Scientists Stumped By Die-Off Of Bluefish In Shinnecock Bay

Scientists say they are at a loss to identify what might have killed hundreds of bluefish in eastern Shinnecock Bay last week.

More than 2,000 pounds of 3- to 5-pound bluefish washed up on beaches along the northern shores of the bay between Sunday and Tuesday. Most appeared to have been dead for days before they started washing up.

“Sunday, a few of them started to appear in the bay when we were going out to set nets about sunset,” said Ed Warner Jr., a bayman and a Southampton Town Trustee. “On Monday night, we went out and there were dozens, and by Tuesday they had washed up on the beach from Atterbury to Far Pond and as far west as Peconic Road. It looked like they must have died in the middle of the bay, and the south wind blew them to shore.”

Mr. Warner said he estimated that the fish had to have been dead for at least three or four days based on their state of decomposition and how long it would have taken them to float to the surface as decomposition released gases trapped inside the carcasses. He said that maintenance workers for the Trustees removed more than 1,000 pounds of the dead fish from the beaches before the holiday weekend.

Dr. Chris Gobler, a marine scientist at the Stony Brook University School of Marine And Atmospheric Sciences, said that he had sent two of the fish to the university’s Marine Animal Disease Laboratory, but the advanced stage of decomposition did not offer much hope of identifying any harmful substances that could have caused the deaths. “By the time they get to that stage, there’s little you can do to determine what killed them,” he said.

Dr. Gobler said perhaps the most bizarre thing was that it was only bluefish that died. If the cause was some environmental event, like the drops in oxygen or spikes in toxic or choking algae that are typically behind fish die-offs, he would expect to see other species also.

The scientist said he’d asked Mr. Warner if it could have been a commercial fishing boat from the docks by Shinnecock Inlet that dumped a large haul of bluefish. But Mr. Warner said that with bluefish selling at market for upward of 80 cents per pound, it was highly unlikely that any fisherman would discard them.

“Plus, they came from the middle of the bay. There’s nobody fishing out there at all,” Mr. Warner said. “It really makes you scratch your head.”