Thousands of anchovies and other coastal fish, thought to be starved for oxygen in the ocean, washed up dead in the Marina del Rey harbor Sunday morning.

Scientists believe the unusual mass die-off, reminiscent of a near identical episode three years ago in Redondo Beach, was likely due to an algae bloom that depleted oxygen in the water or possibly the recent high surface temperatures.

Thousands of dead silvery fish laid along the rocks and floated to the surface alongside boats docked in Basin A near Via Marina and Bora Bora Way on Sunday morning and afternoon.

Danny Ericson, captain of sportfishing boat New Del Mar, said all the sardines in his on-deck bait tanks (which are kept full of sea water) died Saturday night. The crew would have to use frozen squid and lures to fish Sunday for barracuda, rock fish and other larger species, he said.

“They came into our bait receivers all dead,” Ericson said Sunday. “It’s pretty strange. Gotta be something with the oxygen levels in the harbor. There’s been lots of anchovies here lately and sometimes, with the heat, this happens. But this has been more than normal.”

Workers with the county Department of Beaches and Harbors cleared the four-smelling fish by the basketful.

It was not immediately clear whether the dead fish would be made into fertilizer, as tons of sardines were that died similarly in Redondo Beach’s King Harbor in March 2011. In that case, roughly 1 million dead sardines filled the harbor, resulting in a lengthy cleanup. The anchovies that died Sunday in Marina del Rey numbered in the thousands.

The Redondo Beach sardine die-off is believed to have been caused by an algae bloom that depleted oxygen inside the breakwater. Scientists working with Heal the Bay and L.A. Waterkeeper believe this die-off is probably also due to an algae bloom.

Officials with the California Department of Fish and Wildlife were not available for comment Sunday.

Rachelle Magness, who recently moved to Marina del Rey, followed groups of happy pelicans and sea gulls to the harbor on Sunday afternoon. There, she saw the masses of dead fish floating on the surface.

“It’s so crazy,” Magness said. “I was going to go out on my paddle board but it’s kinda scary.”