Mass Fish Die-Off Forces Indefinite Closure of Popular California Lake

Hundreds of thousands of dead fish are washing up on the shores of Lake San Antonio in Monterey County, California, prompting officials to close the popular fishing destination indefinitely.

The die-off, which began on July 4, initially affected bait fish but has since spread to larger species like catfish, bass, and trout. Bryan Flores, chief of parks in Monterey County, called it the largest fish die-off the county has ever seen.

"It seems like every fish species in the lake is being impacted," Flores said. "We have never seen this type of multi-species die-off, especially on this scale."

The county decided to close the artificial lake on Tuesday, ordering campers to leave by Wednesday morning. Officials cited concerns about water safety and the health hazard posed by decaying fish on the beaches.

The cause of the die-off remains unclear. Flores noted that living fish are exhibiting "odd behavior," which could indicate algae growth or low oxygen levels caused by the recent heat wave. The California Department of Fish and Wildlife is conducting tests to determine the cause.

Lake San Antonio, a 350,000 acre-foot reservoir built in 1965, is known for its abundance of fish and has long been a prime spot for fishing enthusiasts. The closure is expected to last at least through next week, with the full cleanup anticipated to take several weeks.

Despite the massive scale of the die-off, Flores said it shouldn't be harmful to humans or other animals. No deaths have been observed among animals feeding on the dead fish.

The incident highlights the delicate balance of aquatic ecosystems and the potential impacts of environmental factors on fish populations. As climate change continues to affect water temperatures and conditions, such events may become more common, underscoring the importance of conservation efforts and environmental monitoring.