A toxic menace is lurking off the shores of California and it's brought the state's $60 million commercial crab industry to a grinding halt.

The California Department of Fish and Wildlife (CDFW) announced an immediate delay of the commercial crab season because Dungeness crabs have become too toxic for human consumption. The ruling came just a day after California's Fish and Game Commission delayed the start of the recreational Dungeness crab season and closed the northern part of recreational rock crab fisheries in California, citing concerns with neurotoxin levels found in the crabs.

"Crab is an important part of California's culture and economy, and I did not make this decision lightly," CDFW Director Charlton H. Bonham said in a statement. "But doing everything we can to limit the risk to public health has to take precedence."

The department has prohibited any commercial fishing and possession of Dungeness and rock crabs from ocean waters north of the Ventura-Santa Barbara county line. The fisheries will reopen once agencies have determined that the level of toxins has diminished.

The recreational crab season was scheduled to begin November 7th and the commercial rock crab season was scheduled to begin November 15.

"We're working out a process to make sure that we do everything we can to reopen the fisheries once the advisories are lifted," said Jordan Traverso, a CDFW spokeswoman.

According to the state Office of Environmental Health Hazard Assessment, Dungeness and rock crabs from California's north coast have been found with hazardous levels of domoic acid, a neurotoxin. The memo noted that a significant portion of the crabs were found to have toxins exceeding regulatory levels of 20 parts per million (ppm), with one crab containing more than 100 ppm.

Domoic acid poisoning can cause vomiting, diarrhea, dizziness, and, in severe cases, death.

In a health advisory issued November 3, California's Department of Public Health urged residents not to consume any Dungeness and rock crabs caught between the Oregon border and the southern Santa Barbara County line.

"The levels have exceeded the State's action level for the crabs' body meat as well as the viscera, commonly referred to as crab butter, and therefore pose a significant risk to the public if they are consumed," the department said in its statement.

Although the industry's annual income is at risk of being lost with a prolonged closure of the fisheries, Dave Bitts, president of the Pacific Coast Federation of Fishermen's Associations, told the Sacramento Bee that everyone agreed that crabbing should not continue.

"This particular toxin is something we seriously do not want to mess with," he said.

Mark Gorelnik, chairman of the Coast Side Fishing Club, an all-volunteer recreational fishing organization, says that he doesn't know anyone who has objected to the closure so far.

"Dungenness crab fishing is an important cultural activity in San Francisco, but it shouldn't be done at the expense of anyone getting sick," Gorelnik said. "Right now we're just concerned about how quickly the state will announce the fisheries reopening. That's the million dollar question."

Gorelnik hopes that the recreational crab season will reopen by mid to late November.

State agencies say that the rise in the domoic acid levels are due to a persistent algae bloom in the Pacific Ocean, likely caused by warmer temperatures from El Niño.

It will be difficult to measure the impact of the delays, says Rod Moore, a senior policy advisor to the West Coast Seafood Processors Association.

"It's going to depend on how long the season is closed in California," Moore said, noting that one- or two-week-long delays are not unusual in the crab industry. "If the fishery goes away completely, then that's a problem."

Moore said Oregon was still testing its crab and would likely have time to prepare for a delay. He emphasized that crab found in restaurants should be safe to eat, as the current stock comes from an earlier season. Oregon's commercial crab season does not begin until December.

In Washington, the state's Department of Fish and Wildlife also closed one of its recreational crab fishing bays last week because of high domoic acid levels.