More wildlife are experiencing strange reproductive abnormalities, but why? In a study released last year, the U.S. Geological Survey and U.S. Fish and Wildlife Service (USFW) tested male smallmouth and largemouth bass from 19 National Wildlife Refuges. The researchers found that 85% of the smallmouth bass “had signs of female reproductive parts.” Of the largemouth bass, 27% were intersex. What could be causing this?
Luke Iwanowicz, a USGS research biologist and lead author of the paper, says:
“It is not clear what the specific cause of intersex is in these fish. This study was designed to identify locations that may warrant further investigation. Chemical analyses of fish or water samples at collection sites were not conducted, so we cannot attribute the observation of intersex to specific, known estrogenic endocrine—disrupting chemicals.”
Referencing an older study also examining examining Intersex occurrence in freshwater fishes in the U.S. between 1995 and 2004, Fred Pinkney, a USFWS contaminants biologistThis post was originally published on this site