Septic systems and nitrogen pollution are killing the island’s marine heritage

By Brett Walton
Circle of Blue

Thousands of dead bunker fish and hundreds of diamondback turtles washed ashore last May in Peconic Bay on the east end of Long Island, New York. Fed by warming waters and a stream of nitrogen, a foul bloom of algae had so depleted the estuary of oxygen that marine life suffocated. The waters of the bay swirled red and brown.

The late-spring algae bloom was the beginning of a seasonal occurrence that has become distressingly common: a toxic summer in the waters of Long Island, the claw-like banner of land that extends 190-kilometers (118-miles) from Brooklyn to the Hamptons. Aureococcus, or brown tide, covered the south shore in June. Cochlodinium, or rust tide, appeared in Shinnecock Bay and Sag Harbor in early September. Between Memorial Day and Labor Day, at least 15 lakes were overwhelmed by microcystis, a toxin produced by blue-green algae.