Wetlands as principal zones of methylmercury production in southern Louisiana and the Gulf of Mexico region

Energy Technology Data Exchange (ETDEWEB)

Hall, B.D. [Environmental Chemistry and Technology Program, University of Wisconsin-Madison, Madison, WI 53706 (United States); Department of Biology, University of Regina, 3737 Wascana Parkway, Regina, SK, S4S 0A2 (Canada)], E-mail: britt.hall@uregina.ca; Aiken, G.R. [United States Geological Survey, 3215 Marine Street, Boulder, CO 80303 (United States); Krabbenhoft, D.P. [United States Geological Survey, 8505 Research Way, Middleton, WI 53562 (United States); Marvin-DiPasquale, M. [United States Geological Survey, 345 Middlefield Road, Menlo Park, CA 94025 (United States); Swarzenski, C.M. [United States Geological Survey, Suite 120, 3535 S. Sherwood Forest Blvd., Baton Rouge, LA 70816 (United States)

2008-07-15

It is widely recognized that wetlands, especially those rich in organic matter and receiving appreciable atmospheric mercury (Hg) inputs, are important sites of methylmercury (MeHg) production. Extensive wetlands in the southeastern United States have many ecosystem attributes ideal for promoting high MeHg production rates; however, relatively few mercury cycling studies have been conducted in these environments. We conducted a landscape scale study examining Hg cycling in coastal Louisiana (USA) including four field trips conducted between August 2003 and May 2005. Sites were chosen to represent different ecosystem types, including: a large shallow eutrophic estuarine lake (Lake Pontchartrain), three rivers draining into the lake, a cypress-tupelo dominated freshwater swamp, and six emergent marshes ranging from a freshwater marsh dominated by Panicum hemitomon to a Spartina alterniflora dominated salt marsh close to the Gulf of Mexico. We measured MeHg and total Hg (THg) concentrations, and ancillary chemical characteristics, in whole and filtered surface water, and filtered porewater. Overall, MeHg concentrations were greatest in surface water of freshwater wetlands and lowest in the profundal (non-vegetated) regions of the lake and river mainstems. Concentrations of THg and MeHg in filtered surface water were positively correlated with the highly reactive, aromatic (hydrophobic organic acid) fraction of dissolved organic carbon (DOC). These results suggest that DOC plays an important role in promoting the mobility, transport and bioavailability of inorganic Hg in these environments. Further, elevated porewater concentrations in marine and brackish wetlands suggest coastal wetlands along the Gulf Coast are key sites for MeHg production and may be a principal source of MeHg to foodwebs in the Gulf of Mexico. Examining the relationships among MeHg, THg, and DOC across these multiple landscape types is a first step in evaluating possible links between key zones for

Hydrobiological Survey of the Bahir Dar Gulf of Lake Tana, Ethiopia

African Journals Online (AJOL)

FIRST LADY

lake and for monitoring changes taking place as a consequence of human developmental ... peculiar biodiversity and the increasing threats of expanding urban habitation ..... communities and their role in the food web of Lake Tana, Ethiopia.

Decadal oscillation of lakes and aquifers in the upper Great Lakes region of North America: hydroclimatic implications

Science.gov (United States)

Watras, C.J.; Read, J.S.; Holman, K.D.; Liu, Z.; Song, Y.-Y.; Watras, A.J.; Morgan, S.; Stanley, E.H.

2014-01-01

We report a unique hydrologic time-series which indicates that water levels in lakes and aquifers across the upper Great Lakes region of North America have been dominated by a climatically-driven, near-decadal oscillation for at least 70 years. The historical oscillation (~13y) is remarkably consistent among small seepage lakes, groundwater tables and the two largest Laurentian Great Lakes despite substantial differences in hydrology. Hydrologic analyses indicate that the oscillation has been governed primarily by changes in the net atmospheric flux of water (P-E) and stage-dependent outflow. The oscillation is hypothetically connected to large-scale atmospheric circulation patterns originating in the mid-latitude North Pacific that support the flux of moisture into the region from the Gulf of Mexico. Recent data indicate an apparent change in the historical oscillation characterized by a ~12y downward trend beginning in 1998. Record low water levels region-wide may mark the onset of a new hydroclimatic regime.

A palaeoenvironmental reconstruction of c. 2 million year old Oldowan archaeological occurrences on the Homa Peninsula, southwestern Kenya: a multiproxy approach

Science.gov (United States)

Vincent, Thomas; Whitfield, Elizabeth; Kirby, Jason; Hunt, Christopher; Bishop, Laura; Plummer, Thomas; Ditchfield, Peter

2016-04-01

The Homa Peninsula, situated on the Winam Gulf of Lake Victoria, has yielded traces of hominin activity going back to at least ˜2ma BP. The best known site on the peninsula, Kanjera South, boasts large stone artefact and zooarchaeological assemblages preserved in three beds (from oldest to youngest: KS-1 to KS-3). Previous studies have used field sedimentological analyses, as well as stable isotope analysis of pedogenic carbonates to better understand the depositional and environmental contexts of hominin activities. These suggest that sediments were deposited in alluvial and lake marginal environments on a grassy plain, between wooded slopes and a permanent water body. The aim of this study is to refine previous palaeoenvironmental reconstructions of Kanjera South with the aid of particle size analysis, whilst also offering insights into the palaeoenvironment of other archaeological sites on the Homa Peninsula through a multiproxy approach. The project aims to include analyses of particle size, stable-isotopes, pollen and siliceous microfossils (phytoliths, diatoms and sponge spicules). Preliminary results of particle size and phytolith analyses have refined interpretations of the depositional environment at Kanjera South for beds KS1-3. Poor sorting, a bimodal distribution and sand/silty-sand grade material characterise the sediments. The characteristics suggest rapid deposition and/or a variable energy regime. A varying flow regime in relatively unconfined ephemeral channels might explain the transportation and deposition of sediments. Fluvial reworking of aeolian sediments, most likely during unconfined flood events may also have occurred. Phytoliths from the same beds showed grassland indicating Pooideae, as well as some Bambusoideae and woodland indicating phytoliths; this supports previous work.

Diel vertical migration of major fish-species in Lake Victoria, East Africa

NARCIS (Netherlands)

Goudswaard, P.C.; Wanink, J.H.; Witte, F.; Katunzi, E.F.B.; Berger, M.R.; Postma, D.J.

2004-01-01

Understanding of migration patterns is essential in the interpretation of hydro-acoustic stock assessment data of partly demersal partly pelagic fish stocks. In this paper we provide this kind of information for some species that were common in the Mwanza Gulf of Lake Victoria in the 1980s, before

Diel vertical migration of major fish-species in Lake Victoria, East Africa.

NARCIS (Netherlands)

Goudswaard, KPC; Wanink, JH; Witte, F; Katunzi, EFB; Berger, MR; Postma, DJ

2004-01-01

Understanding of migration patterns is essential in the interpretation of hydro-acoustic stock assessment data of partly demersal partly pelagic fish stocks. In this paper we provide this kind of information for some species that were common in the Mwanza Gulf of Lake Victoria in the 1980s, before

Sediment deposition and sources into a Mississippi River floodplain lake; Catahoula Lake, Louisiana

Science.gov (United States)

Latuso, Karen D.; Keim, Richard F.; King, Sammy L.; Weindorf, David C.; DeLaune, Ronald D.

2017-01-01

Floodplain lakes are important wetlands on many lowland floodplains of the world but depressional floodplain lakes are rare in the Mississippi River Alluvial Valley. One of the largest is Catahoula Lake, which has existed with seasonally fluctuating water levels for several thousand years but is now in an increasingly hydrologically altered floodplain. Woody vegetation has been encroaching into the lake bed and the rate of this expansion has increased since major human hydrologic modifications, such as channelization, levee construction, and dredging for improvement of navigation, but it remains unknown what role those modifications may have played in altering lake sedimentation processes. Profiles of thirteen 137Cs sediment cores indicate sedimentation has been about 0.26 cm y− 1 over the past 60 years and has been near this rate since land use changes began about 200 years ago (210Pb, and 14C in Tedford, 2009). Carbon sequestration was low (10.4 g m− 2 y− 1), likely because annual drying promotes mineralization and export. Elemental composition (high Zr and Ti and low Ca and K) and low pH of recent (sediments suggest Gulf Coastal Plain origin, but below the recent sediment deposits, 51% of sediment profiles showed influence of Mississippi River alluvium, rich in base cations such as K+, Ca2 +, and Mg2 +. The recent shift to dominance of Coastal Plain sediments on the lake-bed surface suggests hydrologic modification has disconnected the lake from sediment-bearing flows from the Mississippi River. Compared to its condition prior to hydrologic alterations that intensified in the 1930s, Catahoula Lake is about 15 cm shallower and surficial sediments are more acidic. Although these results are not sufficient to attribute ecological changes directly to sedimentological changes, it is likely the altered sedimentary and hydrologic environment is contributing to the increased dominance of woody vegetation.

Great Lakes

Science.gov (United States)

Edsall, Thomas A.; Mac, Michael J.; Opler, Paul A.; Puckett Haecker, Catherine E.; Doran, Peter D.

1998-01-01

The Great Lakes region, as defined here, includes the Great Lakes and their drainage basins in Minnesota, Wisconsin, Illinois, Indiana, Ohio, Pennsylvania, and New York. The region also includes the portions of Minnesota, Wisconsin, and the 21 northernmost counties of Illinois that lie in the Mississippi River drainage basin, outside the floodplain of the river. The region spans about 9º of latitude and 20º of longitude and lies roughly halfway between the equator and the North Pole in a lowland corridor that extends from the Gulf of Mexico to the Arctic Ocean.The Great Lakes are the most prominent natural feature of the region (Fig. 1). They have a combined surface area of about 245,000 square kilometers and are among the largest, deepest lakes in the world. They are the largest single aggregation of fresh water on the planet (excluding the polar ice caps) and are the only glacial feature on Earth visible from the surface of the moon (The Nature Conservancy 1994a).The Great Lakes moderate the region’s climate, which presently ranges from subarctic in the north to humid continental warm in the south (Fig. 2), reflecting the movement of major weather masses from the north and south (U.S. Department of the Interior 1970; Eichenlaub 1979). The lakes act as heat sinks in summer and heat sources in winter and are major reservoirs that help humidify much of the region. They also create local precipitation belts in areas where air masses are pushed across the lakes by prevailing winds, pick up moisture from the lake surface, and then drop that moisture over land on the other side of the lake. The mean annual frost-free period—a general measure of the growing-season length for plants and some cold-blooded animals—varies from 60 days at higher elevations in the north to 160 days in lakeshore areas in the south. The climate influences the general distribution of wild plants and animals in the region and also influences the activities and distribution of the human

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

Energy Technology Data Exchange (ETDEWEB)

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

2016-01-15

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

Snow bands over the Gulf of Finland in wintertime

Directory of Open Access Journals (Sweden)

Jordi Mazon

2015-01-01

Full Text Available Large shore-parallel, quasi-stationary snow bands are occasionally observed over the Gulf of Finland during wintertime when the sea is not frozen. On the basis of Weather Research and Forecasting mesoscale model experiments and radar observations of snow bands formed in January 2006 and February 2012, we show that their dynamics share common characteristics: (1 the sea gulf that produces the known lake effect, (2 cold easterly large-scale flow along the gulf and (3 a cold local flow from the two near and opposite coastlines of Estonia and Finland in the form of two land-breeze cells which collide offshore. The associated fronts, which have strong rising motions, are maintained by the convergence of the land-breeze cells. In addition to these factors, the concave shape of the coast in the eastern part of the Gulf of Finland promotes offshore convergence and the formation of several secondary bands of precipitation that are adjacent to the eastern part of the main band. When the easterlies turn to southerlies, horizontal convective rolls appear over the sea. The Estonian land breeze is enhanced while the cold air remains stagnant inland over the Finnish coast, acting as an orographic barrier lifting the marine air mass upwards. Consequently, a line of convective precipitation composed of several cells is formed along the Finnish coast. In both events, the simulations also show two low-level jets generated by the combined effects of the land-breeze cells and baroclinicity over the coast of Finland and Estonia.

A mathematical model for lake ontogeny in terms of filling with sediments and macrophyte vegetation

International Nuclear Information System (INIS)

Brydsten, Lars

2004-05-01

A mathematical model for simulation of lake basin filling processes in areas with positive shore displacement was constructed. The model was calibrated using sediment and catchments data from eight existing lake basins situated in the northern coastal area of the province of Uppland, Sweden. The lake basin filling processes were separated into three phases: basin filling with wave-washed material (silt, silty sand or sand), filling with fine-grained material during the shallow gulf and lake stages, respectively, and filling with vegetation during the lake stage. The basin filling rates for wave-washed material were generally low but varied considerably both between and within lakes. The mean basin filling rate of wave-washed material was 4.1%. The volume of inorganic sediments produced, and basin filling rates during the shallow gulf and lake phases were determined for all the eight lakes. The relationship between basin filling rate and parameters describing the catchments, the former postglacial basins and the lakes, respectively, was determined using multiple regression analysis. The basin filling rate with inorganic sediments was best described by parameters related to former postglacial basin morphometry and current lake morphometry, e.g. basin volume, lake volume, and lake area. The goodness of fit turned out to be 0.99 for a simple regression with basin volume as the sole independent variable. The basin filling with vegetation (Phragmites australis followed by Sphagnum spp.) was treated as a 2-dimensional process. A dataset with 84 bogs was selected from a digital soil map. The ages of the bogs were calculated using a digital elevation map and an equation for shore displacement. The choke-up rate was then calculated by dividing the area of the bogs with their age. A strong exponential relationship exists between areas of the bogs and choke-up rat, and this relationship was then used in the model. The resulting model starts by filling the former coastal basin

A mathematical model for lake ontogeny in terms of filling with sediments and macrophyte vegetation

Energy Technology Data Exchange (ETDEWEB)

Brydsten, Lars [Umeaa Univ. (Sweden). Dept. of Biology and Environmental Science

2004-05-01

A mathematical model for simulation of lake basin filling processes in areas with positive shore displacement was constructed. The model was calibrated using sediment and catchments data from eight existing lake basins situated in the northern coastal area of the province of Uppland, Sweden. The lake basin filling processes were separated into three phases: basin filling with wave-washed material (silt, silty sand or sand), filling with fine-grained material during the shallow gulf and lake stages, respectively, and filling with vegetation during the lake stage. The basin filling rates for wave-washed material were generally low but varied considerably both between and within lakes. The mean basin filling rate of wave-washed material was 4.1%. The volume of inorganic sediments produced, and basin filling rates during the shallow gulf and lake phases were determined for all the eight lakes. The relationship between basin filling rate and parameters describing the catchments, the former postglacial basins and the lakes, respectively, was determined using multiple regression analysis. The basin filling rate with inorganic sediments was best described by parameters related to former postglacial basin morphometry and current lake morphometry, e.g. basin volume, lake volume, and lake area. The goodness of fit turned out to be 0.99 for a simple regression with basin volume as the sole independent variable. The basin filling with vegetation (Phragmites australis followed by Sphagnum spp.) was treated as a 2-dimensional process. A dataset with 84 bogs was selected from a digital soil map. The ages of the bogs were calculated using a digital elevation map and an equation for shore displacement. The choke-up rate was then calculated by dividing the area of the bogs with their age. A strong exponential relationship exists between areas of the bogs and choke-up rat, and this relationship was then used in the model. The resulting model starts by filling the former coastal basin

Prevalence of Gulf war veterans who believe they have Gulf war syndrome: questionnaire study

Science.gov (United States)

Chalder, T; Hotopf, M; Unwin, C; Hull, L; Ismail, K; David, A; Wessely, S

2001-01-01

Objectives To determine how many veterans in a random sample of British veterans who served in the Gulf war believe they have “Gulf war syndrome,” to examine factors associated with the presence of this belief, and to compare the health status of those who believe they have Gulf war syndrome with those who do not. Design Questionnaire study asking British Gulf war veterans whether they believe they have Gulf war syndrome and about symptoms, fatigue, psychological distress, post-traumatic stress, physical functioning, and their perception of health. Participants 2961 respondents to questionnaires sent out to a random sample of 4250 Gulf war veterans (69.7%). Main outcome measure The proportion of veterans who believe they have Gulf war syndrome. Results Overall, 17.3% (95% confidence interval 15.9 to 18.7) of the respondents believed they had Gulf war syndrome. The belief was associated with the veteran having poor health, not serving in the army when responding to the questionnaire, and having received a high number of vaccinations before deployment to the Gulf. The strongest association was knowing another person who also thought they had Gulf war syndrome. Conclusions Substantial numbers of British Gulf war veterans believe they have Gulf war syndrome, which is associated with psychological distress, a high number of symptoms, and some reduction in activity levels. A combination of biological, psychological, and sociological factors are associated with the belief, and these factors should be addressed in clinical practice. What is already known on this topicThe term Gulf war syndrome has been used to describe illnesses and symptoms experienced by veterans of the 1991 Gulf warConcerns exist over the validity of Gulf war syndrome as a unique entityWhat this study adds17% of Gulf war veterans believe they have Gulf war syndromeHolding the belief is associated with worse health outcomesKnowing someone else who believes they have Gulf war syndrome and receiving

Palaeoenvironment and shoreline displacement on Suursaari Island, the Gulf of Finland

Directory of Open Access Journals (Sweden)

Atko Heinsalu

2000-01-01

Full Text Available The island of Suursaari in the middle of the Gulf of Finland is exceptionally high (175 m a.s.l.. Sediment profiles from one mire and three lakes were investigated using diatom and pollen analysis, radiocarbon dating and levelling of the elevations of ancient shorelines. The pollen stratigraphy of the Lounatkorkiasuo Mire sediment suggests a sedimentary record dating from the late Allerød.The development of late-glacial vegetation went through the same phases as in southern Finland, however these are probably somewhat earlier on the island of Suursaari. There are differences in the Holocene vegetation history of the higher and lower areas of the island. Lake Ruokalahenjärvi was isolated around 10 000 BP during the initial phase of the Yoldia Sea and the diatom assemblage indicates that at that time brackish-water flow had not penetrated into the Gulfof Finland. Diatoms from the isolation sediments of Lake Liivalahenjärvi and Lake Veteljärvi indicate a freshwater environment for the Yoldia Sea final phase at 9500–9600 BP. Levelling of coastal formations on Suursaari Island reveals that the Late Weichselian and early Holocene ancient shorelines are 5–15 m higher than expected from the isobase data for similar land uplift areas on the mainland.The anomalous shoreline levels on Suursaari Island may be explained byirregular land uplift. By the time of the Litorina Sea differences in shoreline altitudes had disappeared.

Collapse and reorganization of a food web of Mwanza Gulf, Lake Victoria

NARCIS (Netherlands)

Downing, A.S.; Van Nes, E.H.; Janse, J.H.; Witte, F.; Cornelissen, I.J.M.; Scheffer, M.; Mooij, W.M.

2012-01-01

Lake Victoria (in East Africa) is the world's second largest fresh-water system. Over the past century the ecosystem has undergone drastic changes. Some 30 years after the introduction of Nile perch and tilapia in the 1950s, the highly diverse community of native haplochromines collapsed, leaving a

RADARSAT SAR data assessment of oil lakes in the Greater Burgan Oil Field, Kuwait

International Nuclear Information System (INIS)

Kwarteng, A. Y.; Al-Ajmi, D.; Singhroy, V.; Saint-Jean, R.

1997-01-01

RADARSAT images recorded in different beam modes were processed and used to assess the oil lakes in the Burgan oil field in Kuwait created by the fire setting of oil wells by the retreating Iraqi forces in the 1990-1991 Gulf War. The images were geometrically registered to each other and used as input to a change detection program. The main interest was to map and differentiate between the oil lakes, tarmats, vegetation, buried oil lakes, and also to evaluate the usefulness of RADARSAT's beam modes in characterizing such features. Results of the RADARSAT imagery analysis were compared to similar studies using optical and SIR-C/X-SAR data. Initially, there have approximately 300 oil lakes covering an area of about 49 sq km. Twenty-one million barrels of oil were recovered and exported; about one million barrels of unrecoverable oil was left in the oil fields. Since then most of the oil has evaporated, dried up to form tarmats, or has been covered by a veneer of sand and is no longer visible on the surface

2015 Gulf Guardian Awards

Science.gov (United States)

The Gulf of Mexico Program Partnership developed the Gulf Guardian awards as a way to recognize and honor the businesses, community groups, individuals, and agencies that are taking positive steps to keep the Gulf healthy, beautiful and productive.

Hydro- and morphodynamic tsunami simulations for the Ambrakian Gulf (Greece) and comparison with geoscientific field traces

Science.gov (United States)

Röbke, B. R.; Schüttrumpf, H.; Vött, A.

2018-04-01

In order to derive local tsunami risks for a particular coast, hydro- and morphodynamic numerical models that are calibrated and compared with sedimentary field data of past tsunami impacts have proven very effective. While this approach has widely been used with regard to recent tsunami events, comparable investigations into pre-/historical tsunami impacts hardly exist, which is the objective of this study focusing on the Ambrakian Gulf in northwestern Greece. The Ambrakian Gulf is located in the most active seismotectonic and by this most tsunamigenic area of the Mediterranean. Accordingly, palaeotsunami field studies have revealed repeated tsunami impacts on the gulf during the past 8000 yr. The current study analyses 151 vibracores of the Ambrakian Gulf coast in order to evaluate tsunami signals in the sedimentary record. Based on a hydro- and morphodynamic numerical model of the study area, various tsunami waves are simulated with the aim of finding scenarios that compare favourably with tsunami deposits detected in the field. Both, field data and simulation results suggest a decreasing tsunami influence from the western to the eastern Ambrakian Gulf. Various scenarios are needed to explain tsunami deposits in different parts of the gulf. Whereas shorter period tsunami waves (T = 30 min) from the south and west compare favourably with field data in the western gulf, longer period waves (T = 80 min) from a western direction show the best agreement with tsunami sediments detected in southwestern Aktio Headland and in the more central parts of the Ambrakian Gulf including Lake Voulkaria. Tsunamis from the southwest generally do not accord with field traces. Besides the spatial sediment distribution, the numerical model accurately reflects the sedimentary composition of the detected event deposits and reproduces a number of essential features typical of tsunamites, which were also observed in the field. Such include fining- and thinning-landward and the marine

Wetlands of the Gulf Coast

Science.gov (United States)

2001-01-01

This set of images from the Multi-angle Imaging SpectroRadiometer highlights coastal areas of four states along the Gulf of Mexico: Louisiana, Mississippi, Alabama and part of the Florida panhandle. The images were acquired on October 15, 2001 (Terra orbit 9718)and represent an area of 345 kilometers x 315 kilometers.The two smaller images on the right are (top) a natural color view comprised of red, green, and blue band data from MISR's nadir(vertical-viewing) camera, and (bottom) a false-color view comprised of near-infrared, red, and blue band data from the same camera. The predominantly red color of the false-color image is due to the presence of vegetation, which is bright at near-infrared wavelengths. Cities appear as grey patches, with New Orleans visible at the southern edge of Lake Pontchartrain, along the left-hand side of the images. The Lake Pontchartrain Bridge runs approximately north-south across the middle of the lake. The distinctive shape of the Mississippi River Delta can be seen to the southeast of New Orleans. Other coastal cities are visible east of the Mississippi, including Biloxi, Mobile and Pensacola.The large image is similar to the true-color nadir view, except that red band data from the 60-degree backward-looking camera has been substituted into the red channel; the blue and green data from the nadir camera have been preserved. In this visualization, green hues appear somewhat subdued, and a number of areas with a reddish color are present, particularly near the mouths of the Mississippi, Pascagoula, Mobile-Tensaw, and Escambia Rivers. Here, the red color is highlighting differences in surface texture. This combination of angular and spectral information differentiates areas with aquatic vegetation associated with poorly drained bottom lands, marshes, and/or estuaries from the surrounding surface vegetation. These wetland regions are not as well differentiated in the conventional nadir views.Variations in ocean color are apparent in

Hurricane shuts down gulf activity

International Nuclear Information System (INIS)

Koen, A.D.

1992-01-01

This paper reports that producers in the Gulf of Mexico and plant operators in South Louisiana last week were checking for damage wrought by Hurricane Andrew. In its wake Andrew left evacuated rigs and platforms in the gulf and shuttered plants across a wide swath of the Gulf Coast. Operations were beginning to return to normal late last week. Not all gulf operators, especially in the central gulf, expected to return to offshore facilities. And even producers able to book helicopters did not expect to be able to fully assess damage to all offshore installations before the weekend. MMS officials in Washington estimated that 37,500 offshore workers were evacuated from 700 oil and gas installations on the gulf's Outer Continental Shelf. Gulf oil and gas wells account for about 800,000 b/d of oil and one fourth of total U.S. gas production. MMS was awaiting an assessment of hurricane damage before estimating how soon and how much gulf oil and gas production would be restored

Vascular flora of saline lakes in the southern high plains of Texas and eastern New Mexico

Science.gov (United States)

Rosen, David J.; Conway, Warren C.; Haukos, David A.; Caskey, Amber D.

2013-01-01

Saline lakes and freshwater playas form the principal surface hydrological feature of the High Plains of the Southern Great Plains. Saline lakes number less than 50 and historically functioned as discharge wetlands with relatively consistent water availability due to the presence of one or more springs. Currently, less than ten saline lakes contain functional springs. A survey of vascular plants at six saline lakes in the Southern High Plains of northwest Texas and one in eastern New Mexico during May and September 2009 resulted in a checklist of 49 species representing 16 families and 40 genera. The four families with the most species were Asteraceae (12), Amaranthaceae (8), Cyperaceae (5), and Poaceae (12). Non-native species (Bromus catharticus, Poa compressa, Polypogon monspeliensis, Sonchus oleraceus, Kochia scoparia, and Tamarix ramosissima) accounted for 10% of the total species recorded. Whereas nearly 350 species of vascular plants have been identified in playas in the Southern High Plains, saline lakes contain a fraction of this species richness. The Southern High Plains saline lake flora is regionally unique, containing taxa not found in playas, with species composition that is more similar to temperate desert wetlands of the Intermountain Region and Gulf Coastal Plain of North America.

76 FR 54375 - Safety Zone; Thunder on the Gulf, Gulf of Mexico, Orange Beach, AL

Science.gov (United States)

2011-09-01

...-AA00 Safety Zone; Thunder on the Gulf, Gulf of Mexico, Orange Beach, AL AGENCY: Coast Guard, DHS... portion of the Gulf of Mexico for the waters off Orange Beach, Alabama. This action is necessary for the... conduct a high speed boat race on the Gulf of Mexico, south of Orange Beach, Alabama to occur from October...

No evidence for altered cellular immune functions in personnel deployed in the Persian Gulf during and after the Gulf War--The Danish Gulf War study

DEFF Research Database (Denmark)

Bregenholt, S; Ishøy, T; Skovgaard, L T

2001-01-01

Veterans who have participated in the Gulf War suffer from a number of symptoms, collectively referred to as the Gulf War Syndrome. It has been hypothesized that a change in the systemic cytokine balance or other changes in immunological parameters could be responsible for some of the symptoms. We...... analyzed the peripheral blood natural killer (NK) cell activity of 686 Gulf War personnel who had been present in the Persian Gulf area during and immediately after the Gulf War as well as 231 gender and age-matched controls. The test material included individual samples of frozen peripheral blood...

2015 Gulf Guardian Award Winners

Science.gov (United States)

The Gulf of Mexico Program Partnership developed the Gulf Guardian awards as a way to recognize and honor the businesses, community groups, individuals, and agencies that are taking positive steps to keep the Gulf healthy, beautiful and productive.

2017 Gulf Guardian Award Winners

Science.gov (United States)

The Gulf of Mexico Program Partnership developed the Gulf Guardian awards as a way to recognize and honor the businesses, community groups, individuals, and agencies that are taking positive steps to keep the Gulf healthy, beautiful and productive.

A Late Holocene Record of Human Impact in the Tropical Lowlands of the Mexican Gulf Coast: Lago Verde.

Science.gov (United States)

Socorro, L.; Sosa, S.; Caballero, M.; Rodriguez, A.; Ortega, B.

2005-05-01

Lago Verde is a maar lake (18 36 43 N; 95 20 52 W) located on the Gulf Coast of Mexico in "Los Tuxtlas" region. The area was cover by tropical rain forest and is part of the core area of the earliest Mesoamerican cultures. A 6 m sediment core was obtained in order to document vegetation and lake level history of this area. Lago Verde is a shallow, eutrophic lake (max. 4 m), the natural vegetation has been removed and grasslands with some tropical trees such Bursera grows around the lake. According with the radiocarbon chronology the sequence covers the last 2500 yr BP. At the base of the sequence low abundance of tropical trees is record, with intermediate lake levels. A sudden change in the pollen stratigraphy occurs at ca. 2000 yr BP, with important presence of Poaceae, Ambrosia and Cheno.-Am. along with Zea mays indicating human activity in the area. This is associated with a change in limnological conditions, recording turbid, shallow environments. This pollen signals correlates with dry phases in Yucatan, suggesting that this dry climatic signal probably had effect on an ample area of Mexico. However, at 1200 yr BP, no more Zea mays pollen is recovered suggesting the abandonment of the area. Lake levels recover as well as the tropical forest. The last 150 yr BP is characterized by the reduction in the pollen of tropical forest trees, presence of Zea mays, increased erosion rates, turbidity and eutrophication in the lake, all related to deforestation.

78 FR 14983 - Fisheries of the Gulf of Mexico; Gulf of Mexico Fishery Management Council; Public Meeting

Science.gov (United States)

2013-03-08

... the Gulf of Mexico; Gulf of Mexico Fishery Management Council; Public Meeting AGENCY: National Marine... of Gulf of Mexico Fishery Management Council Spanish Mackerel and Cobia Stock Assessment Review Workshop. SUMMARY: Independent peer review of Gulf of Mexico Spanish Mackerel and Cobia stocks will be...

New paleoreconstruction of transgressive stages in the northern part of Lake Ladoga, NW Russia.

Science.gov (United States)

Terekhov, Anton; Sapelko, Tatyana

2016-04-01

Lake Ladoga is one of the largest lakes in the world and the largest in Europe. The watershed of lake Ladoga covers the North-Western part of European Russia and the Eastern Finland. Lake basin is on the border between the Baltic shield and the East European Platform. The most consistent paleoreconstructions of Lake Ladoga history are based on bottom sediments of smaller lakes, which used to be a part of Ladoga in the past. The stages of Ladoga evolution are directly connected with the history of the Baltic Ice Lake (BIL) and of the Ancylus Lake. Water level of these lakes was significant higher than nowadays level. Lake Ladoga in its present limits used to be an Eastern gulf of BIL and Ancylus Lake. The preceding paleoreconstructions of Ladoga water level oscillations were undertaken by G. de Geer, J. Ailio, E. Hyyppä, K. Markov, D. Kvasov, D. Malakhovskiy, M. Ekman, G. Lak, N. Davydova, M. Saarnisto, D. Subetto and others. The new data on multivariate analysis of bottom sediments of lakes which used to belong to Ladoga, collected in the last few years, allows to create several maps of Ladoga transgressive stages in Late Glacial period and post-glacial time. A series of maps showing the extent of Ladoga transgression was created based on lake sediments multivariate analysis and a GIS-modeling using the digital elevation data with an accuracy of several meters and an open-source software (QGIS and SAGA). Due to post-glacial rebound of the lake watershed territory, GIS-modeling should comprise the extent of the glacioisostatic uplift, so the chart of a present-day uplift velocity for Fennoscandia of Ekman and Mäkinen was used. The new digital elevation models were calculated for several moments in the past, corresponding to the most probable dates of smaller lakes isolation from Lake Ladoga. Then, the basin of Ladoga was "filled" with water into GIS program to the levels sufficient for the smaller lakes to join and to split-off. The modern coastlines of Ladoga and

77 FR 56168 - Reef Fish Fishery of the Gulf of Mexico; Gulf of Mexico Individual Fishing Quota Programs

Science.gov (United States)

2012-09-12

.... 090206140-91081-03] RIN 0648-XC227 Reef Fish Fishery of the Gulf of Mexico; Gulf of Mexico Individual... red snapper and grouper/tilefish components of the reef fish fishery in the Gulf of Mexico (Gulf), the... INFORMATION: The reef fish fishery of the Gulf of Mexico is managed under the Fishery Management Plan for Reef...

75 FR 54445 - Proposed Information Collection (Follow-Up Study of a National Cohort of Gulf War and Gulf Era...

Science.gov (United States)

2010-09-07

... Collection (Follow-Up Study of a National Cohort of Gulf War and Gulf Era Veterans) Activity: Comment Request... assist in VA's efforts to address the health concerns and problems of Gulf War Veterans. DATES: Written... of Gulf War and Gulf Era Veterans, VA Form 10-0488, and Consent Form for Release of Medical Records...

76 FR 64248 - Gulf of Mexico Reef Fish Fishery; Closure of the 2011 Gulf of Mexico Commercial Sector for...

Science.gov (United States)

2011-10-18

.... 040205043-4043-01] RIN 0648-XA766 Gulf of Mexico Reef Fish Fishery; Closure of the 2011 Gulf of Mexico... the commercial sector for greater amberjack in the exclusive economic zone (EEZ) of the Gulf of Mexico... Reef Fish Resources of the Gulf of Mexico (FMP). The FMP was prepared by the Gulf of Mexico Fishery...

75 FR 70365 - Agency Information Collection (Follow-Up Study of a National Cohort of Gulf War and Gulf Era...

Science.gov (United States)

2010-11-17

... (Follow-Up Study of a National Cohort of Gulf War and Gulf Era Veterans) Activity Under OMB Review AGENCY...).'' SUPPLEMENTARY INFORMATION: Titles: Follow-Up Study of a National Cohort of Gulf War and Gulf Era Veterans, VA..., will help VA to assess the health of Gulf War veterans who were exposed to a variety of environmental...

The Lake Charles CCS Project

Energy Technology Data Exchange (ETDEWEB)

Doug Cathro

2010-06-30

The Lake Charles CCS Project is a large-scale industrial carbon capture and sequestration (CCS) project which will demonstrate advanced technologies that capture and sequester carbon dioxide (CO{sub 2}) emissions from industrial sources into underground formations. Specifically the Lake Charles CCS Project will accelerate commercialization of large-scale CO{sub 2} storage from industrial sources by leveraging synergy between a proposed petroleum coke to chemicals plant (the LCC Gasification Project) and the largest integrated anthropogenic CO{sub 2} capture, transport, and monitored sequestration program in the U.S. Gulf Coast Region. The Lake Charles CCS Project will promote the expansion of EOR in Texas and Louisiana and supply greater energy security by expanding domestic energy supplies. The capture, compression, pipeline, injection, and monitoring infrastructure will continue to sequester CO{sub 2} for many years after the completion of the term of the DOE agreement. The objectives of this project are expected to be fulfilled by working through two distinct phases. The overall objective of Phase 1 was to develop a fully definitive project basis for a competitive Renewal Application process to proceed into Phase 2 - Design, Construction and Operations. Phase 1 includes the studies attached hereto that will establish: the engineering design basis for the capture, compression and transportation of CO{sub 2} from the LCC Gasification Project, and the criteria and specifications for a monitoring, verification and accounting (MVA) plan at the Hastings oil field in Texas. The overall objective of Phase 2, provided a successful competitive down-selection, is to execute design, construction and operations of three capital projects: (1) the CO{sub 2} capture and compression equipment, (2) a Connector Pipeline from the LLC Gasification Project to the Green Pipeline owned by Denbury and an affiliate of Denbury, and (3) a comprehensive MVA system at the Hastings oil field.

LIMNOLOGY, LAKE BASINS, LAKE WATERS

Directory of Open Access Journals (Sweden)

Petre GÂŞTESCU

2009-06-01

Full Text Available Limnology is a border discipline between geography, hydrology and biology, and is also closely connected with other sciences, from it borrows research methods. Physical limnology (the geography of lakes, studies lake biotopes, and biological limnology (the biology of lakes, studies lake biocoenoses. The father of limnology is the Swiss scientist F.A. Forel, the author of a three-volume entitled Le Leman: monographie limnologique (1892-1904, which focuses on the geology physics, chemistry and biology of lakes. He was also author of the first textbook of limnology, Handbuch der Seenkunde: allgemeine Limnologie,(1901. Since both the lake biotope and its biohydrocoenosis make up a single whole, the lake and lakes, respectively, represent the most typical systems in nature. They could be called limnosystems (lacustrine ecosystems, a microcosm in itself, as the American biologist St.A. Forbes put it (1887.

Simulation of Lake Victoria Circulation Patterns Using the Regional Ocean Modeling System (ROMS.

Directory of Open Access Journals (Sweden)

Chrispine Nyamweya

Full Text Available Lake Victoria provides important ecosystem services including transport, water for domestic and industrial uses and fisheries to about 33 million inhabitants in three East African countries. The lake plays an important role in modulating regional climate. Its thermodynamics and hydrodynamics are also influenced by prevailing climatic and weather conditions on diel, seasonal and annual scales. However, information on water temperature and circulation in the lake is limited in space and time. We use a Regional Oceanographic Model System (ROMS to simulate these processes from 1st January 2000 to 31st December 2014. The model is based on real bathymetry, river runoff and atmospheric forcing data using the bulk flux algorithm. Simulations show that the water column exhibits annual cycles of thermo-stratification (September-May and mixing (June-August. Surface water currents take different patterns ranging from a lake-wide northward flow to gyres that vary in size and number. An under flow exists that leads to the formation of upwelling and downwelling regions. Current velocities are highest at the center of the lake and on the western inshore waters indicating enhanced water circulation in those areas. However, there is little exchange of water between the major gulfs (especially Nyanza and the open lake, a factor that could be responsible for the different water quality reported in those regions. Findings of the present study enhance understanding of the physical processes (temperature and currents that have an effect on diel, seasonal, and annual variations in stratification, vertical mixing, inshore-offshore exchanges and fluxes of nutrients that ultimately influence the biotic distribution and trophic structure. For instance information on areas/timing of upwelling and vertical mixing obtained from this study will help predict locations/seasons of high primary production and ultimately fisheries productivity in Lake Victoria.

Simulation of Lake Victoria Circulation Patterns Using the Regional Ocean Modeling System (ROMS).

Science.gov (United States)

Nyamweya, Chrispine; Desjardins, Christopher; Sigurdsson, Sven; Tomasson, Tumi; Taabu-Munyaho, Anthony; Sitoki, Lewis; Stefansson, Gunnar

2016-01-01

Lake Victoria provides important ecosystem services including transport, water for domestic and industrial uses and fisheries to about 33 million inhabitants in three East African countries. The lake plays an important role in modulating regional climate. Its thermodynamics and hydrodynamics are also influenced by prevailing climatic and weather conditions on diel, seasonal and annual scales. However, information on water temperature and circulation in the lake is limited in space and time. We use a Regional Oceanographic Model System (ROMS) to simulate these processes from 1st January 2000 to 31st December 2014. The model is based on real bathymetry, river runoff and atmospheric forcing data using the bulk flux algorithm. Simulations show that the water column exhibits annual cycles of thermo-stratification (September-May) and mixing (June-August). Surface water currents take different patterns ranging from a lake-wide northward flow to gyres that vary in size and number. An under flow exists that leads to the formation of upwelling and downwelling regions. Current velocities are highest at the center of the lake and on the western inshore waters indicating enhanced water circulation in those areas. However, there is little exchange of water between the major gulfs (especially Nyanza) and the open lake, a factor that could be responsible for the different water quality reported in those regions. Findings of the present study enhance understanding of the physical processes (temperature and currents) that have an effect on diel, seasonal, and annual variations in stratification, vertical mixing, inshore-offshore exchanges and fluxes of nutrients that ultimately influence the biotic distribution and trophic structure. For instance information on areas/timing of upwelling and vertical mixing obtained from this study will help predict locations/seasons of high primary production and ultimately fisheries productivity in Lake Victoria.

Tides and seiches in gulfs

International Nuclear Information System (INIS)

Pierini, S.

1981-01-01

In this paper Garrett's theory of tides in gulfs is extended so that its formalism includes the free oscillations (seiches) of the gulf. The elevation of the free surface zeta and the velocity field u are obtained in a rectangular, one-dimensional gulf opening into an infinite ocean. An application of the results to the Adriatic sea can explain qualitatively the long life of the uninodal seiche of that basin. (author)

75 FR 54965 - Proposed Information Collection (Follow-Up Study of a National Cohort of Gulf War and Gulf Era...

Science.gov (United States)

2010-09-09

... Collection (Follow-Up Study of a National Cohort of Gulf War and Gulf Era Veterans) Activity: Comment Request... needed to assist in VA's efforts to address the health concerns and problems of Gulf War Veterans. DATES... use of other forms of information technology. Titles: Follow-Up Study of a National Cohort of Gulf War...

Influence of Subtropical Jetstream on Arabian Gulf Precipitation

Science.gov (United States)

Sandeep, S.; Pauluis, O.; Ravindran, A. M.; TP, S.

2017-12-01

The Arabian Gulf and surrounding regions are predominantly arid. However, this region hosts a large population due to the intense economic activity that is centered on the exploration of natural resources in and around the Arabian Gulf. Thus, few precipitation events that occur during boreal winter are important for society and ecology of this region. The mechanisms of winter precipitation over the Gulf are not well understood, partly due to a lack of long term meteorological observation. Here we explore the dynamics of Arabian Gulf winter precipitation events using available observations and a high resolution atmospheric model simulation. Our analyses show that the northern Gulf receives about six times more precipitation than the southern Gulf. Often, the southern Gulf precipitation forms as a result of downstream development of northern Gulf disturbance. The southward movement of northern Gulf disturbances is influenced by the location of subtropical jet. The probability of a northern Gulf precipitating weather system to move south is higher when the subtropical jet is located equatorward of 30°N. The equatorward position of jet favors the penetration of mid-latitude weather systems over the Arabian Peninsula, which in turn pushes the Arabian anticyclone eastward and triggers moisture transport from the Arabian Sea that is essential for southern Gulf precipitation events.

Gulf operations still recovering

International Nuclear Information System (INIS)

Koen, A.D.

1992-01-01

This paper reports that reports of damage caused by Hurricane Andrew were leveling off last week at the U.S. Minerals Management Service as Gulf of Mexico operators pressed ahead with repairs. The hurricane struck South Florida Aug. 4, churned west into the gulf, then swung north and hit the South Louisiana coast Aug. 5. By the close of business Sept. 8 MMS had received damage reports covering 83 pipeline segments and 193 platforms and satellite installations. MMS last week estimated about 500 MMcfd of gas production had been restored in the gulf and 100,000-150,000 b/d of oil. Production still lost as a result of Andrew was estimated at 2-2.5 bcfd of gas and 90,000-120 b/d of oil. MMS estimates Gulf of Mexico wells before the storm were producing about 12.5-13 bcfd of gas and 750,000 b/d of oil

Temperature of the Gulf Stream

Science.gov (United States)

2002-01-01

The Gulf Stream is one of the strong ocean currents that carries warm water from the sunny tropics to higher latitudes. The current stretches from the Gulf of Mexico up the East Coast of the United States, departs from North America south of the Chesapeake Bay, and heads across the Atlantic to the British Isles. The water within the Gulf Stream moves at the stately pace of 4 miles per hour. Even though the current cools as the water travels thousands of miles, it remains strong enough to moderate the Northern European climate. The image above was derived from the infrared measurements of the Moderate-resolution Imaging Spectroradiometer (MODIS) on a nearly cloud-free day over the east coast of the United States. The coldest waters are shown as purple, with blue, green, yellow, and red representing progressively warmer water. Temperatures range from about 7 to 22 degrees Celsius. The core of the Gulf Stream is very apparent as the warmest water, dark red. It departs from the coast at Cape Hatteras, North Carolina. The cool, shelf water from the north entrains the warmer outflows from the Chesapeake and Delaware Bays. The north wall of the Gulf Stream reveals very complex structure associated with frontal instabilities that lead to exchanges between the Gulf Stream and inshore waters. Several clockwise-rotating warm core eddies are evident north of the core of the Gulf Stream, which enhance the exchange of heat and water between the coastal and deep ocean. Cold core eddies, which rotate counter clockwise, are seen south of the Gulf Stream. The one closest to Cape Hatteras is entraining very warm Gulf Stream waters on its northwest circumference. Near the coast, shallower waters have warmed due to solar heating, while the deeper waters offshore are markedly cooler (dark blue). MODIS made this observation on May 8, 2000, at 11:45 a.m. EDT. For more information, see the MODIS-Ocean web page. The sea surface temperature image was created at the University of Miami using

The rise and fall of water hyacinth in Lake Victoria and the Kagera River basin, 1989-2001

Science.gov (United States)

Albright, Thomas P.; Moorhouse, T.G.; McNabb, T.J.

2004-01-01

Water hyacinth (Eichhornia crassipes (Mart.) Solms) is an invasive aquatic macrophyte associated with major negative economic and ecological impacts to the Lake Victoria region since the plant's establishment in Uganda in the 1980s. Reliable estimates of water hyacinth distribution and extent are required to gauge the severity of the problem through time, relate water hyacinth abundance to environmental factors, identify areas requiring management action, and assess the efficacy of management actions. To provide such estimates and demonstrate the utility of remote sensing for this application, we processed and analyzed remotely sensed imagery to determine the distribution and extent of water hyacinth. Maps were produced and coverage was quantified using a hybrid unsupervised image classification approach with manual editing for each of the riparian countries of Kenya, Tanzania, and Uganda, as well as for numerous gulfs and bays. A similar procedure was carried out for selected lakes in the Rwanda-Tanzania borderlands lakes region in the Kagera River basin. Results confirm the severity of the water hyacinth infestation, especially in the northern parts of the lake. A maximum lake-wide extent of at least 17,374 ha was attained in 1998. Following this, a combination of factors, including conditions associated with the 1997 to 1998 El Nin??o and biocontrol with water hyacinth weevils, appear to have contributed to a major decline in water hyacinth in the most affected parts of the lake. Some lakes in the Kagera basin, such as Lake Mihindi, Rwanda, were severely infested in the late 1990s, but the level of infestation in most of these decreased markedly by the early 2000s.

Squalius namak, a new chub from Lake Namak basin in Iran (Teleostei: Cyprinidae).

Science.gov (United States)

Khaefi, Roozbehan; Esmaeili, Hamid Reza; Sayyadzadeh, Golnaz; Geiger, Matthias F; Freyhof, Jörg

2016-09-19

Squalius namak, new species, from the endorheic Lake Namak and Kavir basins in Iran, is distinguished from the species of the genus Squalius in the Persian Gulf and the southern Caspian Sea basins by having a wide and thick symphysial knob on the lower jaw, a convex posterior anal-fin margin, a bold, dark-grey or brown, roundish or crescent-shaped blotch at the posterior tip of each flank scale and orange caudal-, anal- and pelvic-fin rays in life. Squalius namak is also characterized by four fixed, diagnostic nucleotide substitutions in the mtDNA COI barcode region.

Thermohaline circulation in the Gulf of California

Science.gov (United States)

Bray, N. A.

1988-05-01

The Gulf of California, a narrow, semienclosed sea, is the only evaporative basin of the Pacific Ocean. As a result of evaporative forcing, salinities in the gulf are 1 to 2 ‰ higher than in the adjacent Pacific at the same latitude. This paper examines the thermohaline structure of the gulf and the means by which thermohaline exchange between the Pacific and the gulf occurs, over time scales of months to years. In addition to evaporative forcing, air-sea heat fluxes and momentum fluxes are important to thermohaline circulation in the gulf. From observations presented here, it appears that the gulf gains heat from the atmosphere on an annual average, unlike the Mediterranean and Red seas, which have comparable evaporative forcing. As a result, outflow from the gulf tends to be less dense than inflow from the Pacific. Winds over the gulf change direction with season, blowing northward in summer and southward in winter. This same seasonal pattern appears in near-surface transports averaged across the gulf. The thermohaline circulation, then, consists of outflow mostly between about 50 m and 250 m, inflow mostly between 250 m and 500 m, and a surface layer in which the direction of transport changes with seasonal changes in the large-scale winds. Using hydrographic observations from a section across the central gulf, total transport in or out of the northern gulf is estimated to be 0.9 Sv, heat gain from the atmosphere is estimated to be 20 to 50 W m-2, and evaporation is estimated to be 0.95 m yr-1. These estimates are annual averages, based on cruises from several years. Seasonal variations in thermohaline structure in the gulf are also examined and found to dominate the variance in temperature and density in the top 500 m of the water column. Salinity has little seasonal variability but does exhibit more horizontal variablility than temperature or density. Major year-to-year variations in thermohaline structure may be attributable to El Niño-Southern Oscillation

Numerical Modelling of the 1995 Dinar Earthquake Effects on Hydrodynamic Regime of Egirdir Lake

Directory of Open Access Journals (Sweden)

Murat Aksel

2017-11-01

Full Text Available The effect of earthquakes on closed and semi-closed water systems is a research topic that has been studied for many years. The lack of continuous measurement systems in closed and semi-closed water systems is insufficient to examine and investigate what has happened during the earthquake. The morphological structures of the lakes indicate the characteristics of the events that occurred during an earthquake. Due to the developing technology and research request, some monitoring, measurement stations are installed in some lakes, gulfs, estuaries, etc. systems. Today, both higher quality measurement and field data can be obtained, and more complicated processes are being explored with the help of faster computers. Computational fluid dynamics is currently used because of the difficulty in calculating hydrodynamic responses of lakes due to earthquake. Investigations on the effects of the earthquake condition on the desired closed / semi-closed water system studies by using numerical modelling have been continuing increasingly in recent years. Both the quality of the bathymetric data gathered from the field, the continuous acquisition of both dynamic water level measurement systems, and the use of new technologies and systems in the search for base materials contribute to the fact that we have more knowledge of the formation, behavior and effects of the sorts. In this study, 1995 Dinar Earthquake effects on Egirdir Lake hydrodynamic regime was investigated by numerical modelling approach.

