WOODBURY - Long Islanders who went out on the Great South Bay over the holiday weekend may have been surprised to find the murky, coffee-colored water that's the telltale sign of brown tide.

The algae bloom flared up in late June, and environmentalists say it's worst in the western part of the bay. Local marine scientists are surprised to see the brown tide arrive so late in the season, especially after the bay looked so clear just a few weeks ago.

Experts say the heavy rains that June brought are likely to blame. They flushed nitrogen into the water, creating ripe conditions for the brownish algae to thrive. Environmentalists say they're worried what the murky water could mean for the area's already weakened shellfish population.

There is a spot of bright news for the darkened waters, however. Experts say the new inlet that was created by Superstorm Sandy is flushing clean water into the Great South Bay, preventing it from getting too bad. And if the high heat persists, the algae may be killed off, as it can't survive in super warm water.