Earlier this month the New York Department of Environmental Conservation closed 2,000 acres of Long Island shellfish harvest areas in Northport Bay, Centerport Harbor and Duck Island Harbor after saxitoxin was found polluting the waterways. Since then, an additional 5,200 acres have been closed after the potentially lethal biotoxin was found in other locations.

The chemical structure of saxitoxin.Officials monitoring the water claim that consuming even a small amount of the tainted shellfish can cause someone to become very sick or can be potentially lethal.

According to Newsday, this marks the second time since 2006 that saxitoxin has been found in the area and it is not yet known what is causing the pollution.