Over the summer, hordes of dead fish were spotted floating along the Hudson River from Manhattan up to Haverstraw Bay in Rockland County. Experts said at the time it was due to a fatal mix of "the sun, the heat, the sewage, and the lack of rain synergistically working together." Everything seemed to go back to normal by late summer... at least until now.

Since Thanksgiving weekend, there have been over 100 reports to environmental group Riverkeeper about dead fish turning up once again in the Hudson and in other bodies of water around the area. There have been sightings of the dead and dying Atlantic menhaden fish—better known as bunker—in Riverside Park, New York Harbor, Newark Bay, and on the shorelines of Red Hook, Englewood Cliffs, the Upper West Side, Piermont Pier, Tarrytown, Ossining and Cortlandt.

Amanda Fucello was standing in Bushwick Inlet Park in Williamsburg around 9 a.m. at the start of December when she saw that "dozens of fish suddenly washed up on the shore and started merging on the surface, flopping around and dying. There [were] tons of seagulls landing, not sure if this is something that is going on up and down the river or if it’s a simple as a fishing net broke or something has caused them to suddenly die in the dozens."

About a week later, she wrote Gothamist to say she saw the same thing happening again.

A spokesperson for the Department of Environmental Conservation (DEC) said in a statement that they have received reports about the fish dying en masse all over the area: "Die-off events of Menhaden are not unusual and there are various naturally occurring causes for these events. Fish, such as bunker, that swim in large schools are particularly vulnerable to low dissolved oxygen, certain environmental pressures, and pathogens."

The DEC and Riverkeeper have collected "dying but not dead" fish samples and are testing them to get a better understanding of what is happening now.

Riverkeeper Patrol Boat Capt. John Lipscomb, who has worked there for over 20 years, explained that bunker have not gotten the respect they deserve—they are a critically important part of the food chain that turns plankton into flesh, and then in turn become food for the likes of tuna, striped bass, blue fish, and other predators. They have been over-harvested for their fish oil for years now, and a wide coalition of environmental groups are trying to have that changed before it destabilizes the food chain.

Then over the summer, the combination of heat, lack of rain and other environmental factors led to bunker running out of oxygen and in essence suffocating in huge amounts. "In 20 years of patrols, I've never seen an early summer die-off of bunker like this year, and it's not like it happens every year," Lipscomb told Gothamist, saying they have been inundated with reports of dying bunker in 2020. "And for every person who reports a sighting, there's probably 100 people who saw dead or dying fish and is wondering what the hell is going on."

Because it is clearly not nearly as warm outside as it was last summer, it seems unlikely that temperature and oxygen are the cause of this latest problem, but Riverkeeper is waiting for the necropsy results before conjecturing about what may be causing the die-off.

The thing that has been remarkable, and in its own way encouraging for Lipscomb, is seeing the outpouring of concern from the public about these fish. "We get all kinds of calls to our hotline, they're always driven by some level of concern, but for my team that takes these calls, the thing they remark to me again and again is that the public are really upset to see these dead fish," he said.

"In these reports to us is voiced this deep concern for the river—these fish are the embodiment of the river to these people, and when they see them dying, it's heartbreaking. And for people to emotionally appreciate the struggles of these fish is a giant leap in the right direction," Lipscomb continued. "It's easy if you see a chipmunk that's hurt, but you see fish hurt, it's removed from our warm-blooded, above-the-surface life. But these people are genuinely very upset, and that's worth noting. It's also a good sign. The river is mute: it can't call out, it can't say 'help.' So when these people connect emotionally like that, that's exactly what the river needs."