By Daily Mail (U.S.) | Created at 2026-06-09 01:20:49 | Updated at 2026-06-10 20:46:43
1 day ago
All of the fish have died in an Arizona lake that is usually a popular destination for anglers, prompting officials to close the lake indefinitely.
San Carlos Lake, a man-made body of water about 125 miles east of Phoenix, suffered a 'significant fish kill event' that forced the San Carlos Recreation and Wildlife Department to close the lake on Friday.
The department estimated that 'approximately 100% of the fish population within the lake' died due to 'recent drought conditions, combined with water releases from the dam.'
The lake, which is usually full of largemouth bass, black crappie, bluegill, channel catfish, and brown and rainbow trout, is located within the San Carlos Apache Indian Reservation and was formed with the construction of the Coolidge Dam.
Now that those fish have died, their decomposing remains have made the water toxic, and the San Carlos Recreation and Wildlife Department has prohibited all fishing or other forms of harvesting at the lake, as well as any recreational activity in the water.
Dramatic footage taken by the Gila Herald, as well as footage and pictures shared with Fox10 Phoenix, show large piles of dead fish washed up across the lake's 158-mile shoreline flanked by shallow, brownish-green water.
The fish kill event occurred due to a perfect storm of factors. Recent droughts combined with water releases from the lake and the blazing Arizona desert sun created fatal conditions for the aquatic life.
San Carlos Lake is a reservoir that is legally tied to irrigation demands for farms in downstream communities.
San Carlos Lake in Arizona experienced a 'significant fish kill event' that caused all aquatic life in its waters to die. Dead fish piled on the lake's shores are pictured
Lower water levels caused by a drought and water releases from the lake to irrigate farms in downstream communities created perfect conditions for the fish to suffocate
San Carlos Lake is pictured with lower water levels this year. The shallow water heats up more easily, and warmer water holds less dissolved oxygen that fish breathe
Dry years already deplete the supply of water in the lake, and that depleted supply is compounded by droughts increasing irrigation demands in those downstream areas, which force more frequent water releases from the reservoir.
That makes the lake shallow, which creates a dual challenge for fish. Shallow water heats up more quickly and easily, and warm water holds less dissolved oxygen that fish breathe.
Less water also creates less space for the fish, which quickly use up the remaining supply of dissolved oxygen, causing them to suffocate.
On top of those factors, warm and nutrient-dense water causes algal blooms. Although algae produce oxygen through photosynthesis during the day, it also consumes oxygen at night, mitigating the benefit.
And when the plants die, the decomposition process saps dissolved oxygen from the water, further contributing to fish suffocating.
San Carlos Lake has experienced similar ecological collapses of its aquatic life around 20 times over the past century.
Drought years are a consistent catalyst for the domino effect of shallower water heating up more rapidly and causing the water's dissolved oxygen supply to be stripped away.
During the most recent previous fish kill event at the reservoir in 2018, water levels plummeted below one percent, turning the lake into two small ponds connected by a shallow creek.
San Carlos Lake is pictured in 2010, a year when water levels were high and the lake was healthy
San Carlos Lake is a man-made body of water that was created with the construction of the Coolidge Dam (pictured). The reservoir is located about 125 miles east of Phoenix
Another ecological collapse at the reservoir in the late 1970s caused the water to dry up almost completely and killed an estimated five million fish. It took five years for the lake's ecosystem to rebound after the water was replenished.
It is unclear how long it will take for San Carlos Lake to recover from its most recent fish kill event. The decomposing remains of the reservoir's aquatic life will have to be cleaned up, and fish will have to be reintroduced to restore the population.
The San Carlos Recreation and Wildlife Department has said that it will 'continue to monitor conditions and provide updates as they become available.'
