U.S. Geological Survey Toxic Substances Hydrology Program--Proceedings of the Technical Meeting Charleston South Carolina March 8-12, 1999--Volume 2 of 3--Contamination of Hydrologic Systems and Related Ecosystems, Water-Resources Investigations Report 99-4018B

Biomonitoring of Environmental Status and Trends (BEST) Program: Contaminants and Related Effects in Fish from the Mississippi, Columbia, and Rio Grande Basins

By C.J. Schmitt, T.M Bartish, V.S. Blazer, T.S. Gross, D.E. Tillitt, W.L. Bryant, and L.R. DeWeese

This report is available in pdf format: Schmitt.pdf

ABSTRACT

The Biomonitoring of Environmental Status and Trends (BEST) Program was initiated, in part, as a revision and expansion of the National Contaminant Biomonitoring Program (NCBP). One aspect of the BEST program focuses on monitoring contaminants and effects across broad geographic areas. This approach is currently being tested in the Mississippi, Columbia, and Rio Grande basins. The overall objectives of this project are to describe the occurrence and distribution of contaminants and their effects on fish in the three basins; to quantitatively evaluate the performance of aquatic methods used by the BEST program; and to evaluate potential collaborations with the National Stream Quality Accounting Network (NASQAN-II) and the National Water Quality Assessment (NAWQA) programs of the USGS-Water Resources Division. Fish were collected from 46 sites in the Mississippi River basin (1995); 16 sites in the Columbia River basin (1997); 10 sites in the Rio Grande basin (1997); and from a reference site in West Virginia. Sites were located at the historic NCBP fish monitoring stations in all three basins; at NASQAN-II water quality sampling sites in the Columbia and Rio Grande basins; and at NAWQA sites in the Mississippi Embayment and Eastern Iowa Basins study units within the Mississippi River basin. The primary species targeted at each site were common carp (Cyprinus carpio) and largemouth bass (Micropterus salmoides); other species, mostly other black basses (Micropterus spp.), percids (Stizostedion spp.), salmonids, suckers (Catostomidae), and catfish (Ictaluridae) were collected as alternates, depending on habitat and location. Individual fish (about 40 per station) were analyzed for reproductive biomarkers (vitellogenin and sex steroid hormones), histopathological alterations, macrophage aggregates, EROD activity, lysozyme activity, and general fish health measures (organosomatic and ponderal indices, observations of grossly visible lesions, deformities, and parasites). Organochlorine (pesticides and total PCB's) and elemental (heavy metals and metalloids) contaminant analyses and the H4IIE bioassay for dioxin-like activity were performed on fish samples composited by species and sex. In the Mississippi basin, DDT (mostly as p,p'-DDE) residues in fish remained sufficiently high in the southern parts of the watershed to represent a hazard to sensitive species of fish-eating birds. Toxaphene residues also remained evident. The combined results of organochlorine chemical, H4IIE bioassay, and biomarker analyses also indicated the presence of other organic contaminants in the lower Mississippi valley. Cyclodiene pesticides (dieldrin, endrin, and chlordane) were present in many agricultural areas, especially in the Corn Belt. Concentrations of these pesticides were also elevated at Memphis, Tennessee, where there is a point-source. Selenium concentrations were sufficiently high to constitute a hazard to piscivorous fishes and wildlife in the upper Arkansas River, where levels have been increasing for approximately 10 years. As expected, mercury concentrations were higher in the predator species than in bottom fish. The occurrence of vitellogenin in plasma and of ovarian cells in the testes of male fish from several sites, along with abnormal ratios of sex steroids, suggest that fish from some sites are exposed to endocrine-modulating substances.