Measuring Land Change in Coastal Zone around a Rapidly Urbanized Bay

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Faming Huang

2018-05-01

Full Text Available Urban development is a major cause for eco-degradation in many coastal regions. Understanding urbanization dynamics and underlying driving factors is crucial for urban planning and management. Land-use dynamic degree indices and intensity analysis were used to measure land changes occurred in 1990, 2002, 2009, and 2017 in the coastal zone around Quanzhou bay, which is a rapidly urbanized bay in Southeast China. The comprehensive land-use dynamic degree and interval level intensity analysis both revealed that land change was accelerating across the three time intervals in a three-kilometer-wide zone along the coastal line (zone A, while land change was fastest during the second time interval 2002–2009 in a separate terrestrial area within coastal zone (zone B. Driven by urbanization, built-up gains and cropland losses were active for all time intervals in both zones. Mudflat losses were active except in the first time interval in zone A due to the intensive sea reclamation. The gain of mangrove was active while the loss of mangrove is dormant for all three intervals in zone A. Transition level analysis further revealed the similarities and differences in processes within patterns of land changes for both zones. The transition from cropland to built-up was systematically targeted and stationary while the transition from woodland to built-up was systematically avoiding transition in both zones. Built-up tended to target aquaculture for the second and third time intervals in zone A but avoid Aquaculture for all intervals in zone B. Land change in zone A was more significant than that in zone B during the second and third time intervals at three-level intensity. The application of intensity analysis can enhance our understanding of the patterns and processes in land changes and suitable land development plans in the Quanzhou bay area. This type of investigation is useful to provide information for developing sound land use policy to achieve urban

Measuring Land Change in Coastal Zone around a Rapidly Urbanized Bay.

Science.gov (United States)

Huang, Faming; Huang, Boqiang; Huang, Jinliang; Li, Shenghui

2018-05-23

Urban development is a major cause for eco-degradation in many coastal regions. Understanding urbanization dynamics and underlying driving factors is crucial for urban planning and management. Land-use dynamic degree indices and intensity analysis were used to measure land changes occurred in 1990, 2002, 2009, and 2017 in the coastal zone around Quanzhou bay, which is a rapidly urbanized bay in Southeast China. The comprehensive land-use dynamic degree and interval level intensity analysis both revealed that land change was accelerating across the three time intervals in a three-kilometer-wide zone along the coastal line (zone A), while land change was fastest during the second time interval 2002⁻2009 in a separate terrestrial area within coastal zone (zone B). Driven by urbanization, built-up gains and cropland losses were active for all time intervals in both zones. Mudflat losses were active except in the first time interval in zone A due to the intensive sea reclamation. The gain of mangrove was active while the loss of mangrove is dormant for all three intervals in zone A. Transition level analysis further revealed the similarities and differences in processes within patterns of land changes for both zones. The transition from cropland to built-up was systematically targeted and stationary while the transition from woodland to built-up was systematically avoiding transition in both zones. Built-up tended to target aquaculture for the second and third time intervals in zone A but avoid Aquaculture for all intervals in zone B. Land change in zone A was more significant than that in zone B during the second and third time intervals at three-level intensity. The application of intensity analysis can enhance our understanding of the patterns and processes in land changes and suitable land development plans in the Quanzhou bay area. This type of investigation is useful to provide information for developing sound land use policy to achieve urban sustainability in

Future trends in urbanization and coastal water pollution in the Bay of Bengal: the lived experience

NARCIS (Netherlands)

Zinia, N.J.; Kroeze, C.

2015-01-01

The Bay of Bengal includes coastal seas of several countries, including Bangladesh, India, and Myanmar. We present scenarios for future river export of eutrophying nutrients into the Bay of Bengal, and the role of urbanization therein. We used NEWS (Nutrient Export from WaterSheds) model to analyze

Crustal structure of the coastal and marine San Francisco Bay region, California

Science.gov (United States)

Parsons, Tom

2002-01-01

As of the time of this writing, the San Francisco Bay region is home to about 6.8 million people, ranking fifth among population centers in the United States. Most of these people live on the coastal lands along San Francisco Bay, the Sacramento River delta, and the Pacific coast. The region straddles the tectonic boundary between the Pacific and North American Plates and is crossed by several strands of the San Andreas Fault system. These faults, which are stressed by about 4 cm of relative plate motion each year, pose an obvious seismic hazard.

Optimization of a Coastal Environmental Monitoring Network Based on the Kriging Method: A Case Study of Quanzhou Bay, China

Science.gov (United States)

Chen, Kai; Ni, Minjie; Wang, Jun; Huang, Dongren; Chen, Huorong; Wang, Xiao; Liu, Mengyang

2016-01-01

Environmental monitoring is fundamental in assessing environmental quality and to fulfill protection and management measures with permit conditions. However, coastal environmental monitoring work faces many problems and challenges, including the fact that monitoring information cannot be linked up with evaluation, monitoring data cannot well reflect the current coastal environmental condition, and monitoring activities are limited by cost constraints. For these reasons, protection and management measures cannot be developed and implemented well by policy makers who intend to solve this issue. In this paper, Quanzhou Bay in southeastern China was selected as a case study; and the Kriging method and a geographic information system were employed to evaluate and optimize the existing monitoring network in a semienclosed bay. This study used coastal environmental monitoring data from 15 sites (including COD, DIN, and PO4-P) to adequately analyze the water quality from 2009 to 2012 by applying the Trophic State Index. The monitoring network in Quanzhou Bay was evaluated and optimized, with the number of sites increased from 15 to 24, and the monitoring precision improved by 32.9%. The results demonstrated that the proposed advanced monitoring network optimization was appropriate for environmental monitoring in Quanzhou Bay. It might provide technical support for coastal management and pollutant reduction in similar areas. PMID:27777951

Optimization of a Coastal Environmental Monitoring Network Based on the Kriging Method: A Case Study of Quanzhou Bay, China

Directory of Open Access Journals (Sweden)

Kai Chen

2016-01-01

Full Text Available Environmental monitoring is fundamental in assessing environmental quality and to fulfill protection and management measures with permit conditions. However, coastal environmental monitoring work faces many problems and challenges, including the fact that monitoring information cannot be linked up with evaluation, monitoring data cannot well reflect the current coastal environmental condition, and monitoring activities are limited by cost constraints. For these reasons, protection and management measures cannot be developed and implemented well by policy makers who intend to solve this issue. In this paper, Quanzhou Bay in southeastern China was selected as a case study; and the Kriging method and a geographic information system were employed to evaluate and optimize the existing monitoring network in a semienclosed bay. This study used coastal environmental monitoring data from 15 sites (including COD, DIN, and PO4-P to adequately analyze the water quality from 2009 to 2012 by applying the Trophic State Index. The monitoring network in Quanzhou Bay was evaluated and optimized, with the number of sites increased from 15 to 24, and the monitoring precision improved by 32.9%. The results demonstrated that the proposed advanced monitoring network optimization was appropriate for environmental monitoring in Quanzhou Bay. It might provide technical support for coastal management and pollutant reduction in similar areas.

Greenland coastal air temperatures linked to Baffin Bay and Greenland Sea ice conditions during autumn through regional blocking patterns

Science.gov (United States)

Ballinger, Thomas J.; Hanna, Edward; Hall, Richard J.; Miller, Jeffrey; Ribergaard, Mads H.; Høyer, Jacob L.

2018-01-01

Variations in sea ice freeze onset and regional sea surface temperatures (SSTs) in Baffin Bay and Greenland Sea are linked to autumn surface air temperatures (SATs) around coastal Greenland through 500 hPa blocking patterns, 1979-2014. We find strong, statistically significant correlations between Baffin Bay freeze onset and SSTs and SATs across the western and southernmost coastal areas, while weaker and fewer significant correlations are found between eastern SATs, SSTs, and freeze periods observed in the neighboring Greenland Sea. Autumn Greenland Blocking Index values and the incidence of meridional circulation patterns have increased over the modern sea ice monitoring era. Increased anticyclonic blocking patterns promote poleward transport of warm air from lower latitudes and local warm air advection onshore from ocean-atmosphere sensible heat exchange through ice-free or thin ice-covered seas bordering the coastal stations. Temperature composites by years of extreme late freeze conditions, occurring since 2006 in Baffin Bay, reveal positive monthly SAT departures that often exceed 1 standard deviation from the 1981-2010 climate normal over coastal areas that exhibit a similar spatial pattern as the peak correlations.

Transcriptome analysis deciphers evolutionary mechanisms underlying genetic differentiation between coastal and offshore anchovy populations in the Bay of Biscay

KAUST Repository

Montes, Iratxe; Zarraonaindia, Iratxe; Iriondo, Mikel; Grant, W. Stewart; Manzano, Carmen; Cotano, Unai; Conklin, Darrell; Irigoien, Xabier; Estonba, Andone

2016-01-01

Morphometry and otolith microchemistry point to the existence of two populations of the European anchovy (Engraulis encrasicolus) in the Bay of Biscay: one in open seawaters, and a yet unidentified population in coastal waters. To test this hypothesis, we assembled a large number of samples from the region, including 587 juveniles and spawning adults from offshore and coastal waters, and 264 fish from other locations covering most of the species’ European range. These samples were genotyped for 456 exonic SNPs that provide a robust way to decipher adaptive processes in these populations. Two genetically differentiated populations of anchovy inhabit the Bay of Biscay with different population dynamics: (1) a large offshore population associated with marine waters included in the wide-shelf group, and (2) a coastal metapopulation adapted to estuarine environments in the Bay of Biscay and North Sea included in the narrow-shelf group. Transcriptome analysis identified neutral and adaptive evolutionary processes underlying differentiation between these populations. Reduced gene flow between offshore and coastal populations in the Bay of Biscay appears to result from divergence between two previously isolated gene pools adapted to contrasting habitats and now in secondary contact. Eleven molecular markers appear to mark divergent selection between the ecotypes, and a majority of these markers are associated with salinity variability. Ecotype differences at two outlier genes, TSSK6 and basigin, may hinder gamete compatibility between the ecotypes and reinforce reproductive isolation. Additionally, possible convergent evolution between offshore and coastal populations in the Bay of Biscay has been detected for the syntaxin1B-otoferlin gene system, which is involved in the control of larval buoyancy. Further study of exonic markers opens the possibility of understanding the mechanisms of adaptive divergence between European anchovy populations. © 2016, Springer

Transcriptome analysis deciphers evolutionary mechanisms underlying genetic differentiation between coastal and offshore anchovy populations in the Bay of Biscay

KAUST Repository

Montes, Iratxe

2016-09-13

Morphometry and otolith microchemistry point to the existence of two populations of the European anchovy (Engraulis encrasicolus) in the Bay of Biscay: one in open seawaters, and a yet unidentified population in coastal waters. To test this hypothesis, we assembled a large number of samples from the region, including 587 juveniles and spawning adults from offshore and coastal waters, and 264 fish from other locations covering most of the species’ European range. These samples were genotyped for 456 exonic SNPs that provide a robust way to decipher adaptive processes in these populations. Two genetically differentiated populations of anchovy inhabit the Bay of Biscay with different population dynamics: (1) a large offshore population associated with marine waters included in the wide-shelf group, and (2) a coastal metapopulation adapted to estuarine environments in the Bay of Biscay and North Sea included in the narrow-shelf group. Transcriptome analysis identified neutral and adaptive evolutionary processes underlying differentiation between these populations. Reduced gene flow between offshore and coastal populations in the Bay of Biscay appears to result from divergence between two previously isolated gene pools adapted to contrasting habitats and now in secondary contact. Eleven molecular markers appear to mark divergent selection between the ecotypes, and a majority of these markers are associated with salinity variability. Ecotype differences at two outlier genes, TSSK6 and basigin, may hinder gamete compatibility between the ecotypes and reinforce reproductive isolation. Additionally, possible convergent evolution between offshore and coastal populations in the Bay of Biscay has been detected for the syntaxin1B-otoferlin gene system, which is involved in the control of larval buoyancy. Further study of exonic markers opens the possibility of understanding the mechanisms of adaptive divergence between European anchovy populations. © 2016, Springer

Impact of geographical factors on Coastal Tourism between İğneada and Kastro Bay, Thracian Black Sea coast, Turkey

Directory of Open Access Journals (Sweden)

Gülsen Erginal

2017-11-01

Full Text Available This study discusses the relationship between tourism and geomorphologic features, climatic comfort and natural vegetation cover in the coastal region from İğneada to Kastro Bay on the Black Sea. From the point of view of climatic comfort, Thermo-Hygrometric Index (THI values indicate that May, June, September and October are favorable for coastal tourism while in the months of July and August temperatures are too hot. SSI index values indicate that comfort levels prevail for most people in June and September although the weather can be perceived by some people as cool. In July and August, when the temperatures are higher, the climate is comfortable part of the time, but it is rather hot and sticky. Despite climatic comfort conditions not being suitable for long-duration coastal tourism in the Kıyıköy-İğneada area, the floristic richness of the area and presence of longose forests offer many opportunities in terms of ecotourism. There are also numerous lakes and streams presenting unique possibilities for a variety of so-far unexploited tourism activities. Geomorphologically, uncontaminated sandy beaches and coastal spits as well as sheltered bays such as Kastro Bay are among the important assets of the area in terms of coastal tourism.

Occurrence and distribution of antibiotics in coastal water of the Bohai Bay, China: Impacts of river discharge and aquaculture activities

International Nuclear Information System (INIS)

Zou Shichun; Xu Weihai; Zhang Ruijie; Tang Jianhui; Chen Yingjun; Zhang Gan

2011-01-01

The presence of 21 antibiotics in six different groups was investigated in coastal water of the Bohai Bay. Meantime, to illuminate the potential effects caused by the river discharge and aquaculture activities, wastewater from three breeding plants and surface water from six rivers flowing into the Bohai Bay were also analyzed for the selected antibiotics. The result revealed that measured antibiotics in the North Bobai Bay were generally higher than those in the South, highlighting the remarkable effects of high density of human activities on the exposure of antibiotics in environment. The antibiotics found in the six rivers were generally higher than those in the Bohai Bay reflecting the important antibiotics source of river discharge. This study reveals that the high consumption of some antibiotics in aquaculture activities may pose high ecological risk to the bay. - Highlights: → Some antibiotics were ubiquitous with high concentration in the Bohai bay, North China. → The antibiotics were mainly from the six rivers discharge around the Bay. → Antibiotics are commonly used in aquaculture activities around the Bay. → Aquaculture was suggested to be an important antibiotics source in the Bay. - River discharge and aquaculture were suggested to be important sources for antibiotics occurred in the coastal water of the Bohai Bay, North China.

Numerical Simulation of Salinity and Dissolved Oxygen at Perdido Bay and Adjacent Coastal Ocean

Science.gov (United States)

Environmental Fluid Dynamic Code (EFDC), a numerical estuarine and coastal ocean circulation hydrodynamic model, was used to simulate the distribution of the salinity, temperature, nutrients and dissolved oxygen (DO) in Perdido Bay and adjacent Gulf of Mexico. External forcing fa...

Enhanced abundance of tintinnids under elevated CO2 level from coastal Bay of Bengal

Digital Repository Service at National Institute of Oceanography (India)

Biswas, H.; Gadi, S.D.; Venkataramana, V.; Bharathi, M.D.; Priyan, R.K.; Manjari, D.T.; DileepKumar, M.

of marine plankton to increasing CO2 concentrations. Natural water samples from the coastal Bay of Bengal were incubated under the ambient condition and high CO2 levels (703-711 latm) for 5 days in May and June 2010. A significant negative correlation...

Evaluation of coastal waters receiving fish processing waste: Lota Bay as a case study.

Science.gov (United States)

Ahumada, Ramón; Rudolph, Anny; Contreras, Sergio

2004-01-01

Liquid wastes from the fish meal and oil processing industries produce serious environmental impacts in coastal embayments on the coasts of Chile and Peru. This article presents an analysis of an environmental monitoring program at Lota Bay, a shallow coastal indentation in central Chile (37 degrees S) exposed to industrial fishing activity. The study of the environmental impact produced by waste effluents permitted making an evaluation of the bay's capacity for seasonal recovery from this impact. Seasonal cruises were carried out during 1994 and in 1996, 1997, and 1998. Variables analyzed included salinity, temperature, dissolved oxygen, ammonium concentration and surface oil and grease. The hydrographic regime of Lota Bay follows a seasonal pattern, where, typical of most SE pacific embayments, waters from subsuperficial oxygen minimum zones moved into the bay. The percentages of dissolved oxygen were critical in the area of organic waste discharge. The impact of wastewater is related to the type and status of the fishery, including: (i) overloads of plant production lines, (ii) maintenance and cleaning of installations, and (iii) degree of shipboard fishing conservation. Major alterations were observed in summer, when the highest discharge of organic load occurred. In winter, an improvement in the re-aeration conditions reduced the impact. Remedial measures implemented beginning in 1997 arose from the monitoring program and had to be separated into two recovery factors including (a) internal management of plants and (b) treatment of plant effluents.

Issues in ecology: Nutrient pollution of coastal rivers, bays, and seas

Science.gov (United States)

Howarth, Robert W.; Anderson, D. B.; Cloern, James E.; Elfring, Chris; Hopkinson, Charles S.; Lapointe, Brian; Maloney, Thomas J.; Marcus, Nancy; McGlathery, Karen; Sharpley, A.N.; Walker, D.

2000-01-01

Over the past 40 years, antipollution laws have greatly reduced discharges of toxic substances into our coastal waters. This effort, however, has focused largely on point-source pollution of industrial and municipal effluent. No comparable effort has been made to restrict the input of nitrogen (N) from municipal effluent, nor to control the flows of N and phosphorus (P) that enter waterways from dispersed or nonpoint sources such as agricultural and urban runoff or as airborne pollutants. As a result, inputs of nonpoint pollutants, particularly N, have increased dramatically. Nonpoint pollution from N and P now represents the largest pollution problem facing the vital coastal waters of the United States. Nutrient pollution is the common thread that links an array of problems along the nation’s coastline, including eutrophication, harmful algal blooms, ”dead zones,” fish kills, some shellfish poisonings, loss of seagrass and kelp beds, some coral reef destruction, and even some marine mammal and seabird deaths. More than 60 percent of our coastal rivers and bays in every coastal state of the continental United States are moderately to severely degraded by nutrient pollution. This degradation is particularly severe in the mid Atlantic states, in the southeast, and in the Gulf of Mexico. A recent report from the National Research Council entitled “Clean Coastal Waters: Understanding and Reduc- ing the Effects of Nutrient Pollution” concludes that: Nutrient over-enrichment of coastal ecosystems generally triggers ecological changes that decrease the biologi- cal diversity of bays and estuaries. While moderate N enrichment of some coastal waters may increase fish production, over-enrichment generally degrades the marine food web that supports commercially valuable fish. The marked increase in nutrient pollution of coastal waters has been accompanied by an increase in harmful algal blooms, and in at least some cases, pollution has triggered these blooms. High

THE IMPLEMENTATION OF LILIFUK CUSTOMARY LAW TOWARDS COASTAL ENVIRONMENTAL DEGRADATION OF KUPANG BAY

Directory of Open Access Journals (Sweden)

Ranny Christine Unbanunaek

2017-02-01

Full Text Available The kuanheun coastal communities have a customary law that help maintain coastal environmental sustainability resourceS called as lilifuk customary law(lilifuk atolan instrument. This research applied empirical method by formulating three problems: what are the values embedded in lilifuk customary law; how is the of lilifuk customary law contribution to prevent coastal environmental degradation; and how is the correlation between lilifuk customary law values and the law provision on coastal areas and small islands management. The result of the research identified the following; the first, Lilifuk customary law contains religious value, ecological value, communal value, social relations value, solidarity and responsibility value, social leadership value, and educational value. Second, the settlement of law violation by lilifuk customary law is conduted by the following steps: reporting; discussion; verdict; and  execution. Third, there is a correlation between the lilifuk customary lilifuk values and  WP3K Law values. Keywords: lilifuk customary law, environmental degradation, kupang bay

Geochemistry of organic carbon and nitrogen in surface sediments of coastal Bohai Bay inferred from their ratios and stable isotopic signatures

International Nuclear Information System (INIS)

Gao Xuelu; Yang Yuwei; Wang Chuanyuan

2012-01-01

Total organic carbon (TOC), total nitrogen (TN) and their δ 13 C and δ 15 N values were determined for 42 surface sediments from coastal Bohai Bay in order to determine the concentration and identify the source of organic matter. The sampling sites covered both the marine region of coastal Bohai Bay and the major rivers it connects with. More abundant TOC and TN in sediments from rivers than from the marine region reflect the situation that most of the terrestrial organic matter is deposited before it meets the sea. The spatial variation in δ 13 C and δ 15 N signatures implies that the input of organic matter from anthropogenic activities has a more significant influence on its distribution than that from natural processes. Taking the area as a whole, surface sediments in the marine region of coastal Bohai Bay are dominated by marine derived organic carbon, which on average accounts for 62 ± 11% of TOC.

Anthropogenic influences on shoreline and nearshore evolution in the San Francisco Bay coastal system

Science.gov (United States)

Dallas, K.L.; Barnard, P.L.

2011-01-01

Analysis of four historical bathymetric surveys over a 132-year period has revealed significant changes to the morphology of the San Francisco Bar, an ebb-tidal delta at the mouth of San Francisco Bay estuary. From 1873 to 2005 the San Francisco Bar vertically-eroded an average of 80 cm over a 125 km2 area, which equates to a total volume loss of 100 ± 52 million m3 of fine- to coarse-grained sand. Comparison of the surveys indicates the entire ebb-tidal delta contracted radially, with the crest moving landward an average of 1 km. Long-term erosion of the ebb-tidal delta is hypothesized to be due to a reduction in the tidal prism of San Francisco Bay and a decrease in coastal sediment supply, both as a result of anthropogenic activities. Prior research indicates that the tidal prism of the estuary was reduced by 9% from filling, diking, and sedimentation. Compilation of historical records dating back to 1900 reveals that a minimum of 200 million m3 of sediment has been permanently removed from the San Francisco Bay coastal system through dredging, aggregate mining, and borrow pit mining. Of this total, ~54 million m3 of sand-sized or coarser sediment was removed from central San Francisco Bay. With grain sizes comparable to the ebb-tidal delta, and its direct connection to the bay mouth, removal of sediments from central San Francisco Bay may limit the sand supply to the delta and open coast beaches. SWAN wave modeling illustrates that changes to the morphology of the San Francisco Bar have altered the alongshore wave energy distribution at adjacent Ocean Beach, and thus may be a significant factor in a persistent beach erosion ‘hot spot’ occurring in the area. Shoreline change analyses show that the sandy shoreline in the shadow of the ebb-tidal delta experienced long-term (1850s/1890s to 2002) and short-term (1960s/1980s to 2002) accretion while the adjacent sandy shoreline exposed to open-ocean waves experienced long-term and short-term erosion. Therefore

Evaluation and analysis of underground brine resources in the southern coastal area of Laizhou Bay

Science.gov (United States)

Tian, M.; Zhu, H. T.; Feng, J.; Zhao, Q. S.

2016-08-01

The southern coastal districts of Laizhou Bay are some of the most important areas for underground brine exploitation in Shandong Province. Recently, these areas have been gradually developed by the underground brine mining industry. Such economic interest has led to brine exploitation so that underground brine resources are running out. Based on this phenomenon, this study describes the supply, runoff and draining conditions of the area by collecting and organizing the background information of the studied area. Hydrogeological parameters are then calculated according to pumping tests, and the amount of sustainable resources in the coastal areas of the Southern Bank of Laizhou Bay are then calculated based on the uniform distribution of wells. Under the circumstances of underground brine mining, the exploitation potential of the underground brine is evaluated in accordance with the calculation results of exploitation quantum. Finally, suggestions are provided for the sustainable exploitation of underground brine in the area.

Results of complex annual parasitological monitoring in the coastal area of Kola Bay

Science.gov (United States)

Kuklin, V. V.; Kuklina, M. M.; Kisova, N. E.; Maslich, M. A.

2009-12-01

The results of annual parasitological monitoring in the coastal area near the Abram-mys (Kola Bay, Barents Sea) are presented. The studies were performed in 2006-2007 and included complex examination of the intermediate hosts (mollusks and crustaceans) and definitive hosts (marine fish and birds) of the helminths. The biodiversity of the parasite fauna, seasonal dynamics, and functioning patterns of the parasite systems were investigated. The basic regularities in parasite circulation were assessed in relation to their life cycle strategies and the ecological features of the intermediate and definitive hosts. The factors affecting the success of parasite circulation in the coastal ecosystems were revealed through analysis of parasite biodiversity and abundance dynamics.

The Lower Chesapeake Bay LTAR: A coastal urban-agricultural region

Science.gov (United States)

Mccarty, G.; Alfieri, J. G.; Cavigelli, M.; Cosh, M. H.; Hapeman, C. J.; Kustas, W. P.; Maul, J.; Mirsky, S.; Pooler, M.; Sadeghi, A. M.; Schomberg, H.; Timlin, D. J.; Rice, C. P.

2015-12-01

The Chesapeake Bay, located in the mid-Atlantic region of the U.S., is the largest estuary in North America. The watershed area includes six states from New York to Virginia and is nearly 167,000 km2 in size with more than 150 rivers and streams entering the 300-km Bay main stem. Forested and agricultural lands make up 58 and 22 percent of the land use, respectively. Nearly 9 percent is urban and suburban use, and the watershed is home to over 17 million people. However, the population is expected to reach 19 million by 2025, raising the potential for conflict between the agricultural and urban communities over land and water use and in protecting natural resources, especially in the lower portion of the Chesapeake Bay watershed. The Lower Chesapeake Bay study area, part of the USDA-ARS Long-Term Agroecosystem Research (LTAR) network, will provide much-needed data to support decisions at this critical agriculture-urban interface. Current long-term projects seek to assess the economic, production, and environmental performance of conventional and organic cropping systems and to evaluate the resilience of these systems to climate change. Large-scale studies are being conducted to examine the effects of land-use and landscape characteristics on ecosystem services and on energy, water, nutrient, carbon, and pest dynamics within watersheds. New in-situ measurement and remote sensor technologies are being considered with the expectancy that the data streams will be available on-line and for use in modeling. Results and outcomes of these research efforts will greatly benefit the national LTAR network and will be applicable to other US coastal urban-agricultural regions.

Connectivity of a large embayment and coastal fishery: spawning aggregations in one bay source local and broad-scale fishery replenishment.

Science.gov (United States)

Hamer, P A; Acevedo, S; Jenkins, G P; Newman, A

2011-04-01

Ichthyoplankton sampling and otolith chemistry were used to determine the importance of transient spawning aggregations of snapper Chrysophrys auratus (Sparidae) in a large embayment, Port Phillip Bay (PPB), Australia, as a source of local and broad-scale fishery replenishment. Ichthyoplankton sampling across five spawning seasons within PPB, across the narrow entrance to the bay and in adjacent coastal waters, indicated that although spawning may occur in coastal waters, the spawning aggregations within the bay were the primary source of larval recruitment to the bay. Otolith chemical signatures previously characterized for 0+ year C. auratus of two cohorts (2000 and 2001) were used as the baseline signatures to quantify the contribution that fish derived from reproduction in PPB make to fishery replenishment. Sampling of these cohorts over a 5 year period at various widely dispersed fishery regions, combined with maximum likelihood analyses of the chemistry of the 0+ year otolith portions of these older fish, indicated that C. auratus of 1 to 3+ years of age displayed both local residency and broad-scale emigration from PPB to populate coastal waters and an adjacent bay (Western Port). While the PPB fishery was consistently dominated (>70%) by locally derived fish irrespective of cohort or age, the contribution of fish that had originated from PPB to distant populations increased with age. At 4 to 5+ years of age, when C. auratus mature and fully recruit to the fishery, populations of both cohorts across the entire central and western Victorian fishery, including two major embayments and c. 800 km of coastal waters, were dominated (>70%) by fish that had originated from the spawning aggregations and nursery habitat within PPB. Dependence of this broadly dispersed fishery on replenishment from heavily targeted spawning aggregations within one embayment has significant implications for management and monitoring programmes. © 2011 The Authors. Journal of Fish

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.

Coastal Acidification as Nutrients Over Enrichment Impact: A Case Study in Ambon Bay, Indonesia

Directory of Open Access Journals (Sweden)

Idha Yulia Ikhsani

2017-05-01

Full Text Available Ambon Bay is a silled bay on Ambon Island consisting of two regions, Inner Ambon Bay (IAB and Outer Ambon Bay (OAB that are separated by shallow sill. Ambon bay and its surrounding have economically important ecosystem since the utilization for many activities. The bay is affected by anthropogenic impacts associated with urbanization, climate change, and nutrients over enrichment. The “deep water-rich nutrients” from Banda Sea that enter the bay during Southeast monsoon also contribute to this enrichment as well as the nutrients transport from the land. The high concentration of nutrients increases carbon dioxide level and promotes acidifications. There are literatures about nutrients over enrichment in Ambon Bay, however, little is known about coastal acidification as nutrients over enrichment impact. In order to study the effect of nutrients distribution on the acidity of Ambon Bay, the researchers measured pH and concentrations of nutrients {nitrate + nitrite (N+N and Soluble Reactive Phosphate (SRP} from water samples collected in 7 stations on both IAB and OAB during Southeast monsoon. The results showed that in surface water, nutrients concentrations is increased from May to June due to the “deep water flushing” occurrence on May and increased precipitations from May to June. From July to August, the nutrients concentrations on surface layer decreased, due to the decreased precipitations. In column and bottom water, the nutrients concentrations were increased from May to August. While the acidity have reverse pattern from the nutrients, when nutrient concentrations increased the acidity was decreased. From correlation test, pH was not significantly correlated with the concentrations of nutrients on surface water, but showed significantly correlated on column and bottom water. The results indicated that the distribution of nutrients on column and bottom water might be an important environmental factor affecting the acidification of

Changes of hydrological environment and their influences on coastal wetlands in the southern Laizhou Bay, China.

Science.gov (United States)

Zhang, Xuliang; Zhang, Yuanzhi; Sun, Hongxia; Xia, Dongxing

2006-08-01

The structure and function of the coastal wetland ecosystem in the southern Laizhou Bay have been changed greatly and influenced by regional hydrological changes. The coastal wetlands have degraded significantly during the latest 30 years due to successive drought, decreasing of runoff, pollution, underground saline water intrusion, and aggravating marine disasters such as storm tides and sea level rising. Most archaic lakes have vanished, while artificial wetlands have been extending since natural coastal wetlands replaced by salt areas and ponds of shrimps and crabs. The pollution of sediments in inter-tidal wetlands and the pollution of water quality in sub-tidal wetlands are getting worse and therefore "red tides" happen more often than before. The biodiversity in the study area has been decreased. Further studies are still needed to protect the degraded coastal wetlands in the area.

NOAA Office for Coastal Management RoxAnn Acoustic Sensor Benthic Habitat Data, Rehoboth Bay, Delaware, 2000 (NODC Accession 0089461)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — During the spring of 1999, the Delaware Coastal Programs (DCP) identified the spatial extent of macroalgae in the shallow portions of Rehoboth Bay utilizing...

Observed changes in ocean acidity and carbon dioxide exchange in the coastal Bay of Bengal - a link to air pollution

Digital Repository Service at National Institute of Oceanography (India)

Sarma, V.V.S.S.; Krishna, M.S.; Paul, Y.S.; Murty, V.S.N.

acidity and carbon dioxide exchange in the coastal Bay of Bengal � a link to air pollution By V. V. S. S. SARMA*, M. S. KRISHNA, Y. S. PAUL and V. S. N. MURTY, CSIR�National Institute of Oceanography, 176 Lawsons Bay Colony, Visakhapatnam, India... atmosphere boundary layer over the Bay of Bengal (mean: 5.7 mg m�3) compared to fluxes in the Arabian Sea (mean: 2.9 mg m�3), indicating that the former receives more pollutants than the latter region during January to April when air flow from land to sea...

Landscape pattern evolution of the north of Hangzhou bay coastal area in Shanghai

Directory of Open Access Journals (Sweden)

LIANG Shuai

2012-12-01

Full Text Available Since the 1980s in Shanghai,fast economic development,rapid urbanization,population explosion,all of these phenomena are driving radical changes in landscape pattern of coastal area.The landscape pattern evolution at the coastal regions of the north of the Hangzhou bay is analysed based on the landscape ecology theory and method by using Fragstats 3.3 software.3S technology is utilized to interpretate the sensing images at three phase in 1994,2003,2007,and selected two landscape index of the landscape level to study six town from time and space on the contrast analysis.The results show that farmland landscape is the dominant landscape in research area,landscape diversity is high and shows ascendant trend;For 13 years,six towns’(street fragmentation degree increase,the Luchaogang town has the highest degree of fragmentation.

Prevalence of Vibrio vulnificus and Vibrio parahaemolyticus in the Maryland Coastal Bays

Science.gov (United States)

De Pascuale, V. O.

2016-02-01

The bacterial family of Vibrionaceae is indigenous in the marine estuarine environments such as the Maryland Coastal Bays. Vibrio vulnificus and Vibrio parahaemolyticus are both pathogenic bacteria. Understanding the distribution of Vibrio species is crucial because of the health concerns associated with the bacteria. The aim of this study was to evaluate the overall abundance of bacteria with a focus on Vibrio species in the Maryland Coastal Bays. Seawater samples were collected from 10 different sites that differ with regard to water quality. The total bacteria count (TBC) was determined by two methods: Total plate count and Epifluorescence microscopy. The most-probable-number (MPN) methodology was used to estimate the population of Vibrio parahaemolyticus and Vibrio vulnificus. In addition to the bacteriological analysis, the environmental parameters of temperature and salinity were measured using YSI 6600 multiparameter meter. The average total bacteria count was 2.21 log CFU ml-1. Vibrio vulnificus comprised 5% of the total bacteria count while Vibrio parahaemolyticus comprised only 2% of the total bacteria count. Vibrio vulnificus ranged from 0.30 to 2.48 log MPN ml-1 at the sites tested. Lower Vibrio parahaemolyticus count was observed at the sites with a range of 0.30 to 1.97 log MPN ml-1. There was no significant correlation between the environmental parameters and the Vibrio spp. Since both Vibrio vulnificus and Vibrio parahaemolyticus peak in the summer, there is a potential for a risk of wound infections and gastrointestinal illness based on this data.

Predicting seasonal variations in coastal seabird habitats in the English Channel and the Bay of Biscay

Science.gov (United States)

Virgili, A.; Lambert, C.; Pettex, E.; Dorémus, G.; Van Canneyt, O.; Ridoux, V.

2017-07-01

Seabirds, like all animals, have to live in suitable habitats to fulfil their energetic needs for both somatic and reproductive growth and maintenance. Apart from migration trips, all coastal seabirds are linked to the coast, because they need to return daily to land for resting or breeding. Their use of marine habitats strongly depends on their biology, but also on environmental conditions, and can be described using habitat models. This study aimed to: (1) identify the processes that mostly influence seabird distributions along the coasts of the English Channel and the Bay of Biscay; (2) determine seasonal variations of these processes, (3) provide prediction maps that describe the species distributions. We collected data of coastal seabird sightings from aerial surveys carried out in the English Channel and the eastern North Atlantic in the winter 2011-2012 and summer 2012. We classified seabirds into morphological groups and described their habitats using physiographic and oceanographic variables in Generalised Additive Models (GAMs). Finally, we produced maps of predicted distributions by season for each group. The distributions of coastal seabirds were essentially determined by the distance to the nearest coast, with a weaker influence of oceanographic variables. The nature of the substrate, sand or rock, combined with the timing of reproduction, also contributed to determine seasonal at-sea distributions for some species. The highest densities were predicted near the coast, particularly in bays and estuaries for strictly coastal species with possible variations depending on the season. From this study, we were able to predict the seasonal distribution of the studied species according to varying environmental parameters that changed over time, allowing us to understand better their behaviour and ecology.

Identification of spatiotemporal nutrient patterns in a coastal bay via an integrated k-means clustering and gravity model.

Science.gov (United States)

Chang, Ni-Bin; Wimberly, Brent; Xuan, Zhemin

2012-03-01

This study presents an integrated k-means clustering and gravity model (IKCGM) for investigating the spatiotemporal patterns of nutrient and associated dissolved oxygen levels in Tampa Bay, Florida. By using a k-means clustering analysis to first partition the nutrient data into a user-specified number of subsets, it is possible to discover the spatiotemporal patterns of nutrient distribution in the bay and capture the inherent linkages of hydrodynamic and biogeochemical features. Such patterns may then be combined with a gravity model to link the nutrient source contribution from each coastal watershed to the generated clusters in the bay to aid in the source proportion analysis for environmental management. The clustering analysis was carried out based on 1 year (2008) water quality data composed of 55 sample stations throughout Tampa Bay collected by the Environmental Protection Commission of Hillsborough County. In addition, hydrological and river water quality data of the same year were acquired from the United States Geological Survey's National Water Information System to support the gravity modeling analysis. The results show that the k-means model with 8 clusters is the optimal choice, in which cluster 2 at Lower Tampa Bay had the minimum values of total nitrogen (TN) concentrations, chlorophyll a (Chl-a) concentrations, and ocean color values in every season as well as the minimum concentration of total phosphorus (TP) in three consecutive seasons in 2008. The datasets indicate that Lower Tampa Bay is an area with limited nutrient input throughout the year. Cluster 5, located in Middle Tampa Bay, displayed elevated TN concentrations, ocean color values, and Chl-a concentrations, suggesting that high values of colored dissolved organic matter are linked with some nutrient sources. The data presented by the gravity modeling analysis indicate that the Alafia River Basin is the major contributor of nutrients in terms of both TP and TN values in all seasons

Neural network modelling of planform geometry of headland-bay beaches

Science.gov (United States)

Iglesias, G.; López, I.; Castro, A.; Carballo, R.

2009-02-01

The shoreline of beaches in the lee of coastal salients or man-made structures, usually known as headland-bay beaches, has a distinctive curvature; wave fronts curve as a result of wave diffraction at the headland and in turn cause the shoreline to bend. The ensuing curved planform is of great interest both as a peculiar landform and in the context of engineering projects in which it is necessary to predict how a coastal structure will affect the sandy shoreline in its lee. A number of empirical models have been put forward, each based on a specific equation. A novel approach, based on the application of artificial neural networks, is presented in this work. Unlike the conventional method, no particular equation of the planform is embedded in the model. Instead, it is the model itself that learns about the problem from a series of examples of headland-bay beaches (the training set) and thereafter applies this self-acquired knowledge to other cases (the test set) for validation. Twenty-three headland-bay beaches from around the world were selected, of which sixteen and seven make up the training and test sets, respectively. As there is no well-developed theory for deciding upon the most convenient neural network architecture to deal with a particular data set, an experimental study was conducted in which ten different architectures with one and two hidden neuron layers and five training algorithms - 50 different options combining network architecture and training algorithm - were compared. Each of these options was implemented, trained and tested in order to find the best-performing approach for modelling the planform of headland-bay beaches. Finally, the selected neural network model was compared with a state-of-the-art planform model and was shown to outperform it.

Distribution and behavior of major and trace elements in Tokyo Bay, Mutsu Bay and Funka Bay marine sediments

International Nuclear Information System (INIS)

Honda, Teruyuki; Kimura, Ken-ichiro

2003-01-01

Fourteen major and trace elements in marine sediment core samples collected from the coasts along eastern Japan, i.e. Tokyo Bay (II) (the recess), Tokyo Bay (IV) (the mouth), Mutsu Bay and Funka Bay and the Northwest Pacific basin as a comparative subject were determined by the instrumental neutron activation analysis (INAA). The sedimentation rates and sedimentary ages were calculated for the coastal sediment cores by the 210 Pb method. The results obtained in this study are summarized as follows: (1) Lanthanoid abundance patterns suggested that the major origin of the sediments was terrigenous material. La*/Lu* and Ce*/La* ratios revealed that the sediments from Tokyo Bay (II) and Mutsu Bay more directly reflected the contribution from river than those of other regions. In addition, the Th/Sc ratio indicated that the coastal sediments mainly originated in the materials from the volcanic island-arcs, Japanese islands, whereas those from the Northwest Pacific mainly from the continent. (2) The correlation between the Ce/U and Th/U ratios with high correlation coefficients of 0.920 to 0.991 indicated that all the sediments from Tokyo Bay (II) and Funka Bay were in reducing conditions while at least the upper sediments from Tokyo Bay (IV) and Mutsu Bay were in oxidizing conditions. (3) It became quite obvious that the sedimentation mechanism and the sedimentation environment at Tokyo Bay (II) was different from those at Tokyo Bay (IV), since the sedimentation rate at Tokyo Bay (II) was approximately twice as large as that at Tokyo Bay (IV). The sedimentary age of the 5th layer (8∼10 cm in depth) from Funka Bay was calculated at approximately 1940∼50, which agreed with the time, 1943∼45 when Showa-shinzan was formed by the eruption of the Usu volcano. (author)

Modern sedimentation processes in a wave-dominated coastal embayment: Espírito Santo Bay, southeast Brazil

Science.gov (United States)

Bastos, Alex Cardoso; Costa Moscon, Daphnne Moraes; Carmo, Dannilo; Neto, José Antonio Baptista; da Silva Quaresma, Valéria

2015-02-01

Sediment dynamics in wave-dominated coastal embayments are generally controlled by seasonal meteorological conditions, storms having a particularly strong influence. In the present study, such hydrodynamic processes and associated deposits have been investigated in a coastal embayment located along the southeast coast of Brazil, i.e. Espírito Santo Bay, in the winter (June/July) of 2008. The bay has undergone a series of human interventions that have altered the local hydrodynamic processes and, consequently, the sediment transport patterns. Facies distribution and sediment dynamics were examined by acoustic seabed mapping, sediment and core sampling, hydrodynamic measurements and sand transport modelling. The results show that sediment distribution can be described in terms of nearshore and offshore zones. The offshore bay sector is predominantly composed of "palimpsest" lithoclastic medium-coarse sands deposited in the course of the early Holocene transgression that peaked about 5,000 years ago. In the inner bay or nearshore zone (up to depths of 4-8 m), these older transgressive deposits are today overlain by a thin (up to 30-cm-thick) and partly patchy blanket of younger regressive fine sand/muddy fine sands. Both coarse- and fine-grained facies are being reworked during high-energy events (Hs>1.5 m) when fine sediment is resuspended, weak tide-induced drift currents causing the sand patches to be displaced. The coarser sediment, by contrast, is mobilized as bedload to produce wave ripples with spacings of up to 1.2 m. These processes lead to a sharp spatial delimitation between a fine sand/mud facies and a rippled coarse sand facies. The fine sand patches have a relief of about 20-30 cm and reveal a typical internal tempestite depositional sequence. Fair-weather wave-induced sediment transport (Hs<1 m), supported by weak tidal currents, seems to only affect the fine sediment facies. Sediment dynamics in Espírito Santo Bay is thus essentially controlled by

Optical investigations of CDOM-rich coastal waters in Pärnu Bay

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Birgot Paavel

2011-06-01

Full Text Available Pärnu Bay in the Eastern Baltic Sea was chosen for studying the spatial-temporal variability of water parameters as an optically complex and semi-enclosed coastal area. The water properties of Pärnu Bay are influenced by the town of Pärnu with its 70 000 inhabitants and by the high inflow from the Pärnu River. The in situ database was collected during the ice-free period of 2006–2007 (11 sampling stations, 10 series of field trips. According to the results, the main factor influencing the light attenuation in the water was coloured dissolved organic matter (CDOM which overshadows the relationships between the radiation characteristics and organic/inorganic particles. In April and May, when the freshwater discharge of the Pärnu River was highest, the values of aCDOM(380 were between 4.6 and 31.8 m–1, while in September they varied only within 2.52–10.2 m–1. The concentrations of chlorophyll a (including its metabolite phaeophytin a generally ranged from 4 to 12 mg m–3 but during algal blooms they rapidly increased to 31.8 mg m–3. The temporal and spatial irregularity of suspended matter concentrations was caused by the loading of unpacked peat at the Pärnu River mouth as well as by undulation and ship traffic in Pärnu Bay. MODIS level 1 data with 250 m resolution were used for illustrative comparison of spatial and temporal variations in the water properties in Pärnu Bay and the Gulf of Riga. An attempt to perform the quantitative analysis with the purpose of estimating the concentrations of different optically significant substances separately gave statistically incorrect results.

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

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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. PMID:26207914

Distribution of trace elements in the coastal sea sediments of Maslinica Bay, Croatia

Science.gov (United States)

Mikulic, Nenad; Orescanin, Visnja; Elez, Loris; Pavicic, Ljiljana; Pezelj, Durdica; Lovrencic, Ivanka; Lulic, Stipe

2008-02-01

Spatial distributions of trace elements in the coastal sea sediments and water of Maslinica Bay (Southern Adriatic), Croatia and possible changes in marine flora and foraminifera communities due to pollution were investigated. Macro, micro and trace elements’ distributions in five granulometric fractions were determined for each sediment sample. Bulk sediment samples were also subjected to leaching tests. Elemental concentrations in sediments, sediment extracts and seawater were measured by source excited energy dispersive X-ray fluorescence (EDXRF). Concentrations of the elements Cr, Cu, Zn, and Pb in bulk sediment samples taken in the Maslinica Bay were from 2.1 to over six times enriched when compared with the background level determined for coarse grained carbonate sediments. A low degree of trace elements leaching determined for bulk sediments pointed to strong bonding of trace elements to sediment mineral phases. The analyses of marine flora pointed to higher eutrophication, which disturbs the balance between communities and natural habitats.

Occurrence and distribution of antibiotics in coastal water of the Bohai Bay, China: impacts of river discharge and aquaculture activities.

Science.gov (United States)

Zou, Shichun; Xu, Weihai; Zhang, Ruijie; Tang, Jianhui; Chen, Yingjun; Zhang, Gan

2011-10-01

The presence of 21 antibiotics in six different groups was investigated in coastal water of the Bohai Bay. Meantime, to illuminate the potential effects caused by the river discharge and aquaculture activities, wastewater from three breeding plants and surface water from six rivers flowing into the Bohai Bay were also analyzed for the selected antibiotics. The result revealed that measured antibiotics in the North Bobai Bay were generally higher than those in the South, highlighting the remarkable effects of high density of human activities on the exposure of antibiotics in environment. The antibiotics found in the six rivers were generally higher than those in the Bohai Bay reflecting the important antibiotics source of river discharge. This study reveals that the high consumption of some antibiotics in aquaculture activities may pose high ecological risk to the bay. Copyright © 2011 Elsevier Ltd. All rights reserved.

A Coastal Bay Summer Breeze Study, Part 1: Results of the Quiberon 2006 Experimental Campaign

Science.gov (United States)

Mestayer, Patrice G.; Calmet, Isabelle; Herlédant, Olivier; Barré, Sophie; Piquet, Thibaud; Rosant, Jean-Michel

2018-04-01

The Quiberon 2006 experiment was launched to document the onset and development of land and sea breezes over a semi-circular coastal bay propitious to inshore sailing competitions. The measurements were taken during the 2 weeks of 16-28 June 2006. Micrometeorological variables were recorded at three shore sites around the bay using turbulence sensors on 10-30-m high masts, on four instrumented catamarans at selected sites within the bay, and at a fourth shore site with a Sodar. Synoptic data and local measurements are analyzed here from the point of view of both micrometeorologists and competition skippers, testing in particular the empirical rules of breeze veering and backing according to the wind direction with respect to the coastline orientation at the mesoscale (the quadrant theory). Our analysis focuses on the patterns of lower-altitude wind direction and speed around the bay and over the water basin, and the temporal variations during the periods of the breeze onset, establishment and thermal reinforcement. In offshore synoptic-flow conditions (quadrants 1 and 2), the clockwise rotation of the surface flow had a very large amplitude, reaching up to 360°. The breeze strength was negatively correlated to that of the synoptic wind speed. In conditions of onshore synoptic flow from the west (quadrant 3) at an angle to the mainland coast but perpendicular to the Quiberon peninsula, the rotation of the flow was backwards in the early morning and clockwise during the day with a moderate amplitude (40°-50°) around the synoptic wind direction. As the surface wind speed was much larger than the synoptic wind speed, such a case we have designated as a "synoptic breeze". The breeze onset was shown to fail several times under the influence of weak non-thermal events, e.g., the passage of an occluded front or clouds or an excess of convection. Finally, several local-scale influences of the complex coastal shape appeared in our measurements, e.g., wind fanning in the

History as a guide to the future for cities: coastal storms and Jamaica Bay in New York City as an example.

Science.gov (United States)

Sanderson, E. W.; Orton, P. M.; Giampieri, M.; Spagnoli, C.

2015-12-01

History can provide a guide to the future by revealing the physical climatic and geomorphological dynamics with which cities must contend. We used historical maps from the U.S. Coast Survey and the Stevens Estuarine and Coastal Ocean Model (sECOM) to simulate how and where coastal flooding from storm surge affected the Jamaica Bay region of southeastern New York City at different points in time. This area, which houses approximately 1.2 million people today and the John F. Kennedy International Airport, was heavily impacted by coastal flooding during Hurricane Sandy. Historical analysis showed that the Rockaway Peninsula was an active barrier island system up until the early twentieth century, growing approximately 70 meters per year to the west between 1844 - 1891. Older historical maps made by American and European cartographers from 1524 - 1844 suggest that Jamaica Bay may have been a much more open system, with few or no interior marsh islands, at the time of European discovery. From these studies, we constructed digital terrain models and land cover maps for two historical periods: ca. 1870s and ca. 1609, and today. Storm simulations of hurricanes over the historical and present-day landscapes showed how a smaller inlet, shallower channel depths, and larger floodplains all can reduce the height of flooding inside the bay, and suggested a series of leverage experiments that test the efficacy of present-day green infrastructure interventions to lessen peak flood heights while maintaining tidal flushing. By combining history, modelling, and policy-relevant scenarios, we believe we have developed a reshreshing and accessible toolkit for policymakers thinking about resilience measures in coastal cities like New York.

Long time-series of turbid coastal water using AVHRR: an example from Florida Bay, USA

Science.gov (United States)

Stumpf, Richard P.; Frayer, M. L.

1997-02-01

The AVHRR can provide information on the reflectance of turbid case II water, permitting examination of large estuaries and plumes from major rivers. The AVHRR has been onboard several NOAA satellites, with afternoon overpasses since 1981, offering a long time-series to examine changes in coastal water. We are using AVHRR data starting in December 1989, to examine water clarity in Florida Bay, which has undergone a decline since the late 1980's. The processing involves obtaining a nominal reflectance for red light with standard corrections including those for Rayleigh and aerosol path radiances. Established relationships between reflectance and the water properties being measured in the Bay provide estimates of diffuse attenuation and light limitation for phytoplankton and seagrass productivity studies. Processing also includes monthly averages of reflectance and attenuation. The AVHRR data set describes spatial and temporal patterns, including resuspension of bottom sediments in the winter, and changes in water clarity. The AVHRR also indicates that Florida Bay has much higher reflectivity relative to attenuation than other southeastern US estuaries.

Corrosion of metals and alloys in the coastal and deep waters of the Arabian Sea and the Bay of Bengal

Digital Repository Service at National Institute of Oceanography (India)

Sawant, S.S.; Venkat, K.; Wagh, A.B.

Corrosion rate of mild steel (MS), stainless steel (SS), copper, brass and cupro-nickel has been determinEd. by exposing metallic coupons in coastal and oceanic waters of the Arabian Sea and Bay of Bengal. Amongst the metals and alloys under study...

Effects of Microbial and Heavy Metal Contaminants on Environmental/Ecological Health and Revitalization of Coastal Ecosystems in Delaware Bay

Directory of Open Access Journals (Sweden)

Gulnihal Ozbay

2017-06-01

Full Text Available The presence of heavy metals, excess nutrients, and microbial contaminants in aquatic systems of coastal Delaware has become a public concern as human population increases and land development continues. Delaware's coastal lagoons have been subjected to problems commonly shared by other coastal Mid-Atlantic states: turbidity, sedimentation, eutrophication, periodic hypoxic/anoxic conditions, toxic substances, and high bacterial levels. The cumulative impact of pollutants from run-off and point sources has degraded water quality, reduced the diversity and abundance of various fish species, invertebrates, and submerged aquatic vegetation. The effects are especially pronounced within the manmade dead end canal systems. In this article, we present selected case studies conducted in the Delaware Inland Bays. Due to the ecological services provided by bivalves, our studies in Delaware Inland Bays are geared toward oysters with special focus on the microbial loads followed by the water quality assessments of the bay. The relationships between oysters (Crassostrea virginica, microbial loads and nutrient levels in the water were investigated. The heavy metal levels monitored further away from the waste water treatment plant in the inland bays are marginally higher than the recommended EPA limits. Also, our studies confirmed that aerobic bacteria and Vibrionaceae levels are salinity dependent. Total bacteria in oysters increased when nitrate and total suspended solids increased in the waters. Studies such as these are important because every year millions of Americans consume raw oysters. Data collected over the last 10 years from our studies may be used to build a predictive index of conditions that are favorable for the proliferation of human pathogenic bacteria. Results from this study will benefit the local community by helping them understand the importance of oyster aquaculture and safe consumption of oysters while making them appreciate their

Oceanographic characteristics of an impacted coastal bay: Baía de Guanabara, Rio de Janeiro, Brazil

Science.gov (United States)

Kjerfve, Björn; Ribeiro, Cesar H. A.; Dias, Gilberto T. M.; Filippo, Alessandro M.; Da Silva Quaresma, Valéria

1997-11-01

Baía de Guanabara is a 384 km 2 eutrophic coastal bay in Brazil, impacted by the polluted discharge from the Rio de Janeiro metropolitan area. The structurally controlled bay has a central channel with a depth of 30 m and a sandy bottom near the entrance, reflecting wave and tidal forcing. In contrast, the bay-averaged water depth is 5.7 m and the bottom sediments are mostly muds as a result of the Holocene transgression and rapid fluvial sedimentation, accelerated by channelization of rivers and deforestation. An extensive sand bank is located seaward of the bay entrance and a flood-oriented sand wave system indicates sand transport into the bay. The mean freshwater discharge measures 100±59 m 3 s -1 and is greatest in the rainy austral summer in December and January. Tides are mixed mainly semidiurnal with a range of 0.7 m, and peak spring tidal currents reach 0.5 m s -1 inside the bay and 1.6 m s -1 near the bay entrance. The passage of northward propagating polar fronts results in regular strong southwesterly winds and heavy wave forcing. The bay has mean salinities from 21.0 to 34.5‰ with an average of 29.5±4.8‰. The vertical salinity stratification, Δs/s, varies from 0.06 to 0.21 and is relatively weak and inversely proportional to rms tidal currents. The residual circulation is characterized by both gravitational circulation and transverse residual tidal circulation, measuring 800 and 400 m 3 s -1 respectively. The renewal time of 50% of the bay water volume is 11.4 days. Untreated sewage runoff enters the bay from the west, resulting in locally poor water quality, where the near-bottom mean dissolved oxygen measures only 3.1 mg 1 -1 and results in anoxic bottom muds. The worst water quality is indicated by average fecal coliform of 1140 counts ml -1 and excessive ammonia and phosphate loading. The average chlorophyll concentration in this region responds to the nutrient loading and exceeds 130 μg 1 -1 although 57 μg 1 -1 is the overall mean for

Integration of bed characteristics, geochemical tracers, current measurements, and numerical modeling for assessing the provenance of beach sand in the San Francisco Bay Coastal System

Science.gov (United States)

Barnard, Patrick L.; Foxgrover, Amy C.; Elias, Edwin P.L.; Erikson, Li H.; Hein, James R.; McGann, Mary; Mizell, Kira; Rosenbauer, Robert J.; Swarzenski, Peter W.; Takesue, Renee K.; Wong, Florence L.; Woodrow, Donald L.; Barnard, P.L.; Jaffee, B.E.; Schoellhamer, D.H.

2013-01-01

Over 150 million m3 of sand-sized sediment has disappeared from the central region of the San Francisco Bay Coastal System during the last half century. This enormous loss may reflect numerous anthropogenic influences, such as watershed damming, bay-fill development, aggregate mining, and dredging. The reduction in Bay sediment also appears to be linked to a reduction in sediment supply and recent widespread erosion of adjacent beaches, wetlands, and submarine environments. A unique, multi-faceted provenance study was performed to definitively establish the primary sources, sinks, and transport pathways of beach-sized sand in the region, thereby identifying the activities and processes that directly limit supply to the outer coast. This integrative program is based on comprehensive surficial sediment sampling of the San Francisco Bay Coastal System, including the seabed, Bay floor, area beaches, adjacent rock units, and major drainages. Analyses of sample morphometrics and biological composition (e.g., Foraminifera) were then integrated with a suite of tracers including 87Sr/86Sr and 143Nd/144Nd isotopes, rare earth elements, semi-quantitative X-ray diffraction mineralogy, and heavy minerals, and with process-based numerical modeling, in situ current measurements, and bedform asymmetry to robustly determine the provenance of beach-sized sand in the region.

Coastal wetland adaptation to sea level rise: Quantifying potential for landward migration and coastal squeeze

Science.gov (United States)

Borchert, Sinéad M.; Osland, Michael J.; Enwright, Nicholas M.; Griffith, Kereen

2018-01-01

Coastal wetland ecosystems are expected to migrate landwards in response to rising seas. However, due to differences in topography and coastal urbanization, estuaries vary in their ability to accommodate migration. Low‐lying urban areas can constrain migration and lead to wetland loss (i.e. coastal squeeze), especially where existing wetlands cannot keep pace with rising seas via vertical adjustments. In many estuaries, there is a pressing need to identify landward migration corridors and better quantify the potential for landward migration and coastal squeeze.We quantified and compared the area available for landward migration of tidal saline wetlands and the area where urban development is expected to prevent migration for 39 estuaries along the wetland‐rich USA Gulf of Mexico coast. We did so under three sea level rise scenarios (0.5, 1.0, and 1.5 m by 2100).Within the region, the potential for wetland migration is highest within certain estuaries in Louisiana and southern Florida (e.g. Atchafalaya/Vermilion Bays, Mermentau River, Barataria Bay, and the North and South Ten Thousand Islands estuaries).The potential for coastal squeeze is highest in estuaries containing major metropolitan areas that extend into low‐lying lands. The Charlotte Harbor, Tampa Bay, and Crystal‐Pithlachascotee estuaries (Florida) have the highest amounts of urban land expected to constrain wetland migration. Urban barriers to migration are also high in the Galveston Bay (Texas) and Atchafalaya/Vermilion Bays (Louisiana) estuaries.Synthesis and applications. Coastal wetlands provide many ecosystem services that benefit human health and well‐being, including shoreline protection and fish and wildlife habitat. As the rate of sea level rise accelerates in response to climate change, coastal wetland resources could be lost in areas that lack space for landward migration. Migration corridors are particularly important in highly urbanized estuaries where, due to low‐lying coastal

Reconstruction of metal pollution and recent sedimentation processes in Havana Bay (Cuba): A tool for coastal ecosystem management

International Nuclear Information System (INIS)

Díaz-Asencio, M.; Alvarado, J.A. Corcho; Alonso-Hernández, C.; Quejido-Cabezas, A.; Ruiz-Fernández, A.C.; Sanchez-Sanchez, M.; Gómez-Mancebo, M.B.; Froidevaux, P.; Sanchez-Cabeza, J.A.

2011-01-01

Highlights: ► Past metal pollution in the heavy polluted coastal ecosystem of Havana Bay. ► Effectiveness of pollution-reduction strategies. ► Dated environmental archives to reconstruct sedimentation and pollution trends. ► Impact of severe climatic events on sedimentation. - Abstract: Since 1998 the highly polluted Havana Bay ecosystem has been the subject of a mitigation program. In order to determine whether pollution-reduction strategies were effective, we have evaluated the historical trends of pollution recorded in sediments of the Bay. A sediment core was dated radiometrically using natural and artificial fallout radionuclides. An irregularity in the 210 Pb record was caused by an episode of accelerated sedimentation. This episode was dated to occur in 1982, a year coincident with the heaviest rains reported in Havana over the XX century. Peaks of mass accumulation rates (MAR) were associated with hurricanes and intensive rains. In the past 60 years, these maxima are related to strong El Niño periods, which are known to increase rainfall in the north Caribbean region. We observed a steady increase of pollution (mainly Pb, Zn, Sn, and Hg) since the beginning of the century to the mid 90s, with enrichment factors as high as 6. MAR and pollution decreased rapidly after the mid 90s, although some trace metal levels remain high. This reduction was due to the integrated coastal zone management program introduced in the late 90s, which dismissed catchment erosion and pollution.

Changes in Landscape Pattern of Wetland around Hangzhou Bay

Science.gov (United States)

Lin, Wenpeng; Li, Yuan; Xu, Dan; Zeng, Ying

2018-04-01

Hangzhou Bay is an important estuarial coastal wetland, which offers a large number of land and ecological resources. It plays a significant role in the sustainable development of resources, environment and economy. In this paper, based on the remote sensing images in 1996, 2005 and 2013, we extracted the coastal wetland data and analyzed the wetland landscape pattern of the Hangzhou Bay in the past 20 years. The results show that: (1) the area of coastal wetland is heading downwards in the recent decades. Paddy field and the coastal wetland diminish greatly. (2) the single dynamic degree of wetland of the Hangzhou Bay displays that paddy fields and coastal wetlands are shrinking, but lakes, reservoirs and ponds are constantly expanding. (3) the wetland landscape pattern index shows that total patch area of the coastal wetland and paddy fields have gradually diminished. The Shannon diversity index, the Shannon evenness index as well as the landscape separation index of the coastal wetlands in the Hangzhou Bay increase steadily. The landscape pattern in the study area has shown a trend of high fragmentation, dominance decreases, but some dominant landscape still exist in this region. (4) Urbanization and natural factors lead to the reduction of wetland area. Besides the pressure of population is a major threat to the wetland. The study will provide scientific basis for long-term planning for this region.

A conceptual hydrologic model for a forested Carolina bay depressional wetland on the Coastal Plain of South Carolina, USA

Science.gov (United States)

Jennifer E. Pyzoha; Timothy J. Callahan; Ge Sun; Carl C. Trettin; Masato Miwa

2008-01-01

This paper describes how climate influences the hydrology of an ephemeral depressional wetland. Surface water and groundwater elevation data were collected for 7 years in a Coastal Plain watershed in South Carolina USA containing depressional wetlands, known as Carolina bays. Rainfall and temperature data were compared with water-table well and piezometer data in and...

