Updated

The government warned consumers Monday not to eat the soft, green substance found in the body cavity of lobsters, saying it may be contaminated with a toxin.

It's still OK to eat the white lobster meat found in the claws and tails of the undersea delicacy, but the green stuff that most diners already avoid should definitely be discarded this year, said the Food and Drug Administration. Known also as tomalley, the substance acts as the liver and pancreas of the lobster.

A red tide — or algae bloom — ranging from Northern New England to Canada this year has contaminated fishing grounds with high levels of toxins that cause paralytic shellfish poisoning. The federal warning follows similar advisories from public health authorities in Maine, Massachusetts, New Hampshire and Canada.

The warning applies to American lobster, also known as Maine lobster, which is harvested in Atlantic waters from Canada to South Carolina.

Cooking does not eliminate the toxins, but studies have shown that even when high levels are present in the tomalley, lobster meat is usually not affected, the FDA said.

Symptoms of paralytic shell fish poisoning usually appear within two hours of exposure. They include tingling and numbness of the mouth, face or neck, muscle weakness, headache and nausea. Anyone who suffers such symptoms should see a doctor, the FDA said. In rare cases, people who consume a large amount of toxin can suffer respiratory failure and death.