12 States Suffering Massive Fish Die-Offs

We all know that 2020 was a rough year for humans, but 2021 is shaping up to be a particularly tough year for fish. Across the United States, fish populations are having a hell of a time dealing with issues like intensely hot weather patterns, drought, and algal blooms. In fact, it seems like every time we check the news, another mass fish kill is plaguing a different part of the country. In an attempt to bring attention to fisheries everywhere, we’ve compiled a list of fish kills from the East Coast to the West.

Florida Florida is getting hit harder than most anywhere else in America for fish kills this summer. Many of Florida’s fishes are dying for the same reasons as in other parts of the country: lack of dissolved oxygen, in this case due to algal blooms. Florida’s red tide and blue-green algaes tends to result from rains flushing fertilizers and pollutants into lakes, rivers, estuaries, and bays—and Florida’s rainy season is just starting. Florida is also struggling with a complex and changing freshwater management system around Lake Okeechobee that plays a role in the dispersal of nutrients throughout waterways.

So far this summer, more than 3 million pounds of dead fish have been removed from the Tampa Bay area. The red tide bloom has been worse in this area than it has in more than 50 years. Dump truck loads of forage fish, sportfish like tarpon, even massive goliath groupers and large marine mammals like manatees have been washing ashore.

A large spill from the Piney Point phosphate plant could be throwing fuel on this fire, but it’s likely not the sole contributor to these mass die-offs. Phosphate and nitrogen are key ingredients in fertilizers used to maintain landscaping, golf courses, and agriculture, which eventually runs off into water systems. No surprise, the same nutrients that make hyper-green lawns have the same effect on o estuaries.

Millions of fish were found dead in Crane Creek in Melbourne. The cause of this mass die-off is likely blue-green algae blooms.

In Boca Raton 1,000 dead shad washed up on the banks of Sabal Lake. Once again, the culprit was a lack of dissolved oxygen due to a prolonged drought followed by the season’s first rains. This also likely contributed to a blue-green algae bloom, which produced an outbreak of cyanobacteria around West Palm Beach that’s currently threatening the public health and the safety of drinking water.

Scores of colorful tropical reef fish, like triggerfish, parrotfish, and angelfish, are washing up on Palm Beach. The exact causes of this fish kill have not yet been announced, but divers in the area report that water temperatures dropped 20 degrees, from the mid-80s to the mid-60s, in less than a week. Such erratic shifts are rare but can happen when winds, currents, and eddies conspire to cause upwellings from deep water offshore. The previous week a strong current from the north was passing the outer edge of the reef, which may have contributed to the stark temperature change.

Klamath River Basin: Oregon, California While Florida is seeing tons of fish wash ashore all at once, this river system has been experiencing a slow, sure exhaustion of native fish populations for years. Dams are choking the flow of cold water necessary for these salmonid species survival, irrigators are taking much of that water, and this exhaustively hot summer is making the problems even more apparent.

The Klamath River flows across the Oregon-California border and was once a thriving salmon and steelhead fishery. But the basin is currently experiencing extreme drought, the worst it's seen in four decades. Thesalmon populations have also been struggling for years due in part to a parasitic disease called Ceratonova shasta. The parasite has become a significant problem recently due to the combination of lower water, warmer temperatures, a lower water table, and various impacts of dams.

The parasite can kill salmon of all age classes when concentrations reach a certain level. This year, the fish kill began in early May and now 97% of juvenile coho and chinook salmon are testing positive for the parasite. Seventy percent of the observed juvenile fish have died. The parasite is predicted to completely wipe out an entire year-class of fish whose numbers have already plummeted in the past several generations.

“Our monitoring traps are full of dead juvenile salmon,” Toz Soto, fisheries program manager for the Karuk Tribe, told Counter Punch. “The few fish still alive are infected with disease. It’s a catastrophic blow to the fishery and Karuk culture.”

The largest dam removal and river restoration effort evere is currently underway on the Klamath. Four hydroelectric dams will be removed, which will free 300 miles of river, allow, fish to access spawning grounds, and lower water temperatures.

Columbia and Snake Rivers: Washington, Oregon, Idaho Salmon are also dying en masse in the Columbia and Snake rivers from rising water temperatures. The fish are literally rotting to death because the water is just too hot. What used to be naturally flowing reaches are now stagnant reservoirs, which heat to unhealthy levels in the summer as Chinook and sockeye try to pass through them.

Many conservationists say that these extreme water temperatures and potential run losses confirm the need for immediate, bold action, including removal of the four dams on the Lower Snake.. River restoration is the best hope these native fish have to evade extinction.

To hear more on this issue, listen to this episode of the MeatEater Podcast where Idaho’s Representative Mike Simpson elaborates on his proposal to remove dams from the Snake River.

Oregon has implemented closures for certain rivers in response to the current drought and high temperatures in order to protect fisheries. “There is a tough summer and early fall ahead for fish, and we want to take steps to help them survive,” said Shaun Clements, ODFW deputy administrator for inland fisheries. “We appreciate anglers following the regulations and being flexible with their plans to help fish this year.”

Minnesota Lake Pokegama residents woke up to hundreds of fish washed ashore on July 22—another instance of low water levels and hot temperatures causing algae blooms that deplete oxygen.

