Flushing Out The Problem

In the 1970s, New York’s Great South Bay produced half the clams eaten in the United States. Clams are not only tasty—they are also living water filters. Unfortunately, overharvesting and the impacts of development decimated populations in the bay over time. Water quality declined and clam populations spiraled downward.

To reverse this outcome, The Nature Conservancy began stocking millions of hard clams in Great South Bay in 2004. Monitoring showed a troubling trend: Clams were reproducing in the fall and juveniles were surviving the winter, but only limited numbers made it through the summer growth season. Research revealed a disturbing cause: Hundreds of thousands of cesspools and septic systems were overloading waters with nitrogen.

Septic tanks and cesspools are not pleasant topics. But conversation about them could no longer be ignored on Long Island. Drinkingwater quality was at risk and algae growth was supercharged, making it difficult for clams, other shellfish and fish to survive.

TNC got to work again, partnering with advocates, organizations and decision-makers from federal, state and municipal governments. Thanks to this decades-long effort, significant progress has been made to drastically reduce nitrogen pollution by modernizing wastewater infrastructure. A critical policy win in the November 2024 election will bring back the island’s once bountiful shellfish, seagrasses, salt marshes and wildlife.