Tens of thousands of fish that washed up in a Southern California harbor died because of a lack of oxygen, state wildlife officials concluded Monday afternoon.
Marine life experts told NBC4 it's possible that warm weather led to algae blooms, which limited the amount of oxygen available to the fish when they swarmed into Marina del Rey. The die-off began Saturday and created a powerful stench in the coastal community as a blanket of anchovies, angel sharks and rays coated the water.
State wildlife officials said the die-offs are "not uncommon and can happen for a variety of reasons."
An estimated 70,000 fish ended up in the seaside community about six miles north of Los Angeles International Airport. Crews using front-end loaders and about 300 trash bags holding about 45 pounds of apiece removed fish from the water. Other fish were scooped up by sea birds that flocked to the harbor for an easy meal.
As for the odor, that's expected to linger for days.
"It is likely there is something in the water," said Carol Baker of the LA County Department of Beaches and Harbors. "It's a little bit too early to tell (what it is). We need to continue to watch what happens over the next few days. The situation may not be over."
Jennifer Goodwin, who lives there, said she isn't going paddleboarding anytime soon.
"The water's just filthy," she said.
By Monday morning, most of the fish (pictured, right) had collected in boat slips and a corner of the marina.
"For the next couple of days, I imagine it could be a little unsightly and there still could be some odor associated with this," said Matthew King, of the nonprofit environmental group Heal the Bay. "Warmer temperatures can create algae blooms, which will suck up a lot of oxygen. That's happened in the past, and hot weather always has been associated with low oxygen levels in the water."
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Last week marked the warmest week of the year in Southern California, where temperatures climbed into the 90s and 100s.
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The smaller fish might have ended up in the harbor when they tried to avoid becoming a food source for larger fish near shore. The sea walls of the marina create a confined space with reduced oxygen levels, said bait expert Mike Spears
"It was a low tide, which means the water was going out, nothing was coming in from the ocean, so it was just stale water and they just suffocated in it, and everything around them suffocated, too," Spears said.
Low oxygen levels also likely caused a large fish kill in a Redondo Beach harbor in March 2011.
The sardines and other fish likely wound up in King Harbor after seeking shelter from rough seas.
Gordon Tokumatsu contributed to this report.