Pesticide runoff impacts salmon recovery

WASHINGTON, Dec. 21 (UPI) -- Reducing pesticide runoff from farms and homes could speed the recovery of wild salmon populations in the western United States, biologists said.

Even short-term, seasonal exposure to pesticides may limit the growth and size of wild salmon, whose numbers have been declining for years, said David Baldwin of the National Oceanic and Atmospheric Administration.

Baldwin's team used existing data on the impact of common pesticides on salmon to devise a computer model that calculated productivity and growth rate.

One scenario predicted that salmon not exposed to pesticides would see a 523-percent increase in numbers over 20 years when compared with salmon exposed to pesticide levels found today in rivers and basins, NOAA said in a release Friday.

Pesticides have been found to reduce the activity of acetylcholinesterase, an enzyme in the salmon brain that causes them to feed less when exposed to pesticides.