Use of Land Use Land Cover Change Mapping Products in Aiding Coastal Habitat Conservation and Restoration Efforts of the Mobile Bay NEP

Science.gov (United States)

Spruce, Joseph P.; Swann, Roberta; Smooth, James

2010-01-01

The Mobile Bay region has undergone significant land use land cover change (LULC) over the last 35 years, much of which is associated with urbanization. These changes have impacted the region s water quality and wildlife habitat availability. In addition, much of the region is low-lying and close to the Gulf, which makes the region vulnerable to hurricanes, climate change (e.g., sea level rise), and sometimes man-made disasters such as the Deepwater Horizon (DWH) oil spill. Land use land cover change information is needed to help coastal zone managers and planners to understand and mitigate the impacts of environmental change on the region. This presentation discusses selective results of a current NASA-funded project in which Landsat data over a 34-year period (1974-2008) is used to produce, validate, refine, and apply land use land cover change products to aid coastal habitat conservation and restoration needs of the Mobile Bay National Estuary Program (MB NEP). The project employed a user defined classification scheme to compute LULC change mapping products for the entire region, which includes the majority of Mobile and Baldwin counties. Additional LULC change products have been computed for select coastal HUC-12 sub-watersheds adjacent to either Mobile Bay or the Gulf of Mexico, as part of the MB NEP watershed profile assessments. This presentation will include results of additional analyses of LULC change for sub-watersheds that are currently high priority areas, as defined by MB NEP. Such priority sub-watersheds include those that are vulnerable to impacts from the DWH oil spill, as well as sub-watersheds undergoing urbanization. Results demonstrating the nature and permanence of LULC change trends for these higher priority sub-watersheds and results characterizing change for the entire 34-year period and at approximate 10-year intervals across this period will also be presented. Future work will include development of value-added coastal habitat quality

PRIMARILY RESULTS OF PHYTOPLANKTON DNA AND VARIATION TO ENVIRONMENTAL FACTORS IN DURRES`S BAY COASTAL WATERS (ALBANIA

Directory of Open Access Journals (Sweden)

Laura Gjyli

2013-10-01

Full Text Available After isolation of phytoplankton DNA in coastal waters of Durres Bay, Albania, quantification and analysis of quality were investigated with spectrophotometric analysis. Analysis of UV absorption by the nucleotides provides a simple and accurate estimation of the concentration of nucleic acids in a sample. This method is however limited by the quantity of DNA and the purity of the preparation. Also biotic environment factors as Chlorophyll a and abiotic environment factors as temperature, salinity, pH, dissolved oxygen, turbidity, nitrate, phosphate were investigated to assess DNA quantities in different environment conditions. The Chlorophyll a was studied also to access the level of trophy. The sample stations were: Golem Beach (GB, Channel of Plepa (ChP, Hekurudha Beach (HB, Ex-Fuel Quay in Marine Durres Harbour (EFQ, Water Channel of Durres City (WChDC and Currila Beach (CB. Samples are taken in one meter depth from the water surface. Water samples were collected monthly from April to October 2011. The most abundant stations with phytoplankton DNA are Channel of Plepa and Water Channel of Durres City. This confirms that there are spills of fresh waters, sewage or agricultural water spills, often discharge in coastal waters. Referring Mutliple Regression Analysis and single regression analysis, the association between phytoplankton DNA and environment factors was strong (R2 = 0.75. Basing in single correlation and statistically significance (p-value ≤ 0.05, the enviroment factors that correlated to phytoplankton DNA were pH, salinity and phosphate; explaining thus the variation of total phytoplankton in Durres Bay coastal waters.

Baseline mercury and zinc concentrations in terrestrial and coastal organisms of Admiralty Bay, Antarctica

International Nuclear Information System (INIS)

Rodrigues dos Santos, Isaac; Silva-Filho, Emmanoel Vieira; Schaefer, Carlos; Maria Sella, Silvia; Silva, Carlos A.; Gomes, Vicente; Passos, Maria Jose de A.C.R.; Phan Van Ngan

2006-01-01

This paper provides the first quantitative information on mercury in soil, coastal sediment, and in characteristic organisms of terrestrial and shallow coastal marine ecosystems from Admiralty Bay (King George Island, Antarctica). As expected for a remote area, mercury content is low in abiotic components of the ecosystem, and probably similar to natural levels. Mercury also occurs in very low concentrations in the vegetation, invertebrates and fish. These low mercury levels may be due to sulphide formation in reducing sediments of this environment. Higher concentrations of mercury occurred in bird feathers and mammal hair, indicating biomagnification. This was not found for Zinc. These results may be useful as a reference background to detect future inputs of trace elements in this remote area of the earth. Terrestrial vegetation and bird feathers are suggested as target regional biomonitors. - Low levels of mercury and zinc occurred in soil and plant samples from Antarctica, but high levels occurred in birds and mammals

Application of the Hyperspectral Imager for the Coastal Ocean to Phytoplankton Ecology Studies in Monterey Bay, CA, USA

Directory of Open Access Journals (Sweden)

John P. Ryan

2014-01-01

Full Text Available As a demonstrator for technologies for the next generation of ocean color sensors, the Hyperspectral Imager for the Coastal Ocean (HICO provides enhanced spatial and spectral resolution that is required to understand optically complex aquatic environments. In this study we apply HICO, along with satellite remote sensing and in situ observations, to studies of phytoplankton ecology in a dynamic coastal upwelling environment—Monterey Bay, CA, USA. From a spring 2011 study, we examine HICO-detected spatial patterns in phytoplankton optical properties along an environmental gradient defined by upwelling flow patterns and along a temporal gradient of upwelling intensification. From a fall 2011 study, we use HICO’s enhanced spatial and spectral resolution to distinguish a small-scale “red tide” bloom, and we examine bloom expansion and its supporting processes using other remote sensing and in situ data. From a spectacular HICO image of the Monterey Bay region acquired during fall of 2012, we present a suite of algorithm results for characterization of phytoplankton, and we examine the strengths, limitations, and distinctions of each algorithm in the context of the enhanced spatial and spectral resolution.

Eicosapentaenoic and docosahexaenoic acids enriched polyunsaturated fatty acids from the coastal marine fish of Bay of Bengal and their therapeutic value.

Science.gov (United States)

Bera, Rabindranath; Dhara, Tushar K; Bhadra, Ranjan; Majumder, Gopal C; Sen, Parimal C

2010-12-01

Eicosapentaenoic acid (EPA)/docosahexaenoic acid (DHA) enriched polyunsaturated fatty acids (PUFA) significantly present in marine fish oil emerge as preventive agents for combating many health problems specially in chronic or metabolic disorders. The fish in the coastal area of Bay of Bengal has remained unexplored with respect to EPA/DHA enriched PUFA content in its oils, although it may be a potential source in harnessing the health benefit. In this study, seven varieties of the coastal fish were analysed for the content of EPA/DHA. The one locally known as lotte, (Harpadon nehereus) though has low content of total lipids, was found to have high EPA/DHA in its oil. The phospholipids rich fraction was extracted from the total fish oil. The EPA/DHA enriched PUFA was isolated to investigate the potential use for health benefits. EPA/DHA is found to act as protective agent against mercury poisoning studied in cell culture as well as in animal mode. It is found to be highly preventive in diabetes. The lotte is available in the coastal area of Bay of Bengal adjoining West Bengal, India in large scale and it is the first report showing EPA/DHA enriched PUFA in these fish oil that can be availed to harness in important health benefits.

The Effect of Coastal Development on Storm Surge Flooding in Biscayne Bay, Florida, USA (Invited)

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Zhang, K.; Liu, H.; Li, Y.

2013-12-01

Barrier islands and associated bays along the Atlantic and Gulf Coasts are a favorite place for both living and visiting. Many of them are vulnerable to storm surge flooding because of low elevations and constantly being subjected to the impacts of storms. The population increase and urban development along the barrier coast have altered the shoreline configuration, resulting in a dramatic change in the coastal flooding pattern in some areas. Here we present such a case based on numerical simulations of storm surge flooding caused by the1926 hurricane in the densely populated area surrounding Biscayne Bay in Miami, Florida. The construction of harbor and navigation channels, and the development of real estate and the roads connecting islands along Biscayne Bay have changed the geometry of Biscayne Bay since 1910s. Storm surge simulations show that the Port of Miami and Dodge Island constructed by human after 1950 play an important role in changing storm surge inundation pattern along Biscayne Bay. Dodge Island enhances storm surge and increases inundation in the area south of the island, especially at the mouth of Miami River (Downtown of Miami), and reduces storm surge flooding in the area north of the island, especially in Miami Beach. If the Hurricane Miami of 1926 happened today, the flooding area would be reduced by 55% and 20% in the Miami Beach and North Miami areas, respectively. Consequently, it would prevent 400 million of property and 10 thousand people from surge flooding according to 2010 U.S census and 2007 property tax data. Meanwhile, storm water would penetrate further inland south of Dodge Island and increase the flooding area by 25% in the Miami River and Downtown Miami areas. As a result, 200 million of property and five thousand people would be impacted by storm surge.

Physiological responses of coastal phytoplankton (Visakhapatnam, SW Bay of Bengal, India) to experimental copper addition.

Science.gov (United States)

Biswas, Haimanti; Bandyopadhyay, Debasmita

2017-10-01

Trace amount of copper (Cu) is essential for many physiological processes; however, it can be potentially toxic at elevated levels. The impact of variable Cu concentrations on a coastal phytoplankton community was investigated along a coastal transect in SW Bay of Bengal. A small increase in Cu supply enhanced the concentrations of particulate organic carbon, particulate organic nitrogen, biogenic silica, total pigment, phytoplankton cell and total bacterial count. At elevated Cu levels all these parameters were adversely affected. δ 13 C POM and δ 15 N POC reflected a visible signature of both beneficial and toxic impacts of Cu supply. Skeletonema costatum, the dominant diatom species, showed higher tolerance to increasing Cu levels relative to Chaetoceros sp. Cyanobacteria showed greater sensitivity to copper than diatoms. The magnitude of Cu toxicity on the phytoplankton communities was inversely related to the distance from the coast. Co-enrichment of iron alleviated Cu toxicity to phytoplankton. Copyright © 2017 Elsevier Ltd. All rights reserved.

Evidence for natural molecular hydrogen seepage associated with Carolina bays (surficial, ovoid depressions on the Atlantic Coastal Plain, Province of the USA)

Science.gov (United States)

Zgonnik, Viacheslav; Beaumont, Valérie; Deville, Eric; Larin, Nikolay; Pillot, Daniel; Farrell, Kathleen M.

2015-12-01

A study of soil gases was made in North Carolina (USA) in and around morphological depressions called "Carolina bays." This type of depression is observed over the Atlantic coastal plains of the USA, but their origin remains debated. Significant concentrations of molecular hydrogen (H2) were detected, notably around the bays. These measurements suggest that Carolina bays are the surficial expression of fluid flow pathways for hydrogen gas moving from depth to the surface. The potential mechanisms of H2 production and transport and the geological controls on the fluid migration pathways are discussed, with reference to the hypothesis that Carolina bays are the result of local collapses caused by the alteration of rock along the deep pathways of H2 migrating towards the surface. The present H2 seepages are comparable to those in similar structures previously observed in the East European craton.

Contaminant transport in Massachusetts Bay

Science.gov (United States)

Butman, Bradford

Construction of a new treatment plant and outfall to clean up Boston Harbor is currently one of the world's largest public works projects, costing about $4 billion. There is concern about the long-term impact of contaminants on Massachusetts Bay and adjacent Gulf of Maine because these areas are used extensively for transportation, recreation, fishing, and tourism, as well as waste disposal. Public concern also focuses on Stellwagen Bank, located on the eastern side of Massachusetts Bay, which is an important habitat for endangered whales. Contaminants reach Massachusetts Bay not only from Boston Harbor, but from other coastal communities on the Gulf of Maine, as well as from the atmosphere. Knowledge of the pathways, mechanisms, and rates at which pollutants are transported throughout these coastal environments is needed to address a wide range of management questions.

Heavy mineral analysis for assessing the provenance of sandy sediment in the San Francisco Bay Coastal System

Science.gov (United States)

Wong, Florence L.; Woodrow, Donald L.; McGann, Mary

2013-01-01

Heavy or high-specific gravity minerals make up a small but diagnostic component of sediment that is well suited for determining the provenance and distribution of sediment transported through estuarine and coastal systems worldwide. By this means, we see that surficial sand-sized sediment in the San Francisco Bay Coastal System comes primarily from the Sierra Nevada and associated terranes by way of the Sacramento and San Joaquin Rivers and is transported with little dilution through the San Francisco Bay and out the Golden Gate. Heavy minerals document a slight change from the strictly Sierran-Sacramento mineralogy at the confluence of the two rivers to a composition that includes minor amounts of chert and other Franciscan Complex components west of Carquinez Strait. Between Carquinez Strait and the San Francisco Bar, Sierran sediment is intermingled with Franciscan-modified Sierran sediment. The latter continues out the Gate and turns southward towards beaches of the San Francisco Peninsula. The Sierran sediment also fans out from the San Francisco Bar to merge with a Sierran province on the shelf in the Gulf of the Farallones. Beach-sand sized sediment from the Russian River is transported southward to Point Reyes where it spreads out to define a Franciscan sediment province on the shelf, but does not continue southward to contribute to the sediment in the Golden Gate area.

Coastal circulation and sediment dynamics in Maunalua Bay, Oahu, Hawaii, measurements of waves, currents, temperature, salinity, and turbidity; November 2008-February 2009

Science.gov (United States)

Storlazzi, Curt D.; Presto, M. Katherine; Logan, Joshua B.; Field, Michael E.

2010-01-01

High-resolution measurements of waves, currents, water levels, temperature, salinity and turbidity were made in Maunalua Bay, southern Oahu, Hawaii, during the 2008-2009 winter to better understand coastal circulation, water-column properties, and sediment dynamics during a range of conditions (trade winds, kona storms, relaxation of trade winds, and south swells). A series of bottom-mounted instrument packages were deployed in water depths of 20 m or less to collect long-term, high-resolution measurements of waves, currents, water levels, temperature, salinity, and turbidity. These data were supplemented with a series of profiles through the water column to characterize the vertical and spatial variability in water-column properties within the bay. These measurements support the ongoing process studies being done as part of the U.S. Geological Survey (USGS) Coastal and Marine Geology Program's Pacific Coral Reef Project; the ultimate goal of these studies is to better understand the transport mechanisms of sediment, larvae, pollutants, and other particles in coral reef settings. Project Objectives The objective of this study was to understand the temporal variations in currents, waves, tides, temperature, salinity and turbidity within a coral-lined embayment that receives periodic discharges of freshwater and sediment from multiple terrestrial sources in the Maunalua Bay. Instrument packages were deployed for a three-month period during the 2008-2009 winter and a series of vertical profiles were collected in November 2008, and again in February 2009, to characterize water-column properties within the bay. Measurements of flow and water-column properties in Maunalua Bay provided insight into the potential fate of terrestrial sediment, nutrient, or contaminant delivered to the marine environment and coral larval transport within the embayment. Such data are useful for providing baseline information for future watershed decisions and for establishing guidelines for

Sediment transport patterns in the San Francisco Bay Coastal System from cross-validation of bedform asymmetry and modeled residual flux

Science.gov (United States)

Barnard, Patrick L.; Erikson, Li H.; Elias, Edwin P.L.; Dartnell, Peter; Barnard, P.L.; Jaffee, B.E.; Schoellhamer, D.H.

2013-01-01

The morphology of ~ 45,000 bedforms from 13 multibeam bathymetry surveys was used as a proxy for identifying net bedload sediment transport directions and pathways throughout the San Francisco Bay estuary and adjacent outer coast. The spatially-averaged shape asymmetry of the bedforms reveals distinct pathways of ebb and flood transport. Additionally, the region-wide, ebb-oriented asymmetry of 5% suggests net seaward-directed transport within the estuarine-coastal system, with significant seaward asymmetry at the mouth of San Francisco Bay (11%), through the northern reaches of the Bay (7–8%), and among the largest bedforms (21% for λ > 50 m). This general indication for the net transport of sand to the open coast strongly suggests that anthropogenic removal of sediment from the estuary, particularly along clearly defined seaward transport pathways, will limit the supply of sand to chronically eroding, open-coast beaches. The bedform asymmetry measurements significantly agree (up to ~ 76%) with modeled annual residual transport directions derived from a hydrodynamically-calibrated numerical model, and the orientation of adjacent, flow-sculpted seafloor features such as mega-flute structures, providing a comprehensive validation of the technique. The methods described in this paper to determine well-defined, cross-validated sediment transport pathways can be applied to estuarine-coastal systems globally where bedforms are present. The results can inform and improve regional sediment management practices to more efficiently utilize often limited sediment resources and mitigate current and future sediment supply-related impacts.

Drivers of change in estuarine-coastal ecosystems: Discoveries from four decades of study in San Francisco Bay

Science.gov (United States)

Cloern, J.E.; Jassby, A.D.

2012-01-01

Poised at the interface of rivers, ocean, atmosphere and dense human settlement, estuaries are driven by a large array of natural and anthropogenic forces. San Francisco Bay exemplifies the fast-paced change occurring in many of the world's estuaries, bays and inland seas in response to these diverse forces. We use observations from this particularly well-studied estuary to illustrate responses to six drivers that are common agents of change where land and sea meet: water consumption and diversion; human modification of sediment supply; introduction of non-native species; sewage input; environmental policy; and climate shifts. In San Francisco Bay, responses to these drivers include, respectively, shifts in the timing and extent of freshwater inflow and salinity intrusion; decreasing turbidity; restructuring of plankton communities; nutrient enrichment; elimination of hypoxia and reduced metal contamination of biota; and food web changes that decrease resistance of the estuary to nutrient pollution. Detection of these changes and discovery of their causes through environmental monitoring have been essential for establishing and measuring outcomes of environmental policies that aim to maintain high water quality and sustain services provided by estuarine-coastal ecosystems. The wide range of variability time scales and the multiplicity of interacting drivers place heavy demands on estuarine monitoring programs. But the San Francisco Bay case study illustrates why the imperative for monitoring has never been greater.

Drivers of change in estuarine-coastal ecosystems: Discoveries from four decades of study in San Francisco Bay

Science.gov (United States)

Cloern, James E.; Jassby, Alan D.

2012-12-01

Poised at the interface of rivers, ocean, atmosphere and dense human settlement, estuaries are driven by a large array of natural and anthropogenic forces. San Francisco Bay exemplifies the fast-paced change occurring in many of the world's estuaries, bays, and inland seas in response to these diverse forces. We use observations from this particularly well-studied estuary to illustrate responses to six drivers that are common agents of change where land and sea meet: water consumption and diversion, human modification of sediment supply, introduction of nonnative species, sewage input, environmental policy, and climate shifts. In San Francisco Bay, responses to these drivers include, respectively, shifts in the timing and extent of freshwater inflow and salinity intrusion, decreasing turbidity, restructuring of plankton communities, nutrient enrichment, elimination of hypoxia and reduced metal contamination of biota, and food web changes that decrease resistance of the estuary to nutrient pollution. Detection of these changes and discovery of their causes through environmental monitoring have been essential for establishing and measuring outcomes of environmental policies that aim to maintain high water quality and sustain services provided by estuarine-coastal ecosystems. The many time scales of variability and the multiplicity of interacting drivers place heavy demands on estuarine monitoring programs, but the San Francisco Bay case study illustrates why the imperative for monitoring has never been greater.

Gradient Analysis and Classification of Carolina Bay Vegetation: A Framework for Bay Wetlands Conservation and Restoration

Energy Technology Data Exchange (ETDEWEB)

Diane De Steven,Ph.D.; Maureen Tone,PhD.

1997-10-01

This report address four project objectives: (1) Gradient model of Carolina bay vegetation on the SRS--The authors use ordination analyses to identify environmental and landscape factors that are correlated with vegetation composition. Significant factors can provide a framework for site-based conservation of existing diversity, and they may also be useful site predictors for potential vegetation in bay restorations. (2) Regional analysis of Carolina bay vegetation diversity--They expand the ordination analyses to assess the degree to which SRS bays encompass the range of vegetation diversity found in the regional landscape of South Carolina's western Upper Coastal Plain. Such comparisons can indicate floristic status relative to regional potentials and identify missing species or community elements that might be re-introduced or restored. (3) Classification of vegetation communities in Upper Coastal Plain bays--They use cluster analysis to identify plant community-types at the regional scale, and explore how this classification may be functional with respect to significant environmental and landscape factors. An environmentally-based classification at the whole-bay level can provide a system of templates for managing bays as individual units and for restoring bays to desired plant communities. (4) Qualitative model for bay vegetation dynamics--They analyze present-day vegetation in relation to historic land uses and disturbances. The distinctive history of SRS bays provides the possibility of assessing pathways of post-disturbance succession. They attempt to develop a coarse-scale model of vegetation shifts in response to changing site factors; such qualitative models can provide a basis for suggesting management interventions that may be needed to maintain desired vegetation in protected or restored bays.

Aragonite saturation state in a tropical coastal embayment dominated by phytoplankton blooms (Guanabara Bay - Brazil).

Science.gov (United States)

Cotovicz, Luiz C; Knoppers, Bastiaan A; Brandini, Nilva; Poirier, Dominique; Costa Santos, Suzan J; Abril, Gwenaël

2018-04-01

The dynamics of the aragonite saturation state (Ω arag ) were investigated in the eutrophic coastal waters of Guanabara Bay (RJ-Brazil). Large phytoplankton blooms stimulated by a high nutrient enrichment promoted the production of organic matter with strong uptake of dissolved inorganic carbon (DIC) in surface waters, lowering the concentrations of dissolved carbon dioxide (CO 2aq ), and increasing the pH, Ω arag and carbonate ion (CO 3 2- ), especially during summer. The increase of Ω arag related to biological activity was also evident comparing the negative relationship between the Ω arag and the apparent utilization of oxygen (AOU), with a very close behavior between the slopes of the linear regression and the Redfield ratio. The lowest values of Ω arag were found at low-buffered waters in regions that receive direct discharges from domestic effluents and polluted rivers, with episodic evidences of corrosive waters (Ω arag <1). This study showed that the eutrophication controlled the variations of Ω arag in Guanabara Bay. Copyright © 2017 Elsevier Ltd. All rights reserved.

Organic Carbon and Trace Element Cycling in a River-Dominated Tidal Coastal Wetland System (Tampa Bay, FL, USA)

Science.gov (United States)

Moyer, R. P.; Smoak, J. M.; Engelhart, S. E.; Powell, C. E.; Chappel, A. R.; Gerlach, M. J.; Kemp, A.; Breithaupt, J. L.

2016-02-01

Tampa Bay is the largest open water, river-fed estuary in Florida (USA), and is characterized by the presence of both mangrove and salt marsh ecosystems. Both coastal wetland systems, and small rivers such as the ones draining into Tampa Bay have historically been underestimated in terms of their role in the global carbon and elemental cycles. Climate change and sea-level rise (SLR) are major threats in Tampa Bay and stand to disrupt hydrologic cycles, compromising sediment accumulation and the rate of organic carbon (OC) burial. This study evaluates organic carbon content, sediment accumulation, and carbon burial rates in salt marsh and mangrove ecosystems, along with measurements of fluxes of dissolved OC (DOC) and trace elements in the water column of the Little Manatee River (LMR) in Tampa Bay. The characterization of OC and trace elements in tidal rivers and estuaries is critical for quantitatively constraining these systems in local-to-regional scale biogeochemical budgets, and provide insight into biogeochemical processes occurring with the estuary and adjacent tidal wetlands. Material fluxes of DOC and trace elements were tied to discharge irrespective of season, and the estuarine habitats removed 15-65% of DOC prior to export to Tampa Bay and the Gulf of Mexico. Thus, material is available for cycling and burial within marsh and mangrove peats, however, LMR mangrove peats have higher OC content and burial rates than adjacent salt marsh peats. Sedimentary accretion rates in LMR marshes are not currently keeping pace with SLR, thus furthering the rapid marsh-to-mangrove conversions that have been seen in Tampa Bay over the past half-century. Additionally, wetlands in Tampa Bay tend to have a lower rate of carbon burial than other Florida tidal wetlands, demonstrating their high sensitivity to climate change and SLR.

Nutrient fluxes across sediment-water interface in Bohai Bay Coastal Zone, China.

Science.gov (United States)

Mu, Di; Yuan, Dekui; Feng, Huan; Xing, Fangwei; Teo, Fang Yenn; Li, Shuangzhao

2017-01-30

Sediment cores and overlying water samples were collected at four sites in Tianjin Coastal Zone, Bohai Bay, to investigate nutrient (N, P and Si) exchanges across the sediment-water interface. The exchange fluxes of each nutrient species were estimated based on the porewater profiles and laboratory incubation experiments. The results showed significant differences between the two methods, which implied that molecular diffusion alone was not the dominant process controlling nutrient exchanges at these sites. The impacts of redox conditions and bioturbation on the nutrient fluxes were confirmed by the laboratory incubation experiments. The results from this study showed that the nutrient fluxes measured directly from the incubation experiment were more reliable than that predicted from the porewater profiles. The possible impacts causing variations in the nutrient fluxes include sewage discharge and land reclamation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Coastal dynamics of Garabogazköl bay of Caspian Sea

Science.gov (United States)

Kurbanov, Redzhep

2016-04-01

Garabogazköl is extremely interesting object for the study of coastal evolution and Caspian sea paleogeography. Bay plays an important role in evolution of the Caspian basin, as a major area of permanent loss of sea water, the volume of which varies in different years from 17 to 23 km3/year, averaging about 20.3 km3/year. Termination of runoff into the bay would provide annual Caspian Sea level rise of about 3 cm. Despite the large-scale research of the coast of the Caspian Sea during the Soviet era, Garabogazköl was generally poorly studied, mostly describing sedimentation patterns of salt deposits (associated with the production of sulfates). The basis of our study was the materials of remote sensing (satellite imagery), supported by field research, description of geomorphological structure of coasts. As known, the Caspian Sea level was at the lowest elevations from 1970 to 1985, ranging from -28.6 to -29.01 m. The creation of the dam in 1980 completely blocked Caspian water inflow into the Gulf, resulting even more drastic reduction in its area, which decreased by 3 times (from 18 to 6 thousand. km2), with depth less than 50 cm. In mid-1992, when the level of the Caspian Sea has risen by more than 2 meters over the level of 1978, the dam was destroyed. The obtained data allowed characterizing the peculiarities of the coast of the Gulf in these conditions. During the start of the coastal retreat first appeared drained relatively shallow northern and western parts. During this period the processes of accumulation were predominate. There was the deposition of thick (up to 1 m) salt horizon. Dominating wind-surge processes resulted relatively smoothed surface, filling rugged topography by terrigenous material and salt. After the explosion of the dam in 1992, the bay was quickly filled with water and in the next 3-4 years is completely covered the Gara-Bogaz depression. In general, a high stability of the coastline of the Gulf observed through analysis of the last

Applying post classification change detection technique to monitor an Egyptian coastal zone (Abu Qir Bay

Directory of Open Access Journals (Sweden)

Mamdouh M. El-Hattab

2016-06-01

Full Text Available Land cover changes considered as one of the important global phenomena exerting perhaps one of the most significant effects on the environment than any other factor. It is, therefore, vital that accurate data on land cover changes are made available to facilitate the understanding of the link between land cover changes and environmental changes to allow planners to make effective decisions. In this paper, the post classification approach was used to detect and assess land cover changes of one of the important coastal zones in Egypt, Abu Qir Bay zone, based on the comparative analysis of independently produced classification images of the same area at different dates. In addition to satellite images, socioeconomic data were used with the aid of land use model EGSLR to indicate relation between land cover and land use changes. Results indicated that changes in different land covers reflected the changes in occupation status in specific zones. For example, in the south of Idku Lake zone, it was observed that the occupation of settlers changed from being unskilled workers to fishermen based on the expansion of the area of fish farms. Change rates increased dramatically in the period from 2004 to 2013 as remarkable negative changes were found especially in fruits and palm trees (i.e. loss of about 66 km2 of land having fruits and palm trees due to industrialization in the coastal area. Also, a rapid urbanization was monitored along the coastline of Abu Qir Bay zone due to the political conditions in Egypt (25th of January Revolution within this period and which resulted to the temporary absence of monitoring systems to regulate urbanization.

1999 RoxAnn Data Points from Apalachicola Bay, Florida

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Apalachicola Bay National Estuarine Research Reserve and the NOAA Office for Coastal Management worked together to map benthic habitats within Apalachicola Bay,...

Concentration of PSP (Paralytic Shellfish Poisoning) Toxin On Shellfish From Inner Ambon Bay and Kao Bay North Halmahera

Science.gov (United States)

Pello, F. S.; Haumahu, S.; Huliselan, N. V.; Tuapattinaja, M. A.

2017-10-01

The Inner Ambon Bay and Kao Bay have potential on fisheries resources which one of them is molluscs. Molluscs especially for class bivalve have economical values and are consumed by coastal community. The research had been done to analyze saxitoxin (STX) concentration on bivalves from Kao Bay and Inner Ambon Bay. The Saxitoxin Elisa Test Kit Protocol was used to determine saxitoxin concentration. The measurement showed that the highest concentration of saxitoxin (392.42 µg STXeq/100g shellfish meat) was Gafrarium tumidum from Ambon Bay, whereas concentration of saxitoxin (321.83 µg STXeq/100g shellfish meat) was Mactra mera from Kao Bay

Comparison of Two Simplification Methods for Shoreline Extraction from Digital Orthophoto Images

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Bayram, B.; Sen, A.; Selbesoglu, M. O.; Vārna, I.; Petersons, P.; Aykut, N. O.; Seker, D. Z.

2017-11-01

The coastal ecosystems are very sensitive to external influences. Coastal resources such as sand dunes, coral reefs and mangroves has vital importance to prevent coastal erosion. Human based effects also threats the coastal areas. Therefore, the change of coastal areas should be monitored. Up-to-date, accurate shoreline information is indispensable for coastal managers and decision makers. Remote sensing and image processing techniques give a big opportunity to obtain reliable shoreline information. In the presented study, NIR bands of seven 1:5000 scaled digital orthophoto images of Riga Bay-Latvia have been used. The Object-oriented Simple Linear Clustering method has been utilized to extract shoreline of Riga Bay. Bend and Douglas-Peucker methods have been used to simplify the extracted shoreline to test the effect of both methods. Photogrammetrically digitized shoreline has been taken as reference data to compare obtained results. The accuracy assessment has been realised by Digital Shoreline Analysis tool. As a result, the achieved shoreline by the Bend method has been found closer to the extracted shoreline with Simple Linear Clustering method.

COMPARISON OF TWO SIMPLIFICATION METHODS FOR SHORELINE EXTRACTION FROM DIGITAL ORTHOPHOTO IMAGES

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B. Bayram

2017-11-01

Full Text Available The coastal ecosystems are very sensitive to external influences. Coastal resources such as sand dunes, coral reefs and mangroves has vital importance to prevent coastal erosion. Human based effects also threats the coastal areas. Therefore, the change of coastal areas should be monitored. Up-to-date, accurate shoreline information is indispensable for coastal managers and decision makers. Remote sensing and image processing techniques give a big opportunity to obtain reliable shoreline information. In the presented study, NIR bands of seven 1:5000 scaled digital orthophoto images of Riga Bay-Latvia have been used. The Object-oriented Simple Linear Clustering method has been utilized to extract shoreline of Riga Bay. Bend and Douglas-Peucker methods have been used to simplify the extracted shoreline to test the effect of both methods. Photogrammetrically digitized shoreline has been taken as reference data to compare obtained results. The accuracy assessment has been realised by Digital Shoreline Analysis tool. As a result, the achieved shoreline by the Bend method has been found closer to the extracted shoreline with Simple Linear Clustering method.

Submarine groundwater discharge as an important nutrient source influencing nutrient structure in coastal water of Daya Bay, China

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Wang, Xuejing; Li, Hailong; Zheng, Chunmiao; Yang, Jinzhong; Zhang, Yan; Zhang, Meng; Qi, Zhanhui; Xiao, Kai; Zhang, Xiaolang

2018-03-01

As an important nutrient source for coastal waters, submarine groundwater discharge (SGD) has long been largely ignored in Daya Bay, China. In this study, we estimate the fluxes of SGD and associated nutrients into this region using a 224Ra mass balance model and assess the contribution/importance of nutrients by SGD, benthic sediments, local rivers, and atmospheric deposition. The results of 224Ra mass balance show that the estimated SGD ranges from (2.76 ± 1.43) × 106 m3/d to (1.03 ± 0.53) × 107 m3/d with an average of (6.32 ± 2.42) × 106 m3/d, about 16 times the total discharge rate of local rivers. The nutrient loading from SGD is estimated to be (1.05-1.99) × 105 mol/d for NO3-N, (4.04-12.16) × 103 mol/d for DIP, and (3.54-11.35) × 105 mol/d for Si. Among these considered nutrient sources, we find that SGD is the primary source for Si and NO3-N, contributing 68% and 42% of all considered sources, respectively. The atmospheric NO3-N flux is comparable to that from SGD. The local rivers are the most important source for DIP, contributing 75% of all considered sources. SGD with high N:P ratio (NO3-N/DIP) of 37.0 delivers not only a large quantity of nutrients, but also changes nutrient structure in coastal water. Based on a DIP budget, primary productivity is evaluated to be 54-73 mg C/m2 d, in which SGD accounts for approximately 30% of total production. This study indicates that SGD is a key source of nutrients to coastal waters and may cause an obvious change of primary production and nutrient structure in Daya Bay.

Vulnerability of Coastal Crop Land to Climate Change in the Northern Part of Bay of Bengal: Issues, Challenges and Future Prospects

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Kamal, A. H. M.

2015-12-01

The coastal communities of northeastern part of Bay of Bengal are used to live and survive through facing different types of natural disasters since primitive time. Among the natural disasters, salinity intrusion due to climate change and sea level rise in the coastal agriculture land is the major unpleasant incident now days. Because of that wide area of the coastal agricultural land, coastal forest, drinking water facilities and fresh water availability are in critical condition which may cause 40 million people of 147 coastal districts covering 47201 km area are placed in danger. The nation wide assessment on the detected of coastal soil and water salinity is not conducted since 9 years. The survey on the coastal soil salinity on 1973 and 2000 found that the saline effected land is increased from 0.83 million ha to 1.20 million ha within 27 years. It is assumed that at present the rate of salinity intrusion in the coastal agriculture land will be higher than those of 1973 and 2000. The soil salinity was recorded 18-20 psu after AILA in the south-eastern coast of Bangladesh and increased further 2-4 psu due to low precipitation which causes crop burning. This paper aims to know the salinity intrusion in the coastal soil and water of Bangladesh, which would help to plan and improvement of the sustainable agriculture production. Study revealed that to face any extra stresses on the coastal agriculture land due to climate change requires extensive inventory, awareness activities, mitigation measures, adaptation techniques and extension of indigenous technology.

Sediment grab data from October 1999 in Apalachicola Bay, Florida

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National Oceanic and Atmospheric Administration, Department of Commerce — The Apalachicola Bay National Estuarine Research Reserve and the NOAA Office for Coastal Management worked together to map benthic habitats within Apalachicola Bay,...

Processes influencing the transport and fate of contaminated sediments in the coastal ocean: Boston Harbor and Massachusetts Bay

Science.gov (United States)

Alexander, P. Soupy; Baldwin, Sandra M.; Blackwood, Dann S.; Borden, Jonathan; Casso, Michael A.; Crusius, John; Goudreau, Joanne; Kalnejais, Linda H.; Lamothe, Paul J.; Martin, William R.; Martini, Marinna A.; Rendigs, Richard R.; Sayles, Frederick L.; Signell, Richard P.; Valentine, Page C.; Warner, John C.; Bothner, Michael H.; Butman, Bradford

2007-01-01

Most of the major urban centers of the United States including Boston, New York, Washington, Chicago, New Orleans, Miami, Los Angeles, San Francisco, and Seattle—are on a coast (fig. 1.1). All of these cities discharge treated sewage effluent into adjacent waters. In 2000, 74 percent of the U.S. population lived within 200 kilometers (km) of the coast. Between 1980 and 2002, the population density in coastal communities increased approximately 4.5 times faster than in noncoastal areas of the U.S. (Perkins, 2004). More people generate larger volumes of wastes, increase the demands on wastewater treatment, expand the area of impervious land surfaces, and use more vehicles that contribute contaminants to street runoff. According to the National Coastal Condition Report II (U.S. Environmental Protection Agency, 2005a), on the basis of coastal habitat, water and sediment quality, benthic index, and fish tissue, the overall national coastal condition is only poor to fair and the overall coastal condition in the highly populated Northeast is poor. Scientific information helps managers to prioritize and regulate coastal-ocean uses that include recreation, commercial fishing, transportation, waste disposal, and critical habitat for marine organisms. These uses are often in conflict with each other and with environmental concerns. Developing a strategy for managing competing uses while maintaining sustainability of coastal resources requires scientific understanding of how the coastal ocean system behaves and how it responds to anthropogenic influences. This report provides a summary of a multidisciplinary research program designed to improve our understanding of the transport and fate of contaminants in Massachusetts coastal waters. Massachusetts Bay and Boston Harbor have been a focus of U.S. Geological Survey (USGS) research because they provide a diverse geographic setting for developing a scientific understanding of the geology, geochemistry, and oceanography of

Increased SST and Frequent Occurrence of Rough Sea Events in the Bay of Bengal: Implications for livelihoods of Coastal Populace in Bangladesh (Invited)

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Ahmed, A. U.

2010-12-01

Bangladesh is a densely populated low-lying deltaic country, widely known to be highly vulnerable to climate change. High vulnerability is caused mainly by geophysical factors, compounded by a number of social and economic factors such as large population, high incidence of poverty and malnutrition, glaring social inequity, and poor governance. The coastal zone facing the Bay of Bengal is particularly vulnerable to hazards such as sea level rise, salinity intrusion, high wave interaction and erosion, saline water-logging, and cyclonic storm surges. The sea surface temperature (SST) in the northern Indian Ocean has recently been exhibiting a general increasing trend, with a net rise of about 0.45°C over the past four decades. This has been attributed to climate change. The warming, identified by marked increase in SST, has been causing a significant increase in the formation of ‘low pressures’ to ‘deep depressions’ in the bay. Consequently, the tidal activities on the surface have become rough and turbulent, triggering a number of problems for the livelihoods of coastal population of Bangladesh. The coastal fisherfolk communities represent poorest of the poor, who can hardly earn a livelihood from traditional fishing practices. Their prime fishing period coincides with Monsoon and post-monsoon seasons combined, when the bay becomes rough, turbulent, and unsuitable for artisanal fishing. With increasing frequency of occurrence of ‘rough sea events’, the coastal fishermen are forced to stay out of action in anticipation of complete loss of investment made for fishing trips or forced to abandon incomplete fishing trips - the latter causing heavy financial losses. As a consequence of too many incomplete fishing trips and scanty return from subsequent investments, livelihoods of coastal fisherfolk have been devastated. Coastal farmers have been maintaining their livelihoods, where the state invested for building surge protecting embankments to offer �

POTENTIAL HAZARDS OF SEDIMENT IN KENDARI BAY, SOUTHEAST SULAWESI

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Nur Adi Kristanto

2017-07-01

Full Text Available Kendari bay is located in front of Kendari city. There are two harbors in the inner part of bay which very important to support economic activities such as shipping and passenger transportation. The result of coastal characteristic mapping and physical oceanography survey show various coastal morphology, vegetation, weathering processes, sedimentation, currents, and water depth and sea floor morphology. Kendari bay is an enclosed bay; the area is wide in the inner part and narrow in mouth of bay (outlet, the morphology look like a bottle’s neck. Numerous mouth rivers are concentrate around the bay. The rivers load material from land since erosion on land is intensive enough. There is indication that sediment supplies from land trough river mouth not equivalent with outlet capacity. Sediment load is trapped in the inner bay caused the outlet morphology. So high sediment rate play an important role in the process of shallow of water depth in Kendari bay. This condition make the Kendari bay is a prone area of sediment hazard due to height rate of sedimentary process. Therefore, to anticipate the hazards, precaution should be taken related to the Kendari bay as the center of activities in southeast of Sulawesi. The further survey is needed such as marine geotechnique and on land environmental to collect data, which can be used as database for development planning. Key words: Potential hazard, sediment, Kendari Bay Teluk

Spatial Analysis of Potentially Preventable Pneumonia and Asthma Hospitalizations for Children in the Texas Coastal Bend Area

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Lin, Na

Pneumonia and asthma, two common Ambulatory Care Sensitive Conditions (ACSCs), were two top reasons for the admission of children to the hospitals and emergency rooms in the United States in 2011. Pneumonia and asthma are potentially preventable if the child's environment is properly managed. Underlying vulnerabilities such as low socioeconomic status (SES) and proximity to air pollution play an important role in ACSCs hospitalization. Pneumonia and asthma are two common reasons for hospitalizations among children and missed school days in Texas Coastal Bend Area. This thesis examines the relationships between neighborhood socioeconomic characteristics, meteorological conditions and children ACSCs hospitalization, including pneumonia and asthma among children age 0-17 in this area. Hospital discharge data from 2007 to 2009 based on Zip Code Tabulation Area (ZCTA) were examined along with American Community Survey (ACS) data, air pollution data from Environmental Protection Agency (EPA) and temperature data from National Climatic Data Center (NCDC). Hotspot and Local Moran's I analyses were applied to identify the concentrations of the illnesses. Two regressions (OLS and GWR) were applied to identify factors that contribute the most to ACSCs hospitalization. Pearson's correlation was calculated to examine the relationship between meteorological condition and child hospitalization for asthma and pneumonia. A human subject survey was conducted to examine the relationships between neighborhood environment and children asthma cases. The main finding was that children from families with health insurance, children from single father families and children from poor families were more likely to visit hospital for ACSCs and pneumonia care. "Hispanic families" and especially "Hispanic families with father but no mother" also contributed most to child hospitalization for ACSCs and pneumonia, suggesting that family preventative health care education is needed for Hispanic

Bristol Bay, Alaska Subarea ESI: T_MAMMAL (Terrestrial Mammal Polygons)

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National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for brown bears in the Bristol Bay Subarea. The Subarea includes marine and coastal areas of Bristol Bay...

Seasonal variability of coastal water quality in bay of Bengal and Palk Strait, Tamilnadu, Southeast Coast of India

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Viswanathan Srinivasan

2013-10-01

Full Text Available The aim of this work was to study the physicochemical parameters of water quality collected from 12 sampling stations from Topputhurai to Muthupet in Vedaranyam located on the southeast coast of India from January to December 2008. Results showed that the DO and nutrients were the maximum in the Bay of Bengal during the monsoon period. High concentration of the nutrients in summer season was obtained near the Muthupet mangroves compared to the Palk Strait, which showed that this acted as a source of nutrients to the adjacent coastal waters. Low concentrations of the nutrients observed in the monsoon could be attributed to the terrestrial runoff from Muthupet lagoon. The physicochemical characteristics of coastal waters between the Point Calimere and Muthupet could be used as a baseline data for the monitoring, conservation and management of Point Calimere Wildlife and Bird sanctuary, Great Vedaranyam swamp and Muthupet mangrove ecosystem.

Stable Isotopic Shifts in Fish Bones from Multiple Archeological Coastal Middens in Penobscot Bay, Maine

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Harris, C.; Johnson, B.; Ambrose, W. G.; Bourque, B.; Dostie, P.; Crowley, E.

2010-12-01

The carbon and nitrogen stable isotope compositions of collagen extracted from well-preserved archeological fish bones has the potential to provide useful information on fish diets and food web dynamics over time. Previous work on the Turner Farm archaeological site in Penobscot Bay, Gulf of Maine, reveals significant shifts in fish diets have occurred since European colonization (post 1620’s). The objective of the present study was to analyze samples from other archaeological sites within Penobscot Bay to characterize the spatial extent of the isotopic shift measured at Turner Farm. Stratified cod, flounder, and sculpin bones were analyzed from eight coastal middens located approximately 50km apart from one another within Penobscot Bay. The bones were sampled from three time horizons (0kya, 0.5-1kya, and 2.2-2.4kya). All bone samples were demineralized in 0.2M HCl at 4°C for 2 to 7 days and then extracted in 0.25M NaOH at 4°C for 1 to 2 hours. After freeze-drying, the bulk isotopic composition of each sample was analyzed using the EA-IRMS. In all stratigraphic horizons analyzed, cod were more enriched in δ13C and δ15N than sculpin, and flounder were the most depleted in δ13C and δ15N . However, the isotopic offsets between the fish species decreased from 2.4kya to the present. The nitrogen isotope composition was relatively constant over time and space for all species, implying that trophic levels for the fishes analyzed have not changed significantly in Penobscot Bay for the last 2,400 years. The carbon isotope composition also appears to be constant spatially in Penobscot Bay, however, the modern signal was more depleted than the paleo signal in all three species. The difference between the modern and paleo δ13C is ~5‰ for cod and flounder, and ~9‰ for sculpin. These shifts may, in part, be explained by decreases in both primary producer and prey species diversity, as kelp forests replace eelgrass beds in the Gulf of Maine.

Sediment profile image data from October 1999 in Apalachicola Bay, Florida

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National Oceanic and Atmospheric Administration, Department of Commerce — The Apalachicola Bay National Estuarine Research Reserve and the NOAA Office for Coastal Management worked together to map benthic habitats within Apalachicola Bay,...

Assessment of organotin and tin-free antifouling paints contamination in the Korean coastal area.

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Lee, Mi-Ri-Nae; Kim, Un-Jung; Lee, In-Seok; Choi, Minkyu; Oh, Jeong-Eun

2015-10-15

Twelve organotins (methyl-, octyl-, butyl-, and phenyl-tin), and eight tin-free antifouling paints and their degradation products were measured in marine sediments from the Korean coastal area, and Busan and Ulsan bays, the largest harbor area in Korea. The total concentration of tin-free antifouling paints was two- to threefold higher than the total concentration of organotins. Principal component analysis was used to identify sites with relatively high levels of contamination in the inner bay area of Busan and Ulsan bays, which were separated from the coastal area. In Busan and Ulsan bays, chlorothalonil and DMSA were more dominant than in the coastal area. However, Sea-Nine 211 and total diurons, including their degradation products, were generally dominant in the Korean coastal area. The concentrations of tin and tin-free compounds were significantly different between the east and west coasts. Copyright © 2015 Elsevier Ltd. All rights reserved.

San Francisco Bay Area CHARG: Coastal Hazards Adaptation Resiliency Group, a Multi-Jurisdictional Collaboration to Develop Innovative Regional Solutions to Address Sea Level Rise and Improve Shoreline Resiliency

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Saleh, R.

2017-12-01

For a challenge as complex and far-reaching as sea level rise and improving shoreline resiliency, strong partnerships between scientists, elected officials, decision-makers, and the general public are the only way that effective solutions can be developed. The San Francisco Bay, like many similar sheltered water coastal environments (for example, Galveston Bay, Tampa Bay, or Venetian Lagoon) offers a unique opportunity for multiple jurisdictions to collaborate to address sea level rise on a regional basis. For the San Francisco Bay, significant scientific progress has been made in building a real-time simulation model for riverine and Bay hydrodynamics. Other major scientific initiatives, such as morphology mapping, shoreline mapping, and a sediment budget are also underway. In 2014, leaders from the Bay Area science, engineering, planning, policy, elected, and regulatory communities representing jurisdictions around the Bay joined together to address sea level rise. The group includes people from local, regional, state, and federal agencies and organizations. Together, CHARG (Coastal Hazards Adaptation Resiliency Group) established a collective vision and approach to implementing regional solutions. Decision-makers within many Bay Area jurisdictions are motivated to show demonstrable progress toward addressing sea level rise. However, the cost to implement shoreline resiliency solutions will be very large, and must be founded on strong science.CHARG is now tackling several key technical challenges. One is to develop science-based guidelines for local jurisdictions to determine when a project is local, sub-regional, or regional. Concurrently, several organizations are planning or implementing pilot shoreline resiliency projects and other programs. Many creative regional solutions are possible in a sheltered water environment that simply would not be feasible along the open coast. By definition, these solutions cannot be undertaken by one entity alone. Large

Phosphorus speciation, transformation, and preservation in the coastal area of Rushan Bay.

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Liu, Jun; Zang, Jiaye; Zhao, Chenying; Yu, Zhigang; Xu, Bochao; Li, Jingxi; Ran, Xiangbin

2016-09-15

Phosphorus (P) speciation, burial, and transformation are poorly constrained under low-oxygen conditions. Sequential chemical extraction techniques, in-situ incubation, and laboratory incubation were employed to explore P cycling in the low-oxygen area of coastal Rushan. The study determined that the total P concentrations in the coastal area of Rushan Bay were higher than those of other China shelf seas, and largely affected by anthropogenic activities. The phosphate (DRP) fluxes in the study area calculated using an incubation method (0-1960μmolm(-2)day(-)(1)) and measured based on pore water gradients (1.5-50.4μmolm(-2)day(-)(1)) were both highly correlated with oxygen conditions. Sediment incubations showed that DRP diffusion from the sediment mainly originates from Fe-P and Auth-P dissolution and that Org-P recycling contributed only a small portion of the total released P pool. The benthic phosphate flux can be 60 times higher under low bottom-water oxygen levels of 63-150μmolL(-1) than under oxygen levels exceeding 150μmolL(-1) in the study area. The P accumulation rates and burial efficiencies in this study area ranged from 16.5-33.3μmolcm(-2)year(-1) and 81.1-83.4%, respectively, and were regulated by the oxygen level and diffusive DRP flux. This study indicates that low oxygen levels between 63 and 150μmol significantly govern P transformation and preservation in the sediment and P pools in the water column. Copyright © 2016 Elsevier B.V. All rights reserved.

Trace/heavy metal pollution monitoring in estuary and coastal area of Bay of Bengal, Bangladesh and implicated impacts.

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Kibria, Golam; Hossain, Md Maruf; Mallick, Debbrota; Lau, T C; Wu, Rudolf

2016-04-15

Using artificial mussels (AMs), this study reports and compares time-integrated level of eleven trace metals (Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, U, Zn) in Karnafuli River estuary and coastal area of the Bay of Bengal, Bangladesh. Through this study, "hot spots" of metal pollution were identified. The results may demonstrate that the Karnafuli Estuary, and adjacent coastal area of Chittagong, Bangladesh are highly polluted by high risk metals (cadmium, chromium, copper, mercury, nickel, lead, uranium). Agricultural, domestic and industrial wastes directly discharged into the waterways have been identified as the main causes of metal pollution in Chittagong, Bangladesh. The high level of metal pollution identified may impact on local water quality, and seafood catch, livelihoods of people and public health resulting from seafood consumption. There is a need for regular monitoring to ascertain that local water quality with respect to metal levels are within acceptable levels to safeguards both environmental health and public health. Copyright © 2016 Elsevier Ltd. All rights reserved.

A multi-scale ensemble-based framework for forecasting compound coastal-riverine flooding: The Hackensack-Passaic watershed and Newark Bay

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Saleh, F.; Ramaswamy, V.; Wang, Y.; Georgas, N.; Blumberg, A.; Pullen, J.

2017-12-01

Estuarine regions can experience compound impacts from coastal storm surge and riverine flooding. The challenges in forecasting flooding in such areas are multi-faceted due to uncertainties associated with meteorological drivers and interactions between hydrological and coastal processes. The objective of this work is to evaluate how uncertainties from meteorological predictions propagate through an ensemble-based flood prediction framework and translate into uncertainties in simulated inundation extents. A multi-scale framework, consisting of hydrologic, coastal and hydrodynamic models, was used to simulate two extreme flood events at the confluence of the Passaic and Hackensack rivers and Newark Bay. The events were Hurricane Irene (2011), a combination of inland flooding and coastal storm surge, and Hurricane Sandy (2012) where coastal storm surge was the dominant component. The hydrodynamic component of the framework was first forced with measured streamflow and ocean water level data to establish baseline inundation extents with the best available forcing data. The coastal and hydrologic models were then forced with meteorological predictions from 21 ensemble members of the Global Ensemble Forecast System (GEFS) to retrospectively represent potential future conditions up to 96 hours prior to the events. Inundation extents produced by the hydrodynamic model, forced with the 95th percentile of the ensemble-based coastal and hydrologic boundary conditions, were in good agreement with baseline conditions for both events. The USGS reanalysis of Hurricane Sandy inundation extents was encapsulated between the 50th and 95th percentile of the forecasted inundation extents, and that of Hurricane Irene was similar but with caveats associated with data availability and reliability. This work highlights the importance of accounting for meteorological uncertainty to represent a range of possible future inundation extents at high resolution (∼m).

Predominant Nearshore Sediment Dispersal Patterns in Manila Bay

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Fernando Siringan

1997-12-01

Full Text Available Net nearshore sediment drift patterns in Manila Bay were determined by combining the coastal geomorphology depicted in 1 : 50,000scale topographic maps and Synthetic Aperture Radar (SAR images, with changes in shoreline position and predominant longshore current directions derived from the interaction of locally generated waves and bay morphology.Manila Bay is fringed by a variety of coastal subenvironments that reflect changing balances of fluvial, wave, and tidal processes. Along the northern coast, a broad tidal-river delta plain stretching from Bataan to Bulacan indicates the importance of tides, where the lateral extent of tidal influences is amplified by the very gentle coastal gradients. In contrast, along the Cavite coast sandy strandplains, spits, and wave-dominated deltas attest to the geomorphic importance of waves that enter the bay from the South China Sea.The estimates of net sediment drift derived from geomorphological, shoreline-change, and meteorological information are generally in good agreement. Sediment drift directions are predominantly to the northeast along Cavite, to the northwest along Manila and Bulacan, and to the north along Bataan. Wave refraction and eddy formation at the tip of the Cavite Spit cause southwestward sediment drift along the coast from Zapote to Kawit. Geomorphology indicates that onshore-offshore sediment transport is probably more important than alongshore transport along the coast fronting the tidal delta plain of northern Manila Bay. Disagreements between the geomorphic-derived and predicted net sediment drift directions may be due to interactions of wave-generated longshore currents with wind- and tide-generated currents.

Seasonal dynamics of bacterial biomass and production in a coastal arctic ecosystem: Franklin Bay, western Canadian Arctic

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Garneau, Marie-Ã. Ve; Roy, SéBastien; Lovejoy, Connie; Gratton, Yves; Vincent, Warwick F.

2008-07-01

The Canadian Arctic Shelf Exchange Study (CASES) included the overwintering deployment of a research platform in Franklin Bay (70°N, 126°W) and provided a unique seasonal record of bacterial dynamics in a coastal region of the Arctic Ocean. Our objectives were (1) to relate seasonal bacterial abundance (BA) and production (BP) to physico-chemical characteristics and (2) to quantify the annual bacterial carbon flux. BA was estimated by epifluorescence microscopy and BP was estimated from 3H-leucine and 3H-thymidine assays. Mean BA values for the water column ranged from 1.0 (December) to 6.8 × 105 cells mL-1 (July). Integral BP varied from 1 (February) to 80 mg C m-2 d-1 (July). During winter-spring, BP was uncorrelated with chlorophyll a (Chl a), but these variables were significantly correlated during summer-autumn (rs = 0.68, p winter, late winter-late spring, and summer. A baseline level of BB and BP was maintained throughout late winter-late spring despite the persistent cold and darkness, with irregular fluctuations that may be related to hydrodynamic events. During this period, BP rates were correlated with colored dissolved organic matter (CDOM) but not Chl a (rs BP.CDOM∣Chl a = 0.20, p < 0.05, N = 176). Annual BP was estimated as 6 g C m-2 a-1, implying a total BP of 4.8 × 1010 g C a-1 for the Franklin Bay region. These results show that bacterial processes continue throughout all seasons and make a large contribution to the total biological carbon flux in this coastal arctic ecosystem.

Correction: Ryan, J., et al. Application of the Hyperspectral Imager for the Coastal Ocean to Phytoplankton Ecology Studies in Monterey Bay, CA, USA. Remote Sens. 2014, 6, 1007–1025

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Marcos J. Montes

2015-10-01

Full Text Available Studies of phytoplankton ecology in Monterey Bay, CA, USA, using the Hyperspectral Imager for the Coastal Ocean (HICO and other satellite remote sensing and in-situ observations, were presented in [1]. [...

Toxic phytoplankton in San Francisco Bay

Science.gov (United States)

Rodgers, Kristine M.; Garrison, David L.; Cloern, James E.

1996-01-01

The Regional Monitoring Program (RMP) was conceived and designed to document the changing distribution and effects of trace substances in San Francisco Bay, with focus on toxic contaminants that have become enriched by human inputs. However, coastal ecosystems like San Francisco Bay also have potential sources of naturally-produced toxic substances that can disrupt food webs and, under extreme circumstances, become threats to public health. The most prevalent source of natural toxins is from blooms of algal species that can synthesize metabolites that are toxic to invertebrates or vertebrates. Although San Francisco Bay is nutrient-rich, it has so far apparently been immune from the epidemic of harmful algal blooms in the world’s nutrient-enriched coastal waters. This absence of acute harmful blooms does not imply that San Francisco Bay has unique features that preclude toxic blooms. No sampling program has been implemented to document the occurrence of toxin-producing algae in San Francisco Bay, so it is difficult to judge the likelihood of such events in the future. This issue is directly relevant to the goals of RMP because harmful species of phytoplankton have the potential to disrupt ecosystem processes that support animal populations, cause severe illness or death in humans, and confound the outcomes of toxicity bioassays such as those included in the RMP. Our purpose here is to utilize existing data on the phytoplankton community of San Francisco Bay to provide a provisional statement about the occurrence, distribution, and potential threats of harmful algae in this Estuary.

Numerical investigation of pollution transport and environmental improvement measures in a tidal bay based on a Lagrangian particle-tracking model

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En-jin Zhao

2018-01-01

Full Text Available In view of the severity of oceanic pollution, based on the finite volume coastal ocean model (FVCOM, a Lagrangian particle-tracking model was used to numerically investigate the coastal pollution transport and water exchange capability in Tangdao Bay, in China. The severe pollution in the bay was numerically simulated by releasing and tracking particles inside it. The simulation results demonstrate that the water exchange capability in the bay is very low. Once the bay has suffered pollution, a long period will be required before the environment can purify itself. In order to eliminate or at least reduce the pollution level, environmental improvement measures have been proposed to enhance the seawater exchange capability and speed up the water purification inside the bay. The study findings presented in this paper are believed to be instructive and useful for future environmental policy makers and it is also anticipated that the numerical model in this paper can serve as an effective technological tool to study many emerging coastal environment problems. Keywords: Particle-tracking, Water exchange capability, Lagrangian system, Coastal pollution, Tangdao bay, FVCOM

Study on the Coastline Change of Jiaozhou Bay Based on High Resolution Remote Sensing Image

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Zhu, H.; Xing, B.; Ni, S.; Wei, P.

2018-05-01

In recent years, with the rapid development of the Jiaozhou Bay area of Qingdao, the influence of human activities on the coastline of Jiaozhou Bay is becoming more and more serious. Based on the high resolution remote sensing image data of 10 periods from 2001 to 2017 in the Jiaozhou Bay area, and combined with the data of on-the-spot survey and expert knowledge, this paper have completed the interpretation and extraction of coastline data of each year, and analyzed the distribution, size, rate of change, and trend of the increase and decrease of the coastal area of Jiaozhou Bay in different time periods, combined with the economic construction and the marine hydrodynamic environment of the region to analyze the reasons for the change of the coastline of Jiaozhou Bay. The results show that the increase and reduction of the coastal area of Jiaozhou Bay was mainly affected by human activities such as sea reclamation and marine aquaculture, resulting in a gradual change in the rate of increase and decrease with human development. For coastal advance part,2001-2013, the average increase rate on the coastal area of Jiaozhou Bay was 2.30 km2/a, showing a trend of rapid growth, 2013-2017 the average increase rate of 0.53 km2/a, and the growth rate slowed down. For coastal retreat part, 2001-2013, the average decrease rate was 2.58 × 10-3 km2/a. 2013-2014, the decrease rate reached a peak value of 1.11 km2/a. 2014-2017, the average decrease rate was 0.14 km2/a. The decrease rate shows a trend of increasing first and then slowing down.

Observed seasonal variability of barrier layer in the Bay of Bengal

Digital Repository Service at National Institute of Oceanography (India)

Pankajakshan, T.; Muraleedharan, P.M.; Rao, R.R.; Somayajulu, Y.K.; Reddy, G.V.; Revichandran, C.

The observed formation of Barrier Layer (BL) and the seasonal variability of BL thickness (BLT) in the Bay of Bengal are examined utilizing the most comprehensive data set. Thick BL (~50m) first appears in the coastal region of the northeastern bay...

A strong CO2 sink enhanced by eutrophication in a tropical coastal embayment (Guanabara Bay, Rio de Janeiro, Brazil)

Science.gov (United States)

Cotovicz, L. C., Jr.; Knoppers, B. A.; Brandini, N.; Costa Santos, S. J.; Abril, G.

2015-10-01

In contrast to its small surface area, the coastal zone plays a disproportionate role in the global carbon cycle. Carbon production, transformation, emission and burial rates at the land-ocean interface are significant at the global scale but still poorly known, especially in tropical regions. Surface water pCO2 and ancillary parameters were monitored during nine field campaigns between April 2013 and April 2014 in Guanabara Bay, a tropical eutrophic to hypertrophic semi-enclosed estuarine embayment surrounded by the city of Rio de Janeiro, southeast Brazil. Water pCO2 varied between 22 and 3715 ppmv in the bay, showing spatial, diurnal and seasonal trends that mirrored those of dissolved oxygen (DO) and chlorophyll a (Chl a). Marked pCO2 undersaturation was prevalent in the shallow, confined and thermally stratified waters of the upper bay, whereas pCO2 oversaturation was restricted to sites close to the small river mouths and small sewage channels, which covered only 10 % of the bay's area. Substantial daily variations in pCO2 (up to 395 ppmv between dawn and dusk) were also registered and could be integrated temporally and spatially for the establishment of net diurnal, seasonal and annual CO2 fluxes. In contrast to other estuaries worldwide, Guanabara Bay behaved as a net sink of atmospheric CO2, a property enhanced by the concomitant effects of strong radiation intensity, thermal stratification, and high availability of nutrients, which promotes phytoplankton development and net autotrophy. The calculated CO2 fluxes for Guanabara Bay ranged between -9.6 and -18.3 mol C m-2 yr-1, of the same order of magnitude as the organic carbon burial and organic carbon inputs from the watershed. The positive and high net community production (52.1 mol C m-2 yr-1) confirms the high carbon production in the bay. This autotrophic metabolism is apparently enhanced by eutrophication. Our results show that global CO2 budgetary assertions still lack information on tropical

A large CO2 sink enhanced by eutrophication in a tropical coastal embayment (Guanabara Bay, Rio de Janeiro, Brazil)

Science.gov (United States)

Cotovicz, L. C., Jr.; Knoppers, B. A.; Brandini, N.; Costa Santos, S. J.; Abril, G.

2015-03-01

In contrast to its small surface area, the coastal zone plays a disproportionate role in the global carbon cycle. Carbon production, transformation, emission and burial rates at the land-ocean interface are still poorly known, especially in tropical regions. Surface water pCO2 and ancillary parameters were monitored during nine field campaigns between April 2013 and April 2014 in Guanabara Bay, a tropical eutrophic to hypertrophic semi-enclosed estuarine embayment surrounded by the city of Rio de Janeiro, SE-Brazil. Water pCO2 varied between 22 and 3715 ppmv in the Bay showing spatial, diurnal and seasonal trends that mirrored those of dissolved oxygen (DO) and Chlorophyll a (Chl a). Marked pCO2 undersaturation was prevalent in the shallow, confined and thermally stratified waters of the upper bay, whereas pCO2 oversaturation was restricted to sites close to the small river mouths and small sewage channels, which covered only 10% of the bay's area. Substantial daily variations in pCO2 (up to 395 ppmv between dawn and dusk) were also registered and could be integrated temporally and spatially for the establishment of net diurnal, seasonal and annual CO2 fluxes. In contrast to other estuaries worldwide, Guanabara Bay behaved as a net sink of atmospheric CO2, a property enhanced by the concomitant effects of strong radiation intensity, thermal stratification, and high availability of nutrients, which promotes phytoplankton development and net autotrophy. In the inner part of the bay, the calculated annual CO2 sink (-19.6 mol C m2 yr-1) matched the organic carbon burial in the sediments reported in the literature. The carbon sink and autotrophy of Guanabara Bay was driven by planktonic primary production promoted by eutrophication, and by its typology of marine embayment lacking the classical extended estuarine mixing zone, in contrast to river-dominated estuarine systems, which are generally net heterotrophic and CO2 emitters. Our results show that global CO2

Implementation of remote sensing data in research of coastal dynamics at the Baydaratskaya Bay, Kara Sea

Science.gov (United States)

Kuznetsov, D. E.; Belova, N.; Noskov, A.; Ogorodov, S.

2011-12-01

, detailed enough for preliminary analysis, free for significant part), Ikonos, QuickBird, and other modern high-resolution imagery. Georeferencing is taken from State topographic and bathymetric maps and high resolution imagery (corrected by field GPS survey where possible). All data are aligned and catalogued with ArcGIS. Corona and aerial images must be aligned thoroughly with use of high-resolution data as reference, placing control points on most stable topography (gully junctions, inter-lake channels, river heads), which are vectorized in advance. Shoreline is usually easily recognizable for both erosion and accumulation sections of the coast. Other distinct features include alongshore bars, thermokarst basins, deflation sites. Basing on above-mentioned analysis, coastal dynamics maps were created for time span long enough to ensure shore dynamics forecasts. For the coast of Baydaratskaya Bay, Kara Sea, the maps cover period from 1964 to 2009. Further steps include creation of shore classification and segmentation maps, which consider different features of coastal morphology, dynamics, and formation taken from both field investigations and remote sensing data analysis. This work was supported by Sustainable Arctic Coastal and Marine Technology (SACME) Project.

Spatial distribution of fallout 137Cs in the coastal marine environment of India

International Nuclear Information System (INIS)

Jha, S.K.; Gothankar, S.S.; Sartandel, S.; Pote, M.B.; Hemalatha, P.; Rajan, M.P.; Vidyasagar, D.; Indumati, S.P.; Shrivastava, R.; Puranik, V.D.

2012-01-01

The data on the fallout 137 Cs in the coastal marine environment assume significance in view of massive expansion of nuclear power plants in the Asia-Pacific region and to fulfill the benchmark study required to evaluate the possible impact of the Fukushima radioactive releases in the Asia-Pacific region. Measurements of 137 Cs in sea water, along with salinity and temperature, were carried out at 30 locations covering the coastal area of the Arabian Sea and the Bay of Bengal. For the present study the Indian coastal area is divided in three different regions. The 137 Cs concentration in sea water of the entire Indian coastal region varies from 0.30 to 1.25 Bq m −3 . The data obtained in the present study was compared with the North Indian Ocean data and it was observed that there is a 33% decrease in the Arabian Sea (region I), 50% in the high rainfall coastal area (region II) and 24% in the Bay of Bengal (region III). - Highlights: ► Benchmark value of 137 Cs in coastal environment of Arabian Sea and Bay of Bengal. ► International reference source of 137 Cs in coastal marine environment of India. ► In-situ pre-concentration technique for measurement of 137 Cs. ► Comparison of 137 Cs Indian coastal data with ASPAMARD.

Coastal seas as a context for science teaching: a lesson from Chesapeake Bay.

Science.gov (United States)

Bell, Wayne H; Fowler, Erin M; Stein, J Andrew

2003-01-01

space. The "salt wedge," picnocline, and anoxia are examined using graphics derived from data taken by researchers using "ScanFish," a towed instrument that samples temperature, salinity, and dissolved oxygen at a resolution of only a few meters vertically and horizontally. The seasonal dynamics of these parameters at a given location are interpreted using biweekly monitoring data obtained as part of the state-federal Chesapeake Bay Program. The influence of annual variations in freshwater input is examined using stream flow data from US. Geological Survey gauging stations. Satellite remote sensing images from the TOPEX/Poseidon project are used to show how El Niño and La Niña events in the mid-Pacific affect the Chesapeake Bay system via rainfall on its watershed. Finally, the life cycle of the blue crab (Callinectes sapidus) is presented to show how an estuarine organism has adapted to this truly unique and dynamic coastal environment.

Vibracore, Radiocarbon, Microfossil, and Grain-Size Data from Apalachicola Bay, Florida

Science.gov (United States)

Twichell, D.C.; Pendleton, E.A.; Poore, R.Z.; Osterman, L.E.; Kelso, K.W.

2009-01-01

In 2007, the U.S. Geological Survey collected 24 vibracores within Apalachicola Bay, Florida. The vibracores were collected by using a Rossfelder electric percussive (P-3) vibracore system during a cruise on the Research Vessel (R/V) G.K. Gilbert. Selection of the core sites was based on a geophysical survey that was conducted during 2005 and 2006 in collaboration with the National Oceanic and Atmospheric Administration's (NOAA) Coastal Services Center (CSC) and the Apalachicola Bay National Estuarine Research Reserve. This report contains the vibracore data logs, photographs, and core-derived data including grain-size analyses, radiocarbon ages, microfossil counts, and sedimentological interpretations. The long-term goal of this study is to provide maps, data, and assistance to the Apalachicola Bay National Estuarine Research Reserve in their effort to monitor and understand the geology and ecology of Apalachicola Bay Estuary. These data will inform coastal managers charged with the responsibility for resource preservation.

Coastal circulation and sediment dynamics in Pelekane and Kawaihae Bays, Hawaii--measurements of waves, currents, temperature, salinity, turbidity, and geochronology: November 2010--March 2011

Science.gov (United States)

Storlazzi, Curt D.; Field, Michael E.; Presto, M. Katherine; Swarzenski, Peter W.; Logan, Joshua B.; Reiss, Thomas E.; Elfers, Timothy C.; Cochran, Susan A.; Torresan, Michael E.; Chezar, Hank

2012-01-01

Coral reef communities on the Island of Hawaii have been heavily affected by the construction of Kawaihae Harbor in the 1950s and by subsequent changes in land use in the adjacent watershed. Sedimentation and other forms of land-based pollution have led to declines in water quality and coral reef health over the past two decades (Tissot, 1998). Erosion mitigation efforts are underway on land, and there is a need to evaluate the impact of these actions on the adjacent coastal ecosystem. The Kohala Center and Kohala Watershed Partnership was awarded $2.69 million from the National Oceanographic and Atmospheric Administration’s (NOAA) Restoration Center as part of the American Recovery and Reinvestment Act of 2009 to stabilize soil and improve land-use practices in the Pelekane Bay watershed. The grant allowed the Kohala Watershed Partnership to implement various upland watershed management activities to reduce land-based sources of pollution into Pelekane Bay. However, a number of questions must be answered in order to: (1) evaluate the effectiveness of the terrestrial watershed remediation efforts; (2) understand the potential of the local marine ecosystem to recover; and (3) understand the potential threat that existing mud deposits in the bay pose to adjacent, relatively pristine coral reef ecosystems. The goal of this experiment was to help address these questions and establish a framework to evaluate the success of the Kohala Watershed Partnership restoration efforts. This research program will also provide resource managers with information relevant to other watershed restoration efforts currently being planned in neighboring watersheds. This project involved an interdisciplinary team of coral reef biologists from the University of Hawaii Coral Reef Assessment and Monitoring Program, who focused on the impact of sedimentation on the biota of Pelekane Bay, and a team of geologists and oceanographers from the U.S. Geological Survey (USGS), who focused on the

Sediment Quality of the SW Coastal Laizhou Bay, Bohai Sea, China: A Comprehensive Assessment Based on the Analysis of Heavy Metals

Science.gov (United States)

Gao, Xuelu; Zhuang, Wen; Chen, Chen-Tung Arthur; Zhang, Yong

2015-01-01

Historically, the Bohai Sea is one of the most important fishing grounds in China. Yet, surrounded by one of the biggest economic rims of China, its ecological functions have been declining rapidly in recent two decades under the heavy anthropogenic impacts. The Laizhou Bay is the smallest one of the three main bays in the Bohai Sea. Owing to the rich brine deposits, chemical industries using brine as raw materials are booming in the southern coast of the Laizhou Bay, the scale of which ranks as the largest one in China. In order to monitor and assess the environmental quality, surface sediments were collected from the coastal waters of southwestern Laizhou Bay and the rivers it connects with during summer and autumn in 2012, and analyzed for heavy metals. Several widely adopted methods were used in the overall assessment of heavy metal pollution status and potential ecological risks in these sediments, and the data were analyzed to infer the main sources of the pollutants. The results showed that the remarkably high concentrations of heavy metals were almost all recorded in a small number of riverine sites. Cr, Cu, Ni and Zn were the main environmental threat according to the sediment quality guidelines. The marine area was generally in good condition with no or low risk from the studied metals and adverse effects on biota could hardly occur. Natural sources dominated the concentrations and distributions of Cu, Ni, Pb and Zn in the marine area. Our results indicated that heavy metal pollution was not a main cause of the ecological degradation of the Laizhou Bay at present. PMID:25816338

Sediment quality of the SW coastal Laizhou Bay, Bohai Sea, China: a comprehensive assessment based on the analysis of heavy metals.

Science.gov (United States)

Gao, Xuelu; Zhuang, Wen; Chen, Chen-Tung Arthur; Zhang, Yong

2015-01-01

Historically, the Bohai Sea is one of the most important fishing grounds in China. Yet, surrounded by one of the biggest economic rims of China, its ecological functions have been declining rapidly in recent two decades under the heavy anthropogenic impacts. The Laizhou Bay is the smallest one of the three main bays in the Bohai Sea. Owing to the rich brine deposits, chemical industries using brine as raw materials are booming in the southern coast of the Laizhou Bay, the scale of which ranks as the largest one in China. In order to monitor and assess the environmental quality, surface sediments were collected from the coastal waters of southwestern Laizhou Bay and the rivers it connects with during summer and autumn in 2012, and analyzed for heavy metals. Several widely adopted methods were used in the overall assessment of heavy metal pollution status and potential ecological risks in these sediments, and the data were analyzed to infer the main sources of the pollutants. The results showed that the remarkably high concentrations of heavy metals were almost all recorded in a small number of riverine sites. Cr, Cu, Ni and Zn were the main environmental threat according to the sediment quality guidelines. The marine area was generally in good condition with no or low risk from the studied metals and adverse effects on biota could hardly occur. Natural sources dominated the concentrations and distributions of Cu, Ni, Pb and Zn in the marine area. Our results indicated that heavy metal pollution was not a main cause of the ecological degradation of the Laizhou Bay at present.

Sediment quality of the SW coastal Laizhou Bay, Bohai Sea, China: a comprehensive assessment based on the analysis of heavy metals.

Directory of Open Access Journals (Sweden)

Xuelu Gao

Full Text Available Historically, the Bohai Sea is one of the most important fishing grounds in China. Yet, surrounded by one of the biggest economic rims of China, its ecological functions have been declining rapidly in recent two decades under the heavy anthropogenic impacts. The Laizhou Bay is the smallest one of the three main bays in the Bohai Sea. Owing to the rich brine deposits, chemical industries using brine as raw materials are booming in the southern coast of the Laizhou Bay, the scale of which ranks as the largest one in China. In order to monitor and assess the environmental quality, surface sediments were collected from the coastal waters of southwestern Laizhou Bay and the rivers it connects with during summer and autumn in 2012, and analyzed for heavy metals. Several widely adopted methods were used in the overall assessment of heavy metal pollution status and potential ecological risks in these sediments, and the data were analyzed to infer the main sources of the pollutants. The results showed that the remarkably high concentrations of heavy metals were almost all recorded in a small number of riverine sites. Cr, Cu, Ni and Zn were the main environmental threat according to the sediment quality guidelines. The marine area was generally in good condition with no or low risk from the studied metals and adverse effects on biota could hardly occur. Natural sources dominated the concentrations and distributions of Cu, Ni, Pb and Zn in the marine area. Our results indicated that heavy metal pollution was not a main cause of the ecological degradation of the Laizhou Bay at present.

Dissolved Organic Matter (DOM) Export from Watersheds to Coastal Oceans

Science.gov (United States)

Chen, R. F.; Gardner, G. B.; Peri, F.

2016-02-01

Dissolved organic matter (DOM) from terrestrial plants and soils is transported by surface waters and groundwaters to coastal ocean waters. Along the way, photochemical and biological degradation can remove DOM, and in situ processes such as phytoplankton leaching and sediment sources can add to the DOM in the river water. Wetlands, especially coastal wetlands can add significant amounts of DOM that is carried by rivers and is exported through estuaries to coastal systems. We will present observational data from a variety of coastal systems (San Francisco Bay, Boston Harbor, Chesapeake Bay, Hudson River, the Mississippi River, and a small salt marsh in the Gulf of Mexico). High resolution measurements of chromophoric dissolved organic matter (CDOM) can be correlated with dissolved organic carbon (DOC) so can be used to estimate DOC in specific systems and seasons. Gradients in CDOM/DOC combined with water fluxes can be used to estimate DOC fluxes from a variety of coastal watersheds to coastal systems. Influences of land use, system size, residence time, DOM quality, and photochemical and biological degradation will be discussed. The significance of coastal wetlands in the land-to-ocean export of DOC will be emphasized.

Geophysical mapping of oyster habitats in a shallow estuary; Apalachicola Bay, Florida

Science.gov (United States)

Twichell, David C.; Andrews, Brian D.; Edmiston, H. Lee; Stevenson, William R.

2007-01-01

This report presents high-resolution geophysical data, interpretive maps, and a preliminary discussion about the oyster habitat and estuary-floor geology within Apalachicola Bay, Florida (fig. 1). During two research cruises, conducted in 2005 and 2006, approximately 230 km² of the bay floor were surveyed using interferometric-bathymetry, sidescan-sonar, and chirp seismic-reflection techniques. The research was conducted as part of a cooperative program between the U.S. Geological Survey (USGS), the National Oceanic and Atmospheric Administration Coastal Services Center (CSC), and the Apalachicola Bay National Estuarine Research Reserve. The Apalachicola Bay National Estuarine Research Reserve was established in 1979 to provide opportunities for long-term monitoring and research to provide a basis for more informed coastal management decisions for this estuary. Apalachicola Bay is the largest oyster fishery in Florida (Whitfield and Beaumariage, 1977), and the primary objective of this program is to develop a suite of maps that define oyster habitat distribution and estuary-floor geology within the bay. The resulting maps will assist in effective management of oyster resources and provide a reference geologic framework for future scientific and applied research.

Essential coastal habitats for fish in the Baltic Sea

DEFF Research Database (Denmark)

Kraufvelin, Patrik; Pekcan-Hekim, Zeynep; Bergström, Ulf

2018-01-01

Many coastal and offshore fish species are highly dependent on specific habitat types for population maintenance. In the Baltic Sea, shallow productive habitats in the coastal zone such as wetlands, vegetated flads/lagoons and sheltered bays as well as more exposed rocky and sandy areas are utili...

Black and Brown Bear Activity at Selected Coastal Sites in Glacier Bay National Park and Preserve, Alaska: A Preliminary Assessment Using Noninvasive Procedures

Science.gov (United States)

Partridge, Steve; Smith, Tom; Lewis, Tania

2009-01-01

A number of efforts in recent years have sought to predict bear activity in various habitats to minimize human disturbance and bear/human conflicts. Alaskan coastal areas provide important foraging areas for bears (Ursus americanus and U. arctos), particularly following den emergence when there may be no snow-free foraging alternatives. Additionally, coastal areas provide important food items for bears throughout the year. Glacier Bay National Park and Preserve (GLBA) in southeastern Alaska has extensive coastal habitats, and the National Park Service (NPS) has been long interested in learning more about the use of these coastal habitats by bears because these same habitats receive extensive human use by park visitors, especially kayaking recreationists. This study provides insight regarding the nature and intensity of bear activity at selected coastal sites within GLBA. We achieved a clearer understanding of bear/habitat relationships within GLBA by analyzing bear activity data collected with remote cameras, bear sign mapping, scat collections, and genetic analysis of bear hair. Although we could not quantify actual levels of bear activity at study sites, agreement among measures of activity (for example, sign counts, DNA analysis, and video record) lends support to our qualitative site assessments. This work suggests that habitat evaluation, bear sign mapping, and periodic scat counts can provide a useful index of bear activity for sites of interest.

Multiple stressors threaten the imperiled coastal foundation species eelgrass (Zostera marina) in Chesapeake Bay, USA.

Science.gov (United States)

Lefcheck, Jonathan S; Wilcox, David J; Murphy, Rebecca R; Marion, Scott R; Orth, Robert J

2017-09-01

Interactions among global change stressors and their effects at large scales are often proposed, but seldom evaluated. This situation is primarily due to lack of comprehensive, sufficiently long-term, and spatially extensive datasets. Seagrasses, which provide nursery habitat, improve water quality, and constitute a globally important carbon sink, are among the most vulnerable habitats on the planet. Here, we unite 31 years of high-resolution aerial monitoring and water quality data to elucidate the patterns and drivers of eelgrass (Zostera marina) abundance in Chesapeake Bay, USA, one of the largest and most valuable estuaries in the world, with an unparalleled history of regulatory efforts. We show that eelgrass area has declined 29% in total since 1991, with wide-ranging and severe ecological and economic consequences. We go on to identify an interaction between decreasing water clarity and warming temperatures as the primary drivers of this trend. Declining clarity has gradually reduced eelgrass cover the past two decades, primarily in deeper beds where light is already limiting. In shallow beds, however, reduced visibility exacerbates the physiological stress of acute warming, leading to recent instances of decline approaching 80%. While degraded water quality has long been known to influence underwater grasses worldwide, we demonstrate a clear and rapidly emerging interaction with climate change. We highlight the urgent need to integrate a broader perspective into local water quality management, in the Chesapeake Bay and in the many other coastal systems facing similar stressors. © 2017 John Wiley & Sons Ltd.

GoM Coastal Biopsy Surveys - NRDA

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Small vessel surveys were conducted within estuarine and nearshore coastal waters of Barataria Bay, LA and Mississippi Sound, MS to collect tissue biopsy samples...

Bristol Bay, Alaska Subarea ESI: HABITATS (Habitats Polygons)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for submerged aquatic vegetation (SAV) in the Bristol Bay Subarea. The Subarea includes marine and coastal...

Mapping resilience not risk: Turning the tide in New York City and Jamaica Bay

Science.gov (United States)

Parris, A. S.; Sanderson, E. W.

2015-12-01

Resilience in urban coastal areas is affected by actions at multiple levels from individuals to community groups to city, state and federal governments. At any level, actions can be a response to immediate hazards (e.g. flooding of coastal homes) or long-term drivers of change (e.g. sea level rise). Jamaica Bay, a highly urbanized estuary within New York City, exemplifies the Nation's coastal zone challenges. Prior to Hurricane Sandy, city, state, and federal governments had made the estuary a major focal point for habitat restoration, improvements to public access and outdoor recreation, and sustainable development. Sandy caused the highest flood level in the recorded history of New York City, eventually claiming 44 lives and costing over $19 billion. Electrical system failure caused four of NYCs wastewater pollution control plants to shutdown, discharging untreated sewage into Jamaica Bay. The Sea Level Rise Tool for Sandy Recovery (the Tool), a flood mapping tool developed by several government agencies including FEMA, NYC, and the Executive Branch, integrated science from the National Flood Insurance Program and the New York City Panel on Climate Change (NPCC). While compound flooding hazards (stormwater plus coastal flooding) remain an important uncertainty, the Tool and subsequent NPCC mapping efforts provide sufficient evidence for science-based discourse around coastal flood risks in Jamaica Bay. But toward what outcome? Coastal flood risk reduction measures and other management actions are managed within existing regulatory frameworks. Disaster relief funds appropriated by Congress in the immediate aftermath of Sandy have provided critical resources to the Jamaica Bay region. However, the challenge now is to transition from the short-term response to long-term resilience planning, a challenge which requires new institutional capacity. This transition to resilience planning and implementation is not only critical in New York City, but in other coastal

Geophysical monitoring of coastal erosion and cliff retreat of ...

African Journals Online (AJOL)

Monitoring of the coastal zone is necessary to assess its vulnerability and help formulate coastal management plans. A predetermined stretch of beach along the northern rim of False Bay known locally as Monwabisi Beach was chosen to compare different monitoring techniques and from the data acquired, see if accurate ...

Coastal upwelling seasonality and variability of temperature and chlorophyll in a small coastal embayment

Science.gov (United States)

Walter, Ryan K.; Armenta, Kevin J.; Shearer, Brandon; Robbins, Ian; Steinbeck, John

2018-02-01

While the seasonality of wind-driven coastal upwelling in eastern boundary upwelling systems has long been established, many studies describe two distinct seasons (upwelling and non-upwelling), a generalized framework that does not capture details relevant to marine ecosystems. In this contribution, we present a more detailed description of the annual cycle and upwelling seasonality for an understudied location along the central California coast. Using both the mean monthly upwelling favorable wind stress and the monthly standard deviation, we define the following seasons (contiguous months) and a transitional period (non-contiguous months): "Winter Storms" season (Dec-Jan-Feb), "Upwelling Transition" period (Mar and Jun), "Peak Upwelling" season (Apr-May), "Upwelling Relaxation" season (Jul-Aug-Sep), and "Winter Transition" season (Oct-Nov). In order to describe the oceanic response to this upwelling wind seasonality, we take advantage of nearly a decade of full water-column measurements of temperature and chlorophyll made using an automated profiling system at the end of the California Polytechnic State University Pier in San Luis Obispo Bay, a small ( 2 km wide near study site) and shallow ( 10 m average bay depth) coastal embayment. Variability and average-year patterns are described inside the bay during the various upwelling seasons. Moreover, the role of the local coastline orientation and topography on bay dynamics is also assessed using long-term measurements collected outside of the bay. The formation of a seasonally variable upwelling shadow system and potential nearshore retention zone is discussed. The observations presented provide a framework on which to study interannual changes to the average-year seasonal cycle, assess the contribution of higher-frequency features to nearshore variability, and better predict dynamically and ecologically important events.

Coastal conduit in southwestern Hudson Bay (Canada) in summer: Rapid transit of freshwater and significant loss of colored dissolved organic matter

Science.gov (United States)

Granskog, Mats A.; MacDonald, Robie W.; Kuzyk, Zou Zou A.; Senneville, Simon; Mundy, Christopher-John; Barber, David G.; Stern, Gary A.; Saucier, Francois

2009-08-01

Distributions of freshwater (sea-ice melt and runoff) were investigated along inshore-offshore sections in southwestern Hudson Bay for fall conditions. Conductivity-temperature-density profiles and bottle samples collected for salinity, oxygen isotope (δ18O), and colored dissolved organic matter (CDOM) analyses were used to discriminate between contributions of river water (RW) and sea-ice melt (SIM). Stations had a fresh summer surface mixed layer 5-25 m thick overlying a cold subsurface layer indicative of the previous winter's polar mixed layer (PML). The fraction of RW decreased strongly with distance from shore, while the opposite was true for SIM. The majority of RW was constrained in a coastal domain within 100-150 km from shore, which, because of high alongshore velocities, accounts for the majority of freshwater and volume transports. On the basis of freshwater inventories and composition, brine and RW accumulate in the PML over winter because of ice formation and downward mixing. The summer surface circulation results in an annual net export of SIM from the region. Residence times for freshwater components in the southwestern sector of the bay, based on currents derived from a 3-D ocean model for Hudson Bay, are about 1-10 months, implying rapid transit of freshwater. Despite the short residence time for RW (1-3 months), CDOM is significantly photobleached and provides an unreliable tracer for RW. Photobleaching represents an important sink for dissolved organic carbon entering from rivers and could, in part, explain why Hudson Bay is only a minor sink for atmospheric CO2 in the open water season.

CO2 induced growth response in a diatom dominated phytoplankton community from SW Bay of Bengal coastal water

Science.gov (United States)

Biswas, Haimanti; Shaik, Aziz Ur Rahman; Bandyopadhyay, Debasmita; Chowdhury, Neha

2017-11-01

The ongoing increase in surface seawater CO2 level could potentially impact phytoplankton primary production in coastal waters; however, CO2 sensitivity studies on tropical coastal phytoplankton assemblages are rare. The present study investigated the interactive impacts of variable CO2 level, light and zinc (Zn) addition on the diatom dominated phytoplankton assemblages from the western coastal Bay of Bengal. Increased CO2 supply enhanced particulate organic matter (POC) production; a concomitant depletion in δ13CPOM values at elevated CO2 suggested increased CO2 diffusive influx inside the cell. Trace amount of Zn added under low CO2 level accelerated growth probably by accelerating Zn-Carbonic Anhydrase activity which helps in converting bicarbonate ion to CO2. Almost identical values of δ13CPOM in the low CO2 treated cells grown with and without Zn indicated a low discrimination between 13C and 12C probably due to bicarbonate uptake. These evidences collectively indicated the existence of the carbon concentration mechanisms (CCMs) at low CO2. A minimum growth rate was observed at low CO2 and light limited condition indicating light dependence of CCMs activity. Upon the increase of light and CO2 level, growth response was maximum. The cells grown in the low CO2 levels showed higher light stress (higher values of both diatoxanthin index and the ratio of photo-protective to light-harvesting pigments) that was alleviated by both increasing CO2 supply and Zn addition (probably by efficient light energy utilization in presence of adequate CO2). This is likely that the diatom dominated phytoplankton communities benefited from the increasing CO2 supply and thus may enhance primary production in response to any further increase in coastal water CO2 levels and can have large biogeochemical consequences in the study area.

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

Factors regulating early life history dispersal of Atlantic cod (Gadus morhua) from coastal Newfoundland.

Science.gov (United States)

Stanley, Ryan R E; deYoung, Brad; Snelgrove, Paul V R; Gregory, Robert S

2013-01-01

To understand coastal dispersal dynamics of Atlantic cod (Gadus morhua), we examined spatiotemporal egg and larval abundance patterns in coastal Newfoundland. In recent decades, Smith Sound, Trinity Bay has supported the largest known overwintering spawning aggregation of Atlantic cod in the region. We estimated spawning and dispersal characteristics for the Smith Sound-Trinity Bay system by fitting ichthyoplankton abundance data to environmentally-driven, simplified box models. Results show protracted spawning, with sharply increased egg production in early July, and limited dispersal from the Sound. The model for the entire spawning season indicates egg export from Smith Sound is 13%•day(-1) with a net mortality of 27%•day(-1). Eggs and larvae are consistently found in western Trinity Bay with little advection from the system. These patterns mirror particle tracking models that suggest residence times of 10-20 days, and circulation models indicating local gyres in Trinity Bay that act in concert with upwelling dynamics to retain eggs and larvae. Our results are among the first quantitative dispersal estimates from Smith Sound, linking this spawning stock to the adjacent coastal waters. These results illustrate the biophysical interplay regulating dispersal and connectivity originating from inshore spawning of coastal northwest Atlantic.

Factors regulating early life history dispersal of Atlantic cod (Gadus morhua from coastal Newfoundland.

Directory of Open Access Journals (Sweden)

Ryan R E Stanley

Full Text Available To understand coastal dispersal dynamics of Atlantic cod (Gadus morhua, we examined spatiotemporal egg and larval abundance patterns in coastal Newfoundland. In recent decades, Smith Sound, Trinity Bay has supported the largest known overwintering spawning aggregation of Atlantic cod in the region. We estimated spawning and dispersal characteristics for the Smith Sound-Trinity Bay system by fitting ichthyoplankton abundance data to environmentally-driven, simplified box models. Results show protracted spawning, with sharply increased egg production in early July, and limited dispersal from the Sound. The model for the entire spawning season indicates egg export from Smith Sound is 13%•day(-1 with a net mortality of 27%•day(-1. Eggs and larvae are consistently found in western Trinity Bay with little advection from the system. These patterns mirror particle tracking models that suggest residence times of 10-20 days, and circulation models indicating local gyres in Trinity Bay that act in concert with upwelling dynamics to retain eggs and larvae. Our results are among the first quantitative dispersal estimates from Smith Sound, linking this spawning stock to the adjacent coastal waters. These results illustrate the biophysical interplay regulating dispersal and connectivity originating from inshore spawning of coastal northwest Atlantic.

Kachemak Bay, Alaska 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. These integrated...

Effect of acidification on an Arctic phytoplankton community from Disko Bay, West Greenland

DEFF Research Database (Denmark)

Thoisen, Christina; Riisgaard, Karen; Lundholm, Nina

2015-01-01

. Our findings show that coastal phytoplankton from Disko Bay is naturally exposed to pH fluctuations exceeding the experimental pH range used in most ocean acidification studies. We emphasize that studies on ocean acidification should include in situ pH before assumptions on the effect of acidification...... on marine organisms can be made. KEY WORDS: Ocean acidification · Coastal · Arctic phytoplankton · Growth rate · pH · CO2 · DIC......ABSTRACT: Long-term measurements (i.e. months) of in situ pH have not previously been reported from the Arctic; this study shows fluctuations between pH 7.5 and 8.3 during the spring bloom 2012 in a coastal area of Disko Bay, West Greenland. The effect of acidification on phytoplankton from...

Identification of High Potential Bays for HABs Occurrence in Peninsular Malysia Using Palsar Remote Sensing Data

Science.gov (United States)

Pour, A. B.; Hashim, M.

2016-09-01

Increasing frequency, intensity, and geographic distribution of Harmful algal blooms (HABs) poses a serious threat to the coastal fish/shellfish aquaculture and fisheries in Malaysian bays. Rising in sea level, shoreline erosion, stresses on fisheries, population pressure, interference of land-use and lack of institutional capabilities for integrated management make major challenges. Recent investigations and satellite observations indicate HABs originated from specific coast that have favourable geographic, geomorphic and coastal geology conditions to bring the green macro algae from the coast offshore. Therefore, the identification of high HABs frequented bays using remote sensing and geology investigations in Malaysian waters is required to reduce future challenges in this unique case. This research implemented comprehensive geomorphic and coastal geology investigations combined with remote sensing digital image processing approach to identify Malaysian bays frequented with HABs occurrence in Malaysian waters territory. The landscape and geomorphological features of the Malaysian bays were constructed from the Phased Array type L-band Synthetic Aperture Radar (PALSAR) remote sensing satellite data combined with field observations and surveying. The samples for laboratory analysis were collected from the sediment stations with different distance across shorelines features and watersheds of the Johor Bahru estuary. This research identified that semi-enclosed bays such as Kuala Lumpur and Johor Bahru bays with connection to estuaries have high potential to be frequented with HABs occurrence.

IDENTIFICATION OF HIGH POTENTIAL BAYS FOR HABs OCCURRENCE IN PENINSULAR MALYSIA USING PALSAR REMOTE SENSING DATA

Directory of Open Access Journals (Sweden)

A. B. Pour

2016-09-01

Full Text Available Increasing frequency, intensity, and geographic distribution of Harmful algal blooms (HABs poses a serious threat to the coastal fish/shellfish aquaculture and fisheries in Malaysian bays. Rising in sea level, shoreline erosion, stresses on fisheries, population pressure, interference of land-use and lack of institutional capabilities for integrated management make major challenges. Recent investigations and satellite observations indicate HABs originated from specific coast that have favourable geographic, geomorphic and coastal geology conditions to bring the green macro algae from the coast offshore. Therefore, the identification of high HABs frequented bays using remote sensing and geology investigations in Malaysian waters is required to reduce future challenges in this unique case. This research implemented comprehensive geomorphic and coastal geology investigations combined with remote sensing digital image processing approach to identify Malaysian bays frequented with HABs occurrence in Malaysian waters territory. The landscape and geomorphological features of the Malaysian bays were constructed from the Phased Array type L-band Synthetic Aperture Radar (PALSAR remote sensing satellite data combined with field observations and surveying. The samples for laboratory analysis were collected from the sediment stations with different distance across shorelines features and watersheds of the Johor Bahru estuary. This research identified that semi-enclosed bays such as Kuala Lumpur and Johor Bahru bays with connection to estuaries have high potential to be frequented with HABs occurrence.

Detection and mapping of the iron ore occurrence in the sea floor sediments in the coastal zone of the Sepetiba Bay. Rio de Janeiro. Brasil

International Nuclear Information System (INIS)

Vieira, P.

2010-01-01

This work is about the detection and mapping of the iron occurrence in the sea floor sediments in the coastal zone of the Sepetiba Bay. Rio de Janeiro. Brasil. The results of geochemical analysis revealed that the area around the mangrove forest located near the Itacuruca channel, the perpendicular direction to the Muriqui Yacht Club channel and the immediate vicinity of the the Guaiba Island Terminal were respectively the areas of highest iron ore concentration

Padilla Bay: The Estuary Guide. Level 1. Publication No. 93-108.

Science.gov (United States)

Friesem, Judy

Padilla Bay National Estuarine Research Reserve in Washington is managed by the Washington State Department of Ecology, Shorelands and Coastal Zone management Program. This guide is designed for primary teachers to complement a visit to the reserve and is a useful resource to teach about estuaries, shorelands, and coastal resources. Activities are…

Organic carbon balance and net ecosystem metabolism in Chesapeake Bay

Science.gov (United States)

Kemp, W.M.; Smith, E.M.; Marvin-DiPasquale, M.; Boynton, W.R.

1997-01-01

some 6-fold higher than the sum of all physical carbon sinks. This general negative correspondence between I:P ratio and NEM, which occurred among Bay regions, was also evident in data available for organic C fluxes in other coastal ecosystems. An inverse relationship between NEM and P, postulated in a previous study, did not apply to Chesapeake Bay, and closer examination of available data revealed the importance of the loading ratio of DIN:TOC as a key control on coastal NEM. It is proposed here that the general global trend of coastal eutrophication will lead to increasing values of NEM in estuaries worldwide. The management implications of this trend are complex, involving both increased potential fisheries harvest and decreased demersal habitat.

The Chesapeake Bay bolide impact: a new view of coastal plain evolution

Science.gov (United States)

Poag, C. Wylie

1998-01-01

A spectacular geological event took place on the Atlantic margin of North America about 35 million years ago in the late part of the Eocene Epoch. Sea level was unusually high everywhere on Earth, and the ancient shoreline of the Virginia region was somewhere in the vicinity of where Richmond is today (fig. 1). Tropical rain forests covered the slopes of the Appalachians. To the east of a narrow coastal plain, a broad, lime (calcium carbonate)- covered continental shelf lay beneath the ocean. Suddenly, with an intense flash of light, that tranquil scene was transformed into a hellish cauldron of mass destruction. From the far reaches of space, a bolide (comet or asteroid), 3-5 kilometers in diameter, swooped through the Earth's atmosphere and blasted an enormous crater into the continental shelf. The crater is now approximately 200 km southeast of Washington, D.C., and is buried 300-500 meters beneath the southern part of Chesapeake Bay and the peninsulas of southeastern Virginia (fig. 1). The entire bolide event, from initial impact to the termination of breccia deposition, lasted only a few hours or days. The crater was then buried by additional sedimentary beds, which accumulated during the following 35 million years.

Seasonal variability in the surface sediments of Mobile Bay, Alabama, recorded by geochemistry and foraminifera, 2009–2010

Science.gov (United States)

Umberger, D.K.; Osterman, L.E.; Smith, C.G.; Frazier, J.; Richwine, K.A.

2012-01-01

A study was undertaken in order to document and quantify recent environmental change in Mobile Bay, Alabama. The study was part of the Northern Gulf of Mexico (NGOM) Ecosystem Change and Hazard Susceptibility project, a regional project funded by the Coastal and Marine Geology Program to understand how natural forcings and anthropogenic modifications influence coastal ecosystems and their susceptibility to coastal hazards. Mobile Bay is a large drowned-river estuary that has been modified significantly by humans to accommodate the Port of Mobile. Examples include repeated dredging of a large shipping channel down the central axis of the bay and construction of a causeway across the head of the bay and at the foot of the bayhead delta. In addition to modifications, the bay is also known to have episodic periods of low oxygen (hypoxia) that result in significant mortality to fish and benthic organisms (May, 1973). For this study a series of surface sediment samples were collected. Surface benthic foraminiferal and bulk geochemical data provide the modern baseline conditions of the bay and can be used as a reference to changing environmental parameters in the past (Osterman and Smith, in press) and into the future. This report archives data collected as part of the Mobile Bay Study that may be used in future environmental change studies.

Application of State of the Art Modeling Techniques to Predict Flooding and Waves for a Coastal Area within a Protected Bay

Directory of Open Access Journals (Sweden)

Malcolm L. Spaulding

2017-03-01

Full Text Available Flood Insurance Rate Maps (FIRMs are developed by the Federal Emergency Management Agency (FEMA to provide guidance in establishing the risk to structures and infrastructure from storm surge sand associated waves in the coastal zone. The maps are used by state agencies and municipalities to help guide coastal planning and establish the minimum elevation and construction standards for new or substantially improved structures. A summary of the methods used and a comparison with the results of 2013 FIRM mapping are presented for Warwick, Rhode Island (RI, a coastal community located within Narragansett Bay. Because of its location, Warwick is protected from significant coastal erosion and wave attacks, but is subject to surge amplification. Concerns surrounding the FEMA methods used in the 2013 FIRM analysis are put in context with the National Research Council’s (NRC 2009 review of the FEMA coastal mapping program. New mapping is then performed using state of the art, fully coupled surge and wave modeling, and data analysis methods, to address the NRC concerns. The new maps and methodologies are in compliance with FEMA regulations and guidelines. This new approach makes extensive use of the numerical modeling results from the recent US Army Corp of Engineers, North Atlantic Coast Comprehensive Study (NACCS, 2015. Revised flooding maps are presented and compared to the 2013 FIRM maps, to provide insight into the differences. The new maps highlight the importance of developing better estimates of surge dynamics and the advancement in nearshore mapping of waves in flood inundated areas by the use of state of the art, two-dimensional, wave transformation models.

Analysis of Suspended-Sediment Dynamics in Gulf of Mexico Estuaries Using MODIS/Terra 250-m Imagery

Science.gov (United States)

McCarthy, M. J.; Otis, D. B.; Muller-Karger, F. E.; Mendez-Lazaro, P.; Chen, F. R.

2016-02-01

Suspended sediments in coastal ecosystems reduce light penetration, degrade water quality, and inhibit primary production. In this study, a 15-year Moderate Resolution Imaging Spectroradiometer (MODIS/Terra) turbidity time-series was developed for use in the estuaries of the Gulf of Mexico (GOM). Remote-sensing reflectance (Rrs) at 645 nm and 250-m resolution was validated with in-situ turbidity measurements in these estuaries: Coastal Bend Bays (TX), Galveston Bay (TX), Barataria and Terrebonne Bays (LA), Mobile Bay (AL), Tampa Bay (FL), Sarasota Bay (FL), and Charlotte Harbor (FL). Mean values of turbidity over the time-series ranged from 2.5 NTU to over 10 NTU. Turbidity patterns exhibited seasonal cycles with peak values generally found during spring months, although there is considerable variability in the timing of peak turbidity. Episodes of elevated turbidity ranged from 6 episodes in Galveston Bay to 15 in Mobile Bay. The spatial extent of elevated turbidity within estuaries, frequency and duration of turbidity events, and potential driving factors behind episodes of elevated turbidity were also examined.

Fish assemblages in a coastal bay adjacent to a network of marine protected areas in southern Brazil

Directory of Open Access Journals (Sweden)

André Pereira Cattani

Full Text Available Abstract Baía Norte (North Bay in Santa Catarina State is considered a typical coastal bay and is surrounded by a network of Marine Protected Areas. The objectives of this study were to describe the composition of the demersal fish assemblage, identify seasonal and spatial structures on a fine scale and evaluate the role of habitat descriptors and abiotic variables affecting the fish assemblage structure. Seasonal samplings were conducted in 2005, using bottom trawls in six pre-established areas in Baía Norte in summer, fall, winter and spring. Simultaneously with each trawl, environmental data were collected with a multiparameter probe. Temporal and spatial differences in fish abundance were tested by a PERMANOVA. To illustratethe differences detected graphically we ran a canonical analysis of principal coordinates (CAP. The influence of environmental variables on the fish fauna was evaluated using a Distant Based Linear Model (DistLM with Akaike's information criterion (AIC. A total of 9,888 specimens, distributed in 27 families and 62 species, were collected. Citharichthys spilopterus was the most abundant species. PERMANOVA detected differences for abundance between seasons, areas and interaction among all the factors. The DISTLM selected temperature and pH. The results highlight seasonality as an important factor in the structuring of fish fauna of the study place.

Delineation of marsh types from Corpus Christi Bay, Texas, to Perdido Bay, Alabama, in 2010

Science.gov (United States)

Enwright, Nicholas M.; Hartley, Stephen B.; Couvillion, Brady R.; Michael G. Brasher,; Jenneke M. Visser,; Michael K. Mitchell,; Bart M. Ballard,; Mark W. Parr,; Barry C. Wilson,

2015-07-23

Coastal zone managers and researchers often require detailed information regarding emergent marsh vegetation types (that is, fresh, intermediate, brackish, and saline) for modeling habitat capacities and needs of marsh dependent taxa (such as waterfowl and alligator). Detailed information on the extent and distribution of emergent marsh vegetation types throughout the northern Gulf of Mexico coast has been historically unavailable. In response, the U.S. Geological Survey, in collaboration with the Gulf Coast Joint Venture, the University of Louisiana at Lafayette, Ducks Unlimited, Inc., and the Texas A&M University-Kingsville, produced a classification of emergent marsh vegetation types from Corpus Christi Bay, Texas, to Perdido Bay, Alabama.

Coastal Bend Texas Benthic Habitat Mapping Reprocessed DOQQ Aerial Imagery

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — In 2006 and 2007 the NOAA Office for Coastal Management purchased services to reprocess existing digital multi-spectral imagery (ADS-40) and create digital benthic...

Coastal Bend Texas Benthic Habitat - Lower Laguna Madre 2004 Geodatabase

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — In 2006 and 2007 the NOAA Office for Coastal Management purchased services to process existing digital multi-spectral imagery (ADS-40) and create digital benthic...

Coastal Bend Texas Benthic Habitat - Lower Laguna Madre 2004 Biotic

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — In 2006 and 2007 the NOAA Office for Coastal Management purchased services to process existing digital multi-spectral imagery (ADS-40) and create digital benthic...

Phytoplankton bloom dynamics in coastal ecosystems: A review with some general lessons from sustained investigation of San Francisco Bay, California

Science.gov (United States)

Cloern, James E.

1996-05-01

Phytoplankton blooms are prominent features of biological variability in shallow coastal ecosystems such as estuaries, lagoons, bays, and tidal rivers. Long-term observation and research in San Francisco Bay illustrates some patterns of phytoplankton spatial and temporal variability and the underlying mechanisms of this variability. Blooms are events of rapid production and accumulation of phytoplankton biomass that are usually responses to changing physical forcings originating in the coastal ocean (e.g., tides), the atmosphere (wind), or on the land surface (precipitation and river runoff). These physical forcings have different timescales of variability, so algal blooms can be short-term episodic events, recurrent seasonal phenomena, or rare events associated with exceptional climatic or hydrologic conditions. The biogeochemical role of phytoplankton primary production is to transform and incorporate reactive inorganic elements into organic forms, and these transformations are rapid and lead to measurable geochemical change during blooms. Examples include the depletion of inorganic nutrients (N, P, Si), supersaturation of oxygen and removal of carbon dioxide, shifts in the isotopic composition of reactive elements (C, N), production of climatically active trace gases (methyl bromide, dimethylsulfide), changes in the chemical form and toxicity of trace metals (As, Cd, Ni, Zn), changes in the biochemical composition and reactivity of the suspended particulate matter, and synthesis of organic matter required for the reproduction and growth of heterotrophs, including bacteria, zooplankton, and benthic consumer animals. Some classes of phytoplankton play special roles in the cycling of elements or synthesis of specific organic molecules, but we have only rudimentary understanding of the forces that select for and promote blooms of these species. Mounting evidence suggests that the natural cycles of bloom variability are being altered on a global scale by human

Estrogenic compound profiles in an urbanized industry-impacted coastal bay and potential risk assessment by pollution indices and multivariative statistical methods.

Science.gov (United States)

Wang, Zaosheng; Li, Rui; Wu, Fengchang; Feng, Chenglian; Ye, Chun; Yan, Changzhou

2017-01-15

The occurrence and distribution of target estrogenic compounds in a highly urbanized industry-impacted coastal bay were investigated, and contamination profiles were evaluated by estimating total estradiol equivalents (∑EEQs) and risk quotients (RQs). Phenolic compounds were the most abundant xenoestrogens, but seldom showed contribution to the ∑EEQs. The diethylstilbestrol (DES) and 17α-ethinylestradiol (EE2) were the major contributors followed by 17β-estradiol (E2) in comparison with a slight contribution from estrone (E1) and estriol (E3). Both ∑EEQs and RQs indicated likely adverse effects posed on resident organisms. Further, multivariate statistical method comprehensively revealed pollution status by visualized factor scores and identified multiple "hotspots" of estrogenic sources, demonstrating the presence of complex pollution risk gradients inside and particularly outside of bay area. Overall, this study favors the integrative utilization of pollution indices and factor analysis as powerful tool to scientifically diagnose the pollution characterization of human-derived chemicals for better management decisions in aquatic environments. Copyright © 2016 Elsevier Ltd. All rights reserved.

A Holocene progradation record from Okains Bay, Banks Peninsula, Canterbury, New Zealand

International Nuclear Information System (INIS)

Stephenson, W.; Shulmeister, J.

1999-01-01

Fifty-eight distinct ridges are preserved on the Holocene progradation plain in Okains Bay, Banks Peninsula, Canterbury. Of these, 48 represent beach berm and foredune complexes and the remaining 10 are transverse dune ridges. Periods of rapid coastal progradation are marked by multiple beach berm preservation, whereas intervening periods of lower sediment accumulation result in a stable coastline and transverse dune formation. Infilling of the bay began following sea-level stabilisation in the mid Holocene. The fill is dominantly fine sand, which is derived from sediment carried around Banks Peninsula in the Southland Current and washed into Okains Bay by wave action. Variations in the progradation rate are therefore proxy indicators of coastal erosion in the Canterbury Bight. We demonstrate that there is little progradational fill preserved between c. 6500 and 2000 yr BP. This implies significant changes in sediment delivery to the Southland Current within the last 2000 yr, which we attribute to increased coastal erosion in South Canterbury. We speculate that this increasing erosion resulted from increased wave energy regimes, which in turn may relate to increasing Southern Hemisphere seasonality following the precessional cycle. (author). 32 refs., 4 figs., 3 tabs

Tortuguero Bay [Puerto Rico] environmental studies

International Nuclear Information System (INIS)

Wood, E.D.; Youngbluth, M.J.; Nutt, M.E.; Yoshioka, P.; Canoy, M.J.

1975-01-01

Site selection surveys and environmental research studies of seven coastal sites in Puerto Rico for construction of power generating facilities were carried out. Data are presented on the physical, chemical, and geological parameters of the Tortuguero Bay site, and the ecological parameters of zooplankton, benthic invertebrates, plant and fish communities. (U.S.)

Southern Monterey Bay Littoral Cell CRSMP Sensitive Habitat 2008

Data.gov (United States)

California Natural Resource Agency — One of the most important functions of the southern Monterey Bay coastal system is its role as a habitat for a unique flora and fauna. The beaches are habitat for...

Southern Monterey Bay Littoral Cell CRSMP Sensitive Habitat 2008

Data.gov (United States)

California Department of Resources — One of the most important functions of the southern Monterey Bay coastal system is its role as a habitat for a unique flora and fauna. The beaches are habitat for...

Modeling Coastal Vulnerability through Space and Time.

Science.gov (United States)

Hopper, Thomas; Meixler, Marcia S

2016-01-01

Coastal ecosystems experience a wide range of stressors including wave forces, storm surge, sea-level rise, and anthropogenic modification and are thus vulnerable to erosion. Urban coastal ecosystems are especially important due to the large populations these limited ecosystems serve. However, few studies have addressed the issue of urban coastal vulnerability at the landscape scale with spatial data that are finely resolved. The purpose of this study was to model and map coastal vulnerability and the role of natural habitats in reducing vulnerability in Jamaica Bay, New York, in terms of nine coastal vulnerability metrics (relief, wave exposure, geomorphology, natural habitats, exposure, exposure with no habitat, habitat role, erodible shoreline, and surge) under past (1609), current (2015), and future (2080) scenarios using InVEST 3.2.0. We analyzed vulnerability results both spatially and across all time periods, by stakeholder (ownership) and by distance to damage from Hurricane Sandy. We found significant differences in vulnerability metrics between past, current and future scenarios for all nine metrics except relief and wave exposure. The marsh islands in the center of the bay are currently vulnerable. In the future, these islands will likely be inundated, placing additional areas of the shoreline increasingly at risk. Significant differences in vulnerability exist between stakeholders; the Breezy Point Cooperative and Gateway National Recreation Area had the largest erodible shoreline segments. Significant correlations exist for all vulnerability (exposure/surge) and storm damage combinations except for exposure and distance to artificial debris. Coastal protective features, ranging from storm surge barriers and levees to natural features (e.g. wetlands), have been promoted to decrease future flood risk to communities in coastal areas around the world. Our methods of combining coastal vulnerability results with additional data and across multiple time

Spatial distribution of dinoflagellates from the tropical coastal waters of the South Andaman, India: Implications for coastal pollution monitoring

Digital Repository Service at National Institute of Oceanography (India)

Narale, D.D.; Anil, A.C.

Dinoflagellate community structure from two semi-enclosed areas along the South Andaman region, India, was investigated to assess the anthropogenic impact on coastal water quality. At the densely inhabited Port Blair Bay, the dominance of mixotrophs...

Biomagnification and debromination of polybrominated diphenyl ethers in a coastal ecosystem in Tokyo Bay

Energy Technology Data Exchange (ETDEWEB)

Mizukawa, Kaoruko; Yamada, Toshiko [Laboratory of Organic Geochemistry, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509 (Japan); Matsuo, Hiroaki; Takeuchi, Ichiro [Department of Life Environment Conservation, Faculty of Agriculture, Ehime University, Tarumi 3-5-7, Matsuyama, Ehime 790-8566 (Japan); Tsuchiya, Kotaro [Faculty of Marine Science, Tokyo University of Marine Science and Technology, Konan 4-5-7, Minato-ku, Tokyo 108-8477 (Japan); Takada, Hideshige, E-mail: shige@cc.tuat.ac.jp [Laboratory of Organic Geochemistry, Tokyo University of Agriculture and Technology, Fuchu, Tokyo 183-8509 (Japan)

2013-04-01

By field sampling and laboratory experiments we compared the mechanisms by which polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) are biomagnified. We measured PBDEs and PCBs, together with stable carbon and nitrogen isotopes as an index of trophic level, in low-trophic-level organisms collected from a coastal area in Tokyo Bay. PBDEs were biomagnified to a lesser degree than PCBs. The more hydrophobic congeners of each were biomagnified more. However, the depletion of BDE congeners BDE99 and BDE153 from fish was suggested. To study congener-specific biotransformation of halogenated compounds, we conducted an in vitro experiment using hepatic microsomes of two species of fish and five BDE congeners (BDE47, 99, 100, 153, and 154) and five CB congeners with the same substitution positions as the PBDEs. BDE99 and 153 were partially debrominated, but BDE47 and 154 were not debrominated. This congener-specific debromination is consistent with the field results. Both in vitro and field results suggested selective debromination at the meta position. The CB congeners were not transformed in vitro. This result is also consistent with the field results, that PCBs were more biomagnified than PBDEs. We conclude that metabolizability is an important factor in the biomagnification of chemicals, but other factors must be responsible for the lower biomagnification of PBDEs in natural ecosystems. Highlights: ► PBDEs were less biomagnified than PCBs in low-trophic-level organisms in Tokyo Bay. ► Depletion of PBDE congeners BDE99 and BDE153 from fish was suggested. ► BDE99 and 153 were debrominated in in vitro experiment using hepatic microsomes of fish. ► BDE47, 100, and 154 as well as PCB congeners were not transformed in vitro. ► Both in vitro and field results suggested selective meta-protonation of PBDEs.

Bay-scale population structure in coastal Atlantic cod in Labrador and Newfoundland, Canada

DEFF Research Database (Denmark)

Ruzzante, D.E.; Wroblewski, J.S.; Taggart, C.T.

2000-01-01

Polymorphisms at five microsatellite DNA loci provide evidence that Atlantic cod Gadus morhua inhabiting Gilbert Bay, Labrador are genetically distinguishable from offshore cod on the north- east Newfoundland shelf and from inshore cod in Trinity Bay, Newfoundland. Antifreeze activity in the blood...... of population structure suggest that important barriers to gene flow exist among five components that include two inshore (Gilbert and Trinity Bay) and three offshore cod aggregations on the north-east Newfoundland Shelf and the Grand Bank. D-A and D-SW estimates of genetic distance that involve Gilbert Bay cod...

Coastal currents and mass transport of surface sediments over the shelf regions of Monterey Bay, California

Science.gov (United States)

Wolf, S.C.

1970-01-01

In Monterey Bay, the highest concentrations of medium and fine sands occur nearshore between ten and thirty fathoms. Silt and clay accumulate in greater depths. Contours of median diameter roughly parallel the isobaths. Fine-grained materials are supplied to the bay region from erosion of cliffs which partly surround Monterey Bay, from sediment laden river discharge, and from continual reworking of widespread Pleistocene and Recent sea floor sediments. These sediments in turn are picked up by coastal currents and distributed over the shelf regions by present day current regimes. Studies of bottom currents over the shelf regions and in Monterey Canyon have revealed patterns which vary with seasonal changes. Current patterns during August and September exhibit remarkable symmetry about the axis of Monterey Submarine Canyon. Central Shelf currents north and south of Monterey Canyon flowed northwest at an average rate of 0.2 knots and south at 0.3 knots respectively. On the North Shelf between January and March currents flowed east to southeast at 0.3-0.5 knots with mirror image patterns above the South Shelf during the same period. Irregular current flow in the canyon indicates a complex current structure with frequent shifts in counterclockwise and clockwise direction over very short periods of time. Bottom topography of the canyon complex often causes localization of canyon currents. One particular observation at a depth of 51 fathoms indicated up-canyon flow at a rate of 0.2 knots. Most of the observed currents are related to seasonal variations, upwelling, ocean swell patterns, and to changes in the California and Davidson currents. Changes in current regimes are reflected in the patterns of sediment distribution and transport. Sediment transport is chiefly parallel to the isobaths, particularly on the North and South Shelf regions. Complex dispersal patterns are observed near Monterey Canyon and Moss Landing Harbor jetties. Longshore currents move sediments

Southern Monterey Bay Littoral Cell CRSMP Proposed Receiver Site 2008

Data.gov (United States)

California Natural Resource Agency — Given the location of the critical areas of erosion and the need to avoid adverse impacts to local sensitive habitat, the Southern Monterey Bay Coastal RSM Plan...

Southern Monterey Bay Littoral Cell CRSMP Proposed Receiver Site 2008

Data.gov (United States)

California Department of Resources — Given the location of the critical areas of erosion and the need to avoid adverse impacts to local sensitive habitat, the Southern Monterey Bay Coastal RSM Plan...

Tampa Bay as a model estuary for examining the impact of human activities on biogeochemical processes: an introduction

Science.gov (United States)

Swarzenski, Peter W.; Baskaran, Mark; Henderson, Carl S.; Yates, Kim

2007-01-01

Tampa Bay is a shallow, Y-shaped coastal embayment that is located along the center of the Florida Platform – an expansive accumulation of Cretaceous–Tertiary shallow-water carbonates and evaporites that were periodically exposed during glacio–eustatic sea level fluctuations. As a consequence, extensive karstification likely had a controlling impact on the geologic evolution of Tampa Bay. Despite its large aerial size (∼ 1000 km2), Tampa Bay is relatively shallow (mean depth = 4 m) and its watershed (6700 km2) is among the smallest in the Gulf of Mexico. About 85% of all freshwater inflow (mean = 63 m3 s-1) to the bay is carried by four principal tributaries (Orlando et al., 1993). Groundwater makes up an important component of baseflow of these coastal streams and may also be important in delivering nutrients and other constituents to the bay proper by submarine groundwater discharge.

AFSC/ABL: Southeast Coastal Monitoring Project - CTD database

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Southeast Alaska Coastal Monitoring (SECM) project in Alaska was initiated in 1997 by the Auke Bay Laboratory, National Marine Fisheries Service, to study the...

Including granulometric sediment coastal data composition into the Black Sea GIS

Science.gov (United States)

Zhuk, Elena; Khaliulin, Alexey; Krylenko, Marina; Krylenko, Viacheslav; Zodiatis, George; Nikolaidis, Marios; Nikolaidis, Andreas

2017-09-01

The module structure of the Black Sea GIS allows the increasing of its functionality, including new data types and defining new procedures accessing them, their visualization and integration with existing data by their conjoint processing and representation. The Black Sea GIS is released as free software; Mapserver is used as a mapping service; MySQL DBMS works with relational data. A new additional feature provided, is the ability of including coastal data obtained in SB SIO RAS. The data represent granulometric composition of the Anapa bay-bar sediments. The Anapa bay-bar is an accumulative sand form (about 50 km long) located on the northwest Russian Black Sea coast. The entire bay-bar and especially its southern part with sand beaches 50-200 m wide is intensively used in recreation. This work is based on the results of field studies of 2010-2014 in the southern part of the Anapa bay-bar researched by scientists of the Shirshov Institute of Oceanology RAS. Since the shore under consideration has no clearly pronounced reference points, "virtual" points located within 1 km distance from each other were selected. Transversal profiles cross these points. The granulometric composition was studied along with 45 profiles. The samples taken in every profile were from the most characteristic morphological parts of the beach. In this study we used shoreline zone samples. Twenty one granule fractions (mm) were separated in the laboratory. The module which processes coastal data allows to select coastal data based on territory/region and granulometric sediment composition. Also, it allows to visualize coastal maps with user-selected features combined with other GIS data.

Effects of environmental variables on the survival of Phytophthora ramorum in bay laurel leaves

Science.gov (United States)

M.V. DiLeo; R.M. Bostock; D.M. Rizzo

2008-01-01

Bay laurel (Umbellularia californica (Hook. & Arn.) Nutt.) is the primary reservoir host of Phytophthora ramorum Werres, De Cock & Man n?t Veld in coastal California woodlands. Non-lethal foliar lesions on bay laurel trees support the majority of pathogen sporulation during the winter et season and appear to provide the...

Distribution of polycyclic aromatic hydrocarbons (PAHs) in sewage effluent, continental and coastal waters from the Northwestern Mediterrean Sea: Comparison between two contrasted catchment areas (Marseilles Bay and Vermeille coast)

Science.gov (United States)

Guigue, Catherine; Ferretto, Nicolas; Méjanelle, Laurence; Tedetti, Marc; Ghiglione, Jean-François; Goutx, Madeleine

2014-05-01

Polycyclic aromatic hydrocarbons (PAHs) were analysed from sewage treatment plant waters and surface waters collected in continental (rivers), harbour and off-shore marine sites from Marseilles Bay and Vermeille coastal areas between 2009 and 2013 (Northwestern Mediterranean Sea, France). After collection, water samples were first filtered on glass fiber filters, then PAHs from the dissolved phase were extracted using liquid-liquid or solid phase extraction (SPE) methods, while those from particles were treated according to Bligh and Dyer method. After a possible purification step, extracts were analysed by gas chromatography coupled to mass spectrometry (GC-MS). Regardless of the study area, dissolved and particulate PAH (18 parents + alkylated homologues) concentration averages were 150.2 ± 140.5 ng l-1and 39.4 ± 71.2 ng l-1, respectively. Interestingly, the concentration in dissolved PAHs was on average 3.8 higher than the concentration in particulate PAHs. In addition, a gradient of PAH concentrations was observed from coastal waters with the highest values in harbours and outlet sewage effluents and the lowest values in off-shore marine waters. Intermediate concentrations were recorded in continental waters. In the Marseilles Bay, dissolved PAH concentrations were significantly higher and associated to increased signatures of unburned and combusted fossil fuels, mainly from heating, during the cold period (November-April). In contrast, unburned petroleum signature dominated in the warm period (May-October), emphasizing the intense shipping traffic and urban/industrial activities occurring in one of the largest Mediterranean harbour and city. Conversely, in the Vermeille coastal waters, dissolved PAH concentrations were higher during the warm period when particulate PAHs displayed the lowest concentrations, suggesting a seasonal related partition between dissolved and particulate PAHs. In addition, in the Vermeille coastal waters, PAHs were dominated by

Using Seeds to Propagate and Restore Vallisneria americana Michaux (Wild Celery) in the Chesapeake Bay

Science.gov (United States)

2007-12-01

the capacity of the plants to elongate so that the leaves can reach closer to the water surface to gather adequate light for photosynthesis . When...transplant eelgrass (Zostera marina L.) in Chesapeake Bay and the Virginia Coastal Bays, In Proc. Conf. Seagrass Restoration: Success, Failure, and

Investigation of Spatial and Temporal Trends in Water Quality in Daya Bay, South China Sea

Science.gov (United States)

Wu, Mei-Lin; Wang, You-Shao; Dong, Jun-De; Sun, Cui-Ci; Wang, Yu-Tu; Sun, Fu-Lin; Cheng, Hao

2011-01-01

The objective is to identify the spatial and temporal variability of the hydrochemical quality of the water column in a subtropical coastal system, Daya Bay, China. Water samples were collected in four seasons at 12 monitoring sites. The Southeast Asian monsoons, northeasterly from October to the next April and southwesterly from May to September have also an important influence on water quality in Daya Bay. In the spatial pattern, two groups have been identified, with the help of multidimensional scaling analysis and cluster analysis. Cluster I consisted of the sites S3, S8, S10 and S11 in the west and north coastal parts of Daya Bay. Cluster I is mainly related to anthropogenic activities such as fish-farming. Cluster II consisted of the rest of the stations in the center, east and south parts of Daya Bay. Cluster II is mainly related to seawater exchange from South China Sea. PMID:21776234

Bristol Bay, Alaska Subarea ESI: M_MAMPT (Marine Mammal Points)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains sensitive biological resource data for Steller sea lions and seals in the Bristol Bay Subarea. The Subarea includes marine and coastal areas...

Meteorological research studies at Jervis Bay, Australia

International Nuclear Information System (INIS)

Clark, G.H.; Bendun, E.O.K.

1974-07-01

A climatological study of the winds and temperature from the Jervis Bay region which commenced in October 1970 has shown the presence of a coastal sea breeze and secondary bay breeze circulation system. In an attempt to define the influence of the Murray's Beach site on the local atmospheric dispersion, special smoke plume photography studies were conducted in the lower atmosphere. In June 1972 a meteorological acoustic sounding research programme was initiated at the Jervis Bay settlement. The aims of the research are to calibrate the sounder in terms of surface wind, turbulence and temperature measurements pertinent to a description of the lower atmospheric dispersion potential. Preliminary results on six months' data have shown encouraging correlations between the acoustic sounder patterns and particularly the wind direction turbulence traces. (author)

Plant diversity and biomass of Marudu bay mangroves in Malaysia

International Nuclear Information System (INIS)

Hanum, F.; Kudus, K.A.; Saari, N.S

2012-01-01

The mangroves of Marudu Bay in the state of Sabah is situated at the tip of Borneo Island, and at the southern limit of the Coral Triangle whose waters hold the highest diversity of corals, fish, molluscks, crustaceans and marine plant species in the world. The ecosystem shows a deterioration due to unsustainable fishing, pollution and encroachment, and these are impacting the Marudu Bay coastal communities economically. Fishing is the major economic activity here. Realising the importance of conserving the mangroves to uplift the socio-economic livelihood of the coastal community, a resource inventory of the mangroves and its productivity study were carried out. A total of 16 plant species in 12 genera and 9 families were identified. It was also found that 0.7 ha is capable of capturing all the species in the mangrove forest. The mangrove forests of Marudu Bay are dominated by Rhizopora apiculata and R. mucronata. The highest Importance Value index (IVI) was given by Rhizophora mucronata. Total Above Ground Biomass (TAGB) for 1-ha of mangrove forest in Marudu Bay was estimated to be 98.4 t/ha. It was found in other parallel studies that the mangroves of Marudu Bay are productive ecosystems that provide valuable habitats, nurseries and spawning grounds for various commercially important species of fish and invertebrates such as shrimp besides many species of wildlife. The mangroves at Marudu Bay are not only aesthetically attractive but provide opportunities for ecotourism activities that can be undertaken by the local community inhabiting the area to uplift their meagre income, These activities include mangrove cruising, recreational fishing, educational tourism and mangrove honey production, amongst others. This way, the degradation of the mangrove in Marudu Bay can be halted and reversed. (author)

California State Waters Map Series: offshore of Half Moon Bay, California

Science.gov (United States)

Cochrane, Guy R.; Dartnell, Peter; Greene, H. Gary; Johnson, Samuel Y.; Golden, Nadine E.; Hartwell, Stephen R.; Dieter, Bryan E.; Manson, Michael W.; Sliter, Ray W.; Ross, Stephanie L.; Watt, Janet T.; Endris, Charles A.; Kvitek, Rikk G.; Phillips, Eleyne L.; Erdey, Mercedes D.; Chin, John L.; Bretz, Carrie K.

2014-01-01

compression related to right-lateral strike-slip movement along the San Gregorio Fault Zone. The lowest elevation coincides with the deepest part of Half Moon Bay; the terrace surface rises both to the north and to the south. Uplift in this map area has resulted in relatively shallow water depths within California’s State Waters and, thus, little accommodation space for sediment accumulation. Sediment is observed in the shelter of Half Moon Bay and on the outer half of the California’s State Waters shelf. Sediment in the area is mobile, often forming dunes and sand waves. A westward bend in the San Andreas Fault Zone, southeast of the map area, coupled with right-lateral movement along the Seal Cove Fault, which comes ashore in Pillar Point Harbor, has resulted in the folding and uplifting of sedimentary rocks of the Purisima Formation in the offshore. Differential erosion of these folded and faulted layers of the Purisima Formation has exposed the parallel curved-rock ridges that are visible on the seafloor from the headland at Pillar Point. During the winter, strong North Pacific storms generate large, long-period waves that shoal and break over this bedrock reef at the world-famous surfing location known as Mavericks. The Offshore of Half Moon Bay map area lies within the cold-temperate biogeographic zone that is called either the “Oregonian province” or the “northern California ecoregion.” This biogeographic province is maintained by the long-term stability of the southward-flowing California Current, an eastern limb of the North Pacific subtropical gyre that flows from Oregon to Baja California. At its midpoint off central California, the California Current transports subarctic surface (0–500 m deep) waters southward, about 150 to 1,300 km from shore. Seasonal northwesterly winds that are, in part, responsible for the California Current, generate coastal upwelling. The south end of the Oregonian province is at Point Conception (about 365 km south of the map

Net-zooplankton abundance and biomass from Annaba Bay (SW Mediterranean Sea under estuarine influences

Directory of Open Access Journals (Sweden)

M. OUNISSI

2016-07-01

Full Text Available Zooplankton samples were collected in Annaba Bay (Algeria from January 2009-March 2011 at three coastal sites differently affected by estuarine plumes and external currents. Aim of this survey was to analyze zooplankton composition, abundance and biomass and compare the results with previous studies to reveal possible populations and environmental changes. The mean zooplankton abundance varied between 1,200-6,000 ind. m-3 and biomass 6.70-25.70 mg DW m-3, according to the site. Copepods constituted the main fraction of zooplankton community, and Oithona similis and Paracalanus indicus successively dominated during autumn-winter and spring-summer. The dinoflagellate Noctiluca scintillans was one of the major zooplankton components, and developed high numbers during February-April, becoming common in neritic and coastal regions. The singularity of the zooplankton from Annaba Bay is the prevalence of P. indicus throughout the entire bay and the decrease in Acartia discaudata and A. clausi (with respect to previous years, possibly replaced by A. negligens. Additionally, Oithona nana abundance markedly decreased with the large development of O. similis. Annaba Bay also differs from other similar Mediterranean coastal areas by the large development of Centropages ponticus populations during the warm period. Among the identified copepod species, the alien species Pseudodiaptomus australiensis and P. arabicus are reported for the first time in the Mediterranean Sea. The occurrence of copepodid V stages of P. australiensis suggests that this species survives and reproduces in Annaba Bay, but so far without developing an abundant population.

Two-Dimensional Hydrodynamic Simulation of Surface-Water Flow and Transport to Florida Bay through the Southern Inland and Coastal Systems (SICS)

Science.gov (United States)

Swain, Eric D.; Wolfert, Melinda A.; Bales, Jerad D.; Goodwin, Carl R.

2004-01-01

Successful restoration of the southern Florida ecosystem requires extensive knowledge of the physical characteristics and hydrologic processes controlling water flow and transport of constituents through extremely low-gradient freshwater marshes, shallow mangrove-fringed coastal creeks and tidal embayments, and near-shore marine waters. A sound, physically based numerical model can provide simulations of the differing hydrologic conditions that might result from various ecosystem restoration scenarios. Because hydrology and ecology are closely linked in southern Florida, hydrologic model results also can be used by ecologists to evaluate the degree of ecosystem restoration that could be achieved for various hydrologic conditions. A robust proven model, SWIFT2D, (Surface-Water Integrated Flow and Transport in Two Dimensions), was modified to simulate Southern Inland and Coastal Systems (SICS) hydrodynamics and transport conditions. Modifications include improvements to evapotranspiration and rainfall calculation and to the algorithms that describe flow through coastal creeks. Techniques used in this model should be applicable to other similar low-gradient marsh settings in southern Florida and elsewhere. Numerous investigations were conducted within the SICS area of southeastern Everglades National Park and northeastern Florida Bay to provide data and parameter values for model development and testing. The U.S. Geological Survey and the National Park Service supported investigations for quantification of evapotranspiration, vegetative resistance to flow, wind-induced flow, land elevations, vegetation classifications, salinity conditions, exchange of ground and surface waters, and flow and transport in coastal creeks and embayments. The good agreement that was achieved between measured and simulated water levels, flows, and salinities through minimal adjustment of empirical coefficients indicates that hydrologic processes within the SICS area are represented properly

Trace metals in coastal sediments of Costa Rica

International Nuclear Information System (INIS)

Garcia Cespedes, J.; Acuna Gonzalez, J.; Vargas Zamora, J.A.

2004-01-01

Marine sediment samples from four coastal ecosystems in Costa Rica were taken between the years 2000-2002 and their iron, lead, copper and zinc concentrations were determined by the atomic absorption technique with flame or graphite furnace. In the Pacific coast, Culebra Bay (Papagayo Gulf), Gulf of Nicoya, and Golfito Bay (Dulce Gulf), were selected as representative sites, and Moin Bay, at the Caribbean coast. Mean metal concentrations for all ecosystems followed the same pattern: Fe> Zn> Cu> Pb. No temporal pattern was found for any metal. Iron and copper mean concentrations were higher in Golfito Bay (5.8% and 87 μg / g, respectively) and lower in Moin Bay (3.4% and 52 μg / g, respectively). Zinc mean concentration was also higher in Golfito Bay (96 μg / g), but lower in Culebra Bay (66 μg / g). Lead mean concentration was higher in Moin Bay (6.4 μg / g) and lower in Culebra Bay (3.0 μg / g). Lead highest concentrations occurred in the Caribbean and in Golfito Bay, and for the rest of the elements the maximum values were found in Golfito Bay. On the basis of data obtained in this work, Culebra Bay was considered a relatively unpolluted location; Golfito Bay was more contaminated, and Moin Bay and the Gulf of Nicoya showed an intermediate condition. (Author) [es

15 CFR Appendix A to Subpart M of... - Monterey Bay National Marine Sanctuary Boundary Coordinates

Science.gov (United States)

2010-01-01

... 15 Commerce and Foreign Trade 3 2010-01-01 2010-01-01 false Monterey Bay National Marine Sanctuary... OF COMMERCE OCEAN AND COASTAL RESOURCE MANAGEMENT NATIONAL MARINE SANCTUARY PROGRAM REGULATIONS Monterey Bay National Marine Sanctuary Pt. 922, Subpt. M, App. A Appendix A to Subpart M of Part 922...

Seasonal variation of early diagenesis and greenhouse gas production in coastal sediments of Cadiz Bay: Influence of anthropogenic activities

Science.gov (United States)

Burgos, Macarena; Ortega, Teodora; Bohórquez, Julio; Corzo, Alfonso; Rabouille, Christophe; Forja, Jesús M.

2018-01-01

Greenhouse gas production in coastal sediments is closely associated with the early diagenesis processes of organic matter and nutrients. Discharges from anthropogenic activities, particularly agriculture, fish farming and waste-water treatment plants supply large amounts of organic matter and inorganic nutrients that affect mineralization processes. Three coastal systems of Cadiz Bay (SW Spain) (Guadalete River, Rio San Pedro Creek and Sancti Petri Channel) were chosen to determine the seasonal variation of organic matter mineralization. Two sampling stations were selected in each system; one in the outer part, close to the bay, and another more inland, close to a discharge point of effluent related to anthropogenic activities. Seasonal variation revealed that metabolic reactions were driven by the annual change of temperature in the outer station of the systems. In contrast, these reactions depended on the amount of organic matter reaching the sediments in the outermost part of the systems, which was higher during winter. Oxygen is consumed in the first 0.5 cm indicating that suboxic and anoxic processes, such as denitrification, sulfate reduction and methanogenesis are important in these sediments. Sulfate reduction seems to account for most of the mineralization of organic matter at the marine stations, while methanogenesis is the main pathway at the sole freshwater station of this study, located inside the estuary of the Guadalete River, because of the lack of sulfate as electron acceptor. Results point to denitrification being the principal process of N2O formation. Diffusive fluxes varied between 2.6 and 160 mmol m-2 d-1 for dissolved inorganic carbon (DIC); 0.9 and 164.3 mmol m-2 d-1 for TA; 0.8 and 17.4 μmol m-2 d-1 for N2O; and 0.1 μmol and 13.1 mmol m-2 d-1 for CH4, indicating that these sediments act as a source of greenhouse gases to the water column.

Composition and temporal patterns of larval fish communities in Chesapeake and Delaware Bays

Directory of Open Access Journals (Sweden)

Filipe Ribeiro

2015-11-01

Full Text Available Comparing larval fish assemblages in different estuaries provides insights about the coastal distribution of larval populations, larval transport, and adult spawning locations (Ribeiro et al. 2015. We simultaneously compared the larval fish assemblages entering two Middle Atlantic Bight (MAB estuaries (Delaware Bay and Chesapeake Bay, USA through weekly sampling from 2007 to 2009. In total, 43 taxa (32 families and 36 taxa (24 families were collected in Delaware and Chesapeake Bays, respectively. Mean taxonomic diversity, mean richness, and evenness were generally lower in Delaware Bay. Communities of both bays were dominated by Anchoa spp., Gobiosoma spp., Micropogonias undulatus, and Brevoortia tyrannus; Paralichthys spp. was more abundant in Delaware Bay and Microgobius thalassinus was more abundant in Chesapeake Bay. Inter-annual variation in the larval fish communities was low at both sites, with a relatively consistent composition across years, but strong seasonal (intra-annual variation in species composition occurred in both bays. Two groups were identified in Chesapeake Bay: a ‘winter’ group dominated by shelf-spawned species (e.g. M. undulatus and a ‘summer’ group comprising obligate estuarine species and coastal species (e.g. Gobiosoma spp. and Cynoscion regalis, respectively. In Delaware Bay, 4 groups were identified: a ‘summer’ group of mainly obligate estuarine fishes (e.g. Menidia sp. being replaced by a ‘fall’ group (e.g. Ctenogobius boleosoma and Gobionellus oceanicus; ‘winter’ and ‘spring’ groups were dominated by shelf-spawned (e.g. M. undulatus and Paralichthys spp. and obligate estuarine species (e.g. Leiostomus xanthurus and Pseudopleuronectes americanus, respectively. This study demonstrates that inexpensive and simultaneous sampling in different estuaries provides important insights into the variability in community structure of fish assemblages at large spatial scales.

THE INNOVATIVE POLICY OPTIONS FOR COASTAL FISHERIES ECONOMIC DEVELOPMENT: A CASE OF KWANDANG BAY COASTAL ECOSYSTEM

Directory of Open Access Journals (Sweden)

Noel Taylor Moore

2017-07-01

Full Text Available Socio-environmental problems, such as climate change, pollution and habitat destruction, present serious challenges for fisheries economic development. The integration of interventions or investments within a coastal marine ecosystem, a defined spatial area, is considered important in the economic development of local communities leading to the planned outcomes of livelihoods, food security and conservation The coastal marine ecosystem, is the provider of products and services to the local economy adjacent to the ecosystem where the benefit flows, within that area, are interconnected. The roles of science, technology and innovation (STI are an integral part of these multi-dimensional interventions. Hence the need for an integrated approach for these interventions by government and/or through donor funded projects to enhance economic development of coastal communities. The policy framework proposed is therefore an STI perspective of the links between these intervention and investment options, based on a ‘fisheries economic development Hub’ (Hub and discussed using the multi-level perspective (MLP. The policy innovation proposal suggests an implementation strategy of a pilot project and analyses the selection and implications of a potential Indonesian site for the application of the Hub. This paper aims to introduce the MLP into the framework of coastal community-based fisheries economic development.   Key words: policy innovation. coastal marine ecosystem, fisheries economic development Hub, value chains, multi-level perspective (MLP

Influence of El Niño and Indian Ocean Dipole on sea level variability in the Bay of Bengal

Science.gov (United States)

Sreenivas, P.; Gnanaseelan, C.; Prasad, K. V. S. R.

2012-01-01

Zonally oscillating seasonal equatorial winds generate pairs of upwelling and downwelling Kelvin waves in the Equatorial Indian Ocean, which then advance in to the coastal Bay of Bengal. The first (second) equatorial upwelling Kelvin wave has its origin in the western (eastern) basin, whereas the downwelling Kelvin waves originate in the central basin. The observed interannual variability of these Kelvin waves is highly governed by the associated zonal wind changes in the central and eastern equatorial Indian Ocean during the anomalous years. The second downwelling (upwelling) Kelvin wave is absent (weak) during El Niño (La Niña) years, whereas the second upwelling Kelvin wave strengthened during El Niño years both in the equatorial Indian Ocean and Bay of Bengal. The large scale off equatorial Rossby waves occasionally feedback the equatorial Kelvin waves, which then strengthen the Bay of Bengal coastal Kelvin waves. The coastal Kelvin waves and the associated radiated Rossby waves from east play a dominant role in the mesoscale eddy generation in Bay of Bengal. The analysis of cyclogenesis characteristics in the bay over the past 65 years revealed that the active (suppressed) phases of cyclogenesis are coinciding with the downwelling (upwelling) planetary waves which influence the cyclone heat potential by altering the thermocline depth.

Biological and geochemical data along Indian Point, Vermilion Bay, Louisiana

Science.gov (United States)

Richwine, Kathryn A.; Marot, Marci E.; Smith, Christopher G.; Osterman, Lisa E.; Adams, C. Scott

2015-09-14

Scientists from the U.S. Geological Survey, St. Petersburg Coastal and Marine Science Center collected shallow sediment cores and surface samples from a coastal salt marsh environment next to Vermilion Bay in southwest Louisiana in January 2013. The sampling was part of a larger USGS study to gather data for assessing environmental changes over the past 150 years. The objective of the study was to expand upon the historical context of sea level and storms affecting coastal systems and how these systems might change under persistent or varying conditions. The data from this report add to a regional environmental change database that aids with the continuing effort to understand the evolution of coastal systems.

Northeast Guanabara Bay and coastal plain Holocene sedimentary evolution (Brazil: A contribution

Directory of Open Access Journals (Sweden)

Rodrigo Coutinho Abuchacra

2017-02-01

Full Text Available Sedimentological and radiocarbon investigations are part of an ongoing research on the Bay-head delta of northeast Guanabara Bay, Rio de Janeiro State. Sediment accumulation indicates that the Holocene infill of the bay-head delta started around 8.2 kyr BP and was not in pace with the eustatic sea-level rise. Sediment accumulation was faster during the transgressive phase (0.56 cm.yr-1. However, during the regressive phase, progradation driven by base-level fall was predominant over vertical sediment accumulation (0.02 cm.yr-1. Based on coring, three sedimentary units were defined: fluvial sands (U1, estuarine deposits (U2 and fluvial mud (U3.

Ground Penetrating Radar (GPR) facies delineated shallow sedimentary records along a recently prograding coastal barrier adjoining the Bay of Bengal: Paradeep, Odisha, India

Science.gov (United States)

Layek, M. K.; Sengupta, P.; Mukherjee, A.

2017-12-01

Sea-level fluctuations, triggered by progradation of beach or marine regression, can be of various time-scales. The fluctuating history of a shoreline along a coastal barrier can be identified from the sedimentary features of accretion or erosion. The necessity of the understanding of the complex barrier dynamics and subsurface along the Paradeep coast (in the state of Odisha, India), adjacent to the Bay of Bengal, has been growing since the number of the harbor industrial projects and the inhabitants of this major port city of India increases. In this study area, high resolution ground penetrating radar (GPR) survey and its interpretation by GPR facies analysis, which considers the pattern/set of reflected electromagnetic signals, has proved to be a useful method for shallow-subsurface (up to 8 m) imaging. In order to perform this task, a GPR system with 200 MHZ antenna was employed to survey along (17 profiles) and across (21 profiles) the microtidal coastal barrier of Paradeep. The shapes and sizes of the accretional and erosional features like beach-ridge deposits, washover deposits, channel-and-fill, and scour-and-fill are delineated on the radargram after processing by Radan7® software. The internal geometry of the beach ridge is mapped accurately after the radar facies analysis which suggests the longshore drift of sediments from the nearby river mouths of Mahanadi, Devi and their tributaries. This GPR facies analysis revealed the existence of two types of palaeo-tidal channels of the study area - (a) larger channels which are perpendicular to the shoreline having channel width of about 400 m with maximum depth of 4.5 m from the surface and (b) smaller channels (width up to 60 m) which flow parallel to the shoreline. In case of Paradeep coastal barrier, seaward-dipping beach progradational facies is positioned within oblique erosional surfaces (13°-36°) below the horizontal erosional surface or facies boundary. This lead to delineate the cycles of erosion

Hydrodynamics and water quality models applied to Sepetiba Bay

Science.gov (United States)

Cunha, Cynara de L. da N.; Rosman, Paulo C. C.; Ferreira, Aldo Pacheco; Carlos do Nascimento Monteiro, Teófilo

2006-10-01

A coupled hydrodynamic and water quality model is used to simulate the pollution in Sepetiba Bay due to sewage effluent. Sepetiba Bay has a complicated geometry and bottom topography, and is located on the Brazilian coast near Rio de Janeiro. In the simulation, the dissolved oxygen (DO) concentration and biochemical oxygen demand (BOD) are used as indicators for the presence of organic matter in the body of water, and as parameters for evaluating the environmental pollution of the eastern part of Sepetiba Bay. Effluent sources in the model are taken from DO and BOD field measurements. The simulation results are consistent with field observations and demonstrate that the model has been correctly calibrated. The model is suitable for evaluating the environmental impact of sewage effluent on Sepetiba Bay from river inflows, assessing the feasibility of different treatment schemes, and developing specific monitoring activities. This approach has general applicability for environmental assessment of complicated coastal bays.

Coastal processes study at Ocean Beach, San Francisco, CA: summary of data collection 2004-2006

Science.gov (United States)

Barnard, Patrick L.; Eshleman, Jodi; Erikson, Li H.; Hanes, Daniel M.

2007-01-01

Ocean Beach in San Francisco, California, contains a persistent erosional section in the shadow of the San Francisco ebb tidal delta and south of Sloat Boulevard that threatens valuable public infrastructure as well as the safe recreational use of the beach. Coastal managers have been discussing potential mediation measures for over a decade, with little scientific research available to aid in decision making. The United States Geological Survey (USGS) initiated the Ocean Beach Coastal Processes Study in April 2004 to provide the scientific knowledge necessary for coastal managers to make informed management decisions. This study integrates a wide range of field data collection and numerical modeling techniques to document nearshore sediment transport processes at the mouth of San Francisco Bay, with emphasis on how these processes relate to erosion at Ocean Beach. The Ocean Beach Coastal Processes Study is the first comprehensive study of coastal processes at the mouth of San Francisco Bay.

Eddy-induced cross-shelf export of high Chl-a coastal waters in the SE Bay of Biscay

KAUST Repository

Rubio, Anna

2017-12-08

Different remote sensing data were combined to characterise a winter anticyclonic eddy in the southeastern Bay of Biscay and to infer its effects on cross-shelf exchanges, in a period when typical along shelf-slope currents depict a cyclonic pattern. While the joint analysis of available satellite data (infrared, visible and altimetry) permitted the characterisation and tracking of the anticyclone properties and path, data from a coastal high-frequency radar system enabled a quantitative analysis of the surface cross-shelf transports associated with this anticyclone. The warm core anticyclone had a diameter of around 50km, maximum azimuthal velocities near 50cms−1 and a relative vorticity of up to −0.45f. The eddy generation occurred after the relaxation of a cyclonic wind-driven current regime over the shelf-slope; then, the eddy remained stationary for several weeks until it started to drift northwards along the shelf break. The surface signature of this eddy was observed by means of high-frequency radar data for 20 consecutive days, providing a unique opportunity to characterise and quantify, from a Lagrangian perspective, the associated transport and its effect on the Chl-a surface distribution. We observed the presence of mesoscale structures with similar characteristics in the area during different winters within the period 2011–2014. Our results suggest that the eddy-induced recurrent cross-shelf export is an effective mechanism for the expansion of coastal productive waters into the adjacent oligotrophic ocean basin.

Soils and Vegetation of the Khaipudyr Bay Coast of the Barents Sea

Science.gov (United States)

Shamrikova, E. V.; Deneva, S. V.; Panyukov, A. N.; Kubik, O. S.

2018-04-01

Soils and vegetation of the coastal zone of the Khaipudyr Bay of the Barents Sea have been examined and compared with analogous objects in the Karelian coastal zone of the White Sea. The environmental conditions of these two areas are somewhat different: the climate of the Khaipudyr Bay coast is more severe, and the seawater salinity is higher (32-33‰ in the Khaipudyr Bay and 25-26‰ in the White Sea). The soil cover patterns of both regions are highly variable. Salt-affected marsh soils (Tidalic Fluvisols) are widespread. The complicated mesotopography includes high geomorphic positions that are not affected by tidal water. Under these conditions, zonal factors of pedogenesis predominate and lead to the development of Cryic Folic Histosols and Histic Reductaquic Cryosols. On low marshes, the concentrations of soluble Ca2+, K+ + Na+, Cl-, and SO2- 4 ions in the soils of the Khaipudyr Bay coast are two to four times higher than those in the analogous soils of Karelian coast. Cluster analysis of a number of soil characteristics allows separation of three soils groups: soils of low marshes, soils of middle-high marshes, and soils of higher positions developing under the impact of zonal factors together with the aerial transfer and deposition of seawater drops. The corresponding plant communities are represented by coastal sedge cenoses, forb-grassy halophytic cenoses, and zonal cenoses of hypoarctic tundra. It is argued that the grouping of marsh soils in the new substantivegenetic classification system of Russian soils requires further elaboration.

Some Challenges of an “Upside Down” Nitrogen Budget – Science and Management in Greenwich Bay, RI (USA)

Science.gov (United States)

When nutrients impact estuarine water quality, scientists and managers instinctively focus on quantifying and controlling land-based sources. However, in Greenwich Bay, RI, the estuary opens onto a larger and more intensively fertilized coastal water body (Narragansett Bay). Prev...

Submerged karst landforms observed by multibeam bathymetric survey in Nagura Bay, Ishigaki Island, southwestern Japan

Science.gov (United States)

Kan, Hironobu; Urata, Kensaku; Nagao, Masayuki; Hori, Nobuyuki; Fujita, Kazuhiko; Yokoyama, Yusuke; Nakashima, Yosuke; Ohashi, Tomoya; Goto, Kazuhisa; Suzuki, Atsushi

2015-01-01

Submerged tropical karst features were discovered in Nagura Bay on Ishigaki Island in the southern Ryukyu Islands, Japan. The coastal seafloor at depths shallower than ~ 130 m has been subjected to repeated and alternating subaerial erosion and sedimentation during periods of Quaternary sea-level lowstands. We conducted a broadband multibeam survey in the central area of Nagura Bay (1.85 × 2.7 km) and visualized the high-resolution bathymetric results over a depth range of 1.6-58.5 m. Various types of humid tropical karst landforms were found to coexist within the bay, including fluviokarst, doline karst, cockpit karst, polygonal karst, uvalas, and mega-dolines. Although these submerged karst landforms are covered by thick postglacial reef and reef sediments, their shapes and sizes are distinct from those associated with coral reef geomorphology. The submerged landscape of Nagura Bay likely formed during multiple glacial and interglacial periods. According to our bathymetric results and the aerial photographs of the coastal area, this submerged karst landscape appears to have developed throughout Nagura Bay (i.e., over an area of approximately 6 × 5 km) and represents the largest submerged karst in Japan.

Channel Shallowing as Mitigation of Coastal Flooding

Directory of Open Access Journals (Sweden)

Philip M. Orton

2015-07-01

Full Text Available Here, we demonstrate that reductions in the depth of inlets or estuary channels can be used to reduce or prevent coastal flooding. A validated hydrodynamic model of Jamaica Bay, New York City (NYC, is used to test nature-based adaptation measures in ameliorating flooding for NYC's two largest historical coastal flood events. In addition to control runs with modern bathymetry, three altered landscape scenarios are tested: (1 increasing the area of wetlands to their 1879 footprint and bathymetry, but leaving deep shipping channels unaltered; (2 shallowing all areas deeper than 2 m in the bay to be 2 m below Mean Low Water; (3 shallowing only the narrowest part of the inlet to the bay. These three scenarios are deliberately extreme and designed to evaluate the leverage each approach exerts on water levels. They result in peak water level reductions of 0.3%, 15%, and 6.8% for Hurricane Sandy, and 2.4%, 46% and 30% for the Category-3 hurricane of 1821, respectively (bay-wide averages. These results suggest that shallowing can provide greater flood protection than wetland restoration, and it is particularly effective at reducing "fast-pulse" storm surges that rise and fall quickly over several hours, like that of the 1821 storm. Nonetheless, the goal of flood mitigation must be weighed against economic, navigation, and ecological needs, and practical concerns such as the availability of sediment.

Coastal Bend Texas Benthic Habitat - Lower Laguna Madre (NODC Accession 0070784)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — In 2006 and 2007 the NOAA Coastal Services Center purchased services to process existing digital multi-spectral imagery (ADS-40) and create digital benthic habitat...

Concentrations of some elements in the coastal sea sediments. Bays with marinas

International Nuclear Information System (INIS)

Obhodas, J.; Kutle, A.; Valkovic, V.

2006-01-01

Surface sediments and sediment cores from two bays in the Adriatic sea (Punat Bay and Soline Bay, Croatia) have been analyzed for a number of elements, in particular: Ti, V, Mn, Fe, Cu, Zn, As and Pb, by using XRF. Maps of elemental distribution in surface sediments show increased concentrations for some elements present in antifouling paints (Cu, Zn, Pb) near the service areas in the villages or marinas. Core profiles for these elements were used to evaluate the environmental impact of newly constructed marinas. Source partition indicates the influence of other sources located in near by villages. The critical factor in these considerations was shown to be water exchange with the open sea. (author)

Assessment of the content, structure, and source of soil dissolved organic matter in the coastal wetlands of Jiaozhou Bay, China

Science.gov (United States)

Xi, Min; Zi, Yuanyuan; Wang, Qinggai; Wang, Sen; Cui, Guolu; Kong, Fanlong

2018-02-01

The contents and the spectral analysis of dissolved organic matter (DOM) in four typical wetlands, such as naked tidal, suaeda salsa, reed and spartina, were conducted to investigate the content, structure, and source of DOM in coastal wetland soil. The soil samples were obtained from Jiaozhou Bay in January, April, July, and October of 2014. Results showed that the DOM contents in soil of four typical wetland were in order of spartina wetland > naked tidal > suaeda salsa wetland > reed wetland in horizontal direction, and decreased with the increase of soil depth on vertical section. In addition, the DOM contents changed with the seasons, in order of spring > summer > autumn > winter. The structural characteristics of DOM in Jiaozhou Bay wetland, such as aromaticity, hydrophobicity, molecular weight, polymerization degree of benzene ring carbon frame structure and so on were in order of spartina wetland > naked tidal > suaeda salsa wetland > reed wetland in the horizontal direction. On the vertical direction, they showed a decreasing trend with the increase of soil depth. The results of three dimensional fluorescence spectra and fluorescence spectrum parameters (FI, HIX, and BIX) indicated that the DOM in Jiaozhou Bay was mainly derived from the biological activities. The contents and structure of DOM had certain relevance, but the contents and source as well as the structure and source of DOM had no significant correlation. The external pollution including domestic sewage, industrial wastewater, and aquaculture sewage affected the correlation among the content, structure and source of DOM by influencing the percentage of non-fluorescent substance in DOM and disturbing the determination of protein-like fluorescence.

Hydrographic features of the coastal waters of Kakinada

Digital Repository Service at National Institute of Oceanography (India)

Rao, B.P.; RamaRaju, V.S.

The physical characteristics of coastal waters - temperature, salinity and currents at the surface and subsurface levels - off Kakinada in the Bay of Bengal at 4 stations (bottom depth 5, 12, 22 and 42 m) along 17 degrees N latitude during January...

Radiotracer studies for coastal zone management

International Nuclear Information System (INIS)

Hughes, C.; Kluss, T.; Airey, P.

2001-01-01

Coastal engineers and coastal zone managers increasingly rely on numerical models of fluid, sediment and contaminant dynamics. These are used to underpin coastal structure design and to predict environmental response to specific events such as storms or pollutant spills, and gradual changes such as sea-level rise or changes in bathymetry. Radiotracer techniques can be used to provide dynamic data on the movement of a specific patch of water, sediment or pollutant over time, which can be compared with model predictions. Two case studies are presented where radiotracer studies were used to improve confidence in numerical models of: (1) 2D hydrodynamics and sediment transport at the Port of Songkhla, Thailand; and (2) 3D hydrodynamics and algal bloom transport in Manila Bay, Philippines

North Inlet-Winyah Bay National Estuarine Research Reserve's (NERR) Estuarine Water Quality Data for the North Inlet and Winyah Bay Estuaries, Georgetown, South Carolina: 1993-2002

Data.gov (United States)

Baruch Institute for Marine and Coastal Sciences, Univ of South Carolina — The North Inlet Estuary and the adjacent lower northeastern section of the Winyah Bay Estuary were designated as part of the National Estuarine Research Reserve...

Distribution, enrichment and sources of thallium in the surface sediments of the southwestern coastal Laizhou Bay, Bohai Sea.

Science.gov (United States)

Zhuang, Wen; Gao, Xuelu

2015-07-15

The concentrations of thallium (Tl) in the surface sediments of the southwestern coastal Laizhou Bay and the rivers it connects were determined. In riverine sediments, the Tl concentrations ranged from 0.34 to 0.76 μg g(-1) in summer; in autumn, the corresponding data were 0.35-1.08 μg g(-1). In marine sediments, the Tl concentrations ranged from 0.36 to 0.58 μg g(-1) in summer; and from 0.30 to 0.56 μg g(-1) in autumn. The grain size, Al and Fe oxides were major factors affecting Tl distribution. Tl in the surface sediments of the studied area was mainly from the natural input with the non-natural input as a subsidiary source. The low concentrations of Tl made it hard to cause potential negative environmental effects in this area. Copyright © 2015 Elsevier Ltd. All rights reserved.

Bromide in some coastal and oceanic waters of India

Digital Repository Service at National Institute of Oceanography (India)

DeSouza, F.P.; Dalal, V.N.K.

Bromide concentration and bromide/chlorinity ratio are estimated in coastal waters of Goa, Minicoy Lagoon, Western Arabian Sea and Western Bay of Bengal. The influence of precipitation and river runoff on bromide and bromide/chlorinity ratio...

Coastal Zone Color Scanner data of rich coastal waters

Science.gov (United States)

Wrigley, R. C.; Klooster, S. A.

1983-01-01

Comparisons of chlorophyll concentrations and diffuse attenuation coefficients measured from ships off the central California coast were made with satellite derived estimates of the same parameters using data from the Coastal Zone Color Scanner. Very high chlorophyll concentrations were encountered in Monterey Bay. Although lower chlorophyll values acquired off Pt. Sur agreed satisfactorily with the satellite data, the high chlorophyll values departed markedly from agreement. Two possible causes for the disagreement are suggested. Comparison of diffuse attenuation coefficients from the same data sets showed closer agreement.

Ocean currents structuring the mesozooplankton in the Gulf of Mannar and the Palk Bay, southeast coast of India

Digital Repository Service at National Institute of Oceanography (India)

Jagadeesan, L.; Jyothibabu, R.; Anjusha, A.; Mohan, A.P.; Madhu, N.V.; Muraleedharan, K.R.; Sudheesh, K.

for the observed variance in copepod distribution. In general, the copepod community in the Gulf of Mannar was composed both of coastal and offshore species whereas, coastal species largely inhabited the Palk Bay. This kind of a study depicting zooplankton...

An economically viable alternative to coastal discharge of produced water

International Nuclear Information System (INIS)

D'Unger, C.V.; Carr, R.S.; Chapman, D.C.

1993-01-01

The discharge of produced waters to coastal estuaries has been common practice on the Texas coast for many years as these discharges are currently exempt from NPDES permitting. A study of the active produced water discharges in Nueces Bay, Texas revealed that all eight effluents were highly toxic as determined by the sea urchin (Arbacia punctulata) fertilization and embryological development assays. An alternative to discharging produced water into coastal estuaries is the use of disposal wells. Inactive wells can be converted to produced water disposal wells. Production records for the Nueces Bay, Texas area reveal that 52% of the gas wells produce less than 100 mcf/d and 50% of the oil wells produce less than 10 b/d. Using conservative estimates, the cost of converting an inactive well to a disposal well was calculated to be $31,500 which could be paid out by a gas well producing as little as 100 mcf/d in 26 months using only 50% of the well's profit. Combining multiple leases to a single disposal well would reduce proportionately the cost to each operation. This study has demonstrated that economically viable disposal options could be achieved in the Nueces Bay area through the imaginative and cooperative formation of produced water disposal ventures. This same model could be applied to produced water discharges in other coastal areas

Fluorescence and absorption properties of chromophoric dissolved organic matter (CDOM) in coastal surface waters of the Northwestern Mediterranean Sea (Bay of Marseilles, France)

Science.gov (United States)

Para, J.; Coble, P. G.; Charrière, B.; Tedetti, M.; Fontana, C.; Sempéré, R.

2010-07-01

Seawater samples were collected in surface waters (2 and 5 m depths) of the Bay of Marseilles (Northwestern Mediterranean Sea; 5°17'30'' E, 43°14'30'' N) during one year from November 2007 to December 2008 and studied for total organic carbon (TOC) as well as chromophoric dissolved organic matter (CDOM) optical properties (absorbance and fluorescence). The annual mean value of surface CDOM absorption coefficient at 350 nm [aCDOM(350)] was very low (0.10 ± 0.02 m-1) with in comparison to values usually found in coastal waters, and no significant seasonal trend in aCDOM(350) could be determined. By contrast, the spectral slope of CDOM absorption (SCDOM) was significantly higher (0.023 ± 0.003 nm-1) in summer than in fall and winter periods (0.017 ± 0.002 nm-1), reflecting either CDOM photobleaching or production in surface waters during stratified sunny periods. The CDOM fluorescence, assessed through excitation emission matrices (EEMs), was dominated by protein-like component (peak T; 1.30-21.94 QSU) and marine humic-like component (peak M; 0.55-5.82 QSU), while terrestrial humic-like fluorescence (peak C; 0.34-2.99 QSU) remained very low. This reflected a dominance of relatively fresh material from biological origin within the CDOM fluorescent pool. At the end of summer, surface CDOM fluorescence was very low and strongly blue shifted, reinforcing the hypothesis of CDOM photobleaching. Our results suggested that unusual Rhône River plume eastward intrusion events may reach Marseilles Bay within 2-3 days and induce local phytoplankton blooms and subsequent fluorescent CDOM production (peaks M and T) without adding terrestrial fluorescence signatures (peak C). Besides Rhône River plumes, mixing events of the entire water column injected humic (peaks C and M) CDOM from the bottom into the surface and thus appeared also as an important source of CDOM in surface waters of the Marseilles Bay. Therefore, the assessment of CDOM optical properties, within the

77 FR 52701 - Board on Coastal Engineering Research

Science.gov (United States)

2012-08-30

... Environment and Human Health, and panel presentations dealing with Challenges to Ports and Navigation and Challenges to Beaches and Coastal Risk. Presentations dealing with Challenges to Ports and Navigation include Strategic Environmental Issues in Southeastern Dredging Operations; Mobile Bay Sediment Management Program...

Distribution of biologic, anthropogenic, and volcanic constituents as a proxy for sediment transport in the San Francisco Bay Coastal System

Science.gov (United States)

McGann, Mary; Erikson, Li H.; Wan, Elmira; Powell, Charles; Maddocks, Rosalie F.; Barnard, P.L.; Jaffee, B.E.; Schoellhamer, D.H.

2013-01-01

Although conventional sediment parameters (mean grain size, sorting, and skewness) and provenance have typically been used to infer sediment transport pathways, most freshwater, brackish, and marine environments are also characterized by abundant sediment constituents of biological, and possibly anthropogenic and volcanic, origin that can provide additional insight into local sedimentary processes. The biota will be spatially distributed according to its response to environmental parameters such as water temperature, salinity, dissolved oxygen, organic carbon content, grain size, and intensity of currents and tidal flow, whereas the presence of anthropogenic and volcanic constituents will reflect proximity to source areas and whether they are fluvially- or aerially-transported. Because each of these constituents have a unique environmental signature, they are a more precise proxy for that source area than the conventional sedimentary process indicators. This San Francisco Bay Coastal System study demonstrates that by applying a multi-proxy approach, the primary sites of sediment transport can be identified. Many of these sites are far from where the constituents originated, showing that sediment transport is widespread in the region. Although not often used, identifying and interpreting the distribution of naturally-occurring and allochthonous biologic, anthropogenic, and volcanic sediment constituents is a powerful tool to aid in the investigation of sediment transport pathways in other coastal systems.

Coastal Planning for Sustainable Maritime Management

Science.gov (United States)

Hakim, F.; Santoso, E. B.; Supriharjo, R.

2017-08-01

The Kendari Bay has a unique asset as a tourist attraction for the residents of the city of Kendari. The coastal area with all its potential like as a green open space, mangrove forests, the play area, is still a main destination to attract visitors. The function of Kendari Bay area as a tourist attraction makes this area as a place that has potential as a center of the economic vibrant and social interaction. Unfortunately, the arrangement of the area has not been done so that the integrated development of the region is not optimal. Therefore, it is important to promote a concept of area development as a tourist destination of coastal areas in order to improve function of the area. The concept of the coastal development area of Kendari Bay as tourist areas is formulated by the development criteria that influence to capable of attracting tourists. The criteria is formulated by the factors that play a role in the development of tourist areas, further exploration by qualitative descriptive analysis based on the information respondents. Fixation of the results of the criteria development was done with descriptive analysis assessed based on theoretically references through literature and regulations regarding the criteria for the development of tourism. To formulating the concept of tourism development used qualitative descriptive analysis technique with validation using triangulation techniques. The concept of tourism development based on the potential of the region is divided into three zones, namely area development of the core zone, direct supporting zone and indirect supporting zone. The macro spatial concept is necessary for the development of the area through the improvement of accessibility to tourist attraction, while the micro spatial concept includes improvements and additions to the activity in each zone to provide the convenience facilities for the tourists.

Transport processes near coastal ocean outfalls

Science.gov (United States)

Noble, M.A.; Sherwood, C.R.; Lee, Hooi-Ling; Xu, Jie; Dartnell, P.; Robertson, G.; Martini, M.

2001-01-01

The central Southern California Bight is an urbanized coastal ocean where complex topography and largescale atmospheric and oceanographic forcing has led to numerous sediment-distribution patterns. Two large embayments, Santa Monica and San Pedro Bays, are connected by the short, very narrow shelf off the Palos Verdes peninsula. Ocean-sewage outfalls are located in the middle of Santa Monica Bay, on the Palos Verdes shelf and at the southeastern edge of San Pedro Bay. In 1992, the US Geological Survey, together with allied agencies, began a series of programs to determine the dominant processes that transport sediment and associated pollutants near the three ocean outfalls. As part of these programs, arrays of instrumented moorings that monitor currents, waves, water clarity, water density and collect resuspended materials were deployed on the continental shelf and slope information was also collected on the sediment and contaminant distributions in the region. The data and models developed for the Palos Verdes shelf suggest that the large reservoir of DDT/DDE in the coastal ocean sediments will continue to be exhumed and transported along the shelf for a long time. On the Santa Monica shelf, very large internal waves, or bores, are generated at the shelf break. The near-bottom currents associated with these waves sweep sediments and the associated contaminants from the shelf onto the continental slope. A new program underway on the San Pedro shelf will determine if water and contaminants from a nearby ocean outfall are transported to the local beaches by coastal ocean processes. The large variety of processes found that transport sediments and contaminants in this small region of the continental margin suggest that in regions with complex topography, local processes change markedly over small spatial scales. One cannot necessarily infer that the dominant transport processes will be similar even in adjacent regions.

Estimating sediment accumulation rates in Manila Bay, a marine pollution hot spot in the Seas of East Asia.

Science.gov (United States)

Sta Maria, E J; Siringan, F P; Bulos, A dM; Sombrito, E Z

2009-01-01

The GEF/UNDP/IMO/PEMSEA project identifies Manila Bay as among the marine pollution hot spots in the Seas of East Asia. (210)Pb dating of its sediment can provide a historical perspective of its pollution loading. However, the validity of (210)Pb dating in a complex dynamic coastal system of Manila Bay may come into question. Land-based sediment input can be high and physical and biological processes can possibly disturb the sediment layers. In this report, the (210)Pb profiles of sediment cores from different parts of the bay are presented. The linear sedimentation rates are shown to be higher in the recent past and are also variable across the bay. The largest change in sedimentation rate, coincided with the occurrence of a volcanic eruption in 1991 and is shown by applying a variant of the CIC model in sedimentation rate calculations. The data suggest that (210)Pb dating can be useful in estimating relative magnitudes of sedimentation rates, even in a complex dynamic coastal system like Manila Bay.

Bay-scale population structure in coastal Atlantic cod in Labrador and Newfoundland, Canada

DEFF Research Database (Denmark)

Ruzzante, D.E.; Wroblewski, J.S.; Taggart, C.T.

2000-01-01

Polymorphisms at five microsatellite DNA loci provide evidence that Atlantic cod Gadus morhua inhabiting Gilbert Bay, Labrador are genetically distinguishable from offshore cod on the north- east Newfoundland shelf and from inshore cod in Trinity Bay, Newfoundland. Antifreeze activity in the bloo...

2010 NOAA Ortho-rectified Mosaic from Color Aerial Imagery of CHOCTAWHATCHEE BAY

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative of CHOCTAWHATCHEE BAY....

Monitoring coastal water properties and current circulation with ERTS-1. [Delaware Bay

Science.gov (United States)

Klemas, V.; Otley, M.; Wethe, C.; Rogers, R.

1974-01-01

Imagery and digital tapes from nine successful ERTS-1 passes over Delaware Bay during different portions of the tidal cycle have been analyzed with special emphasis on turbidity, current circulation, waste disposal plumes and convergent boundaries between different water masses. ERTS-1 image radiance correlated well with Secchi depth and suspended sediment concentration. Circulation patterns observed by ERTS-1 during different parts of the tidal cycle, agreed well with predicted and measured currents throughout Delaware Bay. Convergent shear boundaries between different water masses were observed from ERTS-1. In several ERTS-1 frames, waste disposal plumes have been detected 36 miles off Delaware's Atlantic coast. The ERTS-1 results are being used to extend and verify hydrodynamic models of the bay, developed for predicting oil slick movement and estimating sediment transport.

Pollution from organic contaminants in Greek marine areas, receiving anthropogenic pressures from intense activities in the coastal zone

Science.gov (United States)

Hatzianestis, Ioannis

2014-05-01

Polycyclic aromatic hydrocarbons (PAHs) are widespread pollutants in marine sediments, receiving the pressures from various anthropogenic activities in the coastal zone. Due to their mutagenic and carcinogenic behaviour, PAHs are classified as priority contaminants to be monitored in environmental quality control schemes. The purpose of this study was to determine the levels of PAHs in coastal areas of Greece directly influenced from the operation of major industrial units in the coastal zone, investigate their sources and evaluate their potential toxicity by comparison against effect - based sediment quality guidelines. Thirty two surface sediment samples were collected from three areas of the Hellenic coastline: a) Antikyra bay in Korinthiakos gulf, influenced from the operation of an alumina and aluminium production plant b) Larymna bay in Noth Evoikos gulf, influenced from the operation of a nickel production plant and c) Aliveri bay in South Evoikos Gulf, influenced from a cement production plant. In all the areas studied, aquaculture and fishing activities have been also developed in the coastal zone. PAH concentrations were determined by GC-MS, after soxhlet extraction and fractionation by silica column chromatography. PAH sources and origin were investigated by applying several isomeric ratio diagnostic criteria. The mean quotient Effect- Range Median (m-ERM) was used to evaluate the potential of adverse effects posed to benthic organisms. Three m-ERM-q values were used to differentiate the probability of observing toxicity and classify sites into four categories: sediments with m-ERM1.5 have the highest probability (76%) of toxicity. Extremely high PAH concentrations more than 100,000 ng/g were found in the close vicinity of the alumina production plant in Antikyra bay. High levels of PAHs up to 22,000 ng/g were also found in Aliveri bay, whereas lowest values, but still indicating significant pollution, were measured close to the nickel production plant

Evaluating the Impact of Land Use Change on Submerged Aquatic Vegetation Stressors in Mobile Bay

Science.gov (United States)

Al-Hamdan, Mohammad; Estes, Maurice G., Jr.; Quattrochi, Dale; Thom, Ronald; Woodruff, Dana; Judd, Chaeli; Ellis, Jean; Watson, Brian; Rodriquez, Hugo; Johnson, Hoyt

2009-01-01

Alabama coastal systems have been subjected to increasing pressure from a variety of activities including urban and rural development, shoreline modifications, industrial activities, and dredging of shipping and navigation channels. The impacts on coastal ecosystems are often observed through the use of indicator species. One such indicator species for aquatic ecosystem health is submerged aquatic vegetation (SAV). Watershed and hydrodynamic modeling has been performed to evaluate the impact of land use change in Mobile and Baldwin counties on SAV stressors and controlling factors (temperature, salinity, and sediment) in Mobile Bay. Watershed modeling using the Loading Simulation Package in C++ (LSPC) was performed for all watersheds contiguous to Mobile Bay for land use scenarios in 1948, 1992, 2001, and 2030. Landsat-derived National Land Cover Data (NLCD) were used in the 1992 and 2001 simulations after having been reclassified to a common classification scheme. The Prescott Spatial Growth Model was used to project the 2030 land use scenario based on current trends. The LSPC model simulations provided output on changes in flow, temperature, and sediment for 22 discharge points into the Bay. Theses results were inputted in the Environmental Fluid Dynamics Computer Code (EFDC) hydrodynamic model to generate data on changes in temperature, salinity, and sediment on a grid with four vertical profiles throughout Mobile Bay. The changes in the aquatic ecosystem were used to perform an ecological analysis to evaluate the impact on SAV habitat suitability. This is the key product benefiting the Mobile Bay coastal environmental managers that integrates the influences of temperature, salinity, and sediment due to land use driven flow changes with the restoration potential of SAVs.

Strain-induced shear instability in Liverpool Bay

Science.gov (United States)

Wihsgott, Juliane; Palmer, Matthew R.

2013-04-01

Liverpool Bay is a shallow subsection of the eastern Irish Sea with large tides (10 m), which drive strong tidal currents (1 ms-1). The Bay is heavily influenced by large freshwater inputs from several Welsh and English rivers that maintain a strong and persistent horizontal density gradient. This gradient interacts with the sheared tidal currents to strain freshwater over denser pelagic water on a semi-diurnal frequency. This Strain-Induced-Periodic-Stratification (SIPS) has important implications on vertical and horizontal mixing. The subtle interaction between stratification and turbulence in this complex environment is shown to be of critical importance to freshwater transport, and subsequently the fate of associated biogeochemical and pollutant pathways. Recent work identified an asymmetry of current ellipses due to SIPS that increases shear instability in the halocline with the potential to enhance diapycnal mixing. Here, we use data from a short, high intensity process study which reveals this mid-water mechanism maintains prolonged periods of sub-critical gradient Richardson number (Ri ≤ ¼) that suggests shear instability is likely. A time series of measurements from a microstructure profiler identifies the associated increase in turbulence is short lived and 'patchy' but sufficient to promote diapycnal mixing. The significance of this mixing process is further investigated by comparing our findings with long-term observations from the Liverpool Bay Coastal Observatory. We identify that the conditions for shear instability during SIPS are regularly met and suggest that this process contributes to the current underestimates of near coastal mixing observed in regional models. To assist our understanding of the observed processes and to test the current capability of turbulence 'closure schemes' we employ a one-dimensional numerical model to investigate the physical mechanisms driving diapycnal mixing in Liverpool Bay.

Marine organic geochemistry in industrially affected coastal areas in Greece: Hydrocarbons in surface sediments

Science.gov (United States)

Hatzianestis, Ioannis

2015-04-01

Hydrocarbons are abundant components of the organic material in coastal zones. Their sources are mainly anthropogenic, but several natural ones have also been recognized. Among hydrocarbons, the polycyclic aromatic ones (PAHs) have received special attention since they considered as hazardous environmental chemicals and are included in priority pollutant lists. The purpose of this study was to investigate the distribution, sources and transport pathways of hydrocarbons in marine areas in Greece directly influenced from the operation of major industrial units in the coastal zone by using a molecular marker approach, characteristic compositional patterns and related indices and also to evaluate their potential toxicity. Thirty two surface sediment samples were collected from three marine areas: a) Antikyra bay in Korinthiakos gulf, affected from the operation of an alumina and production plant b) Larymna bay in Noth Evoikos, affected from the operation of a nickel production plant and c) Aliveri bay in South Evoikos Gulf, affected from a cement production plant. In all the studied areas aquaculture and fishing activities have been also developed in the coastal zone. High aliphatic hydrocarbon (AHC) concentrations (~500 μg/g), indicating significant petroleum related inputs, were measured only in Antikyra bay. In all the other samples, AHC values were below 100 μg/g. N-alkanes were the most prominent resolved components (R) with an elevated odd to even carbon number preference, revealing the high importance of terrestrial inputs in the study areas. The unresolved complex mixture (UCM) was the major component of the aliphatic fraction (UCM/R > 4), indicating a chronic oil pollution. A series of hopanes were also identified, with patterns characteristic of oil-derived hydrocarbons, further confirming the presence of pollutant inputs from fossil fuel products. Extremely high PAH concentrations (> 100,000 ng/g) were found in the close vicinity of the alumina production

Large-Scale Submerged Aquatic Vegetation Restoration in Chesapeake Bay: Status Report, 2003-2006

Science.gov (United States)

2008-06-01

seed injector designed by VIMS, which does not require a gel matrix, has been tested in Spider Crab Bay in Virginia’s Coastal Bays (Figures 13 and 14...seagrasses, contributing to their loss. Additionally, waters landward of restrictive breakwaters tend to be warmer ( blue and red thermometers) than those...marina), (2) wild celery (V. americana), (3) sago pondweed (S. pectinata), and (4) redhead grass (P. perfoliatus). Molecular and cultivation

The potential use of mussel farms in German coastal waters as an option to improve water quality

DEFF Research Database (Denmark)

Friedland, René; Maar, Marie

Many German coastal waters like Szczecin (Oder) Lagoon or Bay of Greifswald are strongly used, heavily polluted by nutrients and at the same time a crucial supplier of ecosystem services. Although, nutrient loads have been decreased over the last decade, water quality of most coastal waters...... remained bad characterized by low macrophytes coverage and secchi depth caused by high phytoplankton densities and strong resuspension of sediments. Hence the Good Environmental Status claimed by EU`s Water Framework Directive will not be achieved in most coastal waters. Introducing mussel farming...... techniques is seen as an option to reduce the phytoplankton densities and to improve water transparency, e.g. in Kiel Bay a first farm using Mytilus edulis is running. Unfortunately, most German coastal waters have only low salinities causing a limited growth of Mytilus spp. or make it even impossible – like...

Sediment biogeochemistry in an East African mangrove forest (Gazi Bay, Kenya)

NARCIS (Netherlands)

Middelburg, J.J.; Nieuwenhuize, J.; Slim, F.J.; Ohowa, B.

1996-01-01

The biogeochemistry of mangrove sediments was investigated in several mangrove forest communities in Gazi Bay, a coastal lagoon in Kenya, Africa. Carbon dioxide fluxes, sediment median grain sizes, sedimentary organic carbon, nitrogen and phosphorus contents and pore-water characteristics (ammonium,

Atmospheric ammonia measurements along the coastal lines of Southeastern China: Implications for inorganic nitrogen deposition to coastal waters

Science.gov (United States)

Wu, Shui-Ping; Dai, Lu-Hong; Wei, Ya; Zhu, Heng; Zhang, Yin-Ju; Schwab, James J.; Yuan, Chung-Shin

2018-03-01

Ambient NH3 concentrations were determined using Ogawa passive samplers along the coastal lines of southeast China from June 2015 to May 2017. Additional monitoring of PM2.5 and precipitation around Xiamen Bay during the period from November 2015 to May 2017 were carried out to estimate atmospheric inorganic nitrogen (IN) deposition to the bay. Distinct seasonal variations of ambient NH3 were observed with summer averages 1.41-5.56 times higher than winter, which agreed well with the seasonal trend of air temperature. Nitrate concentrations (pNO3-) in PM2.5 were significantly higher than ammonium concentrations (pNH4+), and both species showed higher concentrations in winter and spring and lower values in summer and fall which were influenced mainly by the monsoon cycle, gas-to-particle transformation process and rain washout. Paired t-testing revealed that no significant differences of pNO3- and pNH4+ between the urban and suburban sites around the Xiamen Bay. Unlike pNO3- and pNH4+, there were no clear seasonal trends for NH4+ and NO3- concentrations in precipitation samples (wNH4+ and wNO3-). On average, the deposition of IN consisted of NH3-N (27.4-28.2%) and pNO3--N (25.9-26.8%), followed by pNH4+-N (17.0-17.7%), wNH4+-N (14.5%), wNO3--N (13.3-13.8%) and NO2-N (0.35-0.46%); and showed distinct seasonal trends with higher values in winter/spring and lower values in summer/fall. In 2016, the total IN deposition was determined to be 36.45 and 35.92 kg N ha-1 at the urban and suburban sites around the Xiamen Bay, respectively. The proportion of IN deposition to total IN loads (terrestrial + atmospheric), varied over the range of 7.1-13.3% depending on the data source of riverine influx. Our observations revealed that the total IN deposition could account for 9.6-25.1% (based on primary productivity over Taiwan Strait) and 1.7-5.3% (based on primary productivity in Guangdong coastal region) of new productivity in Xiamen Bay, respectively. As an important nutrient

Accuracy assessment of satellite Ocean colour products in coastal waters.

Science.gov (United States)

Tilstone, G.; Lotliker, A.; Groom, S.

2012-04-01

The use of Ocean Colour Remote Sensing to monitor phytoplankton blooms in coastal waters is hampered by the absorption and scattering from substances in the water that vary independently of phytoplankton. In this paper we compare different ocean colour algorithms available for SeaWiFS, MODIS and MERIS with in situ observations of Remote Sensing Reflectance, Chlorophyll-a (Chla), Total Suspended Material and Coloured Dissolved Organic Material in coastal waters of the Arabian Sea, Bay of Bengal, North Sea and Western English Channel, which have contrasting inherent optical properties. We demonstrate a clustering method on specific-Inherent Optical Properties (sIOP) that gives accurate water quality products from MERIS data (HYDROPT) and also test the recently developed ESA CoastColour MERIS products. We found that for coastal waters of the Bay of Bengal, OC5 gave the most accurate Chla, for the Arabian Sea GSM and OC3M Chla were more accurate and for the North Sea and Western English Channel, MERIS HYDROPT were more accurate than standard algorithms. The reasons for these differences will be discussed. A Chla time series from 2002-2011 will be presented to illustrate differences in algorithms between coastal regions and inter- and intra-annual variability in phytoplankton blooms

The ichthyoplankton assemblage of the Algoa Bay nearshore region ...

African Journals Online (AJOL)

The ichthyoplankton assemblage of the Algoa Bay nearshore region in relation to coastal zone utilization by juvenile fish. ... The various taxa occurring in the ichthyoplankton are discussed in terms of distribution of adults and juveniles, breeding biology and available information on early life history. The paucity of larvae of ...

Depth profile distribution of Cr, Cu, Co, Ni and Pb in the sediment cores of Mumbai Harbour Bay

International Nuclear Information System (INIS)

Madhuparna, D.; Hemalatha, P.; Raj, Sanu S.; Jha, S.K.; Tripathi, R.M.

2014-01-01

Estuarine and coastal sediments act as ultimate sink for trace metals that are discharged into the aquatic environment. Sources of environmental contaminants to the coastal system are numerous and may enter the estuarine environment via a number of pathways Mumbai Harbour Bay on the western coast of India, receives low level nuclear wastes and industrial and domestic sewage waste from the surrounding dwellings. Also, the bay is extensively exploited for various other local activities. The present study was carried out in the bay sediment cores to investigate the depth profile distribution of trace element concentration. Biologically significant toxic elements such as Cr, Cu, Co, Ni and Pb were estimated in the sediment cores to find out pattern of distribution in the sediment bed to follow the accumulation of elements with respect to depth

Hurricane Sandy science plan: coastal impact assessments

Science.gov (United States)

Stronko, Jakob M.

2013-01-01

Hurricane Sandy devastated some of the most heavily populated eastern coastal areas of the Nation. With a storm surge peaking at more than 19 feet, the powerful landscape-altering destruction of Hurricane Sandy is a stark reminder of why the Nation must become more resilient to coastal hazards. In response to this natural disaster, the U.S. Geological Survey (USGS) received a total of $41.2 million in supplemental appropriations from the Department of the Interior (DOI) to support response, recovery, and rebuilding efforts. These funds support a science plan that will provide critical scientific information necessary to inform management decisions for recovery of coastal communities, and aid in preparation for future natural hazards. This science plan is designed to coordinate continuing USGS activities with stakeholders and other agencies to improve data collection and analysis that will guide recovery and restoration efforts. The science plan is split into five distinct themes: coastal topography and bathymetry, impacts to coastal beaches and barriers, impacts of storm surge, including disturbed estuarine and bay hydrology, impacts on environmental quality and persisting contaminant exposures, impacts to coastal ecosystems, habitats, and fish and wildlife. This fact sheet focuses assessing impacts to coastal beaches and barriers.

Anthropogenic effects on shoreface and shoreline changes: Input from a multi-method analysis, Agadir Bay, Morocco

Science.gov (United States)

Aouiche, Ismail; Daoudi, Lahcen; Anthony, Edward J.; Sedrati, Mouncef; Ziane, Elhassane; Harti, Abderrazak; Dussouillez, Philippe

2016-02-01

In many situations, the links between shoreline fluctuations and larger-scale coastal change embracing the shoreface are not always well understood. In particular, meso-scale (years to decades) sand exchanges between the shoreface and the shoreline, considered as important on many wave-dominated coasts, are rather poorly understood and difficult to identify. Coastal systems where sediment transport is perturbed by engineering interventions on the shoreline and shoreface commonly provide fine examples liable to throw light on these links. This is especially so where shoreface bathymetric datasets, which are generally lacking, are collected over time, enabling more or less fine resolution of the meso-scale coastal sediment budget. Agadir Bay and the city of Agadir together form one of the two most important economic development poles on the Atlantic coast of Morocco. Using a combined methodological approach based on wave-current modelling, bathymetric chart-differencing, determination of shoreline fluctuations, and beach topographic surveying, we highlight the close links between variations in the bed of the inner shoreface and the bay shoreline involving both cross-shore and longshore sand transport pathways, sediment budget variations and new sediment cell patterns. We show that the significant changes that have affected the bay shoreline and shoreface since 1978 clearly reflect anthropogenic impacts, notably blocking of alongshore sand transport by Agadir harbour, completed in 1988, and the foundations of which lie well beyond the depth of wave closure. Construction of the harbour has led to the creation of a rapidly accreting beach against an original portion of rocky shoreline updrift and to a net sand loss exceeding 145,000 m3/year between 1978 and 2012 over 8.5 km2of the bay shoreface downdrift. Shoreline retreat has been further exacerbated by sand extraction from aeolian dunes and by flattening of these dunes to make space for tourist infrastructure. Digital

High 210Po atmospheric deposition flux in the subtropical coastal area of Japan

International Nuclear Information System (INIS)

Tateda, Yutaka; Iwao, Kenji

2008-01-01

Bulk atmospheric deposition fluxes of 210 Po and 210 Pb were measured at three coastal regions of Japan, the Pacific Ocean coastal area of the Japanese mainland (Odawa Bay), the Chinese continental side of Japanese coastal area (Tsuyazaki), and an isolated island near Okinawa (Akajima). Wet and dry fallout collectors were continuously deployed from September 1997 through August 1998 for periods of 3 to 31 days depending on the frequency of precipitation events. Annual 210 Pb deposition fluxes at Odawa Bay (35 o N 139 o E), Tsuyazaki (33 o N 130 o E) and Akajima (26 o N 127 o E) were 73.3 ± 8.0, 197 ± 35 and 78.5 ± 8.0 Bq m -2 y -1 , respectively. Higher 210 Pb deposition was observed at the Chinese continental side of Japanese coast than at the Pacific Ocean coastal site. The high 210 Pb atmospheric flux at the Chinese continental side coast was thought to be attributable to 222 Rn-rich air-mass transport from the Chinese continent during the winter monsoon. In contrast, the annual 210 Po deposition fluxes at the three study sites were 13.0 ± 2.3 (Odawa Bay), 21.9 ± 4.4 (Tsuyazaki) and 58.4 ± 7.7 (Akajima) Bq m -2 y -1 , respectively, indicating unusual high 210 Po deposition at Akajima during winter. Anomalous unsupported 210 Po input was observed during summer 1997, suggesting unknown source of 210 Po at this area

Remote sensing of coastal fronts and their effects on oil dispersion

Energy Technology Data Exchange (ETDEWEB)

Klemas, V

1980-01-01

The use of remote sensing techniques to determine the properties of coastal and estuarine fronts, which represent regions of discontinuities and high gradients in ocean physical parameters such as velocity and density, and to assess the influence of such fronts on oil pollutants is discussed. Results of an aircraft and boat verification study of an oil drift and spread model in Delaware Bay are indicated which illustrate the tendency of oil slicks to be attracted to frontal regions, where a denser fluid underlies a lighter fluid giving rise to an inclined interface with convergence zones. Landsat imagery of the bay acquired in order to incorporate frontal information into the interactive computer model is then presented which allows the locations of coastal fronts to be charted throughout a tidal cycle. It is noted that satellite observations of flood-associated fronts on the New Jersey side of the bay and ebb-associated fronts on the Delaware side agree with boat measurements and model predictions, and that the remote tracking of fronts by aircraft and satellites will aid in oil slick clean-up operations.

Comparison of Qinzhou bay wetland landscape information extraction by three methods

Directory of Open Access Journals (Sweden)

X. Chang

2014-04-01

and OO is 219 km2, 193.70 km2, 217.40 km2 respectively. The result indicates that SC is in the f irst place, followed by OO approach, and the third DT method when used to extract Qingzhou Bay coastal wetland.

Mercury dynamics in a coastal aquifer: Maunalua Bay, O´ahu, Hawai´i

Science.gov (United States)

Ganguli, Priya M.; Swarzenski, Peter W.; Dulaiova, Henrieta; Glenn, Craig R.; Flegal, A. Russell

2014-03-01

We evaluated the influence of groundwater-seawater interaction on mercury dynamics in Maunalua Bay, a coral reef ecosystem located on the south shore of O´ahu, Hawai´i, by combining geochemical data with submarine groundwater discharge (SGD) rates. During a rising tide, unfiltered total mercury (U-HgT) concentrations in seawater increased from ˜6 to 20 pM at Black Point (west Bay) and from ˜2.5 to 8 pM at Niu (central Bay). We attribute this change to an increase in suspended particulate matter at high tide. Approximately 90% of mercury in groundwater at Niu was in the filtered (weighted average Maunalua Bay groundwater mercury flux of 0.68 ± 0.67 mol yr-1 by combining the proportional flux of F-HgT from three distinct SGD zones, and place these results into a broader context by comparing and contrasting flux estimates from locations around the world. Results from existing SGD studies should be evaluated to develop future sampling strategies that address more targeted questions about mercury biogeochemical cycling at the groundwater-seawater interface.

Nutrient and physical profile data from four Microbial Exchanges and Coupling in Coastal Atlantic Systems (MECCAS) cruises collected aboard the R/V Gyre at the mouth of the Chesapeake Bay and northern Atlantic Ocean from February 17, 1985 to September 7, 1986 (NODC Accession 8800324)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Microbial Exchanges and Coupling in Coastal Atlantic Systems (MECCAS) cruise data collected aboard the R/V Gyre at the mouth of the Chesapeake Bay and northern...

Flooding Simulation of Extreme Event on Barnegat Bay by High-Resolution Two Dimensional Hydrodynamic Model

Science.gov (United States)

Wang, Y.; Ramaswamy, V.; Saleh, F.

2017-12-01

Barnegat Bay located on the east coast of New Jersey, United States and is separated from the Atlantic Ocean by the narrow Barnegat Peninsula which acts as a barrier island. The bay is fed by several rivers which empty through small estuaries along the inner shore. In terms of vulnerability from flooding, the Barnegat Peninsula is under the influence of both coastal storm surge and riverine flooding. Barnegat Bay was hit by Hurricane Sandy causing flood damages with extensive cross-island flow at many streets perpendicular to the shoreline. The objective of this work is to identify and quantify the sources of flooding using a two dimensional inland hydrodynamic model. The hydrodynamic model was forced by three observed coastal boundary conditions, and one hydrologic boundary condition from United States Geological Survey (USGS). The model reliability was evaluated with both FEMA spatial flooding extend and USGS High water marks. Simulated flooding extent showed good agreement with the reanalysis spatial inundation extents. Results offered important perspectives on the flow of the water into the bay, the velocity and the depth of the inundated areas. Using such information can enable emergency managers and decision makers identify evacuation and deploy flood defenses.

Bat response to carolina bays and wetland restoration in the southeastern U.S. Coastal Plain.

Energy Technology Data Exchange (ETDEWEB)

Menzel, Jennifer M.; Michael A. Menzel; John C. Kilgo; W. Mark Ford; ; John W. Edwards.

2005-09-01

Abstract: Bat activity in the southeastern United States is concentrated over riparian areas and wetland habitats. The restoration and creation of wetlands for mitigation purposes is becoming common in the Southeast. Understanding the effects of these restoration efforts on wetland flora and fauna is thus becoming increasingly important. Because bats (Order: Chiroptera) consist of many species that are of conservation concern and are commonly associated with wetland and riparian habitats in the Southeast (making them a good general indicator for the condition of wetland habitats), we monitored bat activity over restored and reference Carolina bays surrounded by pine savanna (Pinus spp.) or mixed pine-hardwood habitat types at the Savannah River Site in South Carolina. In order to determine how wetland restoration efforts affected the bat community, we monitored bat activity above drained Carolina bays pre- and post-restoration. Our results indicate that bat activity was greater over reference (i.e., undrained) than drained bays prior to the restorative efforts. One year following combined hydrologic and vegetation treatment, however, bat activity was generally greater over restored than reference bays. Bat activity was also greater over both reference and restored bays than in random, forested interior locations. We found significantly more bat activity after restoration than prior to restoration for all but one species in the treatment bays, suggesting that Carolina bay restoration can have almost immediate positive impacts on bat activity.

Coastal Mapping Program Project MN1501: SILVER BAY, MN.

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The objective of the Coastal Mapping Program (CMP) is to provide surveying and mapping information of our nation's coastline. This shoreline mapping effort also...

Coastal Bend Texas Benthic Habitat Mapping Patchy Shapefile Map - Lower Laguna Madre

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Office for Coastal Management (OCM) requested the creation of benthic habitat data along the southern Texas coast to support the Texas Seagrass Monitoring...

Evaluation of comprehensive environmental effect about coastal zone development activities in Liaoning Province and management advice.

Science.gov (United States)

Wang, Wei-Wei; Cai, Yue-Yin; Sun, Yong-Guang; Ma, Hong-Wei

2015-07-01

Using spatial analysis function of Arcgis software, the present study investigated the building environment impact evaluation index system of coastal development in Liaoning Province. The factors of it included of current state of environmental quality, environmental impact of marine development and marine environmental disaster. Weighted factor analysis and comprehensive index method were utilized. At the end, comprehensive environment effect of coastal development in Liaoning Province were evaluated successfully. The result showed that the environmental effect of development activity were most serious, along the Zhao Jiatun coast in north of Zhimao bay and coast of Mianhua island in Dalian bay.

Measuring Macrobenthos Biodiversity at Oyster Aquaculture Sites in the Delaware Inland Bays

Science.gov (United States)

Fuoco, M. J.; Ozbay, G.

2016-12-01

The Delaware Inland Bays consists of three shallow coastal bays located in the southern portion of Delaware. Anthropogenic activities have led to the degradation of water quality, because the bays are surrounded by highly developed areas and have low flushing rates. This results in loss of biodiversity and abundance of organisms. Ongoing degradation of the bays has led to a dramatic decline in local oyster populations since the late 1800s. Oysters are keystone species, which provide habitats for organisms and help to improve water quality. This study aims to find if the introduction of oyster aquaculture improves local biodiversity and abundance of macrobenthos. The study was conducted in Rehoboth Bay, Indian River Bay and Little Assawoman Bay. Aquaculture gear was placed at one location in each of the bays and 24 sediment core samples were taken once a month. From these core samples all worms were fixed and stained in a 10% Formalin Rose Bengal solution and preserved in 70% Ethanol for later identification. Stable carbon and nitrogen isotope analysis of oyster tissue will also be performed to assess the health of the bay. The goals of this research are to better understand the role of oyster aquaculture in restoring the viability and health of the Delaware Inland Bays.

A coupled modelling system for the Irish Sea and Liverpool Bay with application to coastal flood forecasting and beyond

Science.gov (United States)

Wolf, J.; Bricheno, L. R.; Brown, J. E.; Bolaños, R.

2012-04-01

The POLCOMS-WAM coupled wave and hydrodynamic model has been implemented at 1.8km resolution for the Irish Sea and 180m in a nested model of Liverpool Bay. It can be forced with output from the UK Met Office Unified Model. This allows the use of Smith and Banke (1975) and Charnock (1955) formulations for the wind-stress. The former gives an underestimate of the wind-stress, requiring enhanced winds for accurate surge hindcasts. While the latter gives good results for the Irish Sea and Liverpool Bay, with different values of the Charnock coefficient, it also allows the inclusion of a coupled wave stress into the wind-stress (Brown and Wolf, 2009). New results have been obtained by using wind and pressures from the WRF atmospheric model, allowing further development of air-sea coupling. The coupled model also includes bottom friction and the Doppler shift of the waves by the depth-averaged current), as well as advanced coupling procedures: use of the 3D current in the wave physics and calculation of radiation stress and Stokes' drift (Brown et al., 2011). During storm conditions it is found that the radiation stress is the most important term in this shallow water application. However, WAM runs in near real time, making this model only practical for research purposes. The model system has been used to hindcast tides, surges and waves in Liverpool Bay. Data are readily available from the Liverpool Bay Coastal Observatory to quantify the importance of each coupled term with the aim of producing the most accurate model setup for coastal forecasting. A storm event, 18th January 2007, has been hindcast to investigate extreme tide-surge-wave condition both offshore and inshore. During storm events, wave setup in shallow regions can contribute significantly to the total water elevation. The application of a 2D method to calculate radiation stress in a 3D hydrodynamic model is thoroughly examined by comparison with observations and a 3D model (Mellor, 2003). The results show

Effects of small-scale hydrogeologic heterogeneity on submarine groundwater discharge (SGD) dynamics in river dominated estuaries: example of Mobile Bay, Alabama

Science.gov (United States)

Montiel, D.; Dimova, N.

2017-12-01

Submarine groundwater discharge (SGD) is known to be an important pathway for nutrients and dissolved constituents in estuarine environments worldwide. Despite its limited contribution to the total fresh water flux to the ocean (5 - 10 %), SGD-derived material loadings can rival riverine inputs. Therefore, a good understanding of the coastal hydrogeology and subsequent SGD dynamics is crucial to further investigate constituent fluxes and its implications on small and large scale coastal ecosystems. We evaluated SGD in Mobile Bay (Alabama), the fourth largest estuary in the US, using a combination of radiotracer techniques (223Ra, 226Ra, and 222Rn), stable isotopes (δ 18O and δ 2H), geophysical surveys (continuous resistivity profiling (CRP) and electrical resistivity tomography (ERT)), and seepage meters during three consecutive years. A detailed examination of the entire shoreline of Mobile Bay using CRP, ERT imaging, and multiple sediment cores collection unveiled a heterogeneous (horizontal and vertical) distribution of the surficial coastal aquifer. This was reflected and confirmed by groundwater tracer measurements and direct measurements of SGD in the coastal zone. We found that SGD occurs mainly in the northeast section of Mobile Bay with a total flux that ranged between 0.9 and 13 × 105 m3 d-1 during dry and wet periods, which represents 0.4 - 2 % of the total fresh water inputs into the Bay. While total SGD is insignificant when accounting the whole water budget of Mobile Bay, we found that small-scale geology variations produce groundwater flow preferential pathways in particular areas where SGD inputs play an important role in the water and nutrient budgets.

Seagrass status and trends in the northern Gulf of Mexico: 1940-2002

Science.gov (United States)

Handley, L.; Altsman, D.; DeMay, R.

2007-01-01

Over the past century, seagrass habitats from the bays of Texas to the gulf shores of Florida have decreased. Seagrass beds, which are highly dependent on water quality and clarity for survival, are home to a multitude of aquatic plants and animals and a source of economic activity through commercial and recreational fishing and ecotourism. The U.S. Environmental Protection Agency’s Gulf of Mexico Program (GMP) and its partners have made a commitment to restore, enhance, and protect this important ecosystem. As seagrass habitats decrease, the need for information on the causes and effects of seagrass loss, current mapping information, and education on the importance of seagrassess becomes greater. This report is the initial effort of the GMP’s research and restoration plan for seagrasses. The purpose of this report is to provide scientists, managers, and citizens with valuable baseline information on the status and trends of seagrasses in coastal waters of the Gulf of Mexico. Within the northern Gulf of Mexico region, 14 individual estuarine systems where seagrasses occur, as well as statewide summaries for Texas, Louisiana, Mississippi, Alabama, and Florida, are examined in this study. Each estuarine system is detailed in vignettes that address current and historical extent and quality of seagrasses, seagrass mapping and monitoring, causes of status change, restoration and enhancement activities, background information for the entire study area as well as the subareas for study, and the methodology employed to analyze and document the historical trends and current status of seagrasses. The systems, moving from west to east, include the Laguna Madre, Texas Coastal Bend region, and Galveston Bay in Texas; the Chandeleur Islands in Louisiana; the Mississippi Sound; and Perdido Bay, Pensacola/Escambia Bay, Choctawhatchee Bay, St. Andrew Bay, Florida’s Big Bend region, Tampa Bay/St. Joseph Sound, Sarasota Bay, Greater Charlotte Harbor, and Florida Bay in Florida

Finite Element Analysis for Bending Process of U-Bending Specimens

Energy Technology Data Exchange (ETDEWEB)

Park, Won Dong; Bahn, Chi Bum [Pusan National University, Busan (Korea, Republic of)

2015-10-15

ASTM G30 suggests that the applied strain can be calculated by dividing thickness by a bend radius. It should be noted, however, that the formula is reliable under an assumption that the ratio of thickness to bend radius is less than 0.2. Typically, to increase the applied stress/strain, the ratio of thickness to bend radius becomes larger than 0.2. This suggests that the estimated strain values by ASTM G30 are not reliable to predict the actual residual strain state of the highly deformed U-bend specimen. For this reason, finite element analysis (FEA) for the bending process of Ubend specimens was conducted by using a commercial finite element analysis software ABAQUS. ver.6.14- 2;2014. From the results of FEA, PWSCC initiation time and U-bend specimen size can be determined exactly. Since local stress and strain have a significant effect on the initiation of PWSCC, it was inappropriate to apply results of ASTM G30 to the PWSCC test directly. According to results of finite element analysis (FEA), elastic relaxation can cause inaccuracy in intended final residual stress. To modify this inaccuracy, additional process reducing the spring back is required. However this additional process also may cause uncertainty of stress/strain state. Therefore, the U-bending specimen size which is not creating uncertainty should be optimized and selected. With the bending radius of 8.3 mm, the thickness of 3 mm and the roller distance of 32.6 mm, calculated maximum stress and strain were 670 MPa and 0.21, respectively.

In-plane and out-of-plane bending tests on carbon steel pipe bends

International Nuclear Information System (INIS)

Brouard, D.; Tremblais, A.; Vrillon, B.

1979-01-01

The objectives of these tests were to obtain experimental results on bends behaviour in elastic and plastic regime by in plane and out of plane bending. Results were used to improve the computer model, for large distorsion of bends, to be used in a simplified beam type computer code for piping calculations. Tests were made on type ANSI B 169 DN 5 bends in ASTM A 106 Grade B carbon steel. These tests made it possible to measure, for identical bends, in elastic regime, the flexibility factors and, in plastic regime, the total evolution in opening, in closing and out of plane. Flexibility factors of 180 0 bend without flanges are approximately the same in opening and in closing. The end effect due to flanges is not very significant, but it is important for 90 0 bends. In plastic regime, collapse loads or collapse moments of bends depends also of both the end effects and the angle bend. The end effects and the angle bend are more sensitive in opening than in closing. The interest of these tests is to procure some precise evolution curves of identical bends well characterized in geometry and metal strength, deflected in large distorsions. (orig./HP)

A Landsat-Based Assessment of Mobile Bay Land Use and Land Cover Change from 1974 to 2008

Science.gov (United States)

Spruce, Joseph; Ellis, Jean; Smoot, James; Swann, Roberta; Graham, William

2009-01-01

The Mobile Bay region has experienced noteworthy land use and land cover (LULC) change in the latter half of the 20th century. Accompanying this change has been urban expansion and a reduction of rural land uses. Much of this LULC change has reportedly occurred since the landfall of Hurricane Frederic in 1979. The Mobile Bay region provides great economic and ecologic benefits to the Nation, including important coastal habitat for a broad diversity of fisheries and wildlife. Regional urbanization threatens the estuary s water quality and aquatic-habitat dependent biota, including commercial fisheries and avian wildlife. Coastal conservation and urban land use planners require additional information on historical LULC change to support coastal habitat restoration and resiliency management efforts. This presentation discusses results of a Gulf of Mexico Application Pilot project that was conducted in 2008 to quantify and assess LULC change from 1974 to 2008. This project was led by NASA Stennis Space Center and involved multiple Gulf of Mexico Alliance (GOMA) partners, including the Mobile Bay National Estuary Program (NEP), the U.S. Army Corps of Engineers, the National Oceanic and Atmospheric Administration s (NOAA s) National Coastal Data Development Center (NCDDC), and the NOAA Coastal Services Center. Nine Landsat images were employed to compute LULC products because of their availability and suitability for the application. The project also used Landsat-based national LULC products, including coastal LULC products from NOAA s Coastal Change & Analysis Program (C-CAP), available at 5-year intervals since 1995. Our study was initiated in part because C-CAP LULC products were not available to assess the region s urbanization prior to 1995 and subsequent to post Hurricane Katrina in 2006. This project assessed LULC change across the 34-year time frame and at decadal and middecadal scales. The study area included the majority of Mobile and Baldwin counties that

Mercury dynamics in a coastal aquifer: Maunalua Bay, Oʻahu, Hawaiʻi

Science.gov (United States)

Ganguli, Priya M.; Swarzenski, Peter W.; Dulaiova, Henrieta; Glenn, Craig R.; Flegal, A. Russell

2014-01-01

We evaluated the influence of groundwater–seawater interaction on mercury dynamics in Maunalua Bay, a coral reef ecosystem located on the south shore of Oʻahu, Hawaiʻi, by combining geochemical data with submarine groundwater discharge (SGD) rates. During a rising tide, unfiltered total mercury (U-HgT) concentrations in seawater increased from ∼6 to 20 pM at Black Point (west Bay) and from ∼2.5 to 8 pM at Niu (central Bay). We attribute this change to an increase in suspended particulate matter at high tide. Approximately 90% of mercury in groundwater at Niu was in the filtered (weighted average Maunalua Bay groundwater mercury flux of 0.68 ± 0.67 mol yr−1 by combining the proportional flux of F-HgT from three distinct SGD zones, and place these results into a broader context by comparing and contrasting flux estimates from locations around the world. Results from existing SGD studies should be evaluated to develop future sampling strategies that address more targeted questions about mercury biogeochemical cycling at the groundwater–seawater interface.

Improving Sediment Transport Prediction by Assimilating Satellite Images in a Tidal Bay Model of Hong Kong

Directory of Open Access Journals (Sweden)

Peng Zhang

2014-03-01

Full Text Available Numerical models being one of the major tools for sediment dynamic studies in complex coastal waters are now benefitting from remote sensing images that are easily available for model inputs. The present study explored various methods of integrating remote sensing ocean color data into a numerical model to improve sediment transport prediction in a tide-dominated bay in Hong Kong, Deep Bay. Two sea surface sediment datasets delineated from satellite images from the Moderate Resolution Imaging Spectra-radiometer (MODIS were assimilated into a coastal ocean model of the bay for one tidal cycle. It was found that remote sensing sediment information enhanced the sediment transport model ability by validating the model results with in situ measurements. Model results showed that root mean square errors of forecast sediment both at the surface layer and the vertical layers from the model with satellite sediment assimilation are reduced by at least 36% over the model without assimilation.

A Study on U-bending Technology using Rotary Draw Bending

Energy Technology Data Exchange (ETDEWEB)

Kwak, Ok-gyu; Kim, Won-seok [BHI Co., Gyunsang-Namdo (Korea, Republic of); Ku, Tae-wan [Pusan National Univ., Busan (Korea, Republic of)

2014-10-15

In the steam generator, heat transfer phenomenon for producing the steam between the primary system of the nuclear reactor and the secondary one occurs around the heat transfer tube. That is, the primary coolant with high temperature(320 .deg.. C) and high pressure(157Kgf/cm2) derived from the reactor flows in the heat transfer tube, and the secondary one runs out that tube. Therefore, it is able to mention that the heat transfer tube itself is a boundary of the heat transfer phenomenon. The heat transfer tube bundle of each steam generator used for the PWR and the PHWR(Pressurized Heavy Water Reactor) is generally composed of about 8,000-13,000 U-tubes. And these tubes are the core component as the structural and heat transfer material in the steam generator, which is in charge of cooling about 70% of the cooling surface of the primary system. For achieving the U-bending process with the thin walled tube, generally, a mandrel could be inserted in the tube according to the bending radius. But when the bending radius is small, the tube U-bending process could be also performed without the mandrel. In this study, numerical and experimental investigations on the U-bending process for producing the heat transfer tubes by using the straight and long tubes were carried out with the consideration of the elastic recovery after the U-bending. In the numerical approach, finite element analysis scheme was adopted with a commercial code, ABAQUS Implicit/Explicit. As the precedent study, the related experiment was also performed to verify the predicted results on the ovality and the minimum wall thickness of the U-bending heat transfer tube. Furthermore, its bending process was also conducted to analyze the deformation behavior for the Alloy 690 tube. In this study, the U-bending process was considered to simulate and manufactured the heat transfer tube used for the steam generator. To investigate the deformation behavior of the U-bending process, and a series of the

Phytoplankton and nutrient dynamics in Winyah Bay, SC.

Science.gov (United States)

Boneillo, G. E.; Brooks, S. S.; Brown, S. L.; Woodford, K. M.; Wright, C. R.

2016-02-01

Winyah Bay is a coastal plain estuary located in South Carolina that has been classified for a moderate risk of Eutrophication by NOAA. Winyah Bay receives freshwater input from four rivers, the Waccamaw, Sampit, Black, and Pee Dee Rivers. The Waccamaw, Sampit and Black River are blackwater systems that discharge elevated amounts of colored dissolved organic matter. During the summer and fall of 2015, bioassay experiments were performed to simultaneously examine both light and nutrient (nitrogen & phosphate) limitation throughout Winyah Bay. Sampling stations near the mouth of the Waccamaw and Sampit Rivers showed that phytoplankton were light limited in the late summer instead of nutrient limited. These stations were located in the industrialized area of the bay and typically had the highest nutrient concentrations and highest turbidity, with Secchi depths typically less than 0.5 meters. Results indicated that phytoplankton may be nitrogen limited near the mouth of Winyah Bay, where nutrient concentrations and turbidity were observed to be lower than locations further upstream. There was also an observed dissolved oxygen and pH gradient during the summer of 2015. Dissolved oxygen levels less than 4.0 mg/L were routinely observed near the industrialized head of the estuary and corresponded with lower pH values.

Hindcasting of Storm Surges, Currents, and Waves at Lower Delaware Bay during Hurricane Isabel

Science.gov (United States)

Salehi, M.

2017-12-01

Hurricanes are a major threat to coastal communities and infrastructures including nuclear power plants located in low-lying coastal zones. In response, their sensitive elements should be protected by smart design to withstand against drastic impact of such natural phenomena. Accurate and reliable estimate of hurricane attributes is the first step to that effort. Numerical models have extensively grown over the past few years and are effective tools in modeling large scale natural events such as hurricane. The impact of low probability hurricanes on the lower Delaware Bay is investigated using dynamically coupled meteorological, hydrodynamic, and wave components of Delft3D software. Efforts are made to significantly reduce the computational overburden of performing such analysis for the industry, yet keeping the same level of accuracy at the area of study (AOS). The model is comprised of overall and nested domains. The overall model domain includes portion of Atlantic Ocean, Delaware, and Chesapeake bays. The nested model domain includes Delaware Bay, its floodplain, and portion of the continental shelf. This study is portion of a larger modeling effort to study the impact of low probability hurricanes on sensitive infrastructures located at the coastal zones prone to hurricane activity. The AOS is located on the east bank of Delaware Bay almost 16 miles upstream of its mouth. Model generated wind speed, significant wave height, water surface elevation, and current are calibrated for hurricane Isabel (2003). The model calibration results agreed reasonably well with field observations. Furthermore, sensitivity of surge and wave responses to various hurricane parameters was tested. In line with findings from other researchers, accuracy of wind field played a major role in hindcasting the hurricane attributes.

San Antonio-Espiritu Santo Bay, Texas Four band, 1meter resolution, UltraCam orthoimage

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Office for Coastal Management purchased digital Vexcel Ultracam imagery and digital elevation models of the Texas coastline at Espiritu-Santo Bay in 2007....

Gulf of Mexico Integrated Science - Tampa Bay Study - Data Information Management System (DIMS)

Science.gov (United States)

Johnston, James

2004-01-01

The Tampa Bay Integrated Science Study is an effort by the U.S. Geological Survey (USGS) that combines the expertise of federal, state and local partners to address some of the most pressing ecological problems of the Tampa Bay estuary. This project serves as a template for the application of integrated research projects in other estuaries in the Gulf of Mexico. Efficient information and data distribution for the Tampa Bay Study has required the development of a Data Information Management System (DIMS). This information system is being used as an outreach management tool, providing information to scientists, decision makers and the public on the coastal resources of the Gulf of Mexico.

Ammonia-oxidizing bacteria and archaea in wastewater treatment plant sludge and nearby coastal sediment in an industrial area in China.

Science.gov (United States)

Zhang, Yan; Chen, Lujun; Sun, Renhua; Dai, Tianjiao; Tian, Jinping; Wen, Donghui

2015-05-01

Under the increasing pressure of human activities, Hangzhou Bay has become one of the most seriously polluted waters along China's coast. Considering the excessive inorganic nitrogen detected in the bay, in this study, the impact of an effluent from a coastal industrial park on ammonia-oxidizing microorganisms (AOMs) of the receiving area was interpreted for the first time by molecular technologies. Revealed by real-time PCR, the ratio of archaeal amoA/bacterial amoA ranged from 5.68 × 10(-6) to 4.79 × 10(-5) in the activated sludge from two wastewater treatment plants (WWTPs) and 0.54-3.44 in the sediments from the effluent receiving coastal area. Analyzed by clone and pyrosequencing libraries, genus Nitrosomonas was the predominant ammonia-oxidizing bacteria (AOB), but no ammonia-oxidizing archaea (AOA) was abundant enough for sequencing in the activated sludge from the WWTPs; genus Nitrosomonas and Nitrosopumilus were the dominant AOB and AOA, respectively, in the coastal sediments. The different abundance of AOA but similar structure of AOB between the WWTPs and nearby coastal area probably indicated an anthropogenic impact on the microbial ecology in Hangzhou Bay.

Single-beam bathymetry data collected in 2015 from Grand Bay, Alabama-Mississippi

Science.gov (United States)

DeWitt, Nancy T.; Stalk, Chelsea A.; Smith, Christopher G.; Locker, Stanley D.; Fredericks, Jake J.; McCloskey, Terrence A.; Wheaton, Cathryn J.

2017-12-01

As part of the Sea-level and Storm Impacts on Estuarine Environments and Shorelines (SSIEES) project, scientists from the U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center conducted a single-beam bathymetry survey within the estuarine, open-bay, and tidal creek environments of Grand Bay, Alabama-Mississippi, from May to June 2015. The goal of the SSIEES project is to assess the physical controls of sediment and material exchange between wetlands and estuarine environments along the northern Gulf of Mexico, specifically Grand Bay, Alabama-Mississippi; Vermilion Bay, Louisiana; and, along the east coast, within Chincoteague Bay, Virginia-Maryland. The data described in this report provide baseline bathymetric information for future research investigating wetland-marsh evolution, sediment transport, erosion, recent and long-term geomorphic change, and can also support the modeling of changes in response to restoration and storm impacts. The survey area encompasses more than 40 square kilometers of Grand Bay’s waters.

Spatial distribution of fallout 137Cs in coastal marine water of Tamil Nadu coast

International Nuclear Information System (INIS)

Hemalatha, P.; Rajaram, S.; Lenka, P.; Jha, S.K.; Puranik, V.D.

2010-01-01

Very little information on the fallout 137 Cs activity exists for the Bay of Bengal. Normally the volume of sea water required for detecting fall out level of 137 Cs in coastal marine environment ranges from 100 litres to 1000 litres. The studies on distribution of 137 Cs in surface seawater of Tamil Nadu in Bay of Bengal were carried out in April 2009. On the eastern coastal lines of Bay of Bengal in Tamil Nadu, seven offshore locations were selected namely Chennai, Pondicherry, Karaikal, Rameshwaram, Tuticorin, Nagercoil and Kanyakumari. In situ preconcentration method was adopted and the experiments were carried out using motor boats well equipped to carry the instruments and provide power supply to operate the pump. 1000 litres of seawater was passed each time through CFCN filters at all the locations at a flow rate of 8 litres per minute. The activity concentrations of 137 Cs was in the range of 0.90 to 2.2 Bq/m 3 . These data represents reference values for coastal environment of Tamil Nadu and will be used to estimate radionuclide inventory in Indian marine environment, particularly of East Coast. The 137 Cs activity indicates that there are no new inputs of these radionuclides into the area. (author)

Nutrient inputs through submarine groundwater discharge in an embayment: A radon investigation in Daya Bay, China

Science.gov (United States)

Wang, Xuejing; Li, Hailong; Yang, Jinzhong; Zheng, Chunmiao; Zhang, Yan; An, An; Zhang, Meng; Xiao, Kai

2017-08-01

Daya Bay, a semi-closed bay of the South China Sea, is famous for its aquaculture, agriculture and tourism. Although routine environmental investigations in the bay have been conducted since the early 1980s, evaluations of submarine groundwater discharge (SGD), an important process in exchange between groundwater and coastal seawater, and its environmental impacts have never been reported. In this study, naturally occurring radon isotope (222Rn) was measured continuously at two sites (north-west and middle-east sites) and used as a tracer to estimate SGD and associated nutrient inputs into the bay. The SGD rates estimated based on the 222Rn mass balance model were, on average, 28.2 cm/d at north-west site and 30.9 cm/d at middle-east site. The large SGD rate at middle-east site may be due to the large tidal amplitude and the sandy component with high permeability in sediments. The SGD-driven nutrient fluxes, which were calculated as the product of SGD flux and the difference of nutrient concentrations between coastal groundwater and seawater, were 3.28 × 105 mol/d for dissolved nitrates (NO3-N), 5.84 × 103 mol/d for dissolved inorganic phosphorous (DIP), and 8.97 × 105 mol/d for reactive silicate (Si). These nutrient inputs are comparable to or even higher than those supplied by local rivers. In addition, these SGD-driven nutrients have a nitrogen-phosphorous ratio as high as ∼43, which may significantly affect the ecology of coastal waters and lead to frequent occurrence of harmful algal blooms.

The Effect of Dissolved Polyunsaturated Aldehydes on Microzooplankton Growth Rates in the Chesapeake Bay and Atlantic Coastal Waters

Directory of Open Access Journals (Sweden)

Peter J. Lavrentyev

2015-05-01

Full Text Available Allelopathy is wide spread among marine phytoplankton, including diatoms, which can produce cytotoxic secondary metabolites such as polyunsaturated aldehydes (PUA. Most studies on diatom-produced PUA have been dedicated to their inhibitory effects on reproduction and development of marine invertebrates. However, little information exists on their impact on key herbivores in the ocean, microzooplankton. This study examined the effects of dissolved 2E,4E-octadienal and 2E,4E-heptadienal on the growth rates of natural ciliate and dinoflagellate populations in the Chesapeake Bay and the coastal Atlantic waters. The overall effect of PUA on microzooplankton growth was negative, especially at the higher concentrations, but there were pronounced differences in response among common planktonic species. For example, the growth of Codonella sp., Leegaardiella sol, Prorodon sp., and Gyrodinium spirale was impaired at 2 nM, whereas Strombidium conicum, Cyclotrichium gigas, and Gymnodinium sp. were not affected even at 20 nM. These results indicate that PUA can induce changes in microzooplankton dynamics and species composition.

The Effect of Dissolved Polyunsaturated Aldehydes on Microzooplankton Growth Rates in the Chesapeake Bay and Atlantic Coastal Waters

Science.gov (United States)

Lavrentyev, Peter J.; Franzè, Gayantonia; Pierson, James J.; Stoecker, Diane K.

2015-01-01

Allelopathy is wide spread among marine phytoplankton, including diatoms, which can produce cytotoxic secondary metabolites such as polyunsaturated aldehydes (PUA). Most studies on diatom-produced PUA have been dedicated to their inhibitory effects on reproduction and development of marine invertebrates. However, little information exists on their impact on key herbivores in the ocean, microzooplankton. This study examined the effects of dissolved 2E,4E-octadienal and 2E,4E-heptadienal on the growth rates of natural ciliate and dinoflagellate populations in the Chesapeake Bay and the coastal Atlantic waters. The overall effect of PUA on microzooplankton growth was negative, especially at the higher concentrations, but there were pronounced differences in response among common planktonic species. For example, the growth of Codonella sp., Leegaardiella sol, Prorodon sp., and Gyrodinium spirale was impaired at 2 nM, whereas Strombidium conicum, Cyclotrichium gigas, and Gymnodinium sp. were not affected even at 20 nM. These results indicate that PUA can induce changes in microzooplankton dynamics and species composition. PMID:25955757

Cd and Pb Concentrations in the Surface Sediments of the Asaluyeh Bay, Iran

Directory of Open Access Journals (Sweden)

Mansooreh Dehghani

2014-06-01

Conclusion: Therefore, it is essential to use abatement efforts to clean-up the polluted areas in the coastal area of the Asaluyeh Bay and prevent the discharging of the untreated or partially treated wastewater to the Persian Gulf as well.

Trace metal dynamics in zooplankton from the Bay of Bengal during summer monsoon

Digital Repository Service at National Institute of Oceanography (India)

Rejomon, G.; DineshKumar, P.K.; Nair, M.; Muraleedharan, K.R.

Trace metal (Fe, Co, Ni, Cu, Zn, Cd, and Pb) concentrations in zooplankton from the mixed layer were investigated at 8 coastal and 20 offshore stations in the western Bay of Bengal during the summer monsoon of 2003. The ecotoxicological importance...

Spatial data quality and coastal spill modelling

International Nuclear Information System (INIS)

Li, Y.; Brimicombe, A.J.; Ralphs, M.P.

1998-01-01

Issues of spatial data quality are central to the whole oil spill modelling process. Both model and data quality performance issues should be considered as indispensable parts of a complete oil spill model specification and testing procedure. This paper presents initial results of research that will emphasise to modeler and manager alike the practical issues of spatial data quality for coastal oil spill modelling. It is centred around a case study of Jiao Zhou Bay in the People's Republic of China. The implications for coastal oil spill modelling are discussed and some strategies for managing the effects of spatial data quality in the outputs of oil spill modelling are explored. (author)

[Microbial Processes and Genesis of Methane Gas Jets in the Coastal Areas of the Crimea Peninsula].

Science.gov (United States)

Malakhova, T V; Kanapatskii, T A; Egorov, V N; Malakhova, L V; Artemov, Yu G; Evtushenko, D B; Gulin, S B; Pimenov, N V

2015-01-01

Hydroasoustic techniques were used for detection and mapping of gas jet areas in the coastal regions of the Crimean peninsula. Gas seep areas in the bays Laspi, Khersones, and Kazach'ya were chosen for detailed microbiological investigation. The first type of gas jets, observed in the Laspi Bay, was probably associated with discarge of deep thermogenic methane along the faults. Methane isotopic composition was char- acterized by Δ13C of -35.3 degrees. While elevated rates of aerobic methane oxidation were revealed in the sandy sediments adjacent to the methane release site, no evidence of bacterial mats was found. The second type of gas emission, observed in the Khersones Bay, was accompanied by formation of bacterial biofilms of the "Thiodendron" microbial community type, predominated by filamentous, spirochete-like organisms, in the areas of gas seepage. The isotopic composition of methane was there considerably lower (-60.4 degrees), indicating a considerable contribution of modern microbial methane to the gas bubbles discharged in this bay. Activity of the third type of gas emission, the seeps of the Kazach'ya Bay, probably depended directly on modern microbial processes of organic matter degradation in the upper sediment layers. The rates of sulfate reduction and methanogenesis were 260 and 34 μmol dm(-3) day(-1), respectively. Our results indicate different mechanisms responsible for formation of methane jets in the Laspi Bay and in the coastal areas of the Heracles Peninsula, where the bays Kazach'ya and Khersones are located.

Bloom dynamics of the genus Pseudo-nitzschia (Bacillariophyceae in two coastal bays (NW Mediterranean Sea

Directory of Open Access Journals (Sweden)

Sonia Quijano-Scheggia

2008-09-01

Full Text Available The spatial and temporal variations in the composition of Pseudo-nitzschia during bloom events from August 2005 to February 2006 were characterised in two bays of the NW Mediterranean Sea (Alfacs and Fangar Bay by means of scanning electron microscopy (SEM. The study provides detailed records of the Pseudo-nitzschia community at the species level and describes its relationship with both the surrounding environmental conditions and biotic factors such as the accompanying phytoplankton community. The size distributions of several species of Pseudo-nitzschia were monitored during the bloom events. These measurements may serve as indicators of the physiological status of the cells. The species observed in the two bays were Pseudo-nitzschia calliantha, P. delicatissima, P. fraudulenta, P. multistriata, and P. pungens. In Alfacs Bay, a mixed species bloom of P. calliantha and P. delicatissima began in late August 2005 and lasted 11 weeks. In Fangar Bay, the Pseudo-nitzschia bloom was limited to the period from early August to late September 2005 and comprised P. calliantha and P. delicatissima. Commonly, the proliferation of Pseudo-nitzschia was mono-specific or was accompanied by other diatoms. Two objectively defined groups were identified by the statistical analysis in Alfacs bay; the first was made up only of winter samples and the second of summer and autumn samples. The first group was defined by a high concentration of NO3¯ and low concentrations of NH4+, conditions associated with a high abundance of P. delicatissima and a low abundance of P. calliantha. The second group expressed the opposite characteristics. A succession of different blooming species of Pseudo-nitzschia lasting months in Alfacs Bay is described.

Modeling the climatic and subsurface stratigraphy controls on the hydrology of a Carolina bay wetland in South Carolina, USA

Science.gov (United States)

Ge Sun; Timothy J. Callahan; Jennifer E. Pyzoha; Carl C. Trettin

2006-01-01

Restoring depressional wetlands or geographically isolated wetlands such as cypress swamps and Carolina bays on the Atlantic Coastal Plains requires a clear understanding of the hydrologic processes and water balances. The objectives of this paper are to (1) test a distributed forest hydrology model, FLATWOODS, for a Carolina bay wetland system using seven years of...

Modeling the climatic and subsurface stratigraphy controls on the hydrology of a Carolina Bay wetland in South Carolina, USA

Science.gov (United States)

Ge Sun; Timothy J. Callahan; Jennifer E. Pyzoha; Carl C. Trettin

2006-01-01

Restoring depressional wetlands or geographically isolated wetlands such as cypress swamps and Carolina bays on the Atlantic Coastal Plains requires a clear understanding of the hydrologic processes and water balances. The objectives of this paper are to (1) test a distributed forest hydrology model, FLATWOODS, for a Carolina bay wetland system using seven years of...

Adjustable Tooling for Bending Brake

Science.gov (United States)

Ellis, J. M.

1986-01-01

Deep metal boxes and other parts easily fabricated. Adjustable tooling jig for bending brake accommodates spacing blocks and either standard male press-brake die or bar die. Holds spacer blocks, press-brake die, bar window die, or combination of three. Typical bending operations include bending of cut metal sheet into box and bending of metal strip into bracket with multiple inward 90 degree bends. By increasing free space available for bending sheet-metal parts jig makes it easier to fabricate such items as deep metal boxes or brackets with right-angle bends.

Distribution of moon jellyfish Aurelia aurita in relation to summer hypoxia in Hiroshima Bay, Seto Inland Sea

Science.gov (United States)

Shoji, Jun; Kudoh, Takaya; Takatsuji, Hideyuki; Kawaguchi, Osamu; Kasai, Akihide

2010-02-01

Biological and physical surveys were conducted in order to investigate the relationship between environmental conditions and the distribution of moon jellyfish Aurelia aurita in Hiroshima Bay, western Seto Inland Sea, Japan. Moon jellyfish and ichthyoplankton were collected at 13 stations in Hiroshima Bay during monthly surveys from July to September in 2006 and 2007. Surface temperature in 2006 was significantly lower during the August and September cruises and surface salinity was lower during all cruises than in 2007. Moon jellyfish was the most dominant gelatinous plankton collected, accounting for 89.7% in wet weight. Mean moon jellyfish abundance in 2006 was higher than that in 2007 from July through September, with significant inter-year differences for July and September. Variability in precipitation and nutritional input from the Ohta River, northernmost part of Hiroshima Bay, were suggested as possible factors affecting the inter-annual variability in moon jellyfish abundance in the coastal areas of northern Hiroshima Bay. Moon jellyfish were more abundant in the coastal areas of northern Hiroshima Bay, where the dissolved oxygen (DO) concentration was lower, while low in the central part of the bay. Japanese anchovy Engraulis japonicus eggs were most dominant (58.1% in number) among the ichthyoplankton and were abundant in the central area of Hiroshima Bay. Explanatory analysis was conducted to detect possible effects of environmental conditions on the abundance of moon jellyfish and Japanese anchovy eggs during the summer months in Hiroshima Bay. Of the environmental conditions tested (temperature, salinity and DO of surface and bottom layers at each sampling station), bottom DO had the most significant effect on the moon jellyfish abundance: there was a negative correlation between the bottom DO and the moon jellyfish abundance in Hiroshima Bay during summer.

A Numerical Study of the Spring-Back Phenomenon in Bending with a Rebar Bending Machine

Directory of Open Access Journals (Sweden)

Chang Hwan Choi

2014-10-01

Full Text Available Recently, the rebar bending methodology started to change from field processing to utilizing rebar bending machines at plant sites prior to transport to the construction locations. Computerized control of rebar plant bending machines provides more accurate and faster bending of rebars than the low quality inefficient field processing alternative. The bending process involves plastic deformation of rebars, where bending stress beyond the yield point of the material is applied. When the bending stress is removed, spring back is caused by the elastic restoring stress. Therefore, an accurate numerical analysis of the spring-back process is required to reduce the bending process errors. The most sensitive factors affecting the spring-back process are the bending radius, the bending angle, the diameter of the rebar, the friction coefficient, and the yielding strength of material. In this paper, we suggest a numerical modeling method using these factors. The finite element modeling of the dynamic mechanical behavior of the material during bending is performed using a commercial dynamic analysis program “DAFUL.” We use the least squares approach to derive the spring-back deflection as a function of the rebar bending parameters.

Nelson River and Hudson Bay

Science.gov (United States)

2002-01-01

Rivers that empty into large bodies of water can have a significant impact on the thawing of nearshore winter ice. This true-color Moderate Resolution Imaging Spectroradiometer (MODIS) image from May 18, 2001, shows the Nelson River emptying spring runoff from the Manitoba province to the south into the southwestern corner of Canada's Hudson Bay. The warmer waters from more southern latitudes hasten melting of ice near the shore, though some still remained, perhaps because in shallow coastal waters, the ice could have been anchored to the bottom. High volumes of sediment in the runoff turned the inflow brown, and the rim of the retreating ice has taken on a dirty appearance even far to the east of the river's entrance into the Bay. The sediment would have further hastened the melting of the ice because its darker color would have absorbed more solar radiation than cleaner, whiter ice. Image courtesy Jacques Descloitres, MODIS Land Rapid Response Team at NASA GSFC

Drivers, trends, and potential impacts of long-term coastal reclamation in China from 1985 to 2010

Energy Technology Data Exchange (ETDEWEB)

Tian, Bo; Wu, Wenting; Yang, Zhaoqing; Zhou, Yunxuan

2016-03-01

Driven by rapid economic development, population growth, and urbanization, China has experienced severe coastal land reclamation over the last decades, which resulted in significant loss of coastal wetland and wildlife habitat, and degradation of marine ecosystems. This study used advanced remote-sensing techniques to analyze the spatial and temporal distributions of coastal reclamation in China and investigated the relationships between coastal land reclamation and coastal economy, population growth, and urbanization. Analysis of long-term Landsat images time series from 1985 to 2010 in 5-year intervals, in combination with remotely sensed image techniques, indicated a sharp increasing trend of land reclamation after 2005, which accounted for over 35% of China’s total reclamation during the 25-year period since 1985. High-intensity coastal reclamation in China was mainly driven by the booming economy associated with urbanization and industrial development in the coastal region. Analysis indicated that coastal land reclamation is closely correlated with the GDP per capita in China. Study results of Landsat images showed that 754,697 ha of coastal wetlands have been reclaimed across all coastal provinces and metropolises from 1985 to 2010, at an annual rate of 5.9%. Coastal areas within the three major economic zones (Bohai Bay, Yangtze River Delta, and Pearl River Delta) were found to generally have higher reclamation rates. For example, the built-up area in Shanghai, which is located in the Yangtze River Delta, increased more than five times from 1985 to 2010. Approximately 35% of the reclamation occurred in Bohai Bay, in which the CRI between 2005 and 2010 was three times higher than the average CRI over the 25-year period.

Phytoplankton community structure in local water types at a coastal site in north-western Bay of Bengal.

Science.gov (United States)

Baliarsingh, S K; Srichandan, Suchismita; Lotliker, Aneesh A; Sahu, K C; Srinivasa Kumar, T

2016-07-01

A comprehensive analysis on seasonal distribution of phytoplankton community structure and their interaction with environmental variables was carried out in two local water types (type 1  30 m isobath) at a coastal site in north-western Bay of Bengal. Phytoplankton community was represented by 211 taxa (146 marine, 37 fresh, 2 brackish, 20 marine-fresh, and 6 marine-brackish-fresh) belonging to seven major groups including 45 potential bloom forming and 22 potential toxin producing species. The seasonal variability depicted enrichment of phytoplankton during pre-monsoon in both water types. Total phytoplankton abundance pattern observed with inter-annual shift during monsoon and post-monsoon period at both water types. In both water types, diatom predominance was observed in terms of species richness and abundance comprising of centric (82 sp.) and pennate (58 sp.) forms. Pennate diatoms, Thalassiothrix longissima and Skeletonema costatum preponderated in both the water types. The diatom abundance was higher in type 1 in comparison to type 2. In general, SiO4 found to fuel growth of the dominant phytoplankton group, diatom in both the water types despite comparative lower concentration of other macronutrients in type 2.

Declining coastal avifauna at a diamond-mining site in Namibia ...

African Journals Online (AJOL)

A review of Namibian shorebird densities over two decades and two additional visits to the coastal diamond-mining areas at Elizabeth Bay, southern Namibia, were undertaken to assess the long-term influence of mining activity on density of shorebirds (Charadrii) and particularly threatened African Black Oystercatchers ...

Seasonal Variation of Colored Dissolved Organic Matter in Barataria Bay, Louisiana, Using Combined Landsat and Field Data

Directory of Open Access Journals (Sweden)

Ishan Joshi

2015-09-01

Full Text Available Coastal bays, such as Barataria Bay, are important transition zones between the terrigenous and marine environments that are also optically complex due to elevated amounts of particulate and dissolved constituents. Monthly field data collected over a period of 15 months in 2010 and 2011 in Barataria Bay were used to develop an empirical band ratio algorithm for the Landsat-5 TM that showed a good correlation with the Colored Dissolved Organic Matter (CDOM absorption coefficient at 355 nm (ag355 (R2 = 0.74. Landsat-derived CDOM maps generally captured the major details of CDOM distribution and seasonal influences, suggesting the potential use of Landsat imagery to monitor biogeochemistry in coastal water environments. An investigation of the seasonal variation in ag355 conducted using Landsat-derived ag355 as well as field data suggested the strong influence of seasonality in the different regions of the bay with the marine end members (lower bay experiencing generally low but highly variable ag355 and the freshwater end members (upper bay experiencing high ag355 with low variability. Barataria Bay experienced a significant increase in ag355 during the freshwater release at the Davis Pond Freshwater Diversion (DPFD following the Deep Water Horizon oil spill in 2010 and following the Mississippi River (MR flood conditions in 2011, resulting in a weak linkage to salinity in comparison to the other seasons. Tree based statistical analysis showed the influence of high river flow conditions, high- and low-pressure systems that appeared to control ag355 by ~28%, 29% and 43% of the time duration over the study period at the marine end member just outside the bay. An analysis of CDOM variability in 2010 revealed the strong influence of the MR in controlling CDOM abundance in the lower bay during the high flow conditions, while strong winds associated with cold fronts significantly increase CDOM abundance in the upper bay, thus revealing the important

Analytic description of the frictionally engaged in-plane bending process incremental swivel bending (ISB)

Science.gov (United States)

Frohn, Peter; Engel, Bernd; Groth, Sebastian

2018-05-01

Kinematic forming processes shape geometries by the process parameters to achieve a more universal process utilizations regarding geometric configurations. The kinematic forming process Incremental Swivel Bending (ISB) bends sheet metal strips or profiles in plane. The sequence for bending an arc increment is composed of the steps clamping, bending, force release and feed. The bending moment is frictionally engaged by two clamping units in a laterally adjustable bending pivot. A minimum clamping force hindering the material from slipping through the clamping units is a crucial criterion to achieve a well-defined incremental arc. Therefore, an analytic description of a singular bent increment is developed in this paper. The bending moment is calculated by the uniaxial stress distribution over the profiles' width depending on the bending pivot's position. By a Coulomb' based friction model, necessary clamping force is described in dependence of friction, offset, dimensions of the clamping tools and strip thickness as well as material parameters. Boundaries for the uniaxial stress calculation are given in dependence of friction, tools' dimensions and strip thickness. The results indicate that changing the bending pivot to an eccentric position significantly affects the process' bending moment and, hence, clamping force, which is given in dependence of yield stress and hardening exponent. FE simulations validate the model with satisfactory accordance.

Closed-form plastic collapse loads of pipe bends under combined pressure and in-plane bending

International Nuclear Information System (INIS)

Oh, Chang Sik; Kim, Yun Jae

2006-01-01

Based on three-dimensional (3-D) FE limit analyses, this paper provides plastic limit, collapse and instability load solutions for pipe bends under combined pressure and in-plane bending. The plastic limit loads are determined from FE limit analyses based on elastic-perfectly plastic materials using the small geometry change option, and the FE limit analyses using the large geometry change option provide plastic collapse loads (using the twice-elastic-slope method) and instability loads. For the bending mode, both closing bending and opening bending are considered, and a wide range of parameters related to the bend geometry is considered. Based on the FE results, closed-form approximations of plastic limit and collapse load solutions for pipe bends under combined pressure and bending are proposed

Early Holocene estuary development of the Hesselø Bay area, southern Kattegat, Denmark and its implication for Ancylus Lake drainage

DEFF Research Database (Denmark)

Bendixen, Carina; Boldreel, Lars Ole; Jensen, Jørn Bo

2017-01-01

environment and a description of coastal processes associated with a river outlet into the bay are presented. Weichselian glacial deposits form the lowermost interpreted unit, covered by late glacial (LG) and postglacial (PG, Holocene) sediments. A funnel-shaped estuary existed at the mouth of channels......High-resolution shallow seismic data, sediment core information, radiocarbon dating and sequence stratigraphy have been used to interpret the late glacial to early Holocene geological evolution of Hesselø Bay in the southern Kattegat, Denmark. A reconstruction of the early Holocene coastal...... in the period 10.3–9.2 cal. ka BP; the channels drained water from south to north. The early PG is characterised by estuarine and coastal deposits. The early Holocene bars that developed in the estuary are preserved as morphological features on the present-day seabed, possibly as a result of rapid relative sea...

Steroid markers to assess sewage and other sources of organic contaminants in surface sediments of Cienfuegos Bay, Cuba.

Science.gov (United States)

Tolosa, I; Mesa, M; Alonso-Hernandez, C M

2014-09-15

Analyses of faecal steroids in coastal sediments from Cienfuegos Bay Cuba indicate chronic sewage contamination at the main outfalls from the city, where concentrations of coprostanol up to 5400ngg(-)(1) (dry wt) were measured. In contrast, steroid concentrations and compositions from sites from the south part of the Bay are characteristic of uncontaminated sewage environments. The levels of coprostanol in the Cienfuegos sediments compares to the lower to mid-range of concentrations reported for coastal sediments on a world-wide basis, with sedimentary levels markedly below those previously reported for heavily impacted sites. This study delivers baseline data for further investigation of the effectiveness of the proposed sewerage plan promoted by the GEF project in Cienfuegos. Investigations on the correlations between faecal steroids and other organic contaminants confirmed that the major source of petroleum hydrocarbons within the bay was associated with the sewage effluents from the Cienfuegos city. Copyright © 2014 Elsevier Ltd. All rights reserved.

Coastal Bend Texas Benthic Habitat Mapping Reprocessed DOQQ Aerial Imagery (NODC Accession 0086051)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — In 2006 and 2007 the NOAA Coastal Services Center purchased services to reprocess existing digital multi-spectral imagery (ADS-40) and create digital benthic habitat...

Cold Bay, Alaska 8 arc-second 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) to support individual coastal States as part of the...

EFFECTS OF HURRICANE IVAN ON WATER QUALITY IN PENSACOLA BAY, FL USA

Science.gov (United States)

Pensacola Bay was in the strong NE quadrant of Hurricane Ivan when it made landfall on September 16, 2004 as a category 3 hurricane on the Saffir-Simpson scale. We present data describing the timeline and maximum height of the storm surge, the extent of flooding of coastal land, ...

Application of organic geochemistry to coastal tar residues from central California

Energy Technology Data Exchange (ETDEWEB)

Kvenvolden, K.A.; Rosenbauer, R.J.; Hostettler, F.D.; Lorenson, T.D.

2000-01-01

Tar residues are common on the Monterey Bay National Marine Sanctuary. These coastal tar residues have been washed ashore and usually occur on headlands near the high-tide line. In this study, 18 coastal tar residues were collected and analyzed to determine their carbon isotopic compositions and values of selected biomarker ratios. All of the residues have very heavy ({sup 13}C-enriched) carbon isotopic compositions spanning a narrow range ({delta}{sup 13}C = {minus}22.2 to {minus}23.4{per{underscore}thousand}), and 28,30-bisnorhopane is present in all samples. These same geochemical characteristics are found in Monterey Formation oils from which the coastal tar residues were likely derived. These coastal residues could result from natural seeps or from accidental spills. Statistically the coastal tar residues can be organized into three groups, each of which may represent different spill or seep events. Seven samples of potential local representative sources for the tar residues were examined, but none could account for the coastal tars.

Temporal and spatial behavior of pharmaceuticals in Narragansett Bay, Rhode Island, United States.

Science.gov (United States)

The behavior and fate of pharmaceutical ingredients in coastal marine ecosystems are not well understood. To address this, the spatial and temporal distribution of 15 high-volume pharmaceuticals were measured over a 1-yr period in Narragansett Bay (RI, USA) to elucidate factors a...

Fate of mercury species in the coastal plume of the Adour River estuary (Bay of Biscay, SW France)

Energy Technology Data Exchange (ETDEWEB)

Sharif, Abubaker; Monperrus, Mathilde; Tessier, Emmanuel; Bouchet, Sylvain; Pinaly, Hervé; Rodriguez-Gonzalez, Pablo [Laboratoire de Chimie Analytique Bio-Inorganique et Environnement, Institut Pluridisciplinaire de Recherche sur l' Environnement et les Matériaux, UMR 5254 CNRS, Université de Pau et des Pays de l' Adour, Hélioparc Pau Pyrénées, 2 av. P. Angot, 64053 Pau cedex 9 (France); Maron, Philippe [Laboratoire des Sciences de l' Ingénieur Appliquées à la Mécanique et au Génie Electrique, Institut Supérieur Aquitain du Bâtiment et des Travaux Publics, Université de Pau et des Pays de l' Adour, Allée du Parc Montaury, 64600 Anglet (France); Amouroux, David, E-mail: david.amouroux@univ-pau.fr [Laboratoire de Chimie Analytique Bio-Inorganique et Environnement, Institut Pluridisciplinaire de Recherche sur l' Environnement et les Matériaux, UMR 5254 CNRS, Université de Pau et des Pays de l' Adour, Hélioparc Pau Pyrénées, 2 av. P. Angot, 64053 Pau cedex 9 (France)

2014-10-15

Because mercury (Hg) undergoes significant biogeochemical processes along the estuarine-coastal continuum, the objective of this work was to investigate the distribution and reactivity of methylmercury (MeHg), inorganic mercury (Hg(II)) and gaseous Hg (DGM) in plume waters of the Adour River estuary (Bay of Biscay). Vertical profiles, spatial and tidal variability of Hg species concentrations were evaluated during two campaigns (April 2007 and May 2010) characterized by significant plume extents over the coastal zone. Incubations with isotopically enriched tracers were performed on bulk and filtered waters under sunlight or dark conditions to investigate processes involved in Hg methylation, demethylation and reduction rates. Total Hg(II) concentrations were more dispersed in April 2007 (5.2 ± 4.9 pM) than in May 2010 (2.5 ± 1.1 pM) while total MeHg concentrations were similar for both seasons and averaged 0.13 ± 0.07 and 0.18 ± 0.11 pM, respectively. DGM concentrations were also similar between the two campaigns, averaging 0.26 ± 0.10 and 0.20 ± 0.09 pM, respectively. Methylation yields remained low within the estuarine plume (< 0.01–0.4% day{sup −1}) while MeHg was efficiently demethylated via both biotic and abiotic pathways (2.3–55.3% day{sup −1}), mainly photo-induced. Hg reduction was also effective in these waters (0.3–43.5% day{sup −1}) and was occurring in both light and dark conditions. The results suggest that the plume is overall a sink for MeHg with integrated net demethylation rates, ranging from 2.0–3.7 g (Hg) d{sup −1}, in the same range than the estimated MeHg inputs from the estuary (respectively, 0.9 and 3.5 g (Hg) d{sup −1}). The large evasion of DGM from the plume waters to the atmosphere (8.8–26.9 g (Hg) d{sup −1}) may also limit Hg{sub T} inputs to coastal waters (33–69 g (Hg) d{sup −1}). These processes are thus considered to be most significant in controlling the fate of Hg transferred from the river to the

Fate of mercury species in the coastal plume of the Adour River estuary (Bay of Biscay, SW France)

International Nuclear Information System (INIS)

Sharif, Abubaker; Monperrus, Mathilde; Tessier, Emmanuel; Bouchet, Sylvain; Pinaly, Hervé; Rodriguez-Gonzalez, Pablo; Maron, Philippe; Amouroux, David

2014-01-01

Because mercury (Hg) undergoes significant biogeochemical processes along the estuarine-coastal continuum, the objective of this work was to investigate the distribution and reactivity of methylmercury (MeHg), inorganic mercury (Hg(II)) and gaseous Hg (DGM) in plume waters of the Adour River estuary (Bay of Biscay). Vertical profiles, spatial and tidal variability of Hg species concentrations were evaluated during two campaigns (April 2007 and May 2010) characterized by significant plume extents over the coastal zone. Incubations with isotopically enriched tracers were performed on bulk and filtered waters under sunlight or dark conditions to investigate processes involved in Hg methylation, demethylation and reduction rates. Total Hg(II) concentrations were more dispersed in April 2007 (5.2 ± 4.9 pM) than in May 2010 (2.5 ± 1.1 pM) while total MeHg concentrations were similar for both seasons and averaged 0.13 ± 0.07 and 0.18 ± 0.11 pM, respectively. DGM concentrations were also similar between the two campaigns, averaging 0.26 ± 0.10 and 0.20 ± 0.09 pM, respectively. Methylation yields remained low within the estuarine plume (< 0.01–0.4% day −1 ) while MeHg was efficiently demethylated via both biotic and abiotic pathways (2.3–55.3% day −1 ), mainly photo-induced. Hg reduction was also effective in these waters (0.3–43.5% day −1 ) and was occurring in both light and dark conditions. The results suggest that the plume is overall a sink for MeHg with integrated net demethylation rates, ranging from 2.0–3.7 g (Hg) d −1 , in the same range than the estimated MeHg inputs from the estuary (respectively, 0.9 and 3.5 g (Hg) d −1 ). The large evasion of DGM from the plume waters to the atmosphere (8.8–26.9 g (Hg) d −1 ) may also limit Hg T inputs to coastal waters (33–69 g (Hg) d −1 ). These processes are thus considered to be most significant in controlling the fate of Hg transferred from the river to the coastal zone. - Highlights: �

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

'It is windier nowadays': Coastal livelihoods and changeable weather in Qeqertarsuaq

DEFF Research Database (Denmark)

Tejsner, Pelle

2012-01-01

This thesis was based on a year-long participant-observer based fieldwork with coastal fishermen and their families on the island of Qeqertarsuaq in Disko Bay, west Greenland. Over the years, Qeqertarsuarmiut have witnessed increasingly stringent whaling quotas and, more recently, a global crisis...

Plastic loads of pipe bends under combined pressure and out-of-plane bending

International Nuclear Information System (INIS)

Lee, Kuk Hee; Kim, Yun Jae; Park, Chi Yong; Lee, Sung Ho; Kim, Tae Ryong

2007-01-01

Based on three-Dimensional (3-D) FE limit analyses, this paper provides plastic limit and TES(Twice- Elastic-Slope) loads for pipe bends under combined pressure and out-of-plane bending. The plastic limit loads are determined from FE limit analyses based on elastic.perfectly-plastic materials using the small geometry change option, and the FE limit analyses using the large geometry change option provide TES plastic loads. A wide range of parameters related to the bend geometry is considered. Based on the FE results, closed-form approximations of plastic limit and TES plastic load solutions for pipe bends under out-of-plane bending are proposed

Holocene coastal paleoenvironmental record, Bay of Brest

Science.gov (United States)

Fernane, Assia; Gandouin, Emmanuel; Goslin, Jérôme; Penaud, Aurélie; Van Vliet lanoë, Brigitte

2013-04-01

Coastal areas are sensitive environments regarding the risk of submersion and the impact on biodiversity induced by salinity changes. These areas thus provide good palaeocecological archives to monitor palaeo sea level changes and the associated adaptation of different biological communities. The north-western coast of France has poorly been investigated regarding its Holocene palaeoecological signatures (Morzadec-Kerfourn, 1974; Naughton et al., 2007). Chironomids have been recognized to be an efficient tool for palaeoclimate and palaeosalinity reconstructions in lakes (Brooks, 2006), and more recently in river floodplains (Gandouin et al, 2006). In this study, environmental changes related to both climate processes and human disturbances, were reconstructed over the last 5000 years, based on pollen and chironomid assemblages from two coastal cores retrieved at Pors Milin (Brittany, NW France). The sedimentary sequences consist of terrestrial peaty layers interdigited with marine clastic deposits. The study area is composed by a sandy beach, truncating the peat, limited by a high sandy bar, and a back marsh developed at + 4 m NGF. Pollen and chironomid results reveal that anthropogenic factors would mainly control environmental changes that occurred in this sector. The disappearance of many chironomid taxa (inhabitants of main river channel) and the dramatic fall in diversity may have been induced by the development of the Merovingian forest clearance at Pors Milin. Indeed, we suggest that the development of agriculture, the river embankment and the draining of wetlands may explain the chironomid habitat loss and the subsequent fall of biodiversity. This change in faunal assemblages occurred synchronously with a decrease in the "arborean / non arborean" pollen ratio reflecting the land opening of the watershed. Several nitrophilous and anthropogenic pollen taxa reinforce our hypothesis concerning the development of agricultural and livestock farming activities at

Lost lake - restoration of a Carolina bay

Energy Technology Data Exchange (ETDEWEB)

Hanlin, H.G.; McLendon, J.P. [Univ. of South Carolina, Aiken, SC (United States). Dept. of Biology and Geology; Wike, L.D. [Univ. of South Carolina, Aiken, SC (United States). Dept. of Biology and Geology]|[Westinghouse Savannah River Co., Aiken, SC (United States). Savannah River Technology Center; Dietsch, B.M. [Univ. of South Carolina, Aiken, SC (United States). Dept. of Biology and Geology]|[Univ. of Georgia, Aiken, SC (United States)

1994-09-01

Carolina bays are shallow wetland depressions found only on the Atlantic Coastal Plain. Although these isolated interstream wetlands support many types of communities, they share the common features of having a sandy margin, a fluctuating water level, an elliptical shape, and a northwest to southeast orientation. Lost Lake, an 11.3 hectare Carolina bay, was ditched and drained for agricultural production before establishment of the Savannah River Site in 1950. Later it received overflow from a seepage basin containing a variety of chemicals, primarily solvents and some heavy metals. In 1990 a plan was developed for the restoration of Lost Lake, and restoration activities were complete by mid-1991. Lost Lake is the first known project designed for the restoration and recovery of a Carolina bay. The bay was divided into eight soil treatment zones, allowing four treatments in duplicate. Each of the eight zones was planted with eight species of native wetland plants. Recolonization of the bay by amphibians and reptiles is being evaluated by using drift fences with pitfall traps and coverboard arrays in each of the treatment zones. Additional drift fences in five upland habitats were also established. Hoop turtle traps, funnel minnow traps, and dip nets were utilized for aquatic sampling. The presence of 43 species common to the region has been documented at Lost Lake. More than one-third of these species show evidence of breeding populations being established. Three species found prior to the restoration activity and a number of species common to undisturbed Carolina bays were not encountered. Colonization by additional species is anticipated as the wetland undergoes further succession.

Some atmospheric dispersion, wind and temperature statistics from Jervis Bay, Australian Capital Territory 1972 to 1974

International Nuclear Information System (INIS)

Clark, G.H.

