San Carlos Lake has been closed until further notice after a massive fish kill wiped out approximately 100% of its fish population, according to the San Carlos Recreation and Wildlife Department.
The die-off, attributed to critically low oxygen levels caused by shrinking water levels and drought conditions, comes less than a year after the lake dropped below 1% capacity.
However, it’s worth noting this is not the first time this has happened at San Carlos Lake. The last fish kill that occurred there was in 2022, said Daniel Juan, the department’s senior biologist, with three or four other fish kills having occurred between 2010 to 2022.
South of Peridot, San Carlos Lake is a reservoir formed by Coolidge Dam and fed by the Gila River.
It is used to irrigate lands in and around the Gila River Indian Community. Water levels fluctuate dramatically depending on drought conditions and irrigation releases, and the lake has reportedly gone dry at least 20 times over the past century.
When full, it is among the largest of lakes in the state, with a capacity near 900,000 acre-feet. It’s become a fishing hotspot over the years; frequently stocked with game fish, it is what the San Carlos Apache Tribe refers to as a “fisherman’s paradise.”
But, by May 21 this year, the lake reached 0.04% capacity, or roughly 380 acre feet.
“About this time is when the high temperatures in the area rose above 100 degrees for prolonged days,” Juan said. “Dissolved oxygen levels were negatively impacted by the higher temperatures and ultimately lead to the onset of the fish kill for any remaining fish.”
The biggest difference between this year’s fish kill and the fish kill in 2022 is the difference in the fish — this year’s fish kill consisted primarily of game fish, whereas the fish kill in 2022 was 90% non-game fish species like carp and gizzard shad, Juan said.
Following the 2022 fish kill, by April 2023, the lake reached 62% capacity.
“We knew we were going to hold water for at least two years,” Juan said, so his department invested in game fish, stocking the lake with roughly 40,000 channel catfish, 20,000 largemouth bass and 20,000 black nose crappie.
“The population exploded with the new lake effect,” Juan said. “They were able just to thrive.”
“In two years, we had trophy fish,” he said.
However, by the winter of 2024, Juan and his team saw the water levels of the lake drop significantly.
“We anticipated some kind of fish kill coming to us spring or summer of 2026,” he said. “We lifted all bag limits around 2% so that anglers could harvest as many fish as possible.”
By this time, they were transferring the fish to other bodies of water in the area with the help of the U.S. Fish and Wildlife Service.
By the beginning of April this year, the department stated on its Facebook page that water levels had dropped to below 2%, with water levels decreasing at approximately 0.5% every 10 days. At that rate, they predicted a fish kill could occur by the end of the month. Days later the department lifted the bag limit on fish.
At that point, “we allowed anglers to harvest as many fish as possible,” Juan said.
Some tribal members walked away with 80 or 90 crappie by that point, he said.
On June 5, the department released a public notice on Facebook stating the closure of the lake, and that the decomposing fish posed potential health and safety hazards.
The lake’s recovery will depend on weather. Juan said a strong monsoon season could refill portions of the reservoir and allow the department to begin restocking fish.
“If we get 100 days of rain, it will last into the next fishing season,” Juan said. “Depending on how much water we get, we’ll stock accordingly.”
Comments
No comments on this item Please log in to comment by clicking here