ABC Top Stories58 minutes agoEnvironment2 min readAustralia

Toxic sea hares wash up on NSW beach, posing threat to pets

Quick Look

Thousands of toxic sea hares have washed ashore at Aslings Beach in Eden, NSW, linked to a natural algal bloom.
Marine biologist Culum Brown warns the slugs can retain toxins harmful to dogs if ingested, prompting council cleanup efforts and pet owner advisories to avoid contact and wash hands after handling.

AI-generated summary

Why It Matters

Sea hares, a type of sea slug, have begun washing up at Aslings Beach in Eden, NSW, coinciding with a natural algal bloom. These organisms feed on algae and can retain toxins from certain algae as a defense mechanism.

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Thousands of toxic jellies have been washed up at a popular beach on the NSW far south coast, triggering curiosity and a warning to pet owners.

Sea hares, which are a type of sea slug, began washing up at Aslings Beach at Eden a week ago.

Macquarie University marine biologist Culum Brown said it was no coincidence they arrived alongside a naturally occurring algal bloom.

"They graze on algae," he said.

"The danger here is that some of the algae they eat contain various toxins which the slug can maintain and use as a predator defence."

High tides caused many of the toxic sea hares to disperse back into the water.

The Bega Valley Shire Council also organised local contractors to remove them from the beach.

However, some still remain in patches along the shore, causing intrigue among beach goers.

"When they're underwater, they have protrusions that look a bit like the ears of a rabbit or a hare," Professor Brown said.

Toxic and slimy

The algae itself was identified by the Bega Valley Shire Council (BVSC) as a mix of red macroalgae native to south-eastern Australia and non-toxic.

But sea hares feeding on the algae can pose a serious risk to dogs if they lick, mouth or ingest them.

Pet owners visiting the beach are advised to keep a distance.

“Council crews removed thousands of sea hares from Aslings Beach last week," BVSC sustainability manager Derek Van Bracht said.

"The volume of sea hares on the beach has since reduced, however a visible algal bloom remains offshore.

"So dog owners are advised to stay vigilant when walking their pets in the area."

Professor Brown said although sea hares were a bit "odd looking", it was not unusual to see them wash ashore in large numbers on the southern-Australian coastline.

He said their arrival usually coincided with rough seas and strong on-shore winds.

Professor Brown said while sea hares were not dangerous to humans, precautions should still be taken.

"If you do handle them, you should definitely wash your hands," he said.

"Don't touch your eyes, because they can cause irritation."

What to Watch

AI outlook — possibilities, not facts

Local contractors will continue removing sea hares from Aslings Beach as needed
Likely · Within days
Pet owners will be advised to remain vigilant when walking dogs near the shore
Very likely · Within weeks

Open Questions

How long will the algal bloom persist offshore?
Are there any long-term ecological impacts from the sea hare accumulation?
What specific toxins are present in the algae consumed by the sea hares?

Toxic sea hares wash up on NSW beach, posing threat to pets

Quick Look

Thousands of toxic sea hares have washed ashore at Aslings Beach in Eden, NSW, linked to a natural algal bloom.
Marine biologist Culum Brown warns the slugs can retain toxins harmful to dogs if ingested, prompting council cleanup efforts and pet owner advisories to avoid contact and wash hands after handling.