eg.m77t - MGD77 data file for Geophysical data from field activity L-3-78-EG in Eastern Gulf of Alaska from 06/22/1978 to 07/04/1978

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Single-beam bathymetry, gravity, and magnetic data along with DGPS navigation data was collected as part of field activity L-3-78-EG in Eastern Gulf of Alaska from...

  17. l677eg.m77t - MGD77 data file for Geophysical data from field activity L-6-77-EG in Eastern Gulf of Alaska from 06/13/1977 to 06/30/1977

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Single-beam bathymetry, gravity, and magnetic data along with DGPS navigation data was collected as part of field activity L-6-77-EG in Eastern Gulf of Alaska from...

  18. l378eg.m77t - MGD77 data file for Geophysical data from field activity L-3-78-EG in Eastern Gulf of Alaska from 06/22/1978 to 07/04/1978

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Single-beam bathymetry, gravity, and magnetic data along with DGPS navigation data was collected as part of field activity L-3-78-EG in Eastern Gulf of Alaska from...

  19. l677eg.m77t - MGD77 data file for Geophysical data from field activity L-6-77-EG in Eastern Gulf of Alaska from 06/13/1977 to 06/30/1977

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Single-beam bathymetry, gravity, and magnetic data along with DGPS navigation data was collected as part of field activity L-6-77-EG in Eastern Gulf of Alaska from...

  20. Observations of inner shelf cross-shore surface material transport adjacent to a coastal inlet in the northern Gulf of Mexico

    Science.gov (United States)

    Roth, Mathias K.; MacMahan, Jamie; Reniers, Ad; Özgökmen, Tamay M.; Woodall, Kate; Haus, Brian

    2017-04-01

    Motivated by the Deepwater Horizon oil spill, the Surfzone and Coastal Oil Pathways Experiment obtained Acoustic Doppler Current Profiler (ADCP) Eulerian and GPS-drifter based Lagrangian ;surface; (wind velocities (r =0.76 in the alongshore and r =0.85 in the cross-shore) at the 95% confidence level, and are 4-7 times larger than theoretical estimates of wind and wave-driven surface flow in an un-stratified water column. Differences in near-surface flow are attributed to the presence of a buoyant river plume forced by winds from passing extratropical storms. Plume boundary fronts induce a horizontal velocity gradient where drifters deployed outside of the plume in oceanic water routinely converge, slow, and are re-directed. When the plume flows west parallel to the beach, the seaward plume boundary front acts as a coastal barrier that prevents 100% of oceanic drifters from beaching within 27 km of the inlet. As a result, small-scale, wind-driven river plumes in the northern Gulf of Mexico act as coastal barriers that prevent offshore surface pollution from washing ashore west of river inlets.

  1. Responses of eastern Chinese coastal salt marshes to sea-level rise combined with vegetative and sedimentary processes

    Science.gov (United States)

    Ge, Zhen-Ming; Wang, Heng; Cao, Hao-Bin; Zhao, Bin; Zhou, Xiao; Peltola, Heli; Cui, Li-Fang; Li, Xiu-Zhen; Zhang, Li-Quan

    2016-06-01

    The impacts of sea-level rise (SLR) on coastal ecosystems have attracted worldwide attention in relation to global change. In this study, the salt marsh model for the Yangtze Estuary (SMM-YE, developed in China) and the Sea Level Affecting Marshes Model (SLAMM, developed in the U.S.) were used to simulate the effects of SLR on the coastal salt marshes in eastern China. The changes in the dominant species in the plant community were also considered. Predictions based on the SLAMM indicated a trend of habitat degradation up to 2100; total salt marsh habitat area continued to decline (4–16%) based on the low-level scenario, with greater losses (6–25%) predicted under the high-level scenario. The SMM-YE showed that the salt marshes could be resilient to threats of SLR through the processes of accretion of mudflats, vegetation expansion and sediment trapping by plants. This model predicted that salt marsh areas increased (3–6%) under the low-level scenario. The decrease in the total habitat area with the SMM-YE under the high-level scenario was much lower than the SLAMM prediction. Nevertheless, SLR might negatively affect the salt marsh species that are not adapted to prolonged inundation. An adaptive strategy for responding to changes in sediment resources is necessary in the Yangtze Estuary.

  2. Population genetics of invasive common carp Cyprinus carpio L. in coastal drainages in eastern Australia.

    Science.gov (United States)

    Haynes, G D; Gilligan, D M; Grewe, P; Moran, C; Nicholas, F W

    2010-10-01

    The common carp Cyprinus carpio introduced in two drainages in eastern Australia are largely descended from European common carp, and in a third drainage they descend largely from East Asian common carp. The partial genetic differentiation among the species in those drainages is consistent with their origins.

  3. Improved Oil Recovery from Upper Jurassic Smackover Carbonates through the Application of Advanced Technologies at Womack Hill Oil Field, Choctaw and Clarke Counties, Eastern Gulf Costal Plain

    Energy Technology Data Exchange (ETDEWEB)

    Ernest A. Mancini

    2006-05-31

    Pruet Production Co. and the Center for Sedimentary Basin Studies at the University of Alabama, in cooperation with Texas A&M University, Mississippi State University, University of Mississippi, and Wayne Stafford and Associates proposed a three-phase, focused, comprehensive, integrated and multidisciplinary study of Upper Jurassic Smackover carbonates (Class II Reservoir), involving reservoir characterization and 3-D modeling (Phase I) and a field demonstration project (Phases II and III) at Womack Hill Field Unit, Choctaw and Clarke Counties, Alabama, eastern Gulf Coastal Plain. Phase I of the project has been completed. The principal objectives of the project are: increasing the productivity and profitability of the Womack Hill Field Unit, thereby extending the economic life of this Class II Reservoir and transferring effectively and in a timely manner the knowledge gained and technology developed from this project to producers who are operating other domestic fields with Class II Reservoirs. The major tasks of the project included reservoir characterization, recovery technology analysis, recovery technology evaluation, and the decision to implement a demonstration project. Reservoir characterization consisted of geoscientific reservoir characterization, petrophysical and engineering property characterization, microbial characterization, and integration of the characterization data. Recovery technology analysis included 3-D geologic modeling, reservoir simulation, and microbial core experiments. Recovery technology evaluation consisted of acquiring and evaluating new high quality 2-D seismic data, evaluating the existing pressure maintenance project in the Womack Hill Field Unit, and evaluating the concept of an immobilized enzyme technology project for the Womack Hill Field Unit. The decision to implement a demonstration project essentially resulted in the decision on whether to conduct an infill drilling project in Womack Hill Field. Reservoir performance

  4. Reconstruction of the coastal morphodynamics of the Fulong-beach dune field in north-eastern Taiwan

    Science.gov (United States)

    Dörschner, Nina; Böse, Margot; Frechen, Manfred

    2010-05-01

    The Fulong-beach dune field is located at the north-eastern coast of Taiwan. Built up of medium and fine grained quartz rich sand, it represents a unique feature of only few kilometres along the east coast of Taiwan. This unique sedimentological regime makes the area most perfectly suitable for age estimations by optically stimulated luminescence (OSL). The dune field is crossed by the Shuangsi-river, which flows into the Pacific Ocean. The coastal area is subjected to very dynamic conditions in the transition zone between land and sea. Due to the constant force of marine and aeolian processes from tides, weather and sediment accumulation by rivers, it is a continuously changing area. Taiwan is located in a very active tectonic zone with high elevation rates, which reach from 4 mm per year at the east coast up to 7 mm per year in the southern parts of the island. Furthermore Taiwan is affected by medial 3.8 typhoons per year and minor earthquakes nearly occur every day (LIN ET AL. 2006). The consequences are high rates of erosion and sediment transport during very short time periods. The Fulong-beach coastal area is densely populated and proud for being a tourism destination. At the northern end of the dune field the Lungmen nuclear power plant is currently under construction. Four separate dune ridges could be identified from a digital elevation model and from field mapping. During the field campaign in October and November 2009 17 samples were taken for OSL-dating (MURRAY ET AL. 1995) out of the four dune ridges as well as out of a more than 30 m high elevated outcrop cut by the Shuangsi-river. The measurement and the evaluation of the OSL-samples will provide us an insight into the duration and intensity of the processes affecting the coastal area of Taiwan during the Holocene. We will give an outline during the poster presentation of the methodical approach and the morphodynamical processes affecting the Fulong-beach dune field in north-eastern Taiwan

  5. A preliminary study of an eastern Mediterranean coastal ecosystem: Summer Resorts and Benthic ecosystems

    Directory of Open Access Journals (Sweden)

    S. REIZOPOULOU

    2012-12-01

    Full Text Available The present study investigates whether coastal benthic communities are affected by tourist activities along the coast, which persist for a limited time period. The analysis of benthic macrofauna is based on the ecological parameters (quantitative analyses as well as on the ecological identity of the species (qualitative analyses. Microbial contamination and some population statistics are correlated with ecological parameters. The disturbance of benthic communities in the vicinity of summer resorts is summarized by a reduction in species number and dominance of opportunistic species characteristic of disturbed and polluted environments. It is found that community diversity and evenness of distribution decrease with the deterioration of water quality, expressed as grade of microbial contamination, which implies that benthic community is also a significant element in assessing the quality of coastal waters. The above parameters were statistically negatively correlated with the number of tourists.

  6. Geochemistry of coastal sands of Eastern Mediterranean: The case of Nisyros volcanic materials

    DEFF Research Database (Denmark)

    Tzifas, I.T.; Misaelides, P.; Godelitsas, A.

    2017-01-01

    Coastal sand samples collected from the northern part of Nisyros volcanic island (Dodecanese, Greece) were investigated for first time for their potential in strategic metals and compared with parental rocks of the island which are Quaternary volcanics with alternating lava flows, pyroclastic...... layers and lava domes and relevant materials located near granitoids of Northern Greece. The PXRD and SEM-EDS study of the sands revealed enhanced content of feldspars, Fe-Mn oxides, magnetite, tourmaline, pyroxenes, ilmenites, along with zircons, apatite and sulfide inclusions. The fresh hydrothermally...... (mainly ilmenite), and strategic metals including V (1920 mg/kg) and Nb (245 mg/kg), in the coastal sand. The low REE concentration(ΣREE + Y = 240 mg/kg) could be attributed to the absence of REE-rich minerals. Moreover, the sandsexhibit different geochemical patterns compared to the volcanic source rocks...

  7. The influence of extreme winds on coastal oceanography and its implications for coral population connectivity in the southern Arabian Gulf.

    Science.gov (United States)

    Cavalcante, Geórgenes H; Feary, David A; Burt, John A

    2016-04-30

    Using long-term oceanographic surveys and a 3-D hydrodynamic model we show that localized peak winds (known as shamals) cause fluctuation in water current speed and direction, and substantial oscillations in sea-bottom salinity and temperature in the southern Persian/Arabian Gulf. Results also demonstrate that short-term shamal winds have substantial impacts on oceanographic processes along the southern Persian/Arabian Gulf coastline, resulting in formation of large-scale (52 km diameter) eddies extending from the coast of the United Arab Emirates (UAE) to areas near the off-shore islands of Iran. Such eddies likely play an important role in transporting larvae from well-developed reefs of the off-shore islands to the degraded reef systems of the southern Persian/Arabian Gulf, potentially maintaining genetic and ecological connectivity of these geographically distant populations and enabling enhanced recovery of degraded coral communities in the UAE.

  8. Biomonitoring of arsenic through mangrove oyster (Crassostrea corteziensis Hertlein, 1951) from coastal lagoons (SE Gulf of California): occurrence of arsenobetaine and other arseno-compounds.

    Science.gov (United States)

    Bergés-Tiznado, Magdalena E; Páez-Osuna, Federico; Notti, Alessandra; Regoli, Francesco

    2013-09-01

    In this study, we examined the bioavailability of arsenic through the mangrove oyster Crassostrea corteziensis sampled from seven coastal lagoons in SE Gulf of California during the rainy and dry seasons. As concentrations in soft tissue of oysters C. corteziensis fluctuated between 5.2 and 11.6 μg/g on dry weight; organisms from the control site presented the lowest As concentrations in the two sampling seasons. As speciation was evaluated in selected samples and indicated that arsenobetaine was the major arseno-compound accounting for 53.5-74.7 % of total As. Lower percentage contributions were obtained for nonextractable As (9.7-25.5 %) and other molecules such as arsenocholine and methyl-arsonate (Mexico and indicate that C. corteziensis is safe for human consumption in terms of arseno-compounds. It is evident that As bioavailability in these lagoons is low.

  9. Arsenic and arsenic species in cultured oyster (Crassostrea gigas and C. corteziensis) from coastal lagoons of the SE Gulf of California, Mexico.

    Science.gov (United States)

    Bergés-Tiznado, Magdalena E; Páez-Osuna, Federico; Notti, Alessandra; Regoli, Francesco

    2013-01-01

    The aim of this study was to evaluate the bioavailability of arsenic (As) through cultured oyster Crassostrea gigas and Crassostrea corteziensis from four coastal lagoons (SE Gulf of California). Organisms were collected in two seasons (rainy and dry season), and they were analyzed for total arsenic and chemical speciation of this element. The concentrations of As in oyster soft tissue fluctuated between 5.44 and 9.56 μg/g for rainy season and 6.46 and 8.33 μg/g for dry season (dry weight) in C. gigas. In C. corteziensis, the As concentrations were Mexico and indicate that C. gigas and C. corteziensis farmed in this area are safe for human consumption in terms of arseno-compounds.

  10. Influence of Fouling Assemblage on the Corrosion Behaviour of Mild Steel in the Coastal Waters of The Gulf of Mannar, India

    Institute of Scientific and Technical Information of China (English)

    G. Subramanian; S. Palanichamy

    2013-01-01

    Corrosion behaviour and biofouling characteristics of mild steel in three different coastal locations in the Gulf of Mannar, India have been studied over a period of 24 months. Oyster fouling was predominant at Open sea - Tuticorin, while barnacle fouling was dominant at both Mandapam and Harbour-Tuticorin. The rate of corrosion for 24 months exposure period was highest at Mandapam, where fouling was minimal. The surface of the mild steel was characterized by etchings & crevices beneath the hard foulers attached on it, at all the test locations. The depth of crevice caused by hard foulers was higher at Open sea-Tuticorin followed by Harbour-Tuticorin and Mandapam. The loss in ultimate tensile strength was more in Open sea - Tuticorin than the other two locations. Corrosion behaviour of mild steel is discussed based on the variation in the biofouling assemblage at the three test locations.

  11. Sedimentological and paleontological features of sea floor sediments of Penta Palummo and Miseno volcanic highs, Gulf od Naples (South-eastern Tyrrhenian Sea)

    Energy Technology Data Exchange (ETDEWEB)

    Ferraro, L.; Molisso, F. [Consiglio Nazionale delle Ricerche, Naples (Italy). Ist. di Ricerca Geomare Sud

    2000-07-01

    A sedimentological and paleontological study has been carried out on surficial sediments of Penta Palummo and Miseno volcanic banks, in the Gulf of Naples (South-eastern Tyrrhenian Sea, Italy). The deposits consist of bioclastic sand (coralline algae, bryozoans, gastropods, bivalvs and echinoderms). The benthic foraminiferal assemblage is mainly characterized by epiphytic species. Bioclastics sand is autochtonous and derived from breakdown of algal buildups. [Italian] Uno studio sedimentologico e paleontologico e' stato condotto sui sedimenti superficiali dei banchi vulcanici di Penta Palummo e di Miseno (Golfo di Napoli, Mar Tirreno sudorientale). I depositi sono costituiti da sabbie bioclastiche (alghe coralline, briozoi, gasteropodi, bivalvi ed echonodermi). L'associazione a foraminiferi bentonici e' caratterizzata principalmente da specie epifite. Le sabbie bioclastiche sono autoctone e derivano dal disfacimento di biocostruzioni algali.

  12. Benthic nepheloid layers in the Gulf of Maine and Alexandrium cyst inventories

    Science.gov (United States)

    Pilskaln, C. H.; Hayashi, K.; Keafer, B. A.; Anderson, D. M.; McGillicuddy, D. J.

    2014-05-01

    Cysts residing in benthic nepheloid layers (BNLs) documented in the Gulf of Maine have been proposed as a possible source of inoculum for annual blooms of a toxic dinoflagellate in the region. Herein we present a spatially extensive data set of the distribution and thickness of benthic nepheloid layers in the Gulf of Maine and the abundance and inventories of suspended Alexandrium fundyense cysts within these near-bottom layers. BNLs are pervasive throughout the gulf and adjacent Bay of Fundy with maximum layer thicknesses of 50-60 m observed. Mean BNL thickness is 30 m in the eastern gulf and Bay of Fundy, and 20 m in the western gulf. Cyst densities in the near-bottom particle resuspension layers varied by three orders of magnitude across the gulf with maxima of 105 cysts m-3. An important interconnection of elevated BNL cyst densities is observed between the Bay of Fundy, the Maine Coastal Current and the south-central region of the gulf. BNL cyst inventories estimated for the eastern and western gulf are each on the order of 1015 cysts, whereas the BNL inventory in the Bay of Fundy is on the order of 1016. Although BNL cyst inventories in the eastern and western gulf are 1-2 orders of magnitude smaller than the abundance of cysts in the upper 1 cm of sediment in those regions, BNL and sediment-bound cyst inventories are comparable in the Bay of Fundy. The existence of widespread BNLs containing substantial cyst inventories indicates that these near-bottom layers represent an important source of germinating A. fundyense cysts in the region.

  13. Implications from vitrinite reflectance in two profiles of Coastal Range, Eastern Taiwan

    Science.gov (United States)

    Lih Kae, Chim; Loung-Yie, Tsai; Chung-Pai, Chang; Horng-Yen, Yen; Jiun-Yee, Yen; Ying-San, Liou

    2013-04-01

    Taiwan orogeny was formed by the oblique collision of Luzon arc with the Eurasian continent. The collision started from north and propagated to south. The eroded sediments from Taiwan Orogeny dispersed at adjacent fore arc basin areas. Clay mineralogy and illite crystallinity measurements in Madagida section, southern coastal range indicate illite/smectite decrease and illite crystallinity increase gradationally from old lower section to young upper section. This phenomenon can not record the in-situ burial temperature only reflect the materials being derived from Taiwan central range to adjacent basins. In this study, we try to measure the mudstones samples collected from other sections in coastal range. We chose two profile, Fengpin section and Loho section fore study. These two sections located in northern and central coastal range respectively, 10 and 11 samples were collected for each section. Maceral and carbonaceous materials were extracted do into pellet for measurements of vitrinite reflectance. We use vitrinite reflectance to deduce the basin thermal history. Some sample strata also contain coalified woods and can be analysed to constraint the in-situ burial thermal record. In Loho section, the older Pliocene Fanshuliao Formation samples decrease gradationally to younger whereas the Pleistocene Paliwan Formation samples increase gradationally vitrinite reflectance upward. Beside the younger Pleistocene strata, the Lichi Mélange and the normal sedimentary sequence Paliwan and Fanshuliao Formation revealed significant variation in vitrinite reflectance. However in Fengpin section, we found two significant vitrinite reflectance gaps, this two significant gaps imply evidence of faults. The field geological structure measurement and Raman Spectrocopy carbonaceous materials (RSCM) could be good constraints with the vitrinite reflectance data.

  14. Groundwater quality in the Northern Atlantic Coastal Plain aquifer system, eastern United States

    Science.gov (United States)

    Lindsey, Bruce; Belitz, Kenneth

    2017-01-19

    Groundwater provides nearly 50 percent of the Nation’s drinking water. To help protect this vital resource, the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) Project assesses groundwater quality in aquifers that are important sources of drinking water. The Northern Atlantic Coastal Plain aquifer system constitutes one of the important areas being evaluated. One or more inorganic constituents with human-health benchmarks were detected at high concentrations in about 15 percent of the study area and at moderate concentrations in about 17 percent. Organic constituents were not detected at high concentrations in the study area.

  15. The Colombia Current: An Eastern Tropical Pacific Coastal Current, Early Oceanographic Characteristics

    Science.gov (United States)

    Rodriguez-Rubio, E.

    2007-05-01

    Newly gathered hydrographic data from the Colombia Pacific Ocean is combined with remote sensing data to reassess the properties of the costal current named Colombian Current by Wooster (1959). The Colombian Pacific Ocean is located between 84°-76°W and 1°30'-5°N (oceanic zone), 1°30'- 7°N (coastal zone): This area is well-known also like Panama Bight. New hydrographic data were occupied along the Colombian Pacific coast during March of 2006, making 41 stations with measurements of CTD until a maximum depth of 1200 m, depending on the depth of the marine bottom. On the other hand, sea surface temperatures (SST) were obtained from the MODIS-AQUA satellite and sea surface wind speed and wind direction stem from QuickScat, both averaged for March 2006. Hydrographic grid layers necessary to obtain dynamic topography variable were made with objective mapping calculating is not total dynamic height, but the dynamic height between consecutive levels or "thickness". The purpose of this methodology is that in very coastal campaigns it can have a substantial number of stations that do not arrive at the reference level. Finally geostrophic velocity was computed for the Colombian Current area at several layers. The coast was characterized by low salinities due to river runoff in the North zone. The sea surface temperature during the month of March of 2006 was especially low in the oceanic zone, reaching temperatures between 19°C and 24°C.The dynamic topography indicated the presence of a surface coastal current flowing towards the north and a crosscurrent to 400 m of depth never before described. The wind corresponded to the pattern of the wind jet of Panama. During March the ITCZ moves south, drawing the Panama jet across the Isthmus and over the Pacific. Upwelling curl associated with the left (southeast) flank of this jet generates a cyclonic eddy in the Panama Bight and SST cooling in its center. In the Panama Bight, the curl dipole produces a cyclonic circulation

  16. The Temporal Dynamics of Coastal Phytoplankton and Bacterioplankton in the Eastern Mediterranean Sea.

    Directory of Open Access Journals (Sweden)

    Ofrat Raveh

    Full Text Available This study considers variability in phytoplankton and heterotrophic bacterial abundances and production rates, in one of the most oligotrophic marine regions in the world-the Levantine Basin. The temporal dynamics of these planktonic groups were studied in the coastal waters of the southeastern Mediterranean Sea approximately every two weeks for a total of two years. Heterotrophic bacteria were abundant mostly during late summer and midwinter, and were positively correlated with bacterial production and with N2 fixation. Based on size fractionating, picophytoplankton was abundant during the summer, whereas nano-microphytoplankton predominated during the winter and early spring, which were also evident in the size-fractionated primary production rates. Autotrophic abundance and production correlated negatively with temperature, but did not correlate with inorganic nutrients. Furthermore, a comparison of our results with results from the open Levantine Basin demonstrates that autotrophic and heterotrophic production, as well as N2 fixation rates, are considerably higher in the coastal habitat than in the open sea, while nutrient levels or cell abundance are not different. These findings have important ecological implications for food web dynamics and for biological carbon sequestration in this understudied region.

  17. Eutrophication patterns in an eastern Mediterranean coastal lagoon: Vassova, Delta Nestos, Macedonia, Greece

    Directory of Open Access Journals (Sweden)

    S. ORFANIDIS

    2012-12-01

    Full Text Available The results of an intensive monitoring study of main eutrophication parameters in relation to fish farming management, climate and hydrography in the Vassova coastal lagoon (Nestos Delta are presented. The overall aim is to produce basic knowledge in order to contribute to the management of eutrophication of coastal lagoons at local and national levels. Due to extensive spatiotemporal variability of the measured parameters correlation and regression polynomial analysis was used to identify patterns (p<0.05. Freshwater was the main source of nitrate and phosphate in the lagoon. This finding has justified the reduction of freshwater inflow in the past, which, however, has increased mean salinity to 30 PSU and reduced spatial salinity gradients. Maximum nitrate values in winter coincided with adverse climatic and hydrographic conditions (high precipitation, strong NE to E winds and low tide and fish farming management that hinder water circulation. Dissolved phosphorus variability indicated the combination of the external (freshwaters and internal (sediment P-sources. N/P water values indicated nitrogen being the most important nutrient for primary producers throughout the year, except in winter, when phosphorus was the most important nutrient. Practical measures for improving fish farming practices to decrease “eutrophication risk” during winter are suggested. Existing nutrient data from the Vassova and from other Greek lagoons in comparison were also presented and discussed.

  18. Oceanographic profile data collected from CTD casts aboard RA-4 as part of project OPR-P136-RA-14 in the Coastal Waters of SE Alaska and Gulf of Alaska from 2014-05-07 to 2014-11-11 (NCEI Accession 0130664)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0130664 includes physical and profile data collected aboard the RA-4 during project OPR-P136-RA-14 in the Coastal Waters of SE Alaska and Gulf of...

  19. Physical, wind wave spectra, and other data from meteorological sensors, moored buoy casts, thermistors, and accelerometers in fixed locations in the Gulf of Mexico, South Pacific Ocean, Coastal Waters of Western U.S., Great Lakes, North American Coastline-North, and North American Coastline-South from 01 January 2001 to 31 January 2001 (NODC Accession 0000408)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Physical, wind wave spectra, and other data were collected from fixed platforms in the Gulf of Mexico, South Pacific Ocean, Coastal Waters of Western U.S., Great...

  20. Dissolved inorganic carbon, pH, alkalinity, temperature, salinity and other variables collected from discrete sample and profile observations using Alkalinity titrator, CTD and other instruments from ENDEAVOUR, JOHN P. TULLY and PARIZEAU in the Coastal Waters of SE Alaska, Gulf of Alaska and North Pacific Ocean from 1985-02-12 to 2010-06-18 (NODC Accession 0110260)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0110260 includes discrete sample and profile data collected from ENDEAVOUR, JOHN P. TULLY and PARIZEAU in the Coastal Waters of SE Alaska, Gulf of...

  1. Eastern tropical Pacific vegetation response to rapid climate change and sea level rise: A new pollen record from the Gulf of Tehuantepec, southern Mexico

    Science.gov (United States)

    Hendy, I. L.; Minckley, T. A.; Whitlock, C.

