Summer is right around the corner, which means many of us will head out to Long Island for clams bakes and time on the beach. But there’s a problem lurking in the waters around the Great South Bay. According to studies from The Nature Conservancy, excessive nitrogen is polluting the waterways.
“We have these symptoms in many places, either harmful algal blooms, some of which are actually toxic to fish and wildlife, some of which are toxic to people,” said Carl LoBue, The Nature Conservancy’s senior marine scientist on Long Island. “So that actually has a big impact on which fish enter our bays, which fish are healthy to eat. And then in some places, like Western Long Island Sound where the water is deep, we get hypoxic dead zones, like you might hear about in the Gulf of Mexico.”
Scientists at The Nature Conservancy became particularly focused on this problem in the Great South Bay through a shellfish restoration project that began 10 years ago. At that time, the organization came into possession of 21 square miles of bay bottom. Previously owned by an oyster company and then a bank, the underwater land had been strip-mined of shellfish, so scientists decided to repopulate the area with clams.
“Half the clams eaten in this country came from Great South Bay at one point,” said Nancy Kelley, Long Island chapter director of The Nature Conservancy. “Annual harvests in the 1970s were upwards of 700,000 bushels a year. That’s [a] 99 percent decline, down to about 10,000 bushels [now].”
After a few years, though, evidence showed that the reintroduced clams weren’t doing as well as they’d expected. “Some years, when we tested how many clams were actually growing, we saw some positive results, other years, not so much,” said Kelley. “And clearly there was a problem with our water quality because these systems just weren’t sustaining healthy populations of shellfish.”
Scientists knew nitrogen pollution was a problem in many places throughout the world, but 65 percent of nitrogen leaking into the Great South Bay came from a particularly local source. “The big surprise was that the main culprit, the main source of this excessive nitrogen was from residential home septic systems,” said Kelley, pictured right.
Now the organization is working on getting residents in problem areas to replace old septic systems with new ones that are designed to prevent excessive nitrogen leakage. That’s not a small feat given the individual investment required by homeowners.
“Recent polling indicates that 85 percent of Long Island voters strongly support tougher water quality standards if it means that less nitrogen will enter our waters,” said Kelley. “So they’re willing to be a part of the solution. They’re also willing and understand that it’s going to cost some money.”
According to Kelley, the problem is one that simply can’t be ignored any longer. “Last year, 13,000 acres of shellfishing grounds were closed because of these toxic algal blooms,” she says, adding that there were 1,100 beach closures last year, and that number is growing. “We realize that the solution lies in the folks who live on Long Island.”