In Ventura County, a mass of sardines that crowded into the harbor has died. The harbormaster found the dead fish on Monday after about 1,000 sardines turned up near the shopping center at Ventura Harbor's south end.
Live sardines had crowded the area for a week and harbor officials lowered aerators into the water — just like aquarium keepers might pump in air — with the aim of saving some sardines.
Observers say the fish looked as if they ran out of oxygen. Volunteers skimmed up 6 tons of fish in Ventura so far, and if this story sounds familiar, it's because early last month about 175 tons of sardines turned up dead in King Harbor in Redondo Beach.
USC biologists who tested the King Harbor fish found domoic acid, a poison some algae produce. Researchers are examining whether exposure to a harmful algal bloom contributed to the fish kill in Redondo.
State fish and game officials say some fish die-offs are normal — rough water or predators can chase fish into a harbor, or low-oxygen water can well up naturally from the deep. Scientists and state officials are working to explain both events.