    2016-08-01

    A 30,000-year-long pollen record from the Gulf of Tehuantepec, southern Mexico shows the varying influence of air temperature, precipitation and eustatic sea-level rise on changes in coastal and upland vegetation patterns. During the late-glacial period, pine-juniper forests grew in the Sierra Madre del Sur along the Pacific Slope with broadleaf forests present at low elevations. Coastal wetland and riparian vegetation were limited in distribution. Significant cooling associated with Heinrich 1 (17,000-15,000 cal yr BP) resulted in an expansion of pine-juniper woodland. By the time of Bølling-Allerød warming (14,700-13,000 cal yr BP), extensive mangrove forest development was assisted by sea-level rise and reduced precipitation associated with a more southerly position of the Intertropical Convergence Zone (ITCZ) than at present. Concurrently, the expansion of oak into pine woodlands was promoted by warmer conditions than before. Increased summer precipitation in the early Holocene and stabilizing sea levels limited mangrove forests along the coast and allowed mixed conifer and hardwood forest to become more widespread inland. The onset of a more seasonal climate, driven by a weakening of the Mexican monsoon and a southerly shift in ITCZ position led to the establishment of modern open forests of pine and oak after 4300 cal yr BP.

  2. Spatial Point Pattern Analysis of Human Settlements and Geographical Associations in Eastern Coastal China — A Case Study

    Directory of Open Access Journals (Sweden)

    Zhonghao Zhang

    2014-03-01

    Full Text Available Understanding the spatial point pattern of human settlements and their geographical associations are important for understanding the drivers of land use and land cover change and the relationship between environmental and ecological processes on one hand and cultures and lifestyles on the other. In this study, a Geographic Information System (GIS approach, Ripley’s K function and Monte Carlo simulation were used to investigate human settlement point patterns. Remotely sensed tools and regression models were employed to identify the effects of geographical determinants on settlement locations in the Wen-Tai region of eastern coastal China. Results indicated that human settlements displayed regular-random-cluster patterns from small to big scale. Most settlements located on the coastal plain presented either regular or random patterns, while those in hilly areas exhibited a clustered pattern. Moreover, clustered settlements were preferentially located at higher elevations with steeper slopes and south facing aspects than random or regular settlements. Regression showed that influences of topographic factors (elevation, slope and aspect on settlement locations were stronger across hilly regions. This study demonstrated a new approach to analyzing the spatial patterns of human settlements from a wide geographical prospective. We argue that the spatial point patterns of settlements, in addition to the characteristics of human settlements, such as area, density and shape, should be taken into consideration in the future, and land planners and decision makers should pay more attention to city planning and management. Conceptual and methodological bridges linking settlement patterns to regional and site-specific geographical characteristics will be a key to human settlement studies and planning.

  3. Occurrence, distribution and environmental risk of pharmaceutically active compounds (PhACs) in coastal and ocean waters from the Gulf of Cadiz (SW Spain).

    Science.gov (United States)

    Biel-Maeso, Miriam; Baena-Nogueras, Rosa María; Corada-Fernández, Carmen; Lara-Martín, Pablo A

    2017-08-31

    In this study, we have evaluated the occurrence and distribution of 78 pharmaceuticals in different aquatic marine environments from the Gulf of Cadiz (SW Spain) for the first time. The obtained results revealed that pharmaceuticals were present in seawater at total concentrations ranging 61-2133 and 16-189ngL(-1) in coastal and oceanic transects, respectively. Potential marine pollution hotspots were observed in enclosed or semi-enclosed water bodies (Cadiz Bay), showing concentrations that were one or two orders of magnitude higher than in the open ocean. The presence of these chemicals in local sewage treatment plants (STPs), one of the main contamination sources, was also assessed, revealing total concentrations of up to 23μgL(-1) in effluents. PhACs with the highest detection frequencies and concentrations in the sampling region were analgesics and anti-inflammatories followed by antibiotics in the case of samples from Cadiz Bay or caffeine in oceanic seawater samples. Risk quotients, expressed as ratios between the measured environmental concentration (MEC) and the predicted no-effect concentrations (PNEC) were higher than 1 for two compounds (gemfibrozil and ofloxacin) in effluent of Jerez de la Frontera sewage treatment plant (STP). No high environmental risk was detected in both coastal and oceanic sampling areas, although the information available about the effects of these chemicals on marine biota is still very limited and negative effects on non-target species cannot be discarded. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Three decadal inputs of total organic carbon from four major coastal river basins to the summer hypoxic zone of the Northern Gulf of Mexico.

    Science.gov (United States)

    He, Songjie; Xu, Y Jun

    2015-01-15

    This study investigated long-term (1980-2009) yields and variability of total organic carbon (TOC) from four major coastal rivers in Louisiana entering the Northern Gulf of Mexico where a large-area summer hypoxic zone has been occurring since the middle 1980s. Two of these rivers drain agriculture-intensive (>40%) watersheds, while the other two rivers drain forest-pasture dominated (>50%) watersheds. The study found that these rivers discharged a total of 13.0×10(4)t TOC annually, fluctuating from 5.9×10(4) to 22.8×10(4)t. Seasonally, the rivers showed high TOC yield during the winter and early spring months, corresponding to the seasonal trend of river discharge. While river hydrology controlled TOC yields, land use has played an important role in fluxes, seasonal variations, and characteristics of TOC. The findings fill in a critical information gap of quantity and quality of organic carbon transport from coastal watersheds to one of the world's largest summer hypoxic zones.

  5. Eastern Gulf of Mexico November 1997 Ocean Currents, Geographic NAD83, MMS (1999) [ocean_currents_egom_Nov_MMS_1997

    Data.gov (United States)

    Louisiana Geographic Information Center — This is one data set of a data package consisting of thirteen point data sets that have as attributes the direction and velocity of ocean currents in the 'eastern'...

  6. Eastern Gulf of Mexico October 1997 Ocean Currents, Geographic NAD83, MMS (1999) [ocean_currents_egom_Oct_MMS_1997

    Data.gov (United States)

    Louisiana Geographic Information Center — This is one data set of a data package consisting of thirteen point data sets that have as attributes the direction and velocity of ocean currents in the 'eastern'...

  7. Eastern Gulf of Mexico January 1997 Ocean Currents, Geographic NAD83, MMS (1999) [ocean_currents_egom_Jan_MMS_1997

    Data.gov (United States)

    Louisiana Geographic Information Center — This is one data set of a data package consisting of thirteen point data sets that have as attributes the direction and velocity of ocean currents in the 'eastern'...

  8. Eastern Gulf of Mexico December 1997 Ocean Currents, Geographic NAD83, MMS (1999) [ocean_currents_egom_Dec_MMS_1997

    Data.gov (United States)

    Louisiana Geographic Information Center — This is one data set of a data package consisting of thirteen point data sets that have as attributes the direction and velocity of ocean currents in the 'eastern'...

  9. Eastern Gulf of Mexico June 1997 Ocean Currents, Geographic NAD83, MMS (1999) [ocean_currents_egom_Jun_MMS_1997

    Data.gov (United States)

    Louisiana Geographic Information Center — This is one data set of a data package consisting of thirteen point data sets that have as attributes the direction and velocity of ocean currents in the 'eastern'...

  10. Eastern Gulf of Mexico April 1997 Ocean Currents, Geographic NAD83, MMS (1999) [ocean_currents_egom_Apr_MMS_1997

    Data.gov (United States)

    Louisiana Geographic Information Center — This is one data set of a data package consisting of thirteen point data sets that have as attributes the direction and velocity of ocean currents in the 'eastern'...

  11. Eastern Gulf of Mexico May 1997 Ocean Currents, Geographic NAD83, MMS (1999) [ocean_currents_egom_May_MMS_1997

    Data.gov (United States)

    Louisiana Geographic Information Center — This is one data set of a data package consisting of thirteen point data sets that have as attributes the direction and velocity of ocean currents in the 'eastern'...

  12. Eastern Gulf of Mexico September 1997 Ocean Currents, Geographic NAD83, MMS (1999) [ocean_currents_egom_Sep_MMS_1997

    Data.gov (United States)

    Louisiana Geographic Information Center — This is one data set of a data package consisting of thirteen point data sets that have as attributes the direction and velocity of ocean currents in the 'eastern'...

  13. Eastern Gulf of Mexico March 1997 Ocean Currents, Geographic NAD83, MMS (1999) [ocean_currents_egom_Mar_MMS_1997

    Data.gov (United States)

    Louisiana Geographic Information Center — This is one data set of a data package consisting of thirteen point data sets that have as attributes the direction and velocity of ocean currents in the 'eastern'...

  14. Eastern Gulf of Mexico August 1997 Ocean Currents, Geographic NAD83, MMS (1999) [ocean_currents_egom_Aug_MMS_1997

    Data.gov (United States)

    Louisiana Geographic Information Center — This is one data set of a data package consisting of thirteen point data sets that have as attributes the direction and velocity of ocean currents in the 'eastern'...

  15. Eastern Gulf of Mexico February 1997 Ocean Currents, Geographic NAD83, MMS (1999) [ocean_currents_egom_Feb_MMS_1997

    Data.gov (United States)

    Louisiana Geographic Information Center — This is one data set of a data package consisting of thirteen point data sets that have as attributes the direction and velocity of ocean currents in the 'eastern'...

  16. Eastern Gulf of Mexico July 1997 Ocean Currents, Geographic NAD83, MMS (1999) [ocean_currents_egom_Jul_MMS_1997

    Data.gov (United States)

    Louisiana Geographic Information Center — This is one data set of a data package consisting of thirteen point data sets that have as attributes the direction and velocity of ocean currents in the 'eastern'...

  17. The presence of the Indo-Pacific symbiont-bearing foraminifer Amphistegina lobifera in Greek coastal ecosystems (Aegean Sea, Eastern Mediterranean

    Directory of Open Access Journals (Sweden)

    M.V. TRIANTAPHYLLOU

    2009-12-01

    Full Text Available During the last decades, hundreds of species of Indo-Pacific origin from the Red Sea have traversed the Suez Canal and settled in the Eastern Mediterranean. Nowadays, Amphistegina lobifera Larsen, is known to be a successful immigrant that is widely distributed in the coastal ecosystems of the Eastern Mediterranean Sea. Amphistegina is the most common epiphytic, symbiont- bearing large foraminifer. In this study we provide additional data on the presence of this species in the coastal ecosystems of Aegean Sea, Greece. The high relative abundance of A. lobifera is the result of very successful adaptation of this species to local conditions and suggests that it has become a significant part of the epiphytic foraminiferal fauna.

  18. A comparative Study of manufacturing industrial Competitiveness in eastern coastal provinces and cities of China based on shift-share analysis model

    Institute of Scientific and Technical Information of China (English)

    Yuan Aizhi

    2009-01-01

    Manufacturing industry is an important symbol which weighs a local economy comprehensive strength and modernized level, and a mighty manufacturing industry is a reliable guarantee which realizes the industry modernization.The manufacturing industry in eastern coastal provinces and cities of China, including Shandong, Jiangsu Zhejiang, Shanghai and Guangdong, holds a quite high proportion, and is competitive.But as to the interior, the manufacturing industry competitiveness of five provinces and cities actually has obviously gradient difference.The concrete profession's competitiveness also has the characteristic respectively.This paper analyzes the competitiveness of manufacturing industry in five provinces and cities by the shift-share analysis, obtains a conclusion that Shandong and Zhejiang have the competitive advantage in the traditional manufacturing industry, that Jiangsu's and Guangdong's competitiveness lies in capital, technology-intensive industry, but that Shanghai manufacturing industry's competitive advantage is not obvious, and then proposes strategy to promote the manufacturing industry in the eastern coastal provinces and cities.

  19. A survey of the coastal vegetation near Port Alfred, eastern Cape

    Directory of Open Access Journals (Sweden)

    R. A. Lubke

    1983-12-01

    Full Text Available Detailed information on the colonization and succession of the sand dunes, dune slacks and rocky outcrops along the coast between the Riet and Kleinemonde Rivers is provided. The main reasons for the paucity of plants on the vast dune system are the movement of sand by wind and the inconsistent rainfall. Zonation of species along a dune transect is not particularly marked although a greater diversity of species is found in the dune slacks where an increased amount of seepage moisture occurs. Reclamation practices in blow-out areas have resulted in a pioneer cover of indigenous plants which should provide dense coastal scrub if the introduced Acacia cyclops is kept under control. Establishment of plants on the rocky promontories has occurred over a very long time and well developed communities and soils have formed. Salt spray and high winds are major controlling factors in the zonation of species along a gradient in this area.

  20. Interaction Between Two Distinct Mesoscale Circulations During Summer in the Coastal Region of Eastern USA

    Science.gov (United States)

    Sims, Aaron P.; Raman, Sethu

    2016-07-01

    The interaction of two phenomena, a sea-breeze front and a thermally-driven local circulation, is investigated during the summer season. The sea-breeze circulation in the coastal Carolinas (USA) can be quite strong and the sea-breeze front often propagates well inland. The Sandhills, an area of sandy soils, is oriented roughly parallel to the coast and is located approximately 180 km inland. Differential heating is a strong driving force for convective development in this coastal region and the Sandhills front develops from the thermally-driven circulation caused by the differential heating of differing soil types. The sea-breeze and the Sandhills circulations have been previously studied independently, however, the interaction of these two phenomena is not well known. A combination of remote sensing, in situ observations, and numerical simulations is used to examine the interaction of these two fronts with remote sensing and in situ observations revealing the differential heating that occurs along the Sandhills region. Radar reflectivity is used to identify the two frontal features that converge and result in enhanced convection. A modelling simulation reveals the vertical structure of the frontal features, their propagation, and interaction, highlighting the interaction of the two fronts that results in enhanced convection between the Sandhills and the coast. Over the Sandhills region, differential heating triggers convective storms. Radar reflectivity and numerical simulation indicate the outflows from these convective storms to produce a shallow Sandhills front that in turn propagates toward the coast. As the two opposing fronts, the Sandhills front and the sea-breeze front, converge and interact, intense convection occurs resulting in additional storms.

  1. Spatial distribution of tuna larvae in the Gulf of Gabes (Eastern Mediterranean in relation with environmental parameters

    Directory of Open Access Journals (Sweden)

    W. KOCHED

    2013-04-01

    Full Text Available Spatial distribution and ecology of the larvae of three tuna species (Thunnus thynnus, Auxis rochei and Euthynnus alletteratus were studied during an ichthyoplankton survey carried out in the Gulf of Gabes (Tunisia in June and July 2009. A total of 80 stations, distributed on a regular sampling grid, were sampled. The main objectives of this survey were to provide information on tuna larvae distribution in the Gulf of Gabes in relation to the environmental parameters. Regarding small tunas, larvae of A. rochei (bullet tuna showed the more widespread distribution, being found at both inshore and offshore stations. E. alletteratus (Atlantic black skipjack larvae were mainly found at the inshore stations covering the wide continental shelf of this region. On the other hand, larvae of the large migratory tuna T. Thynnus (Atlantic bluefin tuna, were mainly recorded at offshore stations, suggesting that spawning possibly takes place mainly near the shelf break. Regarding the biological and physical parameters examined, our results indicate that tuna larvae were mainly collected in oligotrophic and mixed waters resulting from the confluence of surface water of recent Atlantic origin and resident surface Mediterranean waters, as shown by their preference for lower chlorophyll a concentrations (from 1.4 to 2.5 mg m-3 and moderate salinity values (between 37.35 and 37.75. Significantly, tuna larvae seemed to avoid the more eutrophic and saltier waters of the gulf situated very close to the coast and around Kerkennah and Djerba islands.

  2. Spatial distribution of tuna larvae in the Gulf of Gabes (Eastern Mediterranean in relation with environmental parameters

    Directory of Open Access Journals (Sweden)

    W. KOCHED

    2013-03-01

    Full Text Available Spatial distribution and ecology of the larvae of three tuna species (Thunnus thynnus, Auxis rochei and Euthynnus alletteratus were studied during an ichthyoplankton survey carried out in the Gulf of Gabes (Tunisia in June and July 2009. A total of 80 stations, distributed on a regular sampling grid, were sampled. The main objectives of this survey were to provide information on tuna larvae distribution in the Gulf of Gabes in relation to the environmental parameters. Regarding small tunas, larvae of A. rochei (bullet tuna showed the more widespread distribution, being found at both inshore and offshore stations. E. alletteratus (Atlantic black skipjack larvae were mainly found at the inshore stations covering the wide continental shelf of this region. On the other hand, larvae of the large migratory tuna T. Thynnus (Atlantic bluefin tuna, were mainly recorded at offshore stations, suggesting that spawning possibly takes place mainly near the shelf break. Regarding the biological and physical parameters examined, our results indicate that tuna larvae were mainly collected in oligotrophic and mixed waters resulting from the confluence of surface water of recent Atlantic origin and resident surface Mediterranean waters, as shown by their preference for lower chlorophyll a concentrations (from 1.4 to 2.5 mg m-3 and moderate salinity values (between 37.35 and 37.75. Significantly, tuna larvae seemed to avoid the more eutrophic and saltier waters of the gulf situated very close to the coast and around Kerkennah and Djerba islands.

  3. CALCAREOUS NANNOFOSSIL BIOSTRATIGRAPHY OF THE S’ADDE LIMESTONE (MT. ALBO, OROSEI GULF: INSIGHTS INTO THE MIDDLE-LATE JURASSIC EASTERN SARDINIA PASSIVE MARGIN EVOLUTION

    Directory of Open Access Journals (Sweden)

    CRISTINA EMANUELA CASELLATO

    2012-11-01

    Full Text Available Calcareous nannofossil biostratigraphy has been performed on tree sections cropping out in Eastern Sardinia (Orosei Gulf, Mt. Albo. Calcareous nannofossils are rare to few and poorly to moderately preserved. Nevertheless thirteen bioevents have been recognized (S’Adde valley section and a Late Bathonian-Early Tithonian age is derived for the S’Adde Limestone (Lms.. The inferred age constraints, integrated with data from the literature, allow the revision of the S’Adde Lms. chronostratigraphy, and the formalization of the S’Adde Limestone (Dieni & Massari 1985 as a lithostratigraphic unit. Qualitative evaluations of carbonate production/sedimentation rates for the north Mt. Albo area are proposed: the Late Bathonian-Callovian and Oxfordian were times of pronounced reduction of carbonate production/exportation, in agreement with the European passive margin evolution, also affected by starvation fenomena and condensations. A Middle-Late Jurassic basin-and-swell setting related to regional tensional tectonic activity is reconstructed for the north Mt. Albo area. The comparison of new and literature data allows framing the local and Eastern Sardinia passive margin evolution in the broader geodynamic and paleogeographic context of the southern European margin. 

  4. A Perspective on Sea Level Rise and Coastal Storm Surge from Southern and Eastern Africa: A Case Study Near Durban, South Africa

    Directory of Open Access Journals (Sweden)

    Derek D. Stretch

    2012-03-01

    Full Text Available Recent coastal storms in southern Africa have highlighted the need for more proactive management of the coastline. Within the southern and eastern African region the availability of coastal information is poor. The greatest gap in information is the likely effects of a combination of severe sea storms and future sea level rise (SLR on the shoreline. This lack of information creates a barrier to informed decision making. This research outlines a practical localized approach to this problem, which can be applied as a first order assessment within the region. In so doing it provides a cost effective and simple decision support tool for the built environment and disaster professionals in development and disaster assessments. In a South African context the newly promulgated Integrated Coastal Management Act requires that all proposed coastal developments take into consideration future SLR, however such information currently does not exist, despite it being vital for informed planning in the coastal zone. This practical approach has been applied to the coastline of Durban, South Africa as a case study. The outputs are presented in a Geographic Information System (GIS based freeware viewer tool enabling ease of access to both professionals and laypersons. This demonstrates that a simple approach can provide valuable information about the current and future risk of flooding and coastal erosion under climate change to buildings, infrastructure as well as natural features along the coast.

  5. Isotopic characteristics of shells Mytilus galloprovincialis from eastern coastal area of Adriatic Sea

    Directory of Open Access Journals (Sweden)

    Tjaša Kanduč

    2006-06-01

    Full Text Available Samples of Mytilus galloprovincialis were collected from entire Eastern Adriatic coast to determine δ18O and δ13C performed on calcite and aragonite shell layers. The aim of this work was to check whether shells of M. galloprovincialis are good environmental indicators (water temperature, salinity. Based on measured isotopic composition of oxygen in shell layers and assumed isotopic composition in water temperatures of calcite and aragonite of shell layers were calculated. The calculated temperatures for M. galloprovincialis shell growth of calcite and aragonite shell layer are in good agreement with measured temperatures of sea water. According to our results of δ18O and δ13C in shell layers we canseparate the locations of the investigated area into three groups: those with more influence of fresh water, those with less influence of fresh water and those of marine environments.

  6. Species Profiles. Life Histories and Environmental Requirements of Coastal Fishes and Invertebrates (Gulf of Mexico). WHITE SHRIMP.

    Science.gov (United States)

    1984-09-01

    temperature (15 - 66 mm long) did not fair well in in late spring and summer affect 41-opt salinity in the Laguna Madre , distribution and reduce the size of...distri- Food habits of juvenile marine bution of postlarval brown and white fishes occupying seagrass beds in shrimp near Galveston, Texas , with the...in catches shrimp of the Gulf of Mexico. of juvenile brown and white shrimp Trans. Am. Fish . Soc. 100(3):584- in a Texas estuarine canal. Con- 586

  7. Macrobenthos monitoring in the Gulf of Suez, Egypt

    Institute of Scientific and Technical Information of China (English)

    Mohamed M.El - Komi

    2008-01-01

    The biogeography of macrobenthic communities with large-scale differences in species distribution and abundance was studied along the eastern and western coastal regions of the Gulf of Suez to indicate biodiversity of benthos in relation to the prevailing en-virunmental conditions.In general,benthos have a wide variety of species of mainly polychaet worms,crustaceans,bivalves,and other bottom invertebrates hying in burrows in/or on the sediment surface.Coastal development clearly affects the ecosystem after the construction of coastal projects.The highest values of benthic diversity,evenness,richness and dominance are found at the Gulf of Suez (WG 1,WG 3),Ras Gharib ( WG 7,WG 8) and Ras Shukier (WG 9a) by contrast to others.The abundance of macrobenthic organsims along the coasts of Gulf of Suez can be arranged in the following sequence:other groups (34%) greater than crustaceans (25%) greater than polychaetes (22%) greater than molluscs (17%) greater than echinoderms (2%).The biomass of benthic assemblages at different sampling sites can also be ranked as follows:echinoderms (52%) greater than mol-luscs (27%) greater than crustaceans (16%) greater than polychaetes (2%) greater than other groups (3%).Some benthic groups or species indicated a distinctive correlation to pollution sources in the marine ecosystem which obviously increased in the coastal areas due to the extension of the coastal development.These activities needed regular information to establish database for the biology and distribution of marine benthic communities.The density and diversity of benthos are significantly affected by eu-trophication at Ain Sukhna,whereas the benthos in the open Gulf of Suez do not seem to be adversely affected by pollution.

  8. The relationship between volatile halocarbons and phytoplankton pigments during a Trichodesmium bloom in the coastal eastern Arabian Sea

    Science.gov (United States)

    Roy, Rajdeep; Pratihary, Anil; Narvenkar, Gayatree; Mochemadkar, Sunita; Gauns, Mangesh; Naqvi, S. W. A.

    2011-11-01

    Eukaryotic phytoplankton such as diatoms and prymnesiophytes produce biogenic halocarbons in the ocean that serve as important sources of chlorine and bromine to the atmosphere, but the role of cyanobacteria in halocarbon production is not well established. We studied distributions of chloroform (CHCl 3), carbon tetrachloride (CCl 4), methylene bromide (CH 2Br 2) and bromoform (CHBr 3) in relation to phytoplankton composition, determined from pigment analysis complemented by microscopic examination, for one month in coastal waters of the eastern Arabian that experienced a Trichodesmium bloom that typically occurs during the Spring Intermonsoon season. High concentrations of zeaxanthin (23 μg l -1), alpha beta betacarotene (6 μg l -1) and chlorophyll a (67 μg l -1) were found within the bloom whereas the marker pigment concentrations were low outside the bloom. CHCl 3 and CCl 4 occurred in relatively high concentrations in surface waters whereas CH 2Br 2 and CHBr 3 were restricted to the subsurface layer. Chlorinated halocarbons were positively inter-correlated and with CHBr 3. The observed spatial and temporal trends in brominated compounds appear to be related to the abundance of Trichodesmium although correlations between concentrations of brominated compounds with various marker pigments were poor and statistically non-significant. The results support the existence of multiple sources and sinks of halogenated compounds, which might obscure the relationship between halocarbons and phytoplankton composition.

  9. EAARL-B coastal topography: eastern New Jersey, Hurricane Sandy, 2012: first surface

    Science.gov (United States)

    Wright, C. Wayne; Fredericks, Xan; Troche, Rodolfo J.; Klipp, Emily S.; Kranenburg, Christine J.; Nagle, David B.

