“Worst case, this thing continues, and we just don’t have a season," said Bitts, who makes about half his income off Dungeness crabs, the most common type of crab harvested off the California coast. "That would be a very serious deal indeed.”

Consumers might be annoyed that a favorite seafood will be more scarce, and those who make their living from it are rightly worried about a major financial loss. California’s crabbing industry brings in around $60 million a year for harvesters alone, and the revenues amount to much more when counting the grocery stores and restaurants who sell the catch.

An even more dire concern may be that the contamination of crabs points to the Pacific Ocean facing problems of a magnitude never seen before.

Persistent warm-water conditions along the U.S. West Coast have contributed to the largest toxic algae bloom ever recorded. One type of algae — Pseudo-nitzschia — has poisoned much of the food web, and is drastically affecting marine ecosystems along the West Coast. One sign of that is that sea lions suffering from seizures caused by domoic acid have been washing up on California beaches.

The algae bloom now in the Pacific stretches well beyond state borders, from the Channel Islands off the coast of Santa Barbara to the Aleutian Islands in Alaska. One irregularly warm area of the ocean has been joined by El Niño, a cyclical weather pattern characterized by warm ocean water.

“This is usually the time of year when we expect an algae bloom to dissipate, because typically the water is cooling off,” said Michael Milstein, a public affairs officer at the National Oceanic and Atmospheric Administration (NOAA). “But in this case it doesn’t seem to be tapering off as we would have expected, and that’s in large part because the ocean is still quite warm.”

The persistently warm water and poisonous algae have prompted seafood harvest bans up and down the Pacific Coast, affecting California, Oregon and Washington.

Larry Collins, president of the San Francisco Bay Crab Boat Association, said, “I’ve seen the crabs delayed in Oregon and Washington many times from domoic acid before. What’s unusual is that it’s never happened to us down here.”

California’s delaying the season for crabs is only one of a series of such delays or suspensions since May in fishing for anchovies, shellfish and Dungeness crabs in the Pacific, said Raphael Kudela, a professor of ocean sciences at University of California, Santa Cruz.

“The toxin [domoic acid] has been around so long it’s associated with mortalities of seabirds, of sea lions," he said. "The toxin is working its way through the food web."

Shellfish and anchovies, among others, feed on the toxic algae and are in turn eaten by larger animals, spreading domoic acid up the food chain.

The Marine Mammal Center reported that as of early September it had rescued 180 sea lions, three-quarters of which were suffering from the effects of domoic acid, which can include lethargy, disorientation, seizures and death.

The Pacific’s warmer temperatures pose another danger to sea lions by driving fish they feed on to colder waters. The NOAA has deemed this threat serious enough to declare it an “unusual mortality event.”

On Friday, the federal agency co-sponsored a congressional hearing in Washington, D.C., on the toxic algae bloom. Participants at the event described the impact on West Coast ecosystems and fisheries.

Some experts have said that delaying crabbing season to protect consumers won't address the causes of the algae bloom.

“If you just protect the people, that’s great," said William Cochlan, a senior research scientist at San Francisco State University who studies phytoplankton. "But if you don’t do the research, or our agencies don’t fund scientists to do this sort of research, we’re essentially just sticking our heads in the sand. And there’s no reason to think it’s going to go away."

Bitts, the fisherman who relies heavily on Dungeness crabs and is based in Eureka on the Northern California coast, is hoping for the best.

“This has been a very strange year on the ocean, in ways that I don’t understand,” said Bitts, who captains a fishing boat called the Elmarue. “If you’re a fisherman, you have to put some aside in the good years and hope it’s enough to get you through the bad years.”