The DNR is reporting piles of dead fish washing up in lakes across the northern tier of the state and even in the Minneapolis suburbs. According to Tom Burri, a limnologist for the Minnesota DNR, “This is a rare occurrence. We have such extreme drought conditions right now.”

Burri also said that rapidly warming water temperatures are putting stress on fish and making them more susceptible to infections.

Delaware More than 200,000 juvenile menhaden died in Rehoboth Bay also as a result of low levels of dissolved oxygen. Chris Bason, executive director for the Delaware Center for Inland Bays, describes Rehoboth as a very unhealthy estuary.

Miles and miles of concrete canals were cut into the bay generations ago to allow for easier boat passage and docking, which destroyed the natural salt marshes. Whereas those marshes were historically flushed by tidal flow, nutrient- and toxin-laden runoff from lawns and agriculture now gets trapped in the canals, which leads to massive fish kills like this one.

Missouri Brush Creek in Kansas City has lost an estimated 52,000 fish so far this summer after oxygen levels dropped to one part per million, which, according to local fish biologist Jake Colehour, is lethal to nearly every fish. For context, five parts per million is considered good oxygen saturation for most warmwater fishes in the summer.

The vast majority of the fish that died were sunfish, but common and silver carp also went belly up (not that anyone complained). If carp are dying, you know it’s bad. While fish kills happen nearly every summer in this creek, this year is the worst that anyone has ever seen.

Pennsylvania Thousands of fish and crustaceans died in Chartiers Creek on July 15. This kill impacted warmwater species such as suckers, carp, crayfish, and various minnows. The Department of Environmental Protection believes a pollutant to be involved with this kill, likely either a pesticide or herbicide. Investigations are currently underway.

Virginia Little Creek experienced a fish kill of about 8,000 after a forklift operator at Shearer’s Foods punctured a 250-gallon drum of lye. The company alerted the DEQ immediately, but the pollutant quickly flowed down the stream. The caustic substance killed sculpin, darters, and minnows.

Louisiana Lake Pontchartrain fishermen blame algae blooms for the “worst season some have seen in a lifetime,” according to one local angler. Fish, crabs, and shrimp are washing ashore dead and the fishermen have not had successful hauls this summer. In addition to fertilizer runoff, Pontchartrain has another factor adding to algal growth.

“There are a lot of homeowners that we work with on the north shore,” said Brady Skaggs, the water quality program director for the Pontchartrain Conservatory. “They're not tied into a sewerage system so every time they flush the toilet or flush the drain, those materials are going into a storm water ditch, which goes into a tributary of Lake Pontchartrain.”

Montana Montana is also feeling the effects of severe drought and high temperatures. Every major river in Southwest Montana currently is under either a hoot owl restriction (which closes rivers to fishing from 2 p.m. until midnight) or is completely closed to anglers. Famous rivers including the Jefferson, Yellowstone, Madison, and Gallatin have emergency closures in place because water levels are so low and temperatures are so high.

“The famed Madison River, which I have fished probably more than any other body of water in the country, experienced an acute die off of whitefish, trout, and suckers amid water temps soaring into the mid 70s. In June,” Bent Podcast host Miles Nolte said. “I will not be fishing the Lower Madison at all until water temps get below 65 degrees, and I sure hope other people will consider doing the same.”

Anglers have also reported seeing brown trout with the telltale white markings of saprolegnia fungus, sometimes referred to as cotton molds because infected fish appear to have billowy white cotton on parts of their skin. The fungus can be fatal, especially when fish experience other stressors like elevated water temperature. A string of consistently warm summers has greatly diminished the trout population in Lower Madison, especially brown trout, the numbers of which are at a 20-year low.

What You Can Do If you’re unsure about conditions or restrictions in your area, put in a call to your local fisheries and wildlife management agency or check their website for details. It’s the time of year that we all want to be on the water, but it’s also important to prioritize the health of our fisheries so that we continue to enjoy these resources for generations.

“Personally, I will either seek out water where conditions are favorable—like high mountain creeks or deep water lakes—or only target fish I’m intending to harvest and quit fishing after I’ve caught enough for a meal. Catch and release just isn’t ethical right now in a lot of places,” Nolte said. “Sure, you might let the fish go, but they’re not going to survive. You just get to avoid confronting the reality of how many fish you’re killing. Then again, I might completely change up my program and spend this summer focusing on fish that don’t mind heat and low oxygen—bring on the carp, snakehead, bowfin, and gar.”

This article likely missed at least a few recent fish die-offs. If we failed to cover one in your area, we apologize. There are so many it’s difficult to keep track of them all. If this article felt redundant, that’s because it is. Fish are dying because it’s too hot, there isn’t enough water, pollutants are entering waterways, and algal blooms are suffocating fish. For more information on what may be contributing to these factors, check out this resource.

“Even if the fish around your local lake, pond, river, creek, or shoreline aren’t bobbing their white flags on the surface in mass surrender, they still might be feeling the stress of heat, low oxygen, algal blooms, or other confounding factors,” Nolte said. “If your fish are having a rough season, like ours are here in Montana, consider changing your habits. We all love summer fishing—I certainly do—but keeping the rods bent through the dog days isn’t worth potentially threatening the quality of your fishing future.”

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