    2014-01-01

    These remotely sensed, geographically referenced elevation measurements of lidar-derived first-surface (FS) topography datasets were produced by the U.S. Geological Survey (USGS), St. Petersburg Coastal and Marine Science Center, St. Petersburg, Florida. This project provides highly detailed and accurate datasets for a portion of the New Jersey coastline beachface, acquired pre-Hurricane Sandy on October 26, and post-Hurricane Sandy on November 1 and November 5, 2012. The datasets are made available for use as a management tool to research scientists and natural-resource managers. An innovative airborne lidar system, known as the second-generation Experimental Advanced Airborne Research Lidar (EAARL-B), was used during data acquisition. The EAARL-B system is a raster-scanning, waveform-resolving, green-wavelength (532-nm) lidar designed to map nearshore bathymetry, topography, and vegetation structure simultaneously. The EAARL-B sensor suite includes the raster-scanning, water-penetrating full-waveform adaptive lidar, down-looking red-green-blue (RGB) and infrared (IR) digital cameras, two precision dual-frequency kinematic carrier-phase GPS receivers, and an integrated miniature digital inertial measurement unit, which provide for sub-meter georeferencing of each laser sample. The nominal EAARL-B platform is a twin-engine Cessna 310 aircraft, but the instrument may be deployed on a range of light aircraft. A single pilot, a lidar operator, and a data analyst constitute the crew for most survey operations. This sensor has the potential to make significant contributions in measuring sub-aerial and submarine coastal topography within cross-environmental surveys. Elevation measurements were collected over the survey area using the EAARL-B system. The resulting data were then processed using the Airborne Lidar Processing System (ALPS), a custom-built processing system developed in a NASA-USGS collaboration. ALPS supports the exploration and processing of lidar data in

  10. Prospects of apicultural entrepreneurship in coastal districts of eastern India: a melissopalynological evaluation.

    Science.gov (United States)

    Upadhyay, Debasis; Bhattacharya, Swapan; Ferguson, David K; Bera, Subir

    2014-01-01

    A melissopalynological analysis of fifty-one natural honey samples (twenty four spring, fifteen summer and twelve winter) collected during 2010-2011 from two east-coastal districts (20(0)20/ to 22(0)11/ N, 82(0)39/ to 87(0)01/ E) of Orissa, India was performed. Out of 37 unifloral samples found 25 were contributed by Apis cerana indica, seven by A. dorsata and the remaining five by A. florea. Out of 14 multifloral samples five were contributed by A. cerana indica, five by A. dorsata and the remaining four by A. florea. Principal component analysis confirmed the palynological classification of the unifloral honey samples. Eighty-two bee-plant taxa belonging to forty four families were recovered. The predominant nectariferous taxa of the spring season were Acanthus ilicifolius, Avicennia marina, Bruguiera gymnorrhiza, Cocos nucifera, Eucalyptus globulus, Phoenix paludosa, Pongamia pinnata, Prosopis juliflora, Sonneratia apetala and Syzygium cumini. In the summer the predominant nectariferous taxa were Borassus flabellifer, C. nucifera, E. globulus, Syzygium cumini, Terminalia arjuna, Aegiceras corniculatum, P. paludosa and Sonneratia apetala while those of the winter were Brassica nigra, Coriandrum sativum, Zizyphus jujuba, Alstonia scholaris, E. globulus and Bruguiera gymnorrhiza. Very low (entrepreneurship. This should improve the socio-economic status of the people of this region.

  11. Extreme storms, sea level rise, and coastal change: implications for infrastructure reliability in the Gulf of Mexico

    Science.gov (United States)

    Anarde, K.; Kameshwar, S.; Irza, N.; Lorenzo-Trueba, J.; Nittrouer, J. A.; Padgett, J.; Bedient, P. B.

    2016-12-01

    Predicting coastal infrastructure reliability during hurricane events is important for risk-based design and disaster planning, such as delineating viable emergency response routes. Previous research has focused on either infrastructure vulnerability to coastal flooding or the impact of changing sea level and landforms on surge dynamics. Here we investigate the combined impact of sea level, morphology, and coastal flooding on the reliability of highway bridges - the only access points between barrier islands and mainland communities - during future extreme storms. We forward model coastal flooding for static projections of geomorphic change using ADCIRC+SWAN. First-order parameters that are adjusted include sea level and elevation. These are varied for each storm simulation to evaluate relative impact on the reliability of bridges surrounding Freeport, TX. Simulated storms include both synthetic and historical events, which are classified by intensity using the storm's integrated kinetic energy, a metric for surge generation potential. Reliability is estimated through probability of failure - given wave and surge loads - and time inundated. Findings include that: 1) bridge reliability scales inversely with surge height, and 2) sea level rise reduces bridge reliability due to a monotonic increase in surge height. The impact of a shifting landscape on bridge reliability is more complex: barrier island rollback can increase or decrease inundation times for storms of different intensity due to changes in wind-setup and back-barrier bay interactions. Initial storm surge readily inundates the coastal landscape during large intensity storms, however the draining of inland bays following storm passage is significantly impeded by the barrier. From a coastal engineering standpoint, we determine that to protect critical infrastructure, efforts now implemented that nourish low-lying barriers may be enhanced by also armoring back-bay coastlines and elevating bridge approach

  12. Sea Level Changes And Depositional Environments In The Izmit Gulf, Eastern Marmara Sea, During The Late Glacial-Holocene Period

    Science.gov (United States)

    Cagatay, M. N.; Görür, N.; Polonia, A.; Demirbag, E.; Sakinc, M.; Cormier, M. H.; Capotondi, L.; McHugh, C.; Emre, O.; Eris, K.

    2003-04-01

    Offshore and onshore stratigraphic studies, together with high-resolution shallow seismic reflection profiling and multibeam bathymetric mapping, were carried out in the western and central part of the Izmit Gulf. These studies indicate that the western Gulf Izmit was a fresh water environment as part of the Marmara "lake" during the late glaciation and early deglaciation until ~12 kyr BP, when the Marmara basin was inundated by the Mediterranean waters. Correlation of 14C-dated onshore and offshore stratigraphic units in the western Izmit Gulf indicates that generally coarse late glacial sediments overlie a marked erosion surface formed during the low water level of the Marmara "Lake". These coarse sediments are followed upwards by 10.4-7 kyr BP old transgressive and the late Holocene post-transgression mud units. The bathymetry and subbottom chirp profiles clearly show that the palaeoshoreline of this lake was located at -85 m, having been controlled by the bedrock sill depth of the Çanakkale Strait. Another palaeoshoreline observed -65 m on northern margin of the Western Izmit and Karamürsel basins was probably formed during the Younger Dryas sea-level still stand. The shelf areas during about this time were colonized by bioherms, which were drowned and disappeared after further rise of the sea level. The presence of a -65 m marine paleoshoreline in the Karamürsel basin indicate that the sill restricting this basin to the west was much deeper than its present -55 m level and placed further south. The Gölcük basin restricted by a -38 m sill to its west was not probably flooded by the marine waters until ~10 kyr BP. Onshore alluvial fan deposits include a 10-15 cm. thick layer at 18 m containing a mixture of bones, charcoal, marine shells and brick tiles. This layer, dated at 2875 +-85 yr BP (1049 +-82 BC), is believed to be a possible tsunami deposit.

  13. Early Islamic inter-settlement agroecosystems in coastal sand, Yavneh dunefield, eastern Mediterranean coast, Israel

    Science.gov (United States)

    Roskin, Joel; Taxel, Itamar

    2017-04-01

    This study reveals an attempt to condition agriculture in coastal aeolian sand holding a high water table. Twenty-six small sites, clustering in topographic lows of the Yavneh dunefield, southern Israeli coastal plain, yield surficial Early Islamic finds, and eroded 1-2 m high berms built of grey sand partially covered by parabolic and transverse dunes. Small winter ponds develop by some of the sites. A clay loam 2.5 m beneath the surface retains the water table at a depth of 2.2 m. Between the berms, a 10-50 cm thick grey sand unit dating by OSL to 0.9 ka (11th-12th century AD) underlays a loose aeolian sand cover and overlays sand whose upper parts date to 1.1 ka (9th-10th century AD). The grey unit displays slightly improved fertility (phosphate, potassium, nitrogen and calcium carbonate) in relation to the underlying sand suggesting an anthropogenic enrichment of ash and refuse. Particle size is similar to the sand. Organic carbon and magnetic susceptibility values (0-5 SI) values are quite low (0.4-0.8%) for both units. The artifact assemblage is mixed and comprised of small (<10 cm) pottery sherds, ceramic roof tiles, glass, marble and granite fragments, mosaic tesserae, pottery production waste, iron slag, animal bones, seashells, and coins dated between the 8th and 10th century. The artifacts pre-date the OSL age of the underlying grey sand. The pottery shares many characteristics with the rich ceramic assemblage of nearby inland Yavneh. The establishment of the sites may have been executed by the inhabitants of either Yavneh (or another major inland settlement) or the seashore Muslim military stronghold of Yavneh-Yam (Taxel, 2013). The density of the sites is remarkable compared with the paucity of Byzantine sites in the same region, indicating a distinct spatial pattern that served a specific purpose. The lack of buried artifacts and structures suggests that the sites did not serve for permanent/intensive occupation. The widespread utilization of the rich

  14. Features of autumnal differential coastal cooling in south-eastern Baltic deduced from data of MODIS spectroradiometers

    Science.gov (United States)

    Esiukova, Elena; Chubarenko, Irina

    2013-04-01

    Characteristics of profiles of sea surface temperature (SST) from the coastline to deep sea area in Russian sector of the South-Eastern Baltic Sea during seasonal autumnal cooling are identified using the data of spectroradiometers MODIS Aqua. Time periods are chosen when vertical convection and wind mixing make the upper layer (~ 30-40 m) in deep-sea area practically isothermal, and significant horizontal gradients of temperature/density are formed above shallows and underwater coastal slopes. This picture of differential cooling is formed by the combined action of heat exchange with the atmosphere (which is practically the same in coastal and open areas) and horizontal transport of heat from the sea to the shallow/coastal zone. This allows for estimation of horizontal heat and mass transport between the deep and the coastal area. The images of October-November 2002-2009 were analyzed, corresponding to periods of fast decrease of air temperature (at a rate of 0.86-2.54 °C/day). Significant linear portion in shallow-most paret is found to be a characteristic feature of the profiles, which is detected above all types of slopes (steep, sloping, irregular), reaching 20% to 70% of the length of the slope. Comparative analysis of the characteristics of the observed profiles above different slopes at the same image, and for the same slope at different dates was performed. The actual profiles of SST are compared with several theoretically predicted cases (in the absence of horizontal exchange, in of the quasi-stationary exchange), and the modeling results. Estimations suggest that horizontal gradient of water temperature favours seasonal slide of the cold/dense water along the underwater slopes (cascading) with a fairly high speed, reaching tens of cm/s at the shelf edge in the case of rapid cooling of water above the underwater slopes. Current speed at the end of the slopes may be quite high (8-20 cm/s), but comparable to the known values. On the base of numerical

  15. Blood clams community (Anadara granoasa in The Eastern Coastal Waters of Banyuasin Regency South Sumatera

    Directory of Open Access Journals (Sweden)

    Rini Setianingsih

    2016-04-01

    Full Text Available Abstract: This research aimed to study existence of blood clams population and the environmental factors that affect them. This research was conducted in the coastal waters of Banyuasin in February 2015. The blood clamp sample was collected using Ekman Grab at low tide. From the observation in the research site, the highest population density was 60 ind/m2 with clay substrate texture, while the lowest density was 20 ind/m2 on the dusty clay substrate. Blood clams population was not found on the sand substrate texture station. Morphometric data showed that the blood clam population in the research site, including the medium category with b < 3 growth pattern (allometric negative. The results of PCA analysis proved that the habitat texture and sediment organic habitats were dominant factors besides the chemical physics environmental factors of the waters (temperature, salinity, pH. Keywords: Blood clams, density, morphometric, PCA Abstrak (Indonesian: Penelitian ini bertujuan untuk mempelajari keberadaan populasi kerang-darah dan faktor lingkungan yang mempengaruhinya. Penelitian ini dilakukan di perairan pesisir Banyuasin pada bulan Februari 2015. Sampel kerang-darah diambil dengan mengunakan Ekman Grab pada saat air surut. Dari hasil pengamatan pada lokasi penelitian, kepadatan populasi kerang-darah tertinggi adalah 60 ind/m2 dengan tekstur substrat lempung, sedangkan kepadatan terendah adalah 20 ind/m2 pada substrat lempung berdebu. Populasi kerang-darah tidak ditemukan pada stasiun dengan tekstur substrat pasir. Data morfometrik menunjukan bahwa populasi kerang-darah di lokasi penelitian termasuk kategori sedang dengan pola pertumbuhan b < 3 (allometrik negatif. Hasil analisis PCA membuktikan bahwa tekstur habitat dan bahan organik sedimen merupakan faktor dominan disamping faktor lingkungan fisika kimia perairan (suhu, salinitas, pH. Kata kunci: Kerang-darah, kepadatan, morfometrik, PCA

  16. Assessment of the trophic status of four coastal lagoons and one estuarine delta, eastern Brazil.

    Science.gov (United States)

    Cotovicz Junior, Luiz Carlos; Brandini, Nilva; Knoppers, Bastiaan Adriaan; Mizerkowski, Byanka Damian; Sterza, José Mauro; Ovalle, Alvaro Ramon Coelho; Medeiros, Paulo Ricardo Petter

    2013-04-01

    Anthropogenic eutrophication of aquatic ecosystems continues to be one of the major environmental issues worldwide and also of Brazil. Over the last five decades, several approaches have been proposed to discern the trophic state and the natural and cultural processes involved in eutrophication, including the multi-parameter Assessment of Estuarine Trophic Status (ASSETS) index model. This study applies ASSETS to four Brazilian lagoons (Mundaú, Manguaba, Guarapina, and Piratininga) and one estuarine delta (Paraíba do Sul River), set along the eastern Brazilian coast. The model combines three indices based on the pressure-state-response (PSR) approach to rank the trophic status and forecast the potential eutrophication of a system, to which a final ASSETS grade is established. The lagoons were classified as being eutrophic and highly susceptible to eutrophication, due primarily to their longer residence times but also their high nutrient input index. ASSETS classified the estuary of the Paraíba do Sul river with a low to moderate trophic state (e.g., largely mesotrophic) and low susceptibility to eutrophication. Its nutrient input index was high, but the natural high dilution and flushing potential driven by river flow mitigated the susceptibility to eutrophication. Eutrophication forecasting provided more favorable trends for the Mundaú and Manguaba lagoons and the Paraíba do Sul estuary, in view of the larger investments in wastewater treatment and remediation plans. The final ASSETS ranking system established the lagoons of Mundaú as "moderate," Manguaba as "bad," Guarapina as "poor," and Piratininga as "bad," whereas the Paraíba do Sul River Estuary was "good."

  17. Geology and biology of the "Sticky Grounds", shelf-margin carbonate mounds, and mesophotic ecosystem in the eastern Gulf of Mexico

    Science.gov (United States)

    Locker, Stanley D.; Reed, John K.; Farrington, Stephanie; Harter, Stacey; Hine, Albert C.; Dunn, Shane

    2016-08-01

    Shelf-margin carbonate mounds in water depths of 116-135 m in the eastern Gulf of Mexico along the central west Florida shelf were investigated using swath bathymetry, side-scan sonar, sub-bottom imaging, rock dredging, and submersible dives. These enigmatic structures, known to fisherman as the "Sticky Grounds", trend along slope, are 5-15 m in relief with base diameters of 5-30 m, and suggest widespread potential for mesophotic reef habitat along the west Florida outer continental shelf. Possible origins are sea-level lowstand coral patch reefs, oyster reefs, or perhaps more recent post-lowstand biohermal development. Rock dredging recovered bioeroded carbonate-rock facies comprised of bored and cemented bioclastics. Rock sample components included calcified worm tubes, pelagic sediment, and oysters normally restricted to brackish nearshore areas. Several reef sites were surveyed at the Sticky Grounds during a cruise in August 2010 with the R/V Seward Johnson using the Johnson-Sea-Link II submersible to ground truth the swath-sonar maps and to quantify and characterize the benthic habitats, benthic macrofauna, fish populations, and coral/sponge cover. This study characterizes for the first time this mesophotic reef ecosystem and associated fish populations, and analyzes the interrelationships of the fish assemblages, benthic habitats and invertebrate biota. These highly eroded rock mounds provide extensive hard-bottom habitat for reef invertebrate species as well as essential fish habitat for reef fish and commercially/recreationally important fish species. The extent and significance of associated living resources with these bottom types is particularly important in light of the 2010 Deepwater Horizon oil spill in the northeastern Gulf and the proximity of the Loop Current. Mapping the distribution of these mesophotic-depth ecosystems is important for quantifying essential fish habitat and describing benthic resources. These activities can improve ecosystem

  18. Predicting the retreat and migration of tidal forests along the northern Gulf of Mexico under sea-level rise

    Science.gov (United States)

    Doyle, T.W.; Krauss, K.W.; Conner, W.H.; From, A.S.

    2010-01-01

    Tidal freshwater forests in coastal regions of the southeastern United States are undergoing dieback and retreat from increasing tidal inundation and saltwater intrusion attributed to climate variability and sea-level rise. In many areas, tidal saltwater forests (mangroves) contrastingly are expanding landward in subtropical coastal reaches succeeding freshwater marsh and forest zones. Hydrological characteristics of these low-relief coastal forests in intertidal settings are dictated by the influence of tidal and freshwater forcing. In this paper, we describe the application of the Sea Level Over Proportional Elevation (SLOPE) model to predict coastal forest retreat and migration from projected sea-level rise based on a proxy relationship of saltmarsh/mangrove area and tidal range. The SLOPE model assumes that the sum area of saltmarsh/mangrove habitat along any given coastal reach is determined by the slope of the landform and vertical tide forcing. Model results indicated that saltmarsh and mangrove migration from sea-level rise will vary by county and watershed but greater in western Gulf States than in the eastern Gulf States where millions of hectares of coastal forest will be displaced over the next century with a near meter rise in relative sea level alone. Substantial losses of coastal forests will also occur in the eastern Gulf but mangrove forests in subtropical zones of Florida are expected to replace retreating freshwater forest and affect regional biodiversity. Accelerated global eustacy from climate change will compound the degree of predicted retreat and migration of coastal forests with expected implications for ecosystem management of State and Federal lands in the absence of adaptive coastal management.

  19. 20th century sediment budget trends on the Western Gulf of Lions shoreface (France): An application of an integrated method for the study of sediment coastal reservoirs

    Science.gov (United States)

    Brunel, C.; Certain, R.; Sabatier, F.; Robin, N.; Barusseau, J. P.; Aleman, N.; Raynal, O.

    2014-01-01

    This paper presents a shoreface sediment budget established for the 20th century (1895-1984-2009) along the microtidal wave-dominated coast of the western Gulf of Lions (Languedoc-Roussillon, Mediterranean Sea, SE France). The implementation of a diachronic bathymetric approach, coupled with the definition of sand reservoirs (upper sand unit - USU) by very high-resolution seismic surveys and the results of LiDAR investigations, offers a new means of defining precisely the magnitude and change trends of the sediment budget. The aim of this study is to link the Large Scale Coastal Behaviour (LSCB) of the littoral prism (expressed in terms of shoreface sediment budget, shoreface sediment volume and spatial distribution pattern of cells) to climatic change, river sediment input to the coast, longshore sediment transport distribution, impact of hard coastal defence structures and artificial beach nourishment. The results show a significant reduction of the volume of the western Gulf of Lions littoral prism over 114 years (- 26.1 ± 4.6 × 106 m3). From 1895 to 1984, the overall budget is slightly positive, with a volume estimated at 4.1 ± 3.5 × 106 m3. For 1984-2009, however, the estimated sediment budgets clearly indicate that erosion is dominant over the last 25 years, with a volume loss of - 30.2 ± 4.2 × 106 m3. In relation to the long-term sediment budget and longshore drift pattern, the long-term trend of the USU volume distribution displays strong spatio-temporal contrasts linked to longshore sediment drift, spatial distribution of fluvial sediment inputs and hard engineering structures. Locally, the sedimentary reservoir is significantly eroded within a century (- 80% of USU), since the initial amount present was low and not sustainable. The emphasis is on the importance of considering the volume changes of available sediment reservoirs rather than their losses and gains. Erosion of the Languedoc-Roussillon shoreface is likely to continue in the future due to

  20. Molluscan Fauna in Bang Taboon Mangrove Estuary, Inner Gulf of Thailand: Implications for conservation and sustainable use of coastal resources

    Directory of Open Access Journals (Sweden)

    Premcharoen Siraprapha

    2016-01-01

    Full Text Available Molluscan fauna, dealt with diversity and abundance of gastropods and bivalves in Bang Taboon mangrove estuary, Inner Gulf of Thailand was investigated seasonally. Totally 3,337 individuals, representing 18 species (6 bivalves and 12 gastropods with two dominant species, Assiminea brevicula and Tegillarca granosa. The mean density of overall molluscs was 11.79±0.47 n/m2, recorded in September. The highest value of diversity was 0.78±0.53, recorded in March. The most species-rich and individuals were recorded in the large mudflat within intertidal mangrove zone and formed a distinct community structure in the vegetated area at 15 cm depth. Results from the Analysis of the Similarity (ANOSIM showed a clearly significant difference of species diversity and abundance at different areas, depths and seasons (P = 0.001. Although Bang Taboon estuary is impacted by human activities, the habitat remains an important nursery ground for numerous molluscs including many commercial species. The findings of this study can be taken as a base data that would help maximizing mangrove and fisheries resources conservation and utilization in a sustainable way in Bang Taboon estuary and adjacent areas in the inner Gulf of Thailand.

  1. Coastal Lagoons and Climate Change: Ecological and Social Ramifications in U.S. Atlantic and Gulf Coast Ecosystems

    Directory of Open Access Journals (Sweden)

    Leslie Smith

    2009-06-01

    Full Text Available Lagoons are highly productive coastal features that provide a range of natural services that society values. Their setting within the coastal landscape leaves them especially vulnerable to profound physical, ecological, and associated societal disturbance from global climate change. Expected shifts in physical and ecological characteristics range from changes in flushing regime, freshwater inputs, and water chemistry to complete inundation and loss and the concomitant loss of natural and human communities. Therefore, managing coastal lagoons in the context of global climate change is critical. Although management approaches will vary depending on local conditions and cultural norms, all management scenarios will need to be nimble and to make full use of the spectrum of values through which society views these unique ecosystems. We propose that this spectrum includes pragmatic, scholarly, aesthetic, and tacit categories of value. Pragmatic values such as fishery or tourism revenue are most easily quantified and are therefore more likely to be considered in management strategies. In contrast, tacit values such as a sense of place are more difficult to quantify and therefore more likely to be left out of explicit management justifications. However, tacit values are the most influential to stakeholder involvement because they both derive from and shape individual experiences and beliefs. Tacit values underpin all categories of social values that we describe and can be expected to have a strong influence over human behavior. The articulation and inclusion of the full spectrum of values, especially tacit values, will facilitate and support nimble adaptive management of coastal lagoon ecosystems in the context of global climate change.

  2. Fishery and life history of spot-tail mantis shrimp, Squilla mantis (Crustacea: Stomatopoda, in the Gulf of Cadiz (eastern central Atlantic

    Directory of Open Access Journals (Sweden)

    Yolanda Vila

    2013-03-01

    Full Text Available Squilla mantis is an economically important species that is mainly caught by the Sanlucar de Barrameda bottom trawl fleet in the Gulf of Cadiz (eastern central Atlantic. Annual landings have ranged between 24 t in 1999 and 600 t in 2003, with a mean value of 269 t for the period 1984-2010. Catches have a marked seasonality, peaking in winter and showing the lowest values in summer. Larval abundance was negatively correlated with depth and distance from the coast but positively correlated with sea surface temperature. No correlation with sea surface salinity was found. The highest larval abundance was observed in June at 20-25 m depth, while adults were mostly found at 30-35 m depth. This species is mainly concentrated in the area of influence of the Guadalquivir River but is very scarce in the rest of the study area. The maturation of the ovary and the activity of the sexual accessory glands begin in early winter. The population is age-structured in three year classes and females reach first maturity within the second year class, at 23.7 mm carapace length.

  3. Modified MODIS fluorescence line height data product to improve image interpretation for red tide monitoring in the eastern Gulf of Mexico

    Science.gov (United States)

    Hu, Chuanmin; Feng, Lian

    2017-01-01

    Several satellite-based methods have been used to detect and trace Karenia brevis red tide blooms in the eastern Gulf of Mexico. Some require data statistics and multiple data products while others use a single data product. Of these, the MODIS normalized fluorescence line height (nFLH) has shown its advantage of detecting blooms in waters rich in colored dissolved organic matter, thus having been used routinely to assess bloom conditions by the Florida Fish and Wildlife Conservation Commission (FWC), the official state agency of Florida responsible for red tide monitoring and mitigation. However, elevated sediment concentrations in the water column due to wind storms can also result in high nFLH values, leading to false-positive bloom interpretation. Here, a modified nFLH data product is developed to minimize such impacts through empirical adjustments of the nFLH values using MODIS-derived remote sensing reflectance in the green band at 547 nm. The new product is termed as an algal bloom index (ABI), which has shown improved performance over the original nFLH in both retrospective evaluation statistics and near real-time applications. The ABI product has been made available in near real-time through a Web portal and has been used by the FWC on a routine basis to guide field sampling efforts and prepare for red tide bulletins distributed to many user groups.

  4. Assessing coastal wetland vulnerability to sea-level rise along the northern Gulf of Mexico coast: Gaps and opportunities for developing a coordinated regional sampling network

    Science.gov (United States)

    Osland, Michael J.; Griffith, Kereen T.; Larriviere, Jack C.; Feher, Laura C.; Cahoon, Donald R.; Enwright, Nicholas M.; Oster, David A.; Tirpak, John M.; Woodrey, Mark S.; Collini, Renee C.; Baustian, Joseph J.; Breithaupt, Joshua L.; Cherry, Julia A; Conrad, Jeremy R.; Cormier, Nicole; Coronado-Molina, Carlos A.; Donoghue, Joseph F.; Graham, Sean A.; Harper, Jennifer W.; Hester, Mark W.; Howard, Rebecca J.; Krauss, Ken W.; Kroes, Daniel; Lane, Robert R.; Mckee, Karen L.; Mendelssohn, Irving A.; Middleton, Beth A.; Moon, Jena A.; Piazza, Sarai; Rankin, Nicole M.; Sklar, Fred H.; Steyer, Gregory D.; Swanson, Kathleen M.; Swarzenski, Christopher M.; Vervaeke, William; Willis, Jonathan M; Van Wilson, K.

