Were pesticides present in stream bed sediment and fish?
In streams, organochlorine compounds, such as DDT and their degradates and by-products were found in fish and bed-sediment samples from most streams in agricultural, urban, and mixed-land-use watersheds and in more than half the fish from streams with predominantly undeveloped watersheds. Most of the organochlorine pesticides have not been used in the United States since before the NAWQA studies began, but their continued presence demonstrates their persistence in the environment. More than 90 percent of fish-tissue samples from streams with developed watersheds had one or more detectable compounds and most sites had detections in bed sediment as well.
