Geology topics

Gail M. Dethloff

Publications and source records attributed to Gail M. Dethloff.

4 recordsLinked to original sources

USGS2005

Biomonitoring of Environmental Status and Trends (BEST) Program: Environmental contaminants and their effects on fish in the Columbia River Basin

This project examined and analyzed 560 fish representing eight species from 16 sites in the Columbia River Basin (CRB) from September 1997 to April 1998. Ten of the 16 sampling locations were historical National Contaminant Biomonitoring Program (NCBP) sites where organochlorine and elemental contaminants in fish had been monitored from 1969 through 1986. Five sites were co-located at U.S. Geological Survey (USGS)-National Stream Quality Accounting Network (NASQAN) stations at which water quality is monitored. The sampling location at Marine Park in Vancouver, Washington did not correspond to either of the established monitoring programs. Eight of the sampling locations were located on the Columbia River; three were on the Snake River; two were on the Willamette River, and one site was on each of the Yakima, Salmon and Flathead Rivers. Common carp ( Cyprinus carpio ), black basses ( Micropterus sp. ), and largescale sucker ( Catostomus macrocheilus ) together accounted for 80% of the fish sampled during the study. Fish were weighed and measured then field-examined for external and internal lesions, and liver, spleen, and gonads were weighed to compute somatic indices. Selected tissues and fluids were obtained and preserved for analysis of fish health and reproductive biomarkers. Composite samples of whole fish from each station were grouped by species and gender and analyzed for persistent organic and inorganic contaminants and for dioxin-like activity using H4IIE rat hepatoma cell bioassay.

Columbia River Basin↗

USGS2004

Biomonitoring of Environmental Status and Trends (BEST) Program: Environmental contaminants and their effects on fish in the Rio Grande Basin

We collected, examined, and analyzed 368 fish of seven species from 10 sites in the Rio Grande Basin (RGB) during late 1997 and early 1998. Four sites were National Contaminant Biomonitoring Program (NCBP) stations where organochlorine ad elemental contaminants in fish had been monitored from 1969 and through 1986. The other six were USGS-National Stream Quantity Accounting Network (NASQAN) stations where water quality is monitored. The objectives were to document temporal and geographic trends in the concentrations of accumulative organic and inorganic contaminants in RGB fish and the effects of contaminants on the fish; to continue testing the feasibility of incorporating biomarkers (that is, biochemical, histopathological, and other biological indicators of contaminant exposure or effects) into a monitoring program for large U.S. rivers; and to evaluate the compatibility of monitoring methods based on the analysis of fish with those used to monitor water by NASQAN. Common carp ( Cyprinus carpio ; carp) and black basses ( Micropterus sp.; bass) were the targeted species; together, they represented 77% of the fish collected. Each fish was examined in the field for externally and internally visible gross lesions, selected organs were weighed to compute various ponderal and organosomatic indices, and samples of tissues and fluids were obtained and preserved for analysis of fish health and reproductive biomarkers. Composite samples of whole fish from each station were grouped by species and gender and analyzed by instrumental methods for persistent organic and inorganic contaminants and for dioxin-like activity (TCDD-EQ) using the H4IIE rat hepatoma cell bioassay.

Rio Grande basin↗

USGS2000

Biomonitoring of Environmental Status and Trends (BEST) Program: Selected methods for monitoring chemical contaminants and their effects in aquatic ecosystems

This document describes the suite of biological methods of the U.S. Geological Survey- Biomonitoring of Environmental Status and Trends program for monitoring chemical contaminants and their effects on fish. The methods, which were selected by panels of experts, are being field-tested in rivers of the Mississippi River, Columbia River, and Rio Grande basins. General health biomarkers include a health assessment index based on gross observation; histopathological examination of selected organs and tissues; condition factor; and the heptosomatic and splenosomatic indices. Immune system indicators are plasma lysozyme activity and measures of splenic macrophage aggregates. Reproductive biomarkers include plasma concentrations of sex steroid hormones (17β-estradiol and 11-ketotestosterone) and vitellogenin, gonadal histopathology (including reproductive stage and, in females, gonadal atresia), and the gonadosomatic index. Indicators of exposure to polycyclic aromatic and polyhalogenated hydrocarbons are the H4IIE rat hepatoma cell bioassay (performed on solvent extracts of composite fish samples) and hepatic ethoxyresorufin- O -deethylase activity. Stable nitrogen isotope ratios are used to assess the trophic position of the fish and their exposure to sewage and other animal wastes. For each indicator we describe endpoint(s) and methods, and discuss the indicator?s value and limitations for contaminant monitoring and assessment.

Information and Technology Report↗

USGS1999

Biomonitoring of Environmental Status and Trends (BEST) Program: Field Procedures for Assessing the Exposure of Fish to Environmental Contaminants

This document describes procedures used to collect information, tissues, and fluids for documenting the exposure of fish to environmental contaminants. For the procedures described here, fish are captured (preferably by electrofishing) and held alive until processing (generally <1 h). Fish are weighed, measured, and examined for grossly visible external lesions and pathologies. A blood sample is collected by caudal veinipuncture using a needle and syringe. The fish is subdued and it's abdominal cavity opened. The internal organs are dissected from the fish for examination. The sex of the fish is determined by direct observation of its gonads. The liver is weighed (most species) and cut into small cubes and flash-frozen in cryogenic vials, which are stored and shipped in dry ice or liquid nitrogen. Additional liver cubes plus all grossly visible anomalies are preserved for histopathology. The gonads and spleen are weighed, and samples are preserved for histopathology. The kidneys are examined, and histopathology samples collected. A gill sample is also collected and preserved. All remaining tissues are returned to the carcass, which is wrapped in foil, labeled for chemical analysis, and chilled. Individual fish carcasses are composited by station, species, and gender; frozen; and shipped to the analytical laboratory. Procedures are also described for record keeping; processing blood to obtain serum and plasma; flash-freezing samples; cleaning equipment; and preventing the transport of living organisms among waterways. A list of necessary equipment and supplies is also provided.

Information and Technology Report↗