Brown tide threatens marine life off Long Island

Certain microalgae can have a big impact on the future of marine life in the Great South Bay, according to marine biologists.

Dr. Chris Gobler is a marine scientist at Stony Brook University. He has traced brown tides on Long Island back to the mid-1980s. The organism is what caused the downfall of the bay scallops in the Peconic Estuary. 

And now the damaging tide is threatening seagrass and hard clams in the Great South Bay. Gobler said readings since mid-June have shown concentrations as high as half a million cells per milliliter; anything above 35,000 cells per milliliter is harmful.

"Hard clams reproduce once a year in June and unfortunately that's the only time," Gobler said. "If they reproduce into an ecosystem when there's brown tide, the survival of those young clams is very, very low."

Gobler said the root cause is the overloading of nitrogen from septic tanks; 380,000 homes in Suffolk County need to be upgraded.

Steve Kuhn has been clamming on the Great South Bay for the past 50 years. He said he hasn't seen murky brown water this bad in the past four years.

Get breaking news alerts in the FOX 5 NY News app. Download for FREE!

"It makes the clams go to the bottom and it's harder to catch," he said. 

Experts believe after seasons like this one, it can take some time for the clams to make a comeback. 

"When you catch clams, there's nothing behind it for the following year because the brown tide kills all the little clams," Kuhn said. 

Both Nassau County and Suffolk County offer grants to help residents upgrade their cesspools.