AINEWS
Three States, Three Fish Kills, and Summer Hasn't Started Yet
Three independent fish kills in Minnesota, Arizona, and Massachusetts in roughly the same week are forcing state biologists and watershed managers into an unusually early response.
Three independent fish kills in Minnesota, Arizona, and Massachusetts in roughly the same week are forcing state biologists and watershed managers into an unusually early response.
Contractors in a punt pulled bluegill and crappie carcasses from Como Lake in St. Paul in early June. By the time Marielena Lima, River Science Program Manager at the Charles River Watershed Association, got the call about a separate die-off on the Charles River in Massachusetts, Arizona wildlife officers had already closed San Carlos Lake to the public. Three watersheds, three independent incidents, roughly the same week.
A "fish kill" is what biologists call a sudden, mass die-off in a single body of water. The mechanism behind all three of these incidents is the same: low dissolved oxygen, the kind that happens when surface water heats faster than deeper layers can mix, or when drought and reservoir operations strip oxygen out of a lake or river.
At Como Lake, roughly 1,000 bluegill and crappie died in a single event after a rapid heat influx dropped oxygen levels in the urban St. Paul lake, per local reporting by the Minnesota Star Tribune (as reported by Futurism). Bluegill and crappie are both panfish, common in Midwestern lakes and popular with shore anglers.
In Arizona, San Carlos Lake was closed indefinitely after a major die-off that state wildlife officials said affected approximately 100 percent of the fish population, the result of drought conditions compounded by a nearby dam release, per Arizona state wildlife officials (as reported by Futurism).
On the Charles River, a large die-off of carp followed a pre-summer heat wave that hit fish already exhausted from spawning, per the Charles River Watershed Association, as reported by WGBH (and aggregated by Futurism). Carp are a hardy, bottom-feeding species that often tolerates warm, murky water.
"It's such an early fish kill," Lima told WGBH. "Usually it happens later down in the summer when it's really hot."
Three incidents in three regions in the same week is a suggestive pattern, not a statistical trend. This story rests on three local events, not a national tally. A NOAA, USGS, or state fishery aggregate would be needed to put a number on whether 2026 is tracking above the historical baseline for early-season kills.
What is clear is that the response is happening visibly, and earlier than the calendars suggest. Lake managers are contracting out the grim physical work of pulling carcasses out of urban water. State wildlife officers are closing public access on reservoir lakes. Watershed scientists are explaining to local reporters why a fish that survived the spawn can still suffocate in water that warmed faster than the deeper layers could absorb it.
The work that follows is a stewardship test. State agencies and contractors are doing the visible cleanup now, but the harder question is whether the people and the oxygen-monitoring systems that responded in early June will still be in position when the hottest weeks arrive.