He cited pesticide runoff from the American Midwest as a major pollutant of streams in Louisiana.

The chief environmental risk, the report said, is contaminated drinking water from pesticide runoff.

Scientists had thought that the size of the raindrops or the force with which they fall might also be important factors in pesticide runoff.

Farmers upstate, with financial assistance from the city, work to reduce pathogen, nutrient, sediment, and pesticide runoff.

But golf organizations point to studies showing minimal pesticide runoff from courses, compared with residential neighborhoods.

The spread of agriculture and industrialization dealt another blow, as pesticide runoff killed thousands of fish.

Anthony Montrone, one of the principal authors of the report, said the researchers decided to exclude issues like pesticide runoff and habitat destruction.

The Darling has been in poor health, suffering from overuse of its waters, pollution from pesticide runoff and prolonged drought.

Water quality has also deteriorated due to pesticide runoff.

Erosion reduces the storage capacity of the reservoir and water quality has been reduced by pesticide runoff.