Stormwater runoff in a coastal urban area (San Diego County, CA) produced significant toxicity to early life stages of medaka (Oryzias latipes) and Menidia (M. beryllina). Exposure of embryos to lower concentrations (5 to 25%) increased the incidence of abnormal swim bladder inflation and other teratogenic responses, whereas higher concentrations resulted in mortality or failure to hatch. Comparisons of EC50s for mortality and failure to hatch with concentrations of individual chemical pollutants (including Cd, Cr, Cu, Pb, Ni, and Zn) revealed low correlations; however, the correlation with total metals was high (-0.84) and corresponded with sample exceedences of Water Quality Criteria (WQC) for Cd, Cu, Pb, and Zn. This strong association between developmental toxicity and toxic metal content of storm water compared favorably with developmental anomalies reported in other studies. Analytical chemistry data for pesticides that may have been in these samples were limited to selected pesticides found usually below detection limits. Greater toxicity of the watershed effluents sampled was generally associated with more developed land surface and less open space. Both medaka and Menidia were found to be useful for studying effects of stormwater on embryonic and early larval development. http://link.springer-ny. com/link/service/journals/00244/bibs/37n2p227.html
It has been hypothesized that a principal route of human exposure to polybrominated diphenyl ethers (PBDEs), used as flame retardants, is through fish consumption. Between 1999 and 2005 PBDE-47, -99, -100, -153, and -154 were analyzed in 3797 biological samples of 33 species of the Hudson River, New York. Approximately 98.4% of the samples contained PBDEs between 0.5 and 37 169 ng g(-1) lipid, with a median concentration of 772 ng g(-1) lipid. Yearly median sigmaPBDE concentrations fluctuated. Samples from river miles 112 and 153 contained higher sigmaPBDEs than those from other locations of the river. The 7-year median sigmaPBDE concentrations were the highest in large carnivorous fishes and the lowest in insects. The median abundance of congener PBDE-47 decreased from 80% to 63% with decreasing levels of sigmaPBDEs in the samples, while an increase from 2% to 23% was observed for PBDE-99. The median abundance of other congeners did not change with concentrations of sigmaPBDEs. Positive-, negative-, and no-correlation between sigmaPBDE concentrations and fish weight were observed for different species and for the same species from different locations of the river. The sources of PBDE contamination, diet, metabolic activity, and sediment chemistry might affect the levels of PBDEs in a fish.
Atmospheric emissions of mercury in the US are being reduced, but worldwide mercury emissions remain high. Mercury is also being removed from many consumer items. Changes over time in mercury concentrations in fish remain important to resource managers and the general public. There is hope that mercury concentrations in fish will decline, and the number of fish consumption advisories due to mercury will decrease. We compared mercury concentrations in yellow perch (Perca flavescens) from a group of Adirondack lakes with data collected 12-17 years earlier and found variable responses among lakes. We observed an average decline of 14% in yellow perch mercury concentrations over the past 15 years.
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