76 FR 69136 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Reef Fish Fishery of the Gulf of...

Science.gov (United States)

2011-11-08

... interim measures to reduce overfishing of gag in the Gulf of Mexico (Gulf) implemented by a temporary rule... overfishing of gag in the Gulf by reducing the commercial quota for gag and, thus, the combined commercial... this rule is to reduce overfishing of the gag resource in the Gulf. [[Page 69137

77 FR 2960 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Reef Fish Fishery of the Gulf of...

Science.gov (United States)

2012-01-20

... the Caribbean, Gulf of Mexico, and South Atlantic; Reef Fish Fishery of the Gulf of Mexico; Exempted... and retention. This study, to be conducted in the exclusive economic zone (EEZ) of the Gulf of Mexico (Gulf) off Louisiana, is intended to better document the age structure and life history of fish...

77 FR 30507 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Reef Fish Fishery of the Gulf of...

Science.gov (United States)

2012-05-23

... the Caribbean, Gulf of Mexico, and South Atlantic; Reef Fish Fishery of the Gulf of Mexico; Exempted... and retention. This study, to be conducted in the exclusive economic zone (EEZ) of the Gulf of Mexico (Gulf), is intended to better document the age structure and life history of fish associated with...

Beyond the Gulf Metropolises

DEFF Research Database (Denmark)

Wippel, Steffen

2013-01-01

The extended studies on urbanisation in the Gulf region that came up in the early 2000s concentrated on the main centres with their worldwide-admired mega-projects and branding strategies. Only rather recently did a more general interest arise in the second-tier range of Gulf cities, which also s...

Microplastic pollution in lakes and lake shoreline sediments - A case study on Lake Bolsena and Lake Chiusi (central Italy).

Science.gov (United States)

Fischer, Elke Kerstin; Paglialonga, Lisa; Czech, Elisa; Tamminga, Matthias

2016-06-01

Rivers and effluents have been identified as major pathways for microplastics of terrestrial sources. Moreover, lakes of different dimensions and even in remote locations contain microplastics in striking abundances. This study investigates concentrations of microplastic particles at two lakes in central Italy (Lake Bolsena, Lake Chiusi). A total number of six Manta Trawls have been carried out, two of them one day after heavy winds occurred on Lake Bolsena showing effects on particle distribution of fragments and fibers of varying size categories. Additionally, 36 sediment samples from lakeshores were analyzed for microplastic content. In the surface waters 2.68 to 3.36 particles/m(3) (Lake Chiusi) and 0.82 to 4.42 particles/m(3) (Lake Bolsena) were detected, respectively. Main differences between the lakes are attributed to lake characteristics such as surface and catchment area, depth and the presence of local wind patterns and tide range at Lake Bolsena. An event of heavy winds and moderate rainfall prior to one sampling led to an increase of concentrations at Lake Bolsena which is most probable related to lateral land-based and sewage effluent inputs. The abundances of microplastic particles in sediments vary from mean values of 112 (Lake Bolsena) to 234 particles/kg dry weight (Lake Chiusi). Lake Chiusi results reveal elevated fiber concentrations compared to those of Lake Bolsena what might be a result of higher organic content and a shift in grain size distribution towards the silt and clay fraction at the shallow and highly eutrophic Lake Chiusi. The distribution of particles along different beach levels revealed no significant differences. Copyright © 2016 Elsevier Ltd. All rights reserved.

Gulf Coast Ecosystem Restoration Task Force---Gulf of Mexico Ecosystem Science Assessment and Needs

Science.gov (United States)

Walker, Shelby; Dausman, Alyssa M.; Lavoie, Dawn L.

2012-01-01

The Gulf Coast Ecosystem Restoration Task Force (GCERTF) was established by Executive Order 13554 as a result of recommendations from “America’s Gulf Coast: A Long-term Recovery Plan after the Deepwater Horizon Oil Spill” by Secretary of the Navy Ray Mabus (Mabus Report). The GCERTF consists of members from 11 Federal agencies and representatives from each State bordering the Gulf of Mexico. The GCERTF was charged to develop a holistic, long-term, science-based Regional Ecosystem Restoration Strategy for the Gulf of Mexico. Federal and State agencies staffed the GCERTF with experts in fields such as policy, budgeting, and science to help develop the Strategy. The Strategy was built on existing authorities and resources and represents enhanced collaboration and a recognition of the shared responsibility among Federal and State governments to restore the Gulf Coast ecosystem. In this time of severe fiscal constraints, Task Force member agencies and States are committed to establishing shared priorities and working together to achieve them.As part of this effort, three staffers, one National Oceanic and Atmospheric Administration (NOAA) scientist and two U.S. Geological Survey (USGS) scientists, created and led a Science Coordination Team (SCT) to guide scientific input into the development of the Gulf of Mexico Regional Ecosystem Restoration Strategy. The SCT leads from the GCERTF coordinated more than 70 scientists from the Federal and State Task Force member agencies to participate in development of a restoration-oriented science document focused on the entire Gulf of Mexico, from inland watersheds to the deep blue waters. The SCT leads and scientists were organized into six different working groups based on expanded goals from the Mabus Report: Coastal habitats are healthy and resilient.Living coastal and marine resources are healthy, diverse, and sustainable.Coastal communities are adaptive and resilient.Storm buffers are sustainable.Inland habitats and

Cogeneration feasibility study in the Gulf States Utilities service area

Energy Technology Data Exchange (ETDEWEB)

1979-12-01

Sites in the Gulf States Utilities service are considered for cogeneration feasibility studies. The sources of steam considered for the Orange, Texas and Geismar, Lake Charles, and North Baton Rouge, Louisiana sites include oil, coal, HTGR steamers, consolidated nuclear steam system, atmospheric fluidized-bed coal combustion, and coal gasification. Concepts concerning cogeneration fuel systems were categorized by technical applicability as: current technology (pulverized coal-fired boilers and fuel oil-fired boilers), advanced technology under development (HTGR steamers and the CNSS), and advanced technology for future development (atmospheric fluidized-bed boilers and coal gasification). In addition to providing data on cogeneration plant generally useful in the US, the study determined the technical and economic feasibility of steam and electric power cogeneration using coal and nuclear fuels for localized industrial complexes. Details on site selection, plant descriptions, cost estimates, economic analysis, and plant schedule and implementation. (MCW)

Major reproductive health characteristics in male Gulf War Veterans. The Danish Gulf War Study

DEFF Research Database (Denmark)

Ishøy, T; Andersson, A M; Suadicani, Poul Vilhelm

2001-01-01

The male reproductive system could have been affected by various hazardous agents and exposures during and in the aftermath of the Persian Gulf War scenario. We tested the hypothesis that, compared to controls, male Danish Gulf War Veterans would have adverse sex hormone levels, decreased fertility...

Population Structure, Abundance and Movement of Whale Sharks in the Arabian Gulf and the Gulf of Oman.

Science.gov (United States)

Robinson, David P; Jaidah, Mohammed Y; Bach, Steffen; Lee, Katie; Jabado, Rima W; Rohner, Christoph A; March, Abi; Caprodossi, Simone; Henderson, Aaron C; Mair, James M; Ormond, Rupert; Pierce, Simon J

2016-01-01

Data on the occurrence of whale sharks, Rhincodon typus, in the Arabian Gulf and Gulf of Oman were collected by dedicated boat surveys and via a public-sightings scheme during the period from 2011 to 2014. A total of 422 individual whale sharks were photo-identified from the Arabian Gulf and the northern Gulf of Oman during that period. The majority of sharks (81%, n = 341) were encountered at the Al Shaheen area of Qatar, 90 km off the coast, with the Musandam region of Oman a secondary area of interest. At Al Shaheen, there were significantly more male sharks (n = 171) than females (n = 78; X2 = 17.52, P 9 m individuals were visually assessed as pregnant. Connectivity among sharks sighted in Qatari, Omani and UAE waters was confirmed by individual spot pattern matches. A total of 13 identified sharks were re-sighted at locations other than that at which they were first sighted, including movements into and out of the Arabian Gulf through the Strait of Hormuz. Maximum likelihood techniques were used to model an estimated combined population for the Arabian Gulf and Gulf of Oman of 2837 sharks ± 1243.91 S.E. (95% C.I. 1720-6295). The Al Shaheen aggregation is thus the first site described as being dominated by mature males while the free-swimming pregnant females are the first reported from the Indian Ocean.

Danish Gulf War Veterans Revisited

DEFF Research Database (Denmark)

Nissen, Lars Ravnborg; Stoltenberg, Christian; Nielsen, Anni B Sternhagen

2016-01-01

OBJECTIVE: To examine the assumption that postdeployment incidence of sickness and other absence from work are higher among Gulf War Veterans compared with nonveterans. METHODS: A prospective registry study including a cohort of 721 Danish Gulf War Veterans and a control cohort of 3,629 nonveterans...... and nonveterans in the incidence rate of long-term sickness absence. After an initial short period (3 months) with elevated incidence rate of long-term absence from work among veterans, there was no difference between the cohorts. CONCLUSION: Among Danish Gulf War Veterans, no postdeployment increased risk...... outcomes and information on deployment history was studied using time-to-event analysis. The index date was the return date from the last deployment to the Gulf. The follow-up period was the time from index date until April 27, 2014. RESULTS: As the main finding, no difference was found between veterans...

Terrestrial CDOM in Lakes of Yamal Peninsula: Connection to Lake and Lake Catchment Properties

Directory of Open Access Journals (Sweden)

Yury Dvornikov

2018-01-01

Full Text Available In this study, we analyze interactions in lake and lake catchment systems of a continuous permafrost area. We assessed colored dissolved organic matter (CDOM absorption at 440 nm (a(440CDOM and absorption slope (S300–500 in lakes using field sampling and optical remote sensing data for an area of 350 km2 in Central Yamal, Siberia. Applying a CDOM algorithm (ratio of green and red band reflectance for two high spatial resolution multispectral GeoEye-1 and Worldview-2 satellite images, we were able to extrapolate the a(λCDOM data from 18 lakes sampled in the field to 356 lakes in the study area (model R2 = 0.79. Values of a(440CDOM in 356 lakes varied from 0.48 to 8.35 m−1 with a median of 1.43 m−1. This a(λCDOM dataset was used to relate lake CDOM to 17 lake and lake catchment parameters derived from optical and radar remote sensing data and from digital elevation model analysis in order to establish the parameters controlling CDOM in lakes on the Yamal Peninsula. Regression tree model and boosted regression tree analysis showed that the activity of cryogenic processes (thermocirques in the lake shores and lake water level were the two most important controls, explaining 48.4% and 28.4% of lake CDOM, respectively (R2 = 0.61. Activation of thermocirques led to a large input of terrestrial organic matter and sediments from catchments and thawed permafrost to lakes (n = 15, mean a(440CDOM = 5.3 m−1. Large lakes on the floodplain with a connection to Mordy-Yakha River received more CDOM (n = 7, mean a(440CDOM = 3.8 m−1 compared to lakes located on higher terraces.

Sanctuaries for lake trout in the Great Lakes

Science.gov (United States)

Stanley, Jon G.; Eshenroder, Randy L.; Hartman, Wilbur L.

1987-01-01

Populations of lake trout, severely depleted in Lake Superior and virtually extirpated from the other Great Lakes because of sea lamprey predation and intense fishing, are now maintained by annual plantings of hatchery-reared fish in Lakes Michigan, Huron, and Ontario and parts of Lake Superior. The extensive coastal areas of the Great Lakes and proximity to large populations resulted in fishing pressure on planted lake trout heavy enough to push annual mortality associated with sport and commercial fisheries well above the critical level needed to reestablish self-sustaining stocks. The interagency, international program for rehabilitating lake trout includes controlling sea lamprey abundance, stocking hatchery-reared lake trout, managing the catch, and establishing sanctuaries where harvest is prohibited. Three lake trout sanctuaries have been established in Lake Michigan: the Fox Island Sanctuary of 121, 500 ha, in the Chippewa-Ottawa Treaty fishing zone in the northern region of the lake; the Milwaukee Reef Sanctuary of 160, 000 ha in midlake, in boundary waters of Michigan and Wisconsin; and Julian's Reef Sanctuary of 6, 500 ha, in Illinois waters. In northern Lake Huron, Drummond Island Sanctuary of 55, 000 ha is two thirds in Indian treaty-ceded waters in Michigan and one third in Ontario waters of Canada. A second sanctuary, Six Fathom Bank-Yankee Reef Sanctuary, in central Lake Huron contains 168, 000 ha. Sanctuary status for the Canadian areas remains to be approved by the Provincial government. In Lake Superior, sanctuaries protect the spawning grounds of Gull Island Shoal (70, 000 ha) and Devils Island Shoal (44, 000 ha) in Wisconsin's Apostle Island area. These seven sanctuaries, established by the several States and agreed upon by the States, Indian tribes, the U.S. Department of the Interior, and the Province of Ontario, contribute toward solving an interjurisdictional fishery problem.

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

Digital Repository Service at National Institute of Oceanography (India)

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

and managers of coastal zones are also useful for identifying sensitive resources before a spill occurs (Jenson, 1998). In this way, protection priorities could be identified and established and cleanup strategies could be designed in advance. To deal... regions to oil spills. This research focuses on improving information about coastal environment mapping from remote sensing and GIS technology to generate maps of environmental sensitivity index for oil spill in Gulf of Kachchh and Gulf of Cambay...

The United States and the Arab Gulf Monarchies

International Nuclear Information System (INIS)

Kechichian, J.A.

1999-01-01

The United States has enduring strategic interests in the Persian Gulf region. To understand these interests and the Usa policy towards the Arab Gulf Monarchies, the french institute of international relations (IFRI) proposes this document. The following chapters are detailed: the United States and the Arab Gulf Monarchies, overview, Chief Unites States Objective: Access to oil, re-evaluating United States Foreign Policy in the Gulf, the second term (Usa strategy). (A.L.B.)

A 12,000-Year-Long, Annually-Resolved Varve Record Spanning the Last Interglacial from Lake Bosumtwi, Southern Ghana

Science.gov (United States)

McKay, N.; Overpeck, J. T.; Shanahan, T. M.; Peck, J. A.; Heil, C. W.; King, J. W.; Scholz, C. A.

2012-12-01

temperatures (SST) in Gulf of Guinea, including an abrupt drop in lake level that lasted about 500 years ca. 118 ka, corresponding to cooling in the Gulf of Guinea and much of the North Atlantic during the interval. The timing and duration of the event are comparable to the Late Eemian Aridity Pulse (LEAP) that is observed at several European sites, and has been interpreted to result from abrupt cooling in the North Atlantic, and possibly a reduction of Atlantic meridional overturning circulation. This scenario would likely result in drought in West Africa, so the aridity ca. 118 ka is the first indication that the LEAP occurred in Africa as well as Europe. The occurrence of quasiperiodic variability at multidecadal to centennial timescales is consistent with the hypothesis that slowly varying changes in Atlantic SST structure (e.g., the Atlantic Multidecadal Oscillation) drives long term hydrologic variability in the region.

Evolution of alkaline lakes - Lake Van case study

Science.gov (United States)

Tillman Meyer, Felix; Viehberg, Finn; Bahroun, Sonya; Wolf, Annabel; Immenhauser, Adrian; Kwiecien, Ola

2017-04-01

Lake Van in Eastern Anatolia (Turkey) is the largest terminal soda lake on Earth. The lake sedimentary profile covers ca. 600 ka (Stockhecke et al. 2014) Based on lithological changes, the presence of freshwater microfossils and close-to-freshwater pH value in the pore water, members of ICDP PALEOVAN concluded that Lake Van might have started as an open lake. Here we show paleontological and geochemical evidence in favour of this idea and constrain the time, when Lake Van likely transformed into a closed lake. Additionally we provide the first conceptual model of how this closure may have happened. Our archives of choice are inorganic and biogenic carbonates, separated by wet sieving. We identified microfossil assemblages (fraction > 125 µm) and performed high-resolution oxygen isotope (delta18O) and elemental (Mg/Ca, Sr/Ca) analyses of the fraction plants growing in the photic zone as food supply. These two aspects point to an increasing salinity in a shallowing lake. The delta18O values of inorganic carbonates are relatively low during the initial phase of Lake Van and increase abruptly (ca. 7‰) after 530 ka BP. At approximately the same time combination of Sr/Ca and Mg/Ca data suggest first occurrence of aragonite. Again, these findings suggest geochemical changes of the lake water concurrent with transition documented by microfossils. Comparison between Lake Van and Lake Ohrid (Lacey et al. 2016) delta18O data, precludes regional climate change (e.g.: increased evaporation) as the main driver of observed changes. With no evidence for increased volcanic or tectonic activity (e.g.: tephra layers, deformation structures, slumping) in the Lake Van sedimentary profile around 530 ka, it seems unlikely that a pyroclastic flow blocked the outflow of the lake. Alternatively, a portion of inflow has been diverged which might have caused a change in the hydrological balance and lake level falling below its outlet. However, as no geomorphological data confirming this

Bathymetry of Lake Erie and Lake Saint Clair

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lake Erie and Lake Saint Clair has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and geophysical data and...

77 FR 67303 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Reef Fish Fishery of the Gulf of...

Science.gov (United States)

2012-11-09

... interim measures to reduce overfishing of gray triggerfish in the Gulf of Mexico (Gulf) implemented by a... rule is to reduce overfishing of the gray triggerfish resource in the Gulf while the Council develops... necessary, to reduce overfishing. On April 19, 2012, the Council requested that NMFS implement a temporary...

Behavior and trends for Zn in Saronikos Gulf

Directory of Open Access Journals (Sweden)

Chalkiadakis O.

2013-04-01

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

75 FR 21512 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Reef Fish Fishery of the Gulf of...

Science.gov (United States)

2010-04-26

...: NMFS issues this final rule to implement Amendment 31 to the Fishery Management Plan for the Reef Fish Resources of the Gulf of Mexico (FMP) prepared by the Gulf of Mexico Fishery Management Council (Council... operation of the bottom longline component of the reef fish fishery in the eastern Gulf while maintaining...

Lake whitefish diet, condition, and energy density in Lake Champlain and the lower four Great Lakes following dreissenid invasions

Science.gov (United States)

Herbst, Seth J.; Marsden, J. Ellen; Lantry, Brian F.

2013-01-01

Lake Whitefish Coregonus clupeaformis support some of the most valuable commercial freshwater fisheries in North America. Recent growth and condition decreases in Lake Whitefish populations in the Great Lakes have been attributed to the invasion of the dreissenid mussels, zebra mussels Dreissena polymorpha and quagga mussels D. bugensis, and the subsequent collapse of the amphipod, Diporeia, a once-abundant high energy prey source. Since 1993, Lake Champlain has also experienced the invasion and proliferation of zebra mussels, but in contrast to the Great Lakes, Diporeia were not historically abundant. We compared the diet, condition, and energy density of Lake Whitefish from Lake Champlain after the dreissenid mussel invasion to values for those of Lake Whitefish from Lakes Michigan, Huron, Erie, and Ontario. Lake Whitefish were collected using gill nets and bottom trawls, and their diets were quantified seasonally. Condition was estimated using Fulton's condition factor (K) and by determining energy density. In contrast to Lake Whitefish from some of the Great Lakes, those from Lake Champlain Lake Whitefish did not show a dietary shift towards dreissenid mussels, but instead fed primarily on fish eggs in spring, Mysis diluviana in summer, and gastropods and sphaeriids in fall and winter. Along with these dietary differences, the condition and energy density of Lake Whitefish from Lake Champlain were high compared with those of Lake Whitefish from Lakes Michigan, Huron, and Ontario after the dreissenid invasion, and were similar to Lake Whitefish from Lake Erie; fish from Lakes Michigan, Huron, and Ontario consumed dreissenids, whereas fish from Lake Erie did not. Our comparisons of Lake Whitefish populations in Lake Champlain to those in the Great Lakes indicate that diet and condition of Lake Champlain Lake Whitefish were not negatively affected by the dreissenid mussel invasion.

Assessment of heavy metals pollution in bottom sediments of the Arabian Gulf after the Gulf War oil spill 1991

International Nuclear Information System (INIS)

Nasr, S.M.; Ahmed, M.H.; El-Raey, M.; Frihy, O.E.; Abdel Motti, A.

1999-01-01

The major objective of this study was to carry out a sequential geochemical extraction scheme for the partitioning of Fe, Mn, Co, Cu, Zn, Ni, Cr and Pb in the bottom sediments of the Arabian Gulf to detect any potential pollution impact on the gulf sediments following the 1991 gulf war oil spill, and to differentiate between anthropogenic inputs and natural background of heavy metals

Glacial lake inventory and lake outburst potential in Uzbekistan.

Science.gov (United States)

Petrov, Maxim A; Sabitov, Timur Y; Tomashevskaya, Irina G; Glazirin, Gleb E; Chernomorets, Sergey S; Savernyuk, Elena A; Tutubalina, Olga V; Petrakov, Dmitriy A; Sokolov, Leonid S; Dokukin, Mikhail D; Mountrakis, Giorgos; Ruiz-Villanueva, Virginia; Stoffel, Markus

2017-08-15

Climate change has been shown to increase the number of mountain lakes across various mountain ranges in the World. In Central Asia, and in particular on the territory of Uzbekistan, a detailed assessment of glacier lakes and their evolution over time is, however lacking. For this reason we created the first detailed inventory of mountain lakes of Uzbekistan based on recent (2002-2014) satellite observations using WorldView-2, SPOT5, and IKONOS imagery with a spatial resolution from 2 to 10m. This record was complemented with data from field studies of the last 50years. The previous data were mostly in the form of inventories of lakes, available in Soviet archives, and primarily included localized in-situ data. The inventory of mountain lakes presented here, by contrast, includes an overview of all lakes of the territory of Uzbekistan. Lakes were considered if they were located at altitudes above 1500m and if lakes had an area exceeding 100m 2 . As in other mountain regions of the World, the ongoing increase of air temperatures has led to an increase in lake number and area. Moreover, the frequency and overall number of lake outburst events have been on the rise as well. Therefore, we also present the first outburst assessment with an updated version of well-known approaches considering local climate features and event histories. As a result, out of the 242 lakes identified on the territory of Uzbekistan, 15% are considered prone to outburst, 10% of these lakes have been assigned low outburst potential and the remainder of the lakes have an average level of outburst potential. We conclude that the distribution of lakes by elevation shows a significant influence on lake area and hazard potential. No significant differences, by contrast, exist between the distribution of lake area, outburst potential, and lake location with respect to glaciers by regions. Copyright © 2017 Elsevier B.V. All rights reserved.

All-Cause Mortality Among US Veterans of the Persian Gulf War

Science.gov (United States)

Kang, Han K.; Bullman, Tim

2016-01-01

Objective: We determined cause-specific mortality prevalence and risks of Gulf War deployed and nondeployed veterans to determine if deployed veterans were at greater risk than nondeployed veterans for death overall or because of certain diseases or conditions up to 13 years after conflict subsided. Methods: Follow-up began when the veteran left the Gulf War theater or May 1, 1991, and ended on the date of death or December 31, 2004. We studied 621   901 veterans who served in the 1990-1991 Persian Gulf War and 746   247 veterans who served but were not deployed during the Gulf War. We used Cox proportional hazard models to calculate rate ratios adjusted for age at entry to follow-up, length of follow-up, race, sex, branch of service, and military unit. We compared the mortality of (1) Gulf War veterans with non–Gulf War veterans and (2) Gulf War army veterans potentially exposed to nerve agents at Khamisiyah in March 1991 with those not exposed. We compared standardized mortality ratios of deployed and nondeployed Gulf War veterans with the US population. Results: Male Gulf War veterans had a lower risk of mortality than male non–Gulf War veterans (adjusted rate ratio [aRR] = 0.97; 95% confidence interval [CI], 0.95-0.99), and female Gulf War veterans had a higher risk of mortality than female non–Gulf War veterans (aRR = 1.15; 95% CI, 1.03-1.28). Khamisiyah-exposed Gulf War army veterans had >3 times the risk of mortality from cirrhosis of the liver than nonexposed army Gulf War veterans (aRR = 3.73; 95% CI, 1.64-8.48). Compared with the US population, female Gulf War veterans had a 60% higher risk of suicide and male Gulf War veterans had a lower risk of suicide (standardized mortality ratio = 0.84; 95% CI, 0.80-0.88). Conclusion: The vital status and mortality risk of Gulf War and non–Gulf War veterans should continue to be investigated. PMID:28123229

75 FR 74650 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Reef Fish Fishery of the Gulf of...

Science.gov (United States)

2010-12-01

... issues this final temporary rule to implement interim measures to reduce overfishing of gag in the Gulf... this final temporary rule is to reduce overfishing of the gag resource in the Gulf. DATES: This rule is... rule is to reduce overfishing of the gag resource in the Gulf. No changes were made to this final rule...

Saudis map $450 million gulf spill cleanup

International Nuclear Information System (INIS)

Anon.

1991-01-01

This paper reports on Saudi Arabia which has earmarked about $450 million to clean up Persian Gulf beaches polluted by history's worst oil spills, created during the Persian Gulf crisis. Details of the proposed cleanup measures were outlined by Saudi environmental officials at a seminar on the environment in Dubai, OPEC News Agency reported. The seminar was sponsored by the Gulf Area Oil Companies Mutual Aid Organization, an environmental cooperative agency set up by Persian Gulf governments. Meantime, a Saudi government report has outlined early efforts designed to contain the massive oil spills that hit the Saudi coast before oil could contaminate water intakes at the huge desalination plants serving Riyadh and cooling water facilities at Al Jubail

Clinical Evaluation of a Proposed New Gulf War Syndrome

National Research Council Canada - National Science Library

Levine, Paul

2001-01-01

Thus far, studies on Gulf War veterans have not defined any syndrome specific to deployed Gulf War veterans, but have only suggested that Persian Gulf War veterans have a higher frequency of a number...

Curcumin Nanoparticle Therapy for Gulf War Illness

Science.gov (United States)

2017-10-01

AWARD NUMBER: W81XWH-16-1-0480 TITLE: Curcumin Nanoparticle Therapy for Gulf War Illness PRINCIPAL INVESTIGATOR: Ashok K. Shetty, Ph.D...Nanoparticle Therapy for Gulf War Illness 5a. CONTRACT NUMBER 5b. GRANT NUMBER W81XWH-16-1-0480 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Ashok K...biodegradable polymer nanosystems (nCUR) for alleviating cognitive, memory and mood impairments in a rat model of gulf war illness (GWI). Specific

Lake-level frequency analysis for Devils Lake, North Dakota

Science.gov (United States)

Wiche, Gregg J.; Vecchia, Aldo V.

1996-01-01

Two approaches were used to estimate future lake-level probabilities for Devils Lake. The first approach is based on an annual lake-volume model, and the second approach is based on a statistical water mass-balance model that generates seasonal lake volumes on the basis of seasonal precipitation, evaporation, and inflow. Autoregressive moving average models were used to model the annual mean lake volume and the difference between the annual maximum lake volume and the annual mean lake volume. Residuals from both models were determined to be uncorrelated with zero mean and constant variance. However, a nonlinear relation between the residuals of the two models was included in the final annual lakevolume model.Because of high autocorrelation in the annual lake levels of Devils Lake, the annual lake-volume model was verified using annual lake-level changes. The annual lake-volume model closely reproduced the statistics of the recorded lake-level changes for 1901-93 except for the skewness coefficient. However, the model output is less skewed than the data indicate because of some unrealistically large lake-level declines. The statistical water mass-balance model requires as inputs seasonal precipitation, evaporation, and inflow data for Devils Lake. Analysis of annual precipitation, evaporation, and inflow data for 1950-93 revealed no significant trends or long-range dependence so the input time series were assumed to be stationary and short-range dependent.Normality transformations were used to approximately maintain the marginal probability distributions; and a multivariate, periodic autoregressive model was used to reproduce the correlation structure. Each of the coefficients in the model is significantly different from zero at the 5-percent significance level. Coefficients relating spring inflow from one year to spring and fall inflows from the previous year had the largest effect on the lake-level frequency analysis.Inclusion of parameter uncertainty in the model

Lake trout in northern Lake Huron spawn on submerged drumlins

Science.gov (United States)

Riley, Stephen C.; Binder, Thomas; Wattrus, Nigel J.; Faust, Matthew D.; Janssen, John; Menzies, John; Marsden, J. Ellen; Ebener, Mark P.; Bronte, Charles R.; He, Ji X.; Tucker, Taaja R.; Hansen, Michael J.; Thompson, Henry T.; Muir, Andrew M.; Krueger, Charles C.

2014-01-01

Recent observations of spawning lake trout Salvelinus namaycush near Drummond Island in northern Lake Huron indicate that lake trout use drumlins, landforms created in subglacial environments by the action of ice sheets, as a primary spawning habitat. From these observations, we generated a hypothesis that may in part explain locations chosen by lake trout for spawning. Most salmonines spawn in streams where they rely on streamflows to sort and clean sediments to create good spawning habitat. Flows sufficient to sort larger sediment sizes are generally lacking in lakes, but some glacial bedforms contain large pockets of sorted sediments that can provide the interstitial spaces necessary for lake trout egg incubation, particularly if these bedforms are situated such that lake currents can penetrate these sediments. We hypothesize that sediment inclusions from glacial scavenging and sediment sorting that occurred during the creation of bedforms such as drumlins, end moraines, and eskers create suitable conditions for lake trout egg incubation, particularly where these bedforms interact with lake currents to remove fine sediments. Further, these bedforms may provide high-quality lake trout spawning habitat at many locations in the Great Lakes and may be especially important along the southern edge of the range of the species. A better understanding of the role of glacially-derived bedforms in the creation of lake trout spawning habitat may help develop powerful predictors of lake trout spawning locations, provide insight into the evolution of unique spawning behaviors by lake trout, and aid in lake trout restoration in the Great Lakes.

Sandwaves of the Gulf of Khambhat

Digital Repository Service at National Institute of Oceanography (India)

Vora, K.H.; Gujar, A.R.; Karisiddaiah, S.M.

In the Gulf of Khambhat (Gujarat, India) the best formed sandwaves are seen in the west close to the Eastern Sand Bank. With increasing clay content and clay cover of the sea bed, the sandwaves become poorly formed. In the southern part of the Gulf...

Lake sturgeon population characteristics in Rainy Lake, Minnesota and Ontario

Science.gov (United States)

Adams, W.E.; Kallemeyn, L.W.; Willis, D.W.

2006-01-01

Rainy Lake contains a native population of lake sturgeon Acipenser fulvescens that has been largely unstudied. The aims of this study were to document the population characteristics of lake sturgeon in Rainy Lake and to relate environmental factors to year-class strength for this population. Gill-netting efforts throughout the study resulted in the capture of 322 lake sturgeon, including 50 recaptures. Lake sturgeon in Rainy Lake was relatively plump and fast growing compared with a 32-population summary. Population samples were dominated by lake sturgeon between 110 and 150 cm total length. Age–structure analysis of the samples indicated few younger (<10 years) lake sturgeon, but the smallest gill net mesh size used for sampling was 102 mm (bar measure) and would not retain small sturgeon. Few lake sturgeon older than age 50 years were captured, and maximum age of sampled fish was 59 years. Few correlations existed between lake sturgeon year-class indices and both annual and monthly climate variables, except that mean June air temperature was positively correlated with year-class strength. Analysis of Rainy Lake water elevation and resulting lake sturgeon year-class strength indices across years yielded consistent but weak negative correlations between late April and early June, when spawning of lake sturgeon occurs. The baseline data collected in this study should allow Rainy Lake biologists to establish more specific research questions in the future.

Gulf of Mexico production still recovering

International Nuclear Information System (INIS)

Koen, A.D.

1992-01-01

This paper reports that the extent of damage caused by Hurricane Andrew to Gulf of Mexico oil and gas installations continues coming into focus. A preliminary tally by Minerals Management Service offers a reasonably complete summary of gulf production and pipeline systems damage detectable at the surface. MMS requires Outer Continental Shelf operators to inspect for underwater damage all platforms, pipelines, risers, and other structures within an 85 mile corridor along the path of Andrew's eye as it churned through the gulf. OCS operators have until Oct. 16 to submit plans for the Level II surveys

Zooplankton communities in a large prealpine lake, Lake Constance: comparison between the Upper and the Lower Lake

Directory of Open Access Journals (Sweden)

Gerhard MAIER

2005-08-01

Full Text Available The zooplankton communities of two basins of a large lake, Lake Constance, were compared during the years 2002 and 2003. The two basins differ in morphology, physical and chemical conditions. The Upper Lake basin has a surface area of 470 km2, a mean depth of 100 and a maximum depth of 250 m; the Lower Lake basin has a surface area of 62 km2, a mean depth of only 13 and a maximum depth of 40 m. Nutrient, chlorophyll-a concentrations and mean temperatures are somewhat higher in the Lower than in the Upper Lake. Total abundance of rotifers (number per m2 lake surface was higher and rotifer development started earlier in the year in the Lower than in the Upper Lake. Total abundance of crustaceans was higher in the Upper Lake in the year 2002; in the year 2003 no difference in abundance could be detected between the lake basins, although in summer crustacean abundance was higher in the Lower than in the Upper Lake. Crustacean communities differed significantly between lake basins while there was no apparent difference in rotifer communities. In the Lower Lake small crustaceans, like Bosmina spp., Ceriodaphnia pulchella and Thermocyclops oithonoides prevailed. Abundance (number per m2 lake surface of predatory cladocerans, large daphnids and large copepods was much lower in the Lower than in the Upper Lake, in particular during the summer months. Ordination with nonmetric multidimensional scaling (NMS separated communities of both lakes along gradients that correlated with temperature and chlorophyll a concentration. Clutches of copepods were larger in the Lower than in the Upper Lake. No difference could be detected in clutch size of large daphnids between lake basins. Our results show that zooplankton communities in different basins of Lake Constance can be very different. They further suggest that the lack of large crustaceans in particular the lack of large predatory cladocerans in the Lower Lake can have negative effects on growth and

Lake trout rehabilitation in Lake Erie: a case history

Science.gov (United States)

Cornelius, Floyd C.; Muth, Kenneth M.; Kenyon, Roger

1995-01-01

Native lake trout (Salvelinus namaycush) once thrived in the deep waters of eastern Lake Erie. The impact of nearly 70 years of unregulated exploitation and over 100 years of progressively severe cultural eutrophication resulted in the elimination of lake trout stocks by 1950. Early attempts to restore lake trout by stocking were unsuccessful in establishing a self-sustaining population. In the early 1980s, New York's Department of Environmental Conservation, Pennsylvania's Fish and Boat Commission, and the U.S. Fish and Wildlife Service entered into a cooperative program to rehabilitate lake trout in the eastern basin of Lake Erie. After 11 years of stocking selected strains of lake trout in U.S. waters, followed by effective sea lamprey control, lake trout appear to be successfully recolonizing their native habitat. Adult stocks have built up significantly and are expanding their range in the lake. Preliminary investigations suggest that lake trout reproductive habitat is still adequate for natural reproduction, but natural recruitment has not been documented. Future assessments will be directed toward evaluation of spawning success and tracking age-class cohorts as they move through the fishery.

Microbiology of Lonar Lake and other soda lakes

Science.gov (United States)

Paul Antony, Chakkiath; Kumaresan, Deepak; Hunger, Sindy; Drake, Harold L; Murrell, J Colin; Shouche, Yogesh S

2013-01-01

Soda lakes are saline and alkaline ecosystems that are believed to have existed throughout the geological record of Earth. They are widely distributed across the globe, but are highly abundant in terrestrial biomes such as deserts and steppes and in geologically interesting regions such as the East African Rift valley. The unusual geochemistry of these lakes supports the growth of an impressive array of microorganisms that are of ecological and economic importance. Haloalkaliphilic Bacteria and Archaea belonging to all major trophic groups have been described from many soda lakes, including lakes with exceptionally high levels of heavy metals. Lonar Lake is a soda lake that is centered at an unusual meteorite impact structure in the Deccan basalts in India and its key physicochemical and microbiological characteristics are highlighted in this article. The occurrence of diverse functional groups of microbes, such as methanogens, methanotrophs, phototrophs, denitrifiers, sulfur oxidizers, sulfate reducers and syntrophs in soda lakes, suggests that these habitats harbor complex microbial food webs that (a) interconnect various biological cycles via redox coupling and (b) impact on the production and consumption of greenhouse gases. Soda lake microorganisms harbor several biotechnologically relevant enzymes and biomolecules (for example, cellulases, amylases, ectoine) and there is the need to augment bioprospecting efforts in soda lake environments with new integrated approaches. Importantly, some saline and alkaline lake ecosystems around the world need to be protected from anthropogenic pressures that threaten their long-term existence. PMID:23178675

76 FR 20957 - Gulf of Mexico Fishery Management Council; Public Meeting

Science.gov (United States)

2011-04-14

... exceeded for Gulf group king mackerel, Gulf group Spanish mackerel, and Gulf group cobia. It also contains... framework procedure, and separate cobia into Atlantic and Gulf migratory groups. Similar measures are being...

Gulf of Mexico deep-water

International Nuclear Information System (INIS)

Ott, G.L.

1998-01-01

The deepwater Gulf of Mexico, an emerging basin with 20 BBOE resource potential, was discussed. Technologies are advancing and development options are increasing within the Gulf of Mexico deepwater environment. Deepwater offers significant rate potentials leading to strong cash flows. The projected steep rate of resources captured in the next five years show that there is a short window of opportunity to establish a business position. The major production variables are development costs and cycle time. There is a definite market for Gulf of Mexico products because U.S. energy demand is expected to outstrip U.S. supply. Present infrastructure is capable of moving large volumes of gas into major U.S. markets, but with the large number of projects currently underway, especially in the United States, supply could exceed capacity. 1 tab., 16 figs

Probiotic (VSL 3) for Gulf War Illness

Science.gov (United States)

2016-10-01

Award Number: W81XWH-10-1-0593 TITLE: Probiotic (VSL#3) for Gulf War Illness. PRINCIPAL INVESTIGATOR: Ashok Tuteja, M.D. M.P.H. CONTRACTING...NUMBER Probiotic (VSL#3) for Gulf War Illness. 5b. GRANT NUMBER W81XWH-10-1-0593 5c. PROGRAM ELEMENT NUMBER 6 . AUTHOR(S) 5d. PROJECT NUMBER Ashok...intestinal symptoms (fatigue, joint pain, insomnia, general stiffness and headache) associated with IBS. All of these symptoms are part of the Gulf War

Holocene Lake-Level Fluctuations of Lake Aricota, Southern Peru

Science.gov (United States)

Placzek, Christa; Quade, Jay; Betancourt, Julio L.

2001-09-01

Lacustrine deposits exposed around Lake Aricota, Peru (17° 22‧S), a 7.5-km2 lake dammed by debris flows, provide a middle to late Holocene record of lake-level fluctuations. Chronological context for shoreline deposits was obtained from radiocarbon dating of vascular plant remains and other datable material with minimal 14C reservoir effects (<350 yr). Diatomites associated with highstands several meters above the modern lake level indicate wet episodes. Maximum Holocene lake level was attained before 6100 14C yr B.P. and ended ∼2700 14C yr B.P. Moderately high lake levels occurred at 1700 and 1300 14C yr B.P. The highstand at Lake Aricota during the middle Holocene is coeval with a major lowstand at Lake Titicaca (16°S), which is only 130 km to the northeast and shares a similar climatology. Comparisons with other marine and terrestrial records highlight emerging contradictions over the nature of mid-Holocene climate in the central Andes.

Gulf of Mexico development

International Nuclear Information System (INIS)

Krenz, D.

1998-01-01

In recent years, the Gulf of Mexico (GOM) has seen significant deepwater growth. An overview of the GOM deepwater leaseholds by Shell and developments by competing companies is presented. Deepwater GOM developments, total production from the shelf and from deepwater wells, new offshore pipeline capacity and ownership, and processing plant capacity are also discussed. Significant deepwater growth in the Gulf is anticipated. Despite significant economic and technological challenges, the area is judged to be the prime exploration and production opportunity in the lower 48 states of the USA. tabs., figs

The diversity of benthic mollusks of Lake Victoria and Lake Burigi ...

African Journals Online (AJOL)

Molluscan diversity, abundance and distribution in sediments of Lake Victoria and its satellite lake, Lake Burigi, were investigated. The survey was carried out in January and February 2002 for Lake Victoria and in March and April 2002 for Lake Burigi. Ten genera were recorded from four zones of Lake Victoria while only ...

76 FR 65321 - Gulf War Veterans' Illnesses Task Force

Science.gov (United States)

2011-10-20

... DEPARTMENT OF VETERANS AFFAIRS Gulf War Veterans' Illnesses Task Force AGENCY: Department of... Veterans Affairs (VA) established the Gulf War Veterans' Illnesses Task Force (GWVI-TF) in August 2009 to conduct a comprehensive review of VA's approach to and programs addressing 1990-1991 Gulf War Veterans...

78 FR 28292 - Gulf War Veterans' Illnesses Task Force

Science.gov (United States)

2013-05-14

... DEPARTMENT OF VETERANS AFFAIRS Gulf War Veterans' Illnesses Task Force AGENCY: Department of... Veterans Affairs (VA) established the Gulf War Veterans' Illnesses Task Force (GWVI-TF) in August 2009 to conduct a comprehensive review of VA's approach to and programs addressing 1990-1991 Gulf War Veterans...

75 FR 16577 - Gulf War Veterans' Illnesses Task Force

Science.gov (United States)

2010-04-01

... DEPARTMENT OF VETERANS AFFAIRS Gulf War Veterans' Illnesses Task Force AGENCY: Department of... Veterans Affairs (VA) established the Gulf War Veterans' Illnesses Task Force (GWVI-TF) in August 2009 to conduct a comprehensive review of VA's approach to and programs addressing 1990-1991 Gulf War Veterans...

Lake Morphometry for NHD Lakes in Great Lakes Region 4 HUC

Data.gov (United States)

U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

50 CFR 226.214 - Critical habitat for Gulf sturgeon.

Science.gov (United States)

2010-10-01

... ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE MARINE MAMMALS DESIGNATED CRITICAL HABITAT § 226.214... Sound or the Gulf of Mexico. The Withlacoochee River main stem from Florida State Road 6, Madison and...) Unit 11: Florida Nearshore Gulf of Mexico Unit in Escambia, Santa Rosa, Okaloosa, Walton, Bay, and Gulf...

Western Gulf of Mexico lease sale draws weak response

International Nuclear Information System (INIS)

Koen, A.D.

1992-01-01

This paper reports that puny participation in the federal lease sale for the western Gulf of Mexico reflected a lack of open acreage on attractive prospects and the crisis sweeping the U.S. offshore oil and gas industry. Thirty-eight companies participating in the Minerals Management Service's Outer Continental Shelf Sale 141 offered 81 bids for 61 tracts in the western gulf planning area. That was the fewest bids offered in a western gulf sale since operators offered 52 bids for 41 tracts at Sale 105 in August 1986. The only Gulf of Mexico minerals sale to attract less bonus money was the MMS sulfur and salt sale in the central gulf in February 1988 in which $20.8 million was exposed

Spatial and temporal genetic diversity of lake whitefish (Coregonus clupeaformis (Mitchill)) from Lake Huron and Lake Erie

Science.gov (United States)

Stott, Wendylee; Ebener, Mark P.; Mohr, Lloyd; Hartman, Travis; Johnson, Jim; Roseman, Edward F.

2013-01-01

Lake whitefish (Coregonus clupeaformis (Mitchill)) are important commercially, culturally, and ecologically in the Laurentian Great Lakes. Stocks of lake whitefish in the Great Lakes have recovered from low levels of abundance in the 1960s. Reductions in abundance, loss of habitat and environmental degradation can be accompanied by losses of genetic diversity and overall fitness that may persist even as populations recover demographically. Therefore, it is important to be able to identify stocks that have reduced levels of genetic diversity. In this study, we investigated patterns of genetic diversity at microsatellite DNA loci in lake whitefish collected between 1927 and 1929 (historical period) and between 1997 and 2005 (contemporary period) from Lake Huron and Lake Erie. Genetic analysis of lake whitefish from Lakes Huron and Erie shows that the amount of population structuring varies from lake to lake. Greater genetic divergences among collections from Lake Huron may be the result of sampling scale, migration patterns and demographic processes. Fluctuations in abundance of lake whitefish populations may have resulted in periods of increased genetic drift that have resulted in changes in allele frequencies over time, but periodic genetic drift was not severe enough to result in a significant loss of genetic diversity. Migration among stocks may have decreased levels of genetic differentiation while not completely obscuring stock boundaries. Recent changes in spatial boundaries to stocks, the number of stocks and life history characteristics of stocks further demonstrate the potential of coregonids for a swift and varied response to environmental change and emphasise the importance of incorporating both spatial and temporal considerations into management plans to ensure that diversity is preserved.

Plutonium in the Gulf of Mexico

International Nuclear Information System (INIS)

Scott, M.R.; Salter, P.F.

The geochemistry of fallout plutonium in the sediments of the Gulf of Mexico was studied. A series of sediment cores was collected in a traverse from the deep Gulf of Mexico to the Mississippi Delta. The cores were sliced into 1 cm intervals and analyzed for plutonium. Explanations for the variations in concentration are presented

Water masses in the Gulf of Aden

Digital Repository Service at National Institute of Oceanography (India)

Al Saafani, M.A.; Shenoi, S.S.C.

Hydrographic data collected from Gulf of Aden since 1920 have been compiled to identify and refine the definitions of water masses in the Gulf of Aden (GA) and to describe their spatio-temporal variability. Four water masses have been identified...

Fishery potential of the Gulf of Kachchh

Digital Repository Service at National Institute of Oceanography (India)

Nair, V.R.; Govindan, K.; Ramaiah, Neelam; Gajbhiye, S.N.

Fishery potential of the interior Gulf of Kachchh and adjacent creek regions was reported for the first time as baseline data for future ecological assessment. The experimental trawling and gill netting indicated that the inner Gulf (av. 7.8 kg...

Energy density of lake whitefish Coregonus clupeaformis in Lakes Huron and Michigan

Science.gov (United States)

Pothoven, S.A.; Nalepa, T.F.; Madenjian, C.P.; Rediske, R.R.; Schneeberger, P.J.; He, J.X.

2006-01-01

We collected lake whitefish Coregonus clupeaformis off Alpena and Tawas City, Michigan, USA in Lake Huron and off Muskegon, Michigan USA in Lake Michigan during 2002–2004. We determined energy density and percent dry weight for lake whitefish from both lakes and lipid content for Lake Michigan fish. Energy density increased with increasing fish weight up to 800 g, and then remained relatively constant with further increases in fish weight. Energy density, adjusted for weight, was lower in Lake Huron than in Lake Michigan for both small (≤800 g) and large fish (>800 g). Energy density did not differ seasonally for small or large lake whitefish or between adult male and female fish. Energy density was strongly correlated with percent dry weight and percent lipid content. Based on data from commercially caught lake whitefish, body condition was lower in Lake Huron than Lake Michigan during 1981–2003, indicating that the dissimilarity in body condition between the lakes could be long standing. Energy density and lipid content in 2002–2004 in Lake Michigan were lower than data for comparable sized fish collected in 1969–1971. Differences in energy density between lakes were attributed to variation in diet and prey energy content as well as factors that affect feeding rates such as lake whitefish density and prey abundance.

Effects of lake trout refuges on lake whitefish and cisco in the Apostle Islands Region of Lake Superior

Science.gov (United States)

Zuccarino-Crowe , Chiara M.; Taylor, William W.; Hansen, Michael J.; Seider, Michael J.; Krueger, Charles C.

2016-01-01

Lake trout refuges in the Apostle Islands region of Lake Superior are analogous to the concept of marine protected areas. These refuges, established specifically for lake trout (Salvelinus namaycush) and closed to most forms of recreational and commercial fishing, were implicated as one of several management actions leading to successful rehabilitation of Lake Superior lake trout. To investigate the potential significance of Gull Island Shoal and Devils Island Shoal refuges for populations of not only lake trout but also other fish species, relative abundances of lake trout, lake whitefish (Coregonus clupeaformis), and cisco (Coregonus artedi) were compared between areas sampled inside versus outside of refuge boundaries. During 1982–2010, lake trout relative abundance was higher and increased faster inside the refuges, where lake trout fishing was prohibited, than outside the refuges. Over the same period, lake whitefish relative abundance increased faster inside than outside the refuges. Both evaluations provided clear evidence that refuges protected these species. In contrast, trends in relative abundance of cisco, a prey item of lake trout, did not differ significantly between areas inside and outside the refuges. This result did not suggest indirect or cascading refuge effects due to changes in predator levels. Overall, this study highlights the potential of species-specific refuges to benefit other fish species beyond those that were the refuges' original target. Improved understanding of refuge effects on multiple species of Great Lakes fishes can be valuable for developing rationales for refuge establishment and predicting associated fish community-level effects.

GULF OF MEXICO AQUATIC MORTALITY NETWORK (GMNET)

Science.gov (United States)

Five U.S. states share the northern coast of the Gulf, and each has a program to monitor mortalities of aquatic organisms (fish, shellfish, birds). However, each state has different standards, procedures, and documentation of mortality events. The Gulf of Mexico Aquatic Mortality...

Hazards of volcanic lakes: analysis of Lakes Quilotoa and Cuicocha, Ecuador

Directory of Open Access Journals (Sweden)

G. Gunkel

2008-01-01

Full Text Available Volcanic lakes within calderas should be viewed as high-risk systems, and an intensive lake monitoring must be carried out to evaluate the hazard of potential limnic or phreatic-magmatic eruptions. In Ecuador, two caldera lakes – Lakes Quilotoa and Cuicocha, located in the high Andean region >3000 a.s.l. – have been the focus of these investigations. Both volcanoes are geologically young or historically active, and have formed large and deep calderas with lakes of 2 to 3 km in diameter, and 248 and 148 m in depth, respectively. In both lakes, visible gas emissions of CO₂ occur, and an accumulation of CO₂ in the deep water body must be taken into account.

Investigations were carried out to evaluate the hazards of these volcanic lakes, and in Lake Cuicocha intensive monitoring was carried out for the evaluation of possible renewed volcanic activities. At Lake Quilotoa, a limnic eruption and diffuse CO₂ degassing at the lake surface are to be expected, while at Lake Cuicocha, an increased risk of a phreatic-magmatic eruption exists.

