Hundreds of dead bluefish washed up on the shores of Mecox Bay last week, possibly felled by cold temperatures or low salinity levels in the coastal bay.
The bluefish, most between 12 and 15 inches in length and weighing about 2 pounds, were scattered along the shorelines of Burnett’s Cove at the western end of the bay and along much of the eastern shoreline on Friday morning. No other species of fish has been reported to have died.
Scientists from Stony Brook University’s School of Marine and Atmospheric Sciences collected some of the dead fish for testing and took water samples.
Dr. Christopher Gobler, a professor at SOMAS who leads much of the water quality research on the South Fork, said that he suspects the culprit to be the cold temperatures rather than salinity. Salinity levels in the bay were about 15 parts per thousand, compared to more than 31 in the ocean, but that should not have been low enough to kill the fish en masse, he said. More likely, the shallow bay’s cooling waters overstressed the fish.
“A shallow bay like Mecox is going to respond much quicker to temperatures and is probably at a temperature now that the ocean won’t get to until December or even February,” Dr. Gobler said. “We took some [of the fish] up to Stony Brook to the marine animal disease lab. They have a standard battery of tests they do. If there’s some other smoking gun, they’ll turn it up.”
Southampton Town Trustee Fred Havemeyer guessed that the cause could have been dropping salinity levels in the bay and the presence of a normally pelagic species like bluefish in the bay this late in the season. Either way, he said, they needed to be let out of the bay via a cut opened to the ocean.
“The bay has not been opened in some time,” Mr. Havemeyer said. “Species of pelagic fish swim in there when the bay is exchanging, and they grow like crazy because there is so much to eat in there. But normally the bay would have been opened twice since September by now, and they could’ve gotten out of there. The environmental conditions are changing.”
Trustee Bill Pell said that because of low rainfall in the last two months, the height of the bay and the salinity levels have still not reached the thresholds set by Mr. Havemeyer for cutting open the bay.
On Monday, contractors for the Trustees dug open the cut into the bay, but it closed after running for only a few hours. Contractors were due to attempt another opening of the cut on Wednesday morning.
Mr. Havemeyer managed the letting of Mecox Bay for the last decade but gave up the duty earlier this year because of what he has said was withering political pressure exerted by wealthy homeowners in the area regarding the frequency and timing of the cuts. He announced in May that he would not seek reelection to a sixth term on the Trustees.
He has been at odds in recent months with some other members of the Trustees, and consultants for homeowners who live on the fringes of the Trustees-owned beach at the south end of the bay, about when the bay should be opened.