Hundreds of fish are dead at Atascadero Lake, the latest occurrence in a string of summer issues there related to hot days and no rain.
City crews saw that the fish had died Friday morning and pulled out “a few hundred,” primarily small perch and large carp, Public Works Operations Manager Bob Joslin said.
“It’s something we can try to prevent, but with the high temperatures with the drought, it’s been tough,” City Manager Rachelle Rickard said.
Temperatures in the North County have consistently soared into the 90s and low 100s this summer.
The city is unable to add water to the lake because it’s cost prohibitive, officials said.
The die-off follows repeated challenges that have plagued the city-owned lake in previous years. The lake, which city officials liken more to a pond, is connected to Atascadero Creek, making it entirely dependent on rain.
In hot weather, algae blooms grow and decrease the water's oxygen, which can kill fish and plants. Hundreds of fish died in 2001 followed by about 30 dead fish in 2008.
City staff plans to remain at the lake through the weekend to clean up the fish and monitor the water’s oxygen levels. Staff also brought in three additional pumps “to move and aerate the water as much as we can to help the fish,” Joslin said.
Earlier this summer, other measures were taken when the city installed three floating fountains designed to produce more oxygen in the water when the lake reached about 40 percent capacity.
“With such a low water level and the heat, we knew we were getting close to a danger point,” he said.
Lake levels are now down more than 50 percent, the worst in nearly two decades. The deepest part of the lake is no more than 4 feet, Joslin said.
While the addition of the fountains didn’t stop the fish from dying, Rickard said had the city not installed them, the lake would have likely already seen one or two occurrences of dead fish this summer.
While the lake is low, it’s not as stinky as it was in July, Joslin said. The smell, associated with the exposed algae, has since dissipated because the algae have dried out.