Director of Public Health Dr Mark Veitch said eating wild shellfish from the region could cause serious illness.

“Do not collect and eat wild shellfish from this region,” he said.

”Harmful algal blooms are present in these waters. Shellfish feed on algae and concentrate the algal toxins in their flesh.

“Toxins in shellfish are not destroyed by cooking or freezing.”

Dr Veitch said an earlier alert for the coast and estuaries from Coles Bay to the northern tip of Maria Island was still current.

“Very high levels of paralytic shellfish toxin have been found in shellfish from Great Swanport and Great Oyster Bay to Little Swanport.

“Wild shellfish from this area have caused illness during previous harmful algal blooms.”

Low levels of toxins have also been detected in recent weeks in shellfish from as far south as Bruny Island, so wild shellfish from anywhere along the East Coast may pose a risk, Dr Veitch said.

Symptoms of shellfish poisoning can occur within minutes to hours after eating shellfish.

Shellfish poisoning symptoms can include:

People should seek urgent medical attention if they experience any of those symptoms after eating wild shellfish, Dr Veitch said.

“Oysters, mussels, clams, pipis, wedge shells, abalone, scallop roe and the intestines and livers of rock lobster could be affected.

“Shellfish for sale in shops and restaurants is safe to eat because the safety of commercially grown shellfish is closely monitored.

“A number of commercial shellfish leases have been closed to harvest because of the harmful algal bloom."