Fish larvae from the Gulf of California

Directory of Open Access Journals (Sweden)

Gerardo Aceves-Medina

2003-03-01

Full Text Available Taxonomic composition of fish larvae was analysed from 464 plankton samples obtained during 10 oceanographic surveys in the Gulf of California between 1984 and 1988. We identified 283 taxa: 173 species, 57 genera, and 53 families. Tropical and subtropical species predominated except during the winter, when temperate-subarctic species were dominant. The most abundant species were the mesopelagic Benthosema panamense, Triphoturus mexicanus and Vinciguerria lucetia, but the coastal pelagic species Engraulis mordax, Opisthonema spp., Sardinops caeruleus and Scomber japonicus were also prominent. The taxonomic composition of the ichthyoplankton shows the seasonality of the Gulf as well as environmental changes that occurred between the 1984-1987 warm period and the 1956-1957 cool period previously reported. The presence of E. mordax larvae as one of the most abundant species in the Gulf provides evidence of the reproduction of this species two years before the development of the northern anchovy fishery and the decline of the sardine fishery in the Gulf of California.

Influence of the Gulf Stream on the troposphere.

Science.gov (United States)

Minobe, Shoshiro; Kuwano-Yoshida, Akira; Komori, Nobumasa; Xie, Shang-Ping; Small, Richard Justin

2008-03-13

The Gulf Stream transports large amounts of heat from the tropics to middle and high latitudes, and thereby affects weather phenomena such as cyclogenesis and low cloud formation. But its climatic influence, on monthly and longer timescales, remains poorly understood. In particular, it is unclear how the warm current affects the free atmosphere above the marine atmospheric boundary layer. Here we consider the Gulf Stream's influence on the troposphere, using a combination of operational weather analyses, satellite observations and an atmospheric general circulation model. Our results reveal that the Gulf Stream affects the entire troposphere. In the marine boundary layer, atmospheric pressure adjustments to sharp sea surface temperature gradients lead to surface wind convergence, which anchors a narrow band of precipitation along the Gulf Stream. In this rain band, upward motion and cloud formation extend into the upper troposphere, as corroborated by the frequent occurrence of very low cloud-top temperatures. These mechanisms provide a pathway by which the Gulf Stream can affect the atmosphere locally, and possibly also in remote regions by forcing planetary waves. The identification of this pathway may have implications for our understanding of the processes involved in climate change, because the Gulf Stream is the upper limb of the Atlantic meridional overturning circulation, which has varied in strength in the past and is predicted to weaken in response to human-induced global warming in the future.

Principles of lake sedimentology

International Nuclear Information System (INIS)

Janasson, L.

1983-01-01

This book presents a comprehensive outline on the basic sedimentological principles for lakes, and focuses on environmental aspects and matters related to lake management and control-on lake ecology rather than lake geology. This is a guide for those who plan, perform and evaluate lake sedimentological investigations. Contents abridged: Lake types and sediment types. Sedimentation in lakes and water dynamics. Lake bottom dynamics. Sediment dynamics and sediment age. Sediments in aquatic pollution control programmes. Subject index

77 FR 18307 - Gulf War Veterans' Illnesses Task Force Report

Science.gov (United States)

2012-03-27

... DEPARTMENT OF VETERANS AFFAIRS Gulf War Veterans' Illnesses Task Force Report AGENCY: Department...) established the Gulf War Veterans' Illnesses Task Force (GWVI-TF) in August 2009 to conduct a comprehensive review of VA policies and programs addressing 1990-1991 Gulf War Veterans' illnesses. The GWVI-TF...

Lake Afdera: a threatened saline lake in Ethiopia | Getahun | SINET ...

African Journals Online (AJOL)

Lake Afdera is a saline lake located in the Afar region, Northern Ethiopia. Because of its inaccessibility it is one of the least studied lakes of the country. It supports life including three species of fish of which two are endemic. Recently, reports are coming out that this lake is used for salt extraction. This paper gives some ...

US Gulf operators take the long view

International Nuclear Information System (INIS)

Flatern, Rick von

1999-01-01

Oil projects in the Gulf of Mexico have suffered from the crash in oil prices in the mid-1980s, however as these projects tend to be long-term and therefore less sensitive to current oil prices, many are continuing to be funded. It is now believed by deepwater exploration operators that the Gulf of Mexico may be one of the world's most promising sources of new reserves. This article analyses the likely future exploration of deepwater reserves by major companies such as Shell, noted for its capital intensive and technologically innovative activity in the Gulf, as well as the newer, smaller independent operators. (UK)

76 FR 59102 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Spiny Lobster Fishery of the Gulf...

Science.gov (United States)

2011-09-23

... Atlantic; Spiny Lobster Fishery of the Gulf of Mexico and South Atlantic; Amendment 10 AGENCY: National... Fishery Management Plan for the Spiny Lobster Fishery of the Gulf of Mexico and South Atlantic (FMP), as... implemented, this rule would revise the lobster species contained within the fishery management unit...

76 FR 75488 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Spiny Lobster Fishery of the Gulf...

Science.gov (United States)

2011-12-02

... Atlantic; Spiny Lobster Fishery of the Gulf of Mexico and South Atlantic; Amendment 10 AGENCY: National... Plan for the Spiny Lobster Fishery of the Gulf of Mexico and South Atlantic (FMP), as prepared and... the lobster species contained within the fishery management unit; establishes an annual catch limit...

Statewide summary for Mississippi: Chapter H in Emergent wetlands status and trends in the northern Gulf of Mexico: 1950-2010

Science.gov (United States)

Handley, Larry; Spear, Kathryn A.; Leggett, Ali; Thatcher, Cindy A.

2012-01-01

The Mississippi coastline is 113 linear kilometers (70 miles) long and its estuaries cover approximately 594 km (369 mi; Figure 1) (Handley and others, 2007). It has a man-made sand beach 43.5 km (27 mi) long and 595.5 km (370 mi) of shoreline (Klein and others, b., 1998). The Mississippi Sound extends across the coastal waters of the State and encompasses 175,412 ha (433,443 acres). It is bordered by the Mississippi coast; Mobile Bay, Ala.; the Gulf Islands National Seashore barrier islands; and Lake Borgne, La. The watersheds and drainages feeding into Mississippi Sound, excluding tidal exchange from the Gulf of Mexico, include Lake Borgne, Pearl River, Jourdan River, Wolf River, Biloxi River, Tchoutacabouffa River, Pascagoula River, and Mobile Bay. The Pascagoula River is one of the last undammed rivers in the continental U.S. and the only undammed river flowing into the Gulf of Mexico. Freshwater inflow into Mississippi Sound, excluding that from Mobile Bay, averages 882.4 m3 per second (30,806 ft3 per second). The Mississippi coastal zone contains approximately one-third of the State’s 120 ecological communities (Klein and others, a., 1998). Regional land use includes silviculture, agriculture, and urban development, including several coastal casinos. Commercial shipping, shipbuilding, phosphate rock refinement, and electric power generation companies include some of the industrial complexes found along the Mississippi coast. The three counties found along the Mississippi coast, Hancock, Harrison, and Jackson Counties, had a total population of 370,702 as of 2010, constituting 12.5 percent of the State’s population (U.S. Census Bureau, 2010). These counties cover over 160.9 km (100 mi) of coastline and are one of the fastest growing regions in the state (Klein and others, b., 1998).The casino industry, military installations, trade, and manufacturing provide most jobs in coastal Mississippi. Two major deep-water ports exist in coastal Mississippi

Water quality of Lake Austin and Town Lake, Austin, Texas

Science.gov (United States)

Andrews, Freeman L.; Wells, Frank C.; Shelby, Wanda J.; McPherson, Emma

1988-01-01

Lake Austin and Town Lake are located on the Colorado River in Travis County, central Texas, and serve as a source of water for municipal and industrial water supplies, electrical-power generation, and recreation for more than 500,000 people in the Austin metropolitan area. Lake Austin, located immediately downstream of Lake Travis, extends for more than 20 miles into the western edge of the city of Austin. Town Lake extends through the downtown area of the city of Austin for nearly 6 miles where the Colorado River is impounded by Longhorn Dam.

Gulf Shrimp System

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Gulf of Mexico Shrimp Landings - This data set contains catch (landed catch) and effort for fishing trips made by the larger vessels that fish near and offshore for...

Continental breakup by oblique extension: the Gulf of California

Science.gov (United States)

van Wijk, J.; Axen, G. J.

2017-12-01

We address two aspects of oblique extension: 1) the evolution of pull-apart basins, and how/when they may evolve into seafloor spreading segments; and 2) the formation of microcontinents. The Gulf of California formed by oblique extension. Breakup resulted in oceanic crust generation in the southern and central parts, while in the northern Gulf/Salton Trough a thick layer of (meta-)sediments overlies thinned continental crust. We propose a simple mechanism to explain this N-S variation. We assume that oblique rifting of the proto-Gulf province resulted in pull-apart basins, and use numerical models to show that such pull-apart basins do not develop into seafloor spreading segments when their length-to-width ratios are small, as is the case in the northern Gulf. In the central and southern Gulf the length-to-width ratios were larger, promoting continent rupture. The mechanisms behind this fate of pull-apart basins will be discussed in the presentation. In the southern Gulf, potential field models show that the Tamayo Bank in the southern Gulf is likely a microcontinent, separated from the main continent by the Tamayo trough. The thickness of the ocean crust in the Tamayo trough is anomalously small, suggesting that initial seafloor spreading was magma-starved and unsuccessful, causing the location of rifting and seafloor spreading to jump. As a consequence a sliver of continent broke off, forming the microcontinent. We suggest that worldwide this may be a common process for microcontinent formation.

Epidemiological Studies Persian Gulf War Illnesses Persian Gulf Women's Health Linkage Study

National Research Council Canada - National Science Library

Klemm, Rebecca

1997-01-01

The Persian Gulf Women's Health Linkage Study will provide baseline health and risk factor information to estimate the prevalence of selected health conditions, with an emphasis on reproductive health...

Refuge Lake Reclassification in 620 Minnesota Cisco Lakes under Future Climate Scenarios

Directory of Open Access Journals (Sweden)

Liping Jiang

2017-09-01

Full Text Available Cisco (Coregonus artedi is the most common coldwater stenothermal fish in Minnesota lakes. Water temperature (T and dissolved oxygen (DO in lakes are important controls of fish growth and reproduction and likely change with future climate warming. Built upon a previous study, this study uses a modified method to identify which of 620 cisco lakes in Minnesota can still support cisco populations under future climate and therefore be classified as cisco refuge lakes. The previous study used oxythermal stress parameter TDO3, the temperature at DO of 3 mg/L, simulated only from deep virtual lakes to classify 620 cisco lakes. Using four categories of virtual but representative cisco lakes in modified method, a one-dimensional water quality model MINLAKE2012 was used to simulate daily T and DO profiles in 82 virtual lakes under the past (1961–2008 and two future climate scenarios. A multiyear average of 31-day largest TDO3 over variable benchmark (VB periods, AvgATDO3VB, was calculated from simulated T and DO profiles using FishHabitat2013. Contour plots of AvgATDO3VB for four categories of virtual lakes were then developed to reclassify 620 cisco lakes into Tier 1 (AvgATDO3VB < 11 °C or Tier 2 refuge lakes, and Tier 3 non-refuge lakes (AvgATDO3VB > 17 °C. About 20% of 620 cisco lakes are projected to be refuge lakes under future climate scenarios, which is a more accurate projection (improving the prediction accuracy by ~6.5% from the previous study since AvgATDO3VB was found to vary by lake categories.

Watershed vs. within-lake drivers of nitrogen: phosphorus dynamics in shallow lakes.

Science.gov (United States)

Ginger, Luke J; Zimmer, Kyle D; Herwig, Brian R; Hanson, Mark A; Hobbs, William O; Small, Gaston E; Cotner, James B

2017-10-01

Research on lake eutrophication often identifies variables affecting amounts of phosphorus (P) and nitrogen (N) in lakes, but understanding factors influencing N:P ratios is important given its influence on species composition and toxin production by cyanobacteria. We sampled 80 shallow lakes in Minnesota (USA) for three years to assess effects of watershed size, proportion of watershed as both row crop and natural area, fish biomass, and lake alternative state (turbid vs. clear) on total N : total P (TN : TP), ammonium, total dissolved phosphorus (TDP), and seston stoichiometry. We also examined N:P stoichiometry in 20 additional lakes that shifted states during the study. Last, we assessed the importance of denitrification by measuring denitrification rates in sediment cores from a subset of 34 lakes, and by measuring seston δ 15 N in four additional experimental lakes before and after they were experimentally manipulated from turbid to clear states. Results showed alternative state had the largest influence on overall N:P stoichiometry in these systems, as it had the strongest relationship with TN : TP, seston C:N:P, ammonium, and TDP. Turbid lakes had higher N at given levels of P than clear lakes, with TN and ammonium 2-fold and 1.4-fold higher in turbid lakes, respectively. In lakes that shifted states, TN was 3-fold higher in turbid lakes, while TP was only 2-fold higher, supporting the notion N is more responsive to state shifts than is P. Seston δ 15 N increased after lakes shifted to clear states, suggesting higher denitrification rates may be important for reducing N levels in clear states, and potential denitrification rates in sediment cores were among the highest recorded in the literature. Overall, our results indicate lake state was a primary driver of N:P dynamics in shallow lakes, and lakes in clear states had much lower N at a given level of P relative to turbid lakes, likely due to higher denitrification rates. Shallow lakes are often

76 FR 54727 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Spiny Lobster Fishery of the Gulf...

Science.gov (United States)

2011-09-02

... RIN 0648-AY72 Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Spiny Lobster Fishery of...) have submitted Amendment 10 to the Fishery Management Plan for the Spiny Lobster Fishery of the Gulf of... actions to revise the lobster species contained within the fishery management unit; revise definitions of...

Changes in Rongbuk lake and Imja lake in the Everest region of Himalaya

Science.gov (United States)

Chen, W.; Doko, T.; Liu, C.; Ichinose, T.; Fukui, H.; Feng, Q.; Gou, P.

2014-12-01

The Himalaya holds the world record in terms of range and elevation. It is one of the most extensively glacierized regions in the world except the Polar Regions. The Himalaya is a region sensitive to climate change. Changes in the glacial regime are indicators of global climate changes. Since the second half of the last century, most Himalayan glaciers have melted due to climate change. These changes directly affected the changes of glacial lakes in the Himalayan region due to the glacier retreat. New glacial lakes are formed, and a number of them have expanded in the Everest region of the Himalayas. This paper focuses on the two glacial lakes which are Imja Lake, located at the southern slope, and Rongbuk Lake, located at the northern slope in the Mt. Everest region, Himalaya to present the spatio-temporal changes from 1976 to 2008. Topographical conditions between two lakes were different (Kruskal-Wallis test, p < 0.05). Rongbuk Lake was located at 623 m higher than Imja Lake, and radiation of Rongbuk Lake was higher than the Imja Lake. Although size of Imja Lake was larger than the Rongbuk Lake in 2008, the growth speed of Rongbuk Lake was accelerating since 2000 and exceeds Imja Lake in 2000-2008. This trend of expansion of Rongbuk Lake is anticipated to be continued in the 21st century. Rongbuk Lake would be the biggest potential risk of glacial lake outburst flood (GLOF) at the Everest region of Himalaya in the future.

Lake-wide distribution of Dreissena in Lake Michigan, 1999

Science.gov (United States)

Fleischer, Guy W.; DeSorcie, Timothy J.; Holuszko, Jeffrey D.

2001-01-01

The Great Lakes Science Center has conducted lake-wide bottom trawl surveys of the fish community in Lake Michigan each fall since 1973. These systematic surveys are performed at depths of 9 to 110 m at each of seven index sites around Lake Michigan. Zebra mussel (Dreissena polymorpha) populations have expanded to all survey locations and at a level to sufficiently contribute to the bottom trawl catches. The quagga (Dreissena bugensis), recently reported in Lake Michigan, was likely in the catches though not recognized. Dreissena spp. biomass ranged from about 0.6 to 15 kg/ha at the various sites in 1999. Dreissenid mussels were found at depths of 9 to 82 m, with their peak biomass at 27 to 46 m. The colonization of these exotic mussels has ecological implications as well as potential ramifications on the ability to sample fish consistently and effectively with bottom trawls in Lake Michigan.

Free and forced Rossby normal modes in a rectangular gulf of arbitrary orientation

Science.gov (United States)

Graef, Federico

2016-09-01

A free Rossby normal mode in a rectangular gulf of arbitrary orientation is constructed by considering the reflection of a Rossby mode in a channel at the head of the gulf. Therefore, it is the superposition of four Rossby waves in an otherwise unbounded ocean with the same frequency and wavenumbers perpendicular to the gulf axis whose difference is equal to 2mπ/W, where m is a positive integer and W the gulf's width. The lower (or higher) modes with small m (or large m) are oscillatory (evanescent) in the coordinate along the gulf; these are elucidated geometrically. However for oceanographically realistic parameter values, most of the modes are evanescent. When the gulf is forced at the mouth with a single Fourier component, the response is in general an infinite sum of modes that are needed to match the value of the streamfunction at the gulf's entrance. The dominant mode of the response is the resonant one, which corresponds to forcing with a frequency ω and wavenumber normal to the gulf axis η appropriate to a gulf mode: η =- β sin α/(2ω) ± Mπ/W, where α is the angle between the gulf's axis and the eastern direction (+ve clockwise) and M the resonant's mode number. For zonal gulfs ω drops out of the resonance condition. For the special cases η = 0 in which the free surface goes up and down at the mouth with no flow through it, or a flow with a sinusoidal profile, resonant modes can get excited for very specific frequencies (only for non-zonal gulfs in the η = 0 case). The resonant mode is around the annual frequency for a wide range of gulf orientations α ∈ [40°, 130°] or α ∈ [220°, 310°] and gulf widths between 150 and 200 km; these include the Gulf of California and the Adriatic Sea. If η is imaginary, i.e. a flow with an exponential profile, there is no resonance. In general less modes get excited if the gulf is zonally oriented.

Northern Gulf Littoral Initiative (NGLI), Geology and Physical Properties of Marine Sediments in the N.E. Gulf of Mexico: Data Report

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Northern Gulf Littoral Initiative (NGLI), Geology and Physical Properties of Marine Sediments in the N.E. gulf of Mexico: Data Report, was produced by the U.S....

Large Lakes Dominate CO2 Evasion From Lakes in an Arctic Catchment

Science.gov (United States)

Rocher-Ros, Gerard; Giesler, Reiner; Lundin, Erik; Salimi, Shokoufeh; Jonsson, Anders; Karlsson, Jan

2017-12-01

CO2 evasion from freshwater lakes is an important component of the carbon cycle. However, the relative contribution from different lake sizes may vary, since several parameters underlying CO2 flux are size dependent. Here we estimated the annual lake CO2 evasion from a catchment in northern Sweden encompassing about 30,000 differently sized lakes. We show that areal CO2 fluxes decreased rapidly with lake size, but this was counteracted by the greater overall coverage of larger lakes. As a result, total efflux increased with lake size and the single largest lake in the catchment dominated the CO2 evasion (53% of all CO2 evaded). By contrast, the contribution from the smallest ponds (about 27,000) was minor (evasion at the landscape scale.

Lake Michigan lake trout PCB model forecast post audit

Science.gov (United States)

Scenario forecasts for total PCBs in Lake Michigan (LM) lake trout were conducted using the linked LM2-Toxics and LM Food Chain models, supported by a suite of additional LM models. Efforts were conducted under the Lake Michigan Mass Balance Study and the post audit represents th...

77 FR 25116 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Spiny Lobster Fishery of the Gulf...

Science.gov (United States)

2012-04-27

...-BB44 Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Spiny Lobster Fishery of the Gulf... (Councils) have submitted Amendment 11 to the Fishery Management Plan for the Spiny Lobster Fishery of the... proposes to limit spiny lobster fishing using trap gear in certain areas in the exclusive economic zone off...

Gulf operators resuming production

International Nuclear Information System (INIS)

Koen, A.D.

1992-01-01

This paper reports that Gulf of Mexico operators last week were gradually restoring production at installations struck by Hurricane Andrew. The Minerals Management Service continued receiving reports of more damage. By the end of the day Sept. 8, MMS had received reports of damage to 83 pipeline segments and 193 platforms and satellite installations. Damage reports listed 112 installations with structural damage, 13 platforms toppled and five leaning, and 30 satellite platforms toppled and 33 leaning. But despite the extent of damage the storm inflicted on oil and gas installations in the gulf, it pales in comparison to the misery and suffering the storm caused in Florida and Louisiana, an oil company official said

Using Satellite Imagery to Monitor the Major Lakes; Case Study Lake Hamun

Science.gov (United States)

Norouzi, H.; Islam, R.; Bah, A.; AghaKouchak, A.

2015-12-01

Proper lakes function can ease the impact of floods and drought especially in arid and semi-arid regions. They are important environmentally and can directly affect human lives. Better understanding of the effect of climate change and human-driven changes on lakes would provide invaluable information for policy-makers and local people. As part of a comprehensive study, we aim to monitor the land-cover/ land-use changes in the world's major lakes using satellite observations. As a case study, Hamun Lake which is a pluvial Lake, also known as shallow Lake, located on the south-east of Iran and adjacent to Afghanistan, and Pakistan borders is investigated. The Lake is the main source of resources (agriculture, fishing and hunting) for the people around it and politically important in the region since it is shared among three different countries. The purpose of the research is to find the Lake's area from 1972 to 2015 and to see if any drought or water resources management has affected the lake. Analyzing satellites imagery from Landsat shows that the area of the Lake changes seasonally and intra-annually. Significant seasonal effects are found in 1975,1977, 1987, 1993, 1996, 1998, 2000, 2009 and 2011, as well as, substantial amount of shallow water is found throughout the years. The precipitation records as well as drought historical records are studied for the lake's basin. Meteorological studies suggest that the drought, decrease of rainfalls in the province and the improper management of the Lake have caused environmental, economic and geographical consequences. The results reveal that lake has experienced at least two prolong dryings since 1972 which drought cannot solely be blamed as main forcing factor.Proper lakes function can ease the impact of floods and drought especially in arid and semi-arid regions. They are important environmentally and can directly affect human lives. Better understanding of the effect of climate change and human-driven changes on lakes

75 FR 63786 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Reef Fish Fishery of the Gulf of...

Science.gov (United States)

2010-10-18

... interim measures to reduce overfishing of gag in the Gulf of Mexico (Gulf). This proposed rule would... Fishery Management Council (Council). The intended effect of this proposed rule is to reduce overfishing... Act requires NMFS and regional fishery management councils to prevent overfishing and achieve, on a...

75 FR 63780 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Reef Fish Fishery of the Gulf of...

Science.gov (United States)

2010-10-18

... shallow water grouper (SWG) species, and require vessels with valid commercial Gulf of Mexico (Gulf) reef... that the stock continues to be neither overfished nor undergoing overfishing. However, this update... migratory species (HMS) species and relatively less dependent on landings of deep-water grouper species. On...

Sea snakes (Elapidae, Hydrophiinae) in their westernmost extent: an updated and illustrated checklist and key to the species in the Persian Gulf and Gulf of Oman

Science.gov (United States)

Rezaie-Atagholipour, Mohsen; Ghezellou, Parviz; Hesni, Majid Askari; Dakhteh, Seyyed Mohammad Hashem; Ahmadian, Hooman; Vidal, Nicolas

2016-01-01

Abstract The Persian Gulf is known as the westernmost distribution limit for sea snakes, except for Hydrophis platurus (Linnaeus, 1766) that reaches southeastern Africa. Previous identification guides for sea snakes of the Persian Gulf and its adjacent waters in the Gulf of Oman were based on old data and confined mostly to written descriptions. Therefore, a series of field surveys were carried out in 2013 and 2014 through Iranian coastal waters of both gulfs to provide a comprehensive sampling of sea snakes in the area. This paper presents an illustrated and updated checklist and identification tool for sea snakes in the Persian Gulf and Gulf of Oman, which are based on new material and a review of the literature. This checklist includes ten species of marine hydrophiines, of which one, Microcephalophis cantoris (Günther, 1864), is a new record for the area. All specimens examined herein are deposited and available at the Zoological Museum of Shahid Bahonar University of Kerman, Kerman province, Iran. PMID:27843383

75 FR 64171 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Reef Fish Fishery of the Gulf of...

Science.gov (United States)

2010-10-19

... prevent overfishing of Gulf greater amberjack. DATES: Closure is effective 12:01 a.m., local time, October... harvest to the quota is crucial to meeting the legal requirements to prevent and end overfishing and.... This closure is intended to prevent overfishing of Gulf greater amberjack and increase the likelihood...

77 FR 8810 - Gulf of Mexico Fishery Management Council; Public Meetings

Science.gov (United States)

2012-02-15

.... SUMMARY: The Gulf of Mexico Fishery Management Council (Council) will convene its Law Enforcement Advisory... East Beach Blvd., Gulfport, MS 39501. Council address: Gulf of Mexico Fishery Management Council, 2203..., Deputy Executive Director, Gulf of Mexico Fishery Management Council; telephone: (813) 348-1630...

75 FR 7444 - Gulf of Mexico Fishery Management Council; Public Meetings

Science.gov (United States)

2010-02-19

.... SUMMARY: The Gulf of Mexico Fishery Management Council (Council) will convene its Law Enforcement Advisory...., Orange Beach, AL 36561. Council address: Gulf of Mexico Fishery Management Council, 2203 North Lois... Director, Gulf of Mexico Fishery Management Council; telephone: (813) 348-1630. SUPPLEMENTARY INFORMATION...

Spatial distribution of seepage at a flow-through lake: Lake Hampen, Western Denmark

DEFF Research Database (Denmark)

Kidmose, Jacob Baarstrøm; Engesgaard, Peter Knudegaard; Nilsson, Bertel

2011-01-01

recharge patiern of the lake and relating these to the geologic history of the lake. Recharge of the surrounding aquifer by lake water occurs off shore in a narrow zone, as measured from lake–groundwater gradients. A 33-m-deep d18O profi le at the recharge side shows a lake d18O plume at depths...... that corroborates the interpretation of lake water recharging off shore and moving down gradient. Inclusion of lake bed heterogeneity in the model improved the comparison of simulated and observed discharge to the lake. The apparent age of the discharging groundwater to the lake was determined by CFCs, resulting...

Deep-water northern Gulf of Mexico hydrocarbon plays

International Nuclear Information System (INIS)

Peterson, R.H.; Cooke, D.W.

1995-01-01

The geologic setting in the deep-water (depths greater than 1,500 feet) Gulf of Mexico is very favorable for the existence of large, commercial hydrocarbon accumulations. These areas have active salt tectonics that create abundant traps, underlying mature Mesozoic source rocks that can be observed expelling oil and gas to the ocean surface, and good quality reservoirs provided by turbidite sand deposits. Despite the limited amount of drilling in the deep-water Gulf of Mexico, 11 deep-water accumulations have been discovered which, when developed, will rank in the top 100 largest fields in the Gulf of Mexico. Proved field discoveries (those with announced development plans) have added over 1 billion barrels of oil equivalent to Gulf of Mexico reserves, and unproved field discoveries may add to additional billion barrels of oil equivalent. The Minerals Management Service, United States Department of the Interior, has completed a gulf-wide review of over 1,086 oil and gas fields and placed every pay sand in each field into a hydrocarbon play (plays are defined by chronostratigraphy, lithostratigraph, structure, and production). Seven productive hydrocarbon plays were identified in the deep-water northern Gulf of Mexico. Regional maps illustrate the productive limits of each play. In addition, field data, dry holes, and wells with sub-economic pay were added to define the facies and structural limits for each play. Areas for exploration potential are identified for each hydrocarbon play. A type field for each play is chosen to demonstrate the play's characteristics

The Gulf of Mexico research initiative: It takes a village

Science.gov (United States)

Colwell, Rita R.

2016-07-01

The Gulf of Mexico Research Initiative (GoMRI) was established at the time of one of the most significant ecological events in recent memory, the Deepwater Horizon oil spill. Defined by the discharge of over 150 million gallons of crude oil and the introduction of over 1.8 million gallons of chemical dispersants into the Gulf system, the impacts of the Deepwater Horizon disaster reached the Gulf Coast's wetlands and beaches and impacted the surface and deep ocean. The ecological story of the event reveals a strong linkage between the deep sea research community and research priorities in the Gulf of Mexico (coastal processes, human health, etc.). Deep Sea research efforts have revealed critical parts of the story, providing information on transport, fate, and effects of the Deepwater Horizon oil release and subsequent recovery of the Gulf of Mexico ecosystems.

Gulf War Syndrome: a review of current knowledge and understanding.

Science.gov (United States)

Minshall, D

2014-01-01

The 1991 Persian Gulf War was a resounding military success for coalition forces, who liberated Kuwait following the Iraqi invasion. The medical legacy we have from the conflict is the poorly understood, yet remarkable, phenomenon of Gulf War Syndrome, which surfaced soon after. Epidemiological research has proven beyond doubt that Gulf War veterans report a wide variety of symptoms, in excess of appropriately matched control subjects, and experience worse general health. Numerous toxic environmental hazards have been suggested as causes of Gulf War Syndrome, yet exhaustive scientific study has failed to provide conclusive proof of any link. No novel or recognised disease has been found to account for the symptomatic burden of veterans, and the optimal treatment remains uncertain. This understanding can be added to from an anthropological perspective, where the narratives of those afflicted provide further insight. The nature of military life was changing at the time of the Gulf War, challenging the identity and beliefs of some veterans and causing socio-cultural distress. The symptomatic presentation of Gulf War Syndrome can be considered an articulation of this disharmony. Gulf War Syndrome can also be considered within the group of post-combat disorders such as shellshock, the like of which have occurred after major wars in the last century. With the current withdrawal from Afghanistan, the Defence Medical Services (DMS) should heed the lessons of history.

Bacterioplankton Community Dynamics and Nutrient Availability in a Shallow Well Mixed Estuary of the Northern Gulf of Mexico.

Science.gov (United States)

Hoch, M. P.

2016-02-01

Sabine Lake Estuary is a shallow, well mixed, tidal lagoon of the Northern Gulf of Mexico. This study defines the bacterioplankton community composition and factors that may influence its variation in Sabine Lake Estuary. Twenty physicochemical parameters, phytoplankton photopigments, and bacterial 16SrDNA sequences were analyzed seasonally from twelve sites ranging from the inflows of Sabine and Neches Rivers to the Sabine Pass outflow. Photopigments were used to estimate phytoplankton groups via CHEMTAX, and bacterioplankton 16SrDNA sequences of 97% similarity were quantified and taxa identified. Nutrient availability experiments were conducted on bacterioplankton. Notable seasonal differences were seen in six of the ten most common (>3% of total sequences) classes of bacterioplankton. Canonical correspondence analysis (CCA) of common classes was used to explore physiochemical parameters and phytoplankton groups influencing variation in the bacterioplankton. Alphaproteobacteria were most abundant throughout the year. Opitutae, Actinobacteria, Sphingobacteria, and Beta-proteobacteria were strongly influenced by conditions with higher TDN, DOC, turbidity, and Chlorophytes during winter when high river discharges reduced salinity. Planctomycetacia were most prevalent during spring and coincide with predominance of Cryptophytes. In summer and fall the aforementioned classes decline, and there is an increase in Synechococcophycideae. Nitrogen was least available to bacterioplankton during summer and fall. Clearer, warmer and more saline conditions with lower DOC reflect tidal movement of seawater into the estuary when river discharges were low, conditions favorable for Synechococcophycidea. Seasonal fluctuations in physicochemical conditions and certain phytoplankton groups influence the variation in the bacterioplankton community in Sabine Lake Estuary.

Crust and mantle of the gulf of Mexico

Science.gov (United States)

Moore, G.W.

1972-01-01

A SEEMING paradox has puzzled investigators of the crustal structure of the Gulf of Mexico since Ewing et al.1 calculated that a unit area of the rather thick crust in the gulf contains less mass than does a combination of the crust and enough of the upper mantle to make a comparable thickness in the Atlantic Ocean. They also noted that the free-air gravity of the gulf is essentially normal and fails by a large factor to be low enough to reflect the mass difference that they calculated. We propose a solution to this problem. ?? 1972 Nature Publishing Group.

77 FR 41376 - Gulf of Mexico Fishery Management Council; Public Meetings

Science.gov (United States)

2012-07-13

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration Gulf of Mexico Fishery... Internet. Please go to the Gulf of Mexico Fishery Management Council's Web site at www.gulfcouncil.org for instructions. Council address: Gulf of Mexico Fishery Management Council, 2203 N. Lois Avenue, Suite 1100...

78 FR 33070 - Gulf of Mexico Fishery Management Council; Public Meetings

Science.gov (United States)

2013-06-03

.... SUMMARY: The Gulf of Mexico Fishery Management Council (Council) will convene a public meeting. DATES: The...; telephone: (850) 433-3336. Council address: Gulf of Mexico Fishery Management Council, 2203 North Lois... Director, Gulf of Mexico Fishery Management Council; telephone: (813) 348-1630. SUPPLEMENTARY INFORMATION...

76 FR 22345 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Reef Fish Fishery of the Gulf of...

Science.gov (United States)

2011-04-21

... effective January 1, 2011, and implement interim measures to reduce overfishing of gag in the Gulf of Mexico... effect of this proposed rule is to reduce overfishing of the gag resource in the Gulf. DATES: Written... to prevent overfishing and achieve, on a continuing basis, the optimum yield (OY) from federally...

75 FR 2469 - Fisheries of the Caribbean, Gulf of Mexico, and South Atlantic; Reef Fish Fishery of the Gulf of...

Science.gov (United States)

2010-01-15

.... SUMMARY: NMFS issues this proposed rule to implement Amendment 31 to the Fishery Management Plan for the Reef Fish Resources of the Gulf of Mexico (FMP) prepared by the Gulf of Mexico Fishery Management... proposed rule is to balance the continued operation of the bottom longline component of the reef fish...

Aquatic macrophyte richness in Danish lakes in relation to alkalinity, transparency, and lake area

DEFF Research Database (Denmark)

Vestergaard, Ole Skafte; Sand-Jensen, Kaj

2000-01-01

We examined the relationship between environmental factors and the richness of submerged macrophytes species in 73 Danish lakes, which are mainly small, shallow, and have mesotrophic to hypertrophic conditions. We found that mean species richness per lake was only 4.5 in acid lakes of low...... alkalinity but 12.3 in lakes of high alkalinity due to a greater occurrence of the species-rich group of elodeids. Mean species richness per lake also increased significantly with increasing Secchi depth. No significant relationship between species richness and lake surface area was observed among the entire...... group of lakes or a subset of eutrophic lakes, as the growth of submerged macrophytes in large lakes may be restricted by wave action in shallow water and light restriction in deep water. In contrast, macrophyte species richness increased with lake surface area in transparent lakes, presumably due...

Keeping Safe Online: Perceptions of Gulf Adolescents

Science.gov (United States)

Alqahtani, Abdulmagni Mohammed

2016-01-01

With an increasing number of young people across the Gulf States now having access to the internet, the online safety of these adolescents is of concern. In a survey of 115 adolescents from the Gulf States, it was found that, although there are many benefits to young people, the risks of online usage are not fully understood by teenagers or their…

Oil and politics: the post-war Gulf

International Nuclear Information System (INIS)

Stevens, P.

1992-01-01

This report considers the path of international crude oil prices for the remainder of the decade. The report intends to concentrate on the role of the main Gulf oil producing states. Specifically, it seeks to consider the impact of the Iraqi invasion of Kuwait and its aftermath on the Gulf's role in the oil price equation. The report begins by developing an analytical framework which allows the relevant driving forces to be placed in context. From this framework, three issues will emerge central to the Gulf's role in the determination of oil prices: the size and distribution of any excess capacity to produce crude oil; the pricing objectives of those who control that excess capacity; and finally the cohesion of those who control the excess capacity. (author)

LakeMIP Kivu: evaluating the representation of a large, deep tropical lake by a set of one-dimensional lake models

Directory of Open Access Journals (Sweden)

WIM Thiery

2014-02-01

Full Text Available The African great lakes are of utmost importance for the local economy (fishing, as well as being essential to the survival of the local people. During the past decades, these lakes experienced fast changes in ecosystem structure and functioning, and their future evolution is a major concern. In this study, for the first time a set of one-dimensional lake models are evaluated for Lake Kivu (2.28°S; 28.98°E, East Africa. The unique limnology of this meromictic lake, with the importance of salinity and subsurface springs in a tropical high-altitude climate, presents a worthy challenge to the seven models involved in the Lake Model Intercomparison Project (LakeMIP. Meteorological observations from two automatic weather stations are used to drive the models, whereas a unique dataset, containing over 150 temperature profiles recorded since 2002, is used to assess the model's performance. Simulations are performed over the freshwater layer only (60 m and over the average lake depth (240 m, since salinity increases with depth below 60 m in Lake Kivu and some lake models do not account for the influence of salinity upon lake stratification. All models are able to reproduce the mixing seasonality in Lake Kivu, as well as the magnitude and seasonal cycle of the lake enthalpy change. Differences between the models can be ascribed to variations in the treatment of the radiative forcing and the computation of the turbulent heat fluxes. Fluctuations in wind velocity and solar radiation explain inter-annual variability of observed water column temperatures. The good agreement between the deep simulations and the observed meromictic stratification also shows that a subset of models is able to account for the salinity- and geothermal-induced effects upon deep-water stratification. Finally, based on the strengths and weaknesses discerned in this study, an informed choice of a one-dimensional lake model for a given research purpose becomes possible.

78 FR 9888 - Gulf of Mexico Fishery Management Council; Public Meeting

Science.gov (United States)

2013-02-12

.... SUMMARY: The Gulf of Mexico Fishery Management Council will convene a meeting of the Ad Hoc Artificial... Thursday, February 28, 2013. ADDRESSES: The meeting will be held at the Gulf of Mexico Fishery Management... INFORMATION CONTACT: Dr. John Froeschke, Fishery Biologist- Statistician; Gulf of Mexico Fishery Management...

78 FR 9372 - Gulf of Mexico Fishery Management Council; Public Meeting

Science.gov (United States)

2013-02-08

.... SUMMARY: The Gulf of Mexico Fishery Management Council will convene a meeting of the Ad Hoc Private.... on Tuesday, February 26, 2013. ADDRESSES: The meeting will be held at the Gulf of Mexico Fishery... INFORMATION CONTACT: Dr. John Froeschke, Fishery Biologist- Statistician; Gulf of Mexico Fishery Management...

78 FR 42755 - Gulf of Mexico Fishery Management Council; Public Hearings

Science.gov (United States)

2013-07-17

...: The Gulf of Mexico Fishery Management Council (Council) will hold public hearings for Coastal... through Friday August 15, 2013 at ten locations throughout the Gulf of Mexico. The public hearings will...; Mobile, AL; Corpus Christi and Texas City, TX. Council address: Gulf of Mexico Fishery Management Council...

Hurricane slams gulf operations

International Nuclear Information System (INIS)

Anon.

1992-01-01

This paper reports that reports of damage by Hurricane Andrew escalated last week as operators stepped up inspections of oil and gas installations in the Gulf of Mexico. By midweek, companies operating in the gulf and South Louisiana were beginning to agree that earlier assessments of damage only scratched the surface. Damage reports included scores of lost, toppled, or crippled platforms, pipeline ruptures, and oil slicks. By midweek the U.S. coast Guard had received reports of 79 oil spills. Even platforms capable of resuming production in some instances were begin curtailed because of damaged pipelines. Offshore service companies the another 2-4 weeks could be needed to fully assess Andrew's wrath. Lack of personnel and equipment was slowing damage assessment and repair

Zubarah, the Gulf and local and international trade

DEFF Research Database (Denmark)

Simonsen, Jørgen Bæk

2014-01-01

The deeply etched tracks of human achievement in the Gulf region since prehistory reflect a dynamic interplay between local, neighbouring and inter-regional agencies. Geography, resources, the exchange of commodities and the transfer of ideas elevated the status of the Gulf to that of a major...

Marine modification of terrestrial influences on Gulf hypoxia: Part II

Directory of Open Access Journals (Sweden)

2007-01-01

Full Text Available This study examines potential marine modification of two classes of terrestrial influence on Gulf hypoxia: (1 the flow of nutrient-rich water from the Mississippi/Atchafalaya River Basin and (2 the massive physical, hydrological, chemical and biological change associated with the Atchafalaya’s partial capture of the Mississippi River. The latter involves repartitioning of a total flow of about 20 000 m3 sec−1, equal to that of 13 Nile Rivers, and a sediment load of 210 million metric tonnes yr−1,nearly 20 times that delivered by all of the rivers of the East Coast of the USA. Also involved is the loss of hundreds-to-thousands of years of stored nutrients and organic matter to the Gulf from enormous coastal wetland loss. This study found that the oceanography of the Gulf minimises the impact of both classes of terrestrial influence from the Mississippi River and its nearby estuaries on Gulf hypoxia. Oceanographic conditions give events associated with the Atchafalaya River a disproportionately large influence on Gulf hypoxia. A truly holistic environmental approach which includes the full effects of this highly dynamic coastal area is recommended to better understand and control Gulf hypoxia.

Petroleum service projects in the Gulf of Guinea

Science.gov (United States)

Ken-Worgu, Kenneth Chukwumeka

2011-07-01

The goal of this record of study is to examine the major facets involved in managing several petroleum service projects located in three different countries in the Gulf of Guinea simultaneously, while effectively engaging in business development activities for the Oil and Industrial Services Group (OIS). This work also furnishes adequate background on related subject matters to enable understanding of the projects presented. The petroleum services sector is the back bone of the oil and gas industry. Services companies are vital to the success of all petroleum and energy producers in the USA, the Gulf of Guinea and the world. There is a need and demand for these service companies because they play various roles such as logistics, drilling, construction, dredging, pipe laying, procurement, food supply, human resource supply, etc. The Gulf of Guinea comprises of countries from west and central Africa. This project was limited to Nigeria, Equatorial Guinea and Cameroon. This area holds the largest petroleum reserves in Africa and plays a vital role in the global supply of petroleum. The Oil and Industrial Services Group (OIS), plans to establish herself as one of the leading petroleum service companies in this gulf. To manage this expansion, I have taken the role of Gulf of Guinea manager to apply my background as a petroleum engineer as well as my business skills to build a successful division of the company. This work provides a record of study of the management of services, projects and contracts carried out by the OIS group in the gulf of Guinea. The following are the specific projects in the Gulf of Guinea that I participated in: Managing delivering, maintenance and marketing of offshore vessels, Offshore pipe laying project, Integrated pipeline maintenance project, Development a petroleum technical training facilities, Agbami pipe insulation project, Engineering lift project and Capital budgeting analysis for potential investments. The details of the specific

Definition of Greater Gulf Basin Lower Cretaceous and Upper Cretaceous Lower Cenomanian Shale Gas Assessment Unit, United States Gulf of Mexico Basin Onshore and State Waters

Science.gov (United States)

Dennen, Kristin O.; Hackley, Paul C.

2012-01-01

An assessment unit (AU) for undiscovered continuous “shale” gas in Lower Cretaceous (Aptian and Albian) and basal Upper Cretaceous (lower Cenomanian) rocks in the USA onshore Gulf of Mexico coastal plain recently was defined by the U.S. Geological Survey (USGS). The AU is part of the Upper Jurassic-Cretaceous-Tertiary Composite Total Petroleum System (TPS) of the Gulf of Mexico Basin. Definition of the AU was conducted as part of the 2010 USGS assessment of undiscovered hydrocarbon resources in Gulf Coast Mesozoic stratigraphic intervals. The purpose of defining the Greater Gulf Basin Lower Cretaceous Shale Gas AU was to propose a hypothetical AU in the Cretaceous part of the Gulf Coast TPS in which there might be continuous “shale” gas, but the AU was not quantitatively assessed by the USGS in 2010.

Last millennium sedimentation in the Gulf of Cariaco (NE Venezuela): Evidence for morphological changes of gulf entrance and possible relations with large earthquakes

Science.gov (United States)

Aguilar, Iliana; Beck, Christian; Audemard, Franck; Develle, Anne-Lise; Boussafir, Mohammed; Campos, Corina; Crouzet, Christian

2016-01-01

The Cariaco Basin and the Gulf of Cariaco in Venezuela are two major basins along the seismogenic El Pilar right lateral fault, among which the Cariaco Basin is a pull-apart. Both basins are sites of anoxia and organic-rich deposits. To examine whether the sediments in the Gulf of Cariaco have recorded traces of historical or prehistorical earthquakes, we extracted and analyzed twelve 1 m-long gravity cores, sampling the last millennium sedimentation. We focused on analyzing the sediment sources with different techniques (particle size analysis, XRF, loss on ignition tests, magnetic properties, Rock-Eval pyrolysis, 14C dating). The results confirm that major upwelling occurs at the western gulf entrance and makes deep water flowing from the Cariaco Basin into the Gulf of Cariaco. These flows carry an organic-rich suspended load. Furthermore, we found evidence of a particular, widespread fine-grained siliciclastic deposit (named SiCL3) within the gulf, whose age suggests that it likely formed during the large 1853 AD earthquake that stroke the Cumaná city. We suggest that the earthquake-induced large submarine landslides that modified the topography of the gulf's entrance, which in turn promoted upwelling and open marine water flows from the Cariaco Basin. The layer SiCL3 would be the sediment load remobilized during this chain of events.

Methane emissions from permafrost thaw lakes limited by lake drainage.

NARCIS (Netherlands)

van Huissteden, J.; Berrittella, C.; Parmentier, F.J.W.; Mi, Y.; Maximov, T.C.; Dolman, A.J.

2011-01-01

Thaw lakes in permafrost areas are sources of the strong greenhouse gas methane. They develop mostly in sedimentary lowlands with permafrost and a high excess ground ice volume, resulting in large areas covered with lakes and drained thaw-lake basins (DTLBs; refs,). Their expansion is enhanced by

75 FR 7444 - Gulf of Mexico Fishery Management Council; Public Meeting

Science.gov (United States)

2010-02-19

.... SUMMARY: The Gulf of Mexico Fishery Management Council (Council) will convene a web based meeting of the... via internet. Please go to the Gulf of Mexico Fishery Management Council's website at www.gulfcouncil.org for instructions. Council address: Gulf of Mexico Fishery Management Council, 2203 N. Lois Avenue...

Energy partnership: China and the Gulf states

International Nuclear Information System (INIS)

Bahgat, G.

2005-01-01

One of the most significant developments in the global energy market in the last several years has been China's skyrocketing demand for energy. In 1993, China became a net oil importer for the first time in its history and in 2003 replaced Japan as the world's second-largest oil importer (after the United States). The country needs more energy to maintain its spectacular economic performance. This study examines China's attempts to satisfy its growing needs for oil and natural gas by increasing imports from Russia and Central Asia/Caspian Sea region. The analysis suggests that despite growing cooperation between the two sides, the Gulf region is likely to satisfy most of China's hydrocarbons needs. Energy partnership between China and the Gulf has already started and is likely to be consolidated over the next few decades. The study also argues that this growing partnership between China and the Gulf should not be seen as a threat to any third party. The global energy market is well-integrated. Energy policy should not be seen in zero-sum terms. A China-Gulf partnership will benefit both sides and contribute to the stability of global energy markets. (author)

The Gulf War Nuclear, Biological, and Chemical Lessons Learned

National Research Council Canada - National Science Library

Ugone, Mary

2001-01-01

This audit was requested by the Office of the Special Assistant for Gulf War Illnesses, Medical Readiness and Military Deployments, which has the authority to coordinate all aspects of Gulf War investigations for DoD...

Great Lakes Bathymetry

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lakes Michigan, Erie, Saint Clair, Ontario and Huron has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and...

Lake and lake-related drainage area parameters for site investigation program

Energy Technology Data Exchange (ETDEWEB)

Blomqvist, P.; Brunberg, A.K. [Uppsala Univ. (Sweden). Dept. of Limnology; Brydsten, L [Umeaa Univ. (Sweden). Dept. of Ecology and Environmental Science

2000-09-01

In this paper, a number of parameters of importance to a preliminary determination of the ecological function of lakes are presented. The choice of parameters have been made with respect to a model for the determination of the nature conservation values of lakes which is currently being developed by the authors of this report, but is also well suited for a general description of the lake type and the functioning of the inherent ecosystem. The parameters have been divided into five groups: (1) The location of the object relative important gradients in the surrounding nature; (2) The lake catchment area and its major constituents; (3) The lake morphometry; (4) The lake ecosystem; (5) Human-induced damages to the lake ecosystem. The first two groups, principally based on the climate, hydrology, geology and vegetation of the catchment area represent parameters that can be used to establish the rarity and representativity of the lake, and will in the context of site investigation program be used as a basis for generalisation of the results. The third group, the lake morphometry parameters, are standard parameters for the outline of sampling programmes and for calculations of the physical extension of different key habitats in the system. The fourth group, the ecosystem of the lake, includes physical, chemical and biological parameters required for determination of the stratification pattern, light climate, influence from the terrestrial ecosystem of the catchment area, trophic status, distribution of key habitats, and presence of fish and rare fauna and flora in the lake. In the context of site investigation program, the parameters in these two groups will be used for budget calculations of the flow of energy and material in the system. The fifth group, finally, describes the degree on anthropogenic influence on the ecosystem and will in the context of site investigation programmes be used to judge eventual malfunctioning within the entire, or parts of, the lake

Lake and lake-related drainage area parameters for site investigation program

International Nuclear Information System (INIS)

Blomqvist, P.; Brunberg, A.K.; Brydsten, L

2000-09-01

In this paper, a number of parameters of importance to a preliminary determination of the ecological function of lakes are presented. The choice of parameters have been made with respect to a model for the determination of the nature conservation values of lakes which is currently being developed by the authors of this report, but is also well suited for a general description of the lake type and the functioning of the inherent ecosystem. The parameters have been divided into five groups: 1) The location of the object relative important gradients in the surrounding nature; 2) The lake catchment area and its major constituents; 3) The lake morphometry; 4) The lake ecosystem; 5) Human-induced damages to the lake ecosystem. The first two groups, principally based on the climate, hydrology, geology and vegetation of the catchment area represent parameters that can be used to establish the rarity and representativity of the lake, and will in the context of site investigation program be used as a basis for generalisation of the results. The third group, the lake morphometry parameters, are standard parameters for the outline of sampling programmes and for calculations of the physical extension of different key habitats in the system. The fourth group, the ecosystem of the lake, includes physical, chemical and biological parameters required for determination of the stratification pattern, light climate, influence from the terrestrial ecosystem of the catchment area, trophic status, distribution of key habitats, and presence of fish and rare fauna and flora in the lake. In the context of site investigation program, the parameters in these two groups will be used for budget calculations of the flow of energy and material in the system. The fifth group, finally, describes the degree on anthropogenic influence on the ecosystem and will in the context of site investigation programmes be used to judge eventual malfunctioning within the entire, or parts of, the lake ecosystem

Astronaut observations of the Persian (Arabian) Gulf during STS-45

Science.gov (United States)

Ackleson, Steven G.; Pitts, David E.; Sullivan, Kathryn D.; Reynolds, R. M.

1992-01-01

As a result of the 1991 Persian Gulf war, between mid-January and June 1991, the Persian Gulf was contaminated with an estimated 4 to 6 million barrels of crude oil, released directly into the Gulf from refinement facilities, transhipment terminals, and moored tankers along the coast of Kuwait, and precipitated from oil fire smoke plumes. To assess the environmental impact of the oil, an international team of marine scientists representing 14 nations was assembled under the auspices of the United Nations International Oceanic Commission and the Regional Organization for Protection of the Marine Environment to conduct detailed surveys of the Persian Gulf, the Strait of Hormuz, and the Gulf of Oman, including hydrographic, chemical, and biological measurements. To supplement the field surveys and to serve as an aid in data interpretation, astronauts aboard the Space Shuttle Atlantis photographed water features and coastal habitats in the Persian Gulf during mission STS-45 (24 March to 02 April 1992). The astronauts collected 111 hand-held, color photographs of the Gulf (72 70-mm photographs and 39 5-inch photographs) from an altitude of 296 km (160 n.mi.). The photographs reveal distributions in water turbidity associated with outflow from the Shatt-al-Arab and water circulation along the entire coast of Iran and the Strait of Hormuz, coastal wetlands and shallow-water habitats, and sticks appearing in the sunglint pattern, which appear to be oil.

78 FR 14980 - Gulf of Mexico Fishery Management Council; Public Meetings

Science.gov (United States)

2013-03-08

.... SUMMARY: The Gulf of Mexico Fishery Management Council will convene scoping meetings to discuss a For-Hire... through April 3, 2013 at eight locations throughout the Gulf of Mexico. The scoping meetings will begin at..., TX. Council address: Gulf of Mexico Fishery Management Council, 2203 N. Lois Avenue, Suite 1100...

The Gulf Security Dialogue and Related Arms Sale Proposals

National Research Council Canada - National Science Library

Blanchard, Christopher M; Grimmett, Richard F

2008-01-01

...) security cooperation under the auspices of a new Gulf Security Dialogue (GSD). The Dialogue now serves as the principal security coordination mechanism between the United States and the six countries of the Gulf Cooperation Council (GCC...

Rubidium-strontium ages from the Oxford Lake-Knee Lake greenstone belt, northern Manitoba

International Nuclear Information System (INIS)

Clark, G.S.; Cheung, S.-P.

1980-01-01

Rb-Sr whole-rock ages have been determined for rocks from the Oxford Lake-Knee Lake-Gods Lake geenstone belt in the Superior Province of northeastern Manitoba. The age of the Magill Lake Pluton is 2455 +- 35 Ma(lambda 87 Rb = 1.42 x 10 -11 yr -1 ), with an initial 87 Sr/ 86 Sr ratio of 0.7078 +- 0.0043. This granite stock intrudes the Oxford Lake Group, so it is post-tectonic and probably related to the second, weaker stage of metamorphism. The age of the Bayly Lake Pluton is 2424 +- 74 Ma, with an initial 87 Sr/ 86 Sr ratio of 0.7029 +- 0.0001. This granodioritic batholith complex does not intrude the Oxford Lake Group. It is syn-tectonic and metamorphosed. The age of volcanic rocks of the Hayes River Group, from Goose Lake (30 km south of Gods Lake Narrows), is 2680 +- 125 Ma, with an initial 87 Sr/ 86 Sr ratio of 0.7014 +- 0.0009. The age for the Magill Lake and Bayly Lake Plutons can be interpreted as the minimum ages of granite intrusion in the area. The age for the Hayes River Group volcanic rocks is consistent with Rb-Sr ages of volcanic rocks from other Archean greenstone belts within the northwestern Superior Province. (auth)

Surface faults in the gulf coastal plain between Victoria and Beaumont, Texas

Science.gov (United States)

Verbeek, Earl R.

1979-01-01

Displacement of the land surface by faulting is widespread in the Houston-Galveston region, an area which has undergone moderate to severe land subsidence associated with fluid withdrawal (principally water, and to a lesser extent, oil and gas). A causative link between subsidence and fluid extraction has been convincingly reported in the published literature. However, the degree to which fluid withdrawal affects fault movement in the Texas Gulf Coast, and the mechanism(s) by which this occurs are as yet unclear. Faults that offset the ground surface are not confined to the large (>6000-km2) subsidence “bowl” centered on Houston, but rather are common and characteristic features of Gulf Coast geology. Current observations and conclusions concerning surface faults mapped in a 35,000-km2 area between Victoria and Beaumont, Texas (which area includes the Houston subsidence bowl) may be summarized as follows: (1) Hundreds of faults cutting the Pleistocene and Holocene sediments exposed in the coastal plain have been mapped. Many faults lie well outside the Houston-Galveston region; of these, more than 10% are active, as shown by such features as displaced, fractured, and patched road surfaces, structural failure of buildings astride faults, and deformed railroad tracks. (2) Complex patterns of surface faults are common above salt domes. Both radial patterns (for example, in High Island, Blue Ridge, Clam Lake, and Clinton domes) and crestal grabens (for example, in the South Houston and Friendswood-Webster domes) have been recognized. Elongate grabens connecting several known and suspected salt domes, such as the fault zone connecting Mykawa, Friendswood-Webster, and Clear Lake domes, suggest fault development above rising salt ridges. (3) Surface faults associated with salt domes tend to be short (10 km), occur singly or in simple grabens, have gently sinuous traces, and tend to lie roughly parallel to the ENE-NE “coastwise” trend common to regional growth

The deepwater Gulf of Mexico : promises delivered?

International Nuclear Information System (INIS)

Pickering, D.R.

1999-01-01

A summary review of deepwater Gulf of Mexico (GOM) oil production was presented for the years 1989 to 1998. Trends and prospects in deepwater GOM production and leasing were assessed. Promises and forecasts made in the early 1990s were compared with what actually happened since then. Forecasts in the early 1990s promised deeper, faster and cheaper developments in the deepwater Gulf. Results of the comparison showed that the prognosticators were correct on all three counts. Regarding the future of the Gulf, one can be justified in being optimistic in so far as more experience, robust economics, more and cheaper rigs can be taken as reliable indicators of optimism. In contrast, there are certain negatives to consider, such as low commodity prices, budget constraints, lease expirations, technical challenges and increased competition. . 12 figs

Pollution in the Gulf: Monitoring the marine environment

International Nuclear Information System (INIS)

Fowler, S.W.

1993-01-01

More than 2 years after the Gulf conflict, scientists are continuing to keep a close watch on marine pollution stemming from the war. Following the conflict in early 1991, major concern was raised worldwide when an estimated four to eight million barrels of crude oil were directly released into the Persian Gulf from the Sea Island terminal in Kuwait. Such amounts clearly made it the largest oil spill in history. The catastrophe was exacerbated when Kuwaiti oil fields were ignited. The magnitude of the pollution, and the types of toxic contaminants involved, led to a worldwide response through the United Nations system. An inter-agency plan of action was developed quickly. As one of its steps, the co-ordinating agency - the United Nations Environment Programme (UNEP) - asked the IAEA's Marine Environment Laboratory (MEL) in Monaco to help make a preliminary assessment of the situation. The Laboratory's main goal in initial surveys was to map the extent and general degree of the war-related pollution throughout the Gulf. Since the initial surveys were done, IAEA-MEL scientists have been engaged in regional follow-up activities in ongoing attempts to obtain a clearer picture of the oil pollution's effects on the Gulf's marine environment. This article highlights the laboratory's work in the Gulf following the 1991 conflict, within the context of co-operative programmes and projects. 1 fig

A Dynamical Downscaling study over the Great Lakes Region Using WRF-Lake: Historical Simulation

Science.gov (United States)

Xiao, C.; Lofgren, B. M.

2014-12-01

As the largest group of fresh water bodies on Earth, the Laurentian Great Lakes have significant influence on local and regional weather and climate through their unique physical features compared with the surrounding land. Due to the limited spatial resolution and computational efficiency of general circulation models (GCMs), the Great Lakes are geometrically ignored or idealized into several grid cells in GCMs. Thus, the nested regional climate modeling (RCM) technique, known as dynamical downscaling, serves as a feasible solution to fill the gap. The latest Weather Research and Forecasting model (WRF) is employed to dynamically downscale the historical simulation produced by the Geophysical Fluid Dynamics Laboratory-Coupled Model (GFDL-CM3) from 1970-2005. An updated lake scheme originated from the Community Land Model is implemented in the latest WRF version 3.6. It is a one-dimensional mass and energy balance scheme with 20-25 model layers, including up to 5 snow layers on the lake ice, 10 water layers, and 10 soil layers on the lake bottom. The lake scheme is used with actual lake points and lake depth. The preliminary results show that WRF-Lake model, with a fine horizontal resolution and realistic lake representation, provides significantly improved hydroclimates, in terms of lake surface temperature, annual cycle of precipitation, ice content, and lake-effect snowfall. Those improvements suggest that better resolution of the lakes and the mesoscale process of lake-atmosphere interaction are crucial to understanding the climate and climate change in the Great Lakes region.

[Characterizing chromophoric dissolved organic matter (CDOM) in Lake Honghu, Lake Donghu and Lake Liangzihu using excitation-emission matrices (EEMs) fluorescence and parallel factor analysis (PARAFAC)].

Science.gov (United States)

Zhou, Yong-Qiang; Zhang, Yun-Lin; Niu, Cheng; Wang, Ming-Zhu

2013-12-01

Little is known about DOM characteristics in medium to large sized lakes located in the middle and lower reaches of Yangtze River, like Lake Honghu, Lake Donghu and Lake Liangzihu. Absorption, fluorescence and composition characteristics of chromophoric dissolved organic matter (CDOM) are presented using the absorption spectroscopy, the excitation-emission ma trices (EEMs) fluorescence and parallel factor analysis (PARAFAC) model based on the data collected in Sep-Oct. 2007 including 15, 9 and 10 samplings in Lake Honghu, Lake Donghu and Lake Liangzihu, respectively. CDOM absorption coefficient at 350 nm a(350) coefficient in Lake Honghu was significantly higher than those in Lake Donghu and Lake Liangzihu (t-test, pCDOM spectral slope in the wavelength range of 280-500 nm (S280-500) and a(350) (R2 =0. 781, p<0. 001). The mean value of S280-500 in Lake Honghu was significantly lower than those in Lake Donghu (t-test, pLake Liangzihu (t-test, p<0. 001). The mean value of spectral slope ratio SR in Lake Honghu was also significantly lower than those in Lake Donghu and Lake Liangzihu (t-test, p<0. 05). Two humic-like (C1, C2) and two protein-like fluorescent components (C3, C4) were identified by PARAFAC model, among which significant positive correlations were found between C1 and C2 (R2 =0. 884, p<0. 001), C3 and C4 (R2 =0. 677, p<0.001), respectively, suggesting that the sources of the two humic-like components as well as the two protein-like components were similar. However, no significant correlation has been found between those 4 fluorescent components and DOC concentration. Th e fluorescenceindices of FI255 (HIX), Fl265, FI310 (BIX) and Fl370 in Lake Donghu were all significantly higher than those in Lake Liangzihu (t-test, p <0.05) and Lake Honghu (t-test, p<0. 01), indicating that the eutrophication status in Lake Donghu was higher than Lake Honghu and Lake Liangzihu.

DNA barcoding and morphological studies confirm the occurrence of three Atarbolana (Crustacea: Isopoda: Cirolanidae) species along the coastal zone of the Persian Gulf and Gulf of Oman.

Science.gov (United States)

Khalaji-Pirbalouty, Valiallah; Raupach, Michael J

2016-11-27

Two species of Atarbolana (Cirolanidae: Isopoda) from the intertidal zone of the Gulf of Oman and the Persian Gulf were studied and redescribed. The known distribution of this small genus is limited to the northern areas of the Indian Ocean, from the Pakistan coasts to the Persian Gulf. The analyses of DNA barcodes as well as detailed morphological studies clearly support the existence of three distinct Atarbolana species along the coastal zone of the Persian Gulf and northern Arabian Sea. Furthermore, A. dasycolus Yasmeen, 2004 is synonymized with A. setosa Javed and Yasmeen, 1989.

Arab Gulf States : recruitment of Asian workers

OpenAIRE

JUREIDINI, Ray

2014-01-01

GLMM - Gulf Labour Markets and Migration This paper addresses a neglected area in studies of migrant labor in the Gulf States showing that exploitation of migrant workers occurs before deployment. Evidence from interviews conducted in the five major labour sending countries to Qatar (Philippines, Nepal, Bangladesh, Sri Lanka, and India) suggests that the recruitment procedures and corrupt practices by recruitment agencies and employing company personnel in the receiving country place unski...

75 FR 62109 - Gulf of Mexico Fishery Management Council (Council); Public Meetings

Science.gov (United States)

2010-10-07

... meetings. SUMMARY: The Gulf of Mexico Fishery Management Council (GMFMC) will convene public meetings... Embassy Suites Hotel, 4914 Constitution Ave., Baton Rouge, LA 70808. Council address: Gulf of Mexico... CONTACT: Dr. Stephen Bortone, Executive Director, Gulf of Mexico Fishery Management Council; telephone...

77 FR 40859 - Gulf of Mexico Fishery Management Council; Public Meetings; Correction

Science.gov (United States)

2012-07-11

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration Gulf of Mexico Fishery.... SUMMARY: The Gulf of Mexico Fishery Management Council (Council) will convene its Law Enforcement Advisory... Ludwig Lane, Grand Isle, LA 70358; telephone: (985) 787-2163 Council address: Gulf of Mexico Fishery...

Deglaciation, lake levels, and meltwater discharge in the Lake Michigan basin

Science.gov (United States)

Colman, Steven M.; Clark, J.A.; Clayton, L.; Hansel, A.K.; Larsen, C.E.

1994-01-01

The deglacial history of the Lake Michigan basin, including discharge and routing of meltwater, is complex because of the interaction among (1) glacial retreats and re-advances in the basin (2) the timing of occupation and the isostatic adjustment of lake outlets and (3) the depositional and erosional processes that left evidence of past lake levels. In the southern part of the basin, a restricted area little affected by differential isostasy, new studies of onshore and offshore areas allow refinement of a lake-level history that has evolved over 100 years. Important new data include the recognition of two periods of influx of meltwater from Lake Agassiz into the basin and details of the highstands gleaned from sedimentological evidence. Major disagreements still persist concerning the exact timing and lake-level changes associated with the Algonquin phase, approximately 11,000 BP. A wide variety of independent data suggests that the Lake Michigan Lobe was thin, unstable, and subject to rapid advances and retreats. Consequently, lake-level changes were commonly abrupt and stable shorelines were short-lived. The long-held beliefs that the southern part of the basin was stable and separated from deformed northern areas by a hinge-line discontinuity are becoming difficult to maintain. Numerical modeling of the ice-earth system and empirical modeling of shoreline deformation are both consistent with observed shoreline tilting in the north and with the amount and pattern of modern deformation shown by lake-level gauges. New studies of subaerial lacustrine features suggest the presence of deformed shorelines higher than those originally ascribed to the supposed horizontal Glenwood level. Finally, the Lake Michigan region as a whole appears to behave in a similar manner to other areas, both local (other Great Lakes) and regional (U.S. east coast), that have experienced major isostatic changes. Detailed sedimentological and dating studies of field sites and additional

The growth of coral reef science in the Gulf: a historical perspective.

Science.gov (United States)

Burt, John A

2013-07-30

Coral reef science has grown exponentially in recent decades in the Gulf. Analysis of literature from 1950 to 2012 identified 270 publications on coral reefs in the Gulf, half of which were published in just the past decade. This paper summarizes the growth and evolution of coral reef science in the Gulf by examining when, where and how research has been conducted on Gulf reefs, who conducted that research, and what themes and taxa have dominated scientific interest. The results demonstrate that there has been significant growth in our understanding of the valuable coral reefs of the Gulf, but also highlight the fact that we are documenting an increasingly degraded ecosystem. Reef scientists must make a concerted effort to improve dialogue with regional reef management and decision-makers if we are to stem the tide of decline in coral reefs in the Gulf. Copyright © 2013 Elsevier Ltd. All rights reserved.

Use of a Florida Gulf Coast Barrier Island by Spring Trans-Gulf Migrants and the Projected Effects of Sea Level Rise on Habitat Availability.

Directory of Open Access Journals (Sweden)

Lori A Lester

Full Text Available Barrier islands on the north coast of the Gulf of Mexico are an internationally important coastal resource. Each spring hundreds of thousands of Nearctic-Neotropical songbirds crossing the Gulf of Mexico during spring migration use these islands because they provide the first landfall for individuals following a trans-Gulf migratory route. The effects of climate change, particularly sea level rise, may negatively impact habitat availability for migrants on barrier islands. Our objectives were (1 to confirm the use of St. George Island, Florida by trans-Gulf migrants and (2 to determine whether forested stopover habitat will be available for migrants on St. George Island following sea level rise. We used avian transect data, geographic information systems, remote sensing, and simulation modelling to investigate the potential effects of three different sea level rise scenarios (0.28 m, 0.82 m, and 2 m on habitat availability for trans-Gulf migrants. We found considerable use of the island by spring trans-Gulf migrants. Migrants were most abundant in areas with low elevation, high canopy height, and high coverage of forests and scrub/shrub. A substantial percentage of forest (44% will be lost by 2100 assuming moderate sea level rise (0.82 m. Thus, as sea level rise progresses, less forests will be available for migrants during stopover. Many migratory bird species' populations are declining, and degradation of barrier island stopover habitat may further increase the cost of migration for many individuals. To preserve this coastal resource, conservation and wise management of migratory stopover areas, especially near ecological barriers like the Gulf of Mexico, will be essential as sea levels rise.

Use of a Florida Gulf Coast Barrier Island by Spring Trans-Gulf Migrants and the Projected Effects of Sea Level Rise on Habitat Availability.

Science.gov (United States)

Lester, Lori A; Gutierrez Ramirez, Mariamar; Kneidel, Alan H; Heckscher, Christopher M

2016-01-01

Barrier islands on the north coast of the Gulf of Mexico are an internationally important coastal resource. Each spring hundreds of thousands of Nearctic-Neotropical songbirds crossing the Gulf of Mexico during spring migration use these islands because they provide the first landfall for individuals following a trans-Gulf migratory route. The effects of climate change, particularly sea level rise, may negatively impact habitat availability for migrants on barrier islands. Our objectives were (1) to confirm the use of St. George Island, Florida by trans-Gulf migrants and (2) to determine whether forested stopover habitat will be available for migrants on St. George Island following sea level rise. We used avian transect data, geographic information systems, remote sensing, and simulation modelling to investigate the potential effects of three different sea level rise scenarios (0.28 m, 0.82 m, and 2 m) on habitat availability for trans-Gulf migrants. We found considerable use of the island by spring trans-Gulf migrants. Migrants were most abundant in areas with low elevation, high canopy height, and high coverage of forests and scrub/shrub. A substantial percentage of forest (44%) will be lost by 2100 assuming moderate sea level rise (0.82 m). Thus, as sea level rise progresses, less forests will be available for migrants during stopover. Many migratory bird species' populations are declining, and degradation of barrier island stopover habitat may further increase the cost of migration for many individuals. To preserve this coastal resource, conservation and wise management of migratory stopover areas, especially near ecological barriers like the Gulf of Mexico, will be essential as sea levels rise.

Military and Non Military Threats to the Gulf Cooperation Countries

National Research Council Canada - National Science Library

Al-Khulaifi, Hamad H

2008-01-01

The international strategic importance of Gulf oil resources, the intense political and economic attention to the Gulf Countries affairs by nations beyond the region, necessitate looking at the impact...

Mercury in contaminated coastal environments; a case study: the Gulf of Trieste.

Science.gov (United States)

Horvat, M; Covelli, S; Faganeli, J; Logar, M; Mandić, V; Rajar, R; Sirca, A; Zagar, D

1999-09-30

Some general facts, uncertainties and gaps in current knowledge of Hg cycling in coastal and oceanic environments are given. As a case study the Gulf of Trieste is chosen. The Gulf is subject to substantial Hg pollution, originating from the Soca river, that drains the cinnabar deposits of the world's second largest Hg mining area, Idrija, Slovenia. The Gulf belongs to one of the most polluted areas in the Mediterranean. Apart from Hg problems, the Gulf is also a subject to industrial and sewage pollution. Due to deteriorating water quality in the Gulf there is a great concern that Hg can be remobilized from sediments to the water column as well as enhance methylation rates which may consequently increase already elevated Hg levels in aquatic organisms. The paper presents data from a recent study which aims to assess the extent of contamination of the Gulf of Trieste after the closure of the Hg mine. Mercury and methylmercury were measured in various environmental compartments (estuarine and marine waters, sediments, and organisms) during the period 1995-1997. Data obtained show that even 10 years after closure of the Hg mine, Hg concentrations in river sediments and water are still very high and did not show the expected decrease of Hg in the Gulf of Trieste. A provisional annual mercury mass balance was established for the Gulf of Trieste showing that the major source of inorganic mercury is still the River Soca (Isonzo) while the major source of methylmercury is the bottom sediment of the Gulf.

Lakes, Lagerstaetten, and Evolution

Science.gov (United States)

Kordesch, E. G.; Park, L. E.

2001-12-01

The diversity of terrestrial systems is estimated to be greater than in the marine realm. However no hard data yet exists to substantiate this claim. Ancient lacustrine deposits may preserve an exceptionally diverse fossil fauna and aid in determining continental faunal diversities. Fossils preserved in lake deposits, especially those with exceptional preservation (i.e. Konservat Lagerstaetten), may represent a dependable method for determining species diversity changes in the terrestrial environment because of their faunal completeness. Important Konservat Lagerstaetten, such as the Green River Formation (US) and Messel (Germany), both Eocene in age, are found in lake sediments and show a remarkable faunal diversity for both vertebrates and invertebrates. To date information from nearly 25 lake lagerstaetten derived from different types of lake basins from the Carboniferous to the Miocene have been collected and described. Carboniferous sites derive from the cyclothems of Midcontinent of the US while many Cenozoic sites have been described from North and South America as well as Europe and Australia. Asian sites contain fossils from the Mesozoic and Cenozoic. With this data, insight into the evolutionary processes associated with lake systems can be examined. Do lakes act as unique evolutionary crucibles in contrast to marine systems? The speciation of cichlid fishes in present-day African lakes appears to be very high and is attributed to the diversity of environments found in large rift lakes. Is this true of all ancient lakes or just large rift lakes? The longevity of a lake system may be an important factor in allowing speciation and evolutionary processes to occur; marine systems are limited only in the existence of environments as controlled by tectonics and sea level changes, on the order of tens of millions of years. Rift lakes are normally the longest lived in the millions of years. Perhaps there are only certain types of lakes in which speciation of

Suspended-sediment budget, flow distribution, and lake circulation for the Fox Chain of Lakes in Lake and McHenry Counties, Illinois, 1997-99

Science.gov (United States)

Schrader, David L.; Holmes, Robert R.

2000-01-01

The Fox Chain of Lakes is a glacial lake system in McHenry and Lake Counties in northern Illinois and southern Wisconsin. Sedimentation and nutrient overloading have occurred in the lake system since the first dam was built (1907) in McHenry to raise water levels in the lake system. Using data collected from December 1, 1997, to June 1, 1999, suspended-sediment budgets were constructed for the most upstream lake in the system, Grass Lake, and for the lakes downstream from Grass Lake. A total of 64,900 tons of suspended sediment entered Grass Lake during the study, whereas a total of 70,600 tons of suspended sediment exited the lake, indicating a net scour of 5,700 tons of sediment. A total of 44,100 tons of suspended sediment was measured exiting the Fox Chain of Lakes at Johnsburg, whereas 85,600 tons entered the system downstream from Grass Lake. These suspended-sediment loads indicate a net deposition of 41,500 tons downstream from Grass Lake, which represents a trapping efficiency of 48.5 percent. A large amount of recreational boating takes place on the Fox Chain of Lakes during summer months, and suspended-sediment load was observed to rise from 110 tons per day to 339 tons per day during the 1999 Memorial Day weekend (May 26 ?31, 1999). Presumably, this rise was the result of the boating traffic because no other hydrologic event is known to have occurred that might have caused the rise. This study covers a relatively short period and may not represent the long-term processes of the Fox Chain of Lakes system, although the sediment transport was probably higher than an average year. The bed sediments found on the bottom of the lakes are composed of mainly fine particles in the silt-clay range. The Grass Lake sediments were characterized as black peat with an organic content of between 9 and 18 percent, and the median particle size ranged from 0.000811 to 0.0013976 inches. Other bed material samples were collected at streamflow-gaging stations on the

33 CFR 162.220 - Hoover Dam, Lake Mead, and Lake Mohave (Colorado River), Ariz.-Nev.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Hoover Dam, Lake Mead, and Lake... REGULATIONS § 162.220 Hoover Dam, Lake Mead, and Lake Mohave (Colorado River), Ariz.-Nev. (a) Lake Mead and... the axis of Hoover Dam and that portion of Lake Mohave (Colorado River) extending 4,500 feet...

Physical processes in the Gulf of Kachchh: A review

Digital Repository Service at National Institute of Oceanography (India)

Vethamony, P.; Babu, M.T.

A brief review of various physical processes acting in the Gulf of Kachchh (GoK), which have prominent roles in Gulf dynamics, is presented in this article. The eddies present in the GoK confirm that they are permanent features of the Go...

Carbon emissions from the Persian Gulf countries

International Nuclear Information System (INIS)

Al-Shatti, A.M.

1991-01-01

The wealth of indigenous oil resources has largely determined the economic and energy use patterns in the member countries of the Gulf Cooperation Council (GCC). Sizable profits accrued from the inflation of world oil prices spurred tremendous economic growth across the Gulf during the 1970s. The GCC nations channeled this oil wealth into the rapid development of infrastructure and the creation of super-welfare states. Today, these highly affluent societies enjoy benefits ranging from free medical care, schooling and housing to subsidized electricity and gasoline supplies. The combination of great personal prosperity, abundant petroleum resources and highly subsidized energy prices has led to excessive energy use in the Gulf nations. These countries consume among the highest amounts of energy per capita in the world. Correspondingly, these nations generate among the highest levels of energy-related carbon per capita

76 FR 37064 - Gulf of Mexico Fishery Management Council (Council); Public Meeting

Science.gov (United States)

2011-06-24

... meeting. SUMMARY: The Gulf of Mexico Fishery Management Council will convene a public meeting via webinar... meeting will be held via webinar. Council address: Gulf of Mexico Fishery Management Council, 2203 North... Executive Director, Gulf of Mexico Fishery Management Council; telephone: (813) 348-1630. SUPPLEMENTARY...

First evidence of successful natural reproduction by planted lake trout in Lake Huron

Science.gov (United States)

Nester, Robert T.; Poe, Thomas P.

1984-01-01

Twenty-two lake trout (Salvelinus namaycush) swim-up fry, 24-27 mm long, were captured with emergent fry traps and a tow net in northwestern Lake Huron on a small nearshore reef off Alpena, Michigan, between May 10 and June 1, 1982. These catches represent the first evidence of successful production of swim-up fry by planted, hatchery-reared lake trout in Lake Huron since the lake trout rehabilitation program began in 1973.

Estimation of lake water - groundwater interactions in meromictic mining lakes by modelling isotope signatures of lake water.

Science.gov (United States)

Seebach, Anne; Dietz, Severine; Lessmann, Dieter; Knoeller, Kay

2008-03-01

A method is presented to assess lake water-groundwater interactions by modelling isotope signatures of lake water using meteorological parameters and field data. The modelling of delta(18)O and deltaD variations offers information about the groundwater influx into a meromictic Lusatian mining lake. Therefore, a water balance model is combined with an isotope water balance model to estimate analogies between simulated and measured isotope signatures within the lake water body. The model is operated with different evaporation rates to predict delta(18)O and deltaD values in a lake that is only controlled by weather conditions with neither groundwater inflow nor outflow. Comparisons between modelled and measured isotope values show whether the lake is fed by the groundwater or not. Furthermore, our investigations show that an adaptation of the Craig and Gordon model [H. Craig, L.I. Gordon. Deuterium and oxygen-18 variations in the ocean and the marine atmosphere. In Stable Isotopes in Oceanographic Studies and Paleotemperature, Spoleto, E. Tongiorgi (Ed.), pp. 9-130, Consiglio Nazionale delle Ricerche, Laboratorio di Geologia Nucleare, Pisa (1965).] to specific conditions in temperate regions seems necessary.

75 FR 8789 - Research Advisory Committee on Gulf War Veterans' Illnesses; Notice of Meeting

Science.gov (United States)

2010-02-25

... DEPARTMENT OF VETERANS AFFAIRS Research Advisory Committee on Gulf War Veterans' Illnesses; Notice... Advisory Committee Act) that the Research Advisory Committee on Gulf War Veterans' Illnesses will meet on... theater of operations during the Gulf War. The Committee will review VA program activities related to Gulf...

Lake Sturgeon, Acipenser fulvescens, movements in Rainy Lake, Minnesota and Ontario

Science.gov (United States)

Adams, W.E.; Kallemeyn, L.W.; Willis, D.W.

2006-01-01

Rainy Lake, Minnesota-Ontario, contains a native population of Lake Sturgeon (Acipenser fulvescens) that has gone largely unstudied. The objective of this descriptive study was to summarize generalized Lake Sturgeon movement patterns through the use of biotelemetry. Telemetry data reinforced the high utilization of the Squirrel Falls geographic location by Lake Sturgeon, with 37% of the re-locations occurring in that area. Other spring aggregations occurred in areas associated with Kettle Falls, the Pipestone River, and the Rat River, which could indicate spawning activity. Movement of Lake Sturgeon between the Seine River and the South Arm of Rainy Lake indicates the likelihood of one integrated population on the east end of the South Arm. The lack of re-locations in the Seine River during the months of September and October may have been due to Lake Sturgeon moving into deeper water areas of the Seine River and out of the range of radio telemetry gear or simply moving back into the South Arm. Due to the movements between Minnesota and Ontario, coordination of management efforts among provincial, state, and federal agencies will be important.

Long-term changes of fisheries landings in enclosed gulf lagoons (Amvrakikos gulf, W Greece): Influences of fishing and other human impacts

Science.gov (United States)

Katselis, George N.; Moutopoulos, Dimitrios K.; Dimitriou, Evagelos N.; Koutsikopoulos, Constantin

2013-10-01

The present study analyses long-term annual fishery landings time series (1980-2007) for species derived from six lagoons (covering about 70 km2) around an important European wetland, the fjord-like Amvrakikos gulf. Landing trends for most abundant species revealed that typical lagoon fish species-groups, such as Mugilidae (Mugil cephalus, Chelon labrosus, Liza saliens, Liza aurata and Liza ramada), eels (Anguilla anguilla) and Gobies (mainly Zosteriosessor ophiocephalus) had largely decreased, while the landings of Sparus aurata increased during the entire study period. These trends led to a significant change in species composition during recent years that might be attributed to large-scale climatic changes as well as serious anthropogenic impacts that degraded the water quality and altered the hydrology within the gulf and lagoons, the increase of fishing exploitation in Amvrakikos gulf, the expansion of aquaculture activities within the gulf, the application of new fishing management practices in lagoons, and the increase of fish-eating sea-bird populations. The findings are needed for the implementation of an efficient and integrated management tool for the study of coastal systems.

Determining lake surface water temperatures worldwide using a tuned one-dimensional lake model (FLake, v1)

Science.gov (United States)

Layden, Aisling; MacCallum, Stuart N.; Merchant, Christopher J.

2016-06-01

A tuning method for FLake, a one-dimensional (1-D) freshwater lake model, is applied for the individual tuning of 244 globally distributed large lakes using observed lake surface water temperatures (LSWTs) derived from along-track scanning radiometers (ATSRs). The model, which was tuned using only three lake properties (lake depth, snow and ice albedo and light extinction coefficient), substantially improves the measured mean differences in various features of the LSWT annual cycle, including the LSWTs of saline and high altitude lakes, when compared to the observed LSWTs. Lakes whose lake-mean LSWT persists below 1 °C for part of the annual cycle are considered to be seasonally ice-covered. For trial seasonally ice-covered lakes (21 lakes), the daily mean and standard deviation (2σ) of absolute differences between the modelled and observed LSWTs are reduced from 3.07 °C ± 2.25 °C to 0.84 °C ± 0.51 °C by tuning the model. For all other trial lakes (14 non-ice-covered lakes), the improvement is from 3.55 °C ± 3.20 °C to 0.96 °C ± 0.63 °C. The post tuning results for the 35 trial lakes (21 seasonally ice-covered lakes and 14 non-ice-covered lakes) are highly representative of the post-tuning results of the 244 lakes. For the 21 seasonally ice-covered lakes, the modelled response of the summer LSWTs to changes in snow and ice albedo is found to be statistically related to lake depth and latitude, which together explain 0.50 (R2adj, p = 0.001) of the inter-lake variance in summer LSWTs. Lake depth alone explains 0.35 (p = 0.003) of the variance. Lake characteristic information (snow and ice albedo and light extinction coefficient) is not available for many lakes. The approach taken to tune the model, bypasses the need to acquire detailed lake characteristic values. Furthermore, the tuned values for lake depth, snow and ice albedo and light extinction coefficient for the 244 lakes provide some guidance on improving FLake LSWT modelling.

Observing environmental change in of the Gulf of Maine: ICUC smartphone app

Science.gov (United States)

Want to help collect data on environmental change in the Gulf of Maine with your smartphone? The Gulf of Maine Council’s EcoSystem Indicator Partnership (ESIP) is growing the community of citizen scientists in the Gulf of Maine region through its new smartphone app: ICUC (...

Report A, chemical oceanographic data from the Persian Gulf and Gulf of Oman from 17 April 1972 to 17 March 1978 (NODC Accession 7900091)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Temperature profile and chemical data were collected using bottle casts from NOAA Ship DELAWARE and other platforms in the Persian Gulf and Gulf of Oman from 17...

Geochemical monitoring of volcanic lakes. A generalized box model for active crater lakes

Directory of Open Access Journals (Sweden)

Franco Tassi

2011-06-01

Full Text Available

In the past, variations in the chemical contents (SO42−, Cl−, cations of crater lake water have not systematically demonstrated any relationships with eruptive activity. Intensive parameters (i.e., concentrations, temperature, pH, salinity should be converted into extensive parameters (i.e., fluxes, changes with time of mass and solutes, taking into account all the internal and external chemical–physical factors that affect the crater lake system. This study presents a generalized box model approach that can be useful for geochemical monitoring of active crater lakes, as highly dynamic natural systems. The mass budget of a lake is based on observations of physical variations over a certain period of time: lake volume (level, surface area, lake water temperature, meteorological precipitation, air humidity, wind velocity, input of spring water, and overflow of the lake. This first approach leads to quantification of the input and output fluxes that contribute to the actual crater lake volume. Estimating the input flux of the "volcanic" fluid (Qf- kg/s –– an unmeasurable subsurface parameter –– and tracing its variations with time is the major focus during crater lake monitoring. Through expanding the mass budget into an isotope and chemical budget of the lake, the box model helps to qualitatively characterize the fluids involved. The (calculated Cl− content and dD ratio of the rising "volcanic" fluid defines its origin. With reference to continuous monitoring of crater lakes, the present study provides tips that allow better calculation of Qf in the future. At present, this study offers the most comprehensive and up-to-date literature review on active crater lakes.

Water-quality and lake-stage data for Wisconsin lakes, water year 2014

Science.gov (United States)

Manteufel, S. Bridgett; Robertson, Dale M.

2017-05-25

IntroductionThe U.S. Geological Survey (USGS), in cooperation with local and other agencies, collects data at selected lakes throughout Wisconsin. These data, accumulated over many years, provide a database for developing an improved understanding of the water quality of lakes. To make these data available to interested parties outside the USGS, the data are published annually in this report series. The locations of water-quality and lake-stage stations in Wisconsin for water year 2014 are shown in figure 1. A water year is the 12-month period from October 1 through September 30. It is designated by the calendar year in which it ends. Thus, the periodOctober 1, 2013, through September 30, 2014, is called “water year 2014.”The purpose of this report is to provide information about the chemical and physical characteristics of Wisconsin lakes. Data that have been collected at specific lakes, and information to aid in the interpretation of those data, are included in this report. Data collected include measurements of in-lake water quality and lake stage. Time series of Secchi depths, surface total phosphorus, and chlorophyll a concentrations collected during nonfrozen periods are included for many lakes. Graphs of vertical profiles of temperature, dissolved oxygen, pH, and specific conductance are included for sites where these parameters were measured. Descriptive information for each lake includes the location of the lake, area of the lake’s watershed, period for which data are available, revisions to previously published records, and pertinent remarks. Additional data, such as streamflow and water quality in tributary and outlet streams of some of the lakes, are published online at http://nwis.waterdata.usgs.gov/wi/nwis.Water-resources data, including stage and discharge data at most streamflow-gaging stations, are available online. The Wisconsin Water Science Center’s home page is at https://www.usgs.gov/centers/wisconsin-water-science-center. Information

Increased psychological distress among Danish Gulf War veterans--without evidence for a neurotoxic background. The Danish Gulf War Study

DEFF Research Database (Denmark)

Ishøy, Torben; Knop, Joachim; Suadicani, Poul

2004-01-01

INTRODUCTION: Compared with controls, up to six years after their return, Danish Gulf War veterans have a significantly higher prevalence of self-reported neuropsychological symptoms, potentially as a result of neurotoxic exposure during deployment. We tested the hypotheses that: 1) GW veterans...... of neuropsychological symptoms, and stratified according to SCL-90-R score, no trends were found suggesting reduced motor function with increasing symptoms. Of nine dimensions constructed on the basis of the SCL-90-R items, six were significantly associated with being a Gulf War veteran. Statistically, the strongest...... would perform less well than controls using a computerized neuromotor test battery; and that 2) GW veterans have a psychological profile different from that of controls. MATERIAL AND METHODS: A cross-sectional study of 686 subjects who had been deployed in the Persian Gulf within the period August 2...

Good Order at Sea in the Gulf of Guinea

DEFF Research Database (Denmark)

Nordby, Johannes Riber; Lindskov Jacobsen, Katja

In this chapter, we first outline the maritime security situation in the Gulf of Guinea region at present. It is examined in the context of Good Order at Sea. Second, we describe the most recent maritime security initiative launched during the Yaoundé Summit in 2013. During the summit, West...... and Central African states decided to establish six maritime zones along their coastline in order to improve the maritime security in the Gulf of Guinea. A process heavily supported by UN’s International Maritime Organisation (IMO). Finally, the chapter suggests that maritime security issues in the Gulf...

Gulf of Mexico Regional Collaborative Final Report

Energy Technology Data Exchange (ETDEWEB)

Judd, Kathleen S. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Judd, Chaeli [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Engel-Cox, Jill A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Gulbransen, Thomas [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Anderson, Michael G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Woodruff, Dana L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Thom, Ronald M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Guzy, Michael [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Hardin, Danny [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Estes, Maury [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2007-12-01

This report presents the results of the Gulf of Mexico Regional Collaborative (GoMRC), a year-long project funded by NASA. The GoMRC project was organized around end user outreach activities, a science applications team, and a team for information technology (IT) development. Key outcomes are summarized below for each of these areas. End User Outreach; Successfully engaged federal and state end users in project planning and feedback; With end user input, defined needs and system functional requirements; Conducted demonstration to End User Advisory Committee on July 9, 2007 and presented at Gulf of Mexico Alliance (GOMA) meeting of Habitat Identification committee; Conducted significant engagement of other end user groups, such as the National Estuary Programs (NEP), in the Fall of 2007; Established partnership with SERVIR and Harmful Algal Blooms Observing System (HABSOS) programs and initiated plan to extend HABs monitoring and prediction capabilities to the southern Gulf; Established a science and technology working group with Mexican institutions centered in the State of Veracruz. Key team members include the Federal Commission for the Protection Against Sanitary Risks (COFEPRIS), the Ecological Institute (INECOL) a unit of the National Council for science and technology (CONACYT), the Veracruz Aquarium (NOAA’s first international Coastal Ecology Learning Center) and the State of Veracruz. The Mexican Navy (critical to coastal studies in the Southern Gulf) and other national and regional entities have also been engaged; and Training on use of SERVIR portal planned for Fall 2007 in Veracruz, Mexico Science Applications; Worked with regional scientists to produce conceptual models of submerged aquatic vegetation (SAV) ecosystems; Built a logical framework and tool for ontological modeling of SAV and HABs; Created online guidance for SAV restoration planning; Created model runs which link potential future land use trends, runoff and SAV viability; Analyzed SAV

Lake Michigan lake trout PCB model forecast post audit (oral presentation)

Science.gov (United States)

Scenario forecasts for total PCBs in Lake Michigan (LM) lake trout were conducted using the linked LM2-Toxics and LM Food Chain models, supported by a suite of additional LM models. Efforts were conducted under the Lake Michigan Mass Balance Study and the post audit represents an...

Simulating Lake-Groundwater Interactions During Decadal Climate Cycles: Accounting For Variable Lake Area In The Watershed

Science.gov (United States)

Virdi, M. L.; Lee, T. M.

2009-12-01

The volume and extent of a lake within the topo-bathymetry of a watershed can change substantially during wetter and drier climate cycles, altering the interaction of the lake with the groundwater flow system. Lake Starr and other seepage lakes in the permeable sandhills of central Florida are vulnerable to climate changes as they rely exclusively on rainfall and groundwater for inflows in a setting where annual rainfall and recharge vary widely. The groundwater inflow typically arrives from a small catchment area bordering the lake. The sinkhole origin of these lakes combined with groundwater pumping from underlying aquifers further complicate groundwater interactions. Understanding the lake-groundwater interactions and their effects on lake stage over multi-decadal climate cycles is needed to manage groundwater pumping and public expectation about future lake levels. The interdependence between climate, recharge, changing lake area and the groundwater catchment pose unique challenges to simulating lake-groundwater interactions. During the 10-year study period, Lake Starr stage fluctuated more than 13 feet and the lake surface area receded and expanded from 96 acres to 148 acres over drier and wetter years that included hurricanes, two El Nino events and a La Nina event. The recently developed Unsaturated Zone Flow (UZF1) and Lake (LAK7) packages for MODFLOW-2005 were used to simulate the changing lake sizes and the extent of the groundwater catchment contributing flow to the lake. The lake area was discretized to occupy the largest surface area at the highest observed stage and then allowed to change size. Lake cells convert to land cells and receive infiltration as receding lake area exposes the underlying unsaturated zone to rainfall and recharge. The unique model conceptualization also made it possible to capture the dynamic size of the groundwater catchment contributing to lake inflows, as the surface area and volume of the lake changed during the study

Lake Granbury and Lake Whitney Assessment Initiative Final Scientific/Technical Report Summary

Energy Technology Data Exchange (ETDEWEB)

Harris, B. L. [Texas AgriLife Research, College Station, TX (United States); Roelke, Daniel [Texas AgriLife Research, College Station, TX (United States); Brooks, Bryan [Texas AgriLife Research, College Station, TX (United States); Grover, James [Texas AgriLife Research, College Station, TX (United States)

2010-10-11

A team of Texas AgriLife Research, Baylor University and University of Texas at Arlington researchers studied the biology and ecology of Prymnesium parvum (golden algae) in Texas lakes using a three-fold approach that involved system-wide monitoring, experimentation at the microcosm and mesocosm scales, and mathematical modeling. The following are conclusions, to date, regarding this organism's ecology and potential strategies for mitigation of blooms by this organism. In-lake monitoring revealed that golden algae are present throughout the year, even in lakes where blooms do not occur. Compilation of our field monitoring data with data collected by Texas Parks and Wildlife and Brazos River Authority (a period spanning a decade) revealed that inflow and salinity variables affect bloom formations. Thresholds for algae populations vary per lake, likely due to adaptations to local conditions, and also to variations in lake-basin morphometry, especially the presence of coves that may serve as hydraulic storage zones for P. parvum populations. More specifically, our in-lake monitoring showed that the highly toxic bloom that occurred in Lake Granbury in the winter of 2006/2007 was eliminated by increased river inflow events. The bloom was flushed from the system. The lower salinities that resulted contributed to golden algae not blooming in the following years. However, flushing is not an absolute requirement for bloom termination. Laboratory experiments have shown that growth of golden algae can occur at salinities ~1-2 psu but only when temperatures are also low. This helps to explain why blooms are possible during winter months in Texas lakes. Our in-lake experiments in Lake Whitney and Lake Waco, as well as our laboratory experiments, revealed that cyanobacteria, or some other bacteria capable of producing algicides, were able to prevent golden algae from blooming. Identification of this organism is a high priority as it may be a key to managing golden algae

Geophysical investigation of sentinel lakes in Lake, Seminole, Orange, and Volusia Counties, Florida

Science.gov (United States)

Reich, Christopher; Flocks, James; Davis, Jeffrey

2012-01-01

This study was initiated in cooperation with the St. Johns River Water Management District (SJRWMD) to investigate groundwater and surface-water interaction in designated sentinel lakes in central Florida. Sentinel lakes are a SJRWMD established set of priority water bodies (lakes) for which minimum flows and levels (MFLs) are determined. Understanding both the structure and lithology beneath these lakes can ultimately lead to a better understanding of the MFLs and why water levels fluctuate in certain lakes more so than in other lakes. These sentinel lakes have become important water bodies to use as water-fluctuation indicators in the SJRWMD Minimum Flows and Levels program and will be used to define long-term hydrologic and ecologic performance measures. Geologic control on lake hydrology remains poorly understood in this study area. Therefore, the U.S. Geological Survey investigated 16 of the 21 water bodies on the SJRWMD priority list. Geologic information was obtained by the tandem use of high-resolution seismic profiling (HRSP) and direct-current (DC) resistivity profiling to isolate both the geologic framework (structure) and composition (lithology). Previous HRSP surveys from various lakes in the study area have been successful in identifying karst features, such as subsidence sinkholes. However, by using this method only, it is difficult to image highly irregular or chaotic surfaces, such as collapse sinkholes. Resistivity profiling was used to complement HRSP by detecting porosity change within fractured or collapsed structures and increase the ability to fully characterize the subsurface. Lake Saunders (Lake County) is an example of a lake composed of a series of north-south-trending sinkholes that have joined to form one lake body. HRSP shows surface depressions and deformation in the substrate. Resistivity data likewise show areas in the southern part of the lake where resistivity shifts abruptly from approximately 400 ohm meters (ohm-m) along the

76 FR 60807 - Gulf of Mexico Fishery Management Council; Public Meeting; Correction

Science.gov (United States)

2011-09-30

... to a Council meeting. SUMMARY: The Gulf of Mexico Fishery Management Council will convene a meeting... Thursday, October 13, 2011. ADDRESSES: The meeting will be held at the Gulf of Mexico Fishery Management Council, 2203 North Lois Avenue, Suite 1100, Tampa, FL 33607. Council address: Gulf of Mexico Fishery...

Central Gulf of Mexico lease sale draws weak industry response

International Nuclear Information System (INIS)

Koen, A.D.

1992-01-01

This paper reports that interest in oil and gas leases in the Gulf of Mexico continued spiraling downward at the latest Minerals Management Service offshore sale. Companies participating in Outer Continental Shelf Sale 139 last week in New Orleans offered 196 bids for 151 blocks in the central Gulf of Mexico. MMS offered 5,213 blocks for lease. The number of tracts receiving bids was the fewest at a central gulf lease sale since 114 tracts garnered high bids totaling $146.4 million at Sale 104 in April 1986. Apparent high bids in Sale 139 totaled $56,195,552, and all bids offered totaled just $65,300,864. Both bidding totals were the lowest in a Gulf of Mexico lease sale since MMS began area-wide gulf leasing at Sale 72 in May 1983. Only 64 of 93 qualified companies participated in Sale 139. Fifty-five companies offered apparent winning bids. By comparison, 123 companies at central gulf lease Sale 131 in March 1991 offered 637 bids totaling $320.5 million for 464 tracts. Apparent high bids last spring totaled $259.9 million. At central gulf lease Sale 123 in March 1990, high bids totaled $427.4 million for 538 tracts. In that sale, BP Exploration Inc. led all bidders, exposing $78 million in 79 high bids, including 60 for deepwater tracts. Since then, interest in deepwater tracts has waned in part because of sagging oil and gas prices as U.S. operators sought bigger prospects outside the U.S. Ironically, Sale 139 was dominated by the U.S. subsidiary of an Italian holding company

Great Lakes Literacy Principles

Science.gov (United States)

Fortner, Rosanne W.; Manzo, Lyndsey

2011-03-01

Lakes Superior, Huron, Michigan, Ontario, and Erie together form North America's Great Lakes, a region that contains 20% of the world's fresh surface water and is home to roughly one quarter of the U.S. population (Figure 1). Supporting a $4 billion sport fishing industry, plus $16 billion annually in boating, 1.5 million U.S. jobs, and $62 billion in annual wages directly, the Great Lakes form the backbone of a regional economy that is vital to the United States as a whole (see http://www.miseagrant.umich.edu/downloads/economy/11-708-Great-Lakes-Jobs.pdf). Yet the grandeur and importance of this freshwater resource are little understood, not only by people in the rest of the country but also by many in the region itself. To help address this lack of knowledge, the Centers for Ocean Sciences Education Excellence (COSEE) Great Lakes, supported by the U.S. National Science Foundation and the National Oceanic and Atmospheric Administration, developed literacy principles for the Great Lakes to serve as a guide for education of students and the public. These “Great Lakes Literacy Principles” represent an understanding of the Great Lakes' influences on society and society's influences on the Great Lakes.

Human impact on lake ecosystems: the case of Lake Naivasha, Kenya

African Journals Online (AJOL)

Lake Naivasha is a wetland of national and international importance. However, it is under constant anthropogenic pressures, which include the quest for socioeconomic development within the lake ecosystem itself as well as other activities within the catchment. The lake is an important source of fresh water in an otherwise ...

Lake whitefish and Diporeia spp. in the Great lakes: an overview

Science.gov (United States)

Nalepa, Thomas F.; Mohr, Lloyd C.; Henderson, Bryan A.; Madenjian, Charles P.; Schneeberger, Philip J.

2005-01-01

Because of growing concern in the Great Lakes over declines in abundance and growth of lake whitefish (Coregonus clupeaformis) and declines in abundance of the benthic amphipod Diporeia spp., a workshop was held to examine past and current trends, to explore trophic links, and to discuss the latest research results and needs. The workshop was divided into sessions on the status of populations in each of the lakes, bioenergetics and trophic dynamics, and exploitation and management. Abundance, growth, and condition of whitefish populations in Lakes Superior and Erie are stable and within the range of historical means, but these variables are declining in Lakes Michigan and Ontario and parts of Lake Huron. The loss of Diporeia spp., a major food item of whitefish, has been a factor in observed declines, particularly in Lake Ontario, but density-dependent factors also likely played a role in Lakes Michigan and Huron. The loss of Diporeia spp. is temporally linked to the introduction and proliferation of dreissenid mussels, but a direct cause for the negative response of Diporeia spp. has not been established. Given changes in whitefish populations, age-structured models need to be re-evaluated. Other whitefish research needs to include a better understanding of what environmental conditions lead to strong year-classes, improved aging techniques, and better information on individual population (stock) structure. Further collaborations between assessment biologists and researchers studying the lower food web would enhance an understanding of links between trophic levels.

Future role of Gulf oil in world energy demand

International Nuclear Information System (INIS)

Eltony, M.N.

1998-01-01

The view that there will be a growing dependence on oil from the Gulf countries is shared by a great number of oil market analysts. This view is based on the fact that Gulf countries dominate the global oil reserves. Energy analyst argue that as the world demand for oil continues to grow driven largely by the growth in developing countries' consumption coupled with constrained non-OPEC supply, the end result will be that the call on Gulf oil will grow substantially. In summary, this paper has challenged the view of growing dependence on oil from the Gulf using available information in conjunction with reasonable and fairly plausible arguments. The aim was to point out to the GCC member counties the danger of relying on these views in shaping their economic policies and in setting their oil market strategies. They may run the ultimate risk of being left with huge oil reserves that no one wants. (orig.)

Sources and distribution of microplastics in China's largest inland lake - Qinghai Lake.

Science.gov (United States)

Xiong, Xiong; Zhang, Kai; Chen, Xianchuan; Shi, Huahong; Luo, Ze; Wu, Chenxi

2018-04-01

Microplastic pollution was studied in China's largest inland lake - Qinghai Lake in this work. Microplastics were detected with abundance varies from 0.05 × 10 5 to 7.58 × 10 5 items km -2 in the lake surface water, 0.03 × 10 5 to 0.31 × 10 5 items km -2 in the inflowing rivers, 50 to 1292 items m -2 in the lakeshore sediment, and 2 to 15 items per individual in the fish samples, respectively. Small microplastics (0.1-0.5 mm) dominated in the lake surface water while large microplastics (1-5 mm) are more abundant in the river samples. Microplastics were predominantly in sheet and fiber shapes in the lake and river water samples but were more diverse in the lakeshore sediment samples. Polymer types of microplastics were mainly polyethylene (PE) and polypropylene (PP) as identified using Raman Spectroscopy. Spatially, microplastic abundance was the highest in the central part of the lake, likely due to the transport of lake current. Based on the higher abundance of microplastics near the tourist access points, plastic wastes from tourism are considered as an important source of microplastics in Qinghai Lake. As an important area for wildlife conservation, better waste management practice should be implemented, and waste disposal and recycling infrastructures should be improved for the protection of Qinghai Lake. Copyright © 2018 Elsevier Ltd. All rights reserved.

Gulf Canada Resources Limited 1998 annual report

International Nuclear Information System (INIS)

1999-01-01

A review of operations in 1998 and financial information from Gulf Canada Resources Limited is provided to keep shareholders abreast of company performance. Gulf Canada Resources Limited explores for, develops, produces and markets conventional and synthetic crude oil, natural gas and natural gas liquids. In 1998, the company's main operating centres were in western Canada (where it owns a nine per cent interest in the Syncrude Joint Venture), Indonesia, the North Sea and Australia. The report summarizes the company's energy resource activities, presents a detailed review of operations, and provides consolidated financial statements, and common share information. Although Gulf Canada Resources sold $ 1.2 billion worth of non-producing assets during the year, year end proved reserves of 838 million barrels of oil equivalent were less than ten per cent lower than a year earlier, reflecting reserve additions of 100 million barrels of oil equivalent. tabs., figs

Energy benchmarking for shopping centers in Gulf Coast region

International Nuclear Information System (INIS)

Juaidi, Adel; AlFaris, Fadi; Montoya, Francisco G.; Manzano-Agugliaro, Francisco

2016-01-01

Building sector consumes a significant amount of energy worldwide (up to 40% of the total global energy); moreover, by the year 2030 the consumption is expected to increase by 50%. One of the reasons is that the performance of buildings and its components degrade over the years. In recent years, energy benchmarking for government office buildings, large scale public buildings and large commercial buildings is one of the key energy saving projects for promoting the development of building energy efficiency and sustainable energy savings in Gulf Cooperation Council (GCC) countries. Benchmarking would increase the purchase of energy efficient equipment, reducing energy bills, CO_2 emissions and conventional air pollution. This paper focuses on energy benchmarking for shopping centers in Gulf Coast Region. In addition, this paper will analyze a sample of shopping centers data in Gulf Coast Region (Dubai, Ajman, Sharjah, Oman and Bahrain). It aims to develop a benchmark for these shopping centers by highlighting the status of energy consumption performance. This research will support the sustainability movement in Gulf area through classifying the shopping centers into: Poor, Usual and Best Practices in terms of energy efficiency. According to the benchmarking analysis in this paper, the shopping centers best energy management practices in the Gulf Coast Region are the buildings that consume less than 810 kW h/m"2/yr, whereas the poor building practices are the centers that consume greater than 1439 kW h/m"2/yr. The conclusions of this work can be used as a reference for shopping centres benchmarking with similar climate. - Highlights: •The energy consumption data of shopping centers in Gulf Coast Region were gathered. •A benchmarking of energy consumption for the public areas for the shopping centers in the Gulf Coast Region was developed. •The shopping centers have the usual practice in the region between 810 kW h/m"2/yr and 1439 kW h/m"2/yr.

Outflows of groundwater in lakes: case study of Lake Raduńske Górne

Directory of Open Access Journals (Sweden)

Cieśliński Roman

2014-12-01

Full Text Available The aim of the study was to locate and describe groundwater outflows in a selected lake basin. The study hypothesis was based on the fact that, according to the specialist literature, one of the forms of lake water supply is through groundwater outflows. It was also assumed that the lakes of the Kashubian Lake District are characterised by such a form of lake water supply. The time scope of the work included the period from January 2011 to September 2012. The spatial scope of the work included the area of Lake Raduńskie Górne, located in the Kashubian Lake District in north Poland. The research plot was in the north-eastern part of the lake. Office works were aimed at gathering and studying source materials and maps. Cartographic materials were analysed with the use of the MapInfo Professional 9.5. The purpose of the field work was to find the groundwater outflows in the basin of Lake Raduńskie Górne. During the field research diving was carried out in the lake. During the dive audiovisual documentation was conducted using a Nikon D90 camera with Ikelite underwater housing for Nikon D90 and an Ikelite DS 161 movie substrobe, as well as a GoPro HD HERO 2 Outdoor camera. During the project, four groundwater outflows were found. In order to examine these springs audiovisual and photographic documentation was made. To systematise the typology of the discovered springs, new nomenclature was suggested, namely under-lake springs with subtypes: an under-lake slope spring and under-lake offshore spring

Changing values of lake ecosystem services as a result of bacteriological contamination on Lake Trzesiecko and Lake Wielimie, Poland

Directory of Open Access Journals (Sweden)

Cichoń Małgorzata

2017-12-01

Full Text Available Lake ecosystems, on the one hand, are affected by tourism, and on the other by development for tourism. Lake ecosystem services include: water with its self-cleaning processes, air with climate control processes, as well as flora and fauna. Utilisation of services leads to interventions in the structure of ecosystems and their processes. Only to a certain extent, this is specific to each type of environmental interference, remains within the limits of ecosystem resilience and does not lead to its degradation. One of the threats is bacteriological contamination, for which the most reliable sanitation indicator is Escherichia coli. In lake water quality studies it is assumed that the lakeshore cannot be a source of bacteria. It has been hypothesised that the problem of bacterial contamination can be serious for the places that do not have any infrastructure, especially sanitation. Consequently, the purpose of the study was to determine the extent to which lakeshore sanitation, in particular the level of bacteriological contamination, has an impact on the value of services provided by the selected lake ecosystems (Lake Trzesiecko and Lake Wielimie – Szczecinek Lake District. Five selected services related to lake ecosystems are: water, control over the spread of contagious diseases, aesthetic values, tourism and recreation, as well as the hydrological cycle with its self-cleaning function. Services, as well as the criteria adopted for evaluation, allow us to conclude that the services provided by the lake ecosystems are suitable to fulfill a recreation function. However, the inclusion of quality criteria for sanitary status has shown that the value of system services has dropped by as much as 50%. Value changes are visible primarily for water and aesthetic qualities. Such a significant decrease in the value of services clearly indicates the importance of the sanitary conditions of lakes and their appropriate infrastructure. In view of the

78 FR 12294 - Gulf of Mexico Fishery Management Council (Council); Public Meetings

Science.gov (United States)

2013-02-22

... meetings. SUMMARY: The Gulf of Mexico and South Atlantic Fishery Management Councils will convene a Science.... to 4 p.m. EST on Tuesday, March 12, 2013. ADDRESSES: The meeting will be held at the Gulf of Mexico.... Council address: Gulf of Mexico Fishery Management Council, 2203 North Lois Avenue, Suite 1100, Tampa, FL...

Resilience and Restoration of Lakes

Directory of Open Access Journals (Sweden)

Stephen R. Carpenter

1997-06-01

Full Text Available Lake water quality and ecosystem services are normally maintained by several feedbacks. Among these are nutrient retention and humic production by wetlands, nutrient retention and woody habitat production by riparian forests, food web structures that cha nnel phosphorus to consumers rather than phytoplankton, and biogeochemical mechanisms that inhibit phosphorus recycling from sediments. In degraded lakes, these resilience mechanisms are replaced by new ones that connect lakes to larger, regional economi c and social systems. New controls that maintain degraded lakes include runoff from agricultural and urban areas, absence of wetlands and riparian forests, and changes in lake food webs and biogeochemistry that channel phosphorus to blooms of nuisance al gae. Economic analyses show that degraded lakes are significantly less valuable than normal lakes. Because of this difference in value, the economic benefits of restoring lakes could be used to create incentives for lake restoration.

Seasonal phytoplankton blooms in the Gulf of Aden revealed by remote sensing

KAUST Repository

Gittings, John

2016-11-25

The Gulf of Aden, situated in the northwest Arabian Sea and linked to the Red Sea, is a relatively unexplored ecosystem. Understanding of large-scale biological dynamics is limited by the lack of adequate datasets. In this study, we analyse 15 years of remotely-sensed chlorophyll-a data (Chl-a, an index of phytoplankton biomass) acquired from the Ocean Colour Climate Change Initiative (OC-CCI) of the European Space Agency (ESA). The improved spatial coverage of OC-CCI data in the Gulf of Aden allows, for the first time, an investigation into the full seasonal succession of phytoplankton biomass. Analysis of indices of phytoplankton phenology (bloom timing) reveals distinct phytoplankton growth periods in different parts of the gulf: a large peak during August (mid-summer) in the western part of the gulf, and a smaller peak during November (mid-autumn) in the lower central gulf and along the southern coastline. The summer bloom develops rapidly at the beginning of July, and its peak is approximately three times higher than that of the autumnal bloom. Remotely-sensed sea-surface temperature (SST), wind-stress curl, vertical nutrient profiles and geostrophic currents inferred from the sea-level anomaly, were analysed to examine the underlying physical mechanisms that control phytoplankton growth. During summer, the prevailing southwesterlies cause upwelling along the northern coastline of the gulf (Yemen), leading to an increase in nutrient availability and enhancing phytoplankton growth along the coastline and in the western part of the gulf. In contrast, in the central region of the gulf, lowest concentrations of Chl-a are observed during summer, due to strong downwelling caused by a mesoscale anticyclonic eddy. During autumn, the prevailing northeasterlies enable upwelling along the southern coastline (Somalia) causing local nutrient enrichment in the euphotic zone, leading to higher levels of phytoplankton biomass along the coastline and in the lower central gulf

Biomarker Discovery in Gulf War Veterans: Development of a War Illness Diagnostic Panel

Science.gov (United States)

2016-12-01

Award Number: W81XWH-12-1-0382 TITLE: Biomarker Discovery in Gulf War Veterans: Development of a War Illness Diagnostic Panel PRINCIPAL...SUBTITLE Biomarker Discovery in Gulf War Veterans: Development of a War Illness Diagnostic Panel 5a. CONTRACT NUMBER W81XWH-12-1-0382 5b. GRANT...of the 1990-1991 Gulf War are affected by Gulf War illness (GWI), the chronic condition currently defined only by veterans’ self-reported symptoms

Effect of Diet on Gulf War Illness: A Pilot Study

Science.gov (United States)

2017-10-01

Award Number: W81XWH-15-1-0636 TITLE: Effect of Diet on Gulf War Illness: A Pilot Study PRINCIPAL INVESTIGATOR: Ashok Tuteja, M.D. M.P.H...CONTRACT NUMBER Effect of Diet on Gulf War Illness 5b. GRANT NUMBER W81XWH-15-1-0636 5c. PROGRAM ELEMENT NUMBER 6 . AUTHOR(S) 5d. PROJECT NUMBER...headache) in Veterans with Gulf War Illness. We will also determine if the change in gut flora is a mechanism for improvement in symptoms of IBS and GW

Environmental impacts of tourism in the Gulf and the Red Sea.

Science.gov (United States)

Gladstone, William; Curley, Belinda; Shokri, Mohammad Reza

2013-07-30

The Gulf and Red Sea possess diverse coastal and marine environments that support rapidly expanding mass tourism. Despite the associated environmental risks, there is no analysis of the tourism-related literature or recent analysis of impacts. Environmental issues reported in 101 publications (25 from the Gulf, 76 from the Red Sea) include 61 purported impacts (27 from the Gulf, 45 from the Red Sea). Gulf literature includes quantitative studies (68% publications) and reviews (32%), and addresses mostly land reclamation and artificial habitats. Most Gulf studies come from Iran and UAE (64%). Red Sea literature includes quantitative studies (81%) and reviews (11%), with most studies occurring in Egypt (70%). The most published topics relate to coral breakage and its management. A full account of tourism's environmental impacts is constrained by limited tourism data, confounding of impacts with other coastal developments, lack of baseline information, shifting baselines, and fragmentation of research across disciplines. Copyright © 2012 Elsevier Ltd. All rights reserved.

Gulf War syndrome: an emerging threat or a piece of history?

Science.gov (United States)

Greenberg, N; Wessely, S

2008-01-01

‘Gulf War syndrome’ is a phrase coined after the 1991 Gulf War to group together disparate, unexplained health symptoms in Gulf veterans. This paper examines the many hypotheses that have been put forward about the origins of the concept and gives an overview of the studies that have attempted to explain the lasting health effects associated with Gulf service. Our review finds that although in the UK there has not yet been evidence of a new Gulf War syndrome as a result of the current conflicts in Iraq and Afghanistan, there is a rise in post-conflict psychiatric disorders now being reported in the USA. We postulate that after conflicts military personnel will always face some form of post-conflict syndrome and the nature of the threats experienced is likely to dictate the form the syndrome might take. We also postulate that media reporting is likely to have influenced and to continue unhelpfully to influence the health of service personnel. PMID:22460210

A recent perspective of the Circulation in the Gulf of Mexico

Science.gov (United States)

Candela, J.; Ochoa-de-La-Torre, J. L.; Sheinbaum, J.; Perez-Brunius, P.; Pallas-Sanz, E.; Kolodziejczyk, N.

2013-05-01

The flow through the Gulf of Mexico is an integral part of the North Atlantic Ocean Subtropical Gyre Circulation, known to be forced by the wind over the North Atlantic and by an equivalent contribution from the inter-hemispheric Meridional Overturning Cell. To the North Atlantic Circulation, the Gulf represents an important energy and vorticity sink through the particular behavior of the Loop Current within. Comprehending the structure and dynamics of the Loop Current System (which includes the Yucatan Current (YC), Loop Current (LC), the shedding of anticyclonic Loop Current Eddies (LCE) and peripheral cyclonic gyres) is fundamental for understanding the circulation in the entire Gulf. Within the Gulf, the eastern Loop Current and the western Campeche Bay (CB) regions are characterized by persistent eddy structures, with less structured eddy fields in between. Of these later ones, the northwestern Gulf is a geostrophic turbulence area, constantly perturbed by LCE, which represents, at the same time, an important dissipation and circulation forcing region for the Western Gulf. Important processes recently investigated that will be discussed: 1) The generation and maintenance of the Geostrophic Turbulence field in the north western Gulf. 2) The circulation in deep water induced by the surface geostrophic turbulence field. 3) The generation of intensive jets at depth by interaction of +/- gyres. 4) The generation of coastal trap waves by the interaction of LCEs with the western shelf. 5) The generation of deep topographic Roosby waves by topographic interactions of the LCEs with topography. 5) The characteristics of the Bay of Campeche Circulation, The Campeche Gyre and its interaction with LCEs. 6) The Gulf's response to the passage of hurricanes. 7) The trapping of inertial waves by the LCEs and the related enhanced mixing.

Yellowstone Lake Nanoarchaeota

Directory of Open Access Journals (Sweden)

Scott eClingenpeel

2013-09-01

Full Text Available Considerable Nanoarchaeota novelty and diversity were encountered in Yellowstone Lake, Yellowstone National Park, where sampling targeted lake floor hydrothermal vent fluids, streamers and sediments associated with these vents, and in planktonic photic zones in three different regions of the lake. Significant homonucleotide repeats (HR were observed in pyrosequence reads and in near full-length Sanger sequences, averaging 112 HR per 1,349 bp clone and could confound diversity estimates derived from pyrosequencing, resulting in false nucleotide insertions or deletions (indels. However, Sanger sequencing of two different sets of PCR clones (110 bp, 1349 bp demonstrated that at least some of these indels are real. The majority of the Nanoarchaeota PCR amplicons were vent associated; however, curiously, one relatively small Nanoarchaeota OTU (70 pyrosequencing reads was only found in photic zone water samples obtained from a region of the lake furthest removed from the hydrothermal regions of the lake. Extensive pyrosequencing failed to demonstrate the presence of an Ignicoccus lineage in this lake, suggesting the Nanoarchaeota in this environment are associated with novel Archaea hosts. Defined phylogroups based on near full-length PCR clones document the significant Nanoarchaeota 16S rRNA gene diversity in this lake and firmly establish a terrestrial clade distinct from the marine Nanoarcheota as well as from other geographical locations.

Contaminant trends in lake trout and walleye from the Laurentian Great Lakes

Science.gov (United States)

DeVault, David S.; Hesselberg, Robert J.; Rodgers, Paul W.; Feist, Timothy J.

1996-01-01

Trends in PCBs, DDT, and other contaminants have been monitored in Great Lakes lake trout and walleye since the 1970s using composite samples of whole fish. Dramatic declines have been observed in concentrations of PCB, ΣDDT, dieldrin, and oxychlordane, with declines initially following first order loss kinetics. Mean PCB concentrations in Lake Michigan lake trout increased from 13 μg/g in 1972 to 23 μg/g in 1974, then declined to 2.6 μg/g by 1986. Between 1986 and 1992 there was little change in concentration, with 3.5 μg/g observed in 1992. ΣDDT in Lake Michigan trout followed a similar trend, decreasing from 19.2 μg/g in 1970 to 1.1 μg/g in 1986, and 1.2 μg/g in 1992. Similar trends were observed for PCBs and ΣDDT in lake trout from Lakes Superior, Huron and Ontario. Concentrations of both PCB and ΣDDT in Lake Erie walleye declined between 1977 and 1982, after which concentrations were relatively constant through 1990. When originally implemented it was assumed that trends in the mean contaminant concentrations in open-lake fish would serve as cost effective surrogates to trends in the water column. While water column data are still extremely limited it appears that for PCBs in lakes Michigan and Superior, trends in lake trout do reasonably mimic those in the water column over the long term. Hypotheses to explain the trends in contaminant concentrations are briefly reviewed. The original first order loss kinetics used to describe the initial decline do not explain the more recent leveling off of contaminant concentrations. Recent theories have examined the possibilities of multiple contaminant pools. We suggest another hypothesis, that changes in the food web may have resulted in increased bioaccumulation. However, a preliminary exploration of this hypothesis using a change point analysis was inconclusive.

Characterization of sea floor in Gulf of Mexico

Energy Technology Data Exchange (ETDEWEB)

McGregor, B.A.; Kenyon, N.H.; Schlee, J.S.; Mattick, R.e.; Twichell, D.C.

1986-05-01

In 1985, the US Geological Survey (USGS) conducted a mapping program in the Gulf of Mexico. Using the GLORIA (Geologic Long-Range Inclined Asdic) side-scan sonar system of the Institute of Oceanographic Sciences, USGS mapped approximately 90,000 nmi/sup 2/ of sea floor in the central and western Gulf of Mexico, seaward of the shelf edge. The Sigsbee Escarpment, the seaward edge of a salt front that extends from the western gulf to just west of the Mississippi Canyon, is marked by piles of debris along its base, and is breached by several submarine channels. One such meandering channel can be traced from the shelf edge, through the maze of diapirs on the slope, and out across the Sigsbee Abyssal Plain. This continuous transport pathway indicates the interaction of salt tectonics on sediment pathways and distribution. Numerous bed forms seaward of the Sigsbee Escarpment suggest that strong bottom currents are present. The northern gulf has three major submarine fans, each with different surface morphologies. The Rio Grande Fan has a braided channel system. The Mississippi Fan has a main channel that can be traced for approximately 100 km across the midfan, but most of the surface of the upper and midfan as well as the channel are buried by submarine slides or debris flows. Desoto Canyon Fan also has a continuous channel that has been filled or overrun in places by massive debris flows. Based on the sonographs, mass wasting appears to be an important process in distributing sediments in the deep water of the central gulf.

Use of Cu/Zn-superoxide dismutase tool for biomonitoring marine environment pollution in the Persian Gulf and the Gulf of Oman.

Science.gov (United States)

Zeinali, Farrokhzad; Homaei, Ahmad; Kamrani, Ehsan; Patel, Seema

2018-04-30

Superoxide dismutase (SOD) is the pivotal antioxidant enzyme that defends organisms against the oxidative stresses of superoxide radicals. In this experimental study, purification of SOD from the leaves of Avicennia marina (grey mangrove or white mangrove) from the family Acanthaceae, located in Sirik mangrove forest on the shore of the Gulf of Oman was performed, for the intended characterization of SOD. The Sirik AmSOD (A. marina SOD) expressed optimum activity in the pH range of 6-9 with the maximum activity at pH 8. The optimal temperature for Sirik AmSOD activity was 70°C. Comparison of the pH and temperature optima in two regions (the Persian Gulf and the Gulf of Oman) showed significant differences with P<0.05. The SOD from the Persian Gulf was more resistant against the environmental stressors, because of the biochemical adaption to this environment, which is harsher. The evidence from these results suggests that AmSOD has different characteristics in each place, and mangroves undergo different adaptations and require different protections. The results of the enzymatic research can be useful for ecological management of organisms. Copyright © 2018 Elsevier Inc. All rights reserved.

Pollution at Lake Mariut

International Nuclear Information System (INIS)

Nour ElDin, H.; Halim, S. N.; Shalby, E.

2004-01-01

Lake Mariut, south Alexandria, Egypt suffered in the recent decades from intensive pollution as a result of a continuous discharge of huge amounts of agriculture wastewater that contains a large concentration of the washed pesticides and fertilizers in addition to domestic and industrial untreated wastewater. The over flow from the lake is discharged directly to the sea through El-Max pumping station via EI-Umum drain. Lake Mariout is surrounded by a huge number of different industrial activities and also the desert road is cutting the lake, this means that a huge number of various pollutants cycle through the air and settle down in the lake, by the time and during different seasons these pollutants after accumulation and different chemical interactions will release again from the lake to the surrounding area affecting the surrounding zone

GAOCMAO and its oil spill response activities in the Gulf

International Nuclear Information System (INIS)

Al-Sada, M.S.

1994-01-01

Gulf Area Oil Companies Mutual Aid Organisation (GAOCMAO), has taken active steps in cooperation with its member companies, national and regional environmental organisation (ROPME) in an attempt to protect the Gulf from various sources of pollution. Specific attention was given to oil pollution response in terms of stockpiling of adequate equipment, training of personal and coordination through the application of pre-prepared contingency plans. All these activities tell us that a lot has been done to protect the Gulf environment from pollution. GAOCMAO, after many years of successful development looks to the future with confidence and renewed vigor. It is the intention of this organisation to enhance its member companies capabilities to respond to major incidents and to work closely with the national governmental, regional and international environmental organisations throughout the world, in fields appropriate to the Gulf oil industry. (author)

Reproduction of Persian Gulf anemone fish (Amphiprion clarkii) in captive system

OpenAIRE

Javad Sahandi

2011-01-01

The present study was carried out to assess the reproduction of Persian Gulf anemone fish,Amphiprion clarkii (Bennett, 1830), in captive conditions with artificial features. Persian Gulf, havinggood relation with Indian Ocean, is one of the important niches of fishes and the specific position ofthis Gulf makes its fishes popular. The yellow tail clown fish which originates to this gulf has the bestsurvival rate and health than the other areas. Live food is the most important factor in product...

Long-Term Variability of Satellite Lake Surface Water Temperatures in the Great Lakes

Science.gov (United States)

Gierach, M. M.; Matsumoto, K.; Holt, B.; McKinney, P. J.; Tokos, K.

2014-12-01

The Great Lakes are the largest group of freshwater lakes on Earth that approximately 37 million people depend upon for fresh drinking water, food, flood and drought mitigation, and natural resources that support industry, jobs, shipping and tourism. Recent reports have stated (e.g., the National Climate Assessment) that climate change can impact and exacerbate a range of risks to the Great Lakes, including changes in the range and distribution of certain fish species, increased invasive species and harmful algal blooms, declining beach health, and lengthened commercial navigation season. In this study, we will examine the impact of climate change on the Laurentian Great Lakes through investigation of long-term lake surface water temperatures (LSWT). We will use the ATSR Reprocessing for Climate: Lake Surface Water Temperature & Ice Cover (ARC-Lake) product over the period 1995-2012 to investigate individual and interlake variability. Specifically, we will quantify the seasonal amplitude of LSWTs, the first and last appearances of the 4°C isotherm (i.e., an important identifier of the seasonal evolution of the lakes denoting winter and summer stratification), and interpret these quantities in the context of global interannual climate variability such as ENSO.

Lake Cadagno

DEFF Research Database (Denmark)

Tonolla, Mauro; Storelli, Nicola; Danza, Francesco

2017-01-01

Lake Cadagno (26 ha) is a crenogenic meromictic lake located in the Swiss Alps at 1921 m asl with a maximum depth of 21 m. The presence of crystalline rocks and a dolomite vein rich in gypsum in the catchment area makes the lake a typical “sulphuretum ” dominated by coupled carbon and sulphur...... cycles. The chemocline lies at about 12 m depth, stabilized by density differences of salt-rich water supplied by sub-aquatic springs to the monimolimnion and of electrolyte-poor surface water feeding the mixolimnion. Steep sulphide and light gradients in the chemocline support the growth of a large...... in the chemocline. Small-celled PSB together with the sulfate-reducing bacterium Desulfocapsa thiozymogenes sp. form stable aggregates in the lake, which represent small microenvironments with an internal sulphur cycle. Eukaryotic primary producers in the anoxic zones are dominated by Cryptomonas phaseolus...

Africa and Arab Gulf states : divergent development paths and prospects for convergence

OpenAIRE

Fofack, Hippolyte

2009-01-01

In spite of the similarities between Sub-Saharan Africa and the Arab Gulf region (Gulf Cooperation Council states), development policies implemented in these two regions of the world have produced markedly different and even divergent outcomes. While Gulf Cooperation Council states have drawn on hydrocarbon revenues to dramatically transform their economic landscape, Sub-Saharan African co...

Gulf war illness--better, worse, or just the same? A cohort study.

Science.gov (United States)

Hotopf, Matthew; David, Anthony S; Hull, Lisa; Nikalaou, Vasilis; Unwin, Catherine; Wessely, Simon

2003-12-13

Firstly, to describe changes in the health of Gulf war veterans studied in a previous occupational cohort study and to compare outcome with comparable non-deployed military personnel. Secondly, to determine whether differences in prevalence between Gulf veterans and controls at follow up can be explained by greater persistence or greater incidence of disorders. Occupational cohort study in the form of a postal survey. Military personnel who served in the 1991 Persian Gulf war; personnel who served on peacekeeping duties to Bosnia; military personnel who were deployed elsewhere ("Era" controls). All participants had responded to a previous survey. United Kingdom. Self reported fatigue measured on the Chalder fatigue scale; psychological distress measured on the general health questionnaire, physical functioning and health perception on the SF-36; and a count of physical symptoms. Gulf war veterans experienced a modest reduction in prevalence of fatigue (48.8% at stage 1, 43.4% at stage 2) and psychological distress (40.0% stage 1, 37.1% stage 2) but a slight worsening of physical functioning on the SF-36 (90.3 stage 1, 88.7 stage 2). Compared with the other cohorts Gulf veterans continued to experience poorer health on all outcomes, although physical functioning also declined in Bosnia veterans. Era controls showed both lower incidence of fatigue than Gulf veterans, and both comparison groups showed less persistence of fatigue compared with Gulf veterans. Gulf war veterans remain a group with many symptoms of ill health. The excess of illness at follow up is explained by both higher incidence and greater persistence of symptoms.

Recent lake ice-out phenology within and among lake districts of Alaska, U.S.A.

Science.gov (United States)

Arp, Christopher D.; Jones, Benjamin M.; Grosse, Guido

2013-01-01

The timing of ice-out in high latitudes is a fundamental threshold for lake ecosystems and an indicator of climate change. In lake-rich regions, the loss of ice cover also plays a key role in landscape and climatic processes. Thus, there is a need to understand lake ice phenology at multiple scales. In this study, we observed ice-out timing on 55 large lakes in 11 lake districts across Alaska from 2007 to 2012 using satellite imagery. Sensor networks in two lake districts validated satellite observations and provided comparison with smaller lakes. Over this 6 yr period, the mean lake ice-out for all lakes was 27 May and ranged from 07 May in Kenai to 06 July in Arctic Coastal Plain lake districts with relatively low inter-annual variability. Approximately 80% of the variation in ice-out timing was explained by the date of 0°C air temperature isotherm and lake area. Shoreline irregularity, watershed area, and river connectivity explained additional variation in some districts. Coherence in ice-out timing within the lakes of each district was consistently strong over this 6 yr period, ranging from r-values of 0.5 to 0.9. Inter-district analysis of coherence also showed synchronous ice-out patterns with the exception of the two arctic coastal districts where ice-out occurs later (June–July) and climatology is sea-ice influenced. These patterns of lake ice phenology provide a spatially extensive baseline describing short-term temporal variability, which will help decipher longer term trends in ice phenology and aid in representing the role of lake ice in land and climate models in northern landscapes.

33 CFR 162.132 - Connecting waters from Lake Huron to Lake Erie; communications rules.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Connecting waters from Lake Huron to Lake Erie; communications rules. 162.132 Section 162.132 Navigation and Navigable Waters COAST... NAVIGATION REGULATIONS § 162.132 Connecting waters from Lake Huron to Lake Erie; communications rules. (a...

33 CFR 162.140 - Connecting waters from Lake Huron to Lake Erie; miscellaneous rules.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Connecting waters from Lake Huron to Lake Erie; miscellaneous rules. 162.140 Section 162.140 Navigation and Navigable Waters COAST... NAVIGATION REGULATIONS § 162.140 Connecting waters from Lake Huron to Lake Erie; miscellaneous rules. (a...

Real-estate lakes

Science.gov (United States)

Rickert, David A.; Spieker, Andrew Maute

1971-01-01

Since the dawn of civilization waterfront land has been an irresistible attraction to man. Throughout history he has sought out locations fronting on oceans, rivers, and lakes. Originally sought for proximity .to water supply and transportation, such locations are now sought more for their esthetic qualities and for recreation. Usable natural waterfront property is limited, however, and the more desirable sites in many of our urban areas have already been taken. The lack of available waterfront sites has led to the creation of many artificial bodies of water. The rapid suburbanization that has characterized urban growth in America since the end of World War II, together with increasing affluence and le-isure time, has created a ready market for waterfront property. Accordingly, lake-centered subdivisions and developments dot the suburban landscape in many of our major urban areas. Literally thousands of lakes surrounded by homes have materialized during this period of rapid growth. Recently, several "new town" communities have been planned around this lake-centered concept. A lake can be either an asset or a liaoility to a community. A clean, clear, attractively landscaped lake is a definite asset, whereas a weed-choked, foul-smelling mudhole is a distinct liability. The urban environment poses both problems and imaginative opportunities in the development of lakes. Creation of a lake causes changes in all aspects of the environment. Hydrologic systems and ecological patterns are usually most severely altered. The developer should be aware of the potential changes; it is not sufficient merely to build a dam across a stream or to dig a hole in the ground. Development of Gl a successful lake requires careful planning for site selection and design, followed by thorough and cc ntinual management. The purpose of this report is to describe the characteristics of real-estate lakes, to pinpoint potential pmblems, and to suggest possible planning and management guidelines

Lake Morphometry for NHD Lakes in California Region 18 HUC

Data.gov (United States)

U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

Lake Morphometry for NHD Lakes in Tennessee Region 6 HUC

Data.gov (United States)

U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

Lake Morphometry for NHD Lakes in Ohio Region 5 HUC

Data.gov (United States)

U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

Bathymetry of Lake Ontario

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lake Ontario has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and geophysical data and make it more...

Bathymetry of Lake Michigan

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lake Michigan has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and geophysical data and make it more...

Bathymetry of Lake Superior

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lake Superior has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and geophysical data and make it more...

Bathymetry of Lake Huron

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lake Huron has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and geophysical data and make it more...

Circulation and sedimentation in a tidal-influenced fjord lake: Lake McKerrow, New Zealand

Science.gov (United States)

Pickrill, R. A.; Irwin, J.; Shakespeare, B. S.

1981-01-01

Lake McKerrow is a tide-influenced fjord lake, separated from the open sea by a Holocene barrier spit. Fresh, oxygenated waters of the epilimnion overlie saline, deoxygenated waters of the hypolimnion. During winter, water from the Upper Hollyford River interflows along the pycnocline, depositing coarse silt on the steep delta and transporting finer sediment down-lake. An extensive sub-lacustrine channel system on the foreset delta slope is possibly maintained by turbidity currents. Saline waters of the hypolimnion are periodically replenished. During high tides and low lake levels saline water flows into the lake and downslope into the lake basin as a density current in a well defined channel.

Hydrothermal Petroleum in Active Continental Rift: Lake Chapala, Western Mexico, Initial Results.

Science.gov (United States)

Zarate-del Valle, P. F.; Simoneit, B. R.; Ramirez-Sanchez, H. U.

2003-12-01

Lake Chapala in western Mexico is located partially in the Citala Rift, which belongs to the well-known neotectonic Jalisco continental triple junction. The region is characterized by active volcanism (Ceboruco, Volcan de Fuego), tectonic (1995 earthquake, M=8, 40-50 mm to SW) and hydrothermal (San Juan Cosala & Villa Corona spas and La Calera sinter deposit) activities. Hydrothermal petroleum has been described in active continental rift (East African Rift) and marine spreading zones (Guaymas Basin, Gulf of California). In 1868 the Mexican local press reported that manifestations of bitumen were appearing in front of the Columba Cap on the mid south shore of Lake Chapala. This bitumen is linked to the lake bottom and when the water level decreases sufficiently it is possible to access these tar bodies as islands. Because of these manifestations the Mexican oil company (PEMEX) drilled an exploration well (2,348m) at Tizapan El Alto without success. Hydrothermal activity is evident in the tar island zone as three in-shore thermal springs (26.8 m depth, 48.5° C, pH 7.8 and oriented N-S). The preliminary analyses by GC-MS of the tar from these islands indicate hydrothermal petroleum derived from lake sedimentary organic matter, generated at low temperatures (150° -200° C). The tars contain no n-alkanes, no PAH or other aromatics, but a major UCM of branched and cyclic hydrocarbons and mature biomarkers derived from lacustrine biota. The biomarkers consist of mainly 17α (H),21β (H)-hopanes ranging from C27 to C34 (no C28), gammacerane, tricyclic terpanes (C20-C26), carotane and its cracking products, and drimanes (C14-C16). The biomarker composition indicates an organic matter source from bacteria and algae, typical of lacustrine ecosystems. 14C dating of samples from two tar islands yielded ages exceeding 40 kyrs, i.e., old carbon from hydrothermal/tectonic remobilization of bitumen from deeper horizons to the surface. The occurrence of hydrothermal petroleum in

33 CFR 162.130 - Connecting waters from Lake Huron to Lake Erie; general rules.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Connecting waters from Lake Huron to Lake Erie; general rules. 162.130 Section 162.130 Navigation and Navigable Waters COAST GUARD... REGULATIONS § 162.130 Connecting waters from Lake Huron to Lake Erie; general rules. (a) Purpose. The...

Great Lakes Restoration Initiative Great Lakes Mussel Watch(2009-2014)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Following the inception of the Great Lakes Restoration Initiative (GLRI) to address the significant environmental issues plaguing the Great Lakes region, the...

Gulf Arab women's transition to motherhood.

Science.gov (United States)

Missal, Bernita

2013-01-01

This paper is a report of the findings of a study of Gulf Arab women's perspectives of the transition to motherhood. Transition to motherhood is a universal phenomenon in which every culture has its own expectations and varying supports for women moving through this transition. International studies have provided models or categories of maternal responses related to cultural aspects of transition to motherhood. However, no known research has focused on transition to motherhood among Gulf Arab women. In the initial cohort seventeen first time Gulf Arab mothers in the United Arab Emirates were interviewed during the following three times: before childbirth, two-four weeks after childbirth, and forty-days after childbirth. A second cohort of seventeen first time new mothers was interviewed after childbirth in Sultanate of Oman. Four patterns were identified as indicators of change as women transitioned into motherhood: 1) Women's personal transition: women changed from feeling of freedom to feeling of dependency to self-confidence. 2) Mother/baby relationships: women changed from fear, anxiety, and uncertainty to feelings of care and confidence. 3) Family influences: women experienced family support to being integrated and feeling respected by family. 4) Cultural/religious beliefs and practices: women felt they were initially observers of culture, to experiencing cultural/religious beliefs and practices. This was followed by accomplishment in childbearing and childrearing practices. As Gulf Arab new mothers made the transition to motherhood, four implications for international nursing practice emerged: 1) patient teaching to help relieve anxiety, fears, and uncertainty, 2) facilitation of mother/baby relationships, 3) family-centered care, and 4) the importance of cultural/religious beliefs and practices to new mothers.

33 CFR 162.134 - Connecting waters from Lake Huron to Lake Erie; traffic rules.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Connecting waters from Lake Huron to Lake Erie; traffic rules. 162.134 Section 162.134 Navigation and Navigable Waters COAST GUARD... REGULATIONS § 162.134 Connecting waters from Lake Huron to Lake Erie; traffic rules. (a) Detroit River. The...

33 CFR 162.138 - Connecting waters from Lake Huron to Lake Erie; speed rules.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Connecting waters from Lake Huron to Lake Erie; speed rules. 162.138 Section 162.138 Navigation and Navigable Waters COAST GUARD... REGULATIONS § 162.138 Connecting waters from Lake Huron to Lake Erie; speed rules. (a) Maximum speed limit for...

33 CFR 162.136 - Connecting waters from Lake Huron to Lake Erie; anchorage grounds.

Science.gov (United States)

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Connecting waters from Lake Huron to Lake Erie; anchorage grounds. 162.136 Section 162.136 Navigation and Navigable Waters COAST GUARD... REGULATIONS § 162.136 Connecting waters from Lake Huron to Lake Erie; anchorage grounds. (a) In the Detroit...

Limnology of Botos Lake, a tropical crater lake in Costa Rica.

Science.gov (United States)

Umaña, G

2001-12-01

Botos Lake, located at the Poas Volcano complex (Costa Rica) was sampled eight times from 1994 to 1996 for physicochemical conditions of the water column and phytoplanktonic community composition. Depth was measured at fixed intervals in several transects across the lake to determine its main morphometric characteristics. The lake has an outlet to the north. It is located 2580 m above sea level and is shallow, with a mean depth of 1.8 m and a relative depth of 2.42 (surface area 10.33 ha, estimated volume 47.3 hm3). The lake showed an isothermal water column in all occasions, but it heats and cools completely according to weather fluctuations. Water transparency reached the bottom on most occasions (> 9 m). The results support the idea that the lake is polymictic and oligotrophic. The lake has at least 23 species of planktonic algae, but it was always dominated by dinoflagellates, especially Peridinium inconspicuum. The shore line is populated by a sparse population of Isoetes sp. and Eleocharis sp. mainly in the northern shore where the bottom has a gentle slope and the forest does not reach the shore.

On the Loop Current Penetration into the Gulf of Mexico

Science.gov (United States)

Weisberg, Robert H.; Liu, Yonggang

2017-12-01

The Gulf of Mexico Loop Current generally intrudes some distance into the Gulf of Mexico before shedding an anticyclonic eddy and retreating back to its more direct entry to exit pathway. The control of this aperiodic process remains only partially known. Here we describe the evolution of the Loop Current throughout the era of satellite altimetry, and offer a mechanistic hypothesis on Loop Current intrusion. As a complement to the known effects of Loop Current forcing on the west Florida shelf circulation, we argue that the west Florida shelf, in turn, impacts the Loop Current evolution. A Self-Organizing Map analysis shows that anomalous northward penetrations of the Loop Current into the Gulf of Mexico occur when the eastern side of Loop Current is positioned west from the southwest corner of the west Florida shelf, whereas the more direct inflow to outflow route occurs when the eastern side of the Loop Current comes in contact with the southwest corner of the west Florida shelf. In essence, we argue that the west Florida shelf anchors the Loop Current in its direct path configuration and that farther northward penetration into the Gulf of Mexico occurs when such anchoring is released. To test of this hypothesis heuristically, we estimate that the dissipation and buoyancy work due to known Loop Current forcing of the west Florida shelf circulation (when in contact with the southwest corner) may exceed the pressure work required for the Loop Current to advance against the ambient Gulf of Mexico fluid.Plain Language SummaryThe Gulf of Mexico Loop Current may intrude far into the Gulf of Mexico or take a more direct entry to exit pathway. Such Loop Current behaviors are described using remote observations by satellites, and a heuristic hypothesis on the control of Loop Current intrusion is presented. We argue that energy dissipation and buoyancy work by the west Florida shelf circulation, when the Loop Current contacts the southwest corner of the west Florida shelf

Nekton from Fishery-Independent Trawl Samples in U.S. Gulf of Mexico Estuaries: A Comparative Assessment of Gulf Estuarine Systems (CAGES), 1973-2007 (NODC Accession 0115183)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The purpose of CAGES (Comparative Assessment of Gulf Estuarine Systems) is to compile the fishery independent data from five Gulf States into a database to more...

Gulf Coast Clean Energy Application Center

Energy Technology Data Exchange (ETDEWEB)

Dillingham, Gavin [Houston Advanced Research Center, TX (United States)

2013-09-30

The Gulf Coast Clean Energy Application Center was initiated to significantly improve market and regulatory conditions for the implementation of combined heat and power technologies. The GC CEAC was responsible for the development of CHP in Texas, Louisiana and Oklahoma. Through this program we employed a variety of outreach and education techniques, developed and deployed assessment tools and conducted market assessments. These efforts resulted in the growth of the combined heat and power market in the Gulf Coast region with a realization of more efficient energy generation, reduced emissions and a more resilient infrastructure. Specific t research, we did not formally investigate any techniques with any formal research design or methodology.

76 FR 41766 - Gulf of Mexico Fishery Management Council; Public Meeting

Science.gov (United States)

2011-07-15

... group Spanish mackerel, and Gulf group cobia. It also contains measures to remove cero, little tunny... separate cobia into Atlantic and Gulf migratory groups. Similar measures are being proposed for the...

75 FR 34934 - Safety Zone; Fireworks for the Virginia Lake Festival, Buggs Island Lake, Clarksville, VA

Science.gov (United States)

2010-06-21

...-AA00 Safety Zone; Fireworks for the Virginia Lake Festival, Buggs Island Lake, Clarksville, VA AGENCY... Fireworks for the Virginia Lake Festival event. This action is intended to restrict vessel traffic movement... Virginia Lake Festival, Buggs Island Lake, Clarksville, VA (a) Regulated Area. The following area is a...

Holocene lake-level fluctuations of Lake Aricota, Southern Peru

Science.gov (United States)

Placzek, C.; Quade, Jay; Betancourt, J.L.

2001-01-01

Lacustrine deposits exposed around Lake Aricota, Peru (17?? 22???S), a 7.5-km2 lake dammed by debris flows, provide a middle to late Holocene record of lake-level fluctuations. Chronological context for shoreline deposits was obtained from radiocarbon dating of vascular plant remains and other datable material with minimal 14C reservoir effects (Titicaca (16?? S), which is only 130 km to the northeast and shares a similar climatology. Comparisons with other marine and terrestrial records highlight emerging contradictions over the nature of mid-Holocene climate in the central Andes. ?? 2001 University of Washington.

77 FR 59185 - Gulf of Mexico Citizen Advisory Committee; Notice of Charter Renewal

Science.gov (United States)

2012-09-26

... ENVIRONMENTAL PROTECTION AGENCY [FRL-9734-9] Gulf of Mexico Citizen Advisory Committee; Notice of... with the provisions of the Federal Advisory Committee Act (FACA), 5 U.S.C. App.2, the Gulf of Mexico... the water quality and living resources of the Gulf of Mexico. FOR FURTHER INFORMATION CONTACT...

Gulf war illness—better, worse, or just the same? A cohort study

Science.gov (United States)

Hotopf, Matthew; David, Anthony S; Hull, Lisa; Nikalaou, Vasilis; Unwin, Catherine; Wessely, Simon

2003-01-01

Objectives Firstly, to describe changes in the health of Gulf war veterans studied in a previous occupational cohort study and to compare outcome with comparable non-deployed military personnel. Secondly, to determine whether differences in prevalence between Gulf veterans and controls at follow up can be explained by greater persistence or greater incidence of disorders. Design Occupational cohort study in the form of a postal survey. Participants Military personnel who served in the 1991 Persian Gulf war; personnel who served on peacekeeping duties to Bosnia; military personnel who were deployed elsewhere (“Era” controls). All participants had responded to a previous survey. Setting United Kingdom. Main outcome measures Self reported fatigue measured on the Chalder fatigue scale; psychological distress measured on the general health questionnaire, physical functioning and health perception on the SF-36; and a count of physical symptoms. Results Gulf war veterans experienced a modest reduction in prevalence of fatigue (48.8% at stage 1, 43.4% at stage 2) and psychological distress (40.0% stage 1, 37.1% stage 2) but a slight worsening of physical functioning on the SF-36 (90.3 stage 1, 88.7 stage 2). Compared with the other cohorts Gulf veterans continued to experience poorer health on all outcomes, although physical functioning also declined in Bosnia veterans. Era controls showed both lower incidence of fatigue than Gulf veterans, and both comparison groups showed less persistence of fatigue compared with Gulf veterans. Conclusions Gulf war veterans remain a group with many symptoms of ill health. The excess of illness at follow up is explained by both higher incidence and greater persistence of symptoms. PMID:14670878

Gulf War Illness and the Health of Gulf War Veterans

Science.gov (United States)

2008-11-01

after his return.432 Seventy- five Gulf War personnel were hospitalized for chicken pox during deployment.1431 Only a few cases of viral hepatitis were...and independent of circulating uranium levels. Of particular interest are findings from an ongoing study at the University of New Mexico indicating that...periods, can produce chronic neurological or behavioral effects. The New Mexico study is an important example of a particularly relevant approach

Gulf digs in to tap a major uranium orebody

International Nuclear Information System (INIS)

Jackson, D.

1977-01-01

The progress and future plans of Gulf Mineral Resources Co. for tapping and developing a major uranium orebody via two concrete-lined shafts in the Grants uranium mineral belt in New Mexico are discussed. The mineralogy of the Grants belt is discussed as it relates to the Gulf development project. Numerous pictures of the operation are included

Gulf of Mexico Sales 142 and 143: Central and western planning areas

International Nuclear Information System (INIS)

1992-11-01

This environmental impact statement (EIS) addresses two proposed Federal actions, lease Sales 142 and 143, that will offer for lease Gulf of Mexico Outer Continental Shelf (OCS) areas that may contain economically recoverable oil and gas resources. The lease sales are proposed for 1993 and include lease blocks in the Central Gulf of Mexico Planning Area (CPA) and Western Gulf of Mexico Planning Area (WPA). Up to 10,099 blocks will be available for lease under the two proposed actions; only a small percentage is expected to be actually leased. On average, 401 blocks in the Central Gulf and 264 blocks in the Western Gulf have been leased in individual Gulf of Mexico OCS lease sales since 1984. Of the blocks that will be leased as a result of the two proposed actions, only a portion will be drilled and result in subsequent production. The scoping process was used to obtain information and comments on the proposed actions and the potential environmental effects from diverse interests, including the affected States, Federal agencies, the petroleum industry, environmental and public interest groups, and concerned individuals. This volume, Volume 2, reports on impacts from Sales 142 and 143

Stable isotope and hydrogeochemical studies of Beaver Lake and Radok Lake, MacRobertson Land, East Antarctica

International Nuclear Information System (INIS)

Wand, U.; Hermichen, W.D.

1988-01-01

Beaver Lake and Radok Lake, the largest known epishelf lake and the deepest freshwater lake on the Antarctic continent, respectively, were isotopically (δ 2 H, δ 18 O) and hydrogeochemically studied. Radok Lake is an isothermal and nonstratified, i.e. homogeneous water body, while Beaver Lake is stratified with respect to temperature, salinity and isotopic composition. The results for the latter attest to freshwater (derived from snow and glacier melt) overlying seawater. (author)

Sediment dispersal in the macro tidal Gulf of Kachchh, India

Digital Repository Service at National Institute of Oceanography (India)

Chauhan, O.S.

of the inner gulf is marked with U and V shaped cuttings extending in the parallel clays, deposited in an earlier phase of deposition. In the outer gulf, there exists a palaeo-channel, buried under 18 m thick sediments (in the central region). Existence...

33 CFR 166.200 - Shipping safety fairways and anchorage areas, Gulf of Mexico.

Science.gov (United States)

2010-07-01

... anchorage areas, Gulf of Mexico. 166.200 Section 166.200 Navigation and Navigable Waters COAST GUARD... the erection of structures therein to provide safe approaches through oil fields in the Gulf of Mexico... for Fairway Anchorages in the Gulf of Mexico. Structures may be placed within an area designated as a...

Energy partnership: Israel and the Persian Gulf

International Nuclear Information System (INIS)

Bahgat, G.

2005-01-01

In the early 2003, American troops toppled the regime of Saddam Hussein in Iraq. Few weeks later, President Bush introduced his vision to solve the Arab-Israeli conflict in what is known as the 'road map'. These interrelated developments confirm the connection between the two Middle-Eastern sub-systems--the Persian Gulf and the Levant and provide an opportunity to achieve a comprehensive peace. Regional economic cooperation is seen as the sine qua non of a durable peace. This study examines the potential for an energy partnership between the Persian Gulf hydrocarbon producers and Israel

Energy partnership: Israel and the Persian Gulf

International Nuclear Information System (INIS)

Bahgat, G.

2005-01-01

In early 2003, American troops toppled the regime of Saddam Hussein in Iraq. Few weeks later, President Bush introduced his vision to solve the Arab-Israeli conflict in what is known as the ''road map''. These interrelated developments confirm the connection between the two Middle-Eastern sub-systems-the Persian Gulf and the Levant and provide an opportunity to achieve a comprehensive peace. Regional economic cooperation is seen as the sine qua non of a durable peace. This study examines the potential for an energy partnership between the Persian Gulf hydrocarbon producers and Israel. (author)

Gulf International Conference on Applied Mathematics 2013

CERN Document Server

Advances in Applied Mathematics

2014-01-01

This volume contains contributions from the Gulf International Conference in Applied Mathematics, held at the Gulf University for Science & Technology. The proceedings reflects the three major themes of the conference. The first of these was mathematical biology, including a keynote address by Professor Philip Maini. The second theme was computational science/numerical analysis, including a keynote address by Professor Grigorii Shishkin. The conference also addressed more general applications topics, with papers in business applications, fluid mechanics, optimization, scheduling problems, and engineering applications, as well as a keynote by Professor Ali Nayfeh.

Lake Generated Microseisms at Yellowstone Lake as a Record of Ice Phenology

Science.gov (United States)

Mohd Mokhdhari, A. A.; Koper, K. D.; Burlacu, R.

2017-12-01

It has recently been shown that wave action in lakes produces microseisms, which generate noise peaks in the period range of 0.8-1.2 s as recorded by nearby seismic stations. Such noise peaks have been observed at seven seismic stations (H17A, LKWY, B208, B944, YTP, YLA, and YLT) located within 2 km of the Yellowstone Lake shoreline. Initial work using 2016 data shows that the variations in the microseism signals at Yellowstone Lake correspond with the freezing and thawing of lake ice: the seismic noise occurs more frequently in the spring, summer, and fall, and less commonly in the winter. If this can be confirmed, then lake-generated microseisms could provide a consistent measure of the freezing and melting dates of high-latitude lakes in remote areas. The seismic data would then be useful in assessing the effects of climate change on the ice phenology of those lakes. In this work, we analyze continuous seismic data recorded by the seven seismic stations around Yellowstone Lake for the years of 1995 to 2016. We generate probability distribution functions of power spectral density for each station to observe the broad elevation of energy near a period of 1 s. The time dependence of this 1-s seismic noise energy is analyzed by extracting the power spectral density at 1 s from every processed hour. The seismic observations are compared to direct measurements of the dates of ice-out and freeze-up as reported by rangers at Yellowstone National Park. We examine how accurate the seismic data are in recording the freezing and melting of Yellowstone Lake, and how the accuracy changes as a function of the number of stations used. We also examine how sensitive the results are to the particular range of periods that are analyzed.

Gulfs of Suez and Aqaba: New insights from recent satellite-marine potential field data

Science.gov (United States)

Almalki, Khalid A.; Mahmud, Syed A.

2018-01-01

Previous models and interpretations of crustal geometry and the nature of the crust under the Gulfs of Suez and Aqaba have generally been based on a local or small scale and have been limited due to a lack of data. The few studies that present larger scale crustal and uppermost mantle structure were dependent on one type of data with no consideration of other geological and/or geophysical features. Satellite-marine potential field data provide for the first time a full coverage dataset of the Gulfs of Suez and Aqaba as well as the Sinai area at the same scale which allows for a better understanding of crustal domains and geometry and the interplay between tectonic events. To that end, our forward models of magnetic and gravity data constrained by seismic data and available geological information in this area suggest that the crustal domains in the Gulf of Aqaba are more complicated than those in the Gulf of Suez. Our result supports continental rifting under most of the Gulf of Suez and a combination of transitional and continental crusts under the Gulf of Aqaba. Yet, there is no evidence of oceanic segment development in these gulfs. Regardless of oceanic or transitional crust, the models support a link between the Arabia and Sinai plates at the central Gulf of Aqaba. The data also support that Red Sea tectonism has no connection to or influence on both gulfs. The result suggests a continuation of lithological elements from land into the eastern part of the Gulf of Suez. Our synthesis and interpretations may play an important role in the reassessment of the tectonic history and extension of this important rift system.

Modelling the temporal and spatial distribution of ecological variables in Beibu Gulf

Science.gov (United States)

Pan, H.; Huang, L.; Yang, S.; Shi, D.; Pan, W.

2017-12-01

Beibu Gulf is an important semi-enclosed gulf located in northern South China Sea. It is rich in natural resources and its coastal rim is undergoing a rapid economic growth in recent years. Study on the spatial and temporal distribution of ecological variables by the influence of physical and biological processes in Beibu Gulf can provide the theoretical basis for the utilization of resources and environmental protection. Based on the MEC three-dimensional hydrodynamic model, a nutrient-phytoplankton-zooplankton-detritus (NPZD) model was applied to simulate the distribution of ecological variables in Beibu Gulf. The result shows that the ecosystem in Beibu Gulf is significantly influenced by dynamic conditions. In autumn and winter, great amount of nutrient-rich water from western Guangdong coastal area passes through Qiongzhou Strait and flows into Beibu Gulf, with about 108.3×103 t of inorganic nitrogen and 3.7×103 t of phosphate annually, leading to phytoplankton bloom. In summer, most of the nutrients come from rivers so high concentrations of nutrients and chlorophyll-a appear on estuaries. The annual net nutrient inputs from South China Sea into Beibu Gulf are 66.6×103 t for inorganic nitrogen and 4.6×103 t for phosphate. Phytoplankton plays an important role in nutrients' refreshment: a) Absorption by the process of photosynthesis is the biggest nutrient sink. b) Cellular release from dead phytoplankton is the biggest source in inorganic budget, making up for 33.4% of nitrogen consumed by photosynthesis while the process of respiration is the biggest source in phosphate budget, making up for 32.4% of phosphorus consumed by photosynthesis. c) Mineralization from detritus is also a considerable supplement of inorganic nutrients. Overall, biological process has more influence than physical process on the nutrient cycle budget in Beibu Gulf. The comparison of the result with remote sensing and in-situ data indicates that the model is able to simulate the

Monitoring climate signal transfer into the varved lake sediments of Lake Czechowskie, Poland

Science.gov (United States)

Groß-Schmölders, Miriam; Ott, Florian; Brykała, Dariusz; Gierszewski, Piotr; Kaszubski, Michał; Kienel, Ulrike; Brauer, Achim

2015-04-01

In 2012 we started a monitoring program at Lake Czechowskie, Poland, because the lake comprises a long Holocene time series of calcite varves until recent times. The aim of the program is to understand how environmental and climatic conditions influence the hydrological conditions and, ultimately, the sediment deposition processes of the lake. Lake Czechowskie is located in the north of Poland in the Pomeranian Lake District and is part of the national park Tuchola Forest. The landscape and the lake is formed by the glacier retreat after the last glaciation (Weichselian). Lake Czechowskie is a typical hardwater lake and has a length of 1.4 km, an average width of 600 m and a lake surface area of ca 4 km. The maximum depth of 32 m is reached in a rather small hollow in the eastern part of the lake. Two different types of sediment traps provide sediment samples with monthly resolution from different water depths (12m, 26m). In addition, hydrological data including water temperature in different depths, water inflow, throughflow and outflow and the depth of visibility are measured. These data allow to describe strength and duration of lake mixing in spring and autumn and its influence on sedimentation. The sediment samples were analyzed with respect to their dry weight (used to calculate mean daily sediment flux), their inorganic and organic carbon contents, the stable C- and O-isotopes of organic matter and calcite as well as N-isotopes of organic matter. For selected samples dominant diatom taxa are determined. Our first results demonstrate the strong influence of the long winter with ice cover until April in 2013 on the sedimentation. A rapid warming in only 9 days starting on April 9th from -0,3 C° to 15,2 C° resulted in fast ice break-up and a short but intensive lake mixing. In consequence of this short mixing period a strong algal bloom especially of Fragilaria and Crysophycea commenced in April and had its maximum in May. This bloom further induced biogenic

A study of burrow morphology in representative axiidean and gebiidean mud shrimps, from the Persian Gulf and Gulf of Oman, Iran

Directory of Open Access Journals (Sweden)

Vahid Sepahvand

Full Text Available Mud shrimps (formerly Thalassinidea are common burrow dwelling decapod crustaceans in the littoral zone of the Persian Gulf and Gulf of Oman. Their burrow morphology was investigated using foam casting methods. The present study shows that the burrow morphology in Upogebia carinicauda is not consistent and the recorded variations are based on habitat type and some physical characteristics of sediments. Adult burrow morphology in sandy-muddy substrate with shells, and boulder field habitats were Y-shaped and complex burrows of horizontal channels with turning chambers and vertical connections to internal passages or crevices of boulders, respectively. In burrows of U. carinicauda, some narrow passages, connected to the upper part of adult burrows in sandy-muddy habitats, belong to juveniles. Another species, Neocallichirus jousseaumei was found under boulders in sandy-muddy habitats of the Gulf of Oman and Qeshm Island, Persian Gulf. Since this type of habitat is special in some features, no conspicuous ex-current openings (usually obvious as conical mounds of extruded sediment have been observed on the sediment surface; as these were hidden among the boulders surrounded by mixed sand and shells. The only method for observing this type of burrow was to remove the boulders by hand or lever.

78 FR 36309 - Research Advisory Committee on Gulf War Veterans' Illnesses, Notice of Meeting

Science.gov (United States)

2013-06-17

... DEPARTMENT OF VETERANS AFFAIRS Research Advisory Committee on Gulf War Veterans' Illnesses, Notice... Act, 5 U.S.C. App., that the Research Advisory Committee on Gulf War Veterans' Illnesses will meet on... operations during the Gulf War. [[Page 36310

Is Lake Chabot Eutrophic?

Science.gov (United States)

Pellegrini, K.; Logan, J.; Esterlis, P.; Lew, A.; Nguyen, M.

2013-12-01

Introduction/Abstract: Lake Chabot is an integral part of the East Bay watershed that provides habitats for animals and recreation for humans year-round. Lake Chabot has been in danger of eutrophication due to excessive dumping of phosphorous and nitrogen into the water from the fertilizers of nearby golf courses and neighboring houses. If the lake turned out to be eutrophified, it could seriously impact what is currently the standby emergency water supply for many Castro Valley residents. Eutrophication is the excessive richness of nutrients such as nitrogen and phosphorus in a lake, usually as a result of runoff. This buildup of nutrients causes algal blooms. The algae uses up most of the oxygen in the water, and when it dies, it causes the lake to hypoxify. The fish in the lake can't breathe, and consequently suffocate. Other oxygen-dependant aquatic creatures die off as well. Needless to say, the eutrophication of a lake is bad news for the wildlife that lives in or around it. The level of eutrophication in our area in Northern California tends to increase during the late spring/early summer months, so our crew went out and took samples of Lake Chabot on June 2. We focused on the area of the lake where the water enters, known on the map as Honker Bay. We also took readings a ways down in deeper water for comparison's sake. Visually, the lake looked in bad shape. The water was a murky green that glimmered with particulate matter that swirled around the boat as we went by. In the Honker Bay region where we focused our testing, there were reeds bathed in algae that coated the surface of the lake in thick, swirling patterns. Surprisingly enough, however, our test results didn't reveal any extreme levels of phosphorous or nitrogen. They were slightly higher than usual, but not by any significant amount. The levels we found were high enough to stimulate plant and algae growth and promote eutrophication, but not enough to do any severe damage. After a briefing with a

Limnology of Eifel maar lakes

National Research Council Canada - National Science Library

Scharf, Burkhard W; Björk, Sven

1992-01-01

... & morphometry - Physical & chemical characteristics - Calcite precipitation & solution in Lake Laacher See - Investigations using sediment traps in Lake Gemundener Maar - Phytoplankton of Lake Weinfelder Maar...

Investigation of Residence and Travel Times in a Large Floodplain Lake with Complex Lake-River Interactions: Poyang Lake (China

Directory of Open Access Journals (Sweden)

Yunliang Li

2015-04-01

Full Text Available Most biochemical processes and associated water quality in lakes depends on their flushing abilities. The main objective of this study was to investigate the transport time scale in a large floodplain lake, Poyang Lake (China. A 2D hydrodynamic model (MIKE 21 was combined with dye tracer simulations to determine residence and travel times of the lake for various water level variation periods. The results indicate that Poyang Lake exhibits strong but spatially heterogeneous residence times that vary with its highly seasonal water level dynamics. Generally, the average residence times are less than 10 days along the lake’s main flow channels due to the prevailing northward flow pattern; whereas approximately 30 days were estimated during high water level conditions in the summer. The local topographically controlled flow patterns substantially increase the residence time in some bays with high spatial values of six months to one year during all water level variation periods. Depending on changes in the water level regime, the travel times from the pollution sources to the lake outlet during the high and falling water level periods (up to 32 days are four times greater than those under the rising and low water level periods (approximately seven days.

Sexual difference in PCB concentrations of lake trout (Salvelinus namaycush) from Lake Ontario

Science.gov (United States)

Madenjian, Charles P.; Keir, Michael J.; Whittle, D. Michael; Noguchi, George E.

2010-01-01

We determined polychlorinated biphenyl (PCB) concentrations in 61 female lake trout (Salvelinus namaycush) and 71 male lake trout from Lake Ontario (Ontario, Canada and New York, United States). To estimate the expected change in PCB concentration due to spawning, PCB concentrations in gonads and in somatic tissue of lake trout were also determined. In addition, bioenergetics modeling was applied to investigate whether gross growth efficiency (GGE) differed between the sexes. Results showed that, on average, males were 22% higher in PCB concentration than females in Lake Ontario. Results from the PCB determinations of the gonads and somatic tissues revealed that shedding of the gametes led to 3% and 14% increases in PCB concentration for males and females, respectively. Therefore, shedding of the gametes could not explain the higher PCB concentration in male lake trout. According to the bioenergetics modeling results, GGE of males was about 2% higher than adult female GGE, on average. Thus, bioenergetics modeling could not explain the higher PCB concentrations exhibited by the males. Nevertheless, a sexual difference in GGE remained a plausible explanation for the sexual difference in PCB concentrations of the lake trout.

L-Lake macroinvertebrate community

International Nuclear Information System (INIS)

Specht, W.L.

1996-06-01

To characterize the present benthic macroinvertebrate community of L-Lake, Regions 5 and 7 of the reservoir were sampled in September 1995 at the same locations sampled in 1988 and 1989 during the L-Lake monitoring program. The macroinvertebrate community of 1995 is compared to that of 1988 and 1989. The species composition of L-Lake's macroinvertebrate community has changed considerably since 1988-1989, due primarily to maturation of the reservoir ecosystem. L-Lake contains a reasonably diverse macroinvertebrate community that is capable of supporting higher trophic levels, including a diverse assemblage of fish species. The L-Lake macroinvertebrate community is similar to those of many other southeastern reservoirs, and there is no indication that the macroinvertebrate community is perturbed by chemical or physical stressors

L-Lake macroinvertebrate community

Energy Technology Data Exchange (ETDEWEB)

Specht, W.L.

1996-06-01

To characterize the present benthic macroinvertebrate community of L-Lake, Regions 5 and 7 of the reservoir were sampled in September 1995 at the same locations sampled in 1988 and 1989 during the L-Lake monitoring program. The macroinvertebrate community of 1995 is compared to that of 1988 and 1989. The species composition of L-Lake`s macroinvertebrate community has changed considerably since 1988-1989, due primarily to maturation of the reservoir ecosystem. L-Lake contains a reasonably diverse macroinvertebrate community that is capable of supporting higher trophic levels, including a diverse assemblage of fish species. The L-Lake macroinvertebrate community is similar to those of many other southeastern reservoirs, and there is no indication that the macroinvertebrate community is perturbed by chemical or physical stressors.

Subtidal micro and meiobenthic community structure in the Gulf of Kachchh

Digital Repository Service at National Institute of Oceanography (India)

Ingole, B.S.; Goltekar, R.

Community structure of the micro- and meiobenthos of subtidal sediment from the Gulf of Kachchh were investigated during April 2002 (premonsoon season). Sediment samples were collected from 23 stations representing the entire Gulf area. A total...

Tropical cyclone disasters in the Gulf of Thailand

Directory of Open Access Journals (Sweden)

Suphat Vongvisessomjai

2009-07-01

Full Text Available The origin of tropical cyclones in the South China Sea is over a vast deep sea, southeast of the Philippines. The severetropical cyclones in summer with northerly tracks attack the Philippines, China, Korea and Japan, while the moderate ones inthe rainy season with northwesterly tracks pass Vietnam, Laos and northern Thailand. In October, November and December, the tropical cyclones are weakened and tracks shift to a lower latitude passing the Gulf of Thailand. Tropical cyclone disasters in the Gulf of Thailand due to strong winds causing storm surges and big waves or heavy rainfall over high mountains in causing floods and land slides result in moderate damages and casualties. Analyses are made of six decades of data of tropical cyclones from 1951-2006 having averaged numbers of 3 and 13 in Thailand and the South China Sea respectively. Detailed calculation of surges and wave heights of the 5 disastrous tropical cyclones in the Gulf of Thailand reveal that the Upper Gulf of Thailand with a limited fetch length of about 100 km in north/south direction and about 100 km width in the east/west direction, resulted in a limited maximum wave height of 2.3-2.5 m and maximum storm surge height of 1.2 m generated by Typhoon Vae (1952, while the east coast, with longer fetch lengthbut still limited by the existence of its shoreline, resulted in an increased maximum wave height of 4 m and maximum storm surge height of 0.6 m in the Upper Gulf of Thailand generated by Typhoon Linda (1997. These are the Probable Maximum Cyclones here.The southern shoreline, with unlimited fetch length on the east by tropical cyclones approaching from the South China Sea, generated maximum wave height of 6-11 m by Typhoon Gay (1989, resulting in more casualties and damages. Note that storm surges on the southern shorelines with steep slopes are small due to the short distance of shallow shorelines in receiving wind stresses for piling up sea levels. These disasters can be

The April 2007 earthquake swarm near Lake Trichonis and implications for active tectonics in western Greece

Science.gov (United States)

Kiratzi, A.; Sokos, E.; Ganas, A.; Tselentis, A.; Benetatos, C.; Roumelioti, Z.; Serpetsidaki, A.; Andriopoulos, G.; Galanis, O.; Petrou, P.

2008-06-01

We investigate the properties of the April 2007 earthquake swarm (Mw 5.2) which occurred at the vicinity of Lake Trichonis (western Greece). First we relocated the earthquakes, using P- and S-wave arrivals to the stations of the Hellenic Unified Seismic Network (HUSN), and then we applied moment tensor inversion to regional broad-band waveforms to obtain the focal mechanisms of the strongest events of the 2007 swarm. The relocated epicentres, cluster along the eastern banks of the lake, and follow a distinct NNW-ESE trend. The previous strong sequence close to Lake Trichonis occurred in June-December 1975. We applied teleseismic body waveform inversion, to obtain the focal mechanism solution of the strongest earthquake of this sequence, i.e. the 31 December 1975 (Mw 6.0) event. Our results indicate that: a) the 31 December 1975 Mw 6.0 event was produced by a NW-SE normal fault, dipping to the NE, with considerable sinistral strike-slip component; we relocated its epicentre: i) using phase data reported to ISC and its coordinates are 38.486°N, 21.661°E; ii) using the available macroseismic data, and the coordinates of the macroseismic epicentre are 38.49°N, 21.63°E, close to the strongly affected village of Kato Makrinou; b) the earthquakes of the 2007 swarm indicate a NNW-SSE strike for the activated main structure, parallel to the eastern banks of Lake Trichonis, dipping to the NE and characterized by mainly normal faulting, occasionally combined with sinistral strike-slip component. The 2007 earthquake swarm did not rupture the well documented E-W striking Trichonis normal fault that bounds the southern flank of the lake, but on the contrary it is due to rupture of a NW-SE normal fault that strikes at a ˜ 45° angle to the Trichonis fault. The left-lateral component of faulting is mapped for the first time to the north of the Gulf of Patras which was previously regarded as the boundary for strike-slip motions in western Greece. This result signifies the

Water-quality and lake-stage data for Wisconsin lakes, water years 2012–2013

Science.gov (United States)

Manteufel, S. Bridgett; Robertson, Dale M.

2017-05-25

IntroductionThe U.S. Geological Survey (USGS), in cooperation with local and other agencies, collects data at selected lakes throughout Wisconsin. These data, accumulated over many years, provide a data base for developing an improved understanding of the water quality of lakes. To make these data available to interested parties outside the USGS, the data are published annually in this report series. The locations of water-quality and lake-stage stations in Wisconsin for water year 2012 are shown in figure 1. A water year is the 12-month period from October 1 through September 30. It is designated by the calendar year in which it ends. Thus, the period October 1, 2011 through September 30, 2012, is called “water year 2012.”The purpose of this report is to provide information about the chemical and physical characteristics of Wisconsin lakes. Data that have been collected at specific lakes, and information to aid in the interpretation of those data, are included in this report. Data collected include measurements of in-lake water quality and lake stage. Time series of Secchi depths, surface total phosphorus and chlorophyll a concentrations collected during non-frozen periods are included for all lakes. Graphs of vertical profiles of temperature, dissolved oxygen, pH, and specific conductance are included for sites where these parameters were measured. Descriptive information for each lake includes: location of the lake, area of the lake’s watershed, period for which data are available, revisions to previously published records, and pertinent remarks. Additional data, such as streamflow and water quality in tributary and outlet streams of some of the lakes, are published online at http://nwis.waterdata.usgs.gov/wi/nwis.Water-resources data, including stage and discharge data at most streamflow-gaging stations, are available online. The Wisconsin Water Science Center’s home page is at https://www.usgs.gov/centers/wisconsin-water-science-center. Information on

Hydrochemical determination of source water contributions to Lake Lungo and Lake Ripasottile (central Italy

Directory of Open Access Journals (Sweden)

Claire Archer

2016-12-01

Full Text Available Lake Lungo and Lake Ripasottile are two shallow (4-5 m lakes located in the Rieti Basin, central Italy, that have been described previously as surface outcroppings of the groundwater table. In this work, the two lakes as well as springs and rivers that represent their potential source waters are characterized physio-chemically and isotopically, using a combination of environmental tracers. Temperature and pH were measured and water samples were analyzed for alkalinity, major ion concentration, and stable isotope (δ2H, δ18O, δ13C of dissolved inorganic carbon, and δ34S and δ18O of sulfate composition.  Chemical data were also investigated in terms of local meteorological data (air temperature, precipitation to determine the sensitivity of lake parameters to changes in the surrounding environment. Groundwater represented by samples taken from Santa Susanna Spring was shown to be distinct with SO42- and Mg2+ content of 270 and 29 mg/L, respectively, and heavy sulfate isotopic composition (δ34S=15.2 ‰ and δ18O=10‰. Outflow from the Santa Susanna Spring enters Lake Ripasottile via a canal and both spring and lake water exhibits the same chemical distinctions and comparatively low seasonal variability. Major ion concentrations in Lake Lungo are similar to the Vicenna Riara Spring and are interpreted to represent the groundwater locally recharged within the plain. The δ13CDIC exhibit the same groupings as the other chemical parameters, providing supporting evidence of the source relationships. Lake Lungo exhibited exceptional ranges of δ13CDIC (±5 ‰ and δ2H, δ18O (±5 ‰ and ±7 ‰, respectively, attributed to sensitivity to seasonal changes. The hydrochemistry results, particularly major ion data, highlight how the two lakes, though geographically and morphologically similar, represent distinct hydrochemical facies. These data also show a different response in each lake to temperature and precipitation patterns in the basin that

Lake trout (Salvelinus namaycush) suppression for bull trout (Salvelinus confluentus) recovery in Flathead Lake, Montana, North America

Science.gov (United States)

Hansen, Michael J.; Hansen, Barry S; Beauchamp, David A.

2016-01-01

Non-native lake trout Salvelinus namaycush displaced native bull trout Salvelinus confluentus in Flathead Lake, Montana, USA, after 1984, when Mysis diluviana became abundant following its introduction in upstream lakes in 1968–1976. We developed a simulation model to determine the fishing mortality rate on lake trout that would enable bull trout recovery. Model simulations indicated that suppression of adult lake trout by 75% from current abundance would reduce predation on bull trout by 90%. Current removals of lake trout through incentivized fishing contests has not been sufficient to suppress lake trout abundance estimated by mark-recapture or indexed by stratified-random gill netting. In contrast, size structure, body condition, mortality, and maturity are changing consistent with a density-dependent reduction in lake trout abundance. Population modeling indicated total fishing effort would need to increase 3-fold to reduce adult lake trout population density by 75%. We conclude that increased fishing effort would suppress lake trout population density and predation on juvenile bull trout, and thereby enable higher abundance of adult bull trout in Flathead Lake and its tributaries.

Lake Morphometry for NHD Lakes in Upper Colorado Region 14 HUC

Data.gov (United States)

U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

Lake Morphometry for NHD Lakes in North East Region 1 HUC

Data.gov (United States)

U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

Lake Morphometry for NHD Lakes in Lower Colorado Region 15 HUC

Data.gov (United States)

U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

Lake Morphometry for NHD Lakes in Upper Mississippi Region 7 HUC

Data.gov (United States)

U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

Lake Morphometry for NHD Lakes in Rio Grande Region 13 HUC

Data.gov (United States)

U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

Lake Morphometry for NHD Lakes in Pacific Northwest Region 17 HUC

Data.gov (United States)

U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

Lake Morphometry for NHD Lakes in Lower Mississippi Region 8 HUC

Data.gov (United States)

U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

75 FR 22620 - Upper Klamath, Lower Klamath, Tule Lake, Bear Valley, and Clear Lake National Wildlife Refuges...

Science.gov (United States)

2010-04-29

...] Upper Klamath, Lower Klamath, Tule Lake, Bear Valley, and Clear Lake National Wildlife Refuges, Klamath..., Bear Valley, and Clear Lake National Wildlife Refuges (Refuges) located in Klamath County, Oregon, and..., Tule Lake, Bear Valley, and Clear Lake Refuges located in Klamath County, Oregon, and Siskiyou and...

The Key Lake project

International Nuclear Information System (INIS)

1991-01-01

Key Lake is located in the Athabasca sand stone basin, 640 kilometers north of Saskatoon, Saskatchewan, Canada. The three sources of ore at Key Lake contain 70 100 tonnes of uranium. Features of the Key Lake Project were described under the key headings: work force, mining, mill process, tailings storage, permanent camp, environmental features, worker health and safety, and economic benefits. Appendices covering the historical background, construction projects, comparisons of western world mines, mining statistics, Northern Saskatchewan surface lease, and Key Lake development and regulatory agencies were included

Gulf of Mexico Sales 142 and 143: Central and western planning areas

International Nuclear Information System (INIS)

1992-11-01

This environmental impact statement (EIS) addresses two proposed Federal actions, lease Sales 142 and 143, that will offer for lease Gulf of Mexico Outer Continental Shelf (OCS) areas that may contain economically recoverable oil and gas resources. The lease sales are proposed for 1993 and include lease blocks in the Central Gulf of Mexico Planning Area (CPA) and Western Gulf of Mexico Planning Area (WPA). Up to 10,099 blocks will be available for lease under the two proposed actions; only a small percentage is expected to be actually leased. On average, 401 blocks in the Central Gulf and 264 blocks in the Western Gulf have been leased in individual Gulf of Mexico OCS lease sales since 1984. Of the blocks that will be leased as a result of the two proposed actions, only a portion will be drilled and result in subsequent production. The scoping process was used to obtain information and comments on the proposed actions and the potential environmental effects from diverse interests, including the affected States, Federal agencies, the petroleum industry, environmental and public interest groups, and concerned individuals. The input from these sources aided in the identification of significant issues, possible alternatives to the proposed actions, and potential mitigating measures

Gulf War veterans' health: medical evaluation of a U.S. cohort.

Science.gov (United States)

Eisen, Seth A; Kang, Han K; Murphy, Frances M; Blanchard, Melvin S; Reda, Domenic J; Henderson, William G; Toomey, Rosemary; Jackson, Leila W; Alpern, Renee; Parks, Becky J; Klimas, Nancy; Hall, Coleen; Pak, Hon S; Hunter, Joyce; Karlinsky, Joel; Battistone, Michael J; Lyons, Michael J

2005-06-07

United States military personnel reported various symptoms after deployment to the Persian Gulf during the 1991 Gulf War. However, the symptoms' long-term prevalence and association with deployment remain controversial. To assess and compare the prevalence of selected medical conditions in a national cohort of deployed and nondeployed Gulf War veterans who were evaluated by direct medical and teledermatologic examinations. A cross-sectional prevalence study performed 10 years after the 1991 Gulf War. Veterans were examined at 1 of 16 Veterans Affairs medical centers. Deployed (n = 1061) and nondeployed (n = 1128) veterans of the 1991 Gulf War. Primary outcome measures included fibromyalgia, the chronic fatigue syndrome, dermatologic conditions, dyspepsia, physical health-related quality of life (Short Form-36 [SF-36]), hypertension, obstructive lung disease, arthralgias, and peripheral neuropathy. Of 12 conditions, only 4 conditions were more prevalent among deployed than nondeployed veterans: fibromyalgia (deployed, 2.0%; nondeployed, 1.2%; odds ratio, 2.32 [95% CI, 1.02 to 5.27]); the chronic fatigue syndrome (deployed, 1.6%; nondeployed 0.1%; odds ratio, 40.6 [CI, 10.2 to 161]); dermatologic conditions (deployed, 34.6%; nondeployed, 26.8%; odds ratio, 1.38 [CI, 1.06 to 1.80]), and dyspepsia (deployed, 9.1%; nondeployed, 6.0%; odds ratio, 1.87 [CI, 1.16 to 2.99]). The mean physical component summary score of the SF-36 for deployed and nondeployed veterans was 49.3 and 50.8, respectively. Relatively low participation rates introduce potential participation bias, and deployment-related illnesses that resolved before the research examination could not, by design, be detected. Ten years after the Gulf War, the physical health of deployed and nondeployed veterans is similar. However, Gulf War deployment is associated with an increased risk for fibromyalgia, the chronic fatigue syndrome, skin conditions, dyspepsia, and a clinically insignificant decrease in the SF-36

Binational collaboration to study Gulf of Mexico's harmful algae

Science.gov (United States)

Soto, Inia; Hu, Chuanmin; Steidinger, Karen; Muller-Karger, Frank; Cannizzaro, Jennifer; Wolny, Jennifer; Cerdeira-Estrada, Sergio; Santamaria-del-Angel, Eduardo; Tafoya-del-Angel, Fausto; Alvarez-Torres, Porfirio; Herrera Silveira, Jorge; Allen, Jeanne

2012-01-01

Blooms of the toxic marine dinoflagellate Karenia brevis cause massive fish kills and other public health and economic problems in coastal waters throughout the Gulf of Mexico [Steidinger, 2009]. These harmful algal blooms (HABs) are a gulf-wide problem that require a synoptic observing system for better serving decision-making needs. The major nutrient sources that initiate and maintain these HABs and the possible connectivity of blooms in different locations are important questions being addressed through new collaborations between Mexican and U.S. researchers and government institutions. These efforts were originally organized under the U.S./Mexico binational partnership for the HABs Observing System (HABSOS), led by the U.S. Environmental Protection Agency's Gulf of Mexico Program (EPAGMP) and several agencies in Veracruz, Mexico, since 2006. In 2010 these efforts were expanded to include other Mexican states and institutions with the integrated assessment and management of the Gulf of Mexico Large Marine Ecosystem (GoMLME) program sponsored by the Global Environment Facility (GEF), the United Nations Industrial Development Organization (UNIDO), the Secretaría de Medio Ambiente y Recursos Naturales (SEMARNAT), and the National Oceanic and Atmospheric Administration (NOAA).

77 FR 64597 - Proposed Information Collection (Survey of Chronic Gastrointestinal Illness in Persian Gulf...

Science.gov (United States)

2012-10-22

... of Chronic Gastrointestinal Illness in Persian Gulf Veterans (Irritable Bowel Syndrome--Diarrhea... information needed to evaluate chronic gastrointestinal disorders in Persian Gulf War Veterans. DATES: Written... Gastrointestinal Illness in Persian Gulf Veterans, VA Form 10-21092c. OMB Control Number: 2900-0742. Type of Review...

77 FR 31071 - Research Advisory Committee on Gulf War Veterans' Illnesses, Notice of Meeting

Science.gov (United States)

2012-05-24

... DEPARTMENT OF VETERANS AFFAIRS Research Advisory Committee on Gulf War Veterans' Illnesses, Notice... Advisory Committee Act) that the Research Advisory Committee on Gulf War Veterans' Illnesses will meet on... Asia theater of operations during the Gulf War. The Committee will review VA program activities related...

75 FR 28686 - Research Advisory Committee on Gulf War Veterans' Illnesses; Notice of Meeting

Science.gov (United States)

2010-05-21

... DEPARTMENT OF VETERANS AFFAIRS Research Advisory Committee on Gulf War Veterans' Illnesses; Notice... Advisory Committee Act) that the Research Advisory Committee on Gulf War Veterans' Illnesses will meet on... Asia theater of operations during the Gulf War. The Committee will review VA program activities related...

76 FR 9407 - Research Advisory Committee on Gulf War Veterans' Illnesses; Notice of Meeting

Science.gov (United States)

2011-02-17

... DEPARTMENT OF VETERANS AFFAIRS Research Advisory Committee on Gulf War Veterans' Illnesses; Notice... Advisory Committee Act) that the Research Advisory Committee on Gulf War Veterans' Illnesses will meet on... Southwest Asia theater of operations during the Gulf War. The Committee will review VA program activities...

75 FR 65405 - Research Advisory Committee on Gulf War Veterans' Illnesses; Notice of Meeting

Science.gov (United States)

2010-10-22

... DEPARTMENT OF VETERANS AFFAIRS Research Advisory Committee on Gulf War Veterans' Illnesses; Notice... Advisory Committee Act) that the Research Advisory Committee on Gulf War Veterans' Illnesses will meet on... Asia theater of operations during the Gulf War. The Committee will review VA program activities related...

Who Benefits from Foreign Universities in the Arab Gulf States?

Science.gov (United States)

Wilkins, Stephen

2011-01-01

The Arab Gulf States are the largest hosts of international branch campuses globally. By increasing higher education capacity in the Arab Gulf States by over 30,000 places, foreign institutions have, through various forms of transnational provision, increased significantly the accessibility of higher education to young people living in these…

38 CFR 21.5053 - Restoration of contributions (Persian Gulf War).

Science.gov (United States)

2010-07-01

... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Restoration of contributions (Persian Gulf War). 21.5053 Section 21.5053 Pensions, Bonuses, and Veterans' Relief DEPARTMENT OF... Assistance Under 38 U.S.C. Chapter 32 Participation § 21.5053 Restoration of contributions (Persian Gulf War...

Palaeolimnological evidence of vulnerability of Lake Neusiedl (Austria) toward climate related changes since the last "vanished-lake" stage.

Science.gov (United States)

Tolotti, Monica; Milan, Manuela; Boscaini, Adriano; Soja, Gerhard; Herzig, Alois

2013-04-01

The palaeolimnological reconstruction of secular evolution of Euroepan Lakes with key socio-economical relevance respect to large (climate change) and local scale (land use, tourism) environmental changes, represents one of the objectives of the project EuLakes (European Lakes Under Environmental Stressors, Supporting lake governance to mitigate the impact of climate change, Reg. N. 2CE243P3), launched in 2010 within the Central European Inititiative. The project consortium comprises lakes of different morphology and prevalent human uses, including the meso-eutrophic Lake Neusiedl, the largest Austrian lake (total area 315 km2), and the westernmost shallow (mean depth 1.2 m) steppe lake of the Euro-Asiatic continent. The volume of Lake Neusiedl can potentially change over the years, in relation with changing balance between atmospheric precipitation and lake water evapotranspiration. Changing water budget, together with high lake salinity and turbidity, have important implications over the lake ecosystem. This contribution illustrates results of the multi-proxi palaeolimnological reconstruction of ecologial changes occurred in Lake Neusiedl during the last ca. 140 years, i.e. since the end of the last "vanished-lake" stage (1865-1871). Geochemical and biological proxies anticipate the increase in lake productivity of ca. 10 years (1950s) respect to what reported in the literature. Diatom species composition indicate a biological lake recovery in the late 1980s, and suggest a second increment in lake productivity since the late 1990s, possibly in relation with the progressive increase in the nitrogen input from agriculture. Abundance of diatoms typical of brackish waters indicated no significant long-term change in lake salinity, while variations in species toleranting dessiccation confirm the vulnerability of Lake Neusiedl toward climate-driven changes in the lake water balance. This fragility is aggravated by the the semi-arid climate conditions of the catchemnt

Hydrological and solute budgets of Lake Qinghai, the largest lake on the Tibetan Plateau

Energy Technology Data Exchange (ETDEWEB)

Jin, Zhangdong [Chinese Academy of Sciences (CAS), Beijing (China); National Cheng Kung Univ., Tainan City (Taiwan); You, Chen-Feng [National Cheng Kung Univ., Tainan City (Taiwan); Wang, Yi [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Shi, Yuewei [Bureau of Hydrology and Water Resources of Qinghai Province, Xining (China)

2009-12-04

Water level and chemistry of Lake Qinghai are sensitive to climate changes and are important for paleoclimatic implications. An accurate understanding of hydrological and chemical budgets is crucial for quantifying geochemical proxies and carbon cycle. Published results of water budget are firstly reviewed in this paper. Chemical budget and residence time of major dissolved constituents in the lake are estimated using reliable water budget and newly obtained data for seasonal water chemistry. The results indicate that carbonate weathering is the most important riverine process, resulting in dominance of Ca ²⁺ and DIC for river waters and groundwater. Groundwater contribution to major dissolved constituents is relatively small (4.2 ± 0.5%). Wet atmospheric deposition contributes annually 7.4–44.0% soluble flux to the lake, resulting from eolian dust throughout the seasons. Estimates of chemical budget further suggest that (1) the Buha-type water dominates the chemical components of the lake water, (2) Na⁺, Cl^-, Mg ²⁺ , and K⁺ in lake water are enriched owing to their conservative behaviors, and (3) precipitation of authigenic carbonates (low-Mg calcite, aragonite, and dolomite) transits quickly dissolved Ca ²⁺ into the bottom sediments of the lake, resulting in very low Ca ²⁺ in the lake water. Therefore, authigenic carbonates in the sediments hold potential information on the relative contribution of different solute inputs to the lake and the lake chemistry in the past.

On the future role of Gulf oil in meeting world energy demand

International Nuclear Information System (INIS)

Nagy Eltony, M.

1996-01-01

The validity of the view of a growing dependence of the world on oil from the Persian Gulf, and the resulting implications for the economies of the Gulf countries were examined. The prevailing view in the countries of the Persian Gulf is that the demand for oil will continue to rise, resulting in the inevitable increase in prices which will in turn alleviate the budget deficit problems currently encountered by most of the countries of the Gulf Cooperation Council (GCC) states. The author argues that the implication of this view is that GCC countries are failing to address the fundamental structural problems within their economies, and raise questions that tend to undermine this hypothesis of continuing dependence on Gulf oil by the rest of the world. Some of these factors are growing reliance on electricity and natural gas, environmental concerns, development of alternative fuels, political instability in the Gulf states and the potential interruption in supply, all of which tend to accelerate the trend towards reduced demand for Gulf oil. The following have been recommended as ways of avoiding the ultimate risk of huge unwanted oil reserves: diversification of the economies of GCC countries; reduced spending and increased investment in developing further capacity from non-GCC sources through cooperation and joint ventures between developing countries and international companies; a more active role in worldwide decisions relating to environmental concerns; and finally, a systematic monitoring and evaluation of the likely impacts of new developments in all areas of alternative energy. 17 refs

Effects of acidity on primary productivity in lakes: phytoplankton. [Lakes Panther, Sagamore, and Woods

Energy Technology Data Exchange (ETDEWEB)

Hendrey, G R

1979-01-01

Relationships between phytoplankton communities and lake acidity are being studied at Woods Lake (pH ca. 4.9), Sagamore Lake (pH ca. 5.5), and Panther Lake (pH ca. 7.0). Numbers of phytoplankton species observed as of July 31, 1979 are Woods 27, Sagamore 38, and Panther 64, conforming to other observations that species numbers decrease with increasing acidity. Patterns of increasing biomass and productivity found in Woods Lake may be atypical of similar oligotrophic lakes in that they develop rather slowly instead of occuring very close to ice-out. Contributions of netplankton (net > 48 ..mu..m), nannoplankton (48 > nanno > 20 ..mu..m) and ultraplankton (20 > ultra >0.45 ..mu..m) to productivity per m/sup -2/ show that the smaller plankton are relatively more important in the more acid lakes. This pattern could be determined by nutrient availability (lake acidification leading to decreased availability of phosphorus). The amount of /sup 14/C-labelled dissolved photosynthate (/sup 14/C-DOM), as a percent of total productivity, is ordered Woods > Sagamore > Panther. This is consistent with a hypothesis that microbial heterotrophic activity is reduced with increasing acidity, but the smaller phytoplankton may be more leaky at low pH. (ERB)

Groundwater-derived nutrient inputs to the Upper Gulf of Thailand

Science.gov (United States)

Burnett, William C.; Wattayakorn, Gullaya; Taniguchi, Makoto; Dulaiova, Henrieta; Sojisuporn, Pramot; Rungsupa, Sompop; Ishitobi, Tomotoshi

2007-01-01

We report here the first direct measurements of nutrient fluxes via groundwater discharge into the Upper Gulf of Thailand. Nutrient and standard oceanographic surveys were conducted during the wet and dry seasons along the Chao Phraya River, Estuary and out into the Upper Gulf of Thailand. Additional measurements in selected near-shore regions of the Gulf included manual and automatic seepage meter deployments, as well as nutrient evaluations of seepage and coastal waters. The river transects characterized the distribution of biogeochemical parameters in this highly contaminated urban environment. Seepage flux measurements together with nutrient analyses of seepage fluids were used to estimate nutrient fluxes via groundwater pathways for comparison to riverine fluxes. Our findings show that disseminated seepage of nutrient-rich mostly saline groundwater into the Upper Gulf of Thailand is significant. Estimated fluxes of dissolved inorganic nitrogen (DIN) supplied via groundwater discharge were 40-50% of that delivered by the Chao Phraya River, inorganic phosphate was 60-70%, and silica was 15-40%. Dissolved organic nitrogen (DON) and phosphorus (DOP) groundwater fluxes were also high at 30-40% and 30-130% of the river inputs, respectively. These observations are especially impressive since the comparison is being made to the river that is the largest source of fresh water into the Gulf of Thailand and flows directly through the megacity of Bangkok with high nutrient loadings from industrial and domestic sources.

Sediment pollution by heavy metals in the Strymonikos and Ierissos Gulfs, North Aegean Sea, Greece.

Science.gov (United States)

Stamatis, Nikolaos; Ioannidouw, Despina; Christoforidis, Achilleas; Koutrakis, Emmanouil

2002-11-01

Surface sediment samples from Strymonikos and Ierissos Gulfs were analyzed for Cu, Pb, Zn, Cr and Ni. The results showed that the sediment of Ierissos Gulf is more polluted with Cu, Pb, and Zn as compared to that of Strymonikos Gulf. The benthal area located off the load-out facility of the mining operations in the town of Stratoni, in Ierissos Gulf is established as the most polluted region. The distribution of Cr and Ni in both gulfs indicates the natural origin of these metals with the weathering of Strymon River and of other smaller rivers rocks being responsible for their enrichment.

Ecology of playa lakes

Science.gov (United States)

Haukos, David A.; Smith, Loren M.

1992-01-01

Between 25,000 and 30,000 playa lakes are in the playa lakes region of the southern high plains (Fig. 1). Most playas are in west Texas (about 20,000), and fewer, in New Mexico, Oklahoma, Kansas, and Colorado. The playa lakes region is one of the most intensively cultivated areas of North America. Dominant crops range from cotton in southern areas to cereal grains in the north. Therefore, most of the native short-grass prairie is gone, replaced by crops and, recently, grasses of the Conservation Reserve Program. Playas are the predominant wetlands and major wildlife habitat of the region.More than 115 bird species, including 20 species of waterfowl, and 10 mammal species have been documented in playas. Waterfowl nest in the area, producing up to 250,000 ducklings in wetter years. Dominant breeding and nesting species are mallards and blue-winged teals. During the very protracted breeding season, birds hatch from April through August. Several million shorebirds and waterfowl migrate through the area each spring and fall. More than 400,000 sandhill cranes migrate through and winter in the region, concentrating primarily on the larger saline lakes in the southern portion of the playa lakes region.The primary importance of the playa lakes region to waterfowl is as a wintering area. Wintering waterfowl populations in the playa lakes region range from 1 to 3 million birds, depending on fall precipitation patterns that determine the number of flooded playas. The most common wintering ducks are mallards, northern pintails, green-winged teals, and American wigeons. About 500,000 Canada geese and 100,000 lesser snow geese winter in the playa lakes region, and numbers of geese have increased annually since the early 1980’s. This chapter describes the physiography and ecology of playa lakes and their attributes that benefit waterfowl.

Biomarkers of Aryl-hydrocarbon Receptor Activity in Gulf Killifish (Fundulus grandis) From Northern Gulf of Mexico Marshes Following the Deepwater Horizon Oil Spill.

Science.gov (United States)

Dubansky, Benjamin; Rice, Charles D; Barrois, Lester F; Galvez, Fernando

2017-07-01

Following the Deepwater Horizon oil spill, shorelines throughout the Barataria Basin of the northern Gulf of Mexico in Louisiana were heavily oiled for months with Macondo-252 oil, potentially impacting estuarine species. The Gulf killifish (Fundulus grandis) has been identified as a sentinel species for the study of site-specific effects of crude oil contamination on biological function. In November and December 2010, 4-5 months after the Macondo well was plugged and new oil was no longer spilling into the Gulf waters, Gulf killifish were collected across the Barataria Basin from 14 sites with varying degrees of oiling. Fish collected from oiled sites exhibited biological indications of exposure to oil, including increase in cytochrome P4501A (CYP1A) mRNA transcript and protein abundances in liver tissues. Immunohistochemistry revealed increases in gill, head kidney, and intestinal CYP1A protein at heavily oiled sites. Intestinal CYP1A protein was a sensitive indicator of exposure, indicating that intestinal tissue plays a key role in biotransformation of AHR ligands and that ingestion is a probable route of exposure, warranting additional consideration in future studies.

78 FR 6404 - Agency Information Collection (Survey of Chronic Gastrointestinal Illness in Persian Gulf...

Science.gov (United States)

2013-01-30

... of Chronic Gastrointestinal Illness in Persian Gulf Veterans) Activities Under OMB Review AGENCY.... Survey of Chronic Gastrointestinal Illness in Persian Gulf Veterans, VA Form 10-21092a. b. VA Research...: Approximately 25 percent military troops who were deployed in the first Persian Gulf War returned with...

