August 4, 2021 — It’s the time of year when fish abound in the region’s rivers, lakes and Long Island Sound, and also a time when some fish are dying.
While it’s an annual event, die-offs of menhaden, or bunkers, is most likely larger this year because of all the rain the state had in July, according to David Molnar, senior marine fisheries biologist with the state Department of Energy and Environmental Protection.
Another factor is that because of fish management, “menhaden are at an all-time high abundance. They are the most abundant fish in the sea,” he said.
Bunker serve as food for larger fish, ospreys and whales, as well as fertilizers, animal feed and bait for crab and lobster, according to the National Oceanic and Atmospheric Administration.
They are saltwater fish but all the rain has reduced the salinity in the rivers, Molnar said. “Typically, the saltwater wedge in the Connecticut River can go all the way to Haddam,” he said. Now, it’s fresh water all the way to the breakwater.
At Shoreline towns such as Lyme, “as far as you can see are schools of menhaden,” Molnar said. “It’s an amazing sight. There are thousands and thousands of them.”
But in Guilford, for example, the problem in the West River, which Molnar called “a beautiful system, good water quality,” is that too many fish crowd in, creating school-induced hypoxia. “As the water temperature increases, they consume all the oxygen” and become stressed. Then, “diseases and parasites that they harbor” are able to flourish, killing even more fish.
Molnar said the bunker have been swimming in the West River since May, but the heavy rains in July brought too much fresh water, pushing the salt water out. “This is the third-wettest July in 100 years. That’s a lot of water,” Molnar said.