ABC South West WA

Topic: Animals

Tuesday, June 30, 2026, at 5:21 pm

Many whales migrate north along Australia's west coast each year to give birth in warmer waters.

In short:

The number of whales seen along Western Australia's south coast is 60% lower than in previous years.

The decline is unexpected, and the cause is unknown. It might be due to a lack of food or a disease like bird flu.

What's next:

Marine scientists want authorities to investigate further by testing dead whales that have washed up.

The number of whales spotted along Western Australia's coast has fallen by 60%, and scientists are trying to find out why.

Western Australia's coastline is an important migration route for several whale species, including humpbacks.

In a recent whale count, scientists saw only 22 humpback whales, compared to 69 and 62 in the previous two years.

The chair of the Geographe Marine Research group said the low numbers are unusual and not expected.

The annual whale count took place on June 28.

The researcher said she wouldn't expect food availability to account for such a big drop in whale numbers.

The Department of Biodiversity, Conservation, and Attractions said it wasn't aware of any significant decrease in humpback whale activity.

The department said the timing of the whale migration can change each year, and the number of whales seen can vary.

Decline 'never seen' before

A whale-watching operator said this year's whale numbers are the lowest he's seen in 17 years.

His staff counted 32 whales, down from 93 last year.

The operator said he's never seen the numbers in Flinders Bay as low as they are this season.

Paul Cross says this season's whale numbers have been unusually low.

The operator doubts that the usual reasons for reduced numbers are the sole cause of the drop-off.

He said the whales they've seen don't seem happy, and something is causing that.

Multiple whale-watching operators have reported very low whale numbers this season.

Scientists want investigation

The research group thinks the bird flu might be behind the declining whale numbers.

The group said limited food in Antarctica and late migration could also be contributing factors.

There have been cases of bird flu in migratory seabirds on Western Australia's south coast.

Australian authorities say there's no evidence of mass deaths or the disease spreading to other birds or mammals.

The same strain of bird flu has caused many deaths among southern elephant seal pups on Heard Island.

Whale researchers are discussing the migration and the possible causes of the decline.

The researcher said unverified theories of bird flu transmission in humpbacks need to be investigated.

She said whales have been seen exhibiting 'worrying behavior' along the Western Australian coastline.

There's a southern right whale in a bay, which is unusual, and it seems disoriented.

The researcher said whales are in close quarters with potentially infected seabirds near Antarctica.

A marine scientist said bird flu is a legitimate concern for whale populations.

The scientist said we know these animals face many pressures, both human and natural.

Bird flu is a global issue, and these whales migrate to areas where bird flu has been found.

Marine scientists think the decline could be due to several causes, including food and bird flu.

Tuesday, June 30, 2026, at 5:21 pm

See more ABC coverage in your search results

Promotion

Practice Listening