Marine life depends on nutrients to grow. Likewise, not all heavy metals are bad. Recent experiments at the Moss Landing Marine Stations in California showed that dumping controlled amounts of iron filings in the ocean created a 40-fold increase in zooplankton, the first link in the aquatic food chain. Our laws should not presuppose science, but instead be based on the latest science. Second, pinpoint the sources of pollution.
Nutrient runoff does indeed come from agricultural sources, but more comes from urban sewage.
Municipal waste-water treatment plants remove only part of the nitrogen in city sewage. They are sources of nutrient runoff, as are auto emissions and salt treatment for icy sidewalks and streets. Third, keep perspective on the economic cost of regulation. To be sure, the environmental lobby's newfound concern for bottom-line economic costs is a ruse to draw attention away from the government's spending spree. Fourth, monitor water quality.