Fishermen who hauled roughly 700,000 pounds of bunker from the Peconic River this spring have helped avert another major fish kill, a town supervisor said.

Will Caldwell led three crews who set seine nets from early April through mid-June to prevent another die-off of bunker, also known as menhaden, after last year’s fish kills left hundreds of thousands rotting on the riverbanks.

“If he didn’t do that, we would have probably had one or two massive fish kills” this year, Riverhead Town Supervisor Sean Walter said Thursday. “We averted a pretty nasty June along the Peconic River.”

Most of the bunker harvested from the river and other areas of Peconic Bay were shipped to Maine for lobster bait or sold locally for bait, fishermen said.

One minor die-off of about 1,000 fish occurred this month, but none since, Caldwell said Wednesday.

Caldwell said he and the five fishermen working with him felt they were netting just enough bunker to keep the fish from again overwhelming the river, depleting the oxygen and dying of asphyxiation.

“It was so close,” said Caldwell, owner of C Well Fish LLC in Aquebogue.

Riverhead officials budgeted $30,000 to subsidize the fishermen’s work at a rate of 4 cents per pound, saying the low price of bunker would not otherwise warrant such intense fishing.

Officials in Southampton Town, which borders the river to the south, have agreed to reimburse Riverhead at a rate of 1 cent per pound, and state officials have agreed to contribute 2 cents per pound, Walter said.

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In 2015, nearly 300,000 bunker suffocated in May and June as they crowded the river and found themselves trapped by predators. Researchers said algal blooms linked to nitrogen pollution also contributed to the die-offs.

Walter said town officials will continue to monitor concentrations of fish in the river. Caldwell said he believes a similar effort will be necessary in the fall because bunker populations have swelled along the East Coast, including in Peconic Bay.

“If you flew over the bay in a plane today, you would see schools of bunker,” he said.