Spencer A. Peterson

Selenium and mercury interactions with emphasis on fish tissue.

This review addresses the effects of mercury (Hg) in fish as it relates to the health of the fish themselves as well as potential risks of toxicity in wildlife and humans that consume fish. In particular, it addresses selenium (Se) as a bioindicator of susceptibility to harmful effects of Hg exposures and evaluates how Se moderates the toxic effects of Hg in a variety of test animals, emphasizing the importance of these potential effects in fish. A major conclusion of this review is that Hg toxicity risks to animal life cannot be accurately assessed without considering the moderating effects of Se. Therefore, Se:Hg molar ratios and their mathematical inverse are important factors that need to be considered when assessing risks from Hg exposures because exposures are related directly to toxicity outcome. In addition, actual measurement of both beneficial nutrients (e.g., Se, omega-3 fatty acids) and contaminants (e.g., Hg, polychlorinated biphenyls [PCB]) in fish tissue, rather than gross associations betw...

Indicators of Ecological Stress and Their Extent in the Population of Northeastern Lakes: A Regional-Scale Assessment

Article reporting findings from the Environmental Protection Agency (EPA)s Environmental Monitoring and Assessment Program (EMAP) conducted on a sample of lakes in the Northeastern United States from 1991 to 1996.

A comparison of impoundments and natural drainage lakes in the Northeast USA

We classified 235 randomly selected lentic waterbodies (>1 ha) in the Northeast USA as human created, or natural. We compared geographic extent and distribution, morphology and hydrology, trophic state, and fish assemblage metrics of impoundments and natural drainage lakes. We estimated that 46% of the 10 608 (±1695; 95% CI) lentic waterbodies in the region were impoundments or quarries; 68% of Uplands lakes and 26% of Lowlands lakes were natural. Impoundments were smaller, shallower, had shorter water residence times, and were in watersheds with greater human activity than were natural drainage lakes. More than half (55%) of Lowlands impoundments were eutrophic, accounting for 67% of eutrophic or hypereutrophic lentic waterbodies in the Northeast. An estimated 90% of eutrophic lakes and impoundments were <23 ha. Impoundments had greater proportions of fish species and individuals tolerant of human disturbance, and greater proportions of non-native species and individuals than did natural drainage lakes. We discuss some management implications of the differences between impoundments and natural drainage lakes.

Regional Lake Trophic Patterns in the Northeastern United States: Three Approaches

N = 11,076). Results were compared to a large, nonrandomly sampled data set for the same area compiled by Rohm and others and contrasted with lake trophic state information published in the National Water Quality Inventory: 1994 Report to Congress [305(b) report. Lakes across the entire Northeast were identified by EMAP data as 37.9% (±8.4%) oligotrophic, 40.1% (±9.7%) mesotrophic, 12.6% (±7.9%) eutrophic, and 9.3% (±6.3%) hypereutrophic. Lakes in the ADI and NEU generally are at a low, nearly identical trophic state (96% oligotrophic/mesotrophic), while those in the CLP are much richer (45% eutrophic). EMAP results are similar to results of the Rohm data set across the entire region. In the CLP, however, EMAP identified approximately 45% of the lakes as eutrophic/hypereutrophic, while the Rohm data set identified only 21% in these categories. Across the entire Northeast, the 305(b) report identified a much higher proportion (32.2%) of lakes in eutrophic condition and a much smaller proportion (19.8%) in oligotrophic condition than did the EMAP survey data (12.5% ± 7.9% and 37.9% ± 8.5%, respectively). Probability sampling has several advantages over nonrandom sampling when regional resource condition assessment is the goal.

Toxicological Assessment of Hazardous Waste Samples Extracted with Deionized Water or Sodium Acetate (TCLP) Leaching Media

Sodium acetate and deionized water elutriates prepared from municipal and industrial waste products, and the sodium acetate leaching media per se, recommended by the EPA for the Toxicity Characteristic Leaching Procedure (TCLP), were bioassayed for their toxicity potential. The toxicity bioassay organisms included: algae, Selenastrum capricornutum; macroinvertebrates, Daphnia magna; lettuce seed root elongation, Lactuca sativa L.; and, bacteria (Microtox), Photobacterium phosphoreum. The pH 5.0 sodium acetate leaching media was highly toxic to each of the test organisms. Adjustment of the pH to 7.0 decreased toxicity approximately 2.5-fold for algae and lettuce, and 6-fold for D. magna. This reduction, while statistically significant, did not change the toxicity classification of the sodium acetate leaching media. Photobacterium phosphoreum was un-affected by pH 7 sodium acetate leaching media after 30-minutes exposure. Toxicity of the industrial waste TCLP elutriates to D. magna and S. capricornutum was similar to that obtained in the elutriates prepared with deionized water. The response of D. magna to the TCLP elutriates from sewage sludge (POTW #2), municipal ash #1 and #2, paint sludge #2, Midco volatile soil, and First Chemical Corp. indicated that these samples contained acetate soluble contaminants which were more toxic than the sodium acetate itself. Bioassays detected toxicity in either TCLP or deionized water eluted samples. Toxicity of water eluted samples can be attributed to materials leached from the waste. Toxicity of the TCLP eluted samples is problematic due to uncertainty of the amount of toxicity attributable to the leaching media itself vs. the materials leached from the wastes.

THE U.S. ENVIRONMENTAL PROTECTION AGENCY'S CLEAN LAKES PROGRAM: 1975–1985

ABSTRACT The EPA Clean Lakes Program was initiated in 1975 to protect publicly-owned freshwater lakes under Section 314 of the Clean Water Act. A review of the first decade of the Program by Battelle Memorial Institute highlights the accomplishments of the Clean Lakes Program, the results of federally funded projects and recommendations for the future. From 1975 to 1985, EPA funded 313 Clean Lakes studies and projects totaling

How might selenium moderate the toxic effects of mercury in stream fish of the western U.S.

93 million in federal dollars. Forty-seven states and Puerto Rico participated. The majority of funds (87 percent) was awarded to lake restoration projects. The remainder was used for lake classification studies and diagnostic feasibility studies. Public concern about lake eutrophication was the most significant factor in prompting action that resulted in restoration. The Program has improved water quality nationwide; examples of public and economic benefits are cited. In addition, the Clean Lakes Program has contributed to the science of lake restoration through a better public an...