Dead dolphin and sharks found on South Australian beaches as toxic algal bloom crisis rages on

A grim discovery on an SA beach this week proves the toxic bloom crisis is far from over, despite hopes the arrival of bioluminescent algae could turn the tide.

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A dead dolphin and at least 10 sharks have washed up on SA beaches this week – a grim sign the toxic bloom crisis is far from over, despite hopes the arrival of bioluminescent algae could turn the tide.

The juvenile common dolphin, bloodied and lifeless, was discovered on Carrickalinga Beach on Thursday by local woman Amber, who made the confronting find during a walk.

Photos shared by Shark Watch South Australia show the dolphin lying on the sand with blood around its mouth – another heartbreaking addition to what the group has described as a “relentless” tide of dead marine life now appearing along the coastline.

“Please report your findings to the iNaturalist group and PIRSA Fishwatch,” