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Results 201 - 250 of 842
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Elser James J - - 2010
Here, we present data that for the first time suggests that the effects of atmospheric nitrogen (N) deposition on nutrient limitation extend into the food web. We used a novel and sensitive assay for an enzyme that is over-expressed in animals growing under dietary phosphorus (P) deficiency (alkaline phosphatase activity, ...
Epanchin Peter N - - 2010
Adjacent food webs may be linked by cross-boundary subsidies: more-productive donor systems can subsidize consumers in less-productive neighboring recipient systems. Introduced species are known to have direct effects on organisms within invaded communities. However, few studies have addressed the indirect effects of nonnative species in donor systems on organisms in ...
Meneely Julie - - 2010
A rapid screening assay (9 min/sample) has been developed and validated for the detection of deoxynivalenol in durum wheat, wheat products, and maize-based baby foods using an SPR biosensor. Through a single laboratory validation, the limits of detection (LOD) for wheat, wheat-based breakfast cereal, and maize-based baby food were 57, ...
Molina Carlos Israel - - 2010
We have evaluated the mercury and methylmercury transfers to and within the macroinvertebrate communities of a floodplain lake of the Beni River basin, Bolivia, during three hydrological seasons and in two habitats (open water and vegetation belt). Using the stable isotopes delta(13)C and delta(15)N, six trophic chains were identified during ...
Gusmão Luciana C - - 2010
Sea anemones in genera Adamsia, Calliactis and Paracalliactis (family Hormathiidae) engage in a mutualistic symbiosis with hermit crabs in which the anemone gains substrate and food in exchange for defending the crab. Some of the sea anemones also expand the living space of the crab by producing a carcinoecium, a ...
Stoll S - - 2010
Total length, body mass and gut content mass of young-of-the-year (YOY) perch Perca fluviatilis, dace Leuciscus leuciscus and bleak Alburnus alburnus were recorded over the summer of 2006 at three littoral sites at Upper Lake Constance. In P. fluviatilis and L. leuciscus, gut content mass correlated positively with wave-induced energy ...
Swanson Heidi K - - 2010
Single-spawning (semelparous) anadromous fishes are known to transport contaminants from marine to freshwater habitats, but little research has been conducted on contaminant biotransport by multiple-spawning (iteroparous) anadromous fishes. We examined the effect of iteroparous, anadromous Arctic charr (Salvelinus alpinus) on mercury concentrations ([Hg]) in freshwater biota and compared [Hg] between ...
Elzupir Amin O - - 2010
Vegetable oil (n = 81) for human consumption from Khartoum State in Sudan were analyzed for aflatoxins (AFs), using high-performance liquid chromatography (HPLC) with fluorescence detection following extraction with methanol:water (80:20) and clean-up using petroleum ether. Sampling included sesame oil (n = 14), peanut oil (n = 21), and sunflower oil (n = 19) purchased from retail shops, ...
Gantner Nikolaus - - 2010
Among-lake variation in mercury (Hg) concentrations in landlocked Arctic char was examined in 27 char populations from remote lakes across the Canadian Arctic. A total of 520 landlocked Arctic char were collected from 27 lakes, as well as sediments and surface water from a subset of lakes in 1999, 2002, ...
Gantner Nikolaus - - 2010
Concentrations of mercury (Hg) have increased slowly in landlocked Arctic char over a 10- to 15-year period in the Arctic. Fluxes of Hg to sediments also show increases in most Arctic lakes. Correlation of Hg with trophic level (TL) was used to investigate and compare biomagnification of Hg in food ...
Almeida M P - - 2010
The stomach contents of 137 examples of Potamotrygon motoro caught in 3 locations (Muaná, Afuá and Lake Arari) on Marajó Island were analysed. The values of the Index of Relative Importance (IRI) and its respective percentage (%IRI) were calculated. The level of repletion 1 (1/4 full) was the most representative ...
Hern?ndez J C - - 2010
We assessed the influence of rock cavities, or pits, on the growth dynamics and behavior of the purple sea urchin, Strongylocentrotus purpuratus. In a paired-designed, laboratory experiment, sea urchins were assigned to sandstone blocks that were either 'Flat' or had a 'Pit' drilled into the center. At the start, both ...
Ings Nicola L - - 2010
Sedentary species face a trade-off between the benefits of exploiting food close to their homes and the cost of defending it. In aquatic systems, it has been suggested that some sedentary grazers can increase the range of circumstances under which they are at an advantage over mobile grazers by enhancing ...
Ogurlu Idris - - 2010
This study has been conducted between years 2002-2008 in nearby Egirdir lake, which is acknowledged to be amongst the biggest fresh water lakes in Turkey. Within the scope of this study observations have been made on one of the cat species common in Turkey, Jungle Cat Felis chaus, its biology ...
Senko Jesse - - 2009
Sea turtles have historically been an important food resource for many coastal inhabitants of Mexico. Today, the consumption of sea turtle meat and eggs continues in northwestern Mexico despite well-documented legal protection and market conditions providing easier access to other more reliable protein sources. Although there is growing evidence that ...
Flint M - - 2010
Chelonid corneal fibropapillomatosis has not previously been recorded in Australian waters. During 2008, 724 green sea turtles (Chelonia mydas) were examined in Queensland, Australia at two sites, Moreton Bay (n=155) and Shoalwater Bay (n=569), during annual monitoring. In the same calendar year, 63 turtles were submitted from various sites in ...
Garmendia Joxe Mikel - - 2009
Laboratory experiments were carried out over two different periods, with the aim of investigating and utilizing the induction to gonadal maturation of the sea urchin Paracentrotus lividus. The final objective was to obtain viable gametes outside the period of natural spawning in the environment; which would allow the utilization of ...
Sarkar S - - 2009
Deep-sea benthic foraminifera, planktic foraminifer Globigerina bulloides and pteropods have been quantitatively analysed in 451 samples from Ocean Drilling Program (ODP) Hole 716A, to understand both surface and deep-sea palaeoceanographic changes in the equatorial Indian Ocean basin during the late Quaternary (approximately 444-151 Kyrs). Benthic foraminifera were analysed from >125 ...
Kuo Yin-Ming - - 2010
Polybrominated diphenyl ethers are hydrophobic chemicals and can biomagnify in food chains. Little is known about the biomagnification of PBDEs in the Lake Michigan food web. Plankton, Diporeia, lake whitefish, lake trout, and Chinook salmon were collected from Lake Michigan in 2006 between April and August. Fish liver and muscle ...
Horppila J - - 2009
The diet and growth of two cyprinids, roach Rutilus rutilus and rudd Scardinius erythrophthalmus, in the clay-turbid Kirkkojärvi basin in Lake Hiidenvesi (Finland) were studied. Young R. rutilus fed mainly on detritus, molluscs, chironomids and zooplankton, while older individuals consumed mostly detritus, molluscs and filamentous algae. In the food of ...
Hu Guocheng - - 2010
Organochlorine pesticides (OCPs), such as hexachlorocyclohexane (HCH) and dichlorodiphenyltrichloroethane (DDT), are ubiquitous anthropogenic environmental contaminants. They are persistent, broad-spectrum toxicants that accumulate in the food web with potential risks to the ecosystem and human health. HCHs were the predominant contaminants in Baiyangdian Lake, North China. Concentrations of HCHs and DDTs ...
Schoch Rainer R - - 2009
The evolution of life cycles forms the subject of numerous studies on extant organisms, but is rarely documented in the fossil record. Here, I analyze patterns of development in time-averaged samples of late Carboniferous and early Permian amphibians, and compare them to paleoecological patterns derived from the same deposits located ...
Dörner H - - 2009
The feeding habits of the European eel Anguilla anguilla (>300 mm total length, L(T)) were compared in two lakes of different environmental state: Lake Grosser Vätersee (LGV), Germany (clear water, mesotrophic and submerged macrophytes), and Lake Vallum (LV), Denmark (turbid, eutrophic and no submerged macrophytes). The density of macrozoobenthos was ...
Freyre L R - - 2009
The study object was an Odontesthes bonariensis (Valenciennes, 1835) population of a characteristically shallow lake from the pampasic region. Over one year, zooplankton and fish samples were collected monthly. As a function of time and gender, several indices were investigated (relative weight, mesentery fat index, gonadosomatic index, hepatosomatic index and ...
Ismail Nargis - - 2009
Concentrations of non-polybrominated diphenyl ether (PBDE) brominated (hexabromocyclododecane [HBCD], 1,2-bis[2,4,6-tribromophenoxy]ethane [BTBPE], and pentabromoethylbenzene [PEB]) and chlorinated (Dechlorane Plus [DP] as well as short- and medium-chain chlorinated paraffins [SCCP and MCCP, respectively]) flame retardants were evaluated in archived Lake Ontario, Canada, lake trout (Salvelinus namaycush) samples collected between 1979 and 2004. ...
Coma Rafel - - 2009
Summer conditions in the Mediterranean Sea are characterized by high temperatures and low food availability. This leads to "summer dormancy" in many benthic suspension feeders due to energetic constraints. Analysis of the most recent 33-year temperature time series demonstrated enhanced stratification due to global warming, which produced a approximately 40% ...
Vinni M - - 2009
Growth of pikeperch Sander lucioperca in the eutrophic and clay-turbid Lake Sahajärvi, Southern Finland, was extremely slow in comparison with other lakes at similar latitudes. The most important food item in July was phantom midge larvae Chaoborus flavicans for all sizes of S. lucioperca (239-423 mm total length L(T)), while ...
DOI, Hideyuki
Lake Katanuma is a colcanic, strongly acidic lake (average pH of 2.2), located in Miyagi prefecture, Japan. Only a few spieccies are found in Katanuma; Chironomus acerbiphis larvae as benthic invertebrate, Pinnularia baunii as benthic diatom, and Chlamydomonas acidophila as phytoplnkton. We tried analyzing seasonal changes of carbon and nitrogen ...
Hille, Kelly Amber
Epilithic biofilms were monitored for potential impacts of an experimental rainbow trout aquaculture operation at the Experimental Lakes Area in northwestern Ontario, Canada. Metabolic and particulate samples were collected from the middle littoral zone of the experimental and reference lakes before and during the aquaculture operation. Phosphorus stocks in the ...
Ivanov Alexei V - - 2009
As known from inland sedimentary records, boreholes, and geophysical data, the initiation of the Baikal rift basins began as early as the Eocene. Dating of volcanic rocks on the rift shoulders indicates that volcanism started later, in the Early Miocene or probably in the Late Oligocene. Prominent tectonic uplift took ...
Salm Courtney R - - 2009
Seasonal changes in freshwater phytoplankton communities have been extensively studied, but key drivers of phytoplankton in saline lakes are currently not well understood. Comparative lake studies of 19 prairie saline lakes in the northern Great Plains (USA) were conducted in spring and summer of 2004, with data gathered for a ...
Naddafi Rahmat - - 2009
Elemental imbalances of carbon (C): nitrogen (N): phosphorus (P) ratios in food resources can constrain the growth of grazers owning to tight coupling between growth rate, RNA allocation and biomass P content in animals. Testing for stoichiometric constraints among invasive species is a novel challenge in invasion ecology to unravel ...
Robidoux Michael A MA School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada. - - 2009
This article is based on a study of traditional lifestyle practices in the Sandy Lake First Nation community in northwestern Ontario, considering some of the benefits and risks of reintroducing off-the-land food sources, specifically as they relate to the burbot (Lota lota L). This article concentrates, therefore, on four avenues ...
Skwarzec Bogdan - - 2009
The present study deals with the application of self-organizing maps (SOM) in order to model, classify and interpret seasonal and spatial variability of (210)Po, (238)U and (239+240)Pu levels in the Vistula river basin. The data set represents concentration values for 3 alpha emitters ((210)Po, (238)U and (239+240)Pu) measured in surface ...
Venier Marta - - 2008
The first estimates of atmospheric deposition of polychlorinated diphenyl ethers (PBDEs) into the Great Lakes are presented. Precipitation samples were collected monthly from 2005 to 2006 at five sites located in the Great Lakes region. Volume weighted mean concentrations of total PBDEs in precipitation ranged from 94 +/- 19 ng ...
Marshall Harold G - - 2009
Phytoplankton and water quality long term trends are presented from a 20-year monitoring program of Chesapeake Bay and several of its major tributaries. Increasing phytoplankton biomass and abundance are ongoing within this estuarine complex, with diatoms the dominant component, along with chlorophytes and cyanobacteria as sub-dominant contributors in the tidal ...
Olsen Anthony R - - 2009
The National Lake Fish Tissue Study (NLFTS) was the first survey of fish contamination in lakes and reservoirs in the 48 conterminous states based on a probability survey design. This study included the largest set (268) of persistent, bioaccumulative, and toxic (PBT) chemicals ever studied in predator and bottom-dwelling fish ...