1985-07-01

A meteorological study of winds, temperatures and Pasquill stability categories was conducted in the coastal conditions at Jervis Bay. Three Pasquill stability categorisation schemes were compared. These indicated a predominance of neutral to slightly unstable conditions. During the daytime, north bay breezes and north-east sea breezes were most common together with on-shore south-east winds. Off-shore south-west winds prevailed during winter and were observed most frequently at night

Topobathymetric elevation model development using a new methodology: Coastal National Elevation Database

Science.gov (United States)

Danielson, Jeffrey J.; Poppenga, Sandra K.; Brock, John C.; Evans, Gayla A.; Tyler, Dean; Gesch, Dean B.; Thatcher, Cindy A.; Barras, John

2016-01-01

During the coming decades, coastlines will respond to widely predicted sea-level rise, storm surge, and coastalinundation flooding from disastrous events. Because physical processes in coastal environments are controlled by the geomorphology of over-the-land topography and underwater bathymetry, many applications of geospatial data in coastal environments require detailed knowledge of the near-shore topography and bathymetry. In this paper, an updated methodology used by the U.S. Geological Survey Coastal National Elevation Database (CoNED) Applications Project is presented for developing coastal topobathymetric elevation models (TBDEMs) from multiple topographic data sources with adjacent intertidal topobathymetric and offshore bathymetric sources to generate seamlessly integrated TBDEMs. This repeatable, updatable, and logically consistent methodology assimilates topographic data (land elevation) and bathymetry (water depth) into a seamless coastal elevation model. Within the overarching framework, vertical datum transformations are standardized in a workflow that interweaves spatially consistent interpolation (gridding) techniques with a land/water boundary mask delineation approach. Output gridded raster TBDEMs are stacked into a file storage system of mosaic datasets within an Esri ArcGIS geodatabase for efficient updating while maintaining current and updated spatially referenced metadata. Topobathymetric data provide a required seamless elevation product for several science application studies, such as shoreline delineation, coastal inundation mapping, sediment-transport, sea-level rise, storm surge models, and tsunami impact assessment. These detailed coastal elevation data are critical to depict regions prone to climate change impacts and are essential to planners and managers responsible for mitigating the associated risks and costs to both human communities and ecosystems. The CoNED methodology approach has been used to construct integrated TBDEM models

Estimates of plastic loads for pipe bends under combined in-plane and out-of-plane bending moment

International Nuclear Information System (INIS)

Kim, Nak Hyun; Oh, Chang Sik; Kim, Yun Jae

2008-01-01

This paper provides a method to estimate plastic loads (defined by twice-elastic-slope) for pipe bends under combined in-plane and out-of-plane bending moment, based on detailed 3-D FE limit analyses using elastic-perfectly plastic materials. Because closing bending moment is always lower than opening bending moment, the combination of in-plane closing bending and out-of-plane bending moment becomes the most significant case. Due to conservatism of each bending moments, the resultant moment provided by ASME B and PV code is unduly conservative. However, the concept of the resultant moment is still valid. In this paper, FE results show that the accurate solutions of bending moments provide better estimates of plastic loads of pipe bend under combined in-plane bending and out-of-plane bending moment

Catchment2Coast: making the link between coastal resource variability and river inputs

CSIR Research Space (South Africa)

Monteiro, P

2003-07-01

Full Text Available groundwater quantity (flow) and quality (nutrients) on mangrove habitat. The development phase will include a literature review on current understanding of groundwater contribu- tions to tropical estuarine and mangrove ecosystems. The model will use...–estuarine hydrodynamics and physical processes in Maputo Bay A validated hydrodynamic modelling system with two-way nesting of the estu- ary, mangrove, bay and coastal system at Maputo will not only facilitate an investi- gation of the influence of river flow...

The dynamics of İzmir Bay under the effects of wind and thermohaline forces

Science.gov (United States)

Sayın, Erdem; Eronat, Canan

2018-04-01

The dominant circulation pattern of İzmir Bay on the Aegean Sea coast of Turkey is studied taking into consideration the influence of wind and thermohaline forces. İzmir Bay is discussed by subdividing the bay into outer, middle and inner areas. Wind is the most important driving force in the İzmir coastal area. There are also thermohaline forces due to the existence of water types of different physical properties in the bay. In contrast to the two-layer stratification during summer, a homogeneous water column exists in winter. The free surface version of the Princeton model (Killworth's 3-D general circulation model) is applied, with the input data obtained through the measurements made by the research vessel K. Piri Reis. As a result of the simulations with artificial wind, the strong consistent wind generates circulation patterns independent of the seasonal stratification in the bay. Wind-driven circulation causes cyclonic or anticyclonic movements in the middle bay where the distinct İzmir Bay Water (IBW) forms. Cyclonic movement takes place under the influence of southerly and westerly winds. On the other hand, northerly and easterly winds cause an anticyclonic movement in the middle bay. The outer and inner bay also have the wind-driven recirculation patterns expected.

Seasonal and interannual study of volatile reduced sulfur compounds (VRSC) in coastal environment: the Bay of Quiberon (Brittany, France)

Science.gov (United States)

Cozic-Houly, A.; Viollier, E.; Sarazin, G.; Knoery, J.

2009-10-01

Seasonal and annual variability of hydrogen sulfide (H2S), carbonyl sulfide (OCS), methane thiol (MeSH), dimethyl sulfide (DMS) and dimethyl disulfide (DMDS) concentrations and supporting parameters (e.g., phytoplanktonic cells abundance) were investigated in a coastal marine environment, the Bay of Quiberon (Brittany, France) from July 2004 to August 2006. The sampling was conducted in the water column, within two meters of the sediment water interface (SWI). Minimum and maximum values were <0.1-1.6 nmol L-1 for H2S, <0.1-4.2 nmol L-1 for OCS, <0.1-7.8 nmol L-1 for MeSH, <0.1-17.5 nmol L-1 for DMS and <0.1-1.7 nmol L-1 for DMDS. Vertical carbonyl sulfide distribution showed seasonal variations with lower concentration near the SWI in winter and bottom enrichments near sediments in summer. Vertical sulfide distribution not seems to be influenced by the shallow sediments. The likely influence of Dinophyceae abundance on the MeSH, DMS and DMDS concentrations was evident for the 3-summer monitored period.

Time series monitoring of water quality and microalgal diversity in a tropical bay under intense anthropogenic interference (SW coast of the Bay of Bengal, India)

Energy Technology Data Exchange (ETDEWEB)

Shaik, Aziz ur Rahman [CSIR — National Institute of Oceanography, Regional Centre, 176 Lawson' s Bay Colony, Visakhapatnam, AP 530017 (India); Biswas, Haimanti, E-mail: haimanti.biswas@nio.org [CSIR — National Institute of Oceanography, Regional Centre, 176 Lawson' s Bay Colony, Visakhapatnam, AP 530017 (India); Reddy, N.P.C.; Srinivasa Rao, V. [CSIR — National Institute of Oceanography, Regional Centre, 176 Lawson' s Bay Colony, Visakhapatnam, AP 530017 (India); Bharathi, M.D. [Present address: ICMAM Project Directorate, 2nd Floor, NIOT Campus, Velacherry-Tambaram Main Road, Pallikkaranai, Chennai 600100 (India); Subbaiah, Ch.V. [CSIR — National Institute of Oceanography, Regional Centre, 176 Lawson' s Bay Colony, Visakhapatnam, AP 530017 (India)

2015-11-15

In recent decades, material fluxes to coastal waters from various land based anthropogenic activities have significantly been enhanced around the globe which can considerably impact the coastal water quality and ecosystem health. Hence, there is a critical need to understand the links between anthropogenic activities in watersheds and its health. Kakinada Bay is situated at the SW part of the Bay of Bengal, near to the second largest mangrove cover in India with several fertilizer industries along its bank and could be highly vulnerable to different types of pollutants. However, virtually, no data is available so far reporting its physicochemical status and microalgal diversity at this bay. In order to fill this gap, we conducted three time series observations at a fixed station during January, December and June 2012, at this bay measuring more than 15 physical, chemical and biological parameters in every 3 h over a period of 36 h in both surface (0 m) and subsurface (4.5 m) waters. Our results clearly depict a strong seasonality between three sampling months; however, any abnormal values of nutrients, biological oxygen demand or dissolved oxygen level was not observed. A Skeletonema costatum bloom was observed in December which was probably influenced by low saline, high turbid and high Si input through the river discharge. Otherwise, smaller diatoms like Thalassiosira decipiens, Thalassiothrix frauenfeldii, and Thalassionema nitzschioides dominated the bay. It is likely that the material loading can be high at the point sources due to intense anthropogenic activities, however, gets diluted with biological, chemical and physical processes in the offshore waters. - Highlights: • No signature of enormous nutrient loading was observed over the diel cycle • Dissolved oxygen and BOD concentrations did not show any exceptional trend • Diatoms dominated more than 90% of the total phytoplankton communities • A Skeletonema Costatum (a centric diatom) bloom was

Time series monitoring of water quality and microalgal diversity in a tropical bay under intense anthropogenic interference (SW coast of the Bay of Bengal, India)

International Nuclear Information System (INIS)

Shaik, Aziz ur Rahman; Biswas, Haimanti; Reddy, N.P.C.; Srinivasa Rao, V.; Bharathi, M.D.; Subbaiah, Ch.V.

2015-01-01

In recent decades, material fluxes to coastal waters from various land based anthropogenic activities have significantly been enhanced around the globe which can considerably impact the coastal water quality and ecosystem health. Hence, there is a critical need to understand the links between anthropogenic activities in watersheds and its health. Kakinada Bay is situated at the SW part of the Bay of Bengal, near to the second largest mangrove cover in India with several fertilizer industries along its bank and could be highly vulnerable to different types of pollutants. However, virtually, no data is available so far reporting its physicochemical status and microalgal diversity at this bay. In order to fill this gap, we conducted three time series observations at a fixed station during January, December and June 2012, at this bay measuring more than 15 physical, chemical and biological parameters in every 3 h over a period of 36 h in both surface (0 m) and subsurface (4.5 m) waters. Our results clearly depict a strong seasonality between three sampling months; however, any abnormal values of nutrients, biological oxygen demand or dissolved oxygen level was not observed. A Skeletonema costatum bloom was observed in December which was probably influenced by low saline, high turbid and high Si input through the river discharge. Otherwise, smaller diatoms like Thalassiosira decipiens, Thalassiothrix frauenfeldii, and Thalassionema nitzschioides dominated the bay. It is likely that the material loading can be high at the point sources due to intense anthropogenic activities, however, gets diluted with biological, chemical and physical processes in the offshore waters. - Highlights: • No signature of enormous nutrient loading was observed over the diel cycle • Dissolved oxygen and BOD concentrations did not show any exceptional trend • Diatoms dominated more than 90% of the total phytoplankton communities • A Skeletonema Costatum (a centric diatom) bloom was

Waste water discharge and its effect on the quality of water of Mahim creek and bay

Digital Repository Service at National Institute of Oceanography (India)

Zingde, M.D.; Desai, B.N.

Coastal environment around Mahim was monitored to evaluate the effects of domestic and industrial waste water discharge in Mahim Creek, Maharashtra, India. Vertical salinity and DO gradient occasionally observed in the Mahim Bay during postmonsoon...

Coral reefs for coastal protection: A new methodological approach and engineering case study in Grenada.

Science.gov (United States)

Reguero, Borja G; Beck, Michael W; Agostini, Vera N; Kramer, Philip; Hancock, Boze

2018-03-15

Coastal communities in tropical environments are at increasing risk from both environmental degradation and climate change and require urgent local adaptation action. Evidences show coral reefs play a critical role in wave attenuation but relatively little direct connection has been drawn between these effects and impacts on shorelines. Reefs are rarely assessed for their coastal protection service and thus not managed for their infrastructure benefits, while widespread damage and degradation continues. This paper presents a systematic approach to assess the protective role of coral reefs and to examine solutions based on the reef's influence on wave propagation patterns. Portions of the shoreline of Grenville Bay, Grenada, have seen acute shoreline erosion and coastal flooding. This paper (i) analyzes the historical changes in the shoreline and the local marine, (ii) assess the role of coral reefs in shoreline positioning through a shoreline equilibrium model first applied to coral reef environments, and (iii) design and begin implementation of a reef-based solution to reduce erosion and flooding. Coastline changes in the bay over the past 6 decades are analyzed from bathymetry and benthic surveys, historical imagery, historical wave and sea level data and modeling of wave dynamics. The analysis shows that, at present, the healthy and well-developed coral reefs system in the southern bay keeps the shoreline in equilibrium and stable, whereas reef degradation in the northern bay is linked with severe coastal erosion. A comparison of wave energy modeling for past bathymetry indicates that degradation of the coral reefs better explains erosion than changes in climate and historical sea level rise. Using this knowledge on how reefs affect the hydrodynamics, a reef restoration solution is designed and studied to ameliorate the coastal erosion and flooding. A characteristic design provides a modular design that can meet specific engineering, ecological and

Shape up or ship out: can we enhance productivity in coastal aquaculture to compete with other uses?

Science.gov (United States)

Schrobback, Peggy; Pascoe, Sean; Coglan, Louisa

2014-01-01

Coastal resources are coming under increasing pressure from competition between recreational, commercial and conservation uses. This is particularly so in coastal areas adjacent to major population centres. Given high recreational and conservation values in such areas, economic activities need to be highly efficient in order to persist. Management of these industries must therefore also encourage efficient production and full utilisation of the areas available. In order to achieve this, managers must first understand the level and drivers of productivity, and how these can be influenced. In this study, by way of illustration, the focus was on the Sydney rock oyster industry within Queensland's Moreton Bay, a multiple use marine park with high recreational and conservation value adjacent to Australia's third largest city. Productivity of the oyster industry in Moreton Bay is currently low compared to historic levels, and management has an objective of reversing this trend. It is unclear whether this difference is due to oyster farmers' business choices and personal characteristics or whether varying environmental conditions in the Moreton Bay limit the capacity of the oyster industry. These require different management responses in order to enhance productivity. The study examined different productivity measures of the oyster industry using data envelopment analysis (DEA) to determine where productivity gains can be made and by how much. The findings suggest that the industry is operating at a high level of capacity utilisation, but a low level of efficiency. The results also suggest that both demographic and environmental conditions affect technical efficiency in the Bay, with water characteristics improvements and appropriate training potentially providing the greatest benefits to the industry. Methods used in this study are transferable to other industries and provide a means by which coastal aquaculture may be managed to ensure it remains competitive with other

Shape up or ship out: can we enhance productivity in coastal aquaculture to compete with other uses?

Directory of Open Access Journals (Sweden)

Peggy Schrobback

Full Text Available Coastal resources are coming under increasing pressure from competition between recreational, commercial and conservation uses. This is particularly so in coastal areas adjacent to major population centres. Given high recreational and conservation values in such areas, economic activities need to be highly efficient in order to persist. Management of these industries must therefore also encourage efficient production and full utilisation of the areas available. In order to achieve this, managers must first understand the level and drivers of productivity, and how these can be influenced. In this study, by way of illustration, the focus was on the Sydney rock oyster industry within Queensland's Moreton Bay, a multiple use marine park with high recreational and conservation value adjacent to Australia's third largest city. Productivity of the oyster industry in Moreton Bay is currently low compared to historic levels, and management has an objective of reversing this trend. It is unclear whether this difference is due to oyster farmers' business choices and personal characteristics or whether varying environmental conditions in the Moreton Bay limit the capacity of the oyster industry. These require different management responses in order to enhance productivity. The study examined different productivity measures of the oyster industry using data envelopment analysis (DEA to determine where productivity gains can be made and by how much. The findings suggest that the industry is operating at a high level of capacity utilisation, but a low level of efficiency. The results also suggest that both demographic and environmental conditions affect technical efficiency in the Bay, with water characteristics improvements and appropriate training potentially providing the greatest benefits to the industry. Methods used in this study are transferable to other industries and provide a means by which coastal aquaculture may be managed to ensure it remains

Tectonic framework of the Hanoe Bay area, southern Baltic Sea

International Nuclear Information System (INIS)

Wannaes, K.O.; Floden, T.

1994-06-01

The tectonic framework and the general geologic development of the Hanoe Bay, from the Scanian coast in the west to south of Oeland in the east, has been investigated by means of reflection seismic methods. The Hanoe Bay is in this paper subdivided into four areas of different geologic settings. These are: 1) The Hanoe Bay slope, which forms a southward dipping continuation of the rigid Blekinge coastal plain. 2) The eastward dipping Kalmarsund Slope, which southwards from Oeland forms the western part of the Paleozoic Baltic Syneclise. 3) The Mesozoic Hanoe Bay Halfgraben, which forms the central and southern parts of the Hanoe Bay. The ongoing subsidence of the Halfgraben is estimated to be in the order of 20-60 m during the Quaternary. 4) The Yoldia Structural Element, which forms a deformed, tilted and possibly rotated block of Paleozoic bedrock located east of the Hanoe Bay Halfgraben. Two tectonic phases dominate the post-Paleozoic development of the Hanoe Bay, these are: 1) The Early Kimmerian phase, which initiated subsidence and reactivated older faults. 2) The Late Cretaceous phase, which is the main subsidence phase of the Hanoe Bay Halfgraben. The tectonic fault pattern of the Hanoe Bay is dominated by three directions, i.e. NW-SE, NE-SW and WNW-ESE. The two main tectonic elements of the area are the Kullen-Christiansoe Ridge System (NW-SE) and the Bornholm Gat Tectonic Zone (NE-SW). Sinistral strike-slip movements in order of 2-3 km are interpreted to have occurred along the Bornholm Gat Tectonic Zone during the late Cretaceous. 20 refs, 19 figs

Early to Middle Holocene sea level fluctuation, coastal progradation and the Neolithic occupation in the Yaojiang Valley of southern Hangzhou Bay, Eastern China

Science.gov (United States)

Liu, Yan; Sun, Qianli; Fan, Daidu; Dai, Bin; Ma, Fuwei; Xu, Lichen; Chen, Jing; Chen, Zhongyuan

2018-06-01

The Yaojiang Valley (YJV) of southern Hangzhou Bay was the birthplace of the well-known Hemudu Culture (HC), one of the representatives of Neolithic civilization in eastern China. To explore the magnitude of natural environmental effects on the HC trajectory, the palaeo-embayment setting of the YJV was studied in detail for the first time in terms of 3D Holocene strata supported by a series of new radiocarbon-dated cores. The results indicated that the local relative sea level rose rapidly during the Early Holocene in the YJV, reached its maximum flooding surface ca. 7900 cal yr BP, and then remained stable ca. 7900-7600 cal yr BP. Thereupon, an estuary stretching inland was first formed by marine transgression, and then, it was transformed to an alluvial-coastal plain by regressive progradation. The alluvial plain was initiated in the foothills and then spread towards the valley centre after sea level stabilization ca. 7600 cal yr BP. Accompanying these natural environmental changes, the earliest arrivals of foragers in the valley occurred no later than ca. 7000 cal yr BP. They engaged in rice farming and fostered the HC for approximately two millennia from ca. 7000-5000 cal yr BP as more lands developed from coastal progradation. The rise and development of the HC are closely associated with the sea level-induced landscape changes in the YJV in the Early-Middle Holocene, but the enigmatic exodus of the HC people after ca. 5000 cal yr BP is still contentious and possibly linked with the rapid waterlogging and deterioration of this setting in such a low-lying coastal plain as well as with associated social reasons.

Eutrophication influence on phytoplankton community composition in three bays on the eastern Adriatic coast

Directory of Open Access Journals (Sweden)

Mia Bužančić

2016-10-01

Full Text Available This study shows the influence of eutrophication pressure on the phytoplankton community structure, abundance and biodiversity in the investigated bays with different hydromorphological features. Šibenik Bay is a highly stratified estuary of the karstic river Krka; Kaštela Bay is a semi-enclosed coastal bay, which is influenced by the relatively small river Jadro; and Mali Ston Bay is located at the Neretva River estuary, the largest river on the eastern part of the Adriatic Sea. All of the areas are affected by urban pressure, which is reflected in the trophic status of the waters. The greatest anthropogenic influence was found in Kaštela Bay while the lowest influence was found in Mali Ston Bay. In this study, the highest biomass concentration and maximum abundance of phytoplankton were recorded at the stations under the strongest anthropogenic influence. Those stations show a dominance of abundance compared to the biomass and a dominance of opportunistic species, which is reflected in the lower biodiversity of phytoplankton community. Diatoms were the most represented group of the phytoplankton community in all three bays, followed by the dinoflagellates. Diatoms that were highlighted as significant for the difference between the bays were Skeletonema marinoi in Šibenik Bay, Leptocylindrus minimus in Kaštela Bay and the genus Chaetoceros spp. in Mali Ston Bay. Dinoflagellates were more abundant at the stations under the strongest anthropogenic influence, and most significant were Prorocentrum triestinum in Kaštela Bay and Gymnodinium spp. in Šibenik Bay and Mali Ston Bay.

Assessment of coastal Strandveld integrity using WorldView-2 imagery in False Bay, South Africa

CSIR Research Space (South Africa)

Lück-Vogel, Melanie

2018-05-01

Full Text Available The coastal zone as interface between land and sea faces much pressure from human activities. These pressures make it difficult for the coastal zones to fulfil their natural functions, so threatening the state of coastal environments and making them...

Finite mixture models for sub-pixel coastal land cover classification

CSIR Research Space (South Africa)

Ritchie, Michaela C

2017-05-01

Full Text Available Models for Sub- pixel Coastal Land Cover Classification M. Ritchie Dr. M. Lück-Vogel Dr. P. Debba Dr. V. Goodall ISRSE - 37 Tshwane, South Africa 10 May 2017 2Study Area Africa South Africa FALSE BAY 3Strand Gordon’s Bay Study Area WorldView-2 Image.../Urban 1 10 10 Herbaceous Vegetation 1 5 5 Shadow 1 8 8 Sparse Vegetation 1 3 3 Water 1 10 10 Woody Vegetation 1 5 5 11 Maximum Likelihood Classification (MLC) 12 Gaussian Mixture Discriminant Analysis (GMDA) 13 A B C t-distribution Mixture Discriminant...

A comparison of the radioactivity levels in the coastal waters between the great wall and Zhongshan stations in Antarctica and the Pohai, Huanghai, east China and south China seas of China

International Nuclear Information System (INIS)

Chen Jinxing

1992-01-01

A comparison of radioactivity levels in the coastal sediments and plants between the Great Wall and Zhongshan Stations in Antarctica and the four seas (i.e. the Pohai Sea, Huanghai Sea, East China Sea and South China Sea) in China shows that in general the radioactivity levels in the coastal sediments and plants in Antarctica are lower than those in the four seas in China. The contents of the total β in the sediments decrease from higher to lower in amount in the order of East China Sea, South China Sea, Pohai Sea, Huanghai Sea and the Great Wall Bay in Antarctica successively, but the contents of 238 U, 232 Th, 226 Ra, 40 K and the total β in marine plants decrease from higher to lower in amount in the order of Daya Bay in the South China Sea, Hanzhou Bay in the East China Sea and the Great Wall Bay in Antarctica successively. The results show that the contamination levels of radioactivity, especially the artificial radioactive contamination in the Antarctic coastal area are far lower than those in China Coastal area, with the remarkable exception of 137 Cs

Recent developments in bend-insensitive and ultra-bend-insensitive fibers

Science.gov (United States)

Boivin, David; de Montmorillon, Louis-Anne; Provost, Lionel; Montaigne, Nelly; Gooijer, Frans; Aldea, Eugen; Jensma, Jaap; Sillard, Pierre

2010-02-01

Designed to overcome the limitations in case of extreme bending conditions, Bend- and Ultra-Bend-Insensitive Fibers (BIFs and UBIFs) appear as ideal solutions for use in FTTH networks and in components, pigtails or patch-cords for ever demanding applications such as military or sensing. Recently, however, questions have been raised concerning the Multi-Path-Interference (MPI) levels in these fibers. Indeed, they are potentially subject to interferences between the fundamental mode and the higher-order mode that is also bend resistant. This MPI is generated because of discrete discontinuities such as staples, bends and splices/connections that occur on distance scales that become comparable to the laser coherent length. In this paper, we will demonstrate the high MPI tolerance of all-solid single-trench-assisted BIFs and UBIFs. We will present the first comprehensive study combining theoretical and experimental points of view to quantify the impact of fusion splices on coherent MPI. To be complete, results for mechanical splices will also be reported. Finally, we will show how the single-trench- assisted concept combined with the versatile PCVD process allows to tightly control the distributions of fibers characteristics. Such controls are needed to massively produce BIFs and to meet the more stringent specifications of the UBIFs.

Land-Use and Land-Cover Change around Mobile Bay, Alabama from 1974-2008

Science.gov (United States)

Ellis, Jean; Spruce, Joseph P.; Swann, Roberta; Smooth, James C.

2009-01-01

This document summarizes the major findings of a Gulf of Mexico Application Pilot project led by NASA Stennis Space Center (SSC) in conjunction with a regional collaboration network of the Gulf of Mexico Alliance (GOMA). NASA researchers processed and analyzed multi-temporal Landsat data to assess land-use and land-cover (LULC) changes in the coastal counties of Mobile and Baldwin, AL between 1974 and 2008. Our goal was to create satellite-based LULC data products using methods that could be transferable to other coastal areas of concern within the Gulf of Mexico. The Mobile Bay National Estuary Program (MBNEP) is the primary end-user, however, several other state and local groups may benefit from the project s data products that will be available through NOAA-NCDDC s Regional Ecosystem Data Management program. Mobile Bay is a critical ecologic and economic region in the Gulf of Mexico and to the entire country. Mobile Bay was designated as an estuary of national significance in 1996. This estuary receives the fourth largest freshwater inflow in the United States. It provides vital nursery habitat for commercially and recreationally important fish species. It has exceptional aquatic and terrestrial bio-diversity, however, its estuary health is influenced by changing LULC patterns, such as urbanization. Mobile and Baldwin counties have experienced a population growth of 1.1% and 20.5% from 2000-2006. Urban expansion and population growth are likely to accelerate with the construction and operation of the ThyssenKrupp steel mill in the northeast portion of Mobile County. Land-use and land-cover change can negatively impact Gulf coast water quality and ecological resources. The conversion of forest to urban cover types impacts the carbon cycle and increases the freshwater and sediment in coastal waters. Increased freshwater runoff decreases salinity and increases the turbidity of coastal waters, thus impacting the growth potential of submerged aquatic vegetation (SAV

Linking climate change mitigation and coastal eutrophication management through biogas technology

DEFF Research Database (Denmark)

Kaspersen, Bjarke Stoltze; Christensen, Thomas Budde; Fredenslund, Anders Michael

2016-01-01

concept for anaerobic co-digestion of food industry residues, manure and beach-cast seaweed has been developed and tested in order to quantify the potential for synergies between climate change mitigation and coastal eutrophication management in the Køge Bay catchment. The biogas plant, currently under...... and phosphorous loads to Køge Bay are estimated to be reduced by approx. 63tyr.-1 and 9tyr.-1, respectively, contributing to the achievement of more than 70% of the nutrient reduction target set for Køge Bay in the first WFD river basin management plan. This study shows that anaerobic co-digestion of the specific...... environment are integrated into the design and decision processes can support the development of this kind of holistic bioenergy solutions....

Hurricane Ike Deposits on the Bolivar Peninsula, Galveston Bay, Texas

Science.gov (United States)

Evans, Cynthia A.; Wilkinson, M. J.; Eppler, Dean

2011-01-01

In September 2008, Hurricane Ike made landfall on Galveston Bay, close to the NASA Johnson Space Center (JSC). The storm flooded much of the area with a storm surge ranging from 11 -20 feet. The Bolivar peninsula, the southeastern coast of Galveston Bay, experienced the brunt of the surge. Several agencies collected excellent imagery baselines before the storm and complementary data a few days afterward that helped define the impacts of the storm. In April of 2011, a team of scientists and astronauts from JSC conducted field mapping exercises along the Bolivar Peninsula, the section of the Galveston Bay coast most impacted by the storm. Astronauts routinely observe and document coastal changes from orbit aboard the International Space Station. As part of their basic Earth Science training, scientists at the Johnson Space Center take astronauts out for field mapping exercises so that they can better recognize and understand features and processes that they will later observe from the International Space Station. Using pre -storm baseline images of the Bolivar Peninsula near Rollover Pass and Gilchrist (NOAA/Google Earth Imagery and USGS aerial imagery and lidar data), the astronauts mapped current coastline positions at defined locations, and related their findings to specific coastal characteristics, including channel, jetties, and other developments. In addition to mapping, we dug trenches along both the Gulf of Mexico coast as well as the Galveston Bay coast of the Bolivar peninsula to determine the depth of the scouring from the storm on the Gulf side, and the amount of deposition of the storm surge deposits on the Bay side of the peninsula. The storm signature was easy to identify by sharp sediment transitions and, in the case of storm deposits, a layer of storm debris (roof shingles, PVC pipes, etc) and black, organic rich layers containing buried sea grasses in areas that were marshes before the storm. The amount of deposition was generally about 20 -25 cm

The Coastal Area Development Using GIS (Review of GIS Application Models

Directory of Open Access Journals (Sweden)

Prastowo Sutanto

2004-01-01

Full Text Available GIS, Geographical Information System, is a means that an be used to plan and to develop the coastal area because in carrying out the analysis this system combines the space data and their  attributes. The activities done among others the prototype development of algae cultivation and tourism ativities, the development of fish pond location, the reclamation of the Jakarta Bay, and the concept of development the floating “Keramba” for pearl oysters and white sea fish similar to sole. GIS analysis with heaviness and overlay mapping yields the appropriate map to plan and to develop the coastal area. The result of GIS analysis can be used to plan and to develop the coastal area.

Applications of MODIS Fluorescence Line Height Measurements to Monitor Water Quality Trends and Algal Bloom Activity in Coastal and Estuarine Waters

Science.gov (United States)

Fischer, A.; Ryan, J. P.; Moreno-Madriñán, M. J.

2012-12-01

Recent advances in satellite and airborne remote sensing, such as improvements in sensor and algorithm calibrations and atmospheric correction procedures have provided for increased coverage of remote-sensing, ocean color products for coastal regions. In particular, for the Moderate Resolution Imaging Spectrometer (MODIS), calibration updates, improved aerosol retrievals, and new aerosol models have led to improved atmospheric correction algorithms for turbid waters and have improved the retrieval of ocean-color. This has opened the way for studying coastal ocean phenomena and processes at finer spatial scales. Human population growth and changes in coastal management practices have brought about significant changes in the concentrations of organic and inorganic, particulate and dissolved substances entering the coastal ocean. There is increasing concern that these inputs have led to declines in water quality and increases in local concentrations of phytoplankton, which could result in harmful algal blooms. In two case studies we present improved and validated MODIS coastal observations of fluorescence line height (FLH) to: (1) assess trends in water quality for Tampa Bay, Florida; and (2) illustrate seasonal and annual variability of algal bloom activity in Monterey Bay, California, as well as document estuarine/riverine plume induced red tide events. In a comprehensive analysis of long term (2003-2011) in situ monitoring data and imagery from Tampa Bay, we assess the validity of the MODIS FLH product against chlorophyll-a and a suite of water quality parameters taken in a variety of conditions throughout this large, optically complex estuarine system. A systematic analysis of sampling sites throughout the bay illustrates that the correlations between FLH and in situ chlorophyll-a are influenced by water quality parameters of total nitrogen, total phosphorous, turbidity and biological oxygen demand. Sites that correlated well with satellite imagery were in depths

Coliform contamination of a coastal embayment: Sources and transport pathways

Science.gov (United States)

Weiskel, P.K.; Howes, B.L.; Heufelder, G.R.

1996-01-01

Fecal bacterial contamination of nearshore waters has direct economic impacts to coastal communities through the loss of shellfisheries and restrictions of recreational uses. We conducted seasonal measurements of fecal coliform (FC) sources and transport pathways contributing to FC contamination of Buttermilk Bay, a shallow embayment adjacent to Buzzards Bay, MA. Typical of most coastal embayments, there were no direct sewage discharges (i.e., outfalls), and fecal bacteria from human, domestic animal, and wildlife pools entered open waters primarily through direct deposition or after transport through surface waters or groundwaters. Direct fecal coliform inputs to bay waters occurred primarily in winter (December-March) from waterfowl, ~33 x 1012 FC yr-1 or ~67% of the total annual loading. Effects of waterfowl inputs on bay FC densities were mitigated by their seasonality, wide distribution across the bay surface, and the apparent limited dispersal from fecal pellets. On-site disposal of sewage by septic systems was the single largest FC source in the watershed-embayment system, 460 x 1012 FC yr-1, but due to attenuation during subsurface transport only a minute fraction, rain events with discharge concentrated in nearshore zones, wet-weather flows were found to have a disproportionately high impact on nearshore FC levels. Elution of FC from shoreline deposits of decaying vegetation (wrack) comprised an additional coliform source. Both laboratory and field experiments suggest significant elution of bacteria from wrack, ~3 x 1012 FC yr-1 on a bay-wide basis (6% of annual input), primarily by periodic tidal flooding and possibly by major rain events. Release of coliforms during resuspension of subtidal sediments was estimated to be a minor source in this system (<1.5 x 1012 FC yr-1 or < 3% of annual input), primarily associated with large storm events in the fall and winter. Based upon the relative source strengths and the spatial and temporal patterns of FC input

Coastal upwelling by wind-driven forcing in Jervis Bay, New South Wales: A numerical study for 2011

Science.gov (United States)

Sun, Youn-Jong; Jalón-Rojas, Isabel; Wang, Xiao Hua; Jiang, Donghui

2018-06-01

The Princeton Ocean Model (POM) was used to investigate an upwelling event in Jervis Bay, New South Wales (SE Australia), with varying wind directions and strengths. The POM was adopted with a downscaling approach for the regional ocean model one-way nested to a global ocean model. The upwelling event was detected from the observed wind data and satellite sea surface temperature images. The validated model reproduced the upwelling event showing the input of bottom cold water driven by wind to the bay, its subsequent deflection to the south, and its outcropping to the surface along the west and south coasts. Nevertheless, the behavior of the bottom water that intruded into the bay varied with different wind directions and strengths. Upwelling-favorable wind directions for flushing efficiency within the bay were ranked in the following order: N (0°; northerly) > NNE (30°; northeasterly) > NW (315°; northwesterly) > NE (45°; northeasterly) > ENE (60°; northeasterly). Increasing wind strengths also enhance cold water penetration and water exchange. It was determined that wind-driven downwelling within the bay, which occurred with NNE, NE and ENE winds, played a key role in blocking the intrusion of the cold water upwelled through the bay entrance. A northerly wind stress higher than 0.3 N m-2 was required for the cold water to reach the northern innermost bay.

STORMTOOLS: Coastal Environmental Risk Index (CERI

Directory of Open Access Journals (Sweden)

Malcolm L. Spaulding

2016-08-01

Full Text Available One of the challenges facing coastal zone managers and municipal planners is the development of an objective, quantitative assessment of the risk to structures, infrastructure, and public safety that coastal communities face from storm surge in the presence of changing climatic conditions, particularly sea level rise and coastal erosion. Here we use state of the art modeling tool (ADCIRC and STWAVE to predict storm surge and wave, combined with shoreline change maps (erosion, and damage functions to construct a Coastal Environmental Risk Index (CERI. Access to the state emergency data base (E-911 provides information on structure characteristics and the ability to perform analyses for individual structures. CERI has been designed as an on line Geographic Information System (GIS based tool, and hence is fully compatible with current flooding maps, including those from FEMA. The basic framework and associated GIS methods can be readily applied to any coastal area. The approach can be used by local and state planners to objectively evaluate different policy options for effectiveness and cost/benefit. In this study, CERI is applied to RI two communities; Charlestown representing a typical coastal barrier system directly exposed to ocean waves and high erosion rates, with predominantly low density single family residences and Warwick located within Narragansett Bay, with more limited wave exposure, lower erosion rates, and higher residential housing density. Results of these applications are highlighted herein.

Occipital bending in schizophrenia.

Science.gov (United States)

Maller, Jerome J; Anderson, Rodney J; Thomson, Richard H; Daskalakis, Zafiris J; Rosenfeld, Jeffrey V; Fitzgerald, Paul B

2017-01-01

To investigate the prevalence of occipital bending (an occipital lobe crossing or twisting across the midline) in subjects with schizophrenia and matched healthy controls. Occipital bending prevalence was investigated in 37 patients with schizophrenia and 44 healthy controls. Ratings showed that prevalence was nearly three times higher among schizophrenia patients (13/37 [35.1%]) than in control subjects (6/44 [13.6%]). Furthermore, those with schizophrenia had greater normalized gray matter volume but less white matter volume and had larger brain-to-cranial ratio. The results suggest that occipital bending is more prevalent among schizophrenia patients than healthy subjects and that schizophrenia patients have different gray matter-white matter proportions. Although the cause and clinical ramifications of occipital bending are unclear, the results infer that occipital bending may be a marker of psychiatric illness.

NOAA Ortho-rectified Mosaic from Color Aerial Imagery of CHOCTAWHATCHEE BAY, FL, 2009 - 2010 (NODC Accession 0086137)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — This data set contains ortho-rectified mosaic tiles, created as a product from the NOAA Integrated Ocean and Coastal Mapping (IOCM) initiative of CHOCTAWHATCHEE BAY....

Using Remotely Sensed Data and Hydrologic Models to Evaluate the Effects of Climate Change on Shallow Aquatic Ecosystems in the Mobile Bay, AL Estuary

Science.gov (United States)

Estes, M. G.; Al-Hamdan, M. Z.; Thom, R.; Judd, C.; Ellis, J.; Woodruff, D.; Quattrochi, D.; Rose, K.; Swann, R.

2012-12-01

Coastal systems in the northern Gulf of Mexico, including the Mobile Bay, AL estuary, are subject to increasing pressure from a variety of activities including climate change. Climate changes have a direct effect on the discharge of rivers that drain into Mobile Bay and adjacent coastal water bodies. The outflows change water quality (temperature, salinity, and sediment concentrations) in the shallow aquatic areas and affect ecosystem functioning. Mobile Bay is a vital ecosystem that provides habitat for many species of fauna and flora. Historically, submerged aquatic vegetation (SAV) and seagrasses were found in this area of the northern Gulf of Mexico; however the extent of vegetation has significantly decreased over the last 60 years. The objectives of this research are to determine: how climate changes affect runoff and water quality in the estuary and how these changes will affect habitat suitability for SAV and seagrasses. Our approach is to use watershed and hydrodynamic modeling to evaluate the impact of climate change on shallow water aquatic ecosystems in Mobile Bay and adjacent coastal areas. Remotely sensed Landsat data were used for current land cover land use (LCLU) model input and the data provided by Intergovernmental Panel on Climate Change (IPCC) of the future changes in temperature, precipitation, and sea level rise were used to create the climate scenarios for the 2025 and 2050 model simulations. Project results are being shared with Gulf coast stakeholders through the Gulf of Mexico Data Atlas to benefit coastal policy and climate change adaptation strategies.

Using Remotely Sensed Data and Hydrologic Models to Evaluate the Effects of Climate Change on Shallow Aquatic Ecosystems in the Mobile Bay, AL Estuary

Science.gov (United States)

Estes, M. G.; Al-Hamdan, M. Z.; Thom, R.; Judd, C.; Woodruff, D.; Ellis, J. T.; Quattrochi, D.; Swann, R.

2012-01-01

Coastal systems in the northern Gulf of Mexico, including the Mobile Bay, AL estuary, are subject to increasing pressure from a variety of activities including climate change. Climate changes have a direct effect on the discharge of rivers that drain into Mobile Bay and adjacent coastal water bodies. The outflows change water quality (temperature, salinity, and sediment concentrations) in the shallow aquatic areas and affect ecosystem functioning. Mobile Bay is a vital ecosystem that provides habitat for many species of fauna and flora. Historically, submerged aquatic vegetation (SAV) and seagrasses were found in this area of the northern Gulf of Mexico; however the extent of vegetation has significantly decreased over the last 60 years. The objectives of this research are to determine: how climate changes affect runoff and water quality in the estuary and how these changes will affect habitat suitability for SAV and seagrasses. Our approach is to use watershed and hydrodynamic modeling to evaluate the impact of climate change on shallow water aquatic ecosystems in Mobile Bay and adjacent coastal areas. Remotely sensed Landsat data were used for current land cover land use (LCLU) model input and the data provided by Intergovernmental Panel on Climate Change (IPCC) of the future changes in temperature, precipitation, and sea level rise were used to create the climate scenarios for the 2025 and 2050 model simulations. Project results are being shared with Gulf coast stakeholders through the Gulf of Mexico Data Atlas to benefit coastal policy and climate change adaptation strategies.

Production and Field Planting of Vegetative Propagules for Restoration of Redhead Grass and Sago Pondweed in Chesapeake Bay

Science.gov (United States)

2009-08-01

submerged aquatic vegetation (SAV) have been lost from shallow waters of Chesapeake Bay (Orth and Moore 1983) and other coastal ecosystems worldwide...a mixture of ambient estuarine water from the Choptank River (a tributary of Chesapeake Bay) and freshwater (tap) needed to maintain a salinity of 7...with a mixture of freshwater and ambient estuarine water (to maintain a salinity of 10) that was circulated through a closed- loop recirculation system

Satellite images survey for the identification of the coastal sedimentary system changes and associated vulnerability along the western bay of the Gulf of Tunis (northern Africa)

Science.gov (United States)

Hzami, Abderraouf; Amrouni, Oula; Romanescu, Gheorghe; Constantin Stoleriu, Cristian; Mihu-Pintilie, Alin; Saâdi, Abdeljaouad

2018-04-01

The aim of this study consists in testing the effectiveness of satellite data in order to monitoring shoreline and sedimentary features changes, especially the rapidly changing of Gulf of Tunis coast. The study area is located in the Gulf of Tunis western bay (Southern Mediterranean Sea) which is characterized by sandy beaches of Ghar Melah and Raoued (Medjerda Delta area). The aerial photographs and satellite imageries were used for mapping the evolution of shoreline. Diachronic data (satellite imagery, aerial photography and topographic maps) were used to monitor and to quantify, the evolution of the coastal areas. These thematic data were digitally overlaid and vectorised for highlighting the shoreline changes between 1936 and 2016, in order to map the rate of erosion and accretion along the shoreline. Results show that the accretion and degradation are related to the Medjerda: change of outlet in 1973 and impoundment of the Sidi Salem dam in 1982. We found that the general trend of the coastal geomorphic processes can be monitored with satellite imageries (such as Sentinel A2, Spots 4 and 5), due to its repetitive coverage along the time and their high quality concerning the spectral contrast between land and sea areas. Improved satellite imageries with high resolution should be a valuable tool for complementing traditional methods for mapping and assessing the sedimentary structures (such as shoreline, delta, marine bars), and monitoring especially the lowlands coastal areas (slightly eroded).

Spatial and temporal trends of short- and medium-chain chlorinated paraffins in sediments off the urbanized coastal zones in China and Japan: A comparison study.

Science.gov (United States)

Zeng, Lixi; Lam, James C W; Horii, Yuichi; Li, Xiaolin; Chen, Weifang; Qiu, Jian-Wen; Leung, Kenneth M Y; Yamazaki, Eriko; Yamashita, Nobuyoshi; Lam, Paul K S

2017-05-01

To examine the impacts of urbanization and industrialization on the coastal environment, and assess the effectiveness of control measures on the contamination by chlorinated paraffins (CPs) in East Asia, surface and core sediments were sampled from the urbanized coastal zones in China and Japan (i.e., Pearl River Delta (PRD), Hong Kong waters and Tokyo Bay) and analyzed for short-chain (SCCPs) and medium-chain CPs (MCCPs). Much higher concentrations of CPs were found in the industrialized PRD than in adjacent Hong Kong waters. Significant correlation between CP concentration and population density in the coastal district of Hong Kong was observed (r 2  = 0.72 for SCCPs and 0.55 for MCCPs, p chain groups within SCCPs in the PRD than in Hong Kong waters and Tokyo Bay implied the effect of industrialization. Comparison of temporal trends between Hong Kong outer harbor with Tokyo Bay shows the striking difference in historical deposition of CPs under different regulatory situations in China and Japan. For the first time, the declining CP concentrations in Tokyo Bay, Japan, attest to the effectiveness of emissions controls. Copyright © 2017 Elsevier Ltd. All rights reserved.

Spatial variation in sediment-water exchange of phosphorus in Florida Bay: AMP as a model organic compound.

Science.gov (United States)

Huang, Xiao-Lan; Zhang, Jia-Zhong

2010-10-15

Dissolved organic phosphorus (DOP) has been recognized as dominant components in total dissolved phosphorus (TDP) pools in many coastal waters, and its exchange between sediment and water is an important process in biogeochemical cycle of phosphorus. Adenosine monophosphate (AMP) was employed as a model DOP compound to simulate phosphorus exchange across sediment-water interface in Florida Bay. The sorption data from 40 stations were fitted to a modified Freundlich equation and provided a detailed spatial distribution both of the sediment's zero equilibrium phosphorus concentration (EPC(0-T)) and of the distribution coefficient (K(d-T)) with respect to TDP. The K(d-T) was found to be a function of the index of phosphorus saturation (IPS), a molar ratio of the surface reactive phosphorus to the surface reactive iron oxide content in the sediment, across the entire bay. However, the EPC(0-T) was found to correlate to the contents of phosphorus in the eastern bay only. Sediment in the western bay might act as a source of the phosphorus in the exchange process due to their high EPC(0-T) and low K(d-T), whereas sediments in the eastern bay might act as a sink because of their low EPC(0-T) and high K(d-T). These results strongly support the hypothesis that both phosphorus and iron species in calcareous marine sediments play a critical role in governing the sediment-water exchange of both phosphate and DOP in the coastal and estuarine ecosystems.

Local and regional scale exchanges of dissolved organic carbon (DOC) between tidal wetlands and their adjacent coastal waters

Science.gov (United States)

Osburn, C. L.; Joshi, I.; Lebrasse, M. C.; Oviedo-Vargas, D.; Bianchi, T. S.; Bohnenstiehl, D. R.; D'Sa, E. J.; He, R.; Ko, D.; Arellano, A.; Ward, N. D.

2017-12-01

The contribution of blue carbon from tidal wetlands to the coastal ocean in the form of dissolved organic carbon (DOC) represents a terrestrial-aquatic linkage of increasing importance. DOC flux results will be presented from local (tidal creek) and regional (bays) scale studies in which various combinations of field observations, ocean-color satellite observations, and the outputs of high-resolution hydrodynamic models were used to estimate DOC export. The first project was located in Bald Head Creek, a tributary to the Cape Fear River estuary in eastern North Carolina (NC). DOC fluxes were computed using a bathymetric data collected via unmanned surface vehicle (USV) and a numerical hydrodynamic model (SCHISM) based on the relationships between colored dissolved organic matter (CDOM) absorption, DOC concentration, and salinity taken from field observations. Model predictions estimated an annual net export of DOC at 54 g C m-2 yr-1 from the tidal creek to the adjacent estuary. Carbon stable isotope (δ13C) values were used to estimate the contribution of wetland carbon to this export. In the second project, DOC fluxes from the Apalachicola Bay, FL, Barataria Bay, LA, were based on the development of algorithms between DOC and CDOM absorption derived from the VIIRS ocean color sensor. The Navy Coastal Ocean Model (NCOM) was used to compute salt flux estimates from each bay to the Louisiana-Texas shelf. The relationship between salinity and CDOM was used to estimate net annual DOC exports of 8.35 x 106 g C m-2 y-1 (Apalachicola Bay) and 7.14 x 106 g C m-2 yr-1 (Barataria Bay). These values approximate 13% and 9% of the annual loads of DOC from the Mississippi River to the Gulf of Mexico, respectively. CDOM and lignin were used in a mixing model to estimate wetland-derived DOC were 2% for Apalachicola Bay and 13% for Barataria Bay, the latter having one of the highest rates of relative sea level rise in North America. Results from our project demonstrated the utility

Relationships between precipitation and surface water chemistry in three Carolina bays

International Nuclear Information System (INIS)

Monegue, R.L.; Jagoe, C.H.

1995-01-01

Carolina Bays are shallow freshwater wetlands, the only naturally occurring lentic systems on the southeastern coastal plain. Bays are breeding sites for many amphibian species, but data on precipitation/surface water relationships and long-term chemical trends are lacking. Such data are essential to interpret major fluctuations in amphibian populations. Surface water and bulk precipitation were sampled bi-weekly for over two years at three bays along a 25 km transect on the Savannah River Site in South Carolina. Precipitation chemistry was similar at all sites; average pH was 4.56, and the major ions were H + (30.8 % of total), and SO 4 (50.3% of total). H + was positively correlated with SO 4 , suggesting the importance of anthropogenic acids to precipitation chemistry. All three bays, Rainbow Bay (RB), Thunder Bay (TB), and Ellenton Bay (EB), contained soft (specific conductivity 5--90 microS/cm), acidic water (pH 4.0--5.9) with DOM from 4--40 mg/L. The major cation for RB, TB, and EB, respectively, was: Mg (30.8 % of total); Na (27% of total); and Ca (34.2% of total). DOM was the major anion for all bays, and SO 4 represented 13 to 28 % of total anions. H + was not correlated to DOM or SO, in RB; H + was positively correlated to DOM and SO 4 in TB, and negatively correlated to DOM and SO 4 in EB. Different biogeochemical processes probably control pH and other chemical variables in each bay. While surface water H + was not directly correlated with precipitation H + , NO 3 , or SO 4 , precipitation and shallow groundwater are dominant water sources for these bays. Atmospheric inputs of anthropogenic acids and other chemicals are important factors influencing bay chemistry

Stormwater impact in Guanabara Bay (Rio de Janeiro): Evidences of seasonal variability in the dynamic of the sediment heavy metals

Science.gov (United States)

Fonseca, E. M.; Baptista Neto, J. A.; Silva, C. G.; McAlister, J. J.; Smith, B. J.; Fernandez, M. A.

2013-09-01

Guanabara Bay is one of the most prominent coastal bays in Brazil. This environment is an estuary of 91 rivers and channels, surrounded by the metropolis of Rio de Janeiro. The bay receives considerable amounts of contaminants introduced from sewage effluents, industrial discharge, urban and agricultural runoff, atmospheric fallout, and the combined inputs from the rivers, making Guanabara Bay one of the most polluted coastal environments on the Brazilian coastline. The aim of this work is to study the concentration and fractionation of the heavy metals within the sediments of the bay. In order to understand the possible seasonal influence on the heavy metal fractionation, two campaigns were carried out in two different seasons of the year (rainy and dry). Twelve stations, in four different areas, with different oceanographic characteristics, where chosen. To assess the bioavailability of the metals a selective extraction procedure was used to study the geochemical fractionation and bioavailability of Zn, Cu, Cr, Ni and Pb. The rainy season was very important with respect to variation in the total concentrations of Cr, Ni and Pb and their fractionation within different "operational" phases present in Guanabara Bay sediments. The water-soluble phase showed little importance, with respect to metal adsorption and this would suggest very low mobility of metals in the water column. Nevertheless, the potentially available metals within these sediments showed a high probability for their release and therefore cause contamination of the water column, since different parts of the bay are constantly subjected to dredging projects promoted by the harbor authorities.

The sediment budget of an urban coastal lagoon (Jamaica Bay, NY) determined using 234Th and 210Pb

Science.gov (United States)

Renfro, Alisha A.; Cochran, J. Kirk; Hirschberg, David J.; Bokuniewicz, Henry J.; Goodbred, Steven L.

2016-10-01

The sediment budget of Jamaica Bay (New York, USA) has been determined using the natural particle-reactive radionuclides 234Th and 210Pb. Inventories of excess thorium-234 (234Thxs, half-life = 24.1 d) were measured in bottom sediments of the Bay during four cruises from September 2004 to July 2006. The mean bay-wide inventory for the four sampling periods ranged from 3.5 to 5.0 dpm cm-2, four to six times that expected from 234Th production in the overlying water column. The presence of dissolved 234Th and a high specific activity of 234Thxs on particles at the bay inlet (∼30 dpm g-1) indicated that both dissolved and particulate 234Th could be imported into the bay from the ocean. Based on these observations, a mass balance of 234Th yields an annual input of ∼39 ± 14 × 1010 g sediment into the bay. Mass accumulation rates determined from profiles of excess 210Pb (half-life = 22.3 y) in sediment cores require annual sediment import of 7.4 ± 4.5 × 1010 g. Both radionuclides indicate that there is considerable marine-derived sediment import to Jamaica Bay, consistent with earlier work using 210Pb. Such sediment input may be important in sustaining longer-term accretion rates of salt marshes in the bay.

Observations and a linear model of water level in an interconnected inlet-bay system

Science.gov (United States)

Aretxabaleta, Alfredo; Ganju, Neil K.; Butman, Bradford; Signell, Richard

2017-01-01

A system of barrier islands and back-barrier bays occurs along southern Long Island, New York, and in many coastal areas worldwide. Characterizing the bay physical response to water level fluctuations is needed to understand flooding during extreme events and evaluate their relation to geomorphological changes. Offshore sea level is one of the main drivers of water level fluctuations in semienclosed back-barrier bays. We analyzed observed water levels (October 2007 to November 2015) and developed analytical models to better understand bay water level along southern Long Island. An increase (∼0.02 m change in 0.17 m amplitude) in the dominant M2 tidal amplitude (containing the largest fraction of the variability) was observed in Great South Bay during mid-2014. The observed changes in both tidal amplitude and bay water level transfer from offshore were related to the dredging of nearby inlets and possibly the changing size of a breach across Fire Island caused by Hurricane Sandy (after December 2012). The bay response was independent of the magnitude of the fluctuations (e.g., storms) at a specific frequency. An analytical model that incorporates bay and inlet dimensions reproduced the observed transfer function in Great South Bay and surrounding areas. The model predicts the transfer function in Moriches and Shinnecock bays where long-term observations were not available. The model is a simplified tool to investigate changes in bay water level and enables the evaluation of future conditions and alternative geomorphological settings.

Atrazine fate and transport within the coastal zone in southeastern Puerto Rico

Science.gov (United States)

Herbicide transport from crop-land to coastal waters may adversely impact water quality. This work examined potential atrazine impact from use on a farm field adjacent to the Jobos Bay National Estuarine Research Reserve on Puerto Rico’s southeastern coast. Atrazine application was linked to residu...

Anthropogenic activities and coastal environmental quality: a regional quantitative analysis in southeast China with management implications.

Science.gov (United States)

Chen, Kai; Liu, Yan; Huang, Dongren; Ke, Hongwei; Chen, Huorong; Zhang, Songbin; Yang, Shengyun; Cai, Minggang

2018-02-01

Regional analysis of environmental issues has always been a hot topic in the field of sustainable development. Because the different levels of economic growth, urbanization, resource endowments, etc. in different regions generate apparently different ecological responses, a better description and comparison across different regions will provide more valuable implications for ecological improvement and policymaking. In this study, seven typical bays in southeast China that are a rapid developing area were selected to quantitatively analyze the relationship between socioeconomic development and coastal environmental quality. Based on the water quality data from 2007 to 2015, the multivariate statistical method was applied to analyze the potential environmental risks and to classify the seven bays based on their environmental quality status. The possible variation trends of environmental indices were predicted based on the cross-regional panel data by Environmental Kuznets Curve. The results showed that there were significant regional differences among the seven bays, especially Quanzhou, Xiamen, and Luoyuan Bays, suffered from severer artificial disturbances than other bays, despite their different development patterns. Socioeconomic development level was significantly associated with some water quality indices (pH, DIN, PO 4 -P); the association was roughly positive: the areas with higher GDP per capita have some worse water quality indices. In addition, the decreasing trend of pH values and the increasing trend of nutrient concentration in the seven bays will continue in the foreseeable future. In consideration of the variation trends, the limiting nutrient strategy should be implemented to mitigate the deterioration of the coastal environments.

Risks for marine coastal ecosystems from anthropogenic loading in the Leningrad NPP environs

International Nuclear Information System (INIS)

Zimina, L.; Zimin, V.; Shchukina, T.; Pomiluiko, G.; Ryabova, V.

1998-01-01

Data on conditions and variations in phytoplankton, zooplankton and fish communities, chlorophyll 'a' and hydrochemical parameters in the coastal waters of Koporskaya Bay (cooling water body of the Leningrad NPP) were analyzed. The most significant anthropogenic factors issued from the Leningrad nuclear power plant activity are of non-radioactive character, as it was recognized during long-time (20 years) ecological monitoring. Main factors influenced ecosystem of the NPP cooling water body are thermal water discharge and nutrient outflows from the bay catchment area. (authors)

DEVELOP Chesapeake Bay Watershed Hydrology - UAV Sensor Web

Science.gov (United States)

Holley, S. D.; Baruah, A.

2008-12-01

The Chesapeake Bay is the largest estuary in the United States, with a watershed extending through six states and the nation's capital. Urbanization and agriculture practices have led to an excess runoff of nutrients and sediment into the bay. Nutrients and sediment loading stimulate the growth of algal blooms associated with various problems including localized dissolved oxygen deficiencies, toxic algal blooms and death of marine life. The Chesapeake Bay Program, among other stakeholder organizations, contributes greatly to the restoration efforts of the Chesapeake Bay. These stakeholders contribute in many ways such as monitoring the water quality, leading clean-up projects, and actively restoring native habitats. The first stage of the DEVELOP Chesapeake Bay Coastal Management project, relating to water quality, contributed to the restoration efforts by introducing NASA satellite-based water quality data products to the stakeholders as a complement to their current monitoring methods. The second stage, to be initiated in the fall 2008 internship term, will focus on the impacts of land cover variability within the Chesapeake Bay Watershed. Multiple student led discussions with members of the Land Cover team at the Chesapeake Bay Program Office in the DEVELOP GSFC 2008 summer term uncovered the need for remote sensing data for hydrological mapping in the watershed. The Chesapeake Bay Program expressed in repeated discussions on Land Cover mapping that significant portions of upper river areas, streams, and the land directly interfacing those waters are not accurately depicted in the watershed model. Without such hydrological mapping correlated with land cover data the model will not be useful in depicting source areas of nutrient loading which has an ecological and economic impact in and around the Chesapeake Bay. The fall 2008 DEVELOP team will examine the use of UAV flown sensors in connection with in-situ and Earth Observation satellite data. To maximize the

Using Remotely Sensed Data and Watershed and Hydrodynamic Models to Evaluate the Effects of Land Cover Land Use Change on Aquatic Ecosystems in Mobile Bay, AL

Science.gov (United States)

Al-Hamdan, Mohammad Z.; Estes, Maurice G., Jr.; Judd, Chaeli; Thom, Ron; Woodruff, Dana; Ellis, Jean T.; Quattrochi, Dale; Watson, Brian; Rodriquez, Hugo; Johnson, Hoyt

2012-01-01

Alabama coastal systems have been subjected to increasing pressure from a variety of activities including urban and rural development, shoreline modifications, industrial activities, and dredging of shipping and navigation channels. The impacts on coastal ecosystems are often observed through the use of indicator species. One such indicator species for aquatic ecosystem health is submerged aquatic vegetation (SAV). Watershed and hydrodynamic modeling has been performed to evaluate the impact of land cover land use (LCLU) change in the two counties surrounding Mobile Bay (Mobile and Baldwin) on SAV stressors and controlling factors (temperature, salinity, and sediment) in the Mobile Bay estuary. Watershed modeling using the Loading Simulation Package in C++ (LSPC) was performed for all watersheds contiguous to Mobile Bay for LCLU scenarios in 1948, 1992, 2001, and 2030. Remotely sensed Landsat-derived National Land Cover Data (NLCD) were used in the 1992 and 2001 simulations after having been reclassified to a common classification scheme. The Prescott Spatial Growth Model was used to project the 2030 LCLU scenario based on current trends. The LSPC model simulations provided output on changes in flow, temperature, and sediment for 22 discharge points into the estuary. These results were inputted in the Environmental Fluid Dynamics Computer Code (EFDC) hydrodynamic model to generate data on changes in temperature, salinity, and sediment on a grid throughout Mobile Bay and adjacent estuaries. The changes in the aquatic ecosystem were used to perform an ecological analysis to evaluate the impact on SAV habitat suitability. This is the key product benefiting the Mobile Bay coastal environmental managers that integrates the influences of temperature, salinity, and sediment due to LCLU driven flow changes with the restoration potential of SAVs. Data products and results are being integrated into NOAA s EcoWatch and Gulf of Mexico Data Atlas online systems for

Study on the cumulative impact of reclamation activities on ecosystem health in coastal waters.

Science.gov (United States)

Shen, Chengcheng; Shi, Honghua; Zheng, Wei; Li, Fen; Peng, Shitao; Ding, Dewen

2016-02-15

The purpose of this study is to develop feasible tools to investigate the cumulative impact of reclamations on coastal ecosystem health, so that the strategies of ecosystem-based management can be applied in the coastal zone. An indicator system and model were proposed to assess the cumulative impact synthetically. Two coastal water bodies, namely Laizhou Bay (LZB) and Tianjin coastal waters (TCW), in the Bohai Sea of China were studied and compared, each in a different phase of reclamations. Case studies showed that the indicator scores of coastal ecosystem health in LZB and TCW were 0.75 and 0.68 out of 1.0, respectively. It can be concluded that coastal reclamations have a historically cumulative effect on benthic environment, whose degree is larger than that on aquatic environment. The ecosystem-based management of coastal reclamations should emphasize the spatially and industrially intensive layout. Copyright © 2015 Elsevier Ltd. All rights reserved.

Comprehensive assessment of coastal eutrophication in Taiwan and its implications for management strategy.

Science.gov (United States)

Liu, Ta-Kang; Chen, Ping; Chen, Hou-Yu

2015-08-15

Due to the rapid population growth, anthropogenic activities result in agricultural, industrial, and urban diffuse runoffs that elevate the level of nutrients such as nitrogen and phosphorus in coastal waters. Currently there is no integrated analysis for coastal eutrophication in Taiwan. A comprehensive analysis of the coastal eutrophic status was performed in this study based on decade-long coastal water quality monitoring data from Taiwan's Environmental Protection Administration. A 3-tiered monitoring strategy is recommended based on the severity of the current eutrophication state. Results indicate that the most problematic area of coastal eutrophication is located in the estuary of the Donggang River (DGR) and its adjacent coastal waters, i.e., the Kao-Ping mouth (KPM) and Dapeng Bay (DPB) in south-western Taiwan. With a worsening eutrophic status, these areas demand intensive monitoring and research with higher spatial and temporal resolutions to evaluate the stresses of nutrient forcing and predict possible future responses. Copyright © 2015 Elsevier Ltd. All rights reserved.

High-precision measurement of tidal current structures using coastal acoustic tomography

Science.gov (United States)

Zhang, Chuanzheng; Zhu, Xiao-Hua; Zhu, Ze-Nan; Liu, Wenhu; Zhang, Zhongzhe; Fan, Xiaopeng; Zhao, Ruixiang; Dong, Menghong; Wang, Min

2017-07-01

A high-precision coastal acoustic tomography (CAT) experiment for reconstructing the current variation in Dalian Bay (DLB) was successfully conducted by 11 coastal acoustic tomography systems during March 7-8, 2015. The horizontal distributions of tidal currents and residual currents were mapped well by the inverse method, which used reciprocal travel time data along 51 successful sound transmission rays. The semi-diurnal tide is dominant in DLB, with a maximum speed of 0.69 m s-1 at the eastern and southwestern parts near the bay mouth that gradually decreases toward the inner bay with an average velocity of 0.31 m s-1. The residual current enters the observational domain from the two flanks of the bay mouth and flows out in the inner bay. One anticyclone and one cyclone were noted inside DLB as was one cyclone at the bay mouth. The maximum residual current in the observational domain reached 0.11 m s-1, with a mean residual current of 0.03 m s-1. The upper 15-m depth-averaged inverse velocities were in excellent agreement with the moored Acoustic Doppler Current Profiler (ADCP) at the center of the bay, with a root-mean-square difference (RMSD) of 0.04 m s-1 for the eastward and northward components. The precision of the present tomography measurements was the highest thus far owing to the largest number of transmission rays ever recorded. Sensitivity experiments showed that the RMSD between CAT and moored-ADCP increased from 0.04 m s-1 to 0.08 m s-1 for both the eastward and northward velocities when reducing the number of transmission rays from 51 to 11. The observational accuracy was determined by the spatial resolution of acoustic ray in the CAT measurements. The cost-optimal scheme consisted of 29 transmission rays with a spatial resolution of acoustic ray of 2.03 √{ km2 / ray numbers } . Moreover, a dynamic analysis of the residual currents showed that the horizontal pressure gradient of residual sea level and Coriolis force contribute 38.3% and 36

Modeling the fate of p,p'-DDT in water and sediment of two typical estuarine bays in South China: Importance of fishing vessels' inputs.

