Officials with the state Department of Environmental Conservation said the concern is that the high volume of storm water runoff - which contains pathogens and other contaminants - could render the shellfish unsafe to eat.
The closures take effect Friday and extend through next Friday. In Southampton, they include all of Sag Harbor and its tributaries. The Town of East Hampton closures include all of Sag Harbor, including a portion of outer Sag Harbor east of the large stone breakwater; all of Montauk Lake (Montauk Harbor) and the southeasterly portion of Northwest Harbor.
The DEC will reopen areas as soon as possible based on tests of water samples to be collected next week. For updates on the closures, call (631) 444-0480.