An unusual winter-spring die-off of a common baitfish species called menhaden around Long Island this spring is part of a larger phenomenon seen from New Jersey to Rhode Island and is tied to the presence of bacteria, fisheries regulators said Thursday.
Menhaden, also known as bunker, are a core fish that feed everything from seabirds and whales to striped bass and bluefish. Large die-offs of the fish are known to occur as waters warm during the late spring, and the fish are pursued up creeks and canals by predators such as bluefish.
One Long Island fisherman who primarily targets bunker said he started seeing the diseased fish amassing last fall, but it's gotten worse this spring, and large amounts of fish are expected in the rivers and creeks in coming days and weeks, with the potential for local impacts.
Hampton Bays fisherman Will Caldwell said he's seen it "everywhere," most recently in an area he fishes in East Quogue. Thus far, he said, he's been able to cull the dead fish from his nets as he hauls the bunker to the surface, but with millions of pounds of more fish expected nearer to creeks and rivers in coming weeks, he expects the problem of dead fish lining the shores to worsen. Caldwell fishes bunker almost exclusively to sell as bait, to markets from Maine to Louisiana.
"Once they get sick, they come to the surface and start spinning and eventually die," Caldwell said. "I saw it happening last fall, but not to this degree. It's apparently pretty bad in Jersey."
Die-offs in the late winter and spring are uncommon, and appear to be tied to a bacteria known as Vibrio, according to the state Department of Environmental Conservation.
Vibrio is a naturally occurring bacteria often found in the summer, the DEC said. It’s not known to be harmful to humans, but the DEC recommends that those who are cleaning up the dead fish wear protective equipment.
The agency said it has received "increasing reports of dead and dying" bunker around Long Island and in the Hudson River.
Samples collected by the DEC and processed by Stony Brook University’s Marine Animal Disease Laboratory "confirmed the presence of Vibrio bacteria in both live and dead fish," the DEC said in a statement to Newsday.
Those same bacteria were found in samples as far away as New Jersey and Rhode Island.
The DEC said it’s continuing to work with state and regional agencies to better understand the die-offs and is requesting citizens who encounter them to email information to firstname.lastname@example.org.
The presence of the bacteria in local waters is expected to continue to contribute to bunker die-offs "in the near term," DEC said.
Christopher Gobler, professor of marine science at Stony Brook University and director of the New York State Center for Clean Water Technology, said while there are "many unknowns" concerning the die-off, the "best guess is that there is a Vibrio bacteria infecting the fish."
While he was unsure the bacteria was positively confirmed in New York, Gobler said, "given the migratory patterns of the fish, it's likely some fish in New York are also infected" by those positively identified bunker infections in New Jersey and Rhode Island.
Fisherman Caldwell in the past has been called on by East End towns to fish the rivers as the bunker amass there to prevent huge die-offs, but he's also been called to Riverhead and Southampton to haul out masses of dead fish after low oxygen kills them.
Selling the dead fish as bait isn't feasible, Caldwell said, so if the problem spreads it could impact the bait market, for lobster trappers in Maine as well as recreational bait shops who sell bunker for striped bass fishermen. May to July is the height of the bunker season, he said.
Caldwell fishes for other species, and said he hopes the current theory that it's only impacting bunker holds true. "I'm really kind of worried about that — if it jumps to another species, that would be bad," Caldwell said. But he's seen seagulls feasting on the fish "every day and I haven't seen a dead seagull yet. Hopefully it stays specific" to bunker.