Biology - Contaminant Biology Program
Endocrine DisruptionThe ability of environmental contaminants to affect reproductive and developmental processes in fish and wildlife species has long been known. An increasingly persuasive body of evidence indicates that many of these chemicals may be causing such effects through interference and disruption of normal endocrine function. Field observations have correlated abnormal sex organ morphology, unusual sex hormone levels and ratios, and altered physiological and biochemical processes with exposure to environmental contaminants. These developmental end points are under the control of the endocrine system, lending support to the hypothesis that environmental contaminants may disrupt endocrine function.
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River otter baculi. USGS biologists in Corvallis, OR, studied river otters in the lower Columbia River and found a correlation between the size of the baculum, a bone found in the penises of certain mammal groups, and PCB concentrations.
Egg and sperm cells of fish. USGS biologists have found "intersex" fish (those with both eggs and sperm) in many aquatic environments throughout the country. August 2006 testing at three tributaries emptying into the Potomac revealed that more than 80 percent of all male smallmouth bass found were growing eggs, according to Vicki S. Blazer, a fish pathologist within the U.S. Geological Survey. Listen to USGS CoreCast "Endocrine Disruption: Sex-Changing Fish and More" to learn more about the effects humans are having on aquatic life by introducing chemicals and waste products into lakes and streams. Featured PublicationsGoodbred, S.L., Smith, S.B., Greene, P.S., Rauschenberger, R.H., Bartish, T.M., 2007, Reproductive and Endocrine Biomarkers in Largemouth Bass (Micropterus salmoides) and Common Carp (Cyprinus carpio) from United States Waters: U.S. Geological Survey Data Series 2006 - this report provides a national and regional benchmark and a basis for evaluating biomarkers of endocrine and reproductive function.
Hinck, J. E., Blazer, V. S., Denslow, N. D. Gross, T. S., Echols, K. R., Davis, A. P. , May, T. W., Orazio, C. E. , Coyle, J. J., Tillitt, D. E., 2006
Biomonitoring of Environmental Status and Trends (BEST) Program: Environmental Contaminants, Health Indicators, and Reproductive Biomarkers in Fish from the Colorado River Basin: U.S. Geological Survey, Scientific Investigation Report 2006-5163 |
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