The fish died Tuesday from what experts say was an apparent lack of oxygen. Crews worked around the clock and even began vacuuming the dead fish off the surface of the water.
Redondo Beach officials say cleanup crews and volunteers have scooped up some 35 tons of dead sardines from King Harbor and they expect to haul out another 30 tons well below the surface.
"You get them all scooped up and you move down from dock to dock to dock, and then you look behind you and they just floated out from underneath that dock you were just at," said Barry Ogle.
"They tell us there's 18 inches to 24 inches of fish still on the bottom," said Redondo Beach resident Bob Garde.
In some places, people could see 12 to 18 inches deep of dead fish. There simply weren't enough buckets to pick up all the fish.
For pelicans, it was an all-you-can-eat buffet. Mother Nature's cleanup crew was swallowing sardines down whole.
For crews cleaning up the dead fish, the task was a lot less enjoyable.
Eyewitness News captured a 360-degree view beneath the water by using an underwater camera aboard Bob Miestrell's yacht, the Body Glove.
The splash camera gave a view of the seafloor 12 feet under the water surface. Piles of fish were everywhere.
Biologists believe that predators scared the fish into Redondo Beach's King Harbor, and that's when the fish ran out of oxygen. Like too many fish in an aquarium, oxygen levels were just about zero, which led to the mess.
"It was really rough weather, strong winds, so they come in. There also may be predators out there chasing the schools of fish. They kind of bring them into the harbor. They swim inside the harbor where there they can feed and live happily," said Brent Scheiwe, program director of SEA Lab. "But unfortunately it's such a large number that swam into the back area where there is a limited amount of oxygen available to them."
"There are no signs of oil or chemicals or anything in the water that shouldn't be," said Andrew Hughan of the California Department of Fish and Game.
There is concern that if the fish are not removed quickly enough from down below, more will soon die.
"The bacteria from the decaying fish will soon start to again deplete the oxygen levels, and we don't want that to happen," said Redondo Beach Mayor Mike Gin.
Though the cleanup continues, there's still a long way to go.
"As long as they keep coming up, we'll keep scooping them up. Until then, we're not exactly sure how long it's going to take," said Steve Hyink with the Redondo Beach Fire Department.
The dead fish are being taken to a landfill to become fertilizer. Officials said the cleanup could take days and cost more than $100,000.
A Fish and Game official said the amount of dead fish in the harbor is equal to one day's catch of sardines for a fishing crew.
Longtime residents said they've never seen anything like this.
"I thought it was like some kind of epidemic of the sea life or, you know, something to do with 2012. It was kind of creepy at first," said Anthony Blada of Redondo Beach.
"I don't know how they're going to get rid of all those fish. It's just kind of scary and sad," said Manhattan Beach resident Sherri Walther.