76 FR 31018 - Research Advisory Committee on Gulf War Veterans' Illnesses; Notice of Meeting

Science.gov (United States)

2011-05-27

... DEPARTMENT OF VETERANS AFFAIRS Research Advisory Committee on Gulf War Veterans' Illnesses; Notice... Advisory Committee Act) that the Research Advisory Committee on Gulf War Veterans' Illnesses will meet on... consequences of military service in the Southwest Asia theater of operations during the Gulf War. The Committee...

77 FR 2353 - Research Advisory Committee on Gulf War Veterans' Illnesses; Notice of Meeting

Science.gov (United States)

2012-01-17

... DEPARTMENT OF VETERANS AFFAIRS Research Advisory Committee on Gulf War Veterans' Illnesses; Notice... Advisory Committee Act) that the Research Advisory Committee on Gulf War Veterans' Illnesses will meet on... consequences of military service in the Southwest Asia theater of operations during the Gulf War. The Committee...

78 FR 77205 - Research Advisory Committee on Gulf War Veterans' Illnesses; Notice of Meeting

Science.gov (United States)

2013-12-20

... DEPARTMENT OF VETERANS AFFAIRS Research Advisory Committee on Gulf War Veterans' Illnesses; Notice... Advisory Committee Act) that the Research Advisory Committee on Gulf War Veterans' Illnesses will meet on... service in the Southwest Asia theater of operations during the Gulf War. The Committee will review VA...

The problems of the Arabian-Persian gulf

International Nuclear Information System (INIS)

Labrousse, H.

2004-01-01

The origin of the problems of the Arabian-Persian gulf is the delimitation of the maritime borders between the different bordering states and the exploitation rights of the offshore fields. Despite some bilateral agreements, the non-ratification by two bordering states of the United Nations convention on sea rights, deprives some negotiations of any legal framework. The Hormuz strait, the only opening of the gulf towards the Indian ocean, is tightly controlled by maritime powers which will never accept any interference with the maritime circulation in this pathway of considerable importance for petroleum transportation and for the world economy. (J.S.)

A Call for More Research from the Arabian Gulf.

Science.gov (United States)

AlMarri, Fatemah; Al Sabah, Salman; Al Haddad, Eliana; Vaz, Jonathan D

2017-08-01

Obesity has become an epidemic in the Arabian Gulf, with the prevalence of obesity according to the latest report from the World Health Organization (WHO) showing the gulf region to be countries with the highest incidence of obesity in the 30% plus group. This study aims to examine publications on bariatric surgery and compare them with the other countries with a high incidence of obesity in the world. A literature review on bariatric surgery published from the earliest detected year of publication up until March 2016 using SCOPUS, PubMed, Ovid, and Google Scholar was conducted. Individual papers were assessed for types of surgery, preoperative measures, names of journals, authors, and outcomes. The data was analyzed using Endnote library and SPSS. Key words used in the search included "Bariatric Surgery," "Arabian Gulf," "Kuwait," "Qatar," "Saudi Arabia," "United Arab Emirates," "Oman," "USA," "Australia," "weight loss surgery," "sleeve gastrectomy," "gastric bypass," "gastric band," "mini-gastric bypass," "biliropancreatic diversion," "duodenal switch," and "intragastric balloon." Original papers, systematic reviews and case reports were included. From our review, the gastric sleeve proved to be the most popular published on procedure in the Arabian Gulf, whereas the USA had the highest percentage of gastric bypass surgeries and Australia had equivalent numbers when it came to gastric bypass and band. The numbers of studies from Saudi Arabia, Kuwait, UAE, Bahrain, Qatar, and Oman were 70, 44, 20, 7, 6, and 0, respectively. The mean impact factor of the published articles was 2.53 +/- 1.76 SD. Most of the publications were published in Obesity Surgery (29%), Surgery for Obesity and Related Diseases (5%), and Surgical Endoscopy (5%). The Arabian Gulf has both the highest percentage of bariatric procedures performed as well as the highest prevalence of obesity. However, they have the lowest number of publications and research when compared to their western

76 FR 21099 - Determinations Concerning Illnesses Discussed In National Academy of Sciences Reports on Gulf War...

Science.gov (United States)

2011-04-14

... of Sciences Reports on Gulf War and Health, Volumes 4 and 8 AGENCY: Department of Veterans Affairs... that the Secretary of Veterans Affairs, under the authority granted by the Persian Gulf War Veterans...), respectively titled Gulf War and Health, Volume 4: Health Effects of Serving in the Gulf War (Volume 4) and...

Excess unsupported sup(210)Pb in lake sediment from Rocky Mountain lakes

International Nuclear Information System (INIS)

Norton, S.A.; Hess, C.T.; Blake, G.M.; Morrison, M.L.; Baron, J.

1985-01-01

Sediment cores from four high-altitude (approximately 3200 m) lakes in Rocky Mountain National Park, Colorado, were dated by sup(210)Pb chronology. Background (supported) sup(210)Pb activities for the four cores range from 0.26 to 0.93 Beq/g dry weight, high for typical oligotrophic lakes. Integrated unsupported sup(210)Pb ranges from 0.81 (a typical value for most lakes) to 11.0 Beq/cmsup(2). The sup(210)Pb activity in the surface sediments ranges from 1.48 to 22.2 Beq/g dry weight. Sedimentation from Lake Louise, the most unusual of the four, has 22.2 Beq/g dry weight at the sediment surface, an integrated unsupported sup(210)Pb=11.0 Beq/cmsup(2), and supported sup(210)Pb=0.74 Beq/g dry weight. sup(226)Ra content of the sediment is insufficient to explain either the high unsupported sup(210)Pb or the sup(222)Rn content of the water column of Lake Louise, which averaged 96.2 Beq/L. We concluded that sup(222)Rn-rich groundwater entering the lake is the source of the high sup(222)Rn in the water column. This, in turn, is capable of supporting the unusually high sup(210)Pb flux to the sediment surface. Groundwater with high sup(222)Rn may control the sup(210)Pb budget of lakes where sediment cores have integrated unsupported sup(210)Pb greater than 2 Beq/cmsup(2)

The Arabian Gulf and Security Policy: The Past as Present, the Present as Future

Science.gov (United States)

2009-04-01

permeates the Green Zone. Recent cooperation between the Maliki government and Sunni groups represents the tactical “divide-and-conquer” approach to... Kegan Paul, 2005), 76-77. 42. Zahlan, Modern Gulf States, 65. 43. Peck, Gulf Arab States, 38. 44. Zahlan, Modern Gulf States, 67. 70 JSOU Report

Decline of the world's saline lakes

Science.gov (United States)

Wurtsbaugh, Wayne A.; Miller, Craig; Null, Sarah E.; Derose, R. Justin; Wilcock, Peter; Hahnenberger, Maura; Howe, Frank; Moore, Johnnie

2017-11-01

Many of the world's saline lakes are shrinking at alarming rates, reducing waterbird habitat and economic benefits while threatening human health. Saline lakes are long-term basin-wide integrators of climatic conditions that shrink and grow with natural climatic variation. In contrast, water withdrawals for human use exert a sustained reduction in lake inflows and levels. Quantifying the relative contributions of natural variability and human impacts to lake inflows is needed to preserve these lakes. With a credible water balance, causes of lake decline from water diversions or climate variability can be identified and the inflow needed to maintain lake health can be defined. Without a water balance, natural variability can be an excuse for inaction. Here we describe the decline of several of the world's large saline lakes and use a water balance for Great Salt Lake (USA) to demonstrate that consumptive water use rather than long-term climate change has greatly reduced its size. The inflow needed to maintain bird habitat, support lake-related industries and prevent dust storms that threaten human health and agriculture can be identified and provides the information to evaluate the difficult tradeoffs between direct benefits of consumptive water use and ecosystem services provided by saline lakes.

Conifer density within lake catchments predicts fish mercury concentrations in remote subalpine lakes

Science.gov (United States)

Eagles-Smith, Collin A.; Herring, Garth; Johnson, Branden L.; Graw, Rick

2016-01-01

Remote high-elevation lakes represent unique environments for evaluating the bioaccumulation of atmospherically deposited mercury through freshwater food webs, as well as for evaluating the relative importance of mercury loading versus landscape influences on mercury bioaccumulation. The increase in mercury deposition to these systems over the past century, coupled with their limited exposure to direct anthropogenic disturbance make them useful indicators for estimating how changes in mercury emissions may propagate to changes in Hg bioaccumulation and ecological risk. We evaluated mercury concentrations in resident fish from 28 high-elevation, sub-alpine lakes in the Pacific Northwest region of the United States. Fish total mercury (THg) concentrations ranged from 4 to 438 ng/g wet weight, with a geometric mean concentration (±standard error) of 43 ± 2 ng/g ww. Fish THg concentrations were negatively correlated with relative condition factor, indicating that faster growing fish that are in better condition have lower THg concentrations. Across the 28 study lakes, mean THg concentrations of resident salmonid fishes varied as much as 18-fold among lakes. We used a hierarchal statistical approach to evaluate the relative importance of physiological, limnological, and catchment drivers of fish Hg concentrations. Our top statistical model explained 87% of the variability in fish THg concentrations among lakes with four key landscape and limnological variables: catchment conifer density (basal area of conifers within a lake's catchment), lake surface area, aqueous dissolved sulfate, and dissolved organic carbon. Conifer density within a lake's catchment was the most important variable explaining fish THg concentrations across lakes, with THg concentrations differing by more than 400 percent across the forest density spectrum. These results illustrate the importance of landscape characteristics in controlling mercury bioaccumulation in fish.

Stable isotope and hydrogeochemical studies of Beaver Lake and Lake Radok, MacRobertson Land, East Antarctica

International Nuclear Information System (INIS)

Wand, U.; Hermichen, W.D.; Hoefling, R.; Muehle, K.

1987-01-01

Beaver Lake and Lake Radok, the largest known epishelf and the deepest freshwater lake on the Antarctic continent, respectively, were isotopically (δ 2 H, δ 18 O) and hydrogeochemically studied. Lake Radok is an isothermal and non-stratified, i.e. homogeneous water body, while Beaver Lake is stratified with respect to temperature, salinity and isotopic composition. The results for the latter attest to freshwater (derived from snow and glacier melt) overlying seawater. (author)

Environmental status of the Lake Michigan region. Volume 3. Chemistry of Lake Michigan

Energy Technology Data Exchange (ETDEWEB)

Torrey, M S

1976-05-01

The report is a synoptic review of data collected over the past twenty years on the chemistry of Lake Michigan. Changes in water quality and sediment chemistry, attributable to cultural and natural influences, are considered in relation to interacting processes and factors controlling the distribution and concentration of chemical substances within the Lake. Temperature, light, and mixing processes are among the important natural influences that affect nutrient cycling, dispersal of pollutants, and fate of materials entering the Lake. Characterization of inshore-offshore and longitudinal differences in chemical concentrations and sediment chemistry for the main body of the Lake is supplemented by discussion of specific areas such as Green Bay and Grand Traverse Bay. Residues, specific conductance, dissolved oxygen, major and trace nutrients, and contaminants are described in the following context: biological essentiality and/or toxicity, sources to the Lake, concentrations in the water column and sediments, chemical forms, seasonal variations and variation with depth. A summary of existing water quality standards, statutes, and criteria applicable to Lake Michigan is appended.

Assessment of the Great Lakes Marine Renewable Energy Resources: Characterizing Lake Erie Surge, Seiche and Waves

Science.gov (United States)

Farhadzadeh, A.; Hashemi, M. R.

2016-02-01

Lake Erie, the fourth largest in surface area, smallest in volume and shallowest among the Great Lakes is approximately 400 km long and 90 km wide. Short term lake level variations are due to storm surge generated by high winds and moving pressure systems over the lake mainly in the southwest-northeast direction, along the lakes longitudinal axis. The historical wave data from three active offshore buoys shows that significant wave height can exceed 5 m in the eastern and central basins. The long-term lake level data show that storm surge can reach up to 3 m in eastern Lake Erie. Owing its shallow depth, Lake Erie frequently experiences seiching motions, the low frequency oscillations that are initiated by storm surge. The seiches whose first mode of oscillations has a period of nearly 14.2 hours can last from several hours to days. In this study, the Lake Erie potential for power generation, primarily using storm surge and seiche and also waves are assessed. Given the cyclic lake level variations due to storm-induced seiching, a concept similar to that of tidal range development is utilized to assess the potential of storm surge and seiche energy harvesting mechanisms for power generation. In addition, wave energy resources of the Lake is characterized -. To achieve these objectives, the following steps are taken : (1) Frequency of occurrence for extreme storm surge and wave events is determined using extreme value analysis such as Peak-Over-Threshold method for the long-term water level and wave data; (2) Spatial and temporal variations of wave height, storm surge and seiche are characterized. The characterization is carried out using the wave and storm surge outputs from numerical simulation of a number of historical extreme events. The coupled ADCIRC and SWAN model is utilized for the modeling; (3) Assessment of the potentials for marine renewable power generation in Lake Erie is made. The approach can be extended to the other lakes in the Great Lakes region.

Combining lake and watershed characteristics with Landsat TM data for remote estimation of regional lake clarity

Science.gov (United States)

McCullough, Ian M.; Loftin, Cyndy; Sader, Steven A.

2012-01-01

Water clarity is a reliable indicator of lake productivity and an ideal metric of regional water quality. Clarity is an indicator of other water quality variables including chlorophyll-a, total phosphorus and trophic status; however, unlike these metrics, clarity can be accurately and efficiently estimated remotely on a regional scale. Remote sensing is useful in regions containing a large number of lakes that are cost prohibitive to monitor regularly using traditional field methods. Field-assessed lakes generally are easily accessible and may represent a spatially irregular, non-random sample of a region. We developed a remote monitoring program for Maine lakes >8 ha (1511 lakes) to supplement existing field monitoring programs. We combined Landsat 5 Thematic Mapper (TM) and Landsat 7 Enhanced Thematic Mapper Plus (ETM+) brightness values for TM bands 1 (blue) and 3 (red) to estimate water clarity (secchi disk depth) during 1990–2010. Although similar procedures have been applied to Minnesota and Wisconsin lakes, neither state incorporates physical lake variables or watershed characteristics that potentially affect clarity into their models. Average lake depth consistently improved model fitness, and the proportion of wetland area in lake watersheds also explained variability in clarity in some cases. Nine regression models predicted water clarity (R2 = 0.69–0.90) during 1990–2010, with separate models for eastern (TM path 11; four models) and western Maine (TM path 12; five models that captured differences in topography and landscape disturbance. Average absolute difference between model-estimated and observed secchi depth ranged 0.65–1.03 m. Eutrophic and mesotrophic lakes consistently were estimated more accurately than oligotrophic lakes. Our results show that TM bands 1 and 3 can be used to estimate regional lake water clarity outside the Great Lakes Region and that the accuracy of estimates is improved with additional model variables that reflect

CMS: Simulated Physical-Biogeochemical Data, SABGOM Model, Gulf of Mexico, 2005-2010

Data.gov (United States)

National Aeronautics and Space Administration — This dataset contains monthly mean ocean surface physical and biogeochemical data for the Gulf of Mexico simulated by the South Atlantic Bight and Gulf of Mexico...

Treating floodplain lakes of large rivers as study units for variables that vary within lakes; an evaluation using chlorophyll a and inorganic suspended solids data from floodplain lakes of the Upper Mississippi River

Science.gov (United States)

Gray, B.R.; Rogala, J.R.; Houser, J.N.

2013-01-01

Contiguous floodplain lakes ('lakes') have historically been used as study units for comparative studies of limnological variables that vary within lakes. The hierarchical nature of these studies implies that study variables may be correlated within lakes and that covariate associations may differ not only among lakes but also by spatial scale. We evaluated the utility of treating lakes as study units for limnological variables that vary within lakes based on the criteria of important levels of among-lake variation in study variables and the observation of covariate associations that vary among lakes. These concerns were selected, respectively, to ensure that lake signatures were distinguishable from within-lake variation and that lake-scale effects on covariate associations might provide inferences not available by ignoring those effects. Study data represented chlorophyll a (CHL) and inorganic suspended solids (ISS) data from lakes within three reaches of the Upper Mississippi River. Sampling occurred in summer from 1993 through 2005 (except 2003); numbers of lakes per reach varied from 7 to 19, and median lake area varied from 53 to 101 ha. CHL and ISS levels were modelled linearly, with lake, year and lake x year effects treated as random. For all reaches, the proportions of variation in CHL and ISS attributable to differences among lakes (including lake and lake x year effects) were substantial (range: 18%-73%). Finally, among-lake variation in CHL and ISS was strongly associated with covariates and covariate effects that varied by lakes or lake-years (including with vegetation levels and, for CHL, log(ISS)). These findings demonstrate the utility of treating floodplain lakes as study units for the study of limnological variables and the importance of addressing hierarchy within study designs when making inferences from data collected within floodplain lakes.

Global Lakes Sentinel Services: Evaluation of Chl-a Trends in Deep Clear Lakes

Science.gov (United States)

Cazzaniga, Ilaria; Giardino, Claudia; Bresciani, Mariano; Poser, Kathrin; Peters, Steef; Hommersom, Annelies; Schenk, Karin; Heege, Thomas; Philipson, Petra; Ruescas, Ana; Bottcher, Martin; Stelzer, Kerstin

2016-08-01

The aim of this study is the analysis of trend in the trophic level evolution in clear deep lakes which, being characterised by good quality state, are important socio- economic resources for their regions. The selected lakes are situated in Europe (Garda, Maggiore, Constance and Vättern), North America (Michigan) and Africa (Malawi and Tanganyika) and cover a range of eco- regions (continental, perialpine, boreal, rift valley) distributed globally.To evaluate trophic level tendency we mainly focused on chlorophyll-a concentrations (chl-a) which is a direct proxy of trophic status. The chl-a concentrations were obtained from 5216 cloud-free MERIS imagery from 2002 to 2012.The 'GLaSS RoIStats tool' available within the GLaSS project was used to extract chl-a in a number of region of interests (ROI) located in pelagic waters as well as some few other stations depending on lakes morphology. For producing the time-series trend, these extracted data were analysed with the Seasonal Kendall test.The results overall show almost stable conditions with a slight increase in concentration for lakes Maggiore, Constance, and the Green Bay of Lake Michigan; a slight decrease for lakes Garda and Tanganyika and absolutely stable conditions for lakes Vättern and Malawi.The results presented in this work show the great capability of MERIS to perform trend tests analysis on trophic status with focus on chl-a concentration. Being chl-a also a key parameter in water quality monitoring plans, this study also supports the managing practices implemented worldwide for using the water of the lakes.

Benthic-planktonic coupling, regime shifts, and whole-lake primary production in shallow lakes.

Science.gov (United States)

Genkai-Kato, Motomi; Vadeboncoeur, Yvonne; Liboriussen, Lone; Jeppesen, Erik

2012-03-01

Alternative stable states in shallow lakes are typically characterized by submerged macrophyte (clear-water state) or phytoplankton (turbid state) dominance. However, a clear-water state may occur in eutrophic lakes even when macrophytes are absent. To test whether sediment algae could cause a regime shift in the absence of macrophytes, we developed a model of benthic (periphyton) and planktonic (phytoplankton) primary production using parameters derived from a shallow macrophyte-free lake that shifted from a turbid to a clear-water state following fish removal (biomanipulation). The model includes a negative feedback effect of periphyton on phosphorus (P) release from sediments. This in turn induces a positive feedback between phytoplankton production and P release. Scenarios incorporating a gradient of external P loading rates revealed that (1) periphyton and phytoplankton both contributed substantially to whole-lake production over a broad range of external P loading in a clear-water state; (2) during the clear-water state, the loss of benthic production was gradually replaced by phytoplankton production, leaving whole-lake production largely unchanged; (3) the responses of lakes to biomanipulation and increased external P loading were both dependent on lake morphometry; and (4) the capacity of periphyton to buffer the effects of increased external P loading and maintain a clear-water state was highly sensitive to relationships between light availability at the sediment surface and the of P release. Our model suggests a mechanism for the persistence of alternative states in shallow macrophyte-free lakes and demonstrates that regime shifts may trigger profound changes in ecosystem structure and function.

Rickettsia parkeri in Gulf Coast Ticks, Southeastern Virginia, USA

Science.gov (United States)

2011-05-01

Rickettsia parkeri in Gulf Coast Ticks, Southeastern Virginia, USA Chelsea L. Wright, Robyn M. Nadolny, Ju Jiang, Allen L. Richards, Daniel E...Virginia. We found that 43.1% of the adult Gulf Coast ticks collected in the summer of 2010 carried Rickettsia parkeri, suggesting that persons living in...or visiting southeastern Virginia are at risk for infection with this pathogen. Rickettsia parkeri is an obligate intracellular bacterium belonging

Changes in depth occupied by Great Lakes lake whitefish populations and the influence of survey design

Science.gov (United States)

Rennie, Michael D.; Weidel, Brian C.; Claramunt, Randall M.; Dunlob, Erin S.

2015-01-01

Understanding fish habitat use is important in determining conditions that ultimately affect fish energetics, growth and reproduction. Great Lakes lake whitefish (Coregonus clupeaformis) have demonstrated dramatic changes in growth and life history traits since the appearance of dreissenid mussels in the Great Lakes, but the role of habitat occupancy in driving these changes is poorly understood. To better understand temporal changes in lake whitefish depth of capture (Dw), we compiled a database of fishery-independent surveys representing multiple populations across all five Laurentian Great Lakes. By demonstrating the importance of survey design in estimating Dw, we describe a novel method for detecting survey-based bias in Dw and removing potentially biased data. Using unbiased Dw estimates, we show clear differences in the pattern and timing of changes in lake whitefish Dw between our reference sites (Lake Superior) and those that have experienced significant benthic food web changes (lakes Michigan, Huron, Erie and Ontario). Lake whitefish Dw in Lake Superior tended to gradually shift to shallower waters, but changed rapidly in other locations coincident with dreissenid establishment and declines in Diporeia densities. Almost all lake whitefish populations that were exposed to dreissenids demonstrated deeper Dw following benthic food web change, though a subset of these populations subsequently shifted to more shallow depths. In some cases in lakes Huron and Ontario, shifts towards more shallow Dw are occurring well after documented Diporeia collapse, suggesting the role of other drivers such as habitat availability or reliance on alternative prey sources.

Time required for gulf restoration uncertain

International Nuclear Information System (INIS)

Anon.

1992-01-01

Hurricane Andrew's long term effect on Gulf of Mexico oil and gas operations likely won't be known until next year. This paper reports that while damage assessments have moved beyond the emergency stage, many offshore service companies say reliable estimates of the extent of damage or cost of repairs still are unavailable. The time needed to complete restorations won't be known conclusively until more organized surveys are complete. Even then, many contractors say, gulf operators must decide how to handle damage at each location-whether to repair damaged structures or replace them by applying technology not available when many of the fields were developed. Some damaged installations will not be replaced or restored, and the production will be lost

[Immigration in the countries of the Gulf: some specific aspects].

Science.gov (United States)

Labib, A

1987-06-01

"This essay analyses some aspects of the in-migration flows to the Gulf countries, coming from other Arab countries as well as developing nations. Since the 80's, the Gulf countries have endorsed a restrictive policy concerning manpower import, even though they still need foreign workers. The Gulf countries pursue this policy as they fear that the presence of millions of foreign labourers will create social tension. The situation of the foreign labour force is uncertain and is bound to the role of the middleman, the local kafil, and that of the recruiting agencies. Rotation of foreign workers is very high. It has reached the 10 million mark in ten years." (SUMMARY IN ENG) excerpt

Historical changes to Lake Washington and route of the Lake Washington Ship Canal, King County, Washington

Science.gov (United States)

Chrzastowski, Michael J.

1983-01-01

Lake Washington, in the midst of the greater Seattle metropolitan area of the Puget Sound region (fig. 1), is an exceptional commercial, recreational, and esthetic resource for the region . In the past 130 years, Lake Washington has been changed from a " wild " lake in a wilderness setting to a regulated lake surrounded by a growing metropolis--a transformation that provides an unusual opportunity to study changes to a lake's shoreline and hydrologic characteristics -resulting from urbanization.

Climatic changes inferred fron analyses of lake-sediment cores, Walker Lake, Nevada

International Nuclear Information System (INIS)

Yang, In Che.

1989-01-01

Organic and inorganic fractions of sediment collected from the bottom of Walker Lake, Nevada, have been dated by carbon-14 techniques. Sedimentation rates and the organic-carbon content of the sediment were correlated with climatic change. The cold climate between 25,000 and 21,000 years ago caused little runoff, snow accumulation on the mountains, and rapid substantial glacial advances; this period of cold climate resulted in a slow sedimentation rate (0.20 millimeter per year) and in a small organic-carbon content in the sediment. Also, organic-carbon accumulation rates in the lake during this period were slow. The most recent period of slow sedimentation rate and small organic-carbon content occurred between 10,000 and 5500 years ago, indicative of low lake stage and dry climatic conditions. This period of dry climate also was evidenced by dry conditions for Lake Lahontan in Nevada and Searles Lake in California, as cited in the literature. Walker Lake filled rapidly with water between 5500 and 4500 years ago. The data published in this report was not produced under an approved Site Investigation Plan (SIP) or Study Plan (SP) and will not be used in the licensing process. 10 refs., 3 figs., 2 tabs

Survey and assessment of post volcanic activities of a young caldera lake, Lake Cuicocha, Ecuador

Directory of Open Access Journals (Sweden)

G. Gunkel

2009-05-01

Full Text Available Cuicocha is a young volcano adjacent to the inactive Pleistocene Cotacachi volcano complex, located in the western cordilleras of the Ecuadorian Andes. A series of eruptions with intensive ash emission and collapse of the caldera occurred around 4500–3000 y BP. A crater 3.2 km in diameter and a maximum depth of 450 m was formed. Further eruptions of the volcano occurred 1300 y BP and formed four smaller domes within the caldera. Over the last few hundred years, a caldera lake has developed, with a maximum depth of 148 m. The lake water is characterized by sodium carbonate with elevated concentrations of manganese, calcium and chloride. Nowadays, an emission of gases, mainly CO₂, and an input of warm spring water occur in Lake Cuicocha. The zone of high activity is in the western basin of the lake at a depth of 78 m, and continuous gas emissions with sediment resuspension were observed using sonar. In the hypolimnion of the lake, CO₂ accumulation occurs up to 0.2% saturation, but the risk of a limnic eruption can be excluded at present. The lake possesses monomictic stratification behaviour, and during overturn an intensive gas exchange with the atmosphere occurs. Investigations concerning the sedimentation processes of the lake suggest only a thin sediment layer of up to 10–20 cm in the deeper lake basin; in the western bay, in the area of gas emissions, the lake bottom is partly depleted of sediment in the form of holes, and no lake colmation exists. Decreases in the lake water level of about 30 cm y⁻¹ indicate a percolation of water into fractures and fissures of the volcano, triggered by a nearby earthquake in 1987.

A Synoptic Climatology of Heavy Rain Events in the Lake Eyre and Lake Frome Catchments

Directory of Open Access Journals (Sweden)

Michael John Pook

2014-11-01

Full Text Available The rare occasions when Lake Eyre in central, southern Australia fills with water excite great interest and produce major ecological responses. The filling of other smaller lakes such as Lake Frome, have less impact but can contribute important information about the current and past climates of these arid regions. Here, the dominant synoptic systems responsible for heavy rainfall over the catchments of Lake Eyre and Lake Frome since 1950 are identified and compared. Heavy rain events are defined as those where the mean catchment rainfall for 24 hours reaches a prescribed threshold. There were 25 such daily events at Lake Eyre and 28 in the Lake Frome catchment. The combination of a monsoon trough at mean sea level and a geopotential trough in the mid-troposphere was found to be the synoptic system responsible for the majority of the heavy rain events affecting Lake Eyre and one in five of the events at Lake Frome. Complex fronts where subtropical interactions occurred with Southern Ocean fronts also contributed over 20% of the heavy rainfall events in the Frome catchment. Surface troughs without upper air support were found to be associated with 10% or fewer of events in each catchment, indicating that mean sea level pressure analyses alone do not adequately capture the complexity of the heavy rainfall events. At least 80% of the heavy rain events across both catchments occurred when the Southern Oscillation Index (SOI was in its positive phase, and for Lake Frome, the SOI exceeded +10 on 60% of occasions, suggesting that the background atmospheric state in the Pacific Ocean was tilted towards La Niña. Hydrological modeling of the catchments suggests that the 12-month running mean of the soil moisture in a sub-surface layer provides a low frequency filter of the precipitation and matches measured lake levels relatively well.

77 FR 9897 - Gulf of Mexico Fishery Management Council; Public Meetings

Science.gov (United States)

2012-02-21

.... SUMMARY: The Gulf of Mexico Fishery Management Council (Council) will convene its Special Coral Scientific... Mexico Fishery Management Council; Public Meetings AGENCY: National Marine Fisheries Service (NMFS... Management Council, 2203 N. Lois Avenue, Suite 1100, Tampa, FL 33607. Council address: Gulf of Mexico Fishery...

77 FR 4282 - Gulf of Mexico Fishery Management Council; Public Meeting

Science.gov (United States)

2012-01-27

... meeting. SUMMARY: The Gulf of Mexico Fishery Management Council will convene a meeting of the Shrimp Stock... Laboratory, 4700 Avenue U, Galveston, TX 77551-5997. Council address: Gulf of Mexico Fishery Management... Management Council; telephone: (813) 348-1630. SUPPLEMENTARY INFORMATION: The Shrimp Stock Assessment Review...

Seasonal characteristics of water exchange in Beibu Gulf based on a particle tracking model

Science.gov (United States)

Wang, L.; Pan, W.; Yan, X.

2016-12-01

A lagrangian particle tracking model coupled with a three-dimensional Marine Environmental Committee Ocean Model (MEC) is used to study the transport and seasonal characteristics of water exchange in Beibu Gulf. The hydrodynamic model (MEC), which is forced with the daily surface and lateral boundary fluxes, as well as tidal harmonics and monthly climatological river discharges, is applied to simulate the flow field in the gulf during 2014. Using these results, particle tracking method which includes tidal advection and random walk in the horizontal is used to determine the residence times of sub regions within the gulf in response of winter and summer wind forcing. The result shows water exchange processes in the gulf have a similar tendency with seasonal circulation structure. During the sourthwestly prevailing wind in summer, water particles are traped within the gulf that considerably increases the residence time of each sub region. On the contrary, the presence of strong northeastly prevailing wind in winter drives particles to move cyclonicly leading to shorter residence times and rather active water exchanges among sub regions. Similarly, particle tracking is applied to investigate the water transport in Beibu Gulf. As Qiongzhou Strait and the wide opening in the south of the gulf are two significant channels connecting with the open ocean, continuous particle releases are simulated to quantify the influence range and the pathways of these sources water flowing into Beibu Gulf. The results show that water particles originated from Qiongzhou Strait are moving westward due to the year-round strong westward flow transportation. Influencing range in the north of the Beibu Gulf is enlarged by winter northeastly wind, however, it is blocked to the Leizhou Peninsula coastal region by summer westly wind. In the south opening, water particles are transported northward into the gulf along Hainan Island and flushed from Vietnam coastal region to the ocean rapidly by

Expanding models of lake trophic state to predict cyanobacteria in lakes

Science.gov (United States)

Background/Question/Methods: Cyanobacteria are a primary taxonomic group associated with harmful algal blooms in lakes. Understanding the drivers of cyanobacteria presence has important implications for lake management and for the protection of human and ecosystem health. Chlor...

The ralationship between the Tamarix spp. growth and lake level change in the Bosten Lake,northwest China

Science.gov (United States)

Ye, Mao; Hou, JiaWen

2015-04-01

Dendrochronology methods are used to analyze the characteristics of Tamarix spp. growth in Bosten Lake. Based on the long-term annual and monthly data of lake level, this paper models the relationship between ring width of Tamarix spp. and lake level change. The sensitivity index is applied to determine the rational change range of lake level for protecting the Tamarix spp. growth. The results show that :( 1) the annual change of lake level in Bosten Lake has tree evident stages from 1955 to 2012. The monthly change of lake level has two peak values and the seasonal change is not significant; (2) the average value of radical width of Tamarix spp. is 3.39mm. With the increment of Tamarix spp. annual growth , the average radical width has a decreasing trend, which is similar to the annual change trend of lake level in the same years ;( 3) the response of the radical width of Tamarix spp. to annual change of lake level is sensitive significantly. When the lake level is 1045.66m, the Sk value of radical width of Tamarix spp. appears minimum .when the lake level is up to1046.27m, the Sk value is maximum. Thus the sensitivity level of radical width of Tamarix spp. is 1045.66- 1046.27m which could be regarded as the rational lake level change range for protecting the Tamarix spp. growth.

Lake Chad, Chad, Africa

Science.gov (United States)

1992-01-01

Hydrologic and ecologic changes in the Lake Chad Basin are shown in this Oct 1992 photograph. In space photo documentation, Lake Chad was at its greatest area extent (25,000 sq. km.) during Gemini 9 in June 1966 (see S66-38444). Its reduction during the severe droughts from 1968 to 1974 was first noted during Skylab (1973-1974). After the drought began again in 1982, the lake reached its minimum extent (1,450 sq. km.) in Space Shuttle photographs taken in 1984 and 1985. In this STS-52 photograph, Lake Chad has begun to recover. The area of the open water and interdunal impoundments in the southern basin (the Chari River Basin) is estimated to be 1,900 to 2100 sq. km. Note the green vegetation in the valley of the K'Yobe flow has wetted the northern lake basin for the first time in several years. There is evidence of biomass burning south of the K'Yobe Delta and in the vegetated interdunal areas near the dike in the center of the lake. Also note the dark 'Green Line' of the Sahel (the g

Cost-effective reduction of eutrophication in the Gulf of Kalloni (Island of Lesvos, Greece

Directory of Open Access Journals (Sweden)

B. ZANOU

2001-06-01

Full Text Available This study presents a cost-effective analysis by comparing the costs of measures (options to improve the quality of bathing waters in the Gulf of Kalloni (island of Lesvos, Greece in order to reduce the anthropogenic eutrophication in the coastal water of the Kalloni Gulf. The Gulf of Kalloni is a semi-enclosed gulf (115 km2 which receives municipal wastewater, agricultural activity drainage, and at times sewage from olive oil plants processing the local olives harvest. The area of study consists of the coastal waters and the river basin of which water run-off drains into the gulf. Four options are comparable in their environmental effectiveness to reduce eurtophication damages which are: municipal wastewater treatment plant, construction of dams, organic farming plus training and olive oil wastewater treatment plant.

First record of two hard coral species (Faviidae and Siderastreidae from Qeshm Island (Persian Gulf, Iran

Directory of Open Access Journals (Sweden)

MOHAMMAD SHARIF RANJBAR

2010-01-01

Full Text Available Moradi M, Kamrani E, Shokri MR, Ranjbar MS, Hesni MA (2009 First record of two hard coral species (Faviidae and Siderastreidae from Qeshm Island (Persian Gulf, Iran. Nusantara Bioscience 2: 34-37. Two species of hard corals including Cyphastrea chalcidicum (Forskal 1775 (Faviidae and Coscinaraea monile (Forskal 1775 (Siderastreidae were collected from the south of Qeshm Island (Persian Gulf, Iran in the late of 2008. These species were previously reported from southern Persian Gulf, Gulf of Aden, Southeast Africa and Indo-Pacific. The literature review on the distribution of these two species revealed that these species were firstly recorded from the Persian Gulf. These findings further emphasize the high diversity of coral fauna in the Iranian waters of the northern Persian Gulf.

Preliminary observations of environmental damage due to the Gulf War

International Nuclear Information System (INIS)

El-Baz, F.

1992-01-01

Preparing for and conducting the Gulf War resulted in much damage to the environment of the region. The first and most visible effect is related to the damage caused by oil well fires in terms of air pollution as well as the potential damage to the petroleum reservoirs. The second detrimental effect has been caused by the oil spill in the Gulf water. Hundreds of miles of the western coastline of the Gulf are already covered with oil. Petroleum 'mats' have settled on coral reefs and have reduced Gulf water productivity. Foremost among the irreparable damages are changes to the terrain due to the digging of trenches, building walls of soil and otherwise disturbing the desert pavement in and around Kuwait. Disruption of the, usually, one-grain thick layer of pebbles on the desert floor exposes soil to wind action. Changing the contours of the normally flat land increases resistance to the wind and increases the potential of particle transport until the land is peneplained. This condition will increase the frequency and the ferocity of dust storms in the region. It will also result in the formation of new sand dunes; sand drifts already exist along roads in northern Kuwait. It is believed that the detrimental effects on the atmosphere will last for years, on the Gulf water for decades, and on the desert surface for centuries. (author). 12 refs, 1 fig

Preliminary observations of environmental damage due to the Gulf War

Energy Technology Data Exchange (ETDEWEB)

El-Baz, F [Boston Univ., Boston, MA (United States). Center for Remote Sensing

1992-02-01

Preparing for and conducting the Gulf War resulted in much damage to the environment of the region. The first and most visible effect is related to the damage caused by oil well fires in terms of air pollution as well as the potential damage to the petroleum reservoirs. The second detrimental effect has been caused by the oil spill in the Gulf water. Hundreds of miles of the western coastline of the Gulf are already covered with oil. Petroleum 'mats' have settled on coral reefs and have reduced Gulf water productivity. Foremost among the irreparable damages are changes to the terrain due to the digging of trenches, building walls of soil and otherwise disturbing the desert pavement in and around Kuwait. Disruption of the, usually, one-grain thick layer of pebbles on the desert floor exposes soil to wind action. Changing the contours of the normally flat land increases resistance to the wind and increases the potential of particle transport until the land is peneplained. This condition will increase the frequency and the ferocity of dust storms in the region. It will also result in the formation of new sand dunes; sand drifts already exist along roads in northern Kuwait. It is believed that the detrimental effects on the atmosphere will last for years, on the Gulf water for decades, and on the desert surface for centuries. (author). 12 refs, 1 fig.

75 FR 70162 - Presumptive Service Connection for Diseases Associated With Persian Gulf War Service: Functional...

Science.gov (United States)

2010-11-17

... Diseases Associated With Persian Gulf War Service: Functional Gastrointestinal Disorders AGENCY: Department... theater of operations during the Persian Gulf War. DATES: Comments must be received by VA on or before... Service Connection for Diseases Associated With Persian Gulf War Service: Functional Gastrointestinal...

Fatty Acid Composition and Levels of Selected Polyunsaturated Fatty Acids in Four Commercial Important Freshwater Fish Species from Lake Victoria, Tanzania

Directory of Open Access Journals (Sweden)

Agnes Robert

2014-01-01

Full Text Available Fatty acids (FAs particularly ω3 and ω6 polyunsaturated fatty acids (PUFAs play important role in human health. This study aimed to investigate the composition and levels of selected ω3 PUFAs in four commercial fish species, Nile perch (Lates niloticus, Nile tilapia (Oreochromis niloticus, Tilapia zillii, and dagaa (Rastrineobola argentea from Mwanza Gulf in Lake Victoria. The results indicated that 36 types of FAs with different saturation levels were detected. These FAs were dominated by docosahexaenoic (DHA, eicosapentaenoic (EPA, docosapentaenoic (DPA, and eicosatetraenoic acids. O. niloticus had the highest composition of FAs (34 compared to L. niloticus (27, T. zillii (26, and R. argentea (21. The levels of EPA differed significantly among the four commercial fish species (F=6.19,  P=0.001. The highest EPA levels were found in R. argentea followed by L. niloticus and O. niloticus and the lowest in T. zillii. The DPA levels showed no significant difference among the four fish species studied (F=0.652,  P=0.583. The study concluded that all four commercial species collected from Mwanza Gulf are good for human health, but R. argentea is the best for consumption because it contains higher levels of ω3 FAs, mainly EPA.

Why is Coastal Community Resilience Important in the Gulf of Mexico Region?

Science.gov (United States)

The Gulf of Mexico Program supports the regional collaborative approach and efforts of the Coastal Community Resilience Priority Issue Team of the Gulf of Mexico Governors’ Alliance and its broad spectrum of partners and stakeholders.

Implication of coastal refineries to the ecology of the Gulf of Kachchh

Digital Repository Service at National Institute of Oceanography (India)

Zingde, M.D.; Anand, N.M.

bank of the Gulf of Kachchh. An assessment of probable impact of establishment of these refineries to the rich biodiversity of the Gulf and suggestions to minimise these impacts have been made in this paper....

Lake Morphometry for NHD Lakes in Souris Red Rainy Region 9 HUC

Data.gov (United States)

U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

Lake Morphometry for NHD Lakes in Arkansas White Red Region 11 HUC

Data.gov (United States)

U.S. Environmental Protection Agency — Lake morphometry metrics are known to influence productivity in lakes and are important for building various types of ecological and environmental models of lentic...

76 FR 61695 - Gulf of Mexico Regional Ecosystem Restoration Strategy (Preliminary)

Science.gov (United States)

2011-10-05

... ENVIRONMENTAL PROTECTION AGENCY [EPA-HQ-OA-2011-0798; FRL-9475-6] Gulf of Mexico Regional... of Availability. SUMMARY: This notice announces the availability of the Gulf of Mexico Regional... http://www.regulations.gov in the docket identified by Docket ID No. EPA-HQ-OA-2011-0798. President...

77 FR 59901 - Gulf of Mexico Fishery Management Council; Public Meeting

Science.gov (United States)

2012-10-01

.... SUMMARY: The Gulf of Mexico Fishery Management Council (Council) will convene its Law Enforcement Advisory Panel in conjunction with the Gulf States Marine Fisheries Commission's Law Enforcement Committee. DATES... meeting will be held at the Grand Hotel Marriott Resort, One Grand Boulevard, Point Clear, AL 36564...

Influence of permafrost on lake terraces of Lake Heihai (NE Tibetan Plateau)

Science.gov (United States)

Lockot, Gregori; Hartmann, Kai; Wünnemann, Bernd

2013-04-01

The Tibetan Plateau (TP) is one of the key regions for climatic global change. Besides the poles the TP is the third highest storage of frozen water in glaciers. Here global warming is three times higher than in the rest of the world. Additionally the TP provides water for billions of people and influences the moisture availability from the Indian and East Asian monsoon systems. During the Holocene extent and intensity of the monsoonal systems changed. Hence, in the last decades, a lot of work was done to reconstruct timing and frequency of monsoonal moisture, to understand the past and give a better forecast for the future. Comparative workings often show very heterogeneous patterns of timing and frequency of the Holocene precipitation and temperature maximum, emphasizing the local importance of catchment dynamics. In this study we present first results of lake Heihai (36°N, 93°15'E, 4500m a.s.l.), situated at the north-eastern border of the TP. The lake is surrounded by a broad band of near-shore lake sediments, attesting a larger lake extent in the past. These sediments were uplifted by permafrost, reaching nowadays heights ca. +8 meters above present lake level. Due to the uplift one of the main inflows was blocked and the whole hydrology of the catchment changed. To quantify the uplift of permafrost Hot Spot Analysis were accomplished at a DEM of the near-shore area. As a result regions of high permafrost uplift and those which mirror the original height of lake ground were revealed. The most obvious uplift took place in the northern and western part of the lake, where the four uplift centers are located. In contrast the southern and eastern areas show a rather degraded pattern (probably by fluvial erosion, thermokarst, etc.). The ancient lake bottom, without permafrost uplift was estimated to be 4-6 meters above the modern lake level. For a better understanding of permafrost interaction inside the terrace bodies a 5m sediment profile was sampled and

Lake sediments as natural seismographs: Earthquake-related deformations (seismites) in central Canadian lakes

Science.gov (United States)

Doughty, M.; Eyles, N.; Eyles, C. H.; Wallace, K.; Boyce, J. I.

2014-11-01

Central Canada experiences numerous intraplate earthquakes but their recurrence and source areas remain obscure due to shortness of the instrumental and historic records. Unconsolidated fine-grained sediments in lake basins are 'natural seismographs' with the potential to record ancient earthquakes during the last 10,000 years since the retreat of the Laurentide Ice Sheet. Many lake basins are cut into bedrock and are structurally-controlled by the same Precambrian basement structures (shear zones, terrane boundaries and other lineaments) implicated as the source of ongoing mid-plate earthquake activity. A regional seismic sub-bottom profiling of lakes Gull, Muskoka, Joseph, Rousseau, Ontario, Wanapitei, Fairbanks, Vermilion, Nipissing, Georgian Bay, Mazinaw, Simcoe, Timiskaming, Kipawa, Parry Sound and Lake of Bays, encompassing a total of more than 2000 kilometres of high-resolution track line data supplemented by multibeam and sidescan sonar survey records show a consistent sub-bottom stratigraphy of relatively-thick lowermost lateglacial facies composed of interbedded semi-transparent mass flow facies (debrites, slumps) and rhythmically-laminated silty-clays. Mass flows together with cratered ('kettled') lake floors and associated deformations reflect a dynamic ice-contact glaciolacustrine environment. Exceptionally thick mass flow successions in Lake Timiskaming along the floor of the Timiskaming Graben within the seismically-active Western Quebec Seismic Zone (WQSZ), point to a higher frequency of earthquakes and slope failure during deglaciation and rapid glacio-isostatic rebound though faulting continues into the postglacial. Lateglacial faulting, diapiric deformation and slumping of coeval lateglacial sediments is observed in Parry Sound, Lake Muskoka and Lake Joseph, which are all located above prominent Precambrian terrane boundaries. Lateglacial sediments are sharply overlain by relatively-thin rhythmically-laminated and often semi

Whiting in Lake Michigan

Science.gov (United States)

2002-01-01

Satellites provide a view from space of changes on the Earth's surface. This series of images from the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) aboard the Orbview-2 satellite shows the dramatic change in the color of Lake Michigan during the summer. The bright color that appears in late summer is probably caused by calcium carbonate-chalk-in the water. Lake Michigan always has a lot of calcium carbonate in it because the floor of the lake is limestone. During most of the year the calcium carbonate remains dissolved in the cold water, but at the end of summer the lake warms up, lowering the solubility of calcium carbonate. As a result, the calcium carbonate precipitates out of the water, forming clouds of very small solid particles that appear as bright swirls from above. The phenomenon is appropriately called a whiting event. A similar event occured in 1999, but appears to have started later and subsided earlier. It is also possible that a bloom of the algae Microcystis is responsible for the color change, but unlikely because of Lake Michigan's depth and size. Microcystis blooms have occured in other lakes in the region, however. On the shore of the lake it is possible to see the cities of Chicago, Illinois, and Milwaukee, Wisconsin. Both appear as clusters of gray-brown pixels. Image courtesy the SeaWiFS Project, NASA/Goddard Space Flight Center, and ORBIMAGE

Lake-0: A model for the simulation of nuclides transfer in lake scenarios

International Nuclear Information System (INIS)

Garcia-Olivares, A.; Aguero, A.; Pinedo, P.

1994-01-01

This report presents documentation and a user's manual for the program LAKE-0, a mathematical model of nuclides transfer in lake scenarios. Mathematical equations and physical principles used to develop the code are presented in section 2. The program use is presented in section 3 including input data sets and output data. Section 4 presents two example problems, and some results. The complete program listing including comments is presented in Appendix A. Nuclides are assumed to enter the lake via atmospheric deposition and carried by the water runoff and the dragged sediments from the adjacent catchment. The dynamics of the nuclides inside the lake is based in the model proposed by Codell (11) as modified in (5). The removal of concentration from the lake water is due to outflow from the lake and to the transfer of activity to the bottom sediments. The model has been applied to the Esthwaite Water (54 degree 21 minute N, 03 degree 00 minute W at 65 m. asl.) in the frame of the VAMP Aquatic Working Group (8) and to Devoke Water (54 degree 21 minute 5'N, 03 degree, 18 minute W at 230 m. asl.)

LAKE-0: a model for the simulation of nuclides transfer in lake scenarios

International Nuclear Information System (INIS)

Garcia-Olivares, A.; Aguero, A.; Pinedo, P.

1994-01-01

This report presents documentation and a user's manual for the program LAKE-0, a mathematical model of nuclides transfer in lake scenarios. Mathematical equations and physical principles used to develop the code are presented in section 2. The program use is presented in section 3 including input data sets and output data. Section 4 presents two example problems, and some results. The complete program listing including comments is presented in Appendix A. Nuclides are assumed to center the lake via atmospheric deposition and carried by the water runoff and the dragged sediments from the adjacent catchment. The dynamics of the nuclides inside the lake is based in the model proposed by Codell (11) as modified in (5). The removal of concentration from the lake water is due to out flow from the lake and to the transfer of activity to the button sediments. The model has been applied to the Esthwaite Water (54 degree celsius 2 l'N, 03 degree celsius 00'W at 65 m. asi.) in the frame of the VAMP Aquatic Working Group (8) and to Devoke Water (5 21.5'N, 03H8'W at 230 m. asi.). (Author). 13 refs

Infectious Diseases - Diseases Related to Service in Gulf War, Iraq, and Afghanistan

Science.gov (United States)

... qualify for VA health care . Diseases related to Gulf War, Iraq and Afghanistan service VA presumes that the ... Southwest Asia theater of military operations during the Gulf War August 2, 1990 to present and in Afghanistan ...

