HEMPSTEAD - Scientists say harmful algae blooms took a toll on the quality of Long Island's water this summer.

A study by Stony Brook University Professor Dr. Chris Gobler shows Hempstead Harbor, Quantuck Bay, Eastern Moriches Bay, Western Flanders Bay and the Forge River all had some of the worst water quality on Long Island.

Gobler says the toxic mix of algae and fecal matter in these waters is caused by antiquated cesspools that are leeching nitrogen into the surface water.

"We have seen things get worse so if we don't do anything, some of these areas will continue to degrade," says Gobler.

Due to Long Island's declining water quality, environmentalists say fish and shellfish have declined by more that 90 percent since 1980.

"We are at a precipice where we can make the changes and bring back what's left, or see than decline continue and lose our fisheries forever," says Gobler.