YAKIMA, Wash. – Low pesticide concentrations, generally below levels that violate state or federal water quality standards, have been detected in five Washington watersheds where salmon are found, according to a new study.

The three-year study by the state departments of Ecology and Agriculture, which was conducted from 2006-08, concluded that the pesticide concentrations are not likely to directly affect salmon. However, levels found at some sites may harm aquatic life that serves as a food source for salmon, some species of which are threatened or endangered.