Science.gov (United States)

Fang, Shu-Ming; Zhang, Xianming; Bao, Lian-Jun; Zeng, Eddy Y

2016-05-01

Antifouling paint applied to fishing vessels is the primary source of dichloro-diphenyl-trichloroethane (DDT) to the coastal marine environments of China. With the aim to provide science-based support of potential regulations on DDT use in antifouling paint, we utilized a fugacity-based model to evaluate the fate and impact of p,p'-DDT, the dominant component of DDT mixture, in Daya Bay and Hailing Bay, two typical estuarine bays in South China. The emissions of p,p'-DDT from fishing vessels to the aquatic environments of Hailing Bay and Daya Bay were estimated as 9.3 and 7.7 kg yr(-1), respectively. Uncertainty analysis indicated that the temporal variability of p,p'-DDT was well described by the model if fishing vessels were considered as the only direct source, i.e., fishing vessels should be the dominant source of p,p'-DDT in coastal bay areas of China. Estimated hazard quotients indicated that sediment in Hailing Bay posed high risk to the aquatic system, and it would take at least 21 years to reduce the hazards to a safe level. Moreover, p,p'-DDT tends to migrate from water to sediment in the entire Hailing Bay and Daya Bay. On the other hand, our previous research indicated that p,p'-DDT was more likely to migrate from sediment to water in the maricultured zones located in shallow waters of these two bays, where fishing vessels frequently remain. These findings suggest that relocating mariculture zones to deeper waters would reduce the likelihood of farmed fish contamination by p,p'-DDT. Copyright © 2016 Elsevier Ltd. All rights reserved.

Assessing Drivers of Coastal Primary Production in Northern Marguerite Bay, Antarctica

Directory of Open Access Journals (Sweden)

Patrick D. Rozema

2017-06-01

Full Text Available The coastal ocean of the climatically-sensitive west Antarctic Peninsula is experiencing changes in the physical and (photochemical properties that strongly affect the phytoplankton. Consequently, a shift from diatoms, pivotal in the Antarctic food web, to more mobile and smaller flagellates has been observed. We seek to identify the main drivers behind primary production (PP without any assumptions beforehand to obtain the best possible model of PP. We employed a combination of field measurements and modeling to discern and quantify the influences of variability in physical, (photochemical, and biological parameters on PP in northern Marguerite Bay. Field data of high-temporal resolution (November 2013–March 2014 collected at a long-term monitoring site here were combined with estimates of PP derived from photosynthesis-irradiance incubations and modeled using mechanistic and statistical models. Daily PP varied greatly and averaged 1,764 mg C m−2 d−1 with a maximum of 6,908 mg C m−2 d−1 after the melting of sea ice and the likely release of diatoms concentrated therein. A non-assumptive random forest model (RF with all possibly relevant parameters (MRFmax showed that variability in PP was best explained by light availability and chlorophyll a followed by physical (temperature, mixed layer depth, and salinity and chemical (phosphate, total nitrogen, and silicate water column properties. The predictive power from the relative abundances of diatoms, cryptophytes, and haptophytes (as determined by pigment fingerprinting to PP was minimal. However, the variability in PP due to changes in species composition was most likely underestimated due to the contrasting strategies of these phytoplankton groups as we observed significant negative relations between PP and the relative abundance of flagellates groups. Our reduced model (MRFmin showed how light availability, chlorophyll a, and total nitrogen concentrations can be used to obtain the best

Tampa Bay 1/3 arc-second MHW 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. These integrated...

Respiratory Problems Associated with Surfing in Coastal Waters

OpenAIRE

O Halloran, C; Silver, MW; Lahiff, M; Colford, J

2017-01-01

© 2016, International Association for Ecology and Health. A pilot project was conducted to examine the health status and possible adverse health effects associated with seawater exposure (microbial water-quality indicators and phytoplankton abundance and their toxins) of surfers in Monterey Bay, Central California coastal waters. Forty-eight surfers enrolled in the study and completed an initial health background survey and weekly health surveys online using Survey Monkey. Descriptive statist...

Cold Bay, Alaska 8/15 arc-second 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) to support individual coastal States as part of the...

RoxAnn Acoustic Sensor Data Points - Rehoboth Bay, Delaware Algae Mapping with Single Beam Acoustics: June 12 - 16, 2000

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — During the spring of 1999, the Delaware Coastal Programs(DCP) identified the spatial extent of macroalgae in the shallow portions of Rehoboth Bay utilizing...

Long-term morphologic evolution of the Hangzhou Bay, China

Science.gov (United States)

Wen, W.; Zhijun, D.; Hualiang, X.

2013-12-01

Estuaries are the most productive ecosystems of coastal zones in the world, which are significant to mankind as places of navigation, recreation and commerce as well as extensive and diverse habitats for wildlife. However, most estuary environments in the world had occurred greatly changes in recent decades. These estuaries have suffered from impacts of forcing factors including wave climate, mean sea level change and storm surge, especial to the intensive human activities such as training wall construction, channel dredging, sand mining and dam constructions. Thus, there have been increasing concerns about estuary environment changes under effects of different factors. Riverine loads into the Changjiang Estuary have declined dramatically with the construction of Three Gorges Dam (TGD) in 2003. The morphological evolution of the Hangzhou bay that located the southern proximity of the Yangtze estuary starts to attract increasing attentions due to most material of the Hangzhou bay received from Yangtze estuary. In this paper, historical bathymetric charts were digitized and analyzed within a GIS to provide quantitative estimate of changes in volumes in different regions below 0 m elevation. The results show that Hangzhou bay has experienced a major loss in estuarine volume of about 15% with annual mean sediment deposition rate of 80 million m3/a during the last 75 years. However, there is a large-scale spatial adjustment in Hangzhou bay: Bathymetric changes of the Hangzhou bay can be rapidly shifted within the range of 8-10 classes. Volume of the Jinshanzui upstream of the Hangzhou bay has obviously decreased in the last 75 years, especially during 2003-2008. However, Volume of the southern Hangzhou bay has experienced slowly decrease with minor deposition. The northern Hangzhou bay had largely volume changes with rapidly decrease during 1931-1981, and drastically increase since 2003. Further analysis of the bathymetric data relating to possible factors indicates

Bending the law: tidal bending and its effects on ice viscosity and flow

Science.gov (United States)

Rosier, S.; Gudmundsson, G. H.

2017-12-01

Many ice shelves are subject to strong ocean tides and, in order to accommodate this vertical motion, the ice must bend within the grounding zone. This tidal bending generates large stresses within the ice, changing its effective viscosity. For a confined ice shelf, this is particularly relevant because the tidal bending stresses occur along the sidewalls, which play an important role in the overall flow regime of the ice shelf. Hence, tidal bending stresses will affect both the mean and time-varying components of ice shelf flow. GPS measurements reveal strong variations in horizontal ice shelf velocities at a variety of tidal frequencies. We show, using full-Stokes viscoelastic modelling, that inclusion of tidal bending within the model accounts for much of the observed tidal modulation of horizontal ice shelf flow. Furthermore, our model shows that in the absence of a vertical tidal forcing, the mean flow of the ice shelf is reduced considerably.

Hybrid Wing Body Multi-Bay Test Article Analysis and Assembly Final Report

Science.gov (United States)

Velicki, Alexander; Hoffman, Krishna; Linton, Kim A.; Baraja, Jaime; Wu, Hsi-Yung T.; Thrash, Patrick

2017-01-01

This report summarizes work performed by The Boeing Company, through its Boeing Research & Technology organization located in Huntington Beach, California, under the Environmentally Responsible Aviation (ERA) project. The report documents work performed to structurally analyze and assemble a large-scale Multi-bay Box (MBB) Test Article capable of withstanding bending and internal pressure loadings representative of a Hybrid Wing Body (HWB) aircraft. The work included fabrication of tooling elements for use in the fabrication and assembly of the test article.

Uncovering a New Current: The Southwest MAdagascar Coastal Current

Science.gov (United States)

Ramanantsoa, Juliano D.; Penven, P.; Krug, M.; Gula, J.; Rouault, M.

2018-02-01

Cruise data sets, satellite remote sensing observations, and model data analyses are combined to highlight the existence of a coastal surface poleward flow in the southwest of Madagascar: the Southwest MAdagascar Coastal Current (SMACC). The SMACC is a relatively shallow (water surface signature of the SMACC extends from 22°S (upstream) to 26.4°S (downstream). The SMACC exhibits a seasonal variability: more intense in summer and reduced in winter. The average volume transport of its core is about 1.3 Sv with a mean summer maximum of 2.1 Sv. It is forced by a strong cyclonic wind stress curl associated with the bending of the trade winds along the southern tip of Madagascar. The SMACC directly influences the coastal upwelling regions south of Madagascar. Its existence is likely to influence local fisheries and larval transport patterns, as well as the connectivity with the Agulhas Current, affecting the returning branch of the global overturning circulation.

Distribution and size of the mojarra Diapterus rhombeus (Cuvier) (Actinopterygii, Gerreidae) in a Southeastern Brazilian bay

OpenAIRE

Costa,Marcus Rodrigues da; Albieri,Rafael Jardim; Neves,Leonardo Mitrano; Santos,Alex Braz Lacone; Araujo,Francisco Gerson

2012-01-01

Diapterus rhombeus is one of the most abundant fish species in the Sepetiba bay, which is a 520 km² semi-closed coastal area in Southeastern Brazil. The size and distribution of this species have been described in order to assess the use of the area as a rearing ground in both spatial and temporal (seasonal) dimensions. A fish sampling program was conducted monthly by using an otter trawl between October 1998 and September 1999, in three bay zones (outer, middle and inner), defined according ...

A New Kind of Bend Sensor

Institute of Scientific and Technical Information of China (English)

无

2000-01-01

A new kind of bend sensor is introduced.It can be used to detect the bend angle of an object or inclination between two objects.It has characteristics of small size, lightweight, high reliability, fine flexibility and plasticity.When this bend sensor is used with a proper converting circuit, it can implement dynamic measuring the bend angle of an object conveniently.The application of the bend sensor in dataglove is also described.

Coastal flooding hazard related to storms and coastal evolution in Valdelagrana spit (Cadiz Bay Natural Park, SW Spain)

Science.gov (United States)

Benavente, J.; Del Río, L.; Gracia, F. J.; Martínez-del-Pozo, J. A.

2006-06-01

Mapping of coastal inundation hazard related to storms requires the combination of multiple sources of information regarding meteorological, morphological and dynamic characteristics of both the area at risk and the studied phenomena. Variables such as beach slope, storm wave height or wind speed have traditionally been used, but detailed geomorphological features of the area as well as long-term shoreline evolution trends must also be taken into account in order to achieve more realistic results. This work presents an evaluation of storm flooding hazard in Valdelagrana spit and marshes (SW Spain), considering two types of storm that are characteristic of the area: a modal storm with 1 year of recurrence interval (maximum wave height of 3.3 m), and an extreme storm with 6-10 years of recurrence interval (maximum wave height of 10.6 m), both approaching the coast perpendicularly. After calculating theoretical storm surge elevation, a digital terrain model was made by adjusting topographic data to field work and detailed geomorphological analysis. A model of flooding extent was subsequently developed for each storm type, and then corrected according to the rates of shoreline change in the last decades, which were assessed by means of aerial photographs taking the dune toe as shoreline indicator. Results show that long-term coastline trend represents an important factor in the prediction of flooding extent, since shoreline retreat causes the deterioration of natural coastal defences as dune ridges, thus increasing coastal exposure to high-energy waves. This way, it has been stated that the lack of sedimentary supply plays an important role in spatial variability of inundation extent in Valdelagrana spit. Finally, a hazard map is presented, where calculated coastal retreat rates are employed in order to predict the areas that could be affected by future inundation events.

Discharge of perfluorinated compounds from rivers and their influence on the coastal seas of Hyogo prefecture, Japan

International Nuclear Information System (INIS)

Takemine, Shusuke; Matsumura, Chisato; Yamamoto, Katsuya; Suzuki, Motoharu; Tsurukawa, Masahiro; Imaishi, Hiromasa; Nakano, Takeshi; Kondo, Akira

2014-01-01

The aim of this study was to investigate 12 perfluorinated compounds (PFCs) including perfluorinated carboxylates (C4–C12) and perfluorinated alkyl sulfonates (C4, C6, and C8) in river and seawater samples to determine contamination levels in the aquatic environment of Hyogo prefecture, Japan. High levels of perfluorohexanoic acid (PFHxA; 2300–16,000 ng/L) were detected in the Samondogawa River at Tatsumi Bridge downstream of a PFC production facility; this location also had the highest mass flow rate of PFCs (3900–29,000 kg/y). Widespread contamination of coastal waters was confirmed with PFHxA as the dominant compound. Perfluorooctanoic acid was also prevalent in coastal waters. The concentration of PFHxA in coastal seawater and the distance from the mouth of the Samondogawa River were inversely related. This discharge of high concentrations of PFHxA from the Samondogawa River may have affected concentrations of PFCs in Osaka Bay. -- Highlights: • High perfluorohexanoic acid concentration was detected in the Samondogawa River. • The mass flow rate of PFCs in this river section was 3900–29,000 kg/y. • Perfluorohexanoic acid was the dominant compound at all seawater sampling sites. • Perfluorohexanoic acid from the Samondogawa River may have affected Osaka Bay. -- Discharge of perfluorohexanoic acid from the Samondogawa River may have affected Osaka Bay

Mesozooplankton assemblages in two bays in the Beagle Channel (Argentina during January, 2001

Directory of Open Access Journals (Sweden)

Melisa Daiana Fernández-Severini

2005-12-01

Full Text Available This paper describes the composition and abundance of mesozooplankton of Bahía Ushuaia and Bahía Golondrina. These small bays are located in the northern Beagle Channel. Sampling was carried out from January 20 to 23, 2001 and samples were collected from the upper layer at nine stations. This study is the first research on mesozooplankton in this part of the Beagle Channel. Due to their dominance in the mesozooplankton community, we compared our Copepoda data with those reported by other authors from Antarctic coastal environments. By applying cluster analysis, we found two station groups in both bays: one in slightly polluted zones and the other in undisturbed external zones. Four assemblages in Bahía Ushuaia and two in Bahía Golondrina were determined by using non-metric multidimensional scaling (MDS and cluster analysis. Mesozooplanktonic assemblages showed a certain resemblance in zones with and without anthropogenic influence. Most of the copepod species in our samples are typical of the sub-Antarctic region. Oithona similis (=O. helgolandica sensu Ramírez, 1966, Oncaea curvata, and Ctenocalanus citer show either similar or higher abundances at Antarctic coastal sites, including the upper layer in oceanic areas, in comparison with sub-Antarctic coastal localities. This suggests that, in agreement with other findings, the Polar Front is probably not a major geographic boundary for the distribution of these species.

The creep bending of short radius pipe bends

International Nuclear Information System (INIS)

Spence, John

1975-01-01

In existing and proposed liquid metal fast breeder reactor design the pipework has considerable importance. Parts of the LMFBR include thin walled short radius bends which are expected to operate in the creep regime. In linear elasticity it is known that the assumption of long radius bends is not too severe as far as the flexibility characteristics are concerned although some modifications are necessary for accurate determination of the stresses. No data exists for nonlinear creep. Current work is aimed at elucidating the effect of the various assumptions common to linear elastic theory in so far as they affect the creep characteristics of bends on systems. Herein an energy based analysis using a simple n power constitutive law for stationary creep is employed to derive basic design data for flexibilities and stresses which will be necessary before complete systems can be assessed for creep. The analysis shows on comparison with the long radius work that the assumption of R>r is not much more restrictive in creep than for linear elasticity. Flexibilities for short radius bends appear to be well approximated by the long radius values. Thus the attractive reference stress information already derived may be used directly to find deformations without a complete knowledge of the constitutive relationship. However, stresses are somewhat different. Fortunately the maximum deviation occurs at relatively low levels of stress, the peak stresses being in fair agreement. When n=1 the present results reduce essentially to those obtained from existing linear elastic theory

Coastal Upwelling Drives Intertidal Assemblage Structure and Trophic Ecology.

Science.gov (United States)

Reddin, Carl J; Docmac, Felipe; O'Connor, Nessa E; Bothwell, John H; Harrod, Chris

2015-01-01

Similar environmental driving forces can produce similarity among geographically distant ecosystems. Coastal oceanic upwelling, for example, has been associated with elevated biomass and abundance patterns of certain functional groups, e.g., corticated macroalgae. In the upwelling system of Northern Chile, we examined measures of intertidal macrobenthic composition, structure and trophic ecology across eighteen shores varying in their proximity to two coastal upwelling centres, in a hierarchical sampling design (spatial scales of >1 and >10 km). The influence of coastal upwelling on intertidal communities was confirmed by the stable isotope values (δ13C and δ15N) of consumers, including a dominant suspension feeder, grazers, and their putative resources of POM, epilithic biofilm, and macroalgae. We highlight the utility of muscle δ15N from the suspension feeding mussel, Perumytilus purpuratus, as a proxy for upwelling, supported by satellite data and previous studies. Where possible, we used corrections for broader-scale trends, spatial autocorrelation, ontogenetic dietary shifts and spatial baseline isotopic variation prior to analysis. Our results showed macroalgal assemblage composition, and benthic consumer assemblage structure, varied significantly with the intertidal influence of coastal upwelling, especially contrasting bays and coastal headlands. Coastal topography also separated differences in consumer resource use. This suggested that coastal upwelling, itself driven by coastline topography, influences intertidal communities by advecting nearshore phytoplankton populations offshore and cooling coastal water temperatures. We recommend the isotopic values of benthic organisms, specifically long-lived suspension feeders, as in situ alternatives to offshore measurements of upwelling influence.

Coordinated Field Campaigns in Chesapeake Bay and Gulf of Mexico

Science.gov (United States)

Mannino, Antonio; Novak, Michael; Tzortziou, Maria A.

2015-01-01

NASA's GEOstationary Coastal and Air Pollution Events (GEO-CAPE) mission concept recommended by the U.S. National Research Council (2007) focuses on measurements of atmospheric trace gases and aerosols and aquatic coastal ecology and biogeochemistry from geostationary orbit (35,786 km altitude). Two GEO-CAPE-sponsored multi-investigator ship-based field campaigns were conducted to coincide with the NASA Earth Venture Suborbital project DISCOVER-AQ (Deriving Information on Surface conditions from Column and Vertically Resolved Observations Relevant to Air Quality) field campaigns: (1) Chesapeake Bay in July 2011 and (2) northwestern Gulf of Mexico in September 2013. Goal: to evaluate whether GEO-CAPE coastal mission measurement and instrument requirements are optimized to address science objectives while minimizing ocean color satellite sensor complexity, size and cost - critical mission risk reduction activities. NASA continues to support science studies related to the analysis of data collected as part of these coordinated field campaigns and smaller efforts.

Proceedings of the conference days on 'Climate change impacts on coastal risks'

International Nuclear Information System (INIS)

Becker, M.; Meyssignac, B.; Llovel, W.; Cazenave, A.; Rogel, P.; Woppelmann, G.; Salas y Melia, D.; Morelatto, D.; Benoit, M.; Tiberi-Wadier, A.L.; Charles, E.; Thiebot, J.; Le Cozannet, G.; Pedreros, R.; Ardhuin, F.; Planton, S.; Balouin, Y.; Ferreira, O.; Ciavola, P.; Donato, V.; Walker, P.; Dubois, A.; Sedrati, M.; Menier, D.; Idier, D.; Balouin, Y.; Bohn Bertoldo, R.; Bouchette, F.; Boulahya, F.; Brivois, O.; Calvete, D.; Capo, S.; Castelle, B.; Certain, R.; Charles, E.; Chateauminois, E.; Delvallee, E.; Falques, A.; Fattal, P.; Larroude, P.; Lecacheux, S.; Garnier, R.; Hequette, A.; Maanan, M.; Mallet, C.; Maspataud, A.; Mays, C.; Oliveros, C.; Paillart, M.; Parisot, J.P.; Pedreros, R.; Poumadere, M.; Robin, N.; Ruz, M.H.; Robin, M.; Vinchon, C.; Capo, S.; Rihouey, D.; Howa, H.; Desmazes, F.; Fauque, L.; Maillet, G.; Vella, C.; Pelinovski, E.; Demory, F.; Canut, V.; Dussouillez, P.; Fleury, T.J.; Lecacheux, S.; Garcin, M.; Krien, Y.; Poisson, B.; Almar, R.; Senechal, N.; Bonneton, P.; Ennesser, Y.; Cataliotti, D.; Terrier, M.; Genovese, E.; Hallegatte, S.; Dumas, P.; Sauzeau, T.; Peret, J.; Zaninetti, J.M.; Vinchon, C.; Agenais, A.L.; Baron-Yelles, N.; Berthelier, E.; Garcin, M.; Herivaux, C.; Kuhfuss, L.; Maton, L.; Meur-Ferec, C.; Rey-Valette, H.; Charles, J.C.; Franquart, H.; Hellequin, A.P.; Marche, F.; Mazeiraud, V.; Nathan, F.; Romieu, E.; Rulleau, B.; Maton, L.; Rulleau, B.; Flanquart, H.; Balouin, Y.; Poumadere, M.; Deve, I.; Bouteau, F.; Aubie, S.; Mugica, J.; Hoareau, A.; Duvat, V.; Magnan, A.; Sergent, P.; Prevot, G.; Tissier, M.; Chazel, F.; Lannes, D.; Falques, A.; Ruessink, G.; Maspataud, A.; Ruz, M.H.; Vanhee, S.; Vanroye, C.; Elineau, S.; Duperret, A.; Mallet, P.; Caspar, R.; Bonnot-Courtois, C.; Perherin, C.; Roche, A.; Trmal, C.; Roux, I.; Pons, F.; Boura, C.; Devaux, E.; Desire, G.; Cayocca, F.; Le Hir, P.; Vinchon, C.; Andre, C.; Meur-Ferec, C.; Idier, D.; Rohmer, J.; Turpin, V.; Magnan, A.; Baillarin, F.; Galarraga, D.; Gardel, A.; Fromard, F.; Froidefond, J.M.; Lafon, V.; Proisy, C.; Walcker, R.; Mercier, F.; Pronier, O.; Dehouck, A.; Bertrand, F.; Goeldner-Gianella, L.

2011-01-01

This document gathers the articles of the presentations given during this conference about the climate change impacts on coastal risks: - Topic 1 - forcing changes: Regional sea level changes rebuilt for the last five decades; Sea level modeling in decennial and centennial experiments of the coupled CNRM-CERFACS model; Sea level state simulations in the Atlantic ocean between 1960 and 2100 for 3 climate change scenarios; Wave trends and characteristics variability in the Bay of Biscay from 1958 to 2001; Climate change impacts on storm events affecting the European coastline, the MICORE project; CECILE project: coastal environmental changes, impacts of sea level rise; Hydro-dynamism of a meso-tidal bay-shore in modal conditions and in storm conditions, Suscinio Bay, South-Brittany; - Topic 2 - impacts on unforeseen turns of events: VULSACO - vulnerability of sandy coastal systems in front of climate changes and anthropic pressures, methods, tools, results and lessons learnt; Climate change vulnerability with a 2DH modeling on 4 French beaches; Analysis of the 'Truc-Vert' beach (Gironde) evolution over a decennial period, link with the North Atlantic Oscillation (NAO); Impact of the reduction of the Rhone river solid fraction on the delta coastline mobility since the Little Ice Age; Mega-blocs of the eastern side of the Fos Gulf as markers of exceptional SW-oriented storms; Implementation of a multi-model approach to evaluate the Languedoc coast exposure to marine submersions in a climate change context; Continuous video observation of the littoral: multi-scales and multi-processes; - Topic 3 - Socio-economic impacts: Climate change and coastal risk evaluation in North Africa; Assessment of damage from storm surge and sea level rise to coastal cities: lessons from the Miami area; Construction and environmental protection of centre-west Atlantic coastal communities: contribution of geo-history; Consideration of climate change effects in new coastal protection schemes

Descriptions and preliminary report on sediment cores from the southwest coastal area, Everglades National Park, Florida

Science.gov (United States)

Wingard, G. Lynn; Cronin, Thomas M.; Holmes, Charles W.; Willard, Debra A.; Budet, Carlos A.; Ortiz, Ruth E.

2005-01-01

Sediment cores were collected from five locations in the southwest coastal area of Everglades National Park, Florida, in May 2004 for the purpose of determining the ecosystem history of the area and the impacts of changes in flow through the Shark River Slough. An understanding of natural cycles of change prior to significant human disturbance allows land managers to set realistic performance measures and targets for salinity and other water quality and quantity quality measures. Preliminary examination of the cores indicates significant changes have taken place over the last 1000-2000 years. The cores collected from the inner bays - the most landward bays - are distinctly different from other estuarine sediment cores examined in Florida Bay and Biscayne Bay. Peats in the inner-bay cores from Big Lostmans Bay, Broad River Bay, and Tarpon Bay were deposited at least 1000 years before present (BP) based on radiocarbon analyses. The peats are overlain by poorly sorted organic muds and sands containing species indicative of deposition in a freshwater to very low salinity environment. The Alligator Bay core, the most northern inner-bay core, is almost entirely sand; no detailed faunal analyses or radiometric dating has been completed on this core. The Roberts River core, taken from the mouth of the River where it empties into Whitewater Bay, is lithologically and faunally similar to previously examined cores from Biscayne and Florida Bays; however, the basal unit was deposited ~2000 years before the present based on radiocarbon analyses. A definite trend of increasing salinity over time is seen in the Roberts River core, from sediments representing a terrestrially dominated freshwater environment at the bottom of the core to those representing an estuarine environment with a strong freshwater influence at the top. The changes seen at Roberts River could represent a combination of factors including rising sea-level and changes in freshwater supply, but the timing and

Thresholds of sea-level rise rate and sea-level rise acceleration rate in a vulnerable coastal wetland.

Science.gov (United States)

Wu, Wei; Biber, Patrick; Bethel, Matthew

2017-12-01

Feedbacks among inundation, sediment trapping, and vegetation productivity help maintain coastal wetlands facing sea-level rise (SLR). However, when the SLR rate exceeds a threshold, coastal wetlands can collapse. Understanding the threshold helps address key challenges in ecology-nonlinear response of ecosystems to environmental change, promotes communication between ecologists and resource managers, and facilitates decision-making in climate change policies. We studied the threshold of SLR rate and developed a new threshold of SLR acceleration rate on sustainability of coastal wetlands as SLR is likely to accelerate due to enhanced anthropogenic forces. Deriving these two thresholds depends on the temporal scale, the interaction of SLR with other environmental factors, and landscape metrics, which have not been fully accounted for before this study. We chose a representative marine-dominated estuary in the northern Gulf of Mexico, Grand Bay in Mississippi, to test the concept of SLR thresholds. We developed a mechanistic model to simulate wetland change and then derived the SLR thresholds for Grand Bay. The model results show that the threshold of SLR rate in Grand Bay is 11.9 mm/year for 2050, and it drops to 8.4 mm/year for 2100 using total wetland area as a landscape metric. The corresponding SLR acceleration rate thresholds are 3.02 × 10 -4  m/year 2 and 9.62 × 10 -5  m/year 2 for 2050 and 2100, respectively. The newly developed SLR acceleration rate threshold can help quantify the temporal lag before the rapid decline in wetland area becomes evident after the SLR rate threshold is exceeded, and cumulative SLR a wetland can adapt to under the SLR acceleration scenarios. Based on the thresholds, SLR that will adversely impact the coastal wetlands in Grand Bay by 2100 will fall within the likely range of SLR under a high warming scenario (RCP8.5), highlighting the need to avoid RCP8.5 to preserve these marshes.

Scoping study for coastal slope instability hazard susceptibility : Filey Bay, Beachy Head and Lyme Bay

OpenAIRE

Wildman, G.; Hobbs, P.R.N.

2005-01-01

This report describes the factors that may lead to coastal landslides. It assesses these on a national scale and suggests ways in which they can be incorporated into a landslide potential hazard map for Great Britain. It then details how these factors can be combined in a GIS to produce a digital hazard map in three areas of the country. The results from these test areas are discussed and improvements suggested that might increase the validation of the model.

Foraminiferal record of Holocene paleo-earthquakes on the subsiding south-western Poverty Bay coastline, New Zealand

International Nuclear Information System (INIS)

Hayward, B.W.; Sabaa, A.T.; Grenfell, H.R.; Cochran, U.A.; Clark, K.J.; Litchfield, N.J.; Wallace, L.M.; Marden, M.; Palmer, A.S.

2015-01-01

Foraminiferal faunas in 29 short cores (maximum depth 7 m) of estuarine and coastal wetland sediment were used to reconstruct the middle-late Holocene (last 7 ka) elevational history on the southern shores of Poverty Bay, North Island, New Zealand. This coast is on the southwest side of a rapidly subsiding area beneath western Poverty Bay. Modern Analogue Technique paleo-elevation estimates based on fossil foraminiferal faunas indicate that the four study areas have gradual late Holocene (<3.5 ka) subsidence rates that increase from the southwest (mean c. 0.5 m ka - - 1 ) to northeast (mean c. 1.0 m ka -1 ). Only two rapid, possibly co-seismic, vertical displacement events are recognised: (1) c. 1.2 m of subsidence at 5.7 ± 0.4 ka (cal yr BP), which may have been generated by a subduction interface earthquake centred offshore and recorded in other published studies in northern Hawkes Bay, c. 35 km to the south; and (2) c. 1 m of uplift (relative sea-level fall) at c. 4.5 ± 0.3 ka, which might have been generated by rupture on an offshore upper plate fault that also uplifted coastal terraces at Pakarae and Mahia, 40 km to the north and south of the study area, or by rupture on the subduction interface penetrating beneath Poverty Bay. No sudden displacement events are recognised during the last 4 ka although subsidence, possibly aseismic, has continued. (author).

Historical sediment budget and present-day catchment-shoreline coupling at Twofold Bay, southeastern Australia

Science.gov (United States)

Tamura, T.; Oliver, T.; Hudson, J.; Woodroffe, C. D.

2017-12-01

Considering projected impacts of sea-level rise in the 21st century on sandy shorelines, an understanding of long-term sediment budget for individual beaches or coastal compartments supports assessments of shoreline stability. We examined a low-lying coastal beach-ridge barrier in Twofold Bay using optically stimulated luminescence (OSL) dating , airborne LiDAR, sedimentological analysis and seismic data to assess changes in rates of sediment supply to this shoreline through time. Calculations of barrier volume, Twofold Bay bay-floor sediment volume and estimates of sediment delivery from a proximal river system provide a broad-scale assessment of past-sediment budget. Between ca. 7500 years ago and 1500 years ago, sources of sediment for shoreline progradation at Boydtown were bay-floor sediments either inherited or moved into the embayment during late-stage transgression. Progradation rate between ca. 7500-1500 years ago was 0.16 m/yr with subaerial barrier volume accumulating at 0.46 m3/m/yr. Between ca. 1500 years and present day, the Towamba River to the south has delivered additional sediment to the Boydtown shoreline more than doubling shoreline progradation rate to 0.65 m/yr and subaerial barrier accumulation has risen to 1.83 m3/m/yr. The delivery of fluvial sediment from the Towamba River was restricted to the past ca. 1500 years as prior to this, estuary infilling prevented floods delivering sediments to the bay. This recent historical coupling of river sand supply and shoreline progradation rate implies that anthropogenic modifications to the Towamba River catchment such as river damming, or climatic changes reducing rainfall or runoff, would negatively impact the Boydtown Beach shoreline. Conversely increased rainfall or deforestation may increase sediment discharge due to upstream erosion. The Boydtown shoreline within Twofold Bay may be able to maintain its current position in the coming century if fluvial sediment delivery continues. The fact that

Spatial and seasonal patterns of ichthyoplankton assemblages in the Haizhou Bay and its adjacent waters of China

Science.gov (United States)

Li, Zengguang; Ye, Zhenjiang; Wan, Rong

2015-12-01

Surveys were conducted in five voyages in Haizhou Bay and its adjacent coastal area from March to December 2011 during full moon spring tides. The ichthyoplankton assemblages and the environmental factors that affect their spatial and seasonal patterns were determined. Totally 35 and 12 fish egg and larvae taxa were identified, respectively. Over the past several decades, the egg and larval species composition has significantly changed in Haizhou Bay and its adjacent waters, most likely corresponding with the alteration of fishery resources, which are strongly affected by anthropogenic activities and climate change. The Bray-Curtis dissimilarity index identified four assemblages: near-shore bay assemblage, middle bay assemblage and two closely related assemblages (near-shore/middle bay assemblage and middle/edge of bay assemblage). The primary species of each assemblage principally reflected the spawning strategies of adult fish. The near-shore bay assemblage generally occurred in near-shore bay, with depths measuring ichthyoplankton in each assemblage were determined by interactions between biological behavioral traits and oceanographic features, particularly the variation of local conditions within the constraint of a general reproductive strategy. The results of Spearman's rank correlation analysis indicated that both fish egg and larval abundance were positively correlated with depth, which is critical to the oceanographic features in Haizhou Bay.

Distribution of foraminifera in Chincoteague Bay and the marshes of Assateague Island and the adjacent vicinity, Maryland and Virginia

Science.gov (United States)

Ellis, Alisha M.; Shaw, Jaimie; Osterman, Lisa E.; Smith, Christopher G.

2017-11-28

Scientists from the U.S. Geological Survey (USGS), St. Petersburg Coastal and Marine Science Center conducted a seasonal collection of estuarine, marsh, and sandy washover surface sediments from Chincoteague Bay, Tom’s Cove, and the surrounding Assateague Island and Delmarva Peninsula in March–April and October 2014, after Hurricane Sandy. Micropaleontology samples were collected as part of a complementary USGS Coastal and Marine Geology Program Sea-level and Storm Impacts on Estuarine Environments and Shorelines project study. For comparison with estuarine and overwash deposited foraminifera, a group of scientists from the USGS Woods Hole Coastal and Marine Science Center in Massachusetts collected samples offshore of Assateague Island on the inner continental shelf during a seafloor mapping study in the summer of 2014 and shipped select samples to the St. Petersburg Coastal and Marine Science Center. The micropaleontological subsamples analyzed for foraminifera at each site can be used to establish a foraminiferal baseline assemblage that takes into consideration the seasonal variability of the various species, regarding density and geographic extent, which are influenced by transient and stable environmental parameters. By understanding what parameters affect the various foraminiferal assemblages, researchers can delineate how alterations in salinity, temperature, or marsh-to-bay interactions, such as marsh erosion, might affect that assemblage.

Development of a Hydrodynamic and Transport model of Bellingham Bay in Support of Nearshore Habitat Restoration

Energy Technology Data Exchange (ETDEWEB)

Wang, Taiping; Yang, Zhaoqing; Khangaonkar, Tarang

2010-04-22

In this study, a hydrodynamic model based on the unstructured-grid finite volume coastal ocean model (FVCOM) was developed for Bellingham Bay, Washington. The model simulates water surface elevation, velocity, temperature, and salinity in a three-dimensional domain that covers the entire Bellingham Bay and adjacent water bodies, including Lummi Bay, Samish Bay, Padilla Bay, and Rosario Strait. The model was developed using Pacific Northwest National Laboratory’s high-resolution Puget Sound and Northwest Straits circulation and transport model. A sub-model grid for Bellingham Bay and adjacent coastal waters was extracted from the Puget Sound model and refined in Bellingham Bay using bathymetric light detection and ranging (LIDAR) and river channel cross-section data. The model uses tides, river inflows, and meteorological inputs to predict water surface elevations, currents, salinity, and temperature. A tidal open boundary condition was specified using standard National Oceanic and Atmospheric Administration (NOAA) predictions. Temperature and salinity open boundary conditions were specified based on observed data. Meteorological forcing (wind, solar radiation, and net surface heat flux) was obtained from NOAA real observations and National Center for Environmental Prediction North American Regional Analysis outputs. The model was run in parallel with 48 cores using a time step of 2.5 seconds. It took 18 hours of cpu time to complete 26 days of simulation. The model was calibrated with oceanographic field data for the period of 6/1/2009 to 6/26/2009. These data were collected specifically for the purpose of model development and calibration. They include time series of water-surface elevation, currents, temperature, and salinity as well as temperature and salinity profiles during instrument deployment and retrieval. Comparisons between model predictions and field observations show an overall reasonable agreement in both temporal and spatial scales. Comparisons of

Clusters of community exposure to coastal flooding hazards based on storm and sea level rise scenarios—implications for adaptation networks in the San Francisco Bay region

Science.gov (United States)

Hummel, Michelle; Wood, Nathan J.; Schweikert, Amy; Stacey, Mark T.; Jones, Jeanne; Barnard, Patrick L.; Erikson, Li H.

2018-01-01

Sea level is projected to rise over the coming decades, further increasing the extent of flooding hazards in coastal communities. Efforts to address potential impacts from climate-driven coastal hazards have called for collaboration among communities to strengthen the application of best practices. However, communities currently lack practical tools for identifying potential partner communities based on similar hazard exposure characteristics. This study uses statistical cluster analysis to identify similarities in community exposure to flooding hazards for a suite of sea level rise and storm scenarios. We demonstrate this approach using 63 jurisdictions in the San Francisco Bay region of California (USA) and compare 21 distinct exposure variables related to residents, employees, and structures for six hazard scenario combinations of sea level rise and storms. Results indicate that cluster analysis can provide an effective mechanism for identifying community groupings. Cluster compositions changed based on the selected societal variables and sea level rise scenarios, suggesting that a community could participate in multiple networks to target specific issues or policy interventions. The proposed clustering approach can serve as a data-driven foundation to help communities identify other communities with similar adaptation challenges and to enhance regional efforts that aim to facilitate adaptation planning and investment prioritization.

Relative Sea Level Trends Along the Coast of the Bay of Bengal

Science.gov (United States)

Becker, M.; Calmant, S.; Papa, F.; Delebecque, C.; Islam, A. S.; Shum, C. K.

2016-12-01

In the coastal belt of the Bay of Bengal, the sea level rise is one of a major threat, linked to climate change, which drastically affects the livelihoods of millions of people. A comprehensive understanding of sea level trends and its variability in this region is therefore crucial and should help to anticipate the impacts of climate change and implement adaptation strategies. This region is bordered mostly by Bangladesh, India, Malaysia, Myanmar, and Thailand. Here, we revisit the sea level changes in the Bay of Bengal region from tide gauges and satellite altimetry over the period 1993-2014. The 23 monthly mean tide gauge records, used in this study, are retrieved from PSMSL (15 records) and supplemented with Bangladeshi observations (8 records). We show that, over the satellite altimetry era, the sea level interannual/decadal variability is mainly due to ocean thermal expansion variability driven by IOD/ENSO events and their low frequency modulation. We focus on relative sea level rise at major coastal cities and try to separate the climatic signal (long term trend plus interannual/decadal variability) from local effects, in particular vertical land movements. Results from GPS are analysed where available. When no such data exist, vertical land movements are deduced from the combined use of tide gauge and altimetry data. While the analysis is performed over the whole region, a particular attention is given to the low-lyingBangladesh's coastal area.

Temporal-spatial variations and driving factors analysis of coastal reclamation in China

Science.gov (United States)

Meng, Weiqing; Hu, Beibei; He, Mengxuan; Liu, Baiqiao; Mo, Xunqiang; Li, Hongyuan; Wang, Zhongliang; Zhang, Yu

2017-05-01

Coastal reclamation is the gain of land from the sea or coastal wetlands for agricultural purposes, industrial use or port expansions. Large-scale coastal land reclamation can have adverse effects on the coastal environment, including loss of marine habitats and deterioration of coastal water quality. In recent decades, coastal land reclamation has occurred extensively to meet the increasing needs of rapid economic development and urbanization in China. The overall objective of this study is to understand the coastal reclamation status of China from 1979 to 2014 and analyzed its driving factors for mitigating negative ecological effects. The data of coastal reclamation were done with the ERDAS Imagine V9.2 platform and ArcGIS software based on remote images including Landsat, SPOT, ZY-2 and ZY-3. Potential driving factors for sea reclamation were selected based on statistics bulletins and the knowledge of experts in coastal management. In order to understand the relationships among possible impact factors and coastal reclamation, the Partial Least-Squares Regression models was constructed. The analysis results indicated that the total area of reclamation was 11162.89 km2 based on remote sensing images between 1979 and 2014. Shandong Province is the largest reclamation area, reaching 2736.54 km2, and the reclamation is mainly concentrated in Zhejiang, Jiangsu and Liaoning, where the reclamation areas were all more than 1000 km2. According to the remote sensing images, there are three coastal reclamation hotspot regions including Bohai bay (in which is located Liaoning, Tianjin and Hebei), Jiangsu province coastal area and Hangzhou bay (in Zhejiang province). A large scale land reclamation plan of more than 5880 km2 has been made by local government and 2469 km2 has approved by the State Council. From the analyzed results, there is a significant collinearity between these indicators, and no significant correlation between the area of reclamation and selected

Current temporal asymmetry and the role of tides: Nan-Wan Bay vs. the Gulf of Elat

Science.gov (United States)

Ashkenazy, Yosef; Fredj, Erick; Gildor, Hezi; Gong, Gwo-Ching; Lee, Hung-Jen

2016-05-01

Nan-Wan Bay in Taiwan and the Gulf of Elat in Israel are two different coastal environments, and as such, their currents are expected to have different statistical properties. While Nan-Wan Bay is shallow, has three open boundaries, and is directly connected to the open ocean, the Gulf of Elat is deep, semi-enclosed, and connected to the Red Sea via the Straits of Tiran. Surface currents have been continuously measured with fine temporal (less than or equal to 1 h) and spatial resolution (less than or equal to 1 km) for more than a year in both environments using coastal radars (CODARs) that cover a domain of roughly 10 × 10 km. These measurements show that the currents in Nan-Wan Bay are much stronger than those in the Gulf of Elat and that the mean current field in Nan-Wan Bay exhibits cyclonic circulation, which is stronger in the summer; in the Gulf of Elat, the mean current field is directed southward and is also stronger during the summer. We have compared the statistical properties of the current speeds in both environments and found that both exhibit large spatial and seasonal variations in the shape parameter of the Weibull distribution. However, we have found fundamental and significant differences when comparing the temporal asymmetry of the current speed (i.e., the ratio between the time during which the current speed increases and the total time). While the Nan-Wan Bay currents are significantly asymmetric, those of the Gulf of Elat are not. We then extracted the tidal component of the Nan-Wan Bay currents and found that it is strongly asymmetric, while the asymmetry of tidally filtered currents is much weaker. We thus conclude that the temporal asymmetry of the Nan-Wan Bay currents reported here is due to the strong tides in the region. We show that the asymmetry ratio in Nan-Wan Bay varies spatially and seasonally: (i) the currents increase rapidly and decay slowly in the northern part of the domain and vice versa in the southern part, and (ii) the

A Coastal Bay Summer Breeze Study, Part 2: High-resolution Numerical Simulation of Sea-breeze Local Influences

Science.gov (United States)

Calmet, Isabelle; Mestayer, Patrice G.; van Eijk, Alexander M. J.; Herlédant, Olivier

2018-04-01

We complete the analysis of the data obtained during the experimental campaign around the semi circular bay of Quiberon, France, during two weeks in June 2006 (see Part 1). A reanalysis of numerical simulations performed with the Advanced Regional Prediction System model is presented. Three nested computational domains with increasing horizontal resolution down to 100 m, and a vertical resolution of 10 m at the lowest level, are used to reproduce the local-scale variations of the breeze close to the water surface of the bay. The Weather Research and Forecasting mesoscale model is used to assimilate the meteorological data. Comparisons of the simulations with the experimental data obtained at three sites reveal a good agreement of the flow over the bay and around the Quiberon peninsula during the daytime periods of sea-breeze development and weakening. In conditions of offshore synoptic flow, the simulations demonstrate that the semi-circular shape of the bay induces a corresponding circular shape in the offshore zones of stagnant flow preceding the sea-breeze onset, which move further offshore thereafter. The higher-resolution simulations are successful in reproducing the small-scale impacts of the peninsula and local coasts (breeze deviations, wakes, flow divergences), and in demonstrating the complexity of the breeze fields close to the surface over the bay. Our reanalysis also provides guidance for numerical simulation strategies for analyzing the structure and evolution of the near-surface breeze over a semi-circular bay, and for forecasting important flow details for use in upcoming sailing competitions.

Interpretation FTIR spectrum of seawater and sediment in the Ambon Bay (TAD)

Science.gov (United States)

Patty, Diana Julaidy; Loupatty, Grace; Sopalauw, Fitria

2017-01-01

Research has done to interpretated FTIR spectrum of seawaters and sediment of the Ambon Bay (TAD). Analysis of samples of sediment and seawater using FTIR spectroscopy. The results showed the sand sediment samples identified Stretch bond OH group (3600-3500 cm-1), N-H Stretch (3400-3300 cm-1), C≡N (2250 cm-1), and NH bending (1640 to 1550 cm-1). And for seawater samples identified bonding group that is N-H Stretch (3400-3350 cm-1), N-H bending (1640 to 1550 cm-1) and C=O (1670-1640 cm-1). The existence of functional groups, carbonyl (C=O), alcohol (OH), carboxyl (COOH) can cause the complexation of metal cations. And the results showed analysis group N-O bond-containing compounds Nitro indicate heavy metal content of Lead (Pb) and group N-H bond-containing compound Amina indicate heavy metal content of Cadmium (Cd).

Nutrient fluxes and net metabolism in a coastal lagoon SW peninsula of Baja California, Mexico

Directory of Open Access Journals (Sweden)

Cervantes Duarte, R.

2016-09-01

Full Text Available Fluxes of nutrients and net metabolism were estimated in coastal lagoon Magdalena Bay using LOICZ biogeochemical model. In situ data were obtained from 14 sites in the lagoon and also from a fixed site in the adjacent ocean area. Intense upwelling (February to July and faint upwelling (August to January were analyzed from monthly time series. The Temperature, nitrite + nitrate, ammonium and phosphate within the lagoon showed significant differences (p<0.05 between the two periods. Salinity (p=0.408 was more homogeneous (no significantly different due to mixing processes. During the intense upwelling period, nutrients increased in and out of the lagoon due to the influence of Transitional Water and Subartic Water transported by the California Current. However, during the faint upwelling, from August to January, the Transition Water and Subtropical Surface Water were predominant. Magdalena Bay showed denitrification processes of throughout the year as it occurred in other semi-arid coastal lagoons. It also showed a net autotrophic metabolism during intense upwelling and heterotrophic metabolism during faint upwelling. Understanding nutrient flows and net metabolism through simple biogeochemical models can provide tools for better management of the coastal zone.

Flow and nutrient dynamics in a subterranean estuary (Waquoit Bay, MA, USA): Field data and reactive transport modeling

Science.gov (United States)

Spiteri, Claudette; Slomp, Caroline P.; Charette, Matthew A.; Tuncay, Kagan; Meile, Christof

2008-07-01

A two-dimensional (2D) reactive transport model is used to investigate the controls on nutrient ( NO3-, NH4+, PO 4) dynamics in a coastal aquifer. The model couples density-dependent flow to a reaction network which includes oxic degradation of organic matter, denitrification, iron oxide reduction, nitrification, Fe 2+ oxidation and sorption of PO 4 onto iron oxides. Porewater measurements from a well transect at Waquoit Bay, MA, USA indicate the presence of a reducing plume with high Fe 2+, NH4+, DOC (dissolved organic carbon) and PO 4 concentrations overlying a more oxidizing NO3--rich plume. These two plumes travel nearly conservatively until they start to overlap in the intertidal coastal sediments prior to discharge into the bay. In this zone, the aeration of the surface beach sediments drives nitrification and allows the precipitation of iron oxide, which leads to the removal of PO 4 through sorption. Model simulations suggest that removal of NO3- through denitrification is inhibited by the limited overlap between the two freshwater plumes, as well as by the refractory nature of terrestrial DOC. Submarine groundwater discharge is a significant source of NO3- to the bay.

Spatial distributions of and diurnal variations in low molecular weight carbonyl compounds in coastal seawater, and the controlling factors

Energy Technology Data Exchange (ETDEWEB)

Takeda, Kazuhiko, E-mail: takedaq@hiroshima-u.ac.jp [Graduate School of Biosphere Science, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8521 (Japan); Katoh, Shinya; Mitsui, Yumi; Nakano, Shinichi [Graduate School of Biosphere Science, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8521 (Japan); Nakatani, Nobutake [Graduate School of Biosphere Science, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8521 (Japan); Department of Environmental and Symbiotic Sciences, Rakuno Gakuen University, 582 Bunkyodai-Midorimachi, Ebetsu, Hokkaido 069-8501 (Japan); Sakugawa, Hiroshi [Graduate School of Biosphere Science, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8521 (Japan)

2014-09-15

We studied the spatial distributions of and the diurnal variations in four low molecular weight (LMW) carbonyl compounds, formaldehyde, acetaldehyde, propionaldehyde, and glyoxal, in coastal seawater. The samples were taken from the coastal areas of Hiroshima Bay, the Iyo Nada, and the Bungo Channel, western Japan. The formaldehyde, acetaldehyde, and glyoxal concentrations were higher in the northern part of Hiroshima Bay than at offshore sampling points in the Iyo Nada and the Bungo Channel. These three compounds were found at much higher concentrations in the surface water than in deeper water layers in Hiroshima Bay. It is noteworthy that propionaldehyde was not detected in any of the seawater samples, the concentrations present being lower than the detection limit (1 nanomole per liter (nM)) of the high performance liquid chromatography (HPLC) system we used. Photochemical and biological experiments were performed in the laboratory to help understand the characteristic distributions and fates of the LMW carbonyl compounds. The primary process controlling their fate in the coastal environment appears to be their biological consumption. The direct photo degradation of propionaldehyde, initiated by ultraviolet (UV) absorption, was observed, although formaldehyde and acetaldehyde were not degraded by UV irradiation. Our results suggest that the degradation of the LMW carbonyl compounds by photochemically formed hydroxyl radicals is relatively insignificant in the study area. Atmospheric deposition is a possible source of soluble carbonyl compounds in coastal surface seawater, but it may not influence the carbonyl concentrations in offshore waters. - Highlights: • Low molecular weight (LMW) carbonyl compounds in coastal seawater were determined. • Photochemical productions of LMW carbonyl compounds in seawater were observed. • LMW carbonyl compounds were largely consumed biologically. • Photochemical degradation was relatively insignificant in the study area.

Spatial distributions of and diurnal variations in low molecular weight carbonyl compounds in coastal seawater, and the controlling factors

International Nuclear Information System (INIS)

Takeda, Kazuhiko; Katoh, Shinya; Mitsui, Yumi; Nakano, Shinichi; Nakatani, Nobutake; Sakugawa, Hiroshi

2014-01-01

We studied the spatial distributions of and the diurnal variations in four low molecular weight (LMW) carbonyl compounds, formaldehyde, acetaldehyde, propionaldehyde, and glyoxal, in coastal seawater. The samples were taken from the coastal areas of Hiroshima Bay, the Iyo Nada, and the Bungo Channel, western Japan. The formaldehyde, acetaldehyde, and glyoxal concentrations were higher in the northern part of Hiroshima Bay than at offshore sampling points in the Iyo Nada and the Bungo Channel. These three compounds were found at much higher concentrations in the surface water than in deeper water layers in Hiroshima Bay. It is noteworthy that propionaldehyde was not detected in any of the seawater samples, the concentrations present being lower than the detection limit (1 nanomole per liter (nM)) of the high performance liquid chromatography (HPLC) system we used. Photochemical and biological experiments were performed in the laboratory to help understand the characteristic distributions and fates of the LMW carbonyl compounds. The primary process controlling their fate in the coastal environment appears to be their biological consumption. The direct photo degradation of propionaldehyde, initiated by ultraviolet (UV) absorption, was observed, although formaldehyde and acetaldehyde were not degraded by UV irradiation. Our results suggest that the degradation of the LMW carbonyl compounds by photochemically formed hydroxyl radicals is relatively insignificant in the study area. Atmospheric deposition is a possible source of soluble carbonyl compounds in coastal surface seawater, but it may not influence the carbonyl concentrations in offshore waters. - Highlights: • Low molecular weight (LMW) carbonyl compounds in coastal seawater were determined. • Photochemical productions of LMW carbonyl compounds in seawater were observed. • LMW carbonyl compounds were largely consumed biologically. • Photochemical degradation was relatively insignificant in the study area

Using Bayesian Network as a tool for coastal storm flood impact prediction at Varna Bay (Bulgaria, Western Black Sea)

Science.gov (United States)

Valchev, Nikolay; Eftimova, Petya; Andreeva, Nataliya; Prodanov, Bogdan

2017-04-01

Coastal zone is among the fastest evolving areas worldwide. Ever increasing population inhabiting coastal settlements develops often conflicting economic and societal activities. The existing imbalance between the expansion of these activities, on one hand, and the potential to accommodate them in a sustainable manner, on the other, becomes a critical problem. Concurrently, coasts are affected by various hydro-meteorological phenomena such as storm surges, heavy seas, strong winds and flash floods, which intensities and occurrence frequency is likely to increase due to the climate change. This implies elaboration of tools capable of quick prediction of impact of those phenomena on the coast and providing solutions in terms of disaster risk reduction measures. One such tool is Bayesian network. Proposed paper describes the set-up of such network for Varna Bay (Bulgaria, Western Black Sea). It relates near-shore storm conditions to their onshore flood potential and ultimately to relevant impact as relative damage on coastal and manmade environment. Methodology for set-up and training of the Bayesian network was developed within RISC-KIT project (Resilience-Increasing Strategies for Coasts - toolKIT). Proposed BN reflects the interaction between boundary conditions, receptors, hazard, and consequences. Storm boundary conditions - maximum significant wave height and peak surge level, were determined on the basis of their historical and projected occurrence. The only hazard considered in this study is flooding characterized by maximum inundation depth. BN was trained with synthetic events created by combining estimated boundary conditions. Flood impact was modeled with the process-based morphodynamical model XBeach. Restaurants, sport and leisure facilities, administrative buildings, and car parks were introduced in the network as receptors. Consequences (impact) are estimated in terms of relative damage caused by given inundation depth. National depth

Limit loads for pipe bends under combined pressure and in-plane bending based on finite element limit analysis

International Nuclear Information System (INIS)

Oh, Chang Sik; Kim, Yun Jae

2006-01-01

In the present paper, approximate plastic limit load solutions for pipe bends under combined internal pressure and bending are obtained from detailed three-dimensional (3-D) FE limit analyses based on elastic-perfectly plastic materials with the small geometry change option. The present FE results show that existing limit load solutions for pipe bends are lower bounds but can be very different from the present FE results in some cases, particularly for bending. Accordingly closed-form approximations are proposed for pipe bends under combined pressure and in-plane bending based on the present FE results. The proposed limit load solutions would be a basis of defective pipe bends and be useful to estimate non-linear fracture mechanics parameters based on the reference stress approach

Radon concentration and its relation with some environmental conditions in the northern safaga bay

International Nuclear Information System (INIS)

Al-Arabi, A.M.; Tartor, B.A.; Bashter, I.I.; El-Saman, M.I.; Maiyza, I.A.

2005-01-01

The coastal zone along the Red Sea at Safaga town is a site for industrial development and accepting future establishment of dense recreational resorts. It includes Safaga harbour in which international trade depends. Until now most of the coastal area at Safaga is pristine and suffering from continuous increasing population densities. There is no idea about the distribution of hydro graphic parameters or radon level in the northern Safaga bay in spite of the area famous as the treatment area for Psoriases and Rheumatoid as will as attractive area for tourism. The relative high relations exist between the radioactivity component and the ph, specific conductivity, water salinity, water density and dissolved oxygen were calculated. The concentration of 226 R a, 232 T h and 40 K in sediment samples collected from bottom of the northern Safaga Bay fluctuated between 5 to 19 Bq.kg-1, 4 to 19 Bq.kg-1 and 1545 to 6122 Bq.kg-1, respectively. Whereas the concentration of radon air varies between 2 -11 Bq.cm-3

Social-Ecological System in Seagrass Ecosystem Management at Kotania Bay Waters, Western Seram, Indonesia

Science.gov (United States)

Wawo, Mintje

2017-10-01

The concept of the Social-Ecological System (SES) of the coastal region, can be found in the seagrass ecosystem in the Kotania Bay Waters. Seagrass ecosystem as one of the productive ecosystem is part of an ecological system that can influence and influenced social system, in this case by people living around the seagrass ecosystem. This aim to estimating the socio-ecological vulnerability system of the seagrass ecosystem in the Kotania Bay Waters, the Linkage Matrix is used (de Chazal et al., 2008). This linkage matrix was created to determine the perception and understanding of the community on the ecosystem services provided by the seagrass ecosystem through the appraisal of various stakeholders. The results show that social values are rooted in the public perception of ecosystem goods and services, which are rarely considered. The ecological and economic value of natural resources is increasingly being used to determine the priority areas in the planning and management of coastal areas. The social value that exists in natural resources is highly recognized in conservation.

Trends in Accretion Rates of Riverine Sediments in a Distal Bay and Wetlands Using 7-Beryllium as a Tracer: Fourleague Bay, Louisiana.

Science.gov (United States)

Restreppo, G. A.; Bentley, S. J.; Wang, J.; Xu, K.

2017-12-01

To combat land loss along the Mississippi River Delta, Louisiana has launched a historic campaign to sustain and regrow coastal lands using, in part, sediment diversions. Previous research has focused primarily on sand sized sediment load, which is usually deposited proximal to a river's delta or a diversion's outlet. Fine sediments constitute the majority of sediment load in the Mississippi, but are under-studied with respect to dispersal processes, particularly in terms of sediment supply to distal deltaic bays and wetlands. The Atchafalaya River and associated wetlands serve as prime study areas for this purpose. Bimonthly time-series push cores were collected from May 2015 to May 2016 along ten sites within Fourleague Bay, Louisiana. Fourleague Bay has remained stable against the deteriorative effects of relative sea level rise, standing out along Louisiana's declining coastline. Of the ten field sites, five are located across a longitudinal transect in the middle bay, while the other five are located in adjacent marshes. All sites fall within 10 to 30 km of the Atchafalaya Delta, extending south towards the Gulf of Mexico. Cores were extruded in 2 cm intervals, dried, ground, and analyzed via gamma spectrometry for the presence of 7Be. Inventories of 7Be were then calculated and used to determine daily mass accretion rate (MAR) over twelve months. Average MAR values for the bay and the marshes are compared with Atchafalaya River discharge, wind data, and atmospheric pressure through the year of sampling. Peak marsh MAR, 0.88 ± 0.20 kg m-2 d-1, occurs just after historically high river discharge. Peak bay MAR, 1.2 ± 0.67 kg m-2 d-1, occurs during seasonal low river discharge and calm winds. Average bay and marsh MARs have a moderate to strong, negative correlation when compared. Results indicate sediment bypass of the bay floor during periods of moderate to high river discharge, entering the marshes directly when inundation occurs and enhanced by the passage

Comparative study of isotopic trends in two coastal ecosystems of North Biscay: A multitrophic spatial gradient approach

Science.gov (United States)

Mortillaro, J. M.; Schaal, G.; Grall, J.; Nerot, C.; Brind'Amour, A.; Marchais, V.; Perdriau, M.; Le Bris, H.

2014-01-01

In coastal estuarine embayments, retention of water masses due to coastal topography may result in an increased contribution of continental organic matter in food webs. However, in megatidal embayments, the effect of topography can be counterbalanced by the process of tidal mixing. Large amounts of continental organic matter are exported each year by rivers to the oceans. The fate of terrestrial organic matter in food webs of coastal areas and on neighboring coastal benthic communities was therefore evaluated, at multi-trophic levels, from primary producers to primary consumers and predators. Two coastal areas of the French Atlantic coast, differing in the contributions from their watershed, tidal range and aperture degree, were compared using carbon and nitrogen stable isotopes (δ13C and δ15N) during two contrasted periods. The Bay of Vilaine receives large inputs of freshwater from the Vilaine River, displaying 15N enriched and 13C depleted benthic communities, emphasizing the important role played by allochtonous inputs and anthropogenic impact on terrestrial organic matter in the food web. In contrast, the Bay of Brest which is largely affected by tidal mixing, showed a lack of agreement between isotopic gradients displayed by suspended particulate organic matter (SPOM) and suspension-feeders. Discrepancy between SPOM and suspension-feeders is not surprising due to differences in isotopes integration times. We suggest further that such a discrepancy may result from water replenishment due to coastal inputs, nutrient depletion by phytoplankton production, as well as efficient selection of highly nutritive phytoplanktonic particles by primary consumers.

Distribution and spectral characteristics of chromophoric dissolved organic matter in a coastal bay in northern China.

Science.gov (United States)

Li, Guiju; Liu, Jing; Ma, Yulan; Zhao, Ruihua; Hu, Suzheng; Li, Yijie; Wei, Hao; Xie, Huixiang

2014-08-01

The absorption spectra of chromophoric dissolved organic matter (CDOM), along with general physical, chemical and biological variables, were determined in the Bohai Bay, China, in the springs of 2011 and 2012. The absorption coefficient of CDOM at 350 nm (a350) in surface water ranged from 1.00 to 1.83 m⁻¹ (mean: 1.35 m⁻¹) in May 2011 and from 0.78 to 1.92 m⁻¹ (mean: 1.19 m⁻¹) in April 2012. Little surface-bottom difference was observed due to strong vertical mixing. The a350 was weakly anti-correlated to salinity but positively correlated to chlorophyll a (Chl-a) concentration. A shoulder over 260-290 nm, suggestive of biogenic molecules, superimposed the overall pattern of exponentially decreasing CDOM absorption with wavelength. The wavelength distribution of the absorption spectral slope manifested a pronounced peak at ca. 300 nm characteristic of algal-derived CDOM. All a250/a365 ratios exceeded 6, corresponding to CDOM molecular weights (Mw) of less than 1 kDa. Spectroscopically, CDOM in the Bohai Bay differed substantively from that in the Haihe River, the bay's dominant source of land runoff; photobleaching of the riverine CDOM enlarged the difference. Results point to marine biological production being the principal source of CDOM in the Bohai Bay during the sampling seasons. Relatively low runoff, fast dilution, and selective photodegradation are postulated to be among the overarching elements responsible for the lack of terrigenous CDOM signature in the bay water. Copyright © 2014. Published by Elsevier B.V.

Semi-Permeable Paleochannels as Conduits for Submarine Groundwater Discharge to the Coast in Barataria Bay, Louisiana

Science.gov (United States)

Breaux, A.; Kolker, A.; Telfeyan, K.; Kim, J.; Johannesson, K. H.; Cable, J. E.