    2017-01-01

    Coastal wetland responses to sea-level rise are greatly influenced by biogeomorphic processes that affect wetland surface elevation. Small changes in elevation relative to sea level can lead to comparatively large changes in ecosystem structure, function, and stability. The surface elevation table-marker horizon (SET-MH) approach is being used globally to quantify the relative contributions of processes affecting wetland elevation change. Historically, SET-MH measurements have been obtained at local scales to address site-specific research questions. However, in the face of accelerated sea-level rise, there is an increasing need for elevation change network data that can be incorporated into regional ecological models and vulnerability assessments. In particular, there is a need for long-term, high-temporal resolution data that are strategically distributed across ecologically-relevant abiotic gradients. Here, we quantify the distribution of SET-MH stations along the northern Gulf of Mexico coast (USA) across political boundaries (states), wetland habitats, and ecologically-relevant abiotic gradients (i.e., gradients in temperature, precipitation, elevation, and relative sea-level rise). Our analyses identify areas with high SET-MH station densities as well as areas with notable gaps. Salt marshes, intermediate elevations, and colder areas with high rainfall have a high number of stations, while salt flat ecosystems, certain elevation zones, the mangrove-marsh ecotone, and hypersaline coastal areas with low rainfall have fewer stations. Due to rapid rates of wetland loss and relative sea-level rise, the state of Louisiana has the most extensive SET-MH station network in the region, and we provide several recent examples where data from Louisiana’s network have been used to assess and compare wetland vulnerability to sea-level rise. Our findings represent the first attempt to examine spatial gaps in SET-MH coverage across abiotic gradients. Our analyses can be

  5. NOAA Coastal Services Center Coastal Inundation Digital Elevation Model: Philadelphia, Pennsylvania Weather Forecast Office (PHI WFO) and Wakefield, Virginia Weather Forecast Office (AKQ WFO) - Eastern Shore of Maryland

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data were created as part of the National Oceanic and Atmospheric Administration Coastal Services Center's efforts to create an online mapping viewer called...

  6. Fe-Mn nodules associated with hydrocarbon seeps: A new discovery in the Gulf of Cadiz(eastern central Atlantic)

    Institute of Scientific and Technical Information of China (English)

    F. J. González; L. Somoza; R. Lunar; J. Martínez-Frías; J. A. Martín Rubí; T. Torres; J. E. Ortíz; V. Díaz-del-Río

    2007-01-01

    @@ The Gulf of Cadiz is situated geologically at the Gibraltar Arc, the westernmost arc of the Alpine-Himalayan orogenic belt. Based on extensive previous studies that include swath bathymetry, multi-channel and very high-resolution seismic reflection, gravimetry, magnetism, heat flow probes, and underwater photography surveys, more than 500 polymetallic nodules were collected at water depths ranging from 850 to 1000 m, associated with hydrocarbon-derived carbonate chimneys, slabs, and crusts. Nodules show a wide range of sizes, densities, weights and morphologies. Nodules are composed of multiple millimetre-thick layers of Fe and Mn oxyhydroxides surrounding a nucleus composed of Early-Middle Miocene plastic marls, which were expulsed from underlying units by fluid venting. Nodules show a high mean abundance of Fe (39.03%), moderate Mn (5.84%),and low contents of trace metals and REEs compared to the average content of deep-sea polymetallic nodules. They display fast growth rates (av. 2,500 mm Myr-1) which are probably the main cause for the low contents of transition metals.

  7. Fate and Transport of Organic Contaminants in Coastal Marsh Sediments Resulting from the 2010 Gulf Oil Spill

    Science.gov (United States)

    Natter, M.; Keevan, J.; Lee, M.; Keimowitz, A.; Savrda, C.; Son, A.; Okeke, B.; Wang, Y.

    2011-12-01

    The devastating explosion and subsequent sinking of the oil platform Deepwater Horizon at the British Petroleum Macondo-1 well in the Northern Gulf of Mexico on April 20, 2010, released approximately 4.9 million barrels of crude oil into the Gulf before the well was capped on July 15, 2010. Although most light compounds of oil may be easily degraded by natural microbes on the short term, saturated heavy oil (e.g., asphaltenes, resins, polycyclic aromatics, etc.) and those adsorbed by sediments could persist in the environment for decades. The long-term effects of high levels of persistent oil compounds on biogeochemical evolution and ecosystems of salt marshes remain unclear. This research investigates the spatial range and changes in levels of oil and their biogeochemical impacts. A total of ten marsh sampling sites that varied from pristine, non-effected marshes (e.g., Weeks Bay and Wolf Bay, Alabama) to heavily oiled wetlands (e.g., Bay Jimmy and Bayou Dulac, Louisiana) were utilized for this study. Sediment cores, bulk sediments, surface water samples, degraded oil, oiled dead marsh grass, and live marsh grass were collected from these sites in an attempt to study the source, distribution, and evolution of organic compounds and oil present in sediments and pore-waters. Geochemical analyses show alarmingly high organic carbon loads in pore-waters and sediments at heavily contaminated sites months after the influx of oil ceased. Very high levels (10-28%) of total organic carbon (TOC) within the heavily oiled sediments (down to 30 cm) are clearly distinguished from those found in pristine wetland sediments (generally oil dispersants. Furthermore, dissolved organic carbon (DOC) levels of pore-waters extracted from oiled sediments, ranging up to hundreds of mg/kg, are on the order of one to two magnitudes higher than those at pristine and slightly contaminated sites. These DOC levels also interestingly increase with depth, possibly indicating saltwater

  8. From Ecosystem-Scale to Litter Biochemistry: Controls on Carbon Sequestration in Coastal Wetlands of the Western Gulf of Mexico

    Science.gov (United States)

    Louchouarn, P.; Kaiser, K.; Norwood, M. J.; Sterne, A. M. E.; Armitage, A. R.; HighField, W.; Brody, S.

    2015-12-01

    Landscape-level shifts in plant species distribution and abundance can fundamentally change the structure and services of an ecosystem. Such shifts are occurring within mangrove-marsh ecotones of the U.S., where over the last few decades, relatively mild winters have led to mangrove expansion into areas previously occupied by salt marsh plants. Here we present the synthesis of 3 years of multidisciplinary work to quantify ecosystem shifts at the regional scale, along the entire Texas (USA) coast of the western Gulf of Mexico, and transcribe these shifts into carbon (C) sequestration mass balances. We classified Landsat-5 Thematic Mapper images using artificial neural networks to quantify shifts in areal coverage of black mangrove (Avicennia germinans) and salt marsh (Spartina alterniflora and other grass and forb species) over 20 years across the Texas Gulf coast. Between 1990 and 2010, mangrove area expanded by 74% (+16 km2). Concurrently, salt marsh area experienced a net loss of 24% (-78 km2). Most of that loss was due to conversion to tidal flats or water, likely a result of relative sea level rise, with only 6% attributable to mangrove expansion. Although relative carbon load (per surface area) are statistically larger for mangrove wetlands, total C loads are larger for salt marsh wetlands due to their greater aerial coverage. The entire loss of above ground C (~7.0·109 g), was offset by salt marsh expansion (2.0·109 g) and mangrove expansion (5.6·109 g) over the study period. Concurrently, the net loss in salt marsh coverage led to a loss in below ground C accumulation capacity of 2.0·109 g/yr, whereas the net expansion of mangrove wetlands led to an added below ground C accumulation capacity of 0.4·109 g/yr. Biomarker data show that neutral carbohydrates and lignin contributed 30-70% and 10-40% of total C, respectively, in plant litter and surface sediments. Sharp declines of carbohydrate yields with depth occur parallel to increases in lignin

  9. Mapping the Under Water Habitat Related to their Bathymetry using Worldview-2 (wv-2 Coastal, Yellow, Rededge, Nir-2 Satellite Imagery in Gulf of Mannar to Conserve the Marine Resource

    Directory of Open Access Journals (Sweden)

    R. Uma Maheswari

    2013-02-01

    Full Text Available Gulf of Mannar Marine Biosphere Reserve is the first of its kind in India and also in South East Asia. It extends from Rameswaram to Tuticorin in the South. The Gulf of Mannar encompasses 21 small islands located from 0.5 to 4.0 km2 in area and except a few others are uninhabited. The area is endowed with a combination of ecosystem including mangroves, seagrass, seaweeds and coral reef. The Gulf of Mannar with 3600 species of plants and animals is one of the biologically rich coastal regions in India. Proper planning and effective management of ecosystem can be achieved by collecting data on these ecosystems by the application of Remote Sensing techniques. The combined use of Remote Sensing and Geographical Information System provides a powerful multidisciplinary tool for evaluation of natural resources, both renewable and non-renewable with speed, accuracy and economy. During the present study an attempt is made to explore the advantage of newly added bands [coastal, yellow, red edge and NIR-2] in WV-2 satellite data in mapping the various ocean related parameters such as coral reef, seagrass related to their Bathymetry.

  10. Geology and biology of the "Sticky Grounds," shelf-margin carbonate mounds, and mesophotic ecosystem in the eastern Gulf of Mexico

    Science.gov (United States)

    Locker, Stanley D.; Reed, John K.; Farrington, Stephanie; Harter, Stacey; Hine, Albert C.; Dunn, Shane

    2016-01-01

    Shelf-margin carbonate mounds in water depths of 116–135 m in the eastern Gulf of Mexico along the central west Florida shelf were investigated using swath bathymetry, side-scan sonar, sub-bottom imaging, rock dredging, and submersible dives. These enigmatic structures, known to fisherman as the “Sticky Grounds”, trend along slope, are 5–15 m in relief with base diameters of 5–30 m, and suggest widespread potential for mesophotic reef habitat along the west Florida outer continental shelf. Possible origins are sea-level lowstand coral patch reefs, oyster reefs, or perhaps more recent post-lowstand biohermal development. Rock dredging recovered bioeroded carbonate-rock facies comprised of bored and cemented bioclastics. Rock sample components included calcified worm tubes, pelagic sediment, and oysters normally restricted to brackish nearshore areas. Several reef sites were surveyed at the Sticky Grounds during a cruise in August 2010 with the R/V Seward Johnson using the Johnson-Sea-Link II submersible to ground truth the swath-sonar maps and to quantify and characterize the benthic habitats, benthic macrofauna, fish populations, and coral/sponge cover. This study characterizes for the first time this mesophotic reef ecosystem and associated fish populations, and analyzes the interrelationships of the fish assemblages, benthic habitats and invertebrate biota. These highly eroded rock mounds provide extensive hard-bottom habitat for reef invertebrate species as well as essential fish habitat for reef fish and commercially/recreationally important fish species. The extent and significance of associated living resources with these bottom types is particularly important in light of the 2010 Deepwater Horizon oil spill in the northeastern Gulf and the proximity of the Loop Current. Mapping the distribution of these mesophotic-depth ecosystems is important for quantifying essential fish habitat and describing benthic resources. These activities can improve

  11. Seasonal and interannual changes in zooplankton community in the coastal zone of the North-Eastern Black Sea.

    Science.gov (United States)

    Nikishina, A. B.; Arashkevich, E. G.; Louppova, N. E.; Soloviev, K. A.

    2009-04-01

    The phenological response of zooplankton community is a result of simultaneous effect of several factors: feeding conditions, predation abundance, periods of reproduction of common species and hydrodynamic regime. The Black sea ecosystem is one of the best studied in the world, otherwise there is still some illegibility about ecosystem functioning and especially about environmental factors influence on zooplankton dynamics. For the last twenty years pelagic system of the Black Sea has changed dramatically. The invasion of ctenophore Mnemiopsis leidyi in the middle of eighties caused significant decrease in zooplankton biomass. It also altered plankton structure and shifted periods of mass reproduction of the abundant species and biomass maximums. For instance, before the invasion of Mnemiopsis the maximum of zooplankton biomass was observed in autumn (data by A. Pasternak, 1983), and after that the maximum moved to the spring (data by V.S. Khoroshilov, 1999). The incursion of ctenophore Beroe ovata feeding on Mnemiopsis in the nineties has led to the enhancement of zooplankton community. Although the detailed analysis of seasonal zooplankton dynamics wasn't performed in the recent years. The object of our research was to study seasonal and interannual changes in zooplankton community in the coastal area of the North-Eastern Black Sea. Analysis of interannual, seasonal and spatial changes in zooplankton distribution, abundance and species composition along with age structure of dominant populations were performed based on investigations during 2005-2008 years in the North-Eastern Black Sea. Plankton samples were obtained monthly since June 2005 till December 2008. Plankton was collected at three stations at depths 25m, 50m and 500-1000m along the transect from the Blue Bay to the open sea. Sampling of gelatinous animals was conducted in parallel to the zooplankton sampling. Simultaneously with plankton sampling CTD data were obtained. The feeding conditions were

  12. Eastern Mediterranean sea levels through the last interglacial from a coastal-marine sequence in northern Israel

    Science.gov (United States)

    Sivan, D.; Sisma-Ventura, G.; Greenbaum, N.; Bialik, O. M.; Williams, F. H.; Tamisiea, M. E.; Rohling, E. J.; Frumkin, A.; Avnaim-Katav, S.; Shtienberg, G.; Stein, M.

    2016-08-01

    A last interglacial (Marine Isotope Stage, MIS5e) marine-coastal sequence has been identified along the Galilee coast of Israel, with the type section located at Rosh Hanikra (RH). The microtidal regime and tectonic stability, along with the detailed stratigraphy of the RH shore, make the study region ideally suited for determining relative sea level (RSL) through the MIS5e interval in the eastern Mediterranean. The sequence contains fossilized microtidal subunits at a few meters above the current sea level. Unfortunately, all fossils were found to be altered, so that U-Th datings cannot be considered to represent initial deposition. We contend that U-Th dating of Strombus bubonius shells (recrystallized to calcite) suffices to indicate a lower limit of ∼110 ± 8 ka for the time sea level dropped below the RH sedimentary sequence. The RH-section comprises three main subunits of a previously determined member (the Yasaf Member): (a) a gravelly unit containing the diagnostic gastropod Strombus bubonius Lamarck (Persististrombus latus), which was deposited in the intertidal to super-tidal stormy zone; (b) Vermetidae reef domes indicating a shallow-water depositional environment; and (c) coarse to medium-sized, bioclastic sandstone, probably deposited in the shallow sub-tidal zone. The sequence overlies three abrasion platforms that are cut by tidal channels at elevations of +0.8 m, +2.6 m and +3.4 m, and which are filled with MIS5e sediments. We present a detailed study of the sequence, with emphasis on stratigraphic, sedimentological, and palaeontological characteristics that indicate sea-level changes. Although without precise absolute dating, the stratigraphic sequence of RH through MIS5e allows us to identify a time-series of RSL positions, using the elevations of three stratigraphic subunits. Reconstructed RSL values range from +1.0 m to +7 m (with uncertainly GIA) modelling using multiple ice histories suggests that GIA corrections range between about -1.8 m

  13. Warming, euxinia and sea level rise during the Paleocene-Eocene Thermal Maximum on the Gulf Coastal Plain: implications for ocean oxygenation and nutrient cycling

    Science.gov (United States)

    Sluijs, A.; van Roij, L.; Harrington, G. J.; Schouten, S.; Sessa, J. A.; LeVay, L. J.; Reichart, G.-J.; Slomp, C. P.

    2014-07-01

    The Paleocene-Eocene Thermal Maximum (PETM, ~ 56 Ma) was a ~ 200 kyr episode of global warming, associated with massive injections of 13C-depleted carbon into the ocean-atmosphere system. Although climate change during the PETM is relatively well constrained, effects on marine oxygen concentrations and nutrient cycling remain largely unclear. We identify the PETM in a sediment core from the US margin of the Gulf of Mexico. Biomarker-based paleotemperature proxies (methylation of branched tetraether-cyclization of branched tetraether (MBT-CBT) and TEX86) indicate that continental air and sea surface temperatures warmed from 27-29 to ~ 35 °C, although variations in the relative abundances of terrestrial and marine biomarkers may have influenced these estimates. Vegetation changes, as recorded from pollen assemblages, support this warming. The PETM is bracketed by two unconformities. It overlies Paleocene silt- and mudstones and is rich in angular (thus in situ produced; autochthonous) glauconite grains, which indicate sedimentary condensation. A drop in the relative abundance of terrestrial organic matter and changes in the dinoflagellate cyst assemblages suggest that rising sea level shifted the deposition of terrigenous material landward. This is consistent with previous findings of eustatic sea level rise during the PETM. Regionally, the attribution of the glauconite-rich unit to the PETM implicates the dating of a primate fossil, argued to represent the oldest North American specimen on record. The biomarker isorenieratene within the PETM indicates that euxinic photic zone conditions developed, likely seasonally, along the Gulf Coastal Plain. A global data compilation indicates that O2 concentrations dropped in all ocean basins in response to warming, hydrological change, and carbon cycle feedbacks. This culminated in (seasonal) anoxia along many continental margins, analogous to modern trends. Seafloor deoxygenation and widespread (seasonal) anoxia likely

  14. Concentrations of trace elements in a rare and threatened coastal shark from the Arabian Gulf (smoothtooth blacktip Carcharhinus leiodon).

    Science.gov (United States)

    Moore, Alec B M; Bolam, Thi; Lyons, Brett P; Ellis, Jim R

    2015-11-30

    Kuwait's waters are one of only two locations where the smoothtooth blacktip shark Carcharhinus leiodon is known to occur. Concentrations of 11 trace elements were analysed in five juvenile and two adult specimens of this coastal predator. Concentrations of lead in muscle increased with length, whilst manganese concentration decreased. Arsenic concentrations in muscle were among the highest reported in elasmobranchs, and the concentration in the liver increased significantly in relation to length. In comparison to published literature, concentrations of manganese (liver), lead (muscle) and iron (muscle and liver) were high. Mercury concentrations in the muscle exceeded European Food Safety Authority limits and were among the highest reported in any elasmobranch. Concentrations of selenium, which may inhibit mercury toxicity, were also high. These results and previous studies indicate that potentially hazardous levels of mercury and other contaminants may occur in sharks in this region, adding further stressors to these vulnerable populations.

  15. Distribution of Selected Heavy Metals in Sediment of the River Basin of Coastal Area of Chanthaburi Province, Gulf of Thailand

    Directory of Open Access Journals (Sweden)

    Jakkapan Potipat

    2015-01-01

    Full Text Available The sediment samples from 24 stations in coastal area of Chanthaburi Province were collected during March 2012 to March 2013 and analyzed for heavy metal contents (Pb, Cd, Cr, Fe, Cu and Zn, pH, organic matters and grain sizes. The correlation analyses showed that heavy metal concentrations were affected by the content of organic matter and the size of clay particles. The evaluation of the quality of sediment was carried out using the geoaccumulation index (Igeo and the enrichment factor (EF as well as the comparison with those in the Thailand's sediment quality guideline (SQG values. The results of the geoaccumulation index and the enrichment factor values of the heavy metals content in the sediments revealed that the study area was unpolluted and not enriched, respectively. The relationship between the heavy metals concentration and the organic matter, and the clay particle was proposed by using the multiple regression equations.

  16. Discrimination of inland and coastal dunes in Eastern Saudi Arabia desert system: An approach from particle size and textural parameter variations

    Science.gov (United States)

    Koeshidayatullah, Ardiansyah; Chan, Septriandi Asmaidi; Al-Ghamdi, Majed; Akif, Tariq; Al-Ramadan, Khalid

    2016-05-01

    Different particle size parameters have been investigated in this study in order to distinguish the characteristics of different dune morphologies in the Eastern Saudi Arabia. Sand samples were collected from various environments including: the stoss, lee, crest and interdune sides of the inland dunes and foreshore; berm; backshore and backdune of the coastal dunes. Statistical parameters reveal that the majority of inland dune samples are dominated by well sorted fine sand whereas coastal dune samples are mainly dominated by very coarse to medium sand, ranging from well sorted to moderately sorted with a low percentage of silt and clay. The presence of relatively coarser grains in the coastal dunes might be explained by continuous wind deflation along the coast together with wave and tidal activities that concentrate coarser grains. Cross-plots from four statistical parameters and supported by the ANOVA test clearly distinguish the particle variations between these dunes. The log-probability analysis suggest that the main transport mechanism in inland and coastal dunes is dominated by the saltation population, comprising up to 80 percent of the distribution. However, the coastal dunes suspension population is mostly belonging to coarser grained material, whereas the inland dunes population is finer. In comparison with particle size characteristics of dunes in the region, the current study shows a close relationship to mean particle size in Iraq, but is relatively finer compared to the Kuwait dunes. This similarity and difference in particle size variation is mostly controlled by the proximity to the coast and also the wind energy and variation in the wind direction.

  17. Mercury Speciation at a Coastal Site in the Northern Gulf of Mexico: Results from the Grand Bay Intensive Studies in Summer 2010 and Spring 2011

    Directory of Open Access Journals (Sweden)

    Xinrong Ren

    2014-04-01

    , which is located in a coastal environment of the Gulf of Mexico, experienced impacts from mercury sources that are both local and regional in nature.

  18. [Environmental heterogeneity and its relationship with diversity and abundance of the fish community in a coastal system of Gulf of Mexico].

    Science.gov (United States)

    Aguirre-León, Arturo; Pérez-Ponce, Hilda Elín; Díaz-Ruiz, Silvia

    2014-03-01

    The coastal lagoons of Veracruz, Gulf of Mexico, include a great variety of biological resources. These resources, especially fish communities, have been barely described and that require more ecological studies. With this aim, this investigation analyzed the spatial and temporal variation of diversity, abundance and assemblages of the fish community and its relationship with physical-chemical parameters of the Chica-Grande coastal system. For this, eight defined sites were monthly sampled for water characteristics and fish community composition (10min hauls of 1 500m2 a shrimp trawl net), between September 2005 and November 2006. The spatial-temporal variation of physical-chemical parameters, allowed the definition of two contrasting environments according to salinity, temperature, transparency, dissolved oxygen and depth gradients. A total of 1 947 fishes were collected for a total weight of 57.88kg. From these, 22 species, 20 genera and 14 families were identified; and four species were new records for the system. As it was detected for the physical-chemical conditions, the diversity of the fish community also showed a spatial gradient, with high values (H'=2.37, D=3.35, J'=0.82) in the brackish habitat, and low ones in freshwater environments. Fish abundance did not show such a marked gradient response, however, it was higher in the freshwater habitat. The highest diversity (H'=2.05) and species richness (D=2.99) was recorded during the North winds ("nortes") months (November-February), while density and biomass were higher (0.034 ind./m2, 1.42g/m2) during the rainy months (July-October). The Importance Value Index (IVI) defined six dominant species accounting for 77.8% of the fish abundance and 87.9% of total catch by weight. The Canonical Correspondence Analysis (CCA) showed that the fish-habitat relationship was explained by 68% of total variance for the two first axes, where salinity, transparency and temperature changes were the most important

  19. Satellite Assessment of Bio-Optical Properties of Northern Gulf of Mexico Coastal Waters Following Hurricanes Katrina and Rita

    Science.gov (United States)

    Lohrenz, Steven E.; Cai, Wei-Jun; Chen, Xiaogang; Tuel, Merritt

    2008-01-01

    The impacts of major tropical storms events on coastal waters include sediment resuspension, intense water column mixing, and increased delivery of terrestrial materials into coastal waters. We examined satellite imagery acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS) ocean color sensor aboard the Aqua spacecraft following two major hurricane events: Hurricane Katrina, which made landfall on 29 August 2005, and Hurricane Rita, which made landfall on 24 September. MODIS Aqua true color imagery revealed high turbidity levels in shelf waters immediately following the storms indicative of intense resuspension. However, imagery following the landfall of Katrina showed relatively rapid return of shelf water mass properties to pre-storm conditions. Indeed, MODIS Aqua-derived estimates of diffuse attenuation at 490 nm (K_490) and chlorophyll (chlor_a) from mid-August prior to the landfall of Hurricane Katrina were comparable to those observed in mid-September following the storm. Regions of elevated K_490 and chlor_a were evident in offshore waters and appeared to be associated with cyclonic circulation (cold-core eddies) identified on the basis of sea surface height anomaly (SSHA). Imagery acquired shortly after Hurricane Rita made landfall showed increased water column turbidity extending over a large area of the shelf off Louisiana and Texas, consistent with intense resuspension and sediment disturbance. An interannual comparison of satellite-derived estimates of K_490 for late September and early October revealed relatively lower levels in 2005, compared to the mean for the prior three years, in the vicinity of the Mississippi River birdfoot delta. In contrast, levels above the previous three year mean were observed off Texas and Louisiana 7-10 d after the passage of Rita. The lower values of K_490 near the delta could be attributed to relatively low river discharge during the preceding months of the 2005 season. The elevated levels off Texas and

  20. Satellite Assessment of Bio-Optical Properties of Northern Gulf of Mexico Coastal Waters Following Hurricanes Katrina and Rita

    Directory of Open Access Journals (Sweden)

    Merritt Tuel

    2008-07-01

    Full Text Available The impacts of major tropical storms events on coastal waters include sediment resuspension, intense water column mixing, and increased delivery of terrestrial materials into coastal waters. We examined satellite imagery acquired by the Moderate Resolution Imaging Spectroradiometer (MODIS ocean color sensor aboard the Aqua spacecraft following two major hurricane events: Hurricane Katrina, which made landfall on 29 August 2005, and Hurricane Rita, which made landfall on 24 September. MODIS Aqua true color imagery revealed high turbidity levels in shelf waters immediately following the storms indicative of intense resuspension. However, imagery following the landfall of Katrina showed relatively rapid return of shelf water mass properties to pre-storm conditions. Indeed, MODIS Aqua-derived estimates of diffuse attenuation at 490 nm (K_490 and chlorophyll (chlor_a from mid-August prior to the landfall of Hurricane Katrina were comparable to those observed in mid-September following the storm. Regions of elevated K_490 and chlor_a were evident in offshore waters and appeared to be associated with cyclonic circulation (cold-core eddies identified on the basis of sea surface height anomaly (SSHA. Imagery acquired shortly after Hurricane Rita made landfall showed increased water column turbidity extending over a large area of the shelf off Louisiana and Texas, consistent with intense resuspension and sediment disturbance. An interannual comparison of satellite-derived estimates of K_490 for late September and early October revealed relatively lower levels in 2005, compared to the mean for the prior three years, in the vicinity of the Mississippi River birdfoot delta. In contrast, levels above the previous three year mean were observed off Texas and Louisiana 7-10 d after the passage of Rita. The lower values of K_490 near the delta could be attributed to relatively low river discharge during the preceding months of the 2005 season. The elevated levels

  1. Partial pressure (or fugacity) of carbon dioxide, dissolved inorganic carbon, pH, alkalinity, temperature, salinity and other variables collected from Surface underway observations using Carbon dioxide (CO2) gas analyzer, Shower head chamber equilibrator for autonomous carbon dioxide (CO2) measurement and other instruments from WEATHERBIRD II in the Coastal Waters of Florida and Gulf of Mexico from 2008-08-11 to 2011-06-30 (NCEI Accession 0144622)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0144622 includes Surface underway data collected from WEATHERBIRD II in the Coastal Waters of Florida and Gulf of Mexico from 2008-08-11 to...

