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Massive Brown Tide On Long Island Finally Clears

Seth Wenig
The Great South Bay as seen from Bay Shore, New York, in 2010.

One of the largest brown tides in Long Island history, which extended from Southampton into Nassau County, has finally cleared in the Great South Bay, meaning safety for local marine life.

The brown tide algal blooms resemble coffee with milk — and while it poses no threat to humans, it caused a die-off of early-stage clams and sea grass.

Christopher Gobler of Stony Brook University told Newsday that the brown tide, which first appeared in May, was one of the longest-lived he has seen on Long Island.

It was caused by excessive nitrogen runoff from septic systems and fertilizers.

But as water temperatures moved into the high 70s in recent weeks, the bloom began to die off, though authorities say it could return.

This was the largest algal bloom on Long Island since 2008.