Skip to main content
U.S. flag

An official website of the United States government

2004-2010 Chesapeake Bay Smallmouth and Largemouth Bass Estrogenic Biomarker Data

July 30, 2020

The data was gathered to document the extent and severity of biomarkers of exposure to estrogenic chemicals in smallmouth and largemouth bass. Samples were collected from 2004 through 2010 at sites in five watersheds within the Chesapeake Bay watershed. A total of 281 largemouth bass were collected from the Potomac, Susquehanna, Patuxent and Rappahannock rivers and 1,384 smallmouth bass from the Potomac, Susquehanna and James. Fish were collected by boat electroshocking, euthanized in the field, weighed, measured, a blood samples collected and a necropsy completed that included documenting any visible abnormalities and collecting tissues for histopathology. Plasma obtained from blood samples was analyzed for vitellogenin, a yolk precursor widely used as an indicator of estrogenic exposure in immature and male fishes. Five to seven sections of testes were processed for microscopic analyses, embedded in paraffin, sectioned at 5 m, stained with hematoxylin and eosin. The presence of testicular oocytes was noted and the severity rated from 1 to 4 based on number and arrangement of oocytes.

Publication Year 2020
Title 2004-2010 Chesapeake Bay Smallmouth and Largemouth Bass Estrogenic Biomarker Data
DOI 10.5066/F7CF9P97
Authors Vicki S Blazer, Ryan P. Braham, Heather L Walsh, Luke Iwanowicz, James D. Hedrick, Geoffrey D. Smith, Stephen J. Reeser, John E. Mullican
Product Type Data Release
Record Source USGS Digital Object Identifier Catalog
USGS Organization Eastern Ecological Science Center at the Leetown Research Laboratory