  2. Bacterial community shift in the coastal Gulf of Mexico salt-marsh sediment microcosm in vitro following exposure to the Mississippi Canyon Block 252 oil (MC252)

    KAUST Repository

    Koo, Hyunmin

    2014-07-10

    In this study, we examined the responses by the indigenous bacterial communities in salt-marsh sediment microcosms in vitro following treatment with Mississippi Canyon Block 252 oil (MC252). Microcosms were constructed of sediment and seawater collected from Bayou La Batre located in coastal Alabama on the Gulf of Mexico. We used an amplicon pyrosequencing approach on microcosm sediment metagenome targeting the V3–V5 region of the 16S rRNA gene. Overall, we identified a shift in the bacterial community in three distinct groups. The first group was the early responders (orders Pseudomonadales and Oceanospirillales within class Gammaproteobacteria), which increased their relative abundance within 2 weeks and were maintained 3 weeks after oil treatment. The second group was identified as early, but transient responders (order Rhodobacterales within class Alphaproteobacteria; class Epsilonproteobacteria), which increased their population by 2 weeks, but returned to the basal level 3 weeks after oil treatment. The third group was the late responders (order Clostridiales within phylum Firmicutes; order Methylococcales within class Gammaproteobacteria; and phylum Tenericutes), which only increased 3 weeks after oil treatment. Furthermore, we identified oil-sensitive bacterial taxa (order Chromatiales within class Gammaproteobacteria; order Syntrophobacterales within class Deltaproteobacteria), which decreased in their population after 2 weeks of oil treatment. Detection of alkane (alkB), catechol (C2,3DO) and biphenyl (bph) biodegradation genes by PCR, particularly in oil-treated sediment metacommunity DNA, delineates proliferation of the hydrocarbon degrading bacterial community. Overall, the indigenous bacterial communities in our salt-marsh sediment in vitro microcosm study responded rapidly and shifted towards members of the taxonomic groups that are capable of surviving in an MC252 oil-contaminated environment.

  3. A numerical analysis of shipboard and coastal zone color scanner time series of new production within Gulf Stream cyclonic eddies in the South Atlantic Bight

    Science.gov (United States)

    Pribble, J. Raymond; Walsh, John J.; Dieterle, Dwight A.; Mueller-Karger, Frank E.

    1994-01-01

    Eddy-induced upwelling occurs along the western edge of the Gulf Stream between Cape Canaveral, Florida, and Cape Hatteras, North Carolina, in the South Atlantic Bight (SAB). Coastal zone color scanner images of 1-km resolution spanning the period April 13-21, 1979, were processed to examine these eddy features in relation to concurrent shipboard and current/temperature measurements at moored arrays. A quasi-one-dimensional (z), time dependent biological model, using only nitrate as a nutrient source, has been combined with a three-dimensional physical model in an attempt to replicate the observed phytoplankton field at the northward edge of an eddy. The model is applicable only to the SAB south of the Charleston Bump, at approximately 31.5 deg N, since no feature analogous to the bump exists in the model bathymetry. The modeled chlorophyll, nitrate, and primary production fields of the euphotic zone are very similar to those obtained from the satellite and shipboard data at the leading edges of the observed eddies south of the Charleston Bump. The horizontal and vertical simulated fluxes of nitrate and chlorophyll show that only approximately 10% of the upwelled nitrate is utilized by the phytoplankton of the modeled grid box on the northern edge of the cyclone, while approximately 75% is lost horizontally, with the remainder still in the euphotic zone after the 10-day period of the model. Loss of chlorophyll due to sinking is very small in this strong upwelling region of the cyclone. The model is relatively insensitive to variations in the sinking parameterization and the external nitrate and chlorophyll fields but is very sensitive to a reduction of the maximum potential growth rate to half that measured. Given the success of this model in simulating the new production of the selcted upwelling region, other upwelling regions for which measurements or successful models of physical and biological quantities and rates exist could be modeled similarly.

  4. Temporal fluctuations of the Sea Surface Temperature and Chlorophyll-a along of coral reef systems located on the Western coastal zone of the Gulf of Mexico

    Science.gov (United States)

    de Jesús Salas Pérez, José; Ocaña Valencia, Angel; González Gandara, Carlos

    2014-05-01

    On the coastal zone of the western Gulf of Mexico (GM), there are a variety of coral reef systems which are influenced by river discharge and macro-scale circulation of the GM. The goal of this study is determine if the main fluctuations of the chlorophyll-a and sea surface temperature values (measured from monthly satellite images of sensors Aqua Modis and NOAA-AVHRR in the period of 2008-2011) in coral reef systems, are determined by river discharges or macro-scale circulation of the basin. Moreover determine if the temporal fluctuations of those parameters are correlated between them and thus asses the relationship between them. The most norther coral reef system (Lobos) is classified as mesotrophic-eutrophic. The middle coral reef system (Tuxpan) is ranked as oligotrophic-mesotrophic. Toward the southern region of the western littoral of the GM the coral reefs systems (PNSAV and Coatzacoalcos) are classified as eutrophic. Regarding to Sea Surface Temperature (SST) fluctuations, all coral reef systems showed an almost similar behavior, winter is the season with cool waters (19-23°C). Then in spring, the temperature values increases to about 25°C. Summer season have warm waters (29-30°C). Slightly different, fall decrease their water temperatures to 28°C. The northern coral reef systems (Lobos-Tuxpan) are colder than that the coral reef systems of the southern region (PNSAV-Coatzacoalcos). Those fluctuations, in chlorophyll-a and SST are induced by cyclonic and anticyclonic gyres generated in the Loop current, which impact in the northern region, while the southern region is influenced by river discharge and the presence of a cyclonic gyre of the Campeche bay. But northern and southern coral reef systems are mainly affected by waters of the northern GM advected by winds blowing from the north, mainly in winter.

  5. Possible role of hydroisostasy in peculiarities of lateglacial - postglacial sedimentation of the eastern part of the Gulf of Finland and Lake Ladoga

    Science.gov (United States)

    Amantov, Aleksey; Ryabchuk, Daria; Fjeldskaar, Willy; Zhamoida, Vladimir; Amantova, Marina

    2013-04-01

    Baltic - Lake Ladoga - White Sea structural-denudational lowland extends along the margin of the Baltic (Fennoscandian) Shield. Its deepest parts in the bedrock and modern landscape usually coincide with zones of cropping out of the post-late Vendian platform non-metamorphosed cover or outcrops of Riphean formations that overly metamorphic basement. Landscape of this area was variably modified by different processes, in particular by strong Pleistocene glacial and fluvioglacial erosion, strongly controlled by lithological and structural factors. The bedrock is variably dissected by erosion, especially on terrigenous sediments, where deep tunnel valleys are common. Simply, it is normally covered by Late Weichselian till of variable thickness overlain by glaciolacustrine varved clay sequence of the Baltic Ice Lak. The study (partly suppoted by RFBR grant 12-05-01121-A) focus on prominent feature of distinct erosional truncation prior to Holocene lacustrine and marine sedimentation, traced as deep as 50 - 60 m b.s.l. in the wider eastern part of the Gulf of Finland. We speculate that deep sediment erosion was caused by the increasing role of variable hydroisostatic uplift of the bottom in response to well known water-level lowering, starting from the Yoldia Sea lowstand ~ 11 560 - 11 600 cal. BP. The bottom locally could be additionally uplifted 8-10 m solely due to this factor. We also discuss possible input of remaining forebulge migration in deep bottom erosion. Relevant role of global climate changes, possible permafrost degradation, hydrogeological recharge of aquifers and water balance of large lake systems can not be neglected. Stress-specific unstable anisotropic varved clays with internal water-bearing silt - sand layers traditionally responded on rapid changes by zonal debris flows and slope deformations.

  6. Coastal marine basins as records of continental palaeoenvironments (Gulf of Guinea and Iullemmeden cretaceous and tertiary basins)

    Science.gov (United States)

    Rat, P.; Lang, J.; Alzouma, K.; Dikouma, M.; Johnson, A.; Laurin, B.; Mathey, B.; Pascal, A.

    Deposits in nearshore marine basins provide data about the adjacent emerged lands. Examples are taken from the Togo coastal basin, on an ocean margin, and the Iullemmeden intracratonic basin (Niger). A continental landscape is fossilized by the onlapping layers of the transgressions: an eroded crystalline basement (Togo) or a broad and complex alluvial plain (Iullemmeden). Clastics, trapped in the marine deposits, provide information on the source area. Two types of information can be obtained from the sands: the nature of the parent rocks, and the environment at the time of genesis, storage and transportation (tectonic and climatic stability or change). The significance of clays is more complex; they can be formed or modified in the marine environment. However their elastic or chemical components originate from biochemical weathering and provide information on climate, morphology, vegetation cover and drainage of the emerged lands. In the Iullemmeden basin, the important change between Maastrichtian and Paleocene probably reflects a change to a drier climate in accordance with a slight shift of the equator to the south. The properties of marine waters are dependent on climate and morphology of the emergent lands which determines runoff. These properties may be inferred from the analysis of the clastic/carbonate conflict and indicators of salinity (mangrove). In conclusion, the Togo and Iullemmeden basins were located downstream of tectonically quiecent, large continental areas of gentle relief. Transgressions were migrations of a broad littoral system upon very flat continental surfaces caused by erosion or river-dominated deposition.

  7. Giardiasis in pinnipeds from eastern Canada.

    Science.gov (United States)

    Measures, L N; Olson, M

    1999-10-01

    Cysts of Giardia sp. were detected in feces from the rectum of 20 of 74 pinnipeds examined from the eastern coast of Canada in 1997 and 1998 using a monoclonal antibody technique. Infected pinnipeds included 15 adult harp seals (Phoca groenlandica), four adult grey seals (Halichoerus grypus), and one juvenile harbor seal (Phoca vitulina). Cysts were not detected in 15 seal pups St. Lawrence. The overall prevalence of Giardia sp. in grey and harbor seals, excluding pups, from the Gulf and St. Lawrence estuary was 23%. Feces from 11 beluga (Delphinapterus leucas) and one northern bottle-nosed whale (Hyperoodon ampullatus) stranded in the St. Lawrence estuary were negative for Giardia sp. cysts. The significance of Giardia sp. in marine mammals, shown here for the first time in eastern coastal Canada, is unknown.

  8. Use of a time-domain electromagnetic method with geochemical tracers to explore the salinity anomalies in a small coastal aquifer in north-eastern Tunisia

    Science.gov (United States)

    Chekirbane, Anis; Tsujimura, Maki; Kawachi, Atsushi; Lachaal, Fethi; Isoda, Hiroko; Tarhouni, Jamila

    2014-12-01

    The study area is a small coastal plain in north-eastern Tunisia. It is drained by an ephemeral stream network and is subject to several pollutant discharges such as oilfield brine coming from a neighboring oil company and wastewater from Somâa city, located in the upstream of the plain. Furthermore, a hydraulic head near the coastal part of the aquifer is below sea level, suggesting that seawater intrusion may occur. A time-domain electromagnetic (TDEM) survey, based on 28 soundings, was conducted in Wadi Al Ayn and Daroufa plains to delineate the saline groundwater. Based on longitudinal and transversal resistivity two-dimensional pseudosections calibrated with boring data, the extent of saline water was identified. Geochemical tracers were combined with the resistivity dataset to differentiate the origin of groundwater salinization. In the upstream part of the plain, the infiltration of oilfield brine through the sandy bed of Wadi Al Ayn seems to have a considerable effect on groundwater salinization. However, in the coastal part of the aquifer, groundwater salinization is due to seawater intrusion and the saltwater is reaching an inland extent around 1.3 km from the shoreline. The contribution ratios of saline water bodies derived from the inverted chloride data vary for the oilfield brine from 1 to 13 % and for the seawater from 2 to 21 %.

  9. SOME BIOLOGICAL ASPECTS OF SCALLOPED HAMMERHEAD SHARKS (Sphyrna lewini Griffith & Smith, 1834 CAUGHT FROM COASTAL FISHERIES IN THE EASTERN INDIAN OCEAN

    Directory of Open Access Journals (Sweden)

    Umi Chodrijah

    2015-12-01

    Full Text Available Indonesia has the largest chondrichthyan fishery in the world, with a reported of 105,000 and 118,000 tonnes landed in 2002 and 2003 respectively. Scalloped hammerhead shark was either targeted or by-catch from this fishery, mostly for its fins. Despite of the growing concern around the world, the availability of biological data of this species, especially in the Eastern Indian Ocean is still lacking. The objectives of this paper are to present some biological information (size composition and sex ratio of the scalloped hammerhead, from coastal fisheries in Eastern Indian Ocean. The data used for the analysis comprised of two components, i.e. survey data in 2010 (February, March, June, August, October and December and data from daily monitoring shark landing in 2013 (January to December. Substantially lower mean size, more immature sharks and more frequent of female caught over years showed that scalloped hammerhead shark in the Eastern Indian Ocean are facing intensive fishing pressure which could lead to overfishing. This could harm the sustainability of scalloped hammerhead shark resource in the long run. The relationship between clasper length and total length was positively correlated where every 5 cmTL increment on clasper length adding 51 cmTL on total length.

  10. Seasonal and interannual variability of sedimentation and organic matter distribution in the Buor Khaya Gulf – the primary recipient of input from Lena River and coastal erosion in the SE Laptev Sea

    Directory of Open Access Journals (Sweden)

    A. N. Charkin

    2011-02-01

    Full Text Available Climate warming is amplified in the land-sea system of the East Siberian Arctic, which also holds large pools of vulnerable carbon in permafrost. This coastal area is strongly influenced by sediment and carbon transport from both its large rivers and extensive erosion of Pleistocene permafrost along its coastline. This study is investigating the coastal fate of the sediment and organic carbon delivered to the Buor-Khaya Gulf, which is the first recipient of the 16 overwhelming fluvial discharge from the Lena River and is additionally receiving large input from extensive erosion of the coastal ice-complex (permafrost a.k.a. Yedoma; loess soil with high organic carbon content. Both water column suspended particulate matter (SPM and surface sediments were sampled at about 250 oceanographic stations in the Gulf in this multiyear effort, including one winter campaign, and analyzed for the distribution and sorting of sediment size, organic carbon content, and stable carbon isotope signals. The composition of the surface sediment suggests an overwhelmingly terrestrial contribution from both river and coastal erosion.

    Based on data collected during several years in the period 2000–2008, two different sedimentation regimes were revealed for the Buor-Khaya Gulf, the relative importance of each at a given time depend on hydrometeorological conditions, the Lena River water discharge and sea-ice regime: Type 1 erosion-accumulation and Type 2 accumulation.

    The Type 1 erosion-accumulation sedimentation regime is typical (2000–2006 for the ice-free period of the year (here considered in detail for August 2005. Under such conditions terrigenous sources of suspended particulate matter (SPM and particulate organic carbon (POC stem predominantly from river discharge, thermal erosion of coastal ice-complex and remobilized bottom sediments. The Type 2 accumulation sedimentation regime develops under ice

  11. Investigating the Relationship of Late Pleistocene Terrace Formation and Channel Dynamics within the Texas Gulf Coastal Plain

    Science.gov (United States)

    Ellis, T.; Hassenruck-Gudipati, H. J.; Mohrig, D. C.; Goudge, T. A.

    2016-12-01

    Terrace formation along coastal rivers is often assumed to be a direct result of punctuated sea-level fall. However, it has been experimentally shown that terraces commonly form under conditions of constant base level fall. In addition, it has been demonstrated that migrating channels in a bedrock system with steady state rock uplift can produce similar looking terraces. The lower Trinity River, in East Texas, is an ideal location to study allogenic (punctuated external forcing) versus autogenic terrace-building mechanisms using lidar measurements and OSL depositional age constraints (Gavin, 2005). To understand paleochannel influence on terrace construction, we measured channel characteristics for 27 preserved segments of paleochannels that are late Pleistocene in age and associated with 27 of 34 measured terraces along about 90 km of the modern river. There is no clear clustering of terrace elevation that might be tied to distinct sea level change events. Rather, the range of mean terrace elevations is indicative of a more constant system transformation. Based on lidar measurements, all paleochannels are larger than the modern channel, suggesting a wetter climate or larger watershed. Channel width measurements are used to quantify these changes in paleoflow discharge. Paleochannel width, radius of curvature and terrace slope measurements are used to characterize the movement of an incising channel. Based upon OSL terrace dates (Gavin, 2005), known global climate variations can be compared to discharge estimates and investigated as a predictor of terrace formation. If terrace formation occurred during distinct intervals of sea level fall, terraces with similar calculated paleoflow discharges are expected to plot along specific downstream elevation profiles. Assuming avulsion-driven terrace formation occurs at locations of higher channel sinuosity, the sinuosity of paleochannels on terraces is compared to the sinuosity of the modern river. Higher paleo

  12. Anthropogenic nitrogen in a subtropical coastal lagoon (SE Gulf of California): sources and ecological consequences using isotopes stables

    Science.gov (United States)

    Soto-Jimenez, M.; Paez-Osuna, F.

    2007-05-01

    Chemical and isotopic compositions of N were studied in anthropogenic effluents received by Altata-Ensenada- Pabellón lagoon (AEP), a typical coastal ecosystem along the SE GC. Human activities mobilize from 33,000 to 55,000 tons of N per year to the AEP, which the agriculture (70%), livestock (10%), and atmospheric deposition (10%) are the largest N sources. Other N sources including sewage, shrimp farming, poultry, and livestock effluents constituted less than 10% of N inputs. The N is distributed as inorganic N that accounts for an input of 72% (NO3- 65% and NH4+ 7%) and organic N for 28% (>90% of the organic N occurring as DON). The N isotopic composition in the different effluents vary 6.1-16.1‰ for 15N-NH4+ and 2.1-15.9‰ for 15N-NO3. The 15N-NO3- values in agriculture effluents are related to fertilizer, while the enriched values of 15N-NH4+ in sewage and animal effluents and 15N-NO3- in groundwater result of the high ammonification and denitrification during the transport to the lagoon. Overall the C/N ratios (5.3-21.1) and isotopic signatures (13C -30.6 to -21.4‰ and 15N 6.1-12.5‰) in the POM for the diverse effluents had measurable differences and consistent with their origins. The 15N-DIN values measured at the selected stations recording inputs into AEP lagoon waters oscillated from 4.4 to 6.5‰ for 15N- NO3-, 12.9 to 20.9‰ 15N-NH4+, and from 4.4 to 10‰ 15N-POM. Overall the 15N values predicted by mass balances are in the range of the measured isotopic composition. The N requirement in Pacific Mexican lagoons is estimated to be 155 to 400 kg N ha-1 y-1, however, the current level is 1480 kg N ha-1 y-1, with anthropogenic N inputs (1200 kg N ha-1 y-1) of 80%. This excess of primary productivity is evidenced by the phytoplankton and macroalgae blooms that occur year-round, mainly in the areas close to the nutrient discharges from AEP lagoon.

  13. A new species of symbiotic palaemonid shrimp of the genus Pseudocoutierea Holthuis, 1951 (Decapoda: Caridea: Palaemonidae) from the eastern Gulf of Mexico, with an updated key for the identification of species of the genus.

    Science.gov (United States)

    Ramos-Tafur, Gabriel E; Lemaitre, Rafael

    2016-10-06

    A new species of symbiotic palaemonid shrimp of the genus Pseudocoutierea Holthuis, 1951, is described based on a specimen collected in the eastern Gulf of Mexico, off the southwest coast of Florida. Pseudocoutierea stephanieae sp. nov., is the seventh known in this genus, and morphologically most similar to P. antillensis Chace, 1972, and P. conchae Criales, 1981, from the western Atlantic, and P. elegans Holthuis, 1952, from the eastern Pacific, all sharing an expanded rostral base or eaves that terminate supra-distally in an acute tooth. This new species can be separated by: the presence of an epigastric knob or tubercle on the anterior mid-dorsal third of the carapace, which is absent in all other congeneric species; the shape of the pterygostomial sinus, which is shallow in this new species, whereas it is deep and well defined in all other congeneric species. An updated dichotomous key to species of Pseudocoutierea is presented.

  14. 2004 Pre-Hurricane Ivan Eastern Gulf Coast United States Army Corps of Engineers (USACE) Lidar-Derived Dune Crest, Toe and Shoreline

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Storm-Induced Coastal Change Hazards component of the National Assessment of Coastal Change Hazards project focuses on understanding the magnitude and...

  15. Eastern Australian Coastal Behaviour in Response to Extreme Storm Climate Between 1600-1900 AD, Determined from a Coupled Climate Reconstruction and Coastal Morphodynamic Approach

    Science.gov (United States)

    Goodwin, I. D.; Browning, S. A.; Mortlock, T.

    2014-12-01

    A sustained morphodynamic reorganisation of the east Australian coast occurred over a large latitudinal gradient from subtropical Queensland (S 25°) to mid-latitude Bass Strait (S 40°) between ~1600 to 1900 CE. These changes indicate that a large-scale shift in the modal climate occurred together with changes in extreme storm frequency or clustering of East Coast Cyclones (ECC), when compared to the past century. ECC are complex subtropical weather systems that form off the east coast of Australia and/or travel parallel to the coast of Australia from south-east Queensland to Victoria. We investigate coastal evolution and the associated climate drivers using a novel combination of methods, including: LIDAR DEM and field mapping of coastal geology; a decadal-scale climate reconstruction of sea-level pressure, marine windfields, and paleo-storm synoptic type and frequency, using a paleoclimate data assimilation approach; together with wave transformation and coastal planform modelling for paleo-wave directions, and historical bathymetry. We present the morphodynamic response to changes in directional wave power, by linking the paleo-windfield reconstruction to wave transformation models. The combined methodology has illuminated the 'ultimate' storm impacts not seen in the past century, and defines the multi-decadal coastal system response and recovery to extreme storm sequences. Increased embaymentisation and anticlockwise rotation of embayed and barrier coast planform geometry; shifts in barrier-estuary-inlet configuration; and a ubiquitous foredune transgression, are shown to have occurred between ~1600 to 1800 CE. This was in response to a poleward shift in the subtropics and frequency of tradewind-driven wave climate, and tropical-origin storms. From 1800 to 1900 CE, an equatorward shift in the subtropics, and clustering of extratropical-origin storms drove an increase in the shoreface-littoral sediment budget and a clockwise coastline progradation. This

  16. Population genetic structure of the round stingray Urobatis halleri (Elasmobranchii: Rajiformes) in southern California and the Gulf of California.

    Science.gov (United States)

    Plank, S M; Lowe, C G; Feldheim, K A; Wilson, R R; Brusslan, J A

    2010-08-01

    The round stingray, Urobatis halleri, is a viviparous elasmobranch that inhabits inshore, benthic habitats ranging from the western U.S.A. to Panama. The population genetic structure of this species was inferred with seven polymorphic microsatellite loci in samples collected at three sites in coastal southern California, one near Santa Catalina Island, California and one in the eastern Gulf of California. Urobatis halleri is relatively common, but little is known of its movement patterns or population structure. Small F(ST) values (-0.0017 to 0.0005) suggested little structure among coastal populations of southern and Baja California. The population sampled at Santa Catalina Island, which is separated by a deep-water channel from the coastal sites, however, was significantly divergent (large F(ST), 0.0251) from the other populations, suggesting low connectivity with coastal populations. The Santa Catalina Island population also had the lowest allele richness and lowest average heterozygosity, suggesting recent population bottlenecks in size.

  17. Vertical datum conversion process for the inland and coastal gage network located in the New England, Mid-Atlantic, and South Atlantic-Gulf hydrologic regions

    Science.gov (United States)

    Rydlund, Jr., Paul H.; Noll, Michael L.

    2017-03-07

    Datum conversions from the National Geodetic Vertical Datum of 1929 to the North American Vertical Datum of 1988 among inland and coastal gages throughout the hydrologic regions of New England, the Mid-Atlantic, and the South Atlantic-Gulf have implications among river and storm surge forecasting, general commerce, and water-control operations. The process of data conversions may involve the application of a recovered National Geodetic Vertical Datum of 1929–North American Vertical Datum of 1988 offset, a simplistic datum transformation using VDatum or VERTCON software, or a survey, depending on a gaging network datum evaluation, anticipated uncertainties for data use among the cooperative water community, and methods used to derive the conversion. Datum transformations from National Geodetic Vertical Datum of 1929 to North American Vertical Datum of 1988 using VERTCON purport errors of ± 0.13 foot at the 95 percent confidence level among modeled points, claiming more consistency along the east coast. Survey methods involving differential and trigonometric leveling, along with observations using Global Navigation Satellite System technology, afford a variety of approaches to establish or perpetuate a datum during a survey. Uncertainties among leveling approaches are generally control or construction projects and ±0.16 foot for Federal Emergency Management Agency field surveys and checkpoint surveys used for mapping. River level forecasts generally are defined as ± 0.10 foot among the National Oceanic and Atmospheric Administration–National Weather Service. Collaboration and communication among the cooperative water community is necessary during a datum conversion or datum change. Datum notification time-change requirements set by the National Oceanic and Atmospheric Administration–National Weather Service vary from 30 to 120 days, depending on datum conversion or datum-change case scenarios. Notification times associated with these case scenarios may

  18. Seasonal and interannual variability of sedimentation and organic matter distribution in the Buor-Khaya Gulf: the primary recipient of input from Lena River and coastal erosion in the southeast Laptev Sea

    Directory of Open Access Journals (Sweden)

    A. N. Charkin

    2011-09-01

    Full Text Available Climate warming is amplified in the land-sea system of the East Siberian Arctic, which also holds large pools of vulnerable carbon in permafrost. This coastal area is strongly influenced by sediment and carbon transport from both its large rivers and extensive erosion of Pleistocene permafrost along its coastline. This study is investigating the coastal fate of the sediment and organic carbon delivered to the Buor-Khaya Gulf, which is the first recipient of the overwhelming fluvial discharge from the Lena River and is additionally receiving large input from extensive erosion of the coastal ice-complex (permafrost a.k.a. Yedoma; loess soil with high organic carbon content. Both water column suspended particulate matter (SPM and surface sediments were sampled at about 250 oceanographic stations in the Gulf in this multi-year effort, including one winter campaign, and analyzed for the distribution and sorting of sediment size, organic carbon content, and stable carbon isotope signals. The composition of the surface sediment suggests an overwhelmingly terrestrial contribution from both river and coastal erosion. The objective of this paper is to improve our understanding of the seasonal (i.e., winter vs summer and interannual variability of these coastal sedimentation processes and the dynamics of organic carbon (OC distribution in both the water column SPM and the surface sediments of the Buor-Khaya Gulf.

    Based on data collected during several years in the period 2000–2008, two different sedimentation regimes were revealed for the Buor-Khaya Gulf, the relative importance of each at a given time depend on hydrometeorological conditions, the Lena River water discharge and sea-ice regime: Type 1 erosion-accumulation and Type 2 accumulation.

    The Type 1 erosion-accumulation sedimentation regime is typical (2000–2006 for the ice-free period of the year (here considered in detail for August 2005. Under such conditions terrigenous

  19. Geochemistry and particle size of surface sediments of Exmouth Gulf, Northwest Shelf, Australia

    Science.gov (United States)

    Brunskill, G. J.; Orpin, A. R.; Zagorskis, I.; Woolfe, K. J.; Ellison, J.

    2001-01-01

    Exmouth Gulf is a shallow (mean depth 11.9 m, 2600 km 2 area) inverse estuarine embayment on the northwest shelf of Australia, with a catchment area of 6400 km 2 with low human and livestock populations in an arid climate. The Gulf is an extreme example of a tide and wave dominated estuary, with very small river inputs. Freshwater supply from the land is very small, and terrestrial run-off nutrient supply is estimated to be 0.8 mmol TN and 0.4 mmol TP per square metre Gulf area per year (TN=total dissolved and particulate nitrogen, TP=total dissolved and particulate phosphorus). Holocene deposits in the mangrove margins are less than 1 m thick, and are relict and partly aeolian in origin. Surficial sediments are largely quartz and calcite sand, and fine-grained recent sediments are probably removed by energetic Indian Ocean tide and wave mixing and circulation. Geochemical variations in sediment composition across the Gulf are small, and appear to be little affected by redox cycles. Marine organic matter is efficiently decomposed, leaving behind excess phosphorus associated with carbonate and iron-rich sediments. The thin ribbon of stunted mangroves along the eastern margin of the Gulf has little influence on the composition of sedimentary organic matter in the Gulf, and the mangrove sediments are not a trap for trace elements as has been found in other parts of the tropical world. Ba, Li, Pb, and Cu vary in direct proportion to the abundance of the bulk sediment aluminosilicate fraction, boron is enriched by evaporation in the supratidal saltflat regions, and cadmium has large variations perhaps related to the carbonate fraction of the sediments. There is little evidence for coastal trapping of sediment and oceanic elements in Exmouth Gulf, and some regions of the intertidal mangrove and saltflat zones are being eroded into the Gulf and adjacent shelf.

  20. A recent perspective of the Circulation in the Gulf of Mexico

    Science.gov (United States)

    Candela, J.; Ochoa-de-La-Torre, J. L.; Sheinbaum, J.; Perez-Brunius, P.; Pallas-Sanz, E.; Kolodziejczyk, N.

    2013-05-01

    The flow through the Gulf of Mexico is an integral part of the North Atlantic Ocean Subtropical Gyre Circulation, known to be forced by the wind over the North Atlantic and by an equivalent contribution from the inter-hemispheric Meridional Overturning Cell. To the North Atlantic Circulation, the Gulf represents an important energy and vorticity sink through the particular behavior of the Loop Current within. Comprehending the structure and dynamics of the Loop Current System (which includes the Yucatan Current (YC), Loop Current (LC), the shedding of anticyclonic Loop Current Eddies (LCE) and peripheral cyclonic gyres) is fundamental for understanding the circulation in the entire Gulf. Within the Gulf, the eastern Loop Current and the western Campeche Bay (CB) regions are characterized by persistent eddy structures, with less structured eddy fields in between. Of these later ones, the northwestern Gulf is a geostrophic turbulence area, constantly perturbed by LCE, which represents, at the same time, an important dissipation and circulation forcing region for the Western Gulf. Important processes recently investigated that will be discussed: 1) The generation and maintenance of the Geostrophic Turbulence field in the north western Gulf. 2) The circulation in deep water induced by the surface geostrophic turbulence field. 3) The generation of intensive jets at depth by interaction of +/- gyres. 4) The generation of coastal trap waves by the interaction of LCEs with the western shelf. 5) The generation of deep topographic Roosby waves by topographic interactions of the LCEs with topography. 5) The characteristics of the Bay of Campeche Circulation, The Campeche Gyre and its interaction with LCEs. 6) The Gulf's response to the passage of hurricanes. 7) The trapping of inertial waves by the LCEs and the related enhanced mixing.

  1. Summary Report on Information Technology Integration Activities For project to Enhance NASA Tools for Coastal Managers in the Gulf of Mexico and Support Technology Transfer to Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Gulbransen, Thomas C.

    2009-04-27

    Deliverable to NASA Stennis Space Center summarizing summarizes accomplishments made by Battelle and its subcontractors to integrate NASA's COAST visualization tool with the Noesis search tool developed under the Gulf of Mexico Regional Collaborative project.

  2. Northern Gulf Coast Digital Elevation Model

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA's National Geophysical Data Center (NGDC) is building high-resolution digital elevation models (DEMs) for select U.S. coastal regions in the Gulf of Mexico....

  3. Alkenone-based temperature patterns along the eastern South Pacific Coastal Ocean: the effect of upwelling and advection on the sedimentary alkenone unsaturation-index (U37K'

    Directory of Open Access Journals (Sweden)

    J. Garcés-Vargas

    2010-01-01

    Full Text Available We report that the sedimentary record of alkenone unsaturation-index (U37K' in the eastern South Pacific displays a wide range of temperatures, in response to sea surface temperature (SST, as well as nutrient concentrations. The U37K' inshore-offshore trend shows low-correlation with SSTs at many transitional sites (50–200 km offshore, and in one oligotrophic coastal site (~20° S. In contrast, in open-ocean sites SSTs play the expected dominant role. The latitudinal trend shows that nitrate, phosphate and/or temperature affect distinctively the U37K', suggesting progressive high-impacts in areas with permanent nutrient-stress conditions (~20° S, which is consistent with previous experiments. In contrast, this impact is slightly and not observable in transitional and open-ocean areas, respectively, where the coupling between offshore propagation of mesoscale eddies and upwelling filaments supply additional chlorophyll/nutrient. This study is a first field approximation to the impacts of thermal/non-thermal factors over the unsaturation-index in eastern Boundary Current systems, which would help in future temperature reconstructions.

  4. Spartina alterniflora alters ecosystem DMS and CH4 emissions and their relationship along interacting tidal and vegetation gradients within a coastal salt marsh in Eastern China

    Science.gov (United States)

    Wang, Jinxin; Wang, Jinshu

    2017-10-01

    Invasive Spartina alterniflora accumulates organic carbon rapidly and can utilize a wide range of potential precursors for dimethyl sulfide (DMS) production, as well as a wide variety of methanogenic substrates. Therefore, we predicted that S. alterniflora invasion would alter the relationships between DMS and methane (CH4) fluxes along the interacting gradients of tidal influence and vegetation, as well as the ecosystem-atmosphere exchange of DMS and CH4. In this study, we used static flux chambers to measure DMS and CH4 fluxes in August (growing season) and December (non-growing season) of 2013, along creek and vegetation transects in an Eastern Chinese coastal salt marsh. S. alterniflora invasion dramatically increased DMS and CH4 emission rates by 3.8-513.0 and 2.0-127.1 times the emission rates within non-vegetated regions and regions populated with native species, respectively, and significantly altered the spatial distribution of DMS and CH4 emissions. We also observed a substantial amount of variation in the DMS and CH4 fluxes along the elevation gradient in the salt marsh studied. A significant relationship between DMS and CH4 fluxes was observed, with the CH4 flux passively related to the DMS flux. The correlation between CH4 and DMS emissions along the vegetation transects was more significant than along the tidal creek. In the S. alterniflora salt marsh, the relationship between DMS and CH4 fluxes was more significant than within any other salt marsh. Additionally, CH4 emissions within the S. alterniflora salt marsh were more sensitive to the variation in DMS emissions than within any other vegetation zone. The spatial variability in the relationship observed between DMS and CH4 fluxes appears to be at least partly due to the alteration of substrates involved in DMS and CH4 by S. alterniflora invasion. In the S. alterniflora salt marsh, methanogenesis was more likely to be derived from non-competitive substrates than competitive substrates, but within

  5. Propagation mechanisms of incident tsunami wave in Jiangsu coastal area, caused by eastern Japan earthquake on March 11, 2011

    Science.gov (United States)

    Yuan, Chun-guang; Wang, Yi-gang; Huang, Hui-ming; Chen, Cheng; Chen, Da-ke

    2016-03-01

    At 13:46 on March 11, 2011 (Beijing time), an earthquake of Mw=9.0 occurred in Japan. By comparing the tsunami data from Guanhekou marine station with other tsunami wave observation gathered from southeast coastal area of China, it was evident that, only in Guanhekou, the position of the maximum wave height appeared in the middle part rather than in the front of the tsunami wave train. A numerical model of tsunami propagation based on 2-D nonlinear shallow water equations was built to study the impact range and main causes of the special tsunami waveform discovered in Jiangsu coastal area. The results showed that nearly three-quarters of the Jiangsu coastal area, mainly comprised the part north of the radial sand ridges, reached its maximum tsunami wave height in the middle part of the wave train. The main cause of the special waveform was the special underwater topography condition of the Yellow Sea and the East China Sea area, which influenced the tsunami propagation and waveform significantly. Although land boundary reflection brought an effect on the position of the maximum wave height to a certain extent, as the limits of the incident waveform and distances between the observation points and shore, it was not the dominant influence factor of the special waveform. Coriolis force's impact on the tsunami waves was so weak that it was not the main cause for the special phenomenon in Jiangsu coastal area. The study reminds us that the most destructive wave might not appear in the first one in tsunami wave train.

  6. Propagation Mechanisms of Incident Tsunami Wave in Jiangsu Coastal Area, Caused by Eastern Japan Earthquake on March 11, 2011

    Institute of Scientific and Technical Information of China (English)

    袁春光; 王义刚; 黄惠明; 陈橙; 陈大可

    2016-01-01

    At 13:46 on March 11, 2011 (Beijing time), an earthquake of Mw=9.0 occurred in Japan. By comparing the tsunami data from Guanhekou marine station with other tsunami wave observation gathered from southeast coastal area of China, it was evident that, only in Guanhekou, the position of the maximum wave height appeared in the middle part rather than in the front of the tsunami wave train. A numerical model of tsunami propagation based on 2-D nonlinear shallow water equations was built to study the impact range and main causes of the special tsunami waveform discovered in Jiangsu coastal area. The results showed that nearly three-quarters of the Jiangsu coastal area, mainly comprised the part north of the radial sand ridges, reached its maximum tsunami wave height in the middle part of the wave train. The main cause of the special waveform was the special underwater topography condition of the Yellow Sea and the East China Sea area, which influenced the tsunami propagation and waveform significantly. Although land boundary reflection brought an effect on the position of the maximum wave height to a certain extent, as the limits of the incident waveform and distances between the observation points and shore, it was not the dominant influence factor of the special waveform. Coriolis force’s impact on the tsunami waves was so weak that it was not the main cause for the special phenomenon in Jiangsu coastal area. The study reminds us that the most destructive wave might not appear in the first one in tsunami wave train.

  7. A Study on a Snowband Associated with a Coastal Front and Cold-Air Damming Event of 3-4 February 1998 along the Eastern Coast of the Korean Peninsula

    Institute of Scientific and Technical Information of China (English)

    Jae-Gyoo LEE; Ming XUE

    2013-01-01

    A 24-h simulation with the Advanced Regional Prediction System (ARPS) nonhydrostatic model is performed for the heavy snowfall event of 3 4 February 1998 along the eastern coast of Korean Peninsula;the results are used to understand the snowfall process,including why the precipitation maxima formed along the Yeongdong coastal region rather than over the mountain slope and ridge top during.The numerical simulation with a 4-km horizontal grid spacing and 43 levels reproduces very well the narrow snowband located off the eastern Korean coast,away from,instead of over,the Yeongdong coastal mountain range.The general evolution of the snowband agrees quite well with radar observations,while the water-equivalent precipitation amount agrees reasonably well with radar precipitation estimate.The simulation results clearly show that the snow band developed due to the lifting by a coastal front th atdeveloped because of the damming of cold air against the eastern slope of the coastal mountain range.The damming was enhanced by the advection of cold air by a low-level inountain-parallel jet from the north,formed due to geostrophic adjustnent as the on-shore upslope air was decelerated by the mountain blocking.As the onshore flow weakened later due to synoptic-scale flow pattern change,the cold front propagated off shore and the precipitation dissipated.

  8. Reconstruction of hazard-related geomorphic events from mixed-volcanoclastic sequences in the Campanian coastal area (Eastern Tyrrhenian Sea)

    Science.gov (United States)

    Violante, Crescenzo; Esposito, Eliana; Molisso, Flavia; Porfido, Sabina; Sacchi, Marco

    2010-05-01

    Sudden emplacement of large amount of pyroclastic material from explosive eruptions represents a significant interference with the geomorphic system, both for inland and coastal areas. Large volcanocalstic activity can induce sediment overburden and consequent return to the equilibrium profile by means of land degradation and erosional processes. Volcaniclastic resedimentation and generation of mass flows and floods are common phenomena affecting wide areas near the volcanic vents, occurring either soon after volcanic eruptions and during inter-eruption periods. In volcanic coastal areas volcanic debris can enter the sea in the form of avalanche deposits, hyper-concentrated flows or as the underwater continuation of subaerial flows and surges. Rapid accumulation at sea of tephra deposits from explosive eruptions can led to seafloor failure or act as weak layers for successive gravity deformations. Yet, part of volcaniclastic material can be stored in the catchments and be available for erosion a long time after an eruption. In the study area sediment availability strictly relate to massive and intermittent volcaniclastic delivery, largely responsible for aggradation/progradation of the coastal area during the Quaternary. The discussed hazard-related sedimentary features include large aprons of avalanche deposits off volcanic structures, steep sedimentary progradations at mouth of bedrock streams and small rivers, sediment re-mobilization in pro-delta areas, and shallow slides. Marine geophysical surveys and sea-land correlations led to associate such features with volcanic processes including the Mt. Epomeo uplift at Ischia island, the collapse of the Somma-Vesuvius caldera and the emplacement of pyroclastics from Phlegrean Fields and Somma-Vesuvius.

  9. Sandwaves of the Gulf of Khambhat

    Digital Repository Service at National Institute of Oceanography (India)

    Vora, K.H.; Gujar, A.R.; Karisiddaiah, S.M.

    In the Gulf of Khambhat (Gujarat, India) the best formed sandwaves are seen in the west close to the Eastern Sand Bank. With increasing clay content and clay cover of the sea bed, the sandwaves become poorly formed. In the southern part of the Gulf...

  10. Holocene vegetational and coastal environmental changes from the Lago Crispim record in northeastern Pará State, eastern Amazonia.

    Science.gov (United States)

    Behling, H; Lima da Costa, M

    2001-04-01

    Vegetational and coastal environmental changes have been interpreted from a 600cm long and 764014C yr B.P. old sediment core from Lago Crispim located in the northeastern Pará State in northern Brazil. The radiocarbon dated sediment core was studied by multi-element geochemistry, pollen and charcoal analysis.Holocene Atlantic sea-level rise caused an elevation of local water table, which allowed the formation of organic deposits in a probably former inter-dune valley. Dense, diverse and tall Amazon rain forest, and some restinga (coastal vegetation) covered the study area at the beginning of the record at 764014C yr B.P. Mangrove vegetation developed along rivers close to the core site at that time. Subsequent decrease in less mangrove vegetation near the study site indicates a sea-level regression, beginning since around 700014C yr B.P. Lower sea-levels probably favoured the formation of a local Mauritia/Mauritiella palm swamp at 662014C yr B.P. Oscillations of higher and lower sea-level stands probably changed the size of the local palm swamp area several times between 6620 and 363014C yr B.P. Sea-level transgression at around 363014C yr B.P., caused marked coastal environmental changes: the development of mangroves near the site, the replacement of the local palm swamp by a Cyperaceae swamp, the substitution of the surrounding former Amazon rain forest and some restinga vegetation mainly by salt marshes. High amount carbonised particles suggest a strong human impact by burning on the coastal ecosystems during this late Holocene period.Highest concentrations of NaCl and also Ca, Mg and K in the upper sediment core indicate that the Atlantic was close during the late Holocene period. The core site, which is today 500m from the coastline and only 1-2m above modern sea-level, was apparently never reached by marine excursions during the Holocene.Less representation of mangrove since ca. 184014C yr B.P., may be related due to a slightly lower sea-level or to human

  11. Coastal vulnerability to sea-level rise: a preliminary database for the U.S. Atlantic, Pacific, and Gulf of Mexico coasts

    Science.gov (United States)

    Hammar-Klose, Erika S.; Thieler, E. Robert

    2001-01-01

    The prediction of coastal evolution is not straightforward. There is no standard methodology, and even the kind of data required to make such predictions are the subject of much scientific debate. Since a viable, quantitative predictive model for coastal evolution is not available. The relative susceptibility of the Nation's coastline to sea-level rise is quantified here at a regional to national scale using basic information on coastal geomorphology, rate of sea-level rise, past shoreline evolution and other factors. This approach combines the coastal system's susceptibility to change with its natural ability to adapt to changing environmental and conditions, and yields a relative measure of the system's natural vulnerability to the effects of sea-level rise. This information has immediate application to many of the decisions our society will be making regarding coastal development in both the short- and long-term.

  12. Investigation of heavy metal pollution in eastern Aegean Sea coastal waters by using Cystoseira barbata, Patella caerulea, and Liza aurata as biological indicators.

    Science.gov (United States)

    Aydın-Önen, S; Öztürk, M

    2017-01-19

    In order to have an extensive contamination profile of heavy metal levels (Cd, Cu, Fe, Mn, Ni, Pb, and Zn), seawater, sediment, Patella caerulea, Cystoseira barbata, and Liza aurata were investigated by using inductively coupled plasma-atomic emission spectrometry (ICP-AES). Samples were collected from five coastal stations along the eastern Aegean Sea coast (Turkey) on a monthly basis from July 2002 through May 2003. According to the results of this study, heavy metal levels were arranged in the following sequence: Fe > Pb > Zn > Mn > Ni > Cu > Cd for water, Fe > Cu > Mn > Ni > Zn > Pb > Cd for sediment, Fe > Zn > Mn > Pb > Ni > Cd > Cu for C. barbata, Fe > Zn > Mn > Ni > Pb > Cu > Cd for P. caerulea, and Fe > Zn > Mn > Cu > Ni > Pb > Cd for L. aurata. Moreover, positive relationships between Fe in water and Mn in water, Fe in sediment and Mn in sediment, Fe in C. barbata and Mn in C. barbata, Fe in P. caerulea and Mn in P. caerulea, and Fe in L. aurata and Mn in L. aurata may suggest that these metals could be originated from the same anthropogenic source. C. barbata represented with higher bioconcentration factor (BCF) values, especially for Fe, Mn, and Zn values. This observation may support that C. barbata can be used as an indicator species for the determinations of Fe, Mn, and Zn levels. Regarding Turkish Food Codex Regulation's residue limits, metal values in L. aurata were found to be lower than the maximum permissible levels issued by Turkish legislation and also the recommended limits set by FAO/WHO guidelines. The results of the investigation indicated that P. caerulea, L. aurata, and especially C. barbata are quantitative water-quality bioindicators and biomonitoring subjects for biologically available metal accumulation for Aegean Sea coastal waters.

  13. Mussels (Mytilus galloprovincialis) as a bio-indicator species in radioactivity monitoring of Eastern Adriatic coastal waters.

    Science.gov (United States)

    Krmpotić, Matea; Rožmarić, Martina; Barišić, Delko

    2015-06-01

    Croatian Adriatic coastal waters are systematically monitored within the Mediterranean Mussel Watch Project using mussels (Mytilus galloprovincialis) as a bio-indicator species. The study includes determination of naturally occurring ((7)Be, (40)K, (232)Th, (226)Ra and (238)U), as well as anthropogenic (137)Cs radionuclides. Activity concentrations in dry weight of mussels' soft tissue along the Croatian Adriatic coast are presented, with spatial and seasonal variations given and discussed. Samples were collected in spring and autumn for the period between 2009 and 2013. Radionuclides were determined by gamma-ray spectrometry. Activity concentrations of (7)Be were the highest in spring periods, especially in the areas with significant fresh water discharges. Activity concentrations of (40)K did not vary significantly with season or location. (137)Cs activities were low, while (232)Th, (226)Ra and (238)U activities were mostly below the detection limit of performed gamma-spectrometric measurement.

  14. Species profiles: Life histories and environmental requirements of coastal fishes and invertebrates (South Florida): Southern, gulf, and summer flounders. [Paralichthys lethostigma; Paralichthys albigutta; Paralichthys dentatus

    Energy Technology Data Exchange (ETDEWEB)

    Gilbert, C.R.

    1986-07-01

    The southern, gulf, and summer flounders live most of their lives in or near estuaries. Adults migrate into offshore waters during fall and winter, where spawning occurs from September to April. Eggs and newly-hatched larvae are carried inshore into estuaries, where further growth takes place. Age at sexual maturity for the three species has been estimated from 2 to 4 years, and maximum longevity from 3 to 10 years. Females apparently live slightly longer than males. Southern and summer flounders are estimated to live slightly longer than the smaller gulf flounder. Postlarvae eat mostly zooplankton, and larger individuals feed on fish and crustaceans. The summer and gulf flounders prefer a hard and/or sandy substrate, whereas the southern flounder is more common in a soft bottom of rich organic mud, clay, or silt. The southern flounder, unlike the other two species, is highly euryhaline, and frequently occurs in fresh water. Commercial catch statistics lump the three species together under the name ''flounder.'' Peak commercial catch in the Gulf of Mexico (in 1977) was 1.5 million lb, for a value of $561,000; peak catch in the south Atlantic region (also in 1977) was 11.4 million lb, for a value of $5,100,000.

  15. Long-range transportation of anthropogenic aerosols over eastern coastal region of India: Investigation of sources and impact on regional climate change

    Science.gov (United States)

    Das, S. K.; Jayaraman, A.

    2012-11-01

    Estimation of the effect of long-range transportation of anthropogenic aerosols in India is a real challenge due to the strong influence of local sources. This study addresses this issue from the measurements of aerosol optical and physical properties during 16-31 March 2006 at Kalpakkam (12.56° N and 80.12° E), a remote eastern coastal station in India. Increased anthropogenic aerosols were observed due to long-range transport from Indo-Gangetic Basin (IGB) in comparison to two other sources: central Bay of Bengal (CBoB) and northern Indian Ocean (NIO) as grouped from back-trajectory analyses of air parcels. AOD is found to be maximum of about 0.32 during IGB wind regime followed by CBoB (0.27) and NIO (0.20) winds. MODIS observed AOD is found to be high all along the wind back-trajectories connected from IGB indicating IGB as a source. Black carbon (BC) during IGB wind (2.0 μg·m- 3) is 65% greater than that observed during NIO wind (1.2 μg·m- 3). As a result, single scattering albedo becomes as low as 0.89 during IGB wind while 0.92 during NIO wind. These long-range transported aerosols cause about 65% enhancement of atmospheric radiative forcing and consequently, aerosol heating rate is also increased by about 70% during IGB wind regime (0.36 K/day) compared to NIO wind regime (0.21 K/day). Being a coastal region, Kalpakkam experiences strong diurnal variation of aerosol properties due to land and sea breezes that introduce about 30% increase of atmospheric forcing during land breeze by short-range transport of BC from nearby urban region. The present study concludes that long-range transported anthropogenic aerosols over coastal region of India cause significant enhancement of regional aerosol radiative forcing and their heating effect can have significant consequences for regional climate change by altering hydrological cycle over the tropical continental area.

  16. Mesoscale circulation along the Sakhalin Island eastern coast

    Science.gov (United States)

    Prants, Sergey V.; Andreev, Andrey G.; Uleysky, Michael Yu.; Budyansky, Maxim V.

    2017-02-01

    The seasonal and interannual variability of mesoscale circulation along the eastern coast of the Sakhalin Island in the Okhotsk Sea is investigated using the AVISO velocity field and oceanographic data for the period from 1993 to 2016. It is found that mesoscale cyclones with the horizontal dimension of about 100 km occur there predominantly during summer, whereas anticyclones occur predominantly during fall and winter. The cyclones are generated due to a coastal upwelling forced by northward winds and the positive wind stress curl along the Sakhalin coast. The anticyclones are formed due to an inflow of low-salinity Amur River waters from the Sakhalin Gulf intensified by southward winds and the negative wind stress curl in the cold season. The mesoscale cyclones support the high biological productivity at the eastern Sakhalin shelf in July- August.

  17. Mesoscale circulation along the Sakhalin Island eastern coast

    CERN Document Server

    Prants, S V; Budyansky, M V; Uleysky, M Yu

    2016-01-01

    The seasonal and interannual variability of mesoscale circulation along the eastern coast of the Sakhalin Island in the Okhotsk Sea is investigated using AVISO velocity field and oceanographic data for the period from 1993 to 2016. It is found that mesoscale cyclones with the horizontal dimension of about 100 km occur there predominantly during summer, whereas anticyclones occur predominantly during fall and winter. The cyclones are generated due to the coastal upwelling forced by northward winds and the positive wind stress curl along the Sakhalin coast. The anticyclones are formed due to an inflow of low-salinity Amur-River waters from the Sakhalin Gulf intensified by southward winds and the negative wind stress curl in the cold season. The mesoscale cyclones support the high biological productivity at the eastern Sakhalin shelf in July - August.

  18. Numerical simulation of tides and tidal currents in the Beibu Gulf and Guangxi coastal areas%北部湾及广西近海潮流数值模拟

    Institute of Scientific and Technical Information of China (English)

    施华斌; 牛小静; 余锡平

    2012-01-01

    该文采用二维浅水模型模拟分析了北部湾海域潮流系统,并在此基础上建立了广西沿海一、二维耦合水动力模型,模型中考虑了广西沿岸6条主要入海河流对近岸水动力的影响,进一步分析了广西近海海域潮致余流场及其对近海污染物输移扩散的影响。模型潮位计算值和实测值符合良好。结果显示:K1分潮在北部湾口形成一个逆时针旋转潮波系统,M2分潮在湾顶越南海防附近形成逆时针旋转潮波系统,广西近海海域K1分潮占优。广西沿海海域内,离岸较近的海域余流场相对较强,余流速度受浅水效应及湾口等地形缩窄影响而增强;离岸较远海域余流明显减弱,水体交换能力降低。%A two dimensional numerical model was used to simulate the tides in the Beibu Gulf. A 1 13 and 2 D coupled numerical model was then used to simulate the tidal currents to analyze pollutant transport in Guangxi coastal areas, north of the Beibu Gulf. The simulations of the tides and tidal currents are in good agreement with observationss. In the Beibu Gulf, K1 is a counterclockwise rotating system with the amphidromic point located in the baymouth. M2 is also a counterclockwise rotating system with the amphidromic point in the north, close to Hal Phong, Vietnam. ]n the Guangxi coastal areas, the tide-induced residual currents in the areas near the shore are much stronger than those further away. The shallow water and narrowed baymouth strengthen the residual currents.

  19. National Assessment of Hurricane-Induced Coastal Erosion Hazards: Gulf of Mexico Bradenton Beach to Clearwater Beach, Florida Raw (non-interpolated) Beach Slope Point Data

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The National Assessment of Coastal Change Hazards project derives beach morphology features from lidar elevation data for the purpose of understanding and...

  20. National Assessment of Hurricane-Induced Coastal Erosion Hazards: Gulf of Mexico Bradenton Beach to Clearwater Beach, Florida Mean (interpolated) Beach Slope Point Data

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The National Assessment of Coastal Change Hazards project derives beach morphology features from lidar elevation data for the purpose of understanding and...

  1. National Assessment of Hurricane-Induced Coastal Erosion Hazards: Gulf of Mexico Bradenton Beach to Clearwater Beach, Florida Raw (non-interpolated) Beach Slope Point Data

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The National Assessment of Coastal Change Hazards project derives beach morphology features from lidar elevation data for the purpose of understanding and predicting...

  2. Marine pollution risk in a coastal city: use of an eco-genotoxic tool as a stress indicator in mussels from the Eastern Aegean Sea.

    Science.gov (United States)

    Kacar, Asli; Pazi, Idil; Gonul, Tolga; Kucuksezgin, Filiz

    2016-08-01

    Coastal areas, such as bays, estuaries, and harbors, are heavily polluted since these areas are the settlements to which toxic chemicals from industrial and domestic wastes are discharged. The genetic damage was evaluated using bioindicator mussel Mytilus galloprovincialis caused by toxic chemicals (metals and polycyclic aromatic hydrocarbons) in İzmir and Çandarlı Bays (the Eastern Aegean Sea) through comet assay. Three sampling sites from the two bays were selected and the study was conducted during the spring and autumn periods. The highest levels of DNA damage expressed as %Tail-DNA were observed in İzmir Bay (34.60 % Tail-DNA) in the spring. Analysis of the correlation between PAHs and metals in mussels and %T-DNA in the hemolymph and gill cells showed a statistically significant positive correlation between %T-DNA and ∑PAH, chromium (p llution level of the İzmir and Çandarlı Bays by using the DNA damage to the mussel, which can identify the effects of environmental pollutants at the cellular levels. These results confirm that comet assay can be used to determine the temporal and spatial differences of DNA damage, and as a suitable tool for the measurement of genotoxicity in regions with low pollutant concentrations.

  3. Condition of South-Eastern Baltic Sea Shores and Methods of Protecting Them

    Science.gov (United States)

    Ostrowski, Rafał; Pruszak, Zbigniew; Babakov, Alexander

    2014-06-01

    The paper describes lithodynamic and morphodynamic processes occurring in the main part of the south-eastern Baltic coastal area, namely on the sea shores from the Vistula mouth in the Gulf of Gdansk to the Lithuanian-Latvian border. The study area is subject to intensive natural coastal changes, as well as shore evolution caused by anthropogenic impacts at several locations. Methods of coastal protection against erosion and shore stabilization systems applied in the past and currently are described. The paper deals with the causes of the dynamics of beach/dune shores and cliffs. It presents the authors' field observations of 2010-2013, as well as previously gained knowledge and the results of Polish, Russian and joint Polish-Russian field surveys.

  4. Eastern Gulf of Mexico, February 1996 to June 1997 Average Ocean Currents, Geographic NAD83, MMS (1999) [ocean_currents_egom_AVG_MMS_1997

    Data.gov (United States)

    Louisiana Geographic Information Center — This is one data set of a data package consisting of thirteen point data sets that have as attributes the direction and velocity of ocean currents in the 'eastern'...

  5. Evidence That the Deepwater Horizon Oil Spill Caused Changes in Seasonal Mean Trace Metal Concentrations in Bottom Sediment Retrieved from the Eastern Outer Continental Shelf (OCS), Gulf of Mexico

    Science.gov (United States)

    Steffy, D. A.; Nichols, A.; Morgan, J.

    2014-12-01

    Higher nickel, vanadium, and lead concentrations measured in sea bottom sediment of the eastern OCS can be explained by the presence of a new source for these metals from the damaged Mconco Well which resulted in the BP Deepwater Horizon Oil Spill during the spring of 2010. Sixty-five sediment samples were collected during the fall months for the years 2008-2011 from the eastern OCS. The Tukey range test was used to compare six metal concentrations between the relict sand deposits of the northern Gulf OCS to the relict carbonate sediments off of western Florida OCS. Tests indicated that nickel, vanadium, and lead were significantly higher (p < 0.05) in the seasonal mean concentrations in the relict sand deposits. These higher concentrations are also reflected in the vanadium to nickel ratio being statistically different (p < 0.005) for carbonate sediment (1.70 ± 0.24) when compared to relict sand (0.96 ± 0.12) in the north, which is closer to the damaged well. This difference indicates a new source of nickel that accumulated through time in the north. In the carbonate sediment there appears a zonation of the ratios with a dependency on water depth. The V/Ni ratio is 0.80 ± 0.10 for samples taken in water depths at or deeper than 200 m; and ratios are 2.06 ±0.42 for samples taken in water depths shallower than 200 m.

  6. 2012 NOAA Office for Coastal Management Coastal Inundation Digital Elevation Model: Mobile/Tallahassee (AL/FL) WFO - Okaloosa (portion), Walton, Bay, Gulf, Franklin (portion), and Wakulla (portion) Counties

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This digital elevation model (DEM) is a part of a series of DEMs produced for the National Oceanic and Atmospheric Administration Office for Coastal Management's Sea...

  7. Eutrophication-induced acidification of coastal waters in the northern Gulf of Mexico: Insights into origin and processes from a coupled physical-biogeochemical model

    Science.gov (United States)

    Laurent, Arnaud; Fennel, Katja; Cai, Wei-Jun; Huang, Wei-Jen; Barbero, Leticia; Wanninkhof, Rik

    2017-01-01

    Nutrient inputs from the Mississippi/Atchafalaya River system into the northern Gulf of Mexico promote high phytoplankton production and lead to high respiration rates. Respiration coupled with water column stratification results in seasonal summer hypoxia in bottom waters on the shelf. In addition to consuming oxygen, respiration produces carbon dioxide (CO2), thus lowering the pH and acidifying bottom waters. Here we present a high-resolution biogeochemical model simulating this eutrophication-driven acidification and investigate the dominant underlying processes. The model shows the recurring development of an extended area of acidified bottom waters in summer on the northern Gulf of Mexico shelf that coincides with hypoxic waters. Not reported before, acidified waters are confined to a thin bottom boundary layer where the production of CO2 by benthic metabolic processes is dominant. Despite a reduced saturation state, acidified waters remain supersaturated with respect to aragonite.

  8. "Economic heritage impact assessment" as a tool for evaluating the impacts on the great requalification project of the coastal cities, Unesco sites. The case study of Torre Annunziata, in the gulf of Naples

    Directory of Open Access Journals (Sweden)

    Mariarosaria Angrisano

    2015-06-01

    Full Text Available This article starts from the study of the historic port cities, that today are facing the challenge of the urban waterfront requalification, through the preservation of the cultural and landscape heritage. The recommendations on the “Historic Urban Landscape”, and the operating tools promoted by the ICOMOS “Guidance on Heritage Impact Assessments for Cultural World Heritage Properties” of 2011, configure themselves as the most recent dispositions regarding the preservation, protection and enhancement of the cultural heritage (Fusco Girard, 2010. The ICOMOS Guide it was considered the most suitable tool for evaluating the impacts of the big requalification project of the urban waterfront on the cultural heritage. To fully understand this tool it was made an application for evaluating the impacts of Pompeii Great Project on the waterfront of Torre Annunziata, a coastal city in the Gulf of Naples, UNESCO Site. After this analysis phase it follows a reflection on how to improve the Heritage Impact Assessment as a tool able to evaluate not only the cultural impacts, but also the economic ones, so we can speak of “economy of the cultural heritage”. The last proposal is that of supporting the process of “Heritage Impact Assessment” with an evaluation of economic impacts, through an analysis of costs/benefits, for estimating in a monetary terms, the benefit of the investments into the preservation of the historic urban heritage of the coastal cities, proposing an “Economic Heritage Impact Assessment” (EHIA. This method was elaborated from the author, into the PHD thesis “The Historic Urban Landscape of the coastal cities: challenges and opportunities”. The case of Torre Annunziata offers the possibility to overcome the mere evaluation of the cultural impacts proposed by the ICOMOS.

  9. High xenodiversity versus low native diversity in the south-eastern Mediterranean: bryozoans from the coastal zone of Lebanon

    Directory of Open Access Journals (Sweden)

    J. G. HARMELIN

    2016-02-01

    Full Text Available Because of its location in the warmest corner of the Mediterranean, its proximity to the northern entrance of the Suez Canal, i.e. the gateway for massive exotic biota introduction into the Mediterranean, the occurrence of high shipping activity and strong human pressure, the Lebanese coastal zone is an area that is exceptionally well-suited for investigating the effects of these extreme conditions on Mediterranean biodiversity. Bryozoans, which are among the main components of sessile communities, reflect dramatically the impact of these particular conditions. Their assemblages, sampled by diving along the whole coast of Lebanon during a pluriannual programme, mainly between 1999 and 2003, consist of 93 species (12 Cyclostomata, 2 Ctenostomata, 79 Cheilostomata. The native part of this bryozoan fauna exhibits low diversity, with an unexpected absence of many taxa, from family to species level, which are very common in the rest of the Mediterranean. It is also characterized by a high proportion of endemic species, in contrast with the general eastward trend of decreasing endemicity observed in the Mediterranean, and by the strong presence of 'southern' thermophilic species. With 27 non-indigenous species, xenodiversity is exceptionally high, particularly in the cheilostome pool (26 species, but was likely undersampled. Moreover, one may assume that new non-indigenous bryozoans (NIB are now established along the Levantine coasts. This trend is expected to increase in the near future with the intensification of surface water warming and boost of shipping activity and propagule flux generated by the expansion of the Suez Canal.

  10. Aerosol Size, CCN, and Black Carbon Properties at a Coastal Site in the Eastern U.S.

    Science.gov (United States)

    Royalty, T. M.; Petters, M. D.; Grieshop, A. P.; Meskhidze, N.; Reed, R. E.; Phillips, B.; Dawson, K. W.

    2015-12-01

    Atmospheric aerosols play an important role in regulating the global radiative budget through direct and indirect effects. To date, the role of sea spray aerosols in modulating climate remains poorly understood. Here we present results from measurements performed at the United States Army Corps of Engineers' Field Research Facility in Duck, North Carolina, USA. Aerosol mobility size distributions (10-600 nm), refractory black carbon (rBC) and scattering particle size distributions (200-620 nm), and size resolved cloud condensation nuclei distributions (.07% - .6% supersaturation) were collected at the end of a 560m pier. Aerosol characteristics associated with northerly, high wind speed (15+ m s-1) flow originating from an oceanic trajectory are contrasted with aerosol properties observed during a weak to moderate westerly flow originating from a continental trajectory. Both marine and continental air masses had aerosol with bi-modal number size distributions with modes centered at 30nm and 140nm. In the marine air-mass, the CCN concentration at supersaturation of 0.4%, total aerosol number, surface, and volume concentration were low. rBC number concentration (D > 200 nm) associated with the marine air-mass was an order of magnitude less than continental number concentration and indicative of relatively unpolluted air. These measurements are consistent with measurements from other coastal sites under marine influence. The relative proportion of Aitken mode size particles increased from 1:2 to 2:1 while aerosol surface area was < 25 μm2 cm-3, suggesting that conditions upwind were potentially conducive to new particle formation. Overall, these results will contribute a better understanding to composition and size variation of marine aerosols.

  11. Assessment of the environmental status in Hellenic coastal waters (Eastern Mediterranean: from the Water Framework Directive to the Marine Strategy Water Framework Directive.

    Directory of Open Access Journals (Sweden)

    N. SIMBOURA

    2014-11-01

    Full Text Available A  methodology is presented to assess the environmental status sensu the Marine Strategy Water Framework Directive (MSFD based on data obtained from the monitoring of water quality in the Hellenic coastal waters within the Water Framework Directive (WFD.   An adapted decision tree used for integrating the results of the WFD in the Basque country was applied. Modifications lie to the evaluation of the physicochemical status based on a eutrophication index developed for Eastern Mediterranean waters. Results on hydromorphological, physicochemical and biological elements are presented. The chemical status was evaluated based on measurements of heavy metals in water. The evaluation of the biological quality was based on the use of metrics developed for phytoplankton biomass, benthic macroinvertebrates and macroalgae updated to accommodate MSFD needs. Results on the integrative status of the water bodies were validated by correlating classification results with a pressure index and environmental indicators in water column and sediment. Following this decision tree the majority of stations expected to be at risk of achieving the good status were found in moderate status. Benthos was found to be the element with the closest agreement with the integrated final status having an increased weighting in the decision tree. The quality of benthos and in some  limited cases  the eutrophication index determined largely the final status. The highest disagreement with the integrative classification was produced by macroalgae. All indicators used correlated with water and sediment parameters but benthos correlated better with sediment factors while phytoplankton and eutrophication index with water column parameters.

  12. Assessment of the environmental status in Hellenic coastal waters (Eastern Mediterranean: from the Water Framework Directive to the Marine Strategy Water Framework Directive.

    Directory of Open Access Journals (Sweden)

    N. SIMBOURA

    2015-01-01

    Full Text Available A  methodology is presented to assess the environmental status sensu the Marine Strategy Water Framework Directive (MSFD based on data obtained from the monitoring of water quality in the Hellenic coastal waters within the Water Framework Directive (WFD.   An adapted decision tree used for integrating the results of the WFD in the Basque country was applied. Modifications lie to the evaluation of the physicochemical status based on a eutrophication index developed for Eastern Mediterranean waters. Results on hydromorphological, physicochemical and biological elements are presented. The chemical status was evaluated based on measurements of heavy metals in water. The evaluation of the biological quality was based on the use of metrics developed for phytoplankton biomass, benthic macroinvertebrates and macroalgae updated to accommodate MSFD needs. Results on the integrative status of the water bodies were validated by correlating classification results with a pressure index and environmental indicators in water column and sediment. Following this decision tree the majority of stations expected to be at risk of achieving the good status were found in moderate status. Benthos was found to be the element with the closest agreement with the integrated final status having an increased weighting in the decision tree. The quality of benthos and in some  limited cases  the eutrophication index determined largely the final status. The highest disagreement with the integrative classification was produced by macroalgae. All indicators used correlated with water and sediment parameters but benthos correlated better with sediment factors while phytoplankton and eutrophication index with water column parameters.

  13. Polycyclic aromatic hydrocarbons in the coastal water, surface sediment and mullet Liza klunzingeri from northern part of Hormuz strait (Persian Gulf).

    Science.gov (United States)

    Bastami, Kazem Darvish; Afkhami, Majid; Ehsanpour, Maryam; Kazaali, Aida; Mohammadizadeh, Maria; Haghparast, Sarah; Soltani, Farzaneh; Zanjani, Seyed Asal; Ghorghani, Nasrin Farzaneh; Pourzare, Roya

    2013-11-15

    The concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) were determined in mullet (Liza klunzingeri), water and sediment from northern part of Hormuz strait (Persian Gulf). The concentration levels of total PAHs in L. klunzingeri, water and sediment were 133.99-268.57 ng g(-1)dry weight, 3.12-5.88 ng l(-1) and 42.29-228.9 ng g(-1) dry weight, respectively. Based on isomer ratios, analysis of the PAHs source in the sediment demonstrated that the PAHs come from pyrogenic and petrogenic origin. Risk assessment showed PAHs threshold concentrations to occasionally be exceeded in the study area.

  14. Thermohaline processes in a tropical coastal zone

    Science.gov (United States)

    Enriquez, Cecilia; Mariño-Tapia, Ismael; Jeronimo, Gilberto; Capurro-Filograsso, Luis

    2013-10-01

    The detailed thermohaline structure of the northern Yucatan coastal zone was obtained for the first time in order to gain an insight into the interactions between various processes in this complex tropical environment of extreme evaporation and high precipitation rates. From the continent, it has water exchange with numerous coastal lagoons (ranging from brackish to hypersaline) and receives intense submarine groundwater discharges (SGD). In the summer of 2006 a high-resolution (500 m cross-shore and 5 km along-shore) oceanographic campaign was performed starting at Holbox Island down to the mouth of Celestun Lagoon. CTD profiles were measured at 1020 stations along 69 coastal cross-shore transects. Additionally, CTD data from 2 wider surveys, covering the continental shelf (Campeche Bank) and the southern Gulf of Mexico respectively were used to complement the results. From the thermohaline properties, two main water masses were identified: (a) the Caribbean Subtropical Underwater (CSUW), upwelled from the Caribbean, which was observed at the bottom very close to the coast in more than 260 km (from the upwelling region near Cape Catoche to approximately 89.5 W during the summer of 2006) and (b) the second dominant group was a mass of warm hypersaline water which originates in Yucatan due to the high temperature and evaporation rates. We call this water mass the Yucatan Sea Water (YSW) after finding evidence of its presence in various field campaigns both in the Yucatan Sea and further to the west in the southern Gulf of Mexico. All the water masses present in the Yucatan coastal zone showed pronounced variations with important dilution and salinisation effects. The permeable karstic geology of the region prevents the continental water from discharging into the ocean through surface rivers and instead the rainfall permeates directly to the aquifer and travels through caves and fractures towards the sea. Three main regions showed evidence of continental discharges

  15. Quantitative analysis of the impacts of terrestrial environmental factors on precipitation variation over the Beibu Gulf Economic Zone in Coastal Southwest China

    Science.gov (United States)

    Zhao, Yinjun; Deng, Qiyu; Lin, Qing; Cai, Chunting

    2017-03-01

    Taking the Guangxi Beibu Gulf Economic Zone as the study area, this paper utilizes the geographical detector model to quantify the feedback effects from the terrestrial environment on precipitation variation from 1985 to 2010 with a comprehensive consideration of natural factors (forest coverage rate, vegetation type, terrain, terrestrial ecosystem types, land use and land cover change) and social factors (population density, farmland rate, GDP and urbanization rate). First, we found that the precipitation trend rate in the Beibu Gulf Economic Zone is between ‑47 and 96 mm/10a. Second, forest coverage rate change (FCRC), urbanization rate change (URC), GDP change (GDPC) and population density change (PDC) have a larger contribution to precipitation change through land-surface feedback, which makes them the leading factors. Third, the human element is found to primarily account for the precipitation changes in this region, as humans are the active media linking and enhancing these impact factors. Finally, it can be concluded that the interaction of impact factor pairs has a significant effect compared to the corresponding single factor on precipitation changes. The geographical detector model offers an analytical framework to reveal the terrestrial factors affecting the precipitation change, which gives direction for future work on regional climate modeling and analyses.

  16. A laboratory-incubated redox oscillation experiment to investigate Hg fluxes from highly contaminated coastal marine sediments (Gulf of Trieste, Northern Adriatic Sea).

    Science.gov (United States)

    Emili, A; Carrasco, L; Acquavita, A; Covelli, S

    2014-03-01

    Mercury (Hg) mobility at the sediment-water interface was investigated during a laboratory incubation experiment conducted with highly contaminated sediments (13 μg g(-1)) of the Gulf of Trieste. Undisturbed sediment was collected in front of the Isonzo River mouth, which inflows Hg-rich suspended material originating from the Idrija (NW Slovenia) mining district. Since hypoxic and anoxic conditions at the bottom are frequently observed and can influence the Hg biogeochemical behavior, a redox oscillation was simulated in the laboratory, at in situ temperature, using a dark flux chamber. Temporal variations of several parameters were monitored simultaneously: dissolved Hg (DHg) and methylmercury (MeHg), O2, NH4 (+), NO3 (-) + NO2 (-), PO4 (3-), H2S, dissolved Mn(2+), dissolved inorganic and organic carbon (DIC and DOC). Under anoxic conditions, both Hg (665 ng m(2) day(-1)) and MeHg (550 ng m(2) day(-1)) fluxed from sediments into the water column, whereas re-oxygenation caused concentrations of MeHg and Hg to rapidly drop, probably due to re-adsorption onto Fe/Mn-oxyhydroxides and enhanced demethylation processes. Hence, during anoxic events, sediments of the Gulf of Trieste may be considered as an important source of DHg species for the water column. On the contrary, re-oxygenation of the bottom compartment mitigates Hg and MeHg release from the sediment, thus acting as a natural "defence" from possible interaction between the metal and the aquatic organisms.

  17. Coastal processes of the Russian Baltic - modern trends, driving forces and human impact

    Science.gov (United States)

    Ryabchuk, Daria; Sivkov, Vadim; Kovaleva, Olga; Sergeev, Alexander; Zhamoida, Vladimir; Dorokhov, Dmitry

    2016-04-01

    In frame of EMODNET-geology project and Russian Science Foundation (project 14-37-00047), the Coastal Behavior maps for the Russian parts of Baltic were compiled. Several areas of the Baltic Sea coastal zone were chosen as case studies for more detailed mapping and analyses. According to annual observations rates of coastal erosion within some areas of the easternmost part of the Gulf of Finland are recently accelerated due to both natural (increasing of the extreme storm events frequency, accompanied by high water level) and anthropogenic (impact of St. Petersburg Flood Protection Facility, submarine sand mining, ineffective coast protection etc.) factors. The geological and geomorphic factors determine the long-term coastal zone development. The coasts mostly consist of easily erodible Quaternary deposits (clays and sands). They evolve under overall sediment deficiency. Moreover, some specific, small-scale features of the near-shore bottom, found by investigations using multibeam and side-scan sonar study, play a very important role in the entire erosion process. Average rates of coastal erosion is 0.5-1.0 m/year, but during the extreme storms, coastal escarpment can retreat for the distance up to 5 m at once. During late autumn and winter seasons of 2006-2007, 2011-2012 and 2013 years severe storms caused extreme erosion events damaged the coastal dunes with forming of active escarpment, destruction of coast protection and recreation infrastructure, complete transformation of sand accretion spits. In the southern coastal zone of the Gulf processes of long-shore sand waves occurred. Prognoses of coastal processes development based on annual observations (since 2004), remote sensing data analyses and modeling has shown that depending on different climate change scenarios coastal line of the study area can retreat for the distance from 50 to 100 m. The most intense coastal processes of the Russian part of the South-Eastern Baltic are observe within attached part of

  18. New Orleans, Louisiana Coastal Digital Elevation Model

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA's National Geophysical Data Center (NGDC) is building high-resolution digital elevation models (DEMs) for select U.S. coastal regions in the Gulf of Mexico....

  19. Mobile, Alabama Coastal Digital Elevation Model

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA's National Geophysical Data Center (NGDC) is building high-resolution digital elevation models (DEMs) for select U.S. coastal regions in the Gulf of Mexico....

  20. Panama City, Florida Coastal Digital Elevation Model

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NOAA's National Geophysical Data Center (NGDC) is building high-resolution digital elevation models (DEMs) for select U.S. coastal regions in the Gulf of Mexico....

  1. Basin Analysis of the Mississippi Interior Salt Basin and Petroleum System Modeling of the Jurassic Smackover Formation, Eastern Gulf Coastal Plain

    Energy Technology Data Exchange (ETDEWEB)

    Mancini, Ernest A.

    2003-02-06

    The project objectives are improving access to information for the Mississippi Interior Salt Basin by inventorying data files and records of the major information repositories in the region, making these inventories easily accessible in electronic format, increasing the amount of information available on domestic sedimentary basins through a comprehensive analysis of the Mississippi Interior Salt Basin, and enhancing the understanding of the petroleum systems operating in the Mississippi Interior Salt Basin.

  2. Coupling centennial-scale shoreline change to sea-level rise and coastal morphology in the Gulf of Mexico using a Bayesian network

    Science.gov (United States)

    Plant, Nathaniel G.; Robert Thieler, E.; Passeri, Davina L.

    2016-05-01

    Predictions of coastal evolution driven by episodic and persistent processes associated with storms and relative sea-level rise (SLR) are required to test our understanding, evaluate our predictive capability, and to provide guidance for coastal management decisions. Previous work demonstrated that the spatial variability of long-term shoreline change can be predicted using observed SLR rates, tide range, wave height, coastal slope, and a characterization of the geomorphic setting. The shoreline is not sufficient to indicate which processes are important in causing shoreline change, such as overwash that depends on coastal dune elevations. Predicting dune height is intrinsically important to assess future storm vulnerability. Here, we enhance shoreline-change predictions by including dune height as a variable in a statistical modeling approach. Dune height can also be used as an input variable, but it does not improve the shoreline-change prediction skill. Dune-height input does help to reduce prediction uncertainty. That is, by including dune height, the prediction is more precise but not more accurate. Comparing hindcast evaluations, better predictive skill was found when predicting dune height (0.8) compared with shoreline change (0.6). The skill depends on the level of detail of the model and we identify an optimized model that has high skill and minimal overfitting. The predictive model can be implemented with a range of forecast scenarios, and we illustrate the impacts of a higher future sea-level. This scenario shows that the shoreline change becomes increasingly erosional and more uncertain. Predicted dune heights are lower and the dune height uncertainty decreases.

  3. Coupling centennial-scale shoreline change to sea-level rise and coastal morphology in the Gulf of Mexico using a Bayesian network

    Science.gov (United States)

    Plant, Nathaniel G.

    2016-01-01

    Predictions of coastal evolution driven by episodic and persistent processes associated with storms and relative sea-level rise (SLR) are required to test our understanding, evaluate our predictive capability, and to provide guidance for coastal management decisions. Previous work demonstrated that the spatial variability of long-term shoreline change can be predicted using observed SLR rates, tide range, wave height, coastal slope, and a characterization of the geomorphic setting. The shoreline is not suf- ficient to indicate which processes are important in causing shoreline change, such as overwash that depends on coastal dune elevations. Predicting dune height is intrinsically important to assess future storm vulnerability. Here, we enhance shoreline-change predictions by including dune height as a vari- able in a statistical modeling approach. Dune height can also be used as an input variable, but it does not improve the shoreline-change prediction skill. Dune-height input does help to reduce prediction uncer- tainty. That is, by including dune height, the prediction is more precise but not more accurate. Comparing hindcast evaluations, better predictive skill was found when predicting dune height (0.8) compared with shoreline change (0.6). The skill depends on the level of detail of the model and we identify an optimized model that has high skill and minimal overfitting. The predictive model can be implemented with a range of forecast scenarios, and we illustrate the impacts of a higher future sea-level. This scenario shows that the shoreline change becomes increasingly erosional and more uncertain. Predicted dune heights are lower and the dune height uncertainty decreases.

  4. Meiofauna, microflora and geochemical properties of the late quaternary (Holocene) core sediments in the Gulf of Izmir (Eastern Aegean Sea, Turkey)

    Science.gov (United States)

    Yümün, Zeki Ü.; Meriç, Engin; Avşar, Niyazi; Nazik, Atike; Barut, İpek F.; Yokeş, Baki; Sagular, Enis K.; Yildiz, Ayşegül; Eryilmaz, Mustafa; Kam, Erol; Başsari, Asiye; Sonuvar, Bora; Dinçer, Feyza; Baykal, Kubilay; Kaya, Seyhan

    2016-12-01

    The Gulf of Izmir has seen the construction of marinas at four locations; Karşıyaka, Bayraklı, İnciraltı and Urla (Çeşmealtı). Six drilling holes have been structured for each location. Morphological abnormities observed in foraminifer tests, obtained from these core drillings, and coloring encountered in both foraminifer tests and ostracod carapeces, provide evidence of natural and unnatural environmental pollution. The objectives of this study are to identify micro and macro fauna, foraminifers in particular, contained within sediments in the above-mentioned locations; to investigate the background of pollution in the Gulf Region; and to determine pollution's impact upon benthic foraminifer and ostracods. Çeşmealtı foraminifera tests did not lead to color and morphological changes. But foraminifera tests samples collected from Karşıyaka, Bayraklı and İnciraltı led them to turn black (Plate 4-6). However, concentrations of heavy metals (Ni, Cr and Mn) obtained from the sediments of Karşıyaka, Bayraklı and İnciraltı locations are higher than those obtained from the Çeşmealtı samples and high concentrations of these elements may be the cause of the color change in the samples during the foraminifera tests. In Karşıyaka and Bayraklı ostracod samples, Bosquetina carinella, Pterygocythereis jonesi, Semicytherura species; in the Çeşmealtı/Urla zone, Cyprideis torosa; in İnciraltı, Pseudopsammocythere reniformis; and in four zones, Loxoconcha and Xestoleberis species were observed in the range of relative frequency. The same analyses were done on nannoplankton but they did not lead to color and morphological changes.

  5. Vertical Movements and Patterns in Diving Behavior of Whale Sharks as Revealed by Pop-Up Satellite Tags in the Eastern Gulf of Mexico.

    Science.gov (United States)

    Tyminski, John P; de la Parra-Venegas, Rafael; González Cano, Jaime; Hueter, Robert E

    2015-01-01

    The whale shark (Rhincodon typus) is a wide-ranging, filter-feeding species typically observed at or near the surface. This shark's sub-surface habits and behaviors have only begun to be revealed in recent years through the use of archival and satellite tagging technology. We attached pop-up satellite archival transmitting tags to 35 whale sharks in the southeastern Gulf of Mexico off the Yucatan Peninsula from 2003-2012 and three tags to whale sharks in the northeastern Gulf off Florida in 2010, to examine these sharks' long-term movement patterns and gain insight into the underlying factors influencing their vertical habitat selection. Archived data were received from 31 tags deployed on sharks of both sexes with total lengths of 5.5-9 m. Nine of these tags were physically recovered facilitating a detailed long-term view into the sharks' vertical movements. Whale sharks feeding inshore on fish eggs off the northeast Yucatan Peninsula demonstrated reverse diel vertical migration, with extended periods of surface swimming beginning at sunrise followed by an abrupt change in the mid-afternoon to regular vertical oscillations, a pattern that continued overnight. When in oceanic waters, sharks spent about 95% of their time within epipelagic depths (500 m) that largely occurred during daytime or twilight hours (max. depth recorded 1,928 m), had V-shaped depth-time profiles, and comprised more rapid descents (0.68 m sec-1) than ascents (0.50 m sec-1). Nearly half of these extreme dives had descent profiles with brief but conspicuous changes in vertical direction at a mean depth of 475 m. We hypothesize these stutter steps represent foraging events within the deep scattering layer, however, the extreme dives may have additional functions. Overall, our results demonstrate complex and dynamic patterns of habitat utilization for R. typus that appear to be in response to changing biotic and abiotic conditions influencing the distribution and abundance of their prey.

  6. Two new species of Elopicola (Digenea: Aporocotylidae) from Hawaiian ladyfish, Elops hawaiensis (Eastern Sea) and Atlantic tarpon, Megalops atlanticus (Gulf of Mexico) with a comment on monophyly of elopomorph blood flukes.

    Science.gov (United States)

    Orélis-Ribeiro, Raphael; Halanych, Kenneth M; Dang, Binh T; Bakenhaster, Micah D; Arias, Cova R; Bullard, Stephen A

    2017-06-01

    Elopicola bristowi sp. n. infects the blood vascular system of Hawaiian ladyfish, Elops hawaiensis, in the Eastern Sea. It differs from the only nominal congener Elopicola nolancribbi by the combination of having rows of ventrolateral tegumental spines, a proportionally long oesophagus, anterior caeca, vasa efferentia coalescing ventral to the posterodextral margin of the testis, a post-testicular metraterm, a dextral common genital pore lateral to the oötype, and genitalia that are enantiomorphic relative to those of E. nolancribbi. Elopicola franksi sp. n. infects the heart and blood vascular system of Atlantic tarpon, Megalops atlanticus, in the Gulf of Mexico. It differs from its congeners by the combination of lacking ventrolateral tegumental spines and having an elongate body (6× longer than wide), a proportionally long oesophagus, a compact testis at level of the distal ends of the posterior caeca, and a post-testicular common genital pore at level of the oötype. Phylogenetic analyses based on the small subunit ribosomal DNA (18S), large subunit ribosomal DNA (28S), and internal transcribed spacer 2 (ITS2) genes revealed considerable genetic differences between these taxa. The 18S+28S tree showed a monophyletic Elopicola sister to all aporocotylids infecting fishes of Euteleosteomorpha. The ITS2 tree showed Paracardicoloides yamagutii as the sister taxon to Elopicola spp.

  7. Recent evolution of surge-related events and assessment of coastal flooding risk on the eastern coasts of the English Channel

    Science.gov (United States)

    Pirazzoli, Paolo Antonio; Costa, Stéphane; Dornbusch, Uwe; Tomasin, Alberto

    2006-12-01

    This paper is based on statistical analysis of hourly tide measurements for some 285 equivalent full years from the stations of Weymouth, Bournemouth, Portsmouth, Newhaven, Dover and Sheerness in the UK, and of Cherbourg, Le Havre, Dieppe, Boulogne, Calais and Dunkirk in France. For each tidal value, surge heights have been determined and correlated with hourly or three-hourly wind and air pressure data from nearby meteorological stations. Major surges in the area are generally produced by storms associated with wind from north-west or south-west that tend to push oceanic water into the Channel. Recent medium-term climate evolution does not seem to increase the flooding risk at French stations, where surge-related winds tend to decrease in frequency and speed (Cherbourg, Dieppe and Boulogne) or show little change (Le Havre). However, the long-term risk of flooding will increase through the loss in land elevation due to a continuation of the local relative sea-level rise, especially if this effect will be enhanced by an acceleration in the global sea-level rise predicted by climatic models. The northern side of the Channel (Weymouth, Bournemouth and Portsmouth) is mainly exposed to southerly winds that show variable trends. It is also apparently affected by strong subsidence trends during the last two decades. If lasting, such trends can only increase long-term flooding risk. The flooding risk has not increased near the eastern end of the Channel. The duration of significant cyclonic events tends to decrease near Cherbourg but tends to increase near Weymouth, with no conclusive trends in other stations (Portsmouth, Calais and Dunkirk), where extreme surges may occur also in relatively high-air-pressure situations. In conclusion, medium-term coastal flooding risk seems to increase especially at Weymouth, Bournemouth and Portsmouth, and also, but less so, at Le Havre and Sheerness. In addition, few extreme surges occurred during the last decades at the time of spring

  8. NOAA marine environmental buoy data from the National Data Buoy Center in the Gulf of Alaska, Gulf of Mexico, Bering Sea, North Atlantic Ocean, North Pacific Ocean, Coastal Waters of SE Alaska, Coastal Waters of Western U.S., Great Lakes, North American Coastline-North, and North American Coastline-South from 2002-10-01 to 2002-10-31 (NCEI Accession 0000400)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Pressure, temperature, and other data were collected from fixed platforms in the Gulf of Alaska, Gulf of Mexico, Bering Sea, North Atlantic Ocean, North Pacific...

  9. Vertical Movements and Patterns in Diving Behavior of Whale Sharks as Revealed by Pop-Up Satellite Tags in the Eastern Gulf of Mexico.

    Directory of Open Access Journals (Sweden)

    John P Tyminski

    Full Text Available The whale shark (Rhincodon typus is a wide-ranging, filter-feeding species typically observed at or near the surface. This shark's sub-surface habits and behaviors have only begun to be revealed in recent years through the use of archival and satellite tagging technology. We attached pop-up satellite archival transmitting tags to 35 whale sharks in the southeastern Gulf of Mexico off the Yucatan Peninsula from 2003-2012 and three tags to whale sharks in the northeastern Gulf off Florida in 2010, to examine these sharks' long-term movement patterns and gain insight into the underlying factors influencing their vertical habitat selection. Archived data were received from 31 tags deployed on sharks of both sexes with total lengths of 5.5-9 m. Nine of these tags were physically recovered facilitating a detailed long-term view into the sharks' vertical movements. Whale sharks feeding inshore on fish eggs off the northeast Yucatan Peninsula demonstrated reverse diel vertical migration, with extended periods of surface swimming beginning at sunrise followed by an abrupt change in the mid-afternoon to regular vertical oscillations, a pattern that continued overnight. When in oceanic waters, sharks spent about 95% of their time within epipelagic depths (500 m that largely occurred during daytime or twilight hours (max. depth recorded 1,928 m, had V-shaped depth-time profiles, and comprised more rapid descents (0.68 m sec-1 than ascents (0.50 m sec-1. Nearly half of these extreme dives had descent profiles with brief but conspicuous changes in vertical direction at a mean depth of 475 m. We hypothesize these stutter steps represent foraging events within the deep scattering layer, however, the extreme dives may have additional functions. Overall, our results demonstrate complex and dynamic patterns of habitat utilization for R. typus that appear to be in response to changing biotic and abiotic conditions influencing the distribution and abundance of their

  10. Vertical Movements and Patterns in Diving Behavior of Whale Sharks as Revealed by Pop-Up Satellite Tags in the Eastern Gulf of Mexico

    Science.gov (United States)

    Tyminski, John P.; de la Parra-Venegas, Rafael; González Cano, Jaime; Hueter, Robert E.

    2015-01-01

    The whale shark (Rhincodon typus) is a wide-ranging, filter-feeding species typically observed at or near the surface. This shark’s sub-surface habits and behaviors have only begun to be revealed in recent years through the use of archival and satellite tagging technology. We attached pop-up satellite archival transmitting tags to 35 whale sharks in the southeastern Gulf of Mexico off the Yucatan Peninsula from 2003–2012 and three tags to whale sharks in the northeastern Gulf off Florida in 2010, to examine these sharks’ long-term movement patterns and gain insight into the underlying factors influencing their vertical habitat selection. Archived data were received from 31 tags deployed on sharks of both sexes with total lengths of 5.5–9 m. Nine of these tags were physically recovered facilitating a detailed long-term view into the sharks’ vertical movements. Whale sharks feeding inshore on fish eggs off the northeast Yucatan Peninsula demonstrated reverse diel vertical migration, with extended periods of surface swimming beginning at sunrise followed by an abrupt change in the mid-afternoon to regular vertical oscillations, a pattern that continued overnight. When in oceanic waters, sharks spent about 95% of their time within epipelagic depths (500 m) that largely occurred during daytime or twilight hours (max. depth recorded 1,928 m), had V-shaped depth-time profiles, and comprised more rapid descents (0.68 m sec-1) than ascents (0.50 m sec-1). Nearly half of these extreme dives had descent profiles with brief but conspicuous changes in vertical direction at a mean depth of 475 m. We hypothesize these stutter steps represent foraging events within the deep scattering layer, however, the extreme dives may have additional functions. Overall, our results demonstrate complex and dynamic patterns of habitat utilization for R. typus that appear to be in response to changing biotic and abiotic conditions influencing the distribution and abundance of their prey

  11. Ocean Observing Public-Private Collaboration to Improve Tropical Storm and Hurricane Predictions in the Gulf of Mexico

    Science.gov (United States)

    Perry, R.; Leung, P.; McCall, W.; Martin, K. M.; Howden, S. D.; Vandermeulen, R. A.; Kim, H. S. S.; Kirkpatrick, B. A.; Watson, S.; Smith, W.

    2016-02-01

    In 2008, Shell partnered with NOAA to explore opportunities for improving storm predictions in the Gulf of Mexico. Since, the collaboration has grown to include partners from Shell, NOAA National Data Buoy Center and National Center for Environmental Information, National Center for Environmental Prediction, University of Southern Mississippi, and the Gulf of Mexico Coastal Ocean Observing System. The partnership leverages complementary strengths of each collaborator to build a comprehensive and sustainable monitoring and data program to expand observing capacity and protect offshore assets and Gulf communities from storms and hurricanes. The program combines in situ and autonomous platforms with remote sensing and numerical modeling. Here we focus on profiling gliders and the benefits of a public-private partnership model for expanding regional ocean observing capacity. Shallow and deep gliders measure ocean temperature to derive ocean heat content (OHC), along with salinity, dissolved oxygen, fluorescence, and CDOM, in the central and eastern Gulf shelf and offshore. Since 2012, gliders have collected 4500+ vertical profiles and surveyed 5000+ nautical miles. Adaptive sampling and mission coordination with NCEP modelers provides specific datasets to assimilate into EMC's coupled HYCOM-HWRF model and 'connect-the-dots' between well-established Eulerian metocean measurements by obtaining (and validating) data between fixed stations (e.g. platform and buoy ADCPs) . Adaptive sampling combined with remote sensing provides satellite-derived OHC validation and the ability to sample productive coastal waters advected offshore by the Loop Current. Tracking coastal waters with remote sensing provides another verification of estimate Loop Current and eddy boundaries, as well as quantifying productivity and analyzing water quality on the Gulf coast, shelf break and offshore. Incorporating gliders demonstrates their value as tools to better protect offshore oil and gas assets

  12. Trends in marine debris in the U.S. Caribbean and the Gulf of Mexico, 1996-2003

    Science.gov (United States)

    Ribic, Christine; Seba B. Sheavly,; Rugg, David J.

    2011-01-01

    .S. Caribbean. Lower magnitude decreases were seen in indicator debris along the eastern Gulf of Mexico. In contrast, only land-based indicators declined in the western Gulf of Mexico; total, ocean-based and general-source indicators remained unchanged. Decreases in land-based indicators were not related to human population in the coastal regions; human population increased in all regions over the time of the study. Significant monthly patterns for indicator debris were found only in the Gulf of Mexico; counts were highest during May through September, with peaks occurring in July. Inclement weather conditions before the time of the survey also accounted for some of the variation in the western Gulf of Mexico; fewer items were found when there were heavy seas or cold fronts in the weeks prior to the survey, while tropical storms (including hurricanes) increased the amount of debris. With the development around the globe of long-term monitoring programs using standardized methodology, there is the potential to help management at individual sites, as well as generate larger-scale perspectives (from regional to global) to inform decision makers. Incorporating mechanisms producing debris into marine debris programs would be a fruitful area for future research.

  13. Groundwater dynamic, temperature and salinity response to the tide in Patagonian marshes: Observations on a coastal wetland in San José Gulf, Argentina

    Science.gov (United States)

    Alvarez, María del Pilar; Carol, Eleonora; Hernández, Mario A.; Bouza, Pablo J.

    2015-10-01

    The processes regulating the relationship between tidal flows and shallow groundwater dynamics, temperature and salinity in a coastal wetland in an arid climate are analysed in a detailed field study carried out in the marsh located at Playa Fracasso (Argentina). The continuous records of groundwater level, temperature and electrical conductivity from a transect perpendicular to the coastline were studied during a period ranging from summer to winter, together with the information obtained in hydrogeomorphological field surveys and soil profiles. An assessment of the processes conditioning marsh hydrology was carried out contemplating seasonal (summer-winter) and periodical variations caused by tidal flows. The study showed that the dynamics of groundwater in relation to tidal flows depends almost exclusively on the infiltration of tidal water when the marsh is flooded during spring tides (syzygy), with an increase in the groundwater discharge level at the onset of syzygy. The differences in temperature between sea and continental water were very useful in defining the origin of the different contributions. Groundwater salinity is mainly associated with the leaching of the soil salts that enter with the sea water infiltrating during flood events. The presence of saline soils in the marsh is regulated by the evapotranspiration predominating in arid zones. The conceptual hydrological model suggested may help in the understanding of the hydrological processes in other similar marshes of Patagonia, as well as in coastal wetlands of arid zones worldwide.

  14. Identifying Drivers of Collective Action for the Co-management of Coastal Marine Fisheries in the Gulf of Nicoya, Costa Rica.

    Science.gov (United States)

    García Lozano, Alejandro J; Heinen, Joel T

    2016-04-01

    Small-scale fisheries are important for preventing poverty, sustaining local economies, and rural livelihoods, but tend to be negatively impacted by traditional forms of management and overexploitation among other factors. Marine Areas for Responsible Fishing (Áreas Marinas de Pesca Responsable, AMPR) have emerged as a new model for the co-management of small-scale fisheries in Costa Rica, one that involves collaboration between fishers, government agencies, and NGOs. The primary objective of this paper is to elucidate some of the key variables that influence collective action among small-scale fishers in Tárcoles, a community in the Gulf of Nicoya. We examined collective action for the formation of a local marketing cooperative and participation in management through the AMPR. We apply the social-ecological framework as a diagnostic and organizational tool in the analysis of several types of qualitative data, including interviews with key informants, informal interviews, legal documents, and gray literature. Findings illustrate the importance of socio-economic community attributes (e.g., group size, homogeneity, previous cooperation), as well as that of social (e.g., equity) and ecological (e.g., improved stocks) outcomes perceived as favorable by actors. In addition, our work demonstrates the importance of certain kinds of external NGOs for facilitating and sustaining collective action.

  15. Numerical Modeling of the Effects of Nutrient-rich Coastal-water Input on the Phytoplankton in the Gulf of California

    Science.gov (United States)

    Bermudez, A.; Rivas, D.

    2015-12-01

    Phytoplankton bloom dynamics depends on the interactions of favorable physical, chemical, and biotic conditions, particularly on the available nutrients that enhance phytoplankton growth, like nitrogen. Costal and estuarine environments are heavily influenced by exogenous sources of nitrogen; the anthropogenic inputs include urban and rural wastewater coming from agricultural activities (i.e., fertilizers and animal waste). In response, new production is often enhanced, leading eutrophication and phytoplankton blooms, including harmful taxa. These events have become more frequent, and with it the interest to evaluate their effects on marine ecosystems and the impact on human health. In the Gulf of California the harmful algal blooms (HABs) had affected aquaculture, fisheries, and even tourism, thereby it is important to generate information about biological and physical factors that can influence their appearance. A numerical model is a tool that may bring key information about the origin and distribution of phytoplankton blooms. Herein the analysis is based on a three-dimensional, hydrodynamical numerical model, coupled to a Nitrogen-Phytoplankton-Zooplankton-Detritus (NPZD) model. Several numerical simulations using different forcing and scenarios are carried out in order to evaluate the processes that influence the phytoplankton growth. These numerical results are compared to available observations. Thus, the main environmental factors triggering the generation of HABs can be identified.

  16. Identifying Drivers of Collective Action for the Co-management of Coastal Marine Fisheries in the Gulf of Nicoya, Costa Rica

    Science.gov (United States)

    García Lozano, Alejandro J.; Heinen, Joel T.

    2016-04-01

    Small-scale fisheries are important for preventing poverty, sustaining local economies, and rural livelihoods, but tend to be negatively impacted by traditional forms of management and overexploitation among other factors. Marine Areas for Responsible Fishing (Áreas Marinas de Pesca Responsable, AMPR) have emerged as a new model for the co-management of small-scale fisheries in Costa Rica, one that involves collaboration between fishers, government agencies, and NGOs. The primary objective of this paper is to elucidate some of the key variables that influence collective action among small-scale fishers in Tárcoles, a community in the Gulf of Nicoya. We examined collective action for the formation of a local marketing cooperative and participation in management through the AMPR. We apply the social-ecological framework as a diagnostic and organizational tool in the analysis of several types of qualitative data, including interviews with key informants, informal interviews, legal documents, and gray literature. Findings illustrate the importance of socio-economic community attributes (e.g., group size, homogeneity, previous cooperation), as well as that of social (e.g., equity) and ecological (e.g., improved stocks) outcomes perceived as favorable by actors. In addition, our work demonstrates the importance of certain kinds of external NGOs for facilitating and sustaining collective action.

  17. Ecotoxicological effects of POPs on ariidae Ariopsis felis (Linnaeus, 1766) from three coastal ecosystems in the Southern Gulf of Mexico and Yucatan Peninsula.

    Science.gov (United States)

    Zapata-Pérez, Omar; Ceja-Moreno, Victor; Olmos, Mónica Roca; Pérez, María Teresa; Río-García, Marcela Del; Yarto, Mario; Mendoza-Cantú, Ania; Ize-Lema, Ana-Irina; Gavilán-García, Arturo; Felipe, Sánchez-Teyer L; Gold-Bouchot, Gerardo

    2007-08-01

    Persistent Organic Pollutants (POPs) are still used for agricultural and disease vector control, as well as for industrial purposes. In the last decades, various studies have shown that fish are sensitive to the toxicological effects of certain POPs, including a large class of endocrine- disrupting chemicals (EDCs). In the present study, the relationship between of POPs and their effects using vitellogenin gene expression as biomarker of effect in hardhead catfish Ariopsis felis (Linnaeus, 1766) from three ecosystems in the Southern Gulf of Mexico and Yucatan Peninsula are discussed. Contaminant results showed that median concentrations of PCBs, HCHs, DDTs and Chlordanes were higher in Laguna de Terminos with respect to Celestun and Dzilam. In the same way, the vitellogenin gene expression was clearly over-expressed in fish collected from Terminos Lagoon. Principal Component Analysis showed that vitellogenin gene expression is related to the concentrations of total DDTs and PCBs, and negatively related to total Drins. Overall, this study represents the first tests exploring changes in molecular diagnostic indicators following exposure of several organic compounds in our country. Vitellogenin gene expressions associated with some endocrine disruptors detected in Terminos Lagoon were measured and we can now report clear changes in fish exposed.

  18. Trophic transfer and accumulation of mercury in ray species in coastal waters affected by historic mercury mining (Gulf of Trieste, northern Adriatic Sea).

    Science.gov (United States)

    Horvat, Milena; Degenek, Nina; Lipej, Lovrenc; Snoj Tratnik, Janja; Faganeli, Jadran

    2014-03-01

    Total mercury (Hg) and monomethylmercury (MMHg) were analysed in the gills, liver and muscle of four cartilaginous fish species (top predators), namely, the eagle ray (Myliobatis aquila), the bull ray (Pteromylaeus bovinus), the pelagic stingray (Dasyatis violacea) and the common stingray (Dasyatis pastinaca), collected in the Gulf of Trieste, one of the most Hg-polluted areas in the Mediterranean and worldwide due to past mining activity in Idrija (West Slovenia). The highest Hg and MMHg concentrations expressed on a dry weight (d.w.) basis were found in the muscle of the pelagic stingray (mean, 2.529 mg/kg; range, 1.179-4.398 mg/kg, d.w.), followed by the bull ray (mean, 1.582 mg