Amer Ranya - - 2009
Optimized denaturing gradient gel electrophoresis (DGGE) fingerprinting and real-time PCR were performed to identify and quantify the potential hepatotoxic microcystin- and nodularin-producing cyanobacteria present in freshwater samples collected during different seasons at three different sites from the Nile River Delta. The combined use of molecular gene markers (targeting the aminotransferase ...
Warby Richard A F - - 2008
We surveyed 113 lakes in the northeastern U.S. in 2001 that had previously been sampled in 1986 to evaluate the effects of reductions in acidic deposition on the concentrations and speciation of aluminum (Al). We found ubiquitous decreases in the concentrations of total Al and inorganic monomeric aluminum (Ali) across ...
Venn A A - - 2008
The capacity of some corals and other cnidarians to form symbioses with multiple algae (Symbiodinium) is a candidate route by which these symbioses tolerate variable environmental conditions. On Bermuda, the coral reef dwelling anemone Condylactis gigantea bears Symbiodinium of clades A and B. At thermally variable inshore and nearshore sites, ...
Roth, A. R.
The objectives of the present survey of the upper waters of the South Fork of the Umpqua River were to: (1) develop practical and. scientifically sound stocking policies; (2) determine the need for stream and lake improvements; and (3) obtain facts to assist in the settlement of the controversy with ...
Girard Vincent - - 2008
Amber usually contains inclusions of terrestrial and rarely limnetic organisms that were embedded in the places were they lived in the amber forests. Therefore, it has been supposed that amber could not have preserved marine organisms. Here, we report the discovery amber-preserved marine microfossils. Diverse marine diatoms as well as ...
Cecala Rebecca K - - 2008
Increased water clarity associated with zebra mussel (Dreissena polymorpha) populations may favor benthic algal primary production in freshwater systems previously dominated by pelagic phytoplankton production. While zebra mussel-mediated water clarity effects on benthic primary production have been implicated in published reports, few production estimates are available. This study estimates benthic ...
Gupta, Anil K
Tropical climate is variable on astronomical time scale, driving changes in surface and deep-sea fauna during the Pliocene-Pleistocene. To understand these changes in the tropical Indian Ocean over the past 2.36 Myr, we quantitatively analyzed deep-sea benthic foraminifera and selected planktic foraminifera from >125 µm size fraction from Deep Sea ...
Galban, Evelyn
Avian Vacuolar Myelinopathy (AVM) is an emerging disease that is responsible for lesions of the CNS associated with morbidity and mortality of American coots (Fulica americana) and bald eagles (Haliaeetus leucocephalus) in the southeastern United States. The number of species and birds affected by AVM has been increasing since it ...
Njiru, M.
Nile tilapia, Oreochromis niloticus together with other tilapiines of Oreochromis leucosticus, Tilapia zillii and Sarotherodon melanopleudra (=T. rendalii) were introduced into Lake Victoria (Kenya) between 1951 and 1962 to boost the then declining fishery. Only O. niloticus was able to establish leading further to reduction in endemic tilapiines of Oreochromis ...
Rodas-Ortíz Juan Pablo - - 2008
Vitellogenin (Vtg), 17beta-estradiol (E2) and testosterone (T) were used as biomarkers of endocrine disruption in mature male nile tilapia (Oreochromis niloticus) from three lakes (Rio, Enmedio and Limon) in Chiapas, Mexico. Vitellogenesis induction was found in tilapias from Rio and Limon, moderately high E(2) levels in Rio and Limon tilapias, ...
Suffredini E - - 2008
AIMS: To investigate the presence of enteric viruses [hepatitis A (HAV) and norovirus (NoV)] in shellfish harvested from the deltaic area of the Po river in relation to environmental factors. METHODS AND RESULTS: Fortnightly sampling of shellfish was carried out in two lagoon areas (category B production areas) and one ...
Cloern James E - - 2008
Seasonal fluctuations of plant biomass and photosynthesis are key features of the Earth system because they drive variability of atmospheric CO(2), water and nutrient cycling, and food supply to consumers. There is no inventory of phytoplankton seasonal cycles in nearshore coastal ecosystems where forcings from ocean, land and atmosphere intersect. ...
Lizárraga-Partida M L - - 2009
The El Niño event of 1997/1998 provided an opportunity to carry out a field experiment in which the relationship of sea surface temperature and the association of Vibrio cholerae with marine plankton could be assessed in Mexican coastal and estuarine areas. Plankton samples were collected from May 1997 through June ...
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