Despite millions of bunker fish in Peconic Estuary, town hopes haul of 25,000 lbs. a day will prevent another massive kill

Commercial fishermen seining in the Peconic River have already harvested “at least 350,000 pounds” of bunker from the waters just west of the Cross River Drive bridge — but they say they “haven’t even put a dent in it” because there are so many bunker in the river.

“It’s a losing battle,” said fisherman Lenny Nilson this morning. “I’ve been fishing here since 1986 — so 30 years — and this is the most I’ve ever seen. Last year was the most I’d ever seen and now this year there’s even more,” he said.

Riverhead Supervisor Sean Walter, who successfully lobbied the State Department of Environmental Conservation and the Atlantic States Marine Fisheries Commission this month, to lift the limits on bunker fishing in New York waters, is hoping the harvesting will head off another massive bunker kill like the one that fouled the shores of Riverhead from downtown east to Jamesport. Last year, the town had to hire contractors to clean up the tens of thousands of pounds of dead fish on the shoreline.

“I think we may have solved our bunker problem,” said Walter. “The DEC estimated there are anywhere from 5 million to 20 million bunker in the Peconic Estuary this year,” he said. “And while this may not be putting a dent in that number, we hope it’s removing the bottleneck, so when bluefish start to run the bunker up the river, they can get back out. We’ll have to wait and see. The bluefish are starting to run now,” he said.

Meanwhile, marine scientists are paying close attention to nitrogen and dissolved oxygen levels in the river. Nitrogen is a nutrient for algae — and a rise in nitrogen would intensify a harmful algal bloom that’s already underway. The algae deplete dissolved oxygen in the water, which is essential for marine life. A large population of fish in the same confined space also drive dissolved oxygen levels down.

As it stands now, dissolved oxygen in the Peconic River is already hovering close to the 4.8 mg/l chronic water quality standard for dissolved oxygen established by the DEC. At the end of May through mid-June last year, when the massive bunker die-offs occurred, dissolved oxygen levels fell zero or near-zero for a successive period of days. The minimum dissolved oxygen level to support marine life is 2.

Most of the ingredients for another massive fish kill exist: a vast number of fish, an algal bloom, lower than normal dissolved oxygen levels and higher than normal nitrogen levels.

The one factor that may be staving off a kill thus far is the Peconic River’s relatively cool water temperatures, which briefly popped above 60° F last weekend. In contrast, water temperatures from mid-May to the end of June last year ranged from 65 to just below 80° F. Dissolved oxygen levels fall as water temperature rises.