Report: Summer water quality suffered across Island

Toxic algae blooms or low oxygen levels affected every major bay and estuary across Long Island between May and September, triggering rust and brown tides, seaweed blooms and high concentrations of harmful bacteria in shellfish.

The incidents occurred in fresh- and saltwater bodies and were likely linked to nitrogen levels, according to a report released Tuesday by The Nature Conservancy of Long Island and Stony Brook University's School of Marine and Atmospheric Sciences.

"I think we could use the word 'unprecedented' in that we've never seen all these events occurring at exactly the same time and particularly with the same amount of intensity," SoMAS professor Chris Gobler said. "We're talking about an area that goes all the way from Manhattan almost out to Montauk."

Brown tide struck across all of Great South, Moriches and Shinnecock bays, while red tide blanketed Peconic Bay. Both tides, which tint the color of the water, are not harmful to humans but can be damaging to fish, shellfish and eelgrass.

Blooms that cause paralytic shellfish poisoning and blue-green algae were found in Huntington and Northport harbors, and Sag Harbor Cove.

Both types of algae can be toxic to humans and marine life.

Dangerously low oxygen levels were found in western Long Island Sound, Smithtown and Hewlett bays, Mattituck Inlet and Forge River.

SEE PHOTOSSuffolk County Water Authority

Nature Conservancy marine scientist Chris Clapp said the problem can be traced to high levels of nitrogen released by fertilizers, septic tanks and sewage treatment plants.

Pollution from nutrients such as nitrogen and phosphorus affects 15,000 bodies of water throughout all 50 states, according to the U.S. Environmental Protection Agency.

Upgraded septic systems and treatment plants as well as more stringent nitrogen standards are key to recovery, Clapp and Gobler said.

"We are hopeful we can achieve our goals of having healthy, self-sustaining marine resources, not only so that marine life can thrive, but also so our coastal communities . . . can also thrive," Clapp said.

Assemb. Robert Sweeney in August filed the Long Island Water Pollution Control Act, which would create a nitrogen limit of 2 milligrams per liter.

"If we do not act, we can expect a continued decline in water quality that will result in more frequent shellfishing closures, beach closures, fishing restrictions, along with increased contamination of private and public wells," Sweeney said.