Sea Hare deaths in Augusta

Attention dog owners

Recently, approximately 300 – 700 dead sea hares have washed ashore along Augusta beaches and lower parts of the Hardy Inlet, including Jays Beach (dog exercise area), the Colourpatch and Ellis Street Jetty. These slug-like creatures pose a serious threat to dogs, potentially causing seizures, vomiting and even death if ingested or if the dog comes into contact with their toxic slime or ink.

What are Sea Hares? 

Sea hares (Aplysia gigantea) are a type of large sea slug, often found in intertidal areas and seagrass beds.

Why have the Sea Hares washed ashore?

Sea hares have washed ashore before in the Hardy Inlet – this seems to be a regular event that often occurs in late summer. It is believed that the cause is related to weather conditions, particularly strong south-easterly winds, that have coincided with life cycle behaviours of the sea hares, where they have washed onto the beach and died.
There have been occurrences of very high levels of mortality, with the last one in Augusta being in 2021 when thousands of animals washed ashore over several days. 

Why are they dangerous to dogs? 

These creatures carry toxins, and even a small lick or contact with their slime or purple ink can be harmful to dogs.

Symptoms of Sea Hare poisoning in dogs:

• Tremors and seizures.
• Vomiting.
• Excessive drooling.
• Muscle weakness or spasms.
• Difficulty walking.
• Over-excitement.
• In some cases, death.

What to do if you suspect your dog has been exposed:

• Seek immediate veterinary attention.
• Contact the Animal Poisons Helpline for advice (1300 869 738 in Australia).

Prevention:

• Keep dogs on a leash at the beach.
• Supervise your dog closely, especially around seaweed and the shoreline.
• Be vigilant and aware of sea hares washing up on the beach.

Where to find more information:

• Animal Poisons Helpline
• ABC News article 

Signs have been installed at key public areas to warn dog owners of the risk of toxicity for dogs. Like in previous years, it is possible that the mass mortality was caused by weather conditions that washed the animals ashore where they died. There are also visible Trichodesmium (algae) blooms in the estuary, but these are a natural occurrence and unlikely to be related to the mortality of sea hares.

The incident has been reported to the Department of Primary Industries and Regional Development (DPIRD) and Department of Water and Environmental Regulation (DWER). The beaches will be monitored over the coming days.