SANTA CRUZ (CBS/AP) — Workers continue to clean up Santa Cruz Small Craft Harbor Saturday after thousands of anchovies swarmed into the harbor and died in the water.

Acting harbormaster John Haynes said at least 30 tons of fish have been scooped out of the water since Wednesday night’s die-off.

The fish kill is the third in many weeks along the Santa Cruz County coastline. Thousands of anchovies washed ashore in Capitola on July 25 and a similar number of white croakers lined Manresa State Beach on July 18.

Raphel Kudela, professor of ocean sciences at UC Santa Cruz, said the fish kills are likely the result of predators pushing the schools to shallow water with limited oxygen supply.