Warning: This story contains images that may distress some readers.

The deaths of more than 50 little penguins along South Australia’s south coast in recent months are being investigated by environment authorities, after more than two dozen carcasses reportedly washed up at a beach over the weekend.

Flinders University researcher and volunteer Stephen Hedges told ABC Radio Adelaide a member of the public yesterday reported seeing about 30 dead penguins at Goolwa.

He said the most recent deaths have been reported to the Department for Environment and Water, but the situation’s underlying causes were unknown.

“It seemed to have been going on for a while but yesterday was awful,” Mr Hedges said.

A dead penguin found on SA’s south coast beaches in recent weeks.(Supplied: Lindy Downing)

Mr Hedges, who has been recording penguin deaths near the Murray Mouth, said there were usually two or three deaths a month after each breeding season, which ends around late summer.

But the researcher — who also volunteers at Granite Island, which has long been home to a little penguin colony — said he had been getting calls reporting a new dead penguin every couple of days.

“We had about 11 dead in February … 14 in March, 13 in April, and it was just daily almost that I’d get a call. We’re up to nearly 57 so far this year,” he said.

“The really sad news yesterday was we got a call … to say there were up to 30 birds washing around on the beach at Goolwa.

“We haven’t seen a bird come back to Granite Island this week from the sea.”

Stephen Hedges has spent more than 20 years observing and researching Granite Island’s little penguins.(ABC News: Caroline Horn)

Mr Hedges said he was now “nervous” the entire Granite Island colony could come under threat.

“Last census we had 30 birds live on Granite Island and we had a good breeding season, they actually popped out 27 chicks,” he said.

In February, volunteers urged visitors to the island to shut the causeway’s gate, fearing the struggling penguin population could be wiped out by a fox in a single night.

Mr Hedges said the number of penguins had “picked up” after nine birds were killed in a fox attack in 2020.

A spokesperson for the Department of Environment and Water said National Parks and Wildlife Service staff visited Goolwa Beach and retrieved some of the penguin carcasses for testing.

“[The] cause of the penguin deaths is unknown, but carcasses tested earlier in the year showed no signs of notifiable diseases,” they said.

“Potential causes of death could also include fatigue, weather events such as storms, or penguins being attacked at sea by other animals.”

They said penguin deaths were “not uncommon”, with dozens of reported penguin deaths on the Fleurieu Peninsula coast every year.

These penguins had likely travelled from other areas to feed in South Australian waters, they said.

Blue-green algae could be to blame

Mr Hedges said most of the dead penguins that had been found were a healthy size.

Some of the carcasses showed clear evidence of injury — but it is unclear if those injuries were only inflicted after the animals had died.

“Most of them are whole birds which showed something internal,” Mr Hedges said.

“The one in front of me is …1.2 kilograms.

“Years ago when we had a lot that died, they were all under a kilo — 700 grams — so it seemed like they were starving.”

A dead little penguin found on Goolwa Beach over the weekend.(Supplied: Lindy Downing)

Mr Hedges said he and the department have been collecting feathers from the carcasses this year for testing.

He said one of the possible causes of death was blue-green algae.

SA Health issued a warning in March for people to avoid contact with River Murray water between Wellington to Goolwa after it detected elevated levels of the algae.

“Blue-green algae is almost invisible and if you think where penguins are on the food chain, if they’re eating little creatures up to pilchards, they’re concentrating the toxins,” Mr Hedges said.

Testing to find the cause of death may take a while, Mr Hedges said.

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