USGS: Atrazine affects fish reproduction

RESTON, Va., May 19 (UPI) -- U.S. Geological Survey scientists say they've discovered the popular organic herbicide atrazine affects fish reproduction.

"Concentrations of atrazine commonly found in agricultural streams and rivers caused reduced reproduction and spawning, as well as tissue abnormalities in laboratory studies with fish," said USGS scientist Donald Tillitt, who led the research.


Tillitt said fathead minnows were exposed to atrazine at the USGS Columbia Environmental Research Center in Columbia, Mo., and observed for effects on egg production, tissue abnormalities and hormone levels. The fish were exposed to concentrations ranging from zero to 50 micrograms per liter of atrazine for up to 30 days.

Study results showed normal reproductive cycling was disrupted by atrazine and fish did not spawn as much or as well. Researchers found total egg production was lower in all atrazine-exposed fish, with abnormalities seen in reproductive tissues of both males and females.

The USGS said atrazine is one of the most commonly used herbicides in the world and is applied to most U.S. corn, sugarcane and sorghum acreage to stop broadleaf and grassy weeds.

"The reproductive effects observed in this study warrant further investigation and evaluation of the potential risks posed by atrazine, particularly in wild populations of fish from streams in agricultural areas with high use of this herbicide," Tillitt said.


The study appears in the journal Aquatic Toxicology.

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