Thousands of highly toxic sea hares have washed up on a beach along the NSW South Coast.
Dog owners are warned to keep their pets away from Aslings Beach at Eden after algae and the potentially deadly creatures covered the shoreline last week.
The algae was identified as a mix of non-toxic red macroalgae native to southeastern Australia and highly toxic sea hares that feed on them.
A Bega Valley Shire Council spokesman said blooms of marine macroalgea were a common occurrence in spring caused by natural processes.
“However, the sea hares feeding on the macroalgae can pose a serious risk to dogs if they lick, mouth or ingest them,” a spokesman said.
The Australian Poisons Helpline advised sea hares or sea slugs were marine gastropods that could be life-threatening when they came into contact with animals.
They are found swimming or gliding across rocks, small pools and sea grass and are commonly found in large numbers in shallow waters during summer.
“Dogs can be severely poisoned by mouthing or ingesting beached sea hares,” a spokesman stated on the poisons website.
The council organised contractors to remove the sea hares from the beach and installed signage to warn beachgoers.
Dog owners were warned to avoid the area to prevent coming into contact with the sea hares and to contact a veterinarian immediately if their pets were exposed to the deadly creatures.
“Sea hares are marine animals that feed on algae and can sometimes wash ashore in large numbers when conditions are favourable,” a spokesman said.
“Their presence is associated with the current natural algal bloom at Aslings Beach.”