Development and evaluation of the Lake Multi-biotic Integrity Index for Dongting Lake, China

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Xing Wang

2015-06-01

Full Text Available A Lake Multi-biotic Integrity Index (LMII for the China’s second largest interior lake (Dongting Lake was developed to assess the water quality status using algal and macroinvertebrate metrics. Algae and benthic macroinvertebrate assemblages were sampled at 10 sections across 3 subregions of Dongting Lake. We used a stepwise process to evaluate properties of candidate metrics and selected ten for the LMII: Pampean diatom index, diatom quotient, trophic diatom index, relative abundance diatoms, Margalef index of algae, percent sensitive diatoms, % facultative individuals, % Chironomidae individuals, % predators individuals, and total number of macroinvertebrate taxa. We then tested the accuracy and feasibility of the LMII by comparing the correlation with physical-chemical parameters. Evaluation of the LMII showed that it discriminated well between reference and impaired sections and was strongly related to the major chemical and physical stressors (r = 0.766, P<0.001. The re-scored results from the 10 sections showed that the water quality of western Dongting Lake was good, while that of southern Dongting Lake was relatively good and whereas that of eastern Dongting Lake was poor. The discriminatory biocriteria of the LMII are suitable for the assessment of the water quality of Dongting Lake. Additionally, more metrics belonging to habitat, hydrology, physics and chemistry should be considered into the LMII, so as to establish comprehensive assessment system which can reflect the community structure of aquatic organisms, physical and chemical characteristics of water environment, human activities, and so on.

75 FR 17755 - Certificate of Alternative Compliance for the Offshore Supply Vessel GULF TIGER

Science.gov (United States)

2010-04-07

... Compliance for the Offshore Supply Vessel GULF TIGER AGENCY: Coast Guard, DHS. ACTION: Notice. SUMMARY: The... vessel GULF TIGER as required by 33 U.S.C. 1605(c) and 33 CFR 81.18. DATES: The Certificate of Alternate... for the h offshore supply vessel GULF TIGER. Full compliance with 72 COLREGS and the Inland Rules Act...

Danish Gulf War Veterans Revisited: No Evidence of Increased Sickness Absence or Reduced Labor Market Outcome After Deployment to the Persian Gulf.

Science.gov (United States)

Nissen, Lars Ravnborg; Stoltenberg, Christian; Nielsen, Anni B Sternhagen; Vedtofte, Mia S; Marott, Jacob L; Gyntelberg, Finn; Guldager, Bernadette

2016-11-01

To examine the assumption that postdeployment incidence of sickness and other absence from work are higher among Gulf War Veterans compared with nonveterans. A prospective registry study including a cohort of 721 Danish Gulf War Veterans and a control cohort of 3,629 nonveterans selected from the general Danish population. Outcome measures were up to 23 years postdeployment incidence of (1) long-term sickness absence and (2) long-term all types of absence from work. Long term with regard to sickness and other absence was defined as exceeding 8 weeks. The association between outcomes and information on deployment history was studied using time-to-event analysis. The index date was the return date from the last deployment to the Gulf. The follow-up period was the time from index date until April 27, 2014. As the main finding, no difference was found between veterans and nonveterans in the incidence rate of long-term sickness absence. After an initial short period (3 months) with elevated incidence rate of long-term absence from work among veterans, there was no difference between the cohorts. Among Danish Gulf War Veterans, no postdeployment increased risk of long-term sickness absence or long-term absence from work was found as compared with nonveterans. Reprint & Copyright © 2016 Association of Military Surgeons of the U.S.

Comparing Effects of Lake- and Watershed-Scale Influences on Communities of Aquatic Invertebrates in Shallow Lakes

Science.gov (United States)

Hanson, Mark A.; Herwig, Brian R.; Zimmer, Kyle D.; Fieberg, John; Vaughn, Sean R.; Wright, Robert G.; Younk, Jerry A.

2012-01-01

Constraints on lake communities are complex and are usually studied by using limited combinations of variables derived from measurements within or adjacent to study waters. While informative, results often provide limited insight about magnitude of simultaneous influences operating at multiple scales, such as lake- vs. watershed-scale. To formulate comparisons of such contrasting influences, we explored factors controlling the abundance of predominant aquatic invertebrates in 75 shallow lakes in western Minnesota, USA. Using robust regression techniques, we modeled relative abundance of Amphipoda, small and large cladocera, Corixidae, aquatic Diptera, and an aggregate taxon that combined Ephemeroptera-Trichoptera-Odonata (ETO) in response to lake- and watershed-scale characteristics. Predictor variables included fish and submerged plant abundance, linear distance to the nearest wetland or lake, watershed size, and proportion of the watershed in agricultural production. Among-lake variability in invertebrate abundance was more often explained by lake-scale predictors than by variables based on watershed characteristics. For example, we identified significant associations between fish presence and community type and abundance of small and large cladocera, Amphipoda, Diptera, and ETO. Abundance of Amphipoda, Diptera, and Corixidae were also positively correlated with submerged plant abundance. We observed no associations between lake-watershed variables and abundance of our invertebrate taxa. Broadly, our results seem to indicate preeminence of lake-level influences on aquatic invertebrates in shallow lakes, but historical land-use legacies may mask important relationships. PMID:22970275

Eutrophication potential of Payette Lake, Idaho

Science.gov (United States)

Woods, Paul F.

1997-01-01

Payette Lake was studied during water years 1995-96 to determine the 20.5-square-kilometer lake's assimilative capacity for nutrients and, thus, its eutrophication potential. The study included quantification of hydrologic and nutrient budgets, characterization of water quality in the limnetic and littoral zones, development of an empirical nutrient load/lake response model, and estimation of the limnological effects of a large-scale forest fire in the lake's 373-square-kilometer watershed during the autumn of 1994. Streamflow from the North Fork Payette River, the lake's primary tributary, delivered about 73 percent of the lake's inflow over the 2 years. Outflow from the lake, measured since 1908, was 128 and 148 percent of the long-term average in 1995 and 1996, respectively. The larger volumes of outflow reduced the long-term average water-

Geothermal Heat Flow in the Gulfs of California and Aden.

Science.gov (United States)

Von Herzen, R P

1963-06-14

Eighteen measurements in and near the gulfs of California and Aden indicate the geothermal flux is several times the world-wide mean of 1.2 x 10(-6) cal/cm(2) sec in both regions. Both gulfs closely coincide with the intersection of oceanic rises with continents and have likely been formed under tensional forces, which suggests an association with mantle convection currents.

75 FR 69921 - Gulf of Mexico Fishery Management Council; Public Meetings

Science.gov (United States)

2010-11-16

..., and the Essential Fish Habitat 5-Year Review Report. The Texas group is part of a three unit Habitat.... SUMMARY: The Gulf of Mexico Fishery Management Council will convene a public meeting of the Texas Habitat... FURTHER INFORMATION CONTACT: Jeff Rester, Habitat Support Specialist, Gulf States Marine Fisheries...

Microplastics in Taihu Lake, China.

Science.gov (United States)

Su, Lei; Xue, Yingang; Li, Lingyun; Yang, Dongqi; Kolandhasamy, Prabhu; Li, Daoji; Shi, Huahong

2016-09-01

In comparison with marine environments, the occurrence of microplastics in freshwater environments is less understood. In the present study, we investigated microplastic pollution levels during 2015 in Taihu Lake, the third largest Chinese lake located in one of the most developed areas of China. The abundance of microplastics reached 0.01 × 10(6)-6.8 × 10(6) items/km(2) in plankton net samples, 3.4-25.8 items/L in surface water, 11.0-234.6 items/kg dw in sediments and 0.2-12.5 items/g ww in Asian clams (Corbicula fluminea). The average abundance of microplastics was the highest in plankton net samples from the southeast area of the lake and in the sediments from the northwest area of the lake. The northwest area of the lake was the most heavily contaminated area of the lake, as indicated by chlorophyll-α and total phosphorus. The microplastics were dominated by fiber, 100-1000 μm in size and cellophane in composition. To our best knowledge, the microplastic levels measured in plankton net samples collected from Taihu Lake were the highest found in freshwater lakes worldwide. The ratio of the microplastics in clams to each sediment sample ranged from 38 to 3810 and was negatively correlated to the microplastic level in sediments. In brief, our results strongly suggest that high levels of microplastics occurred not only in water but also in organisms in Taihu Lake. Copyright © 2016 Elsevier Ltd. All rights reserved.

Gulf War

DEFF Research Database (Denmark)

Dalgaard-Nielsen, Anja

2003-01-01

As it became a non‐permanent member of the UN Security Council in January 2003, Germany stepped up its opposition to war with Iraq. The stage was set for a repeat of Germany's uncomfortable position during the 1991 Gulf War. At that time, as most of Germany's allies rallied behind Washington......, Germany made only financial contributions, and hundreds of thousands of Germans took to the streets to protest against the war. Yet, since 1991, Germany had come a long way in its attitudes towards military force. From a policy of complete abstention from military deployments beyond NATO's area (so...

Surface circulation in the Gulf of Cadiz: Model and mean flow structure

Science.gov (United States)

Peliz, Alvaro; Dubert, Jesus; Marchesiello, Patrick; Teles-Machado, Ana

2007-11-01

The mean flow structure of the Gulf of Cadiz is studied using a numerical model. The model consists of a set of one-way nested configurations attaining resolutions on the order of 2.6 km in the region of the Gulf of Cadiz. In the large-scale configuration, the entrainment of the Mediterranean Water is parameterized implicitly through a nudging term. In medium- and small-scale nested configurations, the Mediterranean outflow is introduced explicitly. The model reproduces all the known features of the Azores Current and of the circulation inside the Gulf of Cadiz. A realistic Mediterranean Undercurrent is generated and Meddies develop at proper depths on the southwest tip of the Iberian slope. The hypothesis that the Azores Current may generate in association with the Mediterranean outflow (β-plume theories) is confirmed by the model results. The time-mean flow is dominated by a cyclonic cell generated in the gulf which expands westward and has transports ranging from 4 to 5 Sv. The connection between the cell and the Azores Current is analyzed. At the scale of the Gulf, the time-mean flow cell is composed by the westward Mediterranean Undercurrent, and by a counterflow running eastward over the outer edge of the Mediterranean Undercurrent deeper vein, as the latter is forced downslope. This counterflow feeds the entrainment at the depths of the Mediterranean Undercurrent and the Atlantic inflow at shallower levels. Coastward and upslope of this recirculation cell, a second current running equatorward all the way along the northern part of the gulf is revealed. This current is a very robust model result that promotes continuity between the southwestern Iberian coast and the Strait of Gibraltar, and helps explain many observations and recurrent SST features of the Gulf of Cadiz.

The Red Sea and Gulf of Aden Basins

Science.gov (United States)

Bosworth, William; Huchon, Philippe; McClay, Ken

2005-10-01

We here summarize the evolution of the greater Red Sea-Gulf of Aden rift system, which includes the Gulfs of Suez and Aqaba, the Red Sea and Gulf of Aden marine basins and their continental margins, and the Afar region. Plume related basaltic trap volcanism began in Ethiopia, NE Sudan (Derudeb), and SW Yemen at ˜31 Ma, followed by rhyolitic volcanism at ˜30 Ma. Volcanism thereafter spread northward to Harrats Sirat, Hadan, Ishara-Khirsat, and Ar Rahat in western Saudi Arabia. This early magmatism occurred without significant extension, and continued to ˜25 Ma. Much of the Red Sea and Gulf of Aden region was at or near sea level at this time. Starting between ˜29.9 and 28.7 Ma, marine syn-tectonic sediments were deposited on continental crust in the central Gulf of Aden. At the same time the Horn of Africa became emergent. By ˜27.5-23.8 Ma a small rift basin was forming in the Eritrean Red Sea. At approximately the same time (˜25 Ma), extension and rifting commenced within Afar itself. At ˜24 Ma, a new phase of volcanism, principally basaltic dikes but also layered gabbro and granophyre bodies, appeared nearly synchronously throughout the entire Red Sea, from Afar and Yemen to northern Egypt. This second phase of magmatism was accompanied in the Red Sea by strong rift-normal extension and deposition of syn-tectonic sediments, mostly of marine and marginal marine affinity. Sedimentary facies were laterally heterogeneous, being comprised of inter-fingering siliciclastics, evaporite, and carbonate. Throughout the Red Sea, the principal phase of rift shoulder uplift and rapid syn-rift subsidence followed shortly thereafter at ˜20 Ma. Water depths increased dramatically and sedimentation changed to predominantly Globigerina-rich marl and deepwater limestone. Within a few million years of its initiation in the mid-Oligocene the Gulf of Aden continental rift linked the Owen fracture zone (oceanic crust) with the Afar plume. The principal driving force for extension

Influence of monsoonal winds on chlorophyll-α distribution in the Beibu Gulf.

Directory of Open Access Journals (Sweden)

Chunyan Shen

Full Text Available The influence of seasonal, monsoonal winds on the temporal and spatial variability of chlorophyll-a (chl-a in the Beibu Gulf is studied based on long-term satellite data of sea surface winds, chl-a concentration and sea surface temperature (SST and in-situ observations for the years from 2002 to 2014. The analysis results indicated that under northeasterly monsoonal winds, chl-a concentrations were substantially elevated in most area of the Beibu Gulf, with a high chl-a concentration (>2 mg m-3 patch extending southwestward from the coastal water of the northeastern Gulf, consistent with the winter wind pattern. Meanwhile, the spatial distribution of high chl-a concentration is correlated with low SST in the northeastern Gulf. In the southern Gulf, there was generally low chl-a, except in the coastal waters southwest of Hainan Island. Here, the upwelling cold water prevails outside the mouth of the Beibu Gulf, driven by the southwesterly monsoonal winds and the runoff from the Changhua River, as implied by low observed SST. Correlation analysis indicated the chl-a concentration was strongly modulated by wind speed (r = 0.63, p0.7, p<0.001. Integrated analysis also showed that stratification is weak and mixing is strong in winter as affected by the high wind speed, which suggests that the wind-induced mixing is a dominant mechanism for entrainment of nutrients and the spatial distribution of chl-a in winter.

From top to bottom: Do Lake Trout diversify along a depth gradient in Great Bear Lake, NT, Canada?

Science.gov (United States)

Chavarie, Louise; Howland, Kimberly L; Harris, Les N; Hansen, Michael J; Harford, William J; Gallagher, Colin P; Baillie, Shauna M; Malley, Brendan; Tonn, William M; Muir, Andrew M; Krueger, Charles C

2018-01-01

Depth is usually considered the main driver of Lake Trout intraspecific diversity across lakes in North America. Given that Great Bear Lake is one of the largest and deepest freshwater systems in North America, we predicted that Lake Trout intraspecific diversity to be organized along a depth axis within this system. Thus, we investigated whether a deep-water morph of Lake Trout co-existed with four shallow-water morphs previously described in Great Bear Lake. Morphology, neutral genetic variation, isotopic niches, and life-history traits of Lake Trout across depths (0-150 m) were compared among morphs. Due to the propensity of Lake Trout with high levels of morphological diversity to occupy multiple habitat niches, a novel multivariate grouping method using a suite of composite variables was applied in addition to two other commonly used grouping methods to classify individuals. Depth alone did not explain Lake Trout diversity in Great Bear Lake; a distinct fifth deep-water morph was not found. Rather, Lake Trout diversity followed an ecological continuum, with some evidence for adaptation to local conditions in deep-water habitat. Overall, trout caught from deep-water showed low levels of genetic and phenotypic differentiation from shallow-water trout, and displayed higher lipid content (C:N ratio) and occupied a higher trophic level that suggested an potential increase of piscivory (including cannibalism) than the previously described four morphs. Why phenotypic divergence between shallow- and deep-water Lake Trout was low is unknown, especially when the potential for phenotypic variation should be high in deep and large Great Bear Lake. Given that variation in complexity of freshwater environments has dramatic consequences for divergence, variation in the complexity in Great Bear Lake (i.e., shallow being more complex than deep), may explain the observed dichotomy in the expression of intraspecific phenotypic diversity between shallow- vs. deep-water habitats

From top to bottom: Do Lake Trout diversify along a depth gradient in Great Bear Lake, NT, Canada?

Science.gov (United States)

Chavarie, Louise; Howland, Kimberly L.; Harris, Les N.; Hansen, Michael J.; Harford, William J.; Gallagher, Colin P.; Baillie, Shauna M.; Malley, Brendan; Tonn, William M.; Muir, Andrew M.; Krueger, Charles C.

2018-01-01

Depth is usually considered the main driver of Lake Trout intraspecific diversity across lakes in North America. Given that Great Bear Lake is one of the largest and deepest freshwater systems in North America, we predicted that Lake Trout intraspecific diversity to be organized along a depth axis within this system. Thus, we investigated whether a deep-water morph of Lake Trout co-existed with four shallow-water morphs previously described in Great Bear Lake. Morphology, neutral genetic variation, isotopic niches, and life-history traits of Lake Trout across depths (0–150 m) were compared among morphs. Due to the propensity of Lake Trout with high levels of morphological diversity to occupy multiple habitat niches, a novel multivariate grouping method using a suite of composite variables was applied in addition to two other commonly used grouping methods to classify individuals. Depth alone did not explain Lake Trout diversity in Great Bear Lake; a distinct fifth deep-water morph was not found. Rather, Lake Trout diversity followed an ecological continuum, with some evidence for adaptation to local conditions in deep-water habitat. Overall, trout caught from deep-water showed low levels of genetic and phenotypic differentiation from shallow-water trout, and displayed higher lipid content (C:N ratio) and occupied a higher trophic level that suggested an potential increase of piscivory (including cannibalism) than the previously described four morphs. Why phenotypic divergence between shallow- and deep-water Lake Trout was low is unknown, especially when the potential for phenotypic variation should be high in deep and large Great Bear Lake. Given that variation in complexity of freshwater environments has dramatic consequences for divergence, variation in the complexity in Great Bear Lake (i.e., shallow being more complex than deep), may explain the observed dichotomy in the expression of intraspecific phenotypic diversity between shallow- vs. deep-water habitats

Predicting Maximum Lake Depth from Surrounding Topography

Science.gov (United States)

Lake volume aids understanding of the physical and ecological dynamics of lakes, yet is often not readily available. The data needed to calculate lake volume (i.e. bathymetry) are usually only collected on a lake by lake basis and are difficult to obtain across broad regions. ...

Reconstructing Heat Fluxes Over Lake Erie During the Lake Effect Snow Event of November 2014

Science.gov (United States)

Fitzpatrick, L.; Fujisaki-Manome, A.; Gronewold, A.; Anderson, E. J.; Spence, C.; Chen, J.; Shao, C.; Posselt, D. J.; Wright, D. M.; Lofgren, B. M.; Schwab, D. J.

2017-12-01

The extreme North American winter storm of November 2014 triggered a record lake effect snowfall (LES) event in southwest New York. This study examined the evaporation from Lake Erie during the record lake effect snowfall event, November 17th-20th, 2014, by reconstructing heat fluxes and evaporation rates over Lake Erie using the unstructured grid, Finite-Volume Community Ocean Model (FVCOM). Nine different model runs were conducted using combinations of three different flux algorithms: the Met Flux Algorithm (COARE), a method routinely used at NOAA's Great Lakes Environmental Research Laboratory (SOLAR), and the Los Alamos Sea Ice Model (CICE); and three different meteorological forcings: the Climate Forecast System version 2 Operational Analysis (CFSv2), Interpolated observations (Interp), and the High Resolution Rapid Refresh (HRRR). A few non-FVCOM model outputs were also included in the evaporation analysis from an atmospheric reanalysis (CFSv2) and the large lake thermodynamic model (LLTM). Model-simulated water temperature and meteorological forcing data (wind direction and air temperature) were validated with buoy data at three locations in Lake Erie. The simulated sensible and latent heat fluxes were validated with the eddy covariance measurements at two offshore sites; Long Point Lighthouse in north central Lake Erie and Toledo water crib intake in western Lake Erie. The evaluation showed a significant increase in heat fluxes over three days, with the peak on the 18th of November. Snow water equivalent data from the National Snow Analyses at the National Operational Hydrologic Remote Sensing Center showed a spike in water content on the 20th of November, two days after the peak heat fluxes. The ensemble runs presented a variation in spatial pattern of evaporation, lake-wide average evaporation, and resulting cooling of the lake. Overall, the evaporation tended to be larger in deep water than shallow water near the shore. The lake-wide average evaporations

Gulf Canada's Russian joint venture

International Nuclear Information System (INIS)

Motyka, D.

1992-01-01

After three years of evaluating prospects and negotiating with government and industry representatives, Gulf Canada established its first joint venture in the Russian Federation with Komineft, a production association from the Komi autonomous republic. Komineft has a 50% share of the venture, and the rest is shared equally between Gulf and British Gas. The operating area is at the Vozey and Upper Vozey fields in the Timan-Pechora Basin, some 1,500 km northeast of Moscow just inside the Arctic Circle. An attractive feature of the Upper Vozey project is low development costs of ca $2/bbl. In the Vozey field, the venture will set up an enhanced oil recovery demonstration project to test techniques perfected in Alberta. About 60 Canadians are involved on the project, and headquarters are in Usinsk, ca 100 km south of the oil fields. In the first half of 1992, oil production in the first phase of the venture averaged around 10,000 bbl/d and continues to increase

Environmental emergency in Persian Gulf

International Nuclear Information System (INIS)

Zanini, G.

1991-01-01

This paper gives an environmental damage report for the Kuwait-Persian Gulf area that has been affected by the Gulf War oil well fires and the release of oil into the sea. The report was prepared by members of an ENEA (Italian Commission for New Technologies, Energy and the Environment)/Friends of the Earth scientific mission whose aim was to assess the damage to terrestrial and aquatic ecosystems and to develop short and long terms programs of damage containment and environmental restoration. With regard to shore-line clean-up operations, the mission noted the scarce use of manpower, 500 versus 11,000 for the Exxon Valdez spill. Seventy-five per cent of the surface of Kuwait has been covered with a fine spray of petroleum and ashes borne by turbulent winds. Efforts are being made to establish a climate model, which would take into account the effects of the altered environmental conditions, to forecast the local transport of the pollutants

Alaska, Gulf spills share similarities

International Nuclear Information System (INIS)

Usher, D.

1991-01-01

The accidental Exxon Valdez oil spill in Alaska and the deliberate dumping of crude oil into the Persian Gulf as a tactic of war contain both glaring differences and surprising similarities. Public reaction and public response was much greater to the Exxon Valdez spill in pristine Prince William Sound than to the war-related tragedy in the Persian Gulf. More than 12,000 workers helped in the Alaskan cleanup; only 350 have been involved in Kuwait. But in both instances, environmental damages appear to be less than anticipated. Natures highly effective self-cleansing action is primarily responsible for minimizing the damages. One positive action growing out of the two incidents is increased international cooperation and participation in oil-spill clean-up efforts. In 1990, in the aftermath of the Exxon Valdez spill, 94 nations signed an international accord on cooperation in future spills. The spills can be historic environmental landmarks leading to creation of more sophisticated response systems worldwide

Hydrologic-energy balance constraints on the Holocene lake-level history of lake Titicaca, South America

Energy Technology Data Exchange (ETDEWEB)

Rowe, H.D.; Dunbar, R.B. [Stanford University, Geological and Environmental Sciences, Stanford, CA (United States)

2004-09-01

A basin-scale hydrologic-energy balance model that integrates modern climatological, hydrological, and hypsographic observations was developed for the modern Lake Titicaca watershed (northern Altiplano, South America) and operated under variable conditions to understand controls on post-glacial changes in lake level. The model simulates changes in five environmental variables (air temperature, cloud fraction, precipitation, relative humidity, and land surface albedo). Relatively small changes in three meteorological variables (mean annual precipitation, temperature, and/or cloud fraction) explain the large mid-Holocene lake-level decrease ({proportional_to}85 m) inferred from seismic reflection profiling and supported by sediment-based paleoproxies from lake sediments. Climatic controls that shape the present-day Altiplano and the sediment-based record of Holocene lake-level change are combined to interpret model-derived lake-level simulations in terms of changes in the mean state of ENSO and its impact on moisture transport to the Altiplano. (orig.)

Hydrologic-energy balance constraints on the Holocene lake-level history of lake Titicaca, South America

Science.gov (United States)

Rowe, H. D.; Dunbar, R. B.

2004-09-01

A basin-scale hydrologic-energy balance model that integrates modern climatological, hydrological, and hypsographic observations was developed for the modern Lake Titicaca watershed (northern Altiplano, South America) and operated under variable conditions to understand controls on post-glacial changes in lake level. The model simulates changes in five environmental variables (air temperature, cloud fraction, precipitation, relative humidity, and land surface albedo). Relatively small changes in three meteorological variables (mean annual precipitation, temperature, and/or cloud fraction) explain the large mid-Holocene lake-level decrease (˜85 m) inferred from seismic reflection profiling and supported by sediment-based paleoproxies from lake sediments. Climatic controls that shape the present-day Altiplano and the sediment-based record of Holocene lake-level change are combined to interpret model-derived lake-level simulations in terms of changes in the mean state of ENSO and its impact on moisture transport to the Altiplano.

In-Lake Processes Offset Increased Terrestrial Inputs of Dissolved Organic Carbon and Color to Lakes

Science.gov (United States)

Köhler, Stephan J.; Kothawala, Dolly; Futter, Martyn N.; Liungman, Olof; Tranvik, Lars

2013-01-01

Increased color in surface waters, or browning, can alter lake ecological function, lake thermal stratification and pose difficulties for drinking water treatment. Mechanisms suggested to cause browning include increased dissolved organic carbon (DOC) and iron concentrations, as well as a shift to more colored DOC. While browning of surface waters is widespread and well documented, little is known about why some lakes resist it. Here, we present a comprehensive study of Mälaren, the third largest lake in Sweden. In Mälaren, the vast majority of water and DOC enters a western lake basin, and after approximately 2.8 years, drains from an eastern basin. Despite 40 years of increased terrestrial inputs of colored substances to western lake basins, the eastern basin has resisted browning over this time period. Here we find the half-life of iron was far shorter (0.6 years) than colored organic matter (A420 ; 1.7 years) and DOC as a whole (6.1 years). We found changes in filtered iron concentrations relate strongly to the observed loss of color in the western basins. In addition, we observed a substantial shift from colored DOC of terrestrial origin, to less colored autochthonous sources, with a substantial decrease in aromaticity (-17%) across the lake. We suggest that rapid losses of iron and colored DOC caused the limited browning observed in eastern lake basins. Across a wider dataset of 69 Swedish lakes, we observed greatest browning in acidic lakes with shorter retention times (< 1.5 years). These findings suggest that water residence time, along with iron, pH and colored DOC may be of central importance when modeling and projecting changes in brownification on broader spatial scales. PMID:23976946

Visual observations of historical lake trout spawning grounds in western Lake Huron

Science.gov (United States)

Nester, Robert T.; Poe, Thomas P.

1987-01-01

Direct underwater video observations were made of the bottom substrates at 12 spawning grounds formerly used by lake trout Salvelinus namaycush in western Lake Huron to evaluate their present suitability for successful reproduction by lake trout. Nine locations examined north of Saginaw Bay in the northwestern end of the lake are thought to provide the best spawning habitat. The substrate at these sites consisted of angular rough cobble and rubble with relatively deep interstitial spaces (a?Y 0.5 m), small amounts of fine sediments, and little or no periphytic growth. Conditions at the three other sampling locations south of Saginaw Bay seemed much less suitable for successful reproduction based on the reduced area of high-quality substrate, shallow interstitial spaces, high infiltration of fine sediments, and greater periphytic growth.

Patterns of Illness and Care Before Deployment to the Persian Gulf War

National Research Council Canada - National Science Library

Miller, Richard

2001-01-01

...) Comprehensive Clinical Evaluation Program (CCEP) upon returning from the Persian Gulf War have patterns of illness and medical care seeking during the year prior to deployment to the Persian Gulf that differ from those of comparison groups of Army...

Patterns of Illness and Care Before Deployment to the Persian Gulf War

National Research Council Canada - National Science Library

Miller, Richard

2002-01-01

...) Comprehensive Clinical Evaluation Program (CCEP) upon returning from the Persian Gulf War have patterns of illness and medical care seeking during the year prior to deployment to the Persian Gulf that differ from those of comparison groups of Army...

Evaluation of ground-water flow and hydrologic budget for Lake Five-O, a seepage lake in northwestern Florida

Science.gov (United States)

Grubbs, J.W.

1995-01-01

Temporal and spatial distributions of ground-water inflow to, and leakage from Lake Five-O, a softwater, seepage lake in northwestern Florida, were evaluated using hydrologic data and simulation models of the shallow ground-water system adjacent to the lake. The simulation models indicate that ground-water inflow to the lake and leakage from the lake to the ground-water system are the dominant components in the total inflow (precipitation plus ground-water inflow) and total outflow (evaporation plus leakage) budgets of Lake Five-O. Simlulated ground-water inflow and leakage were approximately 4 and 5 times larger than precipitation inputs and evaporative losses, respectively, during calendar years 1989-90. Exchanges of water between Lake Five-O and the ground-water system were consistently larger than atmospheric-lake exchanges. A consistent pattern of shallow ground-water inflow and deep leakage was also evident throughout the study period. The mean time of travel from ground-water that discharges at Lake Five-O (time from recharge at the water table to discharge at the lake) was estimated to be within a range of 3 to 6 years. Flow-path evaluations indicated that the intermediate confining unit probably has a negligible influence on the geochemistry of ground-water inflow to Lake Five-O. The hydrologic budgets and flow-path evaluations provide critical information for developing geochemical budgets for Lake Five-O and for improving the understanding of the relative importance of various processes that regulate the acid-neutralizing capacity of softwater seepage lakes in Florida.

Seismic architecture and lithofacies of turbidites in Lake Mead (Arizona and Nevada, U.S.A.), an analogue for topographically complex basins

Science.gov (United States)

Twichell, D.C.; Cross, V.A.; Hanson, A.D.; Buck, B.J.; Zybala, J.G.; Rudin, M.J.

2005-01-01

Turbidites, which have accumulated in Lake Mead since completion of the Hoover Dam in 1935, have been mapped using high-resolution seismic and coring techniques. This lake is an exceptional natural laboratory for studying fine-grained turbidite systems in complex topographic settings. The lake comprises four relatively broad basins separated by narrow canyons, and turbidity currents run the full length of the lake. The mean grain size of turbidites is mostly coarse silt, and the sand content decreases from 11-30% in beds in the easternmost basin nearest the source to 3-14% in the central basins to 1-2% in the most distal basin. Regionally, the seismic amplitude mimics the core results and decreases away from the source. The facies and morphology of the sediment surface varies between basins and suggests a regional progression from higher-energy and possibly channelized flows in the easternmost basin to unchannelized flows in the central two basins to unchannelized flows that are ponded by the Hoover Dam in the westernmost basin. At the local scale, turbidites are nearly flat-lying in the central two basins, but here the morphology of the basin walls strongly affects the distribution of facies. One of the two basins is relatively narrow, and in sinuous sections reflection amplitude increases toward the outsides of meanders. Where a narrow canyon debouches into a broad basin, reflection amplitude decreases radially away from the canyon mouth and forms a fan-like deposit. The fine-grained nature of the turbidites in the most distal basin and the fact that reflections drape the underlying pre-impoundment surface suggest ponding here. The progression from ponding in the most distal basin to possibly channelized flows in the most proximal basin shows in plan view a progression similar to the stratigraphic progression documented in several minibasins in the Gulf of Mexico. Copyright ?? 2005, SEPM (Society for Sedimentary Geology).

Great Lakes Science Center

Data.gov (United States)

Federal Laboratory Consortium — Since 1927, Great Lakes Science Center (GLSC) research has provided critical information for the sound management of Great Lakes fish populations and other important...

Blood Biomarkers of Chronic Inflammation in Gulf War Illness.

Directory of Open Access Journals (Sweden)

Gerhard J Johnson

Full Text Available More than twenty years following the end of the 1990-1991 Gulf War it is estimated that approximately 300,000 veterans of this conflict suffer from an unexplained chronic, multi-system disorder known as Gulf War Illness (GWI. The etiology of GWI may be exposure to chemical toxins, but it remains only partially defined, and its case definition is based only on symptoms. Objective criteria for the diagnosis of GWI are urgently needed for diagnosis and therapeutic research.This study was designed to determine if blood biomarkers could provide objective criteria to assist diagnosis of GWI.A surveillance study of 85 Gulf War Veteran volunteers identified from the Department of Veterans Affairs Minnesota Gulf War registry was performed. All subjects were deployed to the Gulf War. Fifty seven subjects had GWI defined by CDC criteria, and 28 did not have symptomatic criteria for a diagnosis of GWI. Statistical analyses were performed on peripheral blood counts and assays of 61 plasma proteins using the Mann-Whitney rank sum test to compare biomarker distributions and stepwise logistic regression to formulate a diagnostic model.Lymphocyte, monocyte, neutrophil, and platelet counts were higher in GWI subjects. Six serum proteins associated with inflammation were significantly different in GWI subjects. A diagnostic model of three biomarkers-lymphocytes, monocytes, and C reactive protein-had a predicted probability of 90% (CI 76-90% for diagnosing GWI when the probability of having GWI was above 70%.The results of the current study indicate that inflammation is a component of the pathobiology of GWI. Analysis of the data resulted in a model utilizing three readily measurable biomarkers that appears to significantly augment the symptom-based case definition of GWI. These new observations are highly relevant to the diagnosis of GWI, and to therapeutic trials.

Changes in the dreissenid community in the lower Great Lakes with emphasis on southern Lake Ontario

Science.gov (United States)

Mills, Edward L.; Chrisman, Jana R.; Baldwin, Brad; Owens, Randall W.; O'Gorman, Robert; Howell, Todd; Roseman, Edward F.; Raths, Melinda K.

1999-01-01

A field study was conducted in the lower Great Lakes to assess changes in spatial distribution and population structure of dreissenid mussel populations. More specifically, the westward range expansion of quagga mussel into western Lake Erie and toward Lake Huron was investigated and the shell size, density, and biomass of zebra and quagga mussel with depth in southern Lake Ontario in 1992 and 1995 were compared. In Lake Erie, quagga mussel dominated the dreissenid community in the eastern basin and zebra mussel dominated in the western basin. In southern Lake Ontario, an east to west gradient was observed with the quagga mussel dominant at western sites and zebra mussel dominant at eastern locations. Mean shell size of quagga mussel was generally larger than that of zebra mussel except in western Lake Erie and one site in eastern Lake Erie. Although mean shell size and our index of numbers and biomass of both dreissenid species increased sharply in southern Lake Ontario between 1992 and 1995, the increase in density and biomass was much greater for quagga mussels over the 3-year period. In 1995, zebra mussels were most abundant at 15 to 25 m whereas the highest numbers and biomass of quagga mussel were at 35 to 45 m. The quagga mussel is now the most abundant dreissenid in areas of southern Lake Ontario where the zebra mussel was once the most abundant dreissenid; this trend parallels that observed for dreissenid populations in the Dneiper River basin in the Ukraine.

Egg fatty acid composition from lake trout fed two Lake Michigan prey fish species.

Science.gov (United States)

Honeyfield, D.C.; Fitzsimons, J.D.; Tillitt, D.E.; Brown, S.B.

2009-01-01

We previously demonstrated that there were significant differences in the egg thiamine content in lake trout Salvelinus namaycush fed two Lake Michigan prey fish (alewife Alosa pseudoharengus and bloater Coregonus hoyi). Lake trout fed alewives produced eggs low in thiamine, but it was unknown whether the consumption of alewives affected other nutritionally important components. In this study we investigated the fatty acid composition of lake trout eggs when females were fed diets that resulted in different egg thiamine concentrations. For 2 years, adult lake trout were fed diets consisting of four combinations of captured alewives and bloaters (100% alewives; 65% alewives, 35% bloaters; 35% alewives, 65% bloaters; and 100% bloaters). The alewife fatty acid profile had higher concentrations of arachidonic acid and total omega-6 fatty acids than the bloater profile. The concentrations of four fatty acids (cis-13, 16-docosadienoic, eicosapentaenoic, docosapentaenoic, and docosahexaenoic acids) were higher in bloaters than in alewives. Although six fatty acid components were higher in lake trout eggs in 2001 than in 2000 and eight fatty acids were lower, diet had no effect on any fatty acid concentration measured in lake trout eggs in this study. Based on these results, it appears that egg fatty acid concentrations differ between years but that the egg fatty acid profile does not reflect the alewife-bloater mix in the diet of adults. The essential fatty acid content of lake trout eggs from females fed alewives and bloaters appears to be physiologically regulated and adequate to meet the requirements of developing embryos.

Why is Improving Water Quality in the Gulf of Mexico so Critical?

Science.gov (United States)

The EPA regional offices and the Gulf of Mexico Program work with Gulf States to continue to maximize the efficiency and utility of water quality monitoring efforts for local managers by coordinating and standardizing state and federal water quality data

Evaporation variability of Nam Co Lake in the Tibetan Plateau and its role in recent rapid lake expansion

Science.gov (United States)

Ma, Ning; Szilagyi, Jozsef; Niu, Guo-Yue; Zhang, Yinsheng; Zhang, Teng; Wang, Binbin; Wu, Yanhong

2016-06-01

Previous studies have shown that the majority of the lakes in the Tibetan Plateau (TP) started to expand rapidly since the late 1990s. However, the causes are still not well known. For Nam Co, being a closed lake with no outflow, evaporation (EL) over the lake surface is the only way water may leave the lake. Therefore, quantifying EL is key for investigating the mechanism of lake expansion in the TP. EL can be quantified by Penman- and/or bulk-transfer-type models, requiring only net radiation, temperature, humidity and wind speed for inputs. However, interpolation of wind speed data may be laden with great uncertainty due to extremely sparse ground meteorological observations, the highly heterogeneous landscape and lake-land breeze effects. Here, evaporation of Nam Co Lake was investigated within the 1979-2012 period at a monthly time-scale using the complementary relationship lake evaporation (CRLE) model which does not require wind speed data. Validations by in-situ observations of E601B pan evaporation rates at the shore of Nam Co Lake as well as measured EL over an adjacent small lake using eddy covariance technique suggest that CRLE is capable of simulating EL well since it implicitly considers wind effects on evaporation via its vapor transfer coefficient. The multi-year average of annual evaporation of Nam Co Lake is 635 mm. From 1979 to 2012, annual evaporation of Nam Co Lake expressed a very slight decreasing trend. However, a more significant decrease in EL occurred during 1998-2008 at a rate of -12 mm yr-1. Based on water-level readings, this significant decrease in lake evaporation was found to be responsible for approximately 4% of the reported rapid water level increase and areal expansion of Nam Co Lake during the same period.

The influence of carbon exchange of a large lake on regional tracer-transport inversions: results from Lake Superior

International Nuclear Information System (INIS)

Vasys, Victoria N; Desai, Ankur R; McKinley, Galen A; Bennington, Val; Michalak, Anna M; Andrews, Arlyn E

2011-01-01

Large lakes may constitute a significant component of regional surface-atmosphere fluxes, but few efforts have been made to quantify these fluxes. Tracer-transport inverse models that infer the CO 2 flux from the atmospheric concentration typically assume that the influence from large lakes is negligible. CO 2 observations from a tall tower in Wisconsin segregated by wind direction suggested a CO 2 signature from Lake Superior. To further investigate this difference, source-receptor influence functions derived using a mesoscale transport model were applied and results revealed that air masses sampled by the tower have a transit time over the lake, primarily in winter when the total lake influence on the tower can exceed 20% of the total influence of the regional domain. When the influence functions were convolved with air-lake fluxes estimated from a physical-biogeochemical lake model, the overall total contribution of lake fluxes to the tall tower CO 2 were mostly negligible, but potentially detectable in certain periods of fall and winter when lake carbon exchange can be strong and land carbon efflux weak. These findings suggest that large oligotrophic lakes would not significantly influence inverse models that incorporate tall tower CO 2 .

Submerged Grove in Lake Onogawa

OpenAIRE

Sato, Yasuhiro; Nakamura, Soken; Ochiai, Masahiro

1996-01-01

Abstract : The first record by ultrasonic echo sounding on the distribution of the submerged standing trees on the bottom of Lake Onogawa is presented. Lake Onogawa is a dammed lake formed at the time of the eruption of the volcano Mt.Bandai in 1888. Since then the original vegetation of the dammed valley has remained submerged. Many submerged standing trees are distributed on the bottom within about 600m from the northeast end of the lake. The density of the trees in this area is sufficient ...

L-Lake zooplankton: L-Lake/Steel Creek Biological Monitoring Program, November 1985--December 1991

Energy Technology Data Exchange (ETDEWEB)

Bowers, J.A. [Westinghouse Savannah River Co., Aiken, SC (United States); Bowen, M. [Normandeau Associates, Inc., New Ellenton, SC (United States)

1992-03-01

The L- Lake Biological Monitoring Program was designed to meet environmental regulatory requirements associated with the restart of L-Reactor and address portions of Section 316(a) of the Clean Water Act, which requires an applicant for a discharge permit to provide scientific evidence that the discharge causes no significant impact on the indigenous ecosystem. The Department of Energy (DOE) must demonstrate that the discharge of L-Reactor affluent into L Lake will not inhibit the eventual establishment of a ``Balanced Biological Community`` (BBC) in at least 50% of the lake. This report details results of monitoring zooplankton populations in L-Lake.

L-Lake zooplankton: L-Lake/Steel Creek Biological Monitoring Program, November 1985--December 1991

International Nuclear Information System (INIS)

Bowers, J.A.; Bowen, M.

1992-03-01

The L- Lake Biological Monitoring Program was designed to meet environmental regulatory requirements associated with the restart of L-Reactor and address portions of Section 316(a) of the Clean Water Act, which requires an applicant for a discharge permit to provide scientific evidence that the discharge causes no significant impact on the indigenous ecosystem. The Department of Energy (DOE) must demonstrate that the discharge of L-Reactor affluent into L Lake will not inhibit the eventual establishment of a ''Balanced Biological Community'' (BBC) in at least 50% of the lake. This report details results of monitoring zooplankton populations in L-Lake

Effectiveness of Acupuncture in the Treatment of Gulf War Illness

Science.gov (United States)

2013-01-01

325. 7 Wigers SH, Stiles TC, Vogael PA. Effects of aerobic exercise versus stress management treatment in fibromyalgia : a 4.5 year prospective study... Treatment of Gulf War Illness PRINCIPAL INVESTIGATOR: Lisa Conboy, M.A., M.S., ScD...December 2012 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Effectiveness of Acupuncture in the Treatment of Gulf War Illness 5b. GRANT NUMBER W81XWH

The consequences and hazards of depleted uranium weapons used by US army since gulf war

International Nuclear Information System (INIS)

Mao Yongze

1999-01-01

Military equipment and development of depleted uranium weapon in USA, the depleted uranium weapon used in gulf war by USA army, personnel irradiation in the gulf war, and the protection in the gulf war are introduced. The radioactivity, radioactive characteristics, chemical toxicity and hazard of the depleted uranium are also introduced

LAKE-0: a model for the simulation of nuclides transfer in lake scenarios

Energy Technology Data Exchange (ETDEWEB)

Garcia-Olivares, A.; Aguero, A.; Pinedo, P.

1994-07-01

This report presents documentation and a user's manual for the program LAKE-0, a mathematical model of nuclides transfer in lake scenarios. Mathematical equations and physical principles used to develop the code are presented in section 2. The program use is presented in section 3 including input data sets and output data. Section 4 presents two example problems, and some results. The complete program listing including comments is presented in Appendix A. Nuclides are assumed to center the lake via atmospheric deposition and carried by the water runoff and the dragged sediments from the adjacent catchment. The dynamics of the nuclides inside the lake is based in the model proposed by Codell (11) as modified in (5). The removal of concentration from the lake water is due to out flow from the lake and to the transfer of activity to the button sediments. The model has been applied to the Esthwaite Water (54 degree celsius 2 l'N, 03 degree celsius 00'W at 65 m. asi.) in the frame of the VAMP Aquatic Working Group (8) and to Devoke Water (5 21.5'N, 03H8'W at 230 m. asi.). (Author). 13 refs.

Heavy metal, trace element and petroleum hydrocarbon pollution in the Arabian Gulf: Review

OpenAIRE

Afnan Mahmood Freije

2015-01-01

The Arabian Gulf environmental status was assessed based on studies conducted in Bahrain, Kuwait, Oman, Saudi Arabia, Qatar, and United Arab Emirates (UAE) during 1983–2011. This review examines all sorts of pollutions in the Arabian Gulf area over the last three decades. Approximately 50 published studies were reviewed in order to determine the pollution status in the Arabian Gulf regarding heavy metals and organic substances. Three types of environmental pollutions including marine and coas...

Isotope techniques in lake water studies

International Nuclear Information System (INIS)

Gourcy, L.

1999-01-01

Freshwater lakes are among the most easily exploitable freshwater resources. Lakes are also recognized as major sedimentological features in which stored material can be used to study recent climate and pollution evolution. To adequately preserve these important landscape features, and to use them as climatic archives, an improved understanding of processes controlling their hydrologic and bio-geochemical environments if necessary. This article briefly describes the IAEA activities related to the study of lakes in such areas as lake budget, lake dynamics, water contamination, and paleolimnological investigations

78 FR 69803 - Drawbridge Operation Regulations; Gulf Intracoastal Waterway, Venice, FL

Science.gov (United States)

2013-11-21

...-AA09 Drawbridge Operation Regulations; Gulf Intracoastal Waterway, Venice, FL AGENCY: Coast Guard, DHS... that governs the Hatchett Creek (US-41) Twin Bridges, Gulf Intracoastal Waterway mile 56.9, Venice, FL... mile 56.9 at Venice, FL as listed in Sec. 117.287(b), provides the draw of the Hatchett Creek (US-41...

Lake Erie and Lake Michigan zebra mussel settlement monitoring and implications for chlorination treatment

International Nuclear Information System (INIS)

Demoss, D.; Mendelsberg, J.I.

1992-01-01

This paper reports on the 1991 zebra mussel veliger settlement monitoring program undertaken to record and evaluate zebra mussel veliger settlement in Lake Erie and Lake Michigan. Studies by Dr. Gerald Mackie of Canada in 1990 indicated veliger settlement may be occurring primarily during short time periods every season corresponding with warmer water temperatures. Veliger settlement monitoring was performed using a plexiglass sampler apparatus. The samplers were simple in design and consisted of a 20-inch-square plexiglass base panel with thirty-six 1 inch x 3 inch clear plexiglass microscope slides attached. The results of the monitoring program indicate the existence of preferential settlement periods for veligers correlating with sustained lake water temperatures above 70 degrees F. Veliger settlement concentrations in the south basin of Lake Michigan appear to be similar to those in western Lake Erie

Lake or Pond WBID

Data.gov (United States)

Vermont Center for Geographic Information — The VT DEC (Vermont Department of Environmental Conservation) manages an inventory of lake and pond information. The "Lakes and Ponds Inventory" stores the Water...

Survey to assess Persian Gulf spill effects

International Nuclear Information System (INIS)

Anon.

1992-01-01

This paper reports that an international group is poised for an extensive survey of the Persian Gulf, including an assessment of the long term effects of last year's oil spill, a legacy of the Persian Gulf war. Saudi Arabia plans a $450 million cleanup program on beaches fouled by the massive spill. Plans for the survey were disclosed by the United National Educational, Scientific and Cultural Organization (Unesco). It is to be carried out under the auspices of the Regional Organization for the Protection of the Marine Environment (Ropme), Unesco's Intergovernmental Oceanographic Commission, and the U.S. National Oceanic and Atmospheric Administration. Ropme member countries are Bahrain, Iran, Iraq, Kuwait, Qatar, Saudi Arabia, and the United Arab Emirates

On depleted uranium: gulf war and Balkan syndrome.

Science.gov (United States)

Duraković, A

2001-04-01

The complex clinical symptomatology of chronic illnesses, commonly described as Gulf War Syndrome, remains a poorly understood disease entity with diversified theories of its etiology and pathogenesis. Several causative factors have been postulated, with a particular emphasis on low level chemical warfare agents, oil fires, multiple vaccines, desert sand (Al-Eskan disease), botulism, Aspergillus flavus, Mycoplasma, aflatoxins, and others, contributing to the broad scope of clinical manifestations. Among several hundred thousand veterans deployed in the Operation Desert Storm, 15-20% have reported sick and about 25,000 died. Depleted uranium (DU), a low-level radioactive waste product of the enrichment of natural uranium with U-235 for the reactor fuel or nuclear weapons, has been considered a possible causative agent in the genesis of Gulf War Syndrome. It was used in the Gulf and Balkan wars as an armor-penetrating ammunition. In the operation Desert Storm, over 350 metric tons of DU was used, with an estimate of 3-6 million grams released in the atmosphere. Internal contamination with inhaled DU has been demonstrated by the elevated excretion of uranium isotopes in the urine of the exposed veterans 10 years after the Gulf war and causes concern because of its chemical and radiological toxicity and mutagenic and carcinogenic properties. Polarized views of different interest groups maintain an area of sustained controversy more in the environment of the public media than in the scientific community, partly for the reason of being less than sufficiently addressed by a meaningful objective interdisciplinary research.

Functional composition of Chaetodon butterflyfishes at a peripheral and extreme coral reef location, the Persian Gulf

KAUST Repository

Pratchett, Morgan S.; Hoey, Andrew; Feary, David A.; Bauman, Andrew G.; Burt, John A.; Riegl, Bernhard M.

2013-01-01

composition of butterflyfishes in the Persian Gulf, Musandam Peninsula, and Gulf of Oman. Only five species of butterflyfishes were recorded during this study, and mostly just in the Gulf of Oman. Unlike most locations in the Indo-Pacific where butterflyfish

Gulf of Mexico Ecosystem Status Report

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Gulf of Mexico is one of the most ecologically and economically valuable marine ecosystems in the world and is affected by a variety of natural and anthropogenic...

The reproduction of lake trout in southern Lake Superior

Science.gov (United States)

Eschmeyer, Paul H.

1955-01-01

The principal spawning grounds of lake trout (Salvelinus namaycush namaycush) in United States waters of southern Lake Superior are on rocky shoals at depths of less than 20 fathoms. Most spawning occurs in October and early November. Of the mature fish collected on or near the spawning grounds, 60 to 69 percent were males. Among mature fish the average length of females was greater than that of males; few males less than 24 inches or females less than 26 inches in total length were caught. Recoveries of lake trout tagged on the spawning grounds showed that some males remained in the immediate area for a period of several weeks during the spawning season. Marked fish showed a tendency to return during later years to spawning grounds on which they had been tagged, even though many of them ranged long distances between spawning seasons.

Treating Gulf War Illness with Novel Anti-Inflammatories: A Screening of Botantical Microglia Modulators