Toxic algae blooms detected on NSW coastline

21 Oct 2022

The NSW Department of Primary Industries (DPI) advises people not to consume shellfish (including bivalves, crustaceans and gastropods) collected or caught in Broken Bay and Twofold Bay due to a localised outbreak of toxic algae bloom, at the risk of Paralytic Shellfish Poisoning (PSP).

Recreationally harvested shellfish should not be eaten because the algal toxins are harmful to humans. Blooms can be more frequent in spring and summer and are exacerbated by adverse weather. Deputy Director General for Biosecurity and Food Safety John Tracey said the current affected area includes the waters of the Hawkesbury River downstream of the Brooklyn railway bridge and Brisbane Water downstream of the Rip Bridge. A separate bloom has also been detected in Twofold Bay (Eden) on the far south coast of NSW, however, the full extent of the blooms may extend beyond these locations.

“Paralytic shellfish toxins are produced by certain toxic algae species and shellfish such as oysters, mussels, scallops, cockles and clams should not be taken or consumed from this area,” Dr Tracey said.

“Cooking the product does not remove the risks posed by this toxin.

“Lobsters and abalone are known to accumulate the toxin in the viscera (internal organs) of rock lobsters and the viscera and mantle (frilly fringe) of abalone.

“It is recommended that consumption of viscera from crustaceans and gastropods captured from Broken Bay and Twofold Bay is avoided.

“The mantle of abalone should either be removed or scrubbed clean to remove any pigment.”

Dr Tracey said symptoms usually appear within 10 minutes to 3 hours of eating. Symptoms may include:

numbness and a tingling (prickly feeling) around the mouth, face, and extremities (hands and feet)
difficulty swallowing or breathing
dizziness and headache
nausea and vomiting
paralysis and respiratory failure and in severe cases, death.
“Anyone experiencing these symptoms after eating seafood from or near the affected area should seek immediate medical attention,” Dr Tracey said.

“Paralytic Shellfish Poisoning is rare, but it is important that people follow this advice to avoid getting sick.

“Seafood in shops and restaurants is safe to eat because the NSW Food Authority monitors the safety of commercially harvested shellfish.”

Algal blooms can occur anywhere along the coast and are normally the result of the surge of nutrient rich deep ocean water onto the continental shelf and can often be seen after rainfall events in estuaries and in river mouths. Some of these algae produce harmful toxins that can build up in marine shellfish.

For more information please visit the NSW Food Authority for more information on Recreational harvesting of seafood, please visit

Media contact: 02 6391 3686