			Home About us Contact

Great Salt Lake (great + salt_lake)

Distribution by Scientific Domains

Life Sciences	100%

Selected Abstracts

Concentrations of selenium and mercury in eared grebes (Podiceps nigricollis) from Utah's great Salt Lake, USA

ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 6 2009
Michael R. Conover
Abstract We examined selenium and mercury concentrations in eared grebes (Podiceps nigricollis) that spent the fall of 2006 on the Great Salt Lake (UT, USA), where their diet consisted mainly of brine shrimp (Artemia franciscana). Selenium concentrations in livers varied based on when the grebes were collected (lower in September [mean ± standard error, 9.4 ± 0.7 ,g/g dry wt] than in November [14.5 ± 1.4 ,g/g]), on where the birds were collected on the Great Salt Lake (Antelope Island, 8.6 ± 0.5 ,g/g; Stansbury Island, 15.2 ± 1.4 ,g/g), and on the grebe's age (juveniles, 8.5 ± 1.5 ,g/g; adults, 15.8 ± 1.3 ,g/g), but not by sex. Selenium concentrations in blood differed only by collection site (Antelope Island, 16.8 ± 2.3 ,g/g; Stansbury Island, 25.4 ± 3.0 ,g/g). Mercury concentration in the blood of grebes varied by when the grebes were collected (September, 5.6 ± 0.5 ,g/g; November, 8.4 ± 1.2 ,g/g), where the birds were collected (Antelope Island, 4.3 ± 0.5 ,g/g; Stansbury Island, 10.1 ± 2.6 ,g/g), and the grebe's age (juveniles, 5.5 ± 0.8 ,g/g; adults, 8.4 ± 1.0 ,g/g), but not by sex. Selenium concentrations in blood were correlated with selenium concentrations in the liver and with mercury concentrations in both blood and liver. Body mass of grebes increased dramatically from September (381 ± 14 g wet wt) to November (591 ± 11 g). Body, liver, and spleen mass either were not correlated with selenium or mercury concentrations or the relationship was positive. These results suggest that high mercury and selenium levels were not preventing grebes from increasing or maintaining mass. [source]

Selenium and mercury concentrations in California gulls breeding on the Great Salt Lake, Utah, USA

ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 2 2009
Michael R. Conover
Abstract We examined selenium (Se) and mercury (Hg) concentrations in adult California gulls (Larus californicus) nesting on the Great Salt Lake, Utah, USA, during 2006 and 2007. During 2006, the mean Se concentration (± standard error) was 18.1 ± 1.5 ,g/g in blood on a dry-weight basis and 8.1 ± 0.4 ,g/g in liver. During 2007, Se concentrations were 15.7 ± 1.5 ,g/g in blood and 8.3 ± 0.4 ,g/g in liver; Hg concentrations were 2.4 ± 0.3 ,g/g in blood and 4.1 ± 0.5 ,g/g in liver. Gulls collected from a freshwater colony located within the watershed of the Great Salt Lake had similar levels of Se in the blood and liver as gulls collected on the Great Salt Lake but lower Hg concentrations. Body mass of adult gulls was not correlated with Se or Hg concentrations in their blood or liver. Selenium concentration in California gull eggs collected during 2006 was 3.0 ± 0.10 ,g/g. Of 72 eggs randomly collected from Great Salt Lake colonies, only one was infertile, and none of the embryos exhibited signs of malposition or deformities. We examined 100 newly hatched California gull chicks from Great Salt Lake colonies for teratogenesis; all chicks appeared normal. Hence, the elevated Se and Hg concentrations in adult gulls nesting on the Great Salt Lake did not appear to impair gulls' health or reproductive ability. [source]

Diversity of sulfate-reducing bacteria from an extreme hypersaline sediment, Great Salt Lake (Utah)

FEMS MICROBIOLOGY ECOLOGY, Issue 2 2007
Kasper Urup Kjeldsen
Abstract The diversity of sulfate-reducing bacteria (SRB) inhabiting the extreme hypersaline sediment (270 g L,1 NaCl) of the northern arm of Great Salt Lake was studied by integrating cultivation and genotypic identification approaches involving PCR-based retrieval of 16S rRNA and dsrAB genes, the latter encoding major subunits of dissimilatory (bi) sulfite reductase. The majority (85%) of dsrAB sequences retrieved directly from the sediment formed a lineage of high (micro) diversity affiliated with the genus Desulfohalobium, while others represented novel lineages within the families Desulfohalobiaceae and Desulfobacteraceae or among Gram-positive SRB. Using the same sediment, SRB enrichment cultures were established in parallel at 100 and at 190 g L,1 NaCl using different electron donors. After 5,6 transfers, dsrAB and 16S rRNA gene-based profiling of these enrichment cultures recovered a SRB community composition congruent with the cultivation-independent profiling of the sediment. Pure culture representatives of the predominant Desulfohalobium -related lineage and of one of the Desulfobacteraceae -affilated lineages were successfully obtained. The growth performance of these isolates and of the enrichment cultures suggests that the sediment SRB community of the northern arm of Great Salt Lake consists of moderate halophiles, which are salt-stressed at the in situ salinity of 27%. [source]