2014-12-01

Many studies have focused on hydrological and geochemical fluxes to the ocean from land to the ocean via submarine groundwater discharge (SGD), however few have assessed these contributions of SGD in deltaic settings. The Mississippi River delta is the largest delta in North America, and the magnitude of groundwater that discharges from the river into its delta is relatively unknown. Hydrological budgets indicate that there is a large magnitude of surface water lost in the Mississippi's delta as the river flows into the Gulf of Mexico. Recent evidence in our study indicates that paleochannels, or semi-permeable buried sandy bodies that were former distributaries of the river, allow for water to discharge out of the Mississippi's main channel and into its delta driven by a difference in hydraulic head between the river and the lower lying coastal embayments. Our study uses geophysical data, including sonar and resistivity methods, to detect the location of these paleochannels in Barataria Bay, a coastal bay located in the Mississippi Delta. High resolution CHIRP sonar data shows that these paleochannel features are ubiquitous in the Mississippi Delta, whereas resistivity data indicates that lower salinity water is found during high river flow in bays proximate to the river. Sediment core analysis is also used to characterize the area of study, as well as further understand the regional geology of the Mississippi Delta and estimate values of permeability and hydraulic conductivity of sediments taken from two locations in Barataria Bay. The geophysical and sediment core data will likewise be used to contextualize geochemical data collected in the field, which includes an assessment of major cations and anions, as well as in situ Rn-222 activities, a method that has been proven to be useful as a tracer of groundwater movement. The results may be useful in understanding the potential global magnitude of hydrological and geochemical fluxes of other large rivers with

Behaviour of Radium in coastal marine water of India - Behaviour of Radium in coastal marine environment of India

Energy Technology Data Exchange (ETDEWEB)

Jha, S.K.; Sartandel, S.; Tripathi, R.M. [Environmental Radioactivity measurement Section, Health Physics Division, Bhabha Atomic Research Centre, Mumbai-400085 (India)

2014-07-01

In the recent years, there has also been an increased recognition of the radiological significance of non-nuclear process of natural radioactivity in particular {sup 226}Ra, {sup 228}Ra, {sup 222}Rn, {sup 210}Po and {sup 210}Pb produced, for example by Phosphate processing plants, offshore oil and gas installations and ceramic industries etc. Keeping this in mind, special distribution of radium was carried out to generate region specific values of Radium. The Indian Ocean differs from the Atlantic and Pacific Oceans in its limited northward extent, to only 25 deg. N. Indian subcontinent divides the Indian ocean in the north into two tropical basin namely Arabian sea and Bay of Bengal both being located within same latitude and being under the direct influence of monsoon. For measurements of {sup 226}Ra and {sup 228}Ra concentration in the coastal marine waters of India, MnO{sub 2} impregnated cartridge based in-situ pre-concentration technique was applied by passing 1000 liters of seawater at thirty locations covering Arabian Sea in the west of India and Bay of Bengal in the east. {sup 226}Ra was estimated using gamma ray peak of its daughter radionuclides {sup 214}Bi and {sup 214}Pb while {sup 228}Ra was estimated from its daughter {sup 228}Ac. {sup 214}Pb emissions occur at 295 and 352 keV; {sup 214}Bi has an emission at 609 keV. For {sup 228}Ac gamma emissions at 911 keV, 968 keV and 338 keV were used. In the coastal waters, {sup 226}Ra and {sup 228}Ra concentration was observed to be in the range of 0.69 to 4.10 mBql{sup -1} and 0.70 to 8 Bq m{sup -3} respectively with an average of 1.52 and 4.53 Bq m{sup -3}. The concentration of {sup 228}Ra was observed to be more than {sup 226}Ra in all the locations. The activity ratio of {sup 228}Ra/{sup 226}Ra in coastal marine water from the Bay of Bengal showed a ratio varying from 0.8 to 2.4 with a mean of 2.1.In the present study, activity ratio varies from 1.9 to 2.4 at Karaikkal. But the regions of Rameswaram and

Temporal and spatial patterns in ichthyoplankton assemblages in bay and open coastal environments.

Science.gov (United States)

Kent, J; Jenkins, G; Acevedo, S

2013-02-01

The larval fish fauna occurring in temperate bay and shelf waters off Victoria, southern Australia, was found to be diverse, comprising taxa from 52 families. The most abundant groups collected were gobiids, tripterygiids, gobiesocids and clupeids. Fish egg concentrations were highest during spring and summer (September to February). Eggs of the Australian anchovy Engraulis australis occurred mainly during spring (September to November). Total larval fish concentrations were highest during summer (December to February), and were significantly higher at 1 km than 2 and 5 km from shore in offshore samples. Larval concentrations of a number of families, mainly reef-associated taxa that attach their eggs to hard substrata, were also higher nearer to shore. These larvae are more developed upon hatching than those of pelagic spawners and more capable of avoiding passive drift. Multivariate analyses found that larval taxonomic composition did not vary significantly with distance from shore, but that seasonal and monthly groupings were evident, with different taxa dominating at different times of the year. Larvae of the families Gobiidae and Tripterygiidae occurred in all months, but were less abundant during winter. Spatial differences in the larval fish assemblage between offshore samples and samples taken in the bay were only apparent during summer. This was primarily due to a higher abundance of seagrass-associated species, such as syngnathids and hemiramphids, utilizing specific habitats in the bay. © 2013 The Authors. Journal of Fish Biology © 2013 The Fisheries Society of the British Isles.

137Cs and 210Pb distribution in Manila Bay sediment

International Nuclear Information System (INIS)

Sta. Maria, Efren J.; Madrid, Jordan F.; Olivares, Ryan U.; Bulos, Adelina DM; Dayaon, Jennyvi P.; Asa, Anie Day DC; Sombrito, Elvira Z.

2011-01-01

Two radionuclides were measured in surface sediment samples taken from geographically distributed sections of Manila Bay, namely cesium-137 ( 137 Cs) and lead-210 ( 210 Pb). Results indicated a noticeable change in the radioactivity concentration levels in sediments collected in 2005 and 2010, with a median concentration of 1.0 and 2.64 Bq kg -1 , respectively. Higher levels of 137 Cs radioactivity were measured in the northern and inner portion of the bay adjacent to major river systems, agricultural and highly industrialized urban areas. 137 Cs isotope increased in activity in most of the samples especially in the northwestern areas of Bataan and Pampanga with five times more than the activity from the first sampling measurements. Nevertheless, radioactivity concentrations observed in surface sediments along the bay are within the range of radioactivity in several areas monitored in the Northern Hemisphere. The country has been frequented by tropical cyclones and storms that have caused erosion, which may have introduced elevated material input in the bay. In addition, wind-driven circulation especially in the shallower areas of the bay is a possibility for the substantial sediment movement and accumulation along this coast. Conversely, areas with higher 137 Cs have lower values of 210 Pb. In an undisturbed environment, 210 Pb deposition values are assumed nearly constant. Hence, changes in the radioactivity concentration levels of these radionuclides can be an indicator of pollution input from land-based sources, sediment movement and reworking in the coastal areas. At present, there is very limited information on the radioactivity level of various radioisotopes in Manila Bay.The data obtained are benchmark values against which changes that will be occurring in the bay can be assessed. (author)

Preparing to predict: The Second Autonomous Ocean Sampling Network (AOSN-II) experiment in the Monterey Bay

Science.gov (United States)

Ramp, S. R.; Davis, R. E.; Leonard, N. E.; Shulman, I.; Chao, Y.; Robinson, A. R.; Marsden, J.; Lermusiaux, P. F. J.; Fratantoni, D. M.; Paduan, J. D.; Chavez, F. P.; Bahr, F. L.; Liang, S.; Leslie, W.; Li, Z.

2009-02-01

The Autonomous Ocean Sampling Network Phase Two (AOSN-II) experiment was conducted in and offshore from the Monterey Bay on the central California coast during July 23-September 6, 2003. The objective of the experiment was to learn how to apply new tools, technologies, and analysis techniques to adaptively sample the coastal ocean in a manner demonstrably superior to traditional methodologies, and to use the information gathered to improve predictive skill for quantities of interest to end-users. The scientific goal was to study the upwelling/relaxation cycle near an open coastal bay in an eastern boundary current region, particularly as it developed and spread from a coastal headland. The suite of observational tools used included a low-flying aircraft, a fleet of underwater gliders, including several under adaptive autonomous control, and propeller-driven AUVs in addition to moorings, ships, and other more traditional hardware. The data were delivered in real time and assimilated into the Harvard Ocean Prediction System (HOPS), the Navy Coastal Ocean Model (NCOM), and the Jet Propulsion Laboratory implementation of the Regional Ocean Modeling System (JPL/ROMS). Two upwelling events and one relaxation event were sampled during the experiment. The upwelling in both cases began when a pool of cold water less than 13 °C appeared near Cape Año Nuevo and subsequently spread offshore and southward across the bay as the equatorward wind stress continued. The primary difference between the events was that the first event spread offshore and southward, while the second event spread only southward and not offshore. The difference is attributed to the position and strength of meanders and eddies of the California Current System offshore, which blocked or steered the cold upwelled water. The space and time scales of the mesoscale variability were much shorter than have been previously observed in deep-water eddies offshore. Additional process studies are needed to elucidate

Paleoseismic and Paleogeographic Reconstruction of the Central Coastal of Ecuador: Insights from Quaternary Geological Data for the Jaramijó bay area

Science.gov (United States)

Chunga, K.; Maurizio, M.; Garces, D.; Quiñonez, M. F.; Peña, G. E.

2015-12-01

Late Holocene sequences of loose to weakly consolidated sand and clay sediments intercalated with volcanic-ash layers (particles transported by fall-out), are outcrops on a sea cliff in the Jaramijó bay area (situated 7 km away in the East direction from Manta city, Manabí, at the middle section of Ecuador's Pacific coastline). The main geomorphologic feature in the site is the wave-cut beach platform permanently exposed at the lowest tides and an 18 m-high coastal cliff retreat with an estimated rate of ca. 2.5 meter/year (Chunga, 2014). One of the most remarkable geoarchaeological evidences found in this outcrop, it is the remains of two large bones (ie., radius and radial) of the human forearm of ca. 800 years ago (with archaeological vestiges of the Manteña culture) covered by a 8 to 25 cm-thick volcanic ash layer, stratigraphically at the top, an erosive contact with chaotic deposition of medium to fine-grained sand which indicates a potential tsunami deposit. Moreover, several volcanic ash and lahar layers are well distinguished on the sea cliff, which are associated with pyroclastic products transported as lahars from the Quilotoa and Cotopaxi, Pululahua volcanic structures (northern Andes in Ecuador) situated at a distance between of 150-190 kilometers (Mothes and Hall, 2008; Usselman, 2006). It is not excluded that previous pre-Columbian cultures also have been displaced in the last 2,000 years by disastrous geological events such as subduction earthquakes, local tsunami and volcanic lahar-ash deposits. All of these stratigraphic and palaeoseismologic features will allow us to understand the catastrophic geological events that abruptly shaped the landscape, furthermore, to investigate the changes of moderate to high Late Holocene progradation rates of the Jaramijó bay coastline.

Geomicrobiology of cores from Suruí Mangrove--Guanabara Bay--Brazil.

Science.gov (United States)

Fontana, Luiz Francisco; Mendonça Filho, João Graciano; Netto, Annibal Duarte Pereira; Sabadini-Santos, Elisamara; de Figueiredo, Alberto Garcia; Crapez, Mirian Araújo Carlos

2010-10-01

The aim of this work was to quantify the biopolymers associated to esterase enzymes and identify bacterial respiratory activity in four cores collected in Suruí Mangrove, Guanabara Bay - RJ. Biopolymer concentration was 1000 times lower than previously reported in the literature, indicating the need for creating and establishing eutrophication indicative rates and records compatible with tropical coastal systems. The biochemical representative relationships in the cores were equivalent to those from studies on coastal marine environments made in the Northern Hemisphere. The esterase enzymes in the sediment proved efficient in the mineralization of biopolymers, even with preferentially anaerobic metabolic physiology. Despite the lack of incipient geomicrobiological studies, the results highlighted the possible application of microbiology to a better understanding of geological processes. Copyright © 2010 Elsevier Ltd. All rights reserved.

Nutrient sequestration in Aquitaine lakes (SW France) limits nutrient flux to the coastal zone

Science.gov (United States)

Buquet, Damien; Anschutz, Pierre; Charbonnier, Céline; Rapin, Anne; Sinays, Rémy; Canredon, Axel; Bujan, Stéphane; Poirier, Dominique

2017-12-01

Oligotrophic coastal zones are disappearing from increased nutrient loading. The quantity of nutrients reaching the coast is determined not only by their original source (e.g. fertilizers used in agriculture, waste water discharges) and the land use, but also by the pathways through which nutrients are cycled from the source to the river mouth. In particular, lakes sequester nutrients and, hence, reduce downstream transfer of nutrients to coastal environments. Here, we quantify the impact of Aquitaine great lakes on the fluxes of dissolved macro-nutrients (N, P, Si) to the Bay of Biscay. For that, we have measured nutrient concentrations and fluxes in 2014 upstream and downstream lakes of Lacanau and Carcans-Hourtin, which belongs to the catchment of the Arcachon Bay, which is the largest coastal lagoon of the Bay of Biscay French coast. Data were compared to values obtained from the Leyre river, the main freshwater and nutrient source for the lagoon. Results show that processes in lakes greatly limit nutrient flux to the lagoon compared to fluxes from Leyre river, although the watershed is similar in terms of land cover. In lakes, phosphorus and silicon are trapped for long term in the sediment, silicon as amorphous biogenic silica and phosphorus as organic P and P associated with Fe-oxides. Nitrogen that enters lakes mostly as nitrate is used for primary production. N is mineralized in the sediment; a fraction diffuses as ammonium. N2 production through benthic denitrification extracts only 10% of dissolved inorganic nitrogen from the aquatic system. The main part is sequestered in organic-rich sediment that accumulates below 5 m depth in both lakes.

Downward Migration of Coastal Conifers as a Response to Recent Land Emergence in Eastern Hudson Bay, Québec

Science.gov (United States)

Bégin, Yves; Bérubé, Dominique; Grégoire, Martin

1993-07-01

Postglacial uplift in the eastern Hudson Bay area is among the most rapid in the world (300 m during the last 8000 yr). Although emergence curves based on 14 C-dated raised shorelines give a consistent basis for modeling relative sea-level changes, such a low-resolution dating method is inappropriate for estimating trends over recent decades. A major downward displacement of white spruce ( Picea glauca (Moench) Voss) and tamarack ( Larix laricina (DuRoi) K. Koch) occurred on protected shores as a response to shoreline retreat during this century. Analysis of the age distribution of trees indicates a progradation of white spruce and tamarack on gently sloping terrain ranging from 1.3 and 2.6 cm/yr, respectively, toward the sea. Improvement of climatic conditions during the 20th century favored such expansion which was probably faster than the real land emergence rates, but recent episodes of high water levels caused regression of forest margins over the highly exposed shores. Nevertheless, the downward trend of the treeline over this century substantiates the projections of 14C-dated coastal emergence curves during the modern period (1.0 to 1.3 cm/yr) by providing an estimate of the maximum rates of shoreline retreat.

Population structure and maturity stages of Fritillaria borealis (Appendicularia, Tunicata: seasonal cycle in Ushuaia Bay (Beagle Channel

Directory of Open Access Journals (Sweden)

María Laura Presta

2015-09-01

Full Text Available AbstractFritillaria borealis is a cosmopolitan species, very frequent in sub-antarctic and antarctic waters. The objective of this paper was to analyze its size structure and maturity stages at two sites in Ushuaia Bay: a coastal site exposed to anthropogenic pressure (E1 and a reference site (E2 located in the external zone of the bay. Zooplankton was collected during the 2012 seasonal cycle. The sampling method involved the use of a 67 µm-mesh net. Appendicularians were classified in four maturity stages: I undifferentiated gonads, II testis and ovary differentiated, III expanded testis, IV discharged testis, expanded ovary. Our results showed that the highest densities of F. borealisoccurred in spring and summer at both sites; coinciding with high values of chlorophyll-a. The percentage of juveniles (I and II exhibited a spatial and temporal pattern similar to that observed for chlorophyll-a values. During spring-summer, juveniles and mature specimens (III and IV showed a greater gonadal development than those individuals found in autumn-winter. In conclusion, the mismatching in the population structure and the pattern of densities of F. borealis between coastal and external zones would suggest the existence of two sub-populations susceptible to the influence of the anthropogenic impact in the bay.

Studies applications through tracers techniques and effluent contaminants dispersing in Montevideo coastal waters and east beaches

International Nuclear Information System (INIS)

Suarez, R.; Dellepere, A.; Pintos, A.; Barreiro, M.; Odino, R.; Souto, B.; Badano, A.; Crosignani, L.; Moreno, S.

1995-01-01

With the purpose to define or not the contamination influence in Montevideo coastal waters, uranine and tritium tracers were injected in outlet river. A higher grade of contamination was found in the Montevideo Bay, and several recommendations were given for the future

Tampa Bay 1/3 arc-second NAVD 88 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. These integrated...

Rupture prediction for induction bends under opening mode bending with emphasis on strain localization

International Nuclear Information System (INIS)

Mitsuya, Masaki; Sakanoue, Takashi

2015-01-01

This study focuses on the opening mode of induction bends; this mode represents the deformation outside a bend. Bending experiments on induction bends are shown and the manner of failure of these bends was investigated. Ruptures occur at the intrados of the bends, which undergo tensile stress, and accompany the local reduction of wall thickness, i.e., necking that indicates strain localization. By implementing finite element analysis (FEA), it was shown that the rupture is dominated not by the fracture criterion of material but by the initiation of strain localization that is a deformation characteristic of the material. These ruptures are due to the rapid increase of local strain after the initiation of strain localization and suddenly reach the fracture criterion. For the evaluation of the deformability of the bends, a method based on FEA that can predict the displacement at the rupture is proposed. We show that the yield surface shape and the true stress–strain relationship after uniform elongation have to be defined on the basis of the actual properties of the bend material. The von Mises yield criterion, which is commonly used in cases of elastic–plastic FEA, could not predict the rupture and overestimated the deformability. In contrast, a yield surface obtained by performing tensile tests on a biaxial specimen could predict the rupture. The prediction of the rupture was accomplished by an inverse calibration method that determined the true stress-strain relationship after uniform elongation. As an alternative to the inverse calibration, a simple extrapolation method of the true stress-strain relationship after uniform elongation which can predict the rupture is proposed. - Highlights: • A method based on FEA that can predict the displacement at the rupture is proposed. • The yield surface shape and the true stress–strain have to be defined precisely. • The von Mises yield criterion overestimated the deformability. • The ruptures are due to the

Process-based, morphodynamic hindcast of decadal deposition (1856-1887) and erosion (1951-1983) patterns in San Pablo Bay, California

Science.gov (United States)

Wegen, M. V.; Jaffe, B. E.; Roelvink, J.

2009-12-01

obtained in sub-areas of San Pablo Bay. Modeling the erosional period is more sensitive to bed composition data and leads to worse results. This is partly attributed to the fact that morphodynamic change was much smaller than during the depositional period. The research is part of larger project, CASCaDE (http://cascade.wr.usgs.gov/). CASCaDE is supported by the U.S Geological Survey’s Priority Ecosystems Science program and the CALFED Bay/Delta Program. Cappiella, K., Malzone, C. , Smith R., Jaffe, B.E., 1999. Sedimentation and bathymetric change in Suisun Bay 1876-1990. USGS Open File Report, 9-563. Ganju, N.K., Knowles, N., and Schoellhamer, D.H., in 2008, Temporal downscaling of decadal sediment load estimates to a daily interval for use in hindcast simulations. Journal of Hydrology, v. 349, p. 512-523. Jaffe, B.E., Smith R.E. and Foxgrover A.C., 2007. Anthropogenic influence on sedimentation and intertidal mudflat change in San Pablo Bay, California: 1856-1983. Estuarine, Coastal and Shelf Science 73 175-187. Roelvink, J. A. (2006), Coastal morphodynamic evolution techniques, J. Coastal Eng., 53, 177-187.

Feasibility of green mussel, Perna viridis farming in Marudu Bay, Malaysia

Directory of Open Access Journals (Sweden)

Tan Kar Soon

2016-11-01

Full Text Available Bivalve aquaculture is an important source of affordable animal protein for coastal community. The success and sustainability of this industry is highly influenced by the suitability of the environment in which it is carried out. Present study was carried out to evaluate the feasibility of green mussel (Perna viridis farming in Marudu Bay. The site suitability for green mussel farming was evaluated based on biophysical parameters and food availability. The in situ environmental parameters, phytoplankton abundance and composition were collected from 10 sampling stations on monthly interval from May 2014 to April 2015. The results showed that the environmental parameters and food availability in most of the sampling stations were suitable for green mussel. However, the presence of phytoplankton taxa (Chaetoceraceae which are unfavorable by green mussel in most of the stations located at the bay pocket make those areas less recommended for green mussel farming. In contrast, stations located on the mouth of the bay exhibited high site suitability rating points and hence are highly recommended for cultivation of green mussel.

Bend me, shape me

CERN Multimedia

2002-01-01

A Japanese team has found a way to bend and shape silicon substrates by growing a thin layer of diamond on top. The technique has been proposed as an alternative to mechanical bending, which is currently used to make reflective lenses for X-ray systems and particle physics systems (2 paragraphs).

Dissolved Platinum Concentrations in Coastal Seawater: Boso to Sanriku Areas, Japan.

Science.gov (United States)

Mashio, Asami Suzuki; Obata, Hajime; Gamo, Toshitaka

2017-08-01

Platinum, one of the rarest elements in the earth's crust, is now widely used in a range of products, such as catalytic converters in automobiles and anticancer drugs. Increasing use and dispersal of platinum has the potential to affect aquatic environments. Platinum concentrations in open ocean seawater have been found to be very low (approximately 0.2 pmol/L); however, Pt distributions and biogeochemical cycles in coastal areas are unknown. In this study, we investigated Pt concentrations in coastal waters between the Boso and Sanriku areas, Japan, after the 2011 tsunami. We determined sub-picomolar levels of dissolved Pt using isotope-dilution Inductively coupled plasma mass spectrometry after column preconcentration with an anion exchange resin. Dissolved Pt concentrations were found to be in the range 0.20-1.5 pmol/L, with the highest concentration in bottom water of the Boso coastal area, and at stations close to Tokyo Bay. Assuming thermodynamical equilibrium, Pt was determined to be present in the form PtCl 5 (OH) 2- , even in low-oxygen coastal waters. Vertical profiles indicated Pt levels increased toward seafloors near coastal stations and were similar to those of the open ocean at trench stations. High concentrations of dissolved Pt are thought to be derived from coastal sediments.

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

Partial pressure (or fugacity) of carbon dioxide, 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 NOAA Ship GORDON GUNTER in the Bay of Fundy, Coastal Waters of Florida and others from 2015-03-03 to 2015-10-25 (NCEI Accession 0157408)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0157408 includes Surface underway, chemical, meteorological and physical data collected from NOAA Ship GORDON GUNTER in the Bay of Fundy, Coastal...

On the accuracy of analyses for in-plane bending of smooth pipe bends with end constraints

International Nuclear Information System (INIS)

Thomson, G.; Spence, J.

1985-01-01

The accuracy of theoretical analyses for in-plane bending of smooth pipebends with end constraints is discussed and investigated with a view to explaining and reducing the differences between the major works. An earlier theory of the authors is improved to give more accurate answers for bends with rigid flanges. Flanged bends are then examined in some detail, quantifying for the first time the important influence of the flange rigidity on the bend flexibility and stresses. A summary of some finite element analyses is presented from which it is clear that further work is desirable. (orig.)

North Inlet • Winyah Bay (NIW) National Estuarine Research Reserve Meteorological Data, North Inlet Estuary, Georgetown, South Carolina: 1997 • 1999.

Data.gov (United States)

Baruch Institute for Marine and Coastal Sciences, Univ of South Carolina — The North Inlet Estuary and the adjacent lower northeastern section of Winyah Bay Estuary were designated as part of the National Estuarine Research Reserve System...

Effect of bend separation distance on the mass transfer in back-to-back pipe bends arranged in a 180° configuration

Science.gov (United States)

Chen, X.; Le, T.; Ewing, D.; Ching, C. Y.

2016-12-01

The mass transfer to turbulent flow through back-to-back pipe bends arranged in a 180° configuration with different lengths of pipe between the bends was measured using a dissolving gypsum test section in water. The measurements were performed for bends with a radius of curvature of 1.5 times the pipe diameter ( D) at a Reynolds numbers of 70,000 and Schmidt number of 1280. The maximum mass transfer in the bends decreased from approximately 1.8 times the mass transfer in the upstream pipe when there was no separation distance between the bends to 1.7 times when there was a 1 D or 5 D length of pipe between the bends. The location of the maximum mass transfer was on the inner sidewall downstream of the second bend when there was no separation distance between the bends. This location changed to the inner wall at the beginning of the second bend when there was a 1 D long pipe between the bends, and to the inner sidewall at the end of the first bend when there was a 5 D long pipe between the bends.

Early Holocene estuary development of the Hesselø Bay area, southern Kattegat, Denmark and its implication for Ancylus Lake drainage

Science.gov (United States)

Bendixen, Carina; Boldreel, Lars Ole; Jensen, Jørn Bo; Bennike, Ole; Hübscher, Christian; Clausen, Ole Rønø

2017-12-01

High-resolution shallow seismic data, sediment core information, radiocarbon dating and sequence stratigraphy have been used to interpret the late glacial to early Holocene geological evolution of Hesselø Bay in the southern Kattegat, Denmark. A reconstruction of the early Holocene coastal environment and a description of coastal processes associated with a river outlet into the bay are presented. Weichselian glacial deposits form the lowermost interpreted unit, covered by late glacial (LG) and postglacial (PG, Holocene) sediments. A funnel-shaped estuary existed at the mouth of channels in the period 10.3-9.2 cal. ka BP; the channels drained water from south to north. The early PG is characterised by estuarine and coastal deposits. The early Holocene bars that developed in the estuary are preserved as morphological features on the present-day seabed, possibly as a result of rapid relative sea-level rise. The estuary existed simultaneously with the occurrence and drainage of the Ancylus Lake. The drainage of this lake occurred through the Dana River (palaeo-Great Belt channel) into the southern Kattegat and then into the study area. The level of the Ancylus Lake in the Baltic Sea region dropped significantly at about 10.2 cal. ka BP at the same time as the estuary developed in the Kattegat region. One outcome of the present study is an enhanced understanding of the Ancylus Lake drainage path. No evidence of major erosion is seen, which indicates non-catastrophic continuous water flow from the south without major drainage events of the Ancylus Lake to the southern Kattegat. During the Littorina transgression, coastal estuarine conditions characterized the Hesselø Bay area where elongated ridges formed a bar system. As the Littorina transgression continued, back-stepping of the bar system and coastline occurred. When the transgression breached the Great Belt threshold, flooding caused major erosion throughout the study area.

Bend testing for miniature disks

International Nuclear Information System (INIS)

Huang, F.H.; Hamilton, M.L.; Wire, G.L.

1982-01-01

A bend test was developed to obtain ductility measurements on a large number of alloy variants being irradiated in the form of miniature disks. Experimental results were shown to be in agreement with a theoretical analysis of the bend configuration. Disk specimens fabricated from the unstrained grip ends of previously tested tensile specimens were used for calibration purposes; bend ductilities and tensile ductilities were in good agreement. The criterion for estimating ductility was judged acceptable for screening purposes

Light Detection and Ranging (LiDAR and Multispectral Scanner (MSS Studies Examine Coastal Environments Influenced by Mining

Directory of Open Access Journals (Sweden)

W. Charles Kerfoot

2014-01-01

Full Text Available There are numerous examples of past and present mine disposal into freshwater and marine coastal bays and riverine environments. Due to its high spatial resolution and extended water penetration, coastal light detection and ranging (LiDAR, coupled with multispectral scanning (MSS, has great promise for resolving disturbed shoreline features in low turbidity environments. Migrating mine tailings present serious issues for Lake Superior and coastal marine environments. Previous investigations in Lake Superior uncovered a metal-rich “halo” around the Keweenaw Peninsula, related to past copper mining practices. For over a century, waste rock migrating from shoreline tailing piles has moved along extensive stretches of coastline, compromising critical fish breeding grounds, damming stream outlets, transgressing into wetlands and along recreational beaches and suppressing benthic invertebrate communities. In Grand (Big Traverse Bay, Buffalo Reef is an important spawning area for lake trout and whitefish threatened by drifting tailings. The movement of tailings into Buffalo Reef cobble fields may interfere with the hatching of fish eggs and fry survival, either by filling in crevices where eggs are deposited or by toxic effects on eggs, newly hatched larvae or benthic communities. Here, we show that the coastal tailing migration is not “out of sight, out of mind”, but clearly revealed by using a combination of LiDAR and MSS techniques.

Evaluating nonindigenous species management in a Bayesian networks derived relative risk framework for Padilla Bay, WA, USA.

Science.gov (United States)

Herring, Carlie E; Stinson, Jonah; Landis, Wayne G

2015-10-01

Many coastal regions are encountering issues with the spread of nonindigenous species (NIS). In this study, we conducted a regional risk assessment using a Bayesian network relative risk model (BN-RRM) to analyze multiple vectors of NIS introductions to Padilla Bay, Washington, a National Estuarine Research Reserve. We had 3 objectives in this study. The 1st objective was to determine whether the BN-RRM could be used to calculate risk from NIS introductions for Padilla Bay. Our 2nd objective was to determine which regions and endpoints were at greatest risk from NIS introductions. Our 3rd objective was to incorporate a management option into the model and predict endpoint risk if it were to be implemented. Eradication can occur at different stages of NIS invasions, such as the elimination of these species before being introduced to the habitat or removal of the species after settlement. We incorporated the ballast water treatment management scenario into the model, observed the risk to the endpoints, and compared this risk with the initial risk estimates. The model results indicated that the southern portion of the bay was at greatest risk because of NIS. Changes in community composition, Dungeness crab, and eelgrass were the endpoints most at risk from NIS introductions. The currents node, which controls the exposure of NIS to the bay from the surrounding marine environment, was the parameter that had the greatest influence on risk. The ballast water management scenario displayed an approximate 1% reduction in risk in this Padilla Bay case study. The models we developed provide an adaptable template for decision makers interested in managing NIS in other coastal regions and large bodies of water. © 2015 SETAC.

Fabrication of topology optimized photonic crystal waveguide Z-bend displaying large bandwidth with very low bend loss

DEFF Research Database (Denmark)

Harpøth, Anders; Frandsen, Lars Hagedorn; Kristensen, Martin

2004-01-01

We have designed, simulated and fabricated a photonic crystal waveguide Z-bend, which displays a total bend loss of ~1dB per bend in a wavelength range of more than 200nm. The fabricated component performs in excellent agreement with 3D finite-difference time-domain calculations....

Impact of salinity on the production of tomato along the coastal areas ...

African Journals Online (AJOL)

The coast of Benin lies on a wide bay in the Gulf of Guinea called the Bight of Benin, about 125 km between Togo and Nigeria. The coastal areas of Benin cover part of the cultivable lands of the country. A total of 15 tomato varieties were recorded in the areas of study. The characteristics of each variety grown under salinity ...

A Comprehensive Inventory of Alabama Coastal Zone Wetland Habitats (Swamps, Marshes, Submersed Grassbeds) from 1980 to 1982 (NCEI Accession 0161311)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Digitized maps of Mobile Bay and other coastal areas of Alabama, showing habitat types and species compositions of the vegetation in three broad categories of...

Bird surveys at Stokes Point and Philips Bay, Yukon in 1983. No. 40

Energy Technology Data Exchange (ETDEWEB)

Dickson, D L; Dickson, H L; Aiudi, G M

1988-01-01

The distribution, abundance, and habitat preferences of birds were studied at Stokes Point, Phillips Bay and King Point in the northern Yukon in 1983. These data were gathered to assist in decisions about future development of a port to support marine drilling activities in the Beaufort Sea. Nesting bird densities at Stokes Point were similar to those found elsewhere on the Yukon Coastal Plain due to the similarity in habitat. The lagoon at Stokes Point was locally important to molting ducks. Several species occurred in higher densities at Phillips Bay than elsewhere on the Plain, mainly due to the deltas and spits created by rivers flowing into the Bay. These deltas were locally important to such species as molting non-breeding tundra swans, Canada geese, and ducks. During ground surveys in June, habitat was classified into 13 types and the nesting density for each bird species calculated for each habitat type. Overall bird densities were more than 3 times higher in lowland than in upland habitats. Passerine densities and species were highest in the tall shrub type of habitat found primarily in stream and river valleys. The Yukon Coastal Plain is an important nesting area for the stilt sandpiper, which has a limited breeding range. The Plain is also nationally important for nesting long-billed dowitchers and yellow wagtails, both fairly common in the study area but with very limited breeding distribution within Canada. The Plain is also internationally important to fall staging snow geese. 38 refs., 17 figs., 35 tabs.

[Benthic flora and reproduction of Batophora spp. algae (Chlorophyta: Dasycladaceae) in a polluted coastal lagoon (Chetumal Bay, Mexico)].

Science.gov (United States)

Quan-Young, L I; Jiménez-Flores, S G; Espinoza-Avalos, J

2006-06-01

The benthic flora, and the vegetative and reproductive characters of the algae Batophora oerstedii and B. occidentalis (Chlorophyta) were recorded from five sites of Chetumal Bay, Quintana Roo, Mexico. A sewage gradient has been reported along those sites. Plants were sampled in May and October 1999, which corresponded to dry and rainy seasons, respectively. Forty taxa were found, 11 are new records for the Chetumal Bay, and 6 are new records for the Mexican Caribbean. Enteromorpha species were present in sites known as rich in organic matter (both from anthropogenic and natural sources). Batophora spp. is the dominant algae in all Chetumal Bay. However, it was absent next to sewage outfalls. The morphological characters of B. oerstedii and B. occidentalis did not change significantly along the sites reported as polluted. The length and width of gametophores, as well as the diameter of the gametangia were clearly different for both species. Different reproductive strategies may help B. oerstedii and B. occidentalis to closely coexist in the Chetumal Bay.

76 FR 81992 - PPL Bell Bend, LLC; Combined License Application for Bell Bend Nuclear Power Plant; Exemption

Science.gov (United States)

2011-12-29

... License Application for Bell Bend Nuclear Power Plant; Exemption 1.0 Background PPL Bell Bend, LLC... for Nuclear Power Plants.'' This reactor is to be identified as Bell Bend Nuclear Power Plant (BBNPP... based upon the U.S. EPR reference COL (RCOL) application for UniStar's Calvert Cliffs Nuclear Power...

NASA COAST and OCEANIA Airborne Missions Support Ecosystem and Water Quality Research in the Coastal Zone

Science.gov (United States)

Guild, Liane; Kudela, Raphael; Hooker, Stanford; Morrow, John; Russell, Philip; Palacios, Sherry; Livingston, John M.; Negrey, Kendra; Torres-Perez, Juan; Broughton, Jennifer

2014-01-01

NASA has a continuing requirement to collect high-quality in situ data for the vicarious calibration of current and next generation ocean color satellite sensors and to validate the algorithms that use the remotely sensed observations. Recent NASA airborne missions over Monterey Bay, CA, have demonstrated novel above- and in-water measurement capabilities supporting a combined airborne sensor approach (imaging spectrometer, microradiometers, and a sun photometer). The results characterize coastal atmospheric and aquatic properties through an end-to-end assessment of image acquisition, atmospheric correction, algorithm application, plus sea-truth observations from state-of-the-art instrument systems. The primary goal is to demonstrate the following in support of calibration and validation exercises for satellite coastal ocean color products: 1) the utility of a multi-sensor airborne instrument suite to assess the bio-optical properties of coastal California, including water quality; and 2) the importance of contemporaneous atmospheric measurements to improve atmospheric correction in the coastal zone. The imaging spectrometer (Headwall) is optimized in the blue spectral domain to emphasize remote sensing of marine and freshwater ecosystems. The novel airborne instrument, Coastal Airborne In-situ Radiometers (C-AIR) provides measurements of apparent optical properties with high dynamic range and fidelity for deriving exact water leaving radiances at the land-ocean boundary, including radiometrically shallow aquatic ecosystems. Simultaneous measurements supporting empirical atmospheric correction of image data are accomplished using the Ames Airborne Tracking Sunphotometer (AATS-14). Flight operations are presented for the instrument payloads using the Center for Interdisciplinary Remotely-Piloted Aircraft Studies (CIRPAS) Twin Otter flown over Monterey Bay during the seasonal fall algal bloom in 2011 (COAST) and 2013 (OCEANIA) to support bio-optical measurements of

A transparent bending-insensitive pressure sensor

Science.gov (United States)

Lee, Sungwon; Reuveny, Amir; Reeder, Jonathan; Lee, Sunghoon; Jin, Hanbit; Liu, Qihan; Yokota, Tomoyuki; Sekitani, Tsuyoshi; Isoyama, Takashi; Abe, Yusuke; Suo, Zhigang; Someya, Takao

2016-05-01

Measuring small normal pressures is essential to accurately evaluate external stimuli in curvilinear and dynamic surfaces such as natural tissues. Usually, sensitive and spatially accurate pressure sensors are achieved through conformal contact with the surface; however, this also makes them sensitive to mechanical deformation (bending). Indeed, when a soft object is pressed by another soft object, the normal pressure cannot be measured independently from the mechanical stress. Here, we show a pressure sensor that measures only the normal pressure, even under extreme bending conditions. To reduce the bending sensitivity, we use composite nanofibres of carbon nanotubes and graphene. Our simulations show that these fibres change their relative alignment to accommodate bending deformation, thus reducing the strain in individual fibres. Pressure sensitivity is maintained down to a bending radius of 80 μm. To test the suitability of our sensor for soft robotics and medical applications, we fabricated an integrated sensor matrix that is only 2 μm thick. We show real-time (response time of ∼20 ms), large-area, normal pressure monitoring under different, complex bending conditions.

Meso-scale atmospheric events promote phytoplankton blooms in the coastal Bay of Bengal

Digital Repository Service at National Institute of Oceanography (India)

Maneesha, K.; Sarma, V.V.S.S.; Reddy, N.P.C.; Sadhuram, Y.; Murty, T.V.R.; Sarma, V.V.; DileepKumar, M.

mixing does not cool SST in the post monsoon north Bay of Bengal; Atmos. Sci. Letts. 9 1–6. Senjyu T and Watanabe T 1999 A sudden temperature decrease along the Sanin coast induced by a typhoon; Umi to Sora 75 1–8 (in Japanese with English abstract...

Uncertainty in model predictions of Vibrio vulnificus response to climate variability and change: a Chesapeake Bay case study.

Directory of Open Access Journals (Sweden)

Erin A Urquhart

Full Text Available The effect that climate change and variability will have on waterborne bacteria is a topic of increasing concern for coastal ecosystems, including the Chesapeake Bay. Surface water temperature trends in the Bay indicate a warming pattern of roughly 0.3-0.4°C per decade over the past 30 years. It is unclear what impact future warming will have on pathogens currently found in the Bay, including Vibrio spp. Using historical environmental data, combined with three different statistical models of Vibrio vulnificus probability, we explore the relationship between environmental change and predicted Vibrio vulnificus presence in the upper Chesapeake Bay. We find that the predicted response of V. vulnificus probability to high temperatures in the Bay differs systematically between models of differing structure. As existing publicly available datasets are inadequate to determine which model structure is most appropriate, the impact of climatic change on the probability of V. vulnificus presence in the Chesapeake Bay remains uncertain. This result points to the challenge of characterizing climate sensitivity of ecological systems in which data are sparse and only statistical models of ecological sensitivity exist.

Dinoflagellate cysts from surface sediments of Saldanha Bay, South Africa: an indication of the potential risk of harmful algal blooms

CSIR Research Space (South Africa)

Joyce, LB

2005-02-01

Full Text Available Africa bZoology Department, University Cape Town, Rondebosch 7701, Cape Town, South Africa cCouncil for Scientific and Industrial Research, P.O. Box 320, Stellenbosch 7759, South Africa Received 14 May 2004; received in revised form 21 July 2004; accepted... 15 August 2004 Abstract The distribution and abundance of dinoflagellate cysts from recent coastal sediments in Saldanha Bay, was investigated, and compared to the cyst assemblages of the adjacent coastal upwelling system as reflected in the sediments...

Evaluating Satellite and Supercomputing Technologies for Improved Coastal Ecosystem Assessments

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McCarthy, Matthew James

Water quality and wetlands represent two vital elements of a healthy coastal ecosystem. Both experienced substantial declines in the U.S. during the 20th century. Overall coastal wetland cover decreased over 50% in the 20th century due to coastal development and water pollution. Management and legislative efforts have successfully addressed some of the problems and threats, but recent research indicates that the diffuse impacts of climate change and non-point source pollution may be the primary drivers of current and future water-quality and wetland stress. In order to respond to these pervasive threats, traditional management approaches need to adopt modern technological tools for more synoptic, frequent and fine-scale monitoring and assessment. In this dissertation, I explored some of the applications possible with new, commercial satellite imagery to better assess the status of coastal ecosystems. Large-scale land-cover change influences the quality of adjacent coastal water. Satellite imagery has been used to derive land-cover maps since the 1960's. It provides multiple data points with which to evaluate the effects of land-cover change on water quality. The objective of the first chapter of this research was to determine how 40 years of land-cover change in the Tampa Bay watershed (6,500 km2) may have affected turbidity and chlorophyll concentration - two proxies for coastal water quality. Land cover classes were evaluated along with precipitation and wind stress as explanatory variables. Results varied between analyses for the entire estuary and those of segments within the bay. Changes in developed land percent cover best explained the turbidity and chlorophyll-concentration time series for the entire bay (R2 > 0.75, p Ocean-color satellite imagery was used to derive proxies for coastal water with near-daily satellite observations since 2000. The goal of chapter two was to identify drivers of turbidity variability for 11 National Estuary Program water bodies

Towards Sustainable Ambon Bay: Evaluation of Solid Waste Management in Ambon City

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Maryati, S.; Miharja, M.; Iscahyono, A. F.; Arsallia, S.; Humaira, AN S.

2017-07-01

Ambon Bay is a strategic area in the context of regional economic development, however it also faced environmental problems due to economic development and the growth of population. One of the environmental problems in the Ambon Bay is the growing solid waste which in turn lowers the quality of the water. The purpose of this study is to evaluate solid waste management in the Ambon City and propose recommendation in order to reduce solid waste in the Ambon Bay. The analytical method used is descriptive analysis by comparing a number of criteria based on the concept of solid waste management in coastal region with the current conditions of solid waste management in Ambon City. Criteria for waste management are divided into generation, storage, collection, transport, transfer and disposal. From the results of analysis, it can be concluded that the components of solid waste management at transport, transfer, and disposal level are generally still adequate, but solid waste management at source, storage and collection level have to be improved.

Contribution of chronic petroleum inputs to Narragansett Bay and Rhode Island Sound sediments

Energy Technology Data Exchange (ETDEWEB)

Van Vleet, E S; Quin, J G

1978-05-01

Sediment cores from Narragansett Bay and Rhode Island Sound have been analyzed for petroleum hydrocarbons and compared with a relatively unpolluted sediment core from the Gulf of Maine. The sediments were analyzed for unbound hydrocarbons, hydrocarbons bound or closely associated with humic substances, and residual hydrocarbons bound or closely associated with the clay mineral or kerogen matrix. Results indicated that in general 90-100% of the hydrocarbons were in the unbound form and could be easily extracted with organic solvents. The petroleum hydrocarbons decreased with depth at all stations. Biogenic hydrocarbons (nC/sub 25/, nC/sub 27/, nC/sub 29/, and nC/sub 31/) made up an increasingly greater percentage of the total with increasing depth. The hydrocarbons in the Narragansett Bay sediments and near surface Rhode Island Sound sediments strongly resembled the hydrocarbons previously reported for the Providence River and upper Narragansett Bay. These petroleum-like hydrocarbons were shown to be largely introduced to the river and bay through chronic inputs from a municipal wastewater treatment plant. These hydrocarbons then undergo sedimentation throughout the entire bay and into Rhode Island Sound. Preliminary calculations indicate that over 0.2 million t (tonne) of petroleum hydrocarbons may be transported to the marine environment annually from municipal treatment plants. Most of these hydrocarbons appear to accumulate in estuarine and coastal sediments.

Numerical simulation of hydrodynamic and water quality effects of shoreline changes in Bohai Bay

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Jia, Han; Shen, Yongming; Su, Meirong; Yu, Chunxue

2018-02-01

This study uses the HD and Ecolab modules of MIKE to simulate the hydrodynamic and water quality and predict the influence of shoreline changes in Bohai Bay, China. The study shows that shoreline changes weaken the residual current and generate a counter-clockwise circulation south of Huanghua Port, thereby resulting in weak water exchange capacity and low pollutant-diffusing capacity. Shoreline changes reduce the area of Bohai Bay, resulting in a smaller tidal prism and further weakening the water exchange capacity. This situation is not conducive to the diffusion of pollutants, and therefore may lead to increased water pollution in the bay. Shoreline changes hinder the spread of runoff, weaken the dilution effect of the river on seawater, and block the spread of coastal residual current, thereby resulting in increased salinity near the reclamation area. Shoreline changes lead to an increase in PO4-P concentration and decrease in DIN concentration. The value of N/P near the project decreases, thereby weakening the phosphorus-limited effect.

Effects of Nutrient Dynamics, Light and Temperature on the Patchiness of Phytoplankton and Primary Production in the Estuarine and Coastal Zones of Liaodong Bay, China: A Typical Case Study

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Pei, S.; Laws, E. A.; Ye, S.

2017-12-01

Fluvial inputs of nutrients and efficient nutrient recycling mechanisms make estuarine and coastal zones highly productive bodies of water. For the same reasons, they are susceptible to eutrophication problems. In China, eutrophication problems along coasts are becoming serious because of discharges of domestic sewage and industrial wastewater and runoff of agricultural fertilizer. Addressing these problems requires an informed assessment of the factors that controlling algal production. Our study aims at determining the factors that controlling patchiness of phytoplankton and primary production in Liaodong Bay, China that receives large inputs of nutrients from human activities in its watershed, and examining the variation patterns of phytoplankton photosynthesis under both stressors of climate change and human activities. Results of our field study suggest that nutrient concentrations were above growth-rate-saturating concentrations throughout Liaodong bay, with the possible exception of phosphate at some stations. This assessment was consistent with the results of nutrient enrichment experiments and the values of light-saturated photosynthetic rates and areal photosynthetic rates. Two large patches of high biomass and production with dimensions on the order of 10 km reflect the effects of water temperature and variation of light penetration restricted by water turbidity. To examine the effects of irradiance and temperature on light-saturated photosynthetic rates normalized to chlorophyll a concentrations (Popt), light-conditioned Popt values were modeled as a function of the temperature with a satisfactory fit to our field data (R2 = 0.60, p = 0.003). In this model, light-conditioned Popt values increased with temperatures from 22°C to roughly 25°C but declined precipitously at higher temperatures. The relatively high Popt values and low ratios of light absorbed to photosynthesis at coastal stations suggest the highly efficient usage of absorbed light by

Airborne Mission Concept for Coastal Ocean Color and Ecosystems Research

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Guild, Liane S.; Hooker, Stanford B.; Morrow, John H.; Kudela, Raphael M.; Palacios, Sherry L.; Torres Perez, Juan L.; Hayashi, Kendra; Dunagan, Stephen E.

2016-01-01

NASA airborne missions in 2011 and 2013 over Monterey Bay, CA, demonstrated novel above- and in-water calibration and validation measurements supporting a combined airborne sensor approach (imaging spectrometer, microradiometers, and a sun photometer). The resultant airborne data characterize contemporaneous coastal atmospheric and aquatic properties plus sea-truth observations from state-of-the-art instrument systems spanning a next-generation spectral domain (320-875 nm). This airborne instrument suite for calibration, validation, and research flew at the lowest safe altitude (ca. 100 ft or 30 m) as well as higher altitudes (e.g., 6,000 ft or 1,800 m) above the sea surface covering a larger area in a single synoptic sortie than ship-based measurements at a few stations during the same sampling period. Data collection of coincident atmospheric and aquatic properties near the sea surface and at altitude allows the input of relevant variables into atmospheric correction schemes to improve the output of corrected imaging spectrometer data. Specific channels support legacy and next-generation satellite capabilities, and flights are planned to within 30 min of satellite overpass. This concept supports calibration and validation activities of ocean color phenomena (e.g., river plumes, algal blooms) and studies of water quality and coastal ecosystems. The 2011 COAST mission flew at 100 and 6,000 ft on a Twin Otter platform with flight plans accommodating the competing requirements of the sensor suite, which included the Coastal-Airborne In-situ Radiometers (C-AIR) for the first time. C-AIR (Biospherical Instruments Inc.) also flew in the 2013 OCEANIA mission at 100 and 1,000 ft on the Twin Otter below the California airborne simulation of the proposed NASA HyspIRI satellite system comprised of an imaging spectrometer and thermal infrared multispectral imager on the ER-2 at 65,000 ft (20,000 m). For both missions, the Compact-Optical Profiling System (Biospherical

Responses of water environment to tidal flat reduction in Xiangshan Bay: Part I hydrodynamics

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Li, Li; Guan, Weibing; Hu, Jianyu; Cheng, Peng; Wang, Xiao Hua

2018-06-01

Xiangshan Bay consists of a deep tidal channel and three shallow inlets. A large-scale tidal flat has been utilized through coastal construction. To ascertain the accumulate influences of these engineering projects upon the tidal dynamics of the channel-inlets system, this study uses FVCOM to investigate the tides and flow asymmetries of the bay, and numerically simulate the long-term variations of tidal dynamics caused by the loss of tidal flats. It was found that the reduction of tidal flat areas from 1963 to 2010 slightly dampened M2 tidal amplitudes (0.1 m, ∼6%) and advanced its phases by reducing shoaling effects, while amplified M4 tidal amplitudes (0.09 m, ∼27%) and advanced its phases by reducing bottom friction, in the inner bay. Consequently, the ebb dominance was dampened indicated by reduced absolute value of elevation skewness (∼20%) in the bay. The tides and tidal asymmetry were impacted by the locations, areas and slopes of the tidal flats through changing tidal prism, shoaling effect and bottom friction, and consequently impacted tidal duration asymmetry in the bay. Tides and tidal asymmetry were more sensitive to the tidal flat at the head of the bay than the side bank. Reduced/increased tidal flat slopes around the Tie inlet dampened the ebb dominance. Tidal flat had a role in dissipating the M4 tide rather than generating it, while the advection only play a secondary role in generating the M4 tide. The full-length tidal flats reclamation would trigger the reverse of ebb to flood dominance in the bay. This study would be applicable for similar narrow bays worldwide.

Occipital bending in depression.

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Maller, Jerome J; Thomson, Richard H S; Rosenfeld, Jeffrey V; Anderson, Rodney; Daskalakis, Zafiris J; Fitzgerald, Paul B

2014-06-01

There are reports of differences in occipital lobe asymmetry within psychiatric populations when compared with healthy control subjects. Anecdotal evidence and enlarged lateral ventricles suggests that there may also be a different pattern of curvature whereby one occipital lobe wraps around the other, termed 'occipital bending'. We investigated the prevalence of occipital bending in 51 patients with major depressive disorder (males mean age = 41.96 ± 14.00 years, females mean age = 40.71 ± 12.41 years) and 48 age- and sex-matched healthy control subjects (males mean age = 40.29 ± 10.23 years, females mean age = 42.47 ± 14.25 years) and found the prevalence to be three times higher among patients with major depressive disorder (18/51, 35.3%) when compared with control subjects (6/48, 12.5%). The results suggest that occipital bending is more common among patients with major depressive disorder than healthy subjects, and that occipital asymmetry and occipital bending are separate phenomena. Incomplete neural pruning may lead to the cranial space available for brain growth being restricted, or ventricular enlargement may exacerbate the natural occipital curvature patterns, subsequently causing the brain to become squashed and forced to 'wrap' around the other occipital lobe. Although the clinical implications of these results are unclear, they provide an impetus for further research into the relevance of occipital bending in major depression disorder. © The Author (2014). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Coastal and Riverine Flood Forecast Model powered by ADCIRC

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Khalid, A.; Ferreira, C.

2017-12-01

Coastal flooding is becoming a major threat to increased population in the coastal areas. To protect coastal communities from tropical storms & hurricane damages, early warning systems are being developed. These systems have the capability of real time flood forecasting to identify hazardous coastal areas and aid coastal communities in rescue operations. State of the art hydrodynamic models forced by atmospheric forcing have given modelers the ability to forecast storm surge, water levels and currents. This helps to identify the areas threatened by intense storms. Study on Chesapeake Bay area has gained national importance because of its combined riverine and coastal phenomenon, which leads to greater uncertainty in flood predictions. This study presents an automated flood forecast system developed by following Advanced Circulation (ADCIRC) Surge Guidance System (ASGS) guidelines and tailored to take in riverine and coastal boundary forcing, thus includes all the hydrodynamic processes to forecast total water in the Potomac River. As studies on tidal and riverine flow interaction are very scarce in number, our forecast system would be a scientific tool to examine such area and fill the gaps with precise prediction for Potomac River. Real-time observations from National Oceanic and Atmospheric Administration (NOAA) and field measurements have been used as model boundary feeding. The model performance has been validated by using major historical riverine and coastal flooding events. Hydrodynamic model ADCIRC produced promising predictions for flood inundation areas. As better forecasts can be achieved by using coupled models, this system is developed to take boundary conditions from Global WaveWatchIII for the research purposes. Wave and swell propagation will be fed through Global WavewatchIII model to take into account the effects of swells and currents. This automated forecast system is currently undergoing rigorous testing to include any missing parameters which

Rapid Crustal Uplift at Birch Bay, Washington

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Sherrod, B. L.; Kelsey, H. M.; Blakely, R. J.

2010-12-01

Geomorphology and coastal marsh stratigraphy suggest late Holocene uplift of the shoreline at Birch Bay, located northwest of Bellingham, Washington, during an earthquake on a shallow fault. LiDAR images show a raised, late Holocene shoreline along Birch Bay, with ~1 m of elevation difference between the modern shoreline and the inferred paleoshoreline. Commercial seismic reflection images reveal an anticline in Tertiary and possibly Quaternary deposits underlying Birch Bay. NW-trending magnetic anomalies are likely associated with the Birch Bay anticline and other nearby structures. Taken together, the geophysical data and lidar images suggest uplift of young deposits along a NW-trending blind reverse fault. Stratigraphy from Terrell Creek marsh, located just south of Birch Bay, shows freshwater peat buried by lower intertidal muds, indicating local submergence ~1300 yr BP. Stratigraphy of a 70-cm sediment core from Birch Bay marsh, sitting astride the anticline imaged with seismic reflection data, shows mud buried by detrital peat. One radiocarbon age from the core places the abrupt change from mud to peat prior to 1520-1700 yr BP. We divide fossil diatom assemblages straddling the mud-peat contact at Birch Bay into three zones. The oldest zone consists primarily of intertidal and marine diatoms, dominated by Paralia sulcata, Scoleoneis tumida, Grammataphora oceanica, and Gyrosigma balticum. An intermediate zone, beginning at the sharp contact between mud and overlying peat, consists of a mixture of brackish marsh and freshwater species, dominated by Diploneis interrupta, with lesser amounts of Aulacoseira sp., Pinnularia viridis, Eunotia pectinalis, and Paralia sulcata. A third and youngest zone lies in the upper half of the peat and is dominated by poorly preserved freshwater diatoms, mostly Aulacoseira cf. crassapuntata, Pinnularia viridis, P. maior, Eunotia pectinalis, and E. praerupta. Paleoecological inferences, based on distributions of modern diatoms

Study of characteristic of tsunami base on the coastal morphology in north Donggala, Central Sulawesi

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Rahmadaningsi, W. S. N.; Assegaf, A. H.; Setyonegoro, W.; Paharuddin

2018-03-01

The northern arm of Sulawesi potentials to generate earthquake and Tsunami due to the existence of subduction zone in sulawesi sea. It makes the North Donggala as an area with active seismicity. One of the earthquake and Tsunami events occurred is the earthquake and tsunami of Toli-Toli 1996 (M 7.9) causing 9 people are killed and severe damage in Tonggolobibi, Siboang, and Balukang. This earthquake induced tsunami runup of 3.4 m and inundated as far as 400 meters. The aims of this study is to predict runup and inundation area using numerical model and to find out the characteristics of Tsunami wave on straight, bay and cape shape coastal morphology and slopes of coastal. The data in this research consist of are the Etopo2 bathymetry data in data obtained from NOAA (National Oceanic and Atmospheric Administration), Toli-toli’s main earthquakes focal mechanism data 1st January1996 from GCMT (Global Centroid Moment Tensor), the data gained from the SRTM (Shuttle Radar Topography Mission) data 30 m and land cover data in 1996 from Ministry of environment and forestry . Single fault model is used to predict the high of tsunami run-up and to inundation area along Donggala coastal area. Its reviewed by morphology of coastal area that higher run up shows occurs at coastline type like bay have higher run up compare to area with cape and straight coastline. The result shows that the slopes have negative or contras correlation with Tsunami runup and its inundation area.

A University-Hosted Program in Pursuit of Coastal Sustainability: The Case of Tokyo Bay

Directory of Open Access Journals (Sweden)

Osamu Baba

2013-09-01

Full Text Available This study presents a unique way by which a university program can contribute to capacity development for coastal sustainability. The program is steered by a working group of volunteer faculty members, having different academic backgrounds, in collaboration with students and marine professionals, including fisherfolk and environment education interpreters. Although the program began with conventional educational ideas and style, its practical framework evolved to include interactive activities with collaborators in the community, all of which were geared toward social learning. The combination of service learning and participatory action research (PAR was proven to be an adequate approach to link higher education for sustainable development (HESD and university-community partnerships and to promote learning for coastal sustainability. Challenges identified include (1 ensuring continuity of learning and (2 reducing the heavy workload of faculty members involved in program preparation and coordination. The authors would like to emphasize the possibilities offered by the engagement of scholarship in the capacity development for coastal sustainability by focusing on community-based efforts.

33 CFR 100.124 - Maggie Fischer Memorial Great South Bay Cross Bay Swim, Great South Bay, New York.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Maggie Fischer Memorial Great South Bay Cross Bay Swim, Great South Bay, New York. 100.124 Section 100.124 Navigation and Navigable... NAVIGABLE WATERS § 100.124 Maggie Fischer Memorial Great South Bay Cross Bay Swim, Great South Bay, New York...

Changes on the coastline of buenaventura bay (colombian pacific) and its relationship with the climatic conditions

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Coca-Domínguez, Oswaldo; Ricaurte-Villota, Constanza; Andres Ordoñez, Silvio

2016-04-01

Some authors point out that the variability of a coastal system is the response of physical factors (climate, waves, currents, wind, etc.) or combination of some of them, for example long-term variations in the relationship between climate and supply of sedimentary material. For Colombian Pacific coast it has been said that the regimen of meso-tidal is one of the agents that contribute to changes in the morphology of the littoral zone. Between 2012-2015 was conducted a research in the mouth of Buenaventura Bay (Colombia Pacific coast), using two stations: Soldado point (southern point of the bay) and Bazan point (the northern point of the bay), for those stations the digital elevation model (DEM) was performed using a DGPS with technology GNSS the recent evolution of the coastline and changes in volume of sand from beaches for two scalar approaches were determined: annual and intra-annual. The use of ArcGIS 3D Analyst in the DEMs allowed to calculate the cubic area between the raised surfaces each month. Changes in the coastline were made using Digital Shoreline Analysis System (DSAS) an ARCGIS extension. We used zonal and meridional components of the wind data near the coast from WindSat, rainfall and sea level anomaly data from the database AVISO (Archiving, Validation and Interpretation of Satellite Oceanographic), and sea level pressure (SLP) from NCEP/NCAR (National Center for Environmental Prediction/ National Center for Atmospheric Research), in collaboration with the National Oceanic and Atmospheric Administration (NOAA). Finally, climatic variables were correlated with the rates of coastal erosion and changes in sand volume of the beaches, because wind and precipitation are some of the factors in sediment transport. The study showed erosion rates with negative values in 2014 and 2015 that represent loss of land, the intra-annual variability in September and October were the highest loss of land, this coincides with the values of the highest tides of the

San Francisco Bay, California 1/3 Arc-second MHW Coastal Digital Elevation Model

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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. These integrated...

Analysis of coastal protection under rising flood risk

Directory of Open Access Journals (Sweden)

Megan J. Lickley

2014-01-01

Full Text Available Infrastructure located along the U.S. Atlantic and Gulf coasts is exposed to rising risk of flooding from sea level rise, increasing storm surge, and subsidence. In these circumstances coastal management commonly based on 100-year flood maps assuming current climatology is no longer adequate. A dynamic programming cost–benefit analysis is applied to the adaptation decision, illustrated by application to an energy facility in Galveston Bay. Projections of several global climate models provide inputs to estimates of the change in hurricane and storm surge activity as well as the increase in sea level. The projected rise in physical flood risk is combined with estimates of flood damage and protection costs in an analysis of the multi-period nature of adaptation choice. The result is a planning method, using dynamic programming, which is appropriate for investment and abandonment decisions under rising coastal risk.

On the formation of coastal polynyas in the area of Commonwealth Bay, Eastern Antarctica

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Wendler, Gerd; Gilmore, Dan; Curtis, Jan

Antarctica's King George V Land and Adélie Land were first explored by Sir Douglas Mawson and his party during their 1911-1913 expedition. They were astounded by the strength of the katabatic wind, which is so dominant in this area. These strong offshore winds can move the sea ice away from shore, forming coastal polynya, not only in summer but even in midwinter. Poor visibility due to darkness and frequently occurring blowing snow make the study of these polynyas from land-based observations difficult. Recently, coverage of this area by synthetic aperture radar (SAR) satellite imagery, which has a high resolution of 40 m (pixel size 12.5 m), gave additional insight into the characteristics of these polynyas. This high resolution is needed because the width of the polynya is small (10 km or so). Furthermore, of special importance is the fact that SAR data can be obtained during darkness and overcast conditions. Following original Russian work, we modified a simple model for wind-driven coastal polynyas, using actual meteorological data from our coastal automatic weather stations as input. Using mean monthly data for the stations, we show that coastal polynyas are to be expected in the windiest area (Cape Denison-Port Martin); while to the west (Dumont d'Urville) and east (Penguin Point), the average conditions do not produce them. Here, they occur only during strong and long-lasting storms. Our observational data of the polynyas as viewed from SAR and advanced very high resolution radiometer (AVHRR) confirm these findings.

A crisis in waste management, economic vitality, and a coastal marine environment: Boston Harbor and Massachusetts Bay

Science.gov (United States)

Manheim, F.T.; Butman, B.

1994-01-01

Discharge of sewage sludge and effluent from 43 communities in the greater Boston metropolitan area has helped make the harbor one of the most polluted in the nation. As part of a court-mandated plan to end pollution of the harbor, effluent will no longer be discharged into the harbor, but instead, by 1995 it will be discharged into Massachusetts Bay through a record-long 15.34 km tunnel. By the year 2000 all of the sewage is scheduled to recive full secondary treatment. The public is concerned about long-term effects of the new ocean outfall on the environment, including Cape Cod Bay and Stellwagen Bank, which is an important habitat for whales and a newly designated national marine sanctuary. The bay has been additionally stressed by dumping of low-level radioactive and other hazardous wastes during the 1950s and 1960s. -from Authors

Sustainability Partnerships for the Governance of Coastal Resources in Tanzania

DEFF Research Database (Denmark)

Katikiro, Robert; Kweka, Opportuna; Namkesa, Faraja

The paper examines the experience of sustainability partnerships for the management of coastal resources in Tanzania. It identifies key actors and governance dynamics, with focus on decentralization processes, legitimacy-building and participation of local communities. The paper first provides a ...... of ongoing research under the New Partnerships for Sustainability project (NEPSUS), it provides guidance on research gaps in specific relation to the Mnazi Bay Ruvuma Estuary Marine Park (MBREMP) and selected BMUs in Mtwara region, Southern Tanzania....

Holocene depositional history of a large glaciated estuary, Penobscot Bay, Maine

Science.gov (United States)

Knebel, H.J.

1986-01-01

Data from seismic-reflection profiles, sidescan sonar images, and sediment samples reveal the Holocene depositional history of the large (1100 km2) glaciated Penobscot Bay estuary of coastal Maine. Previous work has shown that the late Wisconsinan ice sheet retreated from the three main passages of the bay between 12,700 and 13,500 years ago and was accompanied by a marine transgression during which ice and sea were in contact. Isostatic recovery of the crust caused the bay to emerge during the immediate postglacial period, and relative sea level fell to at least -40 m sometime between 9000 and 11,500 years ago. During lowered sea level, the ancestral Penobscot River flowed across the subaerially exposed head of the bay and debouched into Middle Passage. Organic-matter-rich mud from the river was deposited rapidly in remnant, glacially scoured depressions in the lower reaches of Middle and West Passages behind a shallow (???20 m water depth) bedrock sill across the bay mouth. East Passage was isolated from the rest of the bay system and received only small amounts of locally derived fine-grained sediments. During the Holocene transgression that accompanied the eustatic rise of sea level, the locus of sedimentation shifted to the head of the bay. Here, heterogeneous fluvial deposits filled the ancestral valley of the Penobscot River as base level rose, and the migrating surf zone created a gently dipping erosional unconformity, marked by a thin (energy conditions and the waning influence of the Penobscot River at the head of the bay. In contrast, relatively thick (up to 25 m) silty clays accumulated within a subbottom trough in the western half of the bay head. This deposit apparently developed late in the transgression after sea level had reached -20 m and after the westward transport of fine-grained sediments from the Penobscot River had been established. During and since the late Holocene transgression of sea level, waves and currents have eroded, reworked, and

Perryville and Ivanof Bay, Alaska 1/3 arc-second Coastal Digital Elevation Model