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Smallmouth bass ( Micropterus dolomieui) populations in two of five reservoirs sampled in the southern Appalachian Mountains contained high percentages of individuals with lordosis, kyphosis, or scoliosis. Deformities of the vertebral column occurred in several year classes and varied with fish size; they were absent in small fish, present in 25-30% of the fish 241-300 mm long, and then decreased in occurrence with increased length. Because environmental contamination is often responsible for high occurrences of deformed fish, whole-body concentrations of contaminants, bone development characteristics, and blood plasma concentrations of calcium and phosphorus in normal and deformed fish were measured and compared the results with those for fish from reservoirs where no deformities were found. Vertebrae were significantly weaker and more elastic in deformed than in normal fish, but biochemical properties of vertebrae were similar among the groups tested. Concentrations of pesticides and metals were not elevated in deformed fish, and concentrations of calcium and phosphorus in blood plasma were similar in normal and deformed groups. Most environmental contaminants that have been shown to cause fish deformities could be discounted as causative agents on the basis of these results; however, the exact cause was not determined. Further attempts to diagnose the cause of the deformities were limited by the lack of background information on relationships among bone development processes, types of stresses that cause deformities, and types of bone tissue in fish. [ABSTRACT FROM AUTHOR]

Arsenic, Cd, Cu, Pb, Hg, and Zn were measured in sediments, biofilm,benthic macroinvertebrates, and fish from the Coeur d'Alene (CDA) River to characterize the pathway of metals transfer between these components. Metals enter the CDA Basin via tributaries where mining activities have occurred. In general, the ranking of food-web components from the greatest to smallest concentrations of metals was as follows:biofilm (the layer of abiotic and biotic material on rock surfaces) and sediments > invertebrates > whole fish. Elevated Pb was documented in invertebrates, and elevated Cd and Zn were documented in sediment and biofilm approximately 80 km downstream to the Spokane River. The accumulation of metals in invertebrates was dependent on functionalfeeding group and shredders-scrapers that feed on biofilm accumulated the largest concentrations of metals. Although the absolute concentrations of metals were the largest in biofilm and sediments, the metals have accumulated in fish approximately 50 km downstream from Kellogg, near the town of Harrison. While metals do not biomagnify betweentrophic levels, the metals in the CDA Basin are bioavailable and do biotransfer. Trout less than 100 mm long feed exclusively on small invertebrates, and small invertebrates accumulate greater concentrations of metals than large invertebrates. Therefore, early-lifestage fishmay be exposed to a larger dose of metals than adults. [ABSTRACT FROM AUTHOR]

We studied the ecological effects of mining-derived metals on riffle-dwelling benthic fishes at 16 sites in the Viburnum Trend lead-zinc mining district of southeast Missouri. Fish community attributes were compared to watershed features and to physical and chemical variables including metal concentrations in sediment pore water and fish. Ozark sculpin (Cottus hypselurus), rainbow darter (Etheostoma caeruleum), Ozark madtom (Noturus albater), and banded sculpin (Cottus carolinae) were the most abundant fishes collected. Species richness and density of riffle-dwelling benthic fishes were negatively correlated with metal concentrations in pore water and in fish. Sculpin densities were also negatively correlated with metal concentrations in pore water and in fish, but positively correlated with distance from mines and upstream watershed area. These findings indicate that metals associated with active lead-zinc mining adversely affect riffle-dwelling benthic fishes downstream of mining areas in the Viburnum Trend. Sculpins may be useful as a sentinel species for assessing mining-related impacts on fish communities.

The Viburnum Trend mining district in southeast Missouri, USA is one of the largest producers of lead-zinc ore in the world. Previous stream surveys found evidence of increased metal exposure and reduced population densities of crayfish immediately downstream of mining sites. We conducted an in-situ 28-d exposure to assess toxicity of mining-derived metals to the woodland crayfish (Orconectes hylas). Crayfish survival and biomass were significantly lower at mining sites than at reference and downstream sites. Metal concentrations in water, detritus, macroinvertebrates, fish, and crayfish were significantly higher at mining sites, and were negatively correlated with caged crayfish survival. These results support previous field and laboratory studies that showed mining-derived metals negatively affect O. hylas populations in streams draining the Viburnum Trend, and that in-situ toxicity testing was a valuable tool for assessing the impacts of mining on crayfish populations.

As an integral part of our continuing research in environmental quality assessment approaches, we have developed a variety of passive integrative sampling devices widely applicable for use in defining the presence and potential impacts of a broad array of contaminants. The semipermeable membrane device has gained widespread use for sampling hydrophobic chemicals from water and air, the polar organic chemical integrative sampler is applicable for sequestering waterborne hydrophilic organic chemicals, the stabilized liquid membrane device is used to integratively sample waterborne ionic metals, and the passive integrative mercury sampler is applicable for sampling vapor phase or dissolved neutral mercury species. This suite of integrative samplers forms the basis for a new passive sampling approach for assessing the presence and potential toxicological significance of a broad spectrum of environmental contaminants. In a proof-of-concept study, three of our four passive integrative samplers were used to assess the presence of a wide variety of contaminants in the waters of a constructed wetland, and to determine the effectiveness of the constructed wetland in removing contaminants. The wetland is used for final polishing of secondary-treatment municipal wastewater and the effluent is used as a source of water for a state wildlife area. Numerous contaminants, including organochlorine pesticides, polycyclic aromatic hydrocarbons, organophosphate pesticides, and pharmaceutical chemicals (e.g., ibuprofen, oxindole, etc.) were detected in the wastewater. Herein we summarize the results of the analysis of the field-deployed samplers and demonstrate the utility of this holistic approach.

The toxicity of an acid mine drainage (AMD) mixing zone was investigated by placing bluegill (Lepomis macrochirus) at the confluence of a stream contaminated by AMD and a stream having neutral pH. A mixing channel receiving water from both streams was assembled in the field, during July and October 1996, to determine the toxicity of freshly mixed and aged water (2.9-7.5 min). The AMD stream had elevated concentrations of Al and Fe, which precipitated upon mixing, and of Mn, which did not precipitate in the mixing zone. Fish exposed to freshly mixed water had higher mortality than fish exposed to water after aging. Precipitating Al, but not Fe, accumulated on the gills of bluegill, and accumulation was more rapid early during the mixing process than after aging. Fish exposed for 3.5 h to freshly mixed water had hypertrophy and hyperplasia of gill filament and lamellar epithelial cells. Similar lesions were observed after 6.0 h in fish exposed to water aged after mixing. Results demonstrated that Al was the predominant metal accumulating on the gills of fish in this AMD mixing zone, and that mixing zones can be more toxic than AMD streams in equilibrium.

Boron (B), molybdenum (Mo), and selenium (Se) were measured in water, sediment, particulate organic detritus, and in various biota--filamentous algae, net plankton, macro-invertebrates, and fishes--to determine if concentrations were elevated from exposure to agricultural subsurface (tile) drainage during the spring and fall 1987, in the San Joaquin River, California. Concentrations of B and Se, but not Mo, were higher in most samples from reaches receiving tile drainage than in samples from reaches receiving no tile drainage. Maximum concentrations of Se in water (0.025 microgram/mL), sediment (3.0 micrograms/g), invertebrates (14 micrograms/g), and fishes (17 micrograms/g) measured during this study exceeded concentrations that are detrimental to sensitive warmwater fishes. Toxic threshold concentrations of B and Mo in fishes and their foods have not been identified. Boron and Mo were not biomagnified in the aquatic food chain, because concentrations of these two elements were usually higher in filamentous algae and detritus than in invertebrates and fishes. Concentrations of Se were lower in filamentous algae than in invertebrates and fishes; however, concentrations of Se in or on detritus were similar to or higher than in invertebrates and fishes. These observations suggest that high concentrations of Se accumulated in invertebrates and fishes through food-chain transfer from Se-enriched detritus rather than from filamentous algae.

The present paper describes a simple modification of a recently reported decomposition method for determination of selenium in biological tissue by hydride generation atomic absorption. The modified method yielded slightly higher selenium recoveries (3-4%) for selected reference tissues and fish tissue spiked with selenomethionine. Radiotracer experiments indicated that the addition of a small volume of hydrochloric acid to the wet digestate mixture reduced slight losses of selenium as the sample initially went to dryness before ashing. With the modified method, selenium spiked as selenomethionine behaved more like the selenium in reference tissues than did the inorganic spike forms when this digestion modification was used.

From late 1984 to early 1985, the U.S. Fish and Wildlife Service collected a total of 315 composite samples of whole fish from 109 stations nationwide, which were analyzed for arsenic, cadmium, copper, lead, mercury, selenium, and zinc. Geometric mean, maximum, and 85th percentile concentrations (μg/g wet weight) for 1984 samples were as follows: arsenic-0.14, 1.5, 0.27; cadmium-0.03, 0.22, 0.05; copper-0.65, 23.1, 1.0; mercury-0.10, 0.37, 0.17; lead-0.11, 4.88, 0.22; selenium-0.42, 2.30, 0.73; and zinc-21.7, 118.4, 34.2. The mean concentrations of selenium and lead were significantly lower than in the previous NCBP collection (1980-81). Mean concentrations of arsenic and cadmium also declined significantly between 1976, when elemental contaminants in fish were first measured in the NCBP, and 1984. Of greatest significance, lead concentrations declined steadily from 1976 to 1984, suggesting that regulatory measures have successfully reduced the influx of lead to the aquatic environment.

A combined wet chemical and dry ash digestion and use of a continuous-flow hydride generator coupled with a flame-heated quartz cell enabled the simple, precise, and highly automated atomic absorption determination of arsenic and selenium in tissues of whole fish. Percent relative standard deviation averaged 4% for each element; method detection limits (micrograms/g dry wt) were about 0.06 for arsenic and 0.04 for selenium. Digestion of samples proceeded with little operator attention and without perchloric acid. Analysis for arsenic as As(V) simplified sample preparation but care had to be exercised to avoid interferences from high concentrations of selenium.