As thousands of dead bunker wash ashore, Riverhead seeks fishermen with siene nets to help avoid ‘major’ kill

Officials are scrambling to avoid a major fish kill in the Peconic Estuary due to exceptionally low oxygen levels in the water.

“We’re asking for help from anyone with a haul siene net and permit to get the baitfish out of the water before there’s a major fish kill like we had here several years ago,” Riverhead Supervisor Sean Walter said this afternoon. “If you’ve got the net and the permit, please call Riverhead Police to let us know,” he said. “Please call 631-727-4500 to let police know you can help.”

The town will pay fishermen an as-yet undetermined amount per pound to make the effort economically viable, Walter said, because the market price for baitfish is very low.

“This is an emergency, because if we don’t get the fish out of the water right away, while they’re alive, we’re going to have a major die-off,” the supervisor said. “Disposing of massive quantities of dead fish is a huge problem, as town officials learned several years ago,” he said. “We want to do whatever we can to avoid that problem again. We need to get them out of the water immediately — like yesterday.”

People with nets but no current haul siene permits should call anyway if they can help, the supervisor said. “We will work with the DEC to get the permits.”

Dead bunker have already begun washing ashore by the tens of thousands.

The dead bait fish began to appear on the shores of the river and bay shortly after the diamondback terrapin turtle die-off that’s currently being investigated by the state Department of Environmental Conservation.

Environmental regulators believe the turtle die-off, which began in late April, may have been caused by high levels of saxitoxin, a biotoxin related to the algal bloom caused by Alexandrium, also known as “red tide.”

Dissolved oxygen is essential to marine life.

The supervisor said the state DEC has been out testing the waters of the bay, river and creeks.

“The top three feet of the water has oxygen levels that can barely sustain life,” Walter said. “Below three feet, there’s not enough oxygen for them to live. We need to get them out while they’re still alive.”

There are numerous factors contributing to depleted oxygen levels. The main culprit, environmental scientists have long known, is nitrogen. Nitrogen in the water comes numerous sources, including stormwater runoff, sewage treatment plants and septic systems.

Bunker fish seasonally migrate into the Peconic estuary and its tributaries to spawn, according to Dr. Christopher Gobler of the Long Island Coastal Conservation Research Alliance and a research professor at Stony Brook University’s School of Marine and Atmospheric Sciences.

The bunker migrating into the region “have encountered lethally low oxygen levels at night associated with a mahogany tide of the dinoflagellate, Prorocetrum,” according to the LICCRA website. “Such algal blooms are promoted by excessive nitrogen loading into stagnant water.”

“What we have right now is shaping up to be the perfect storm for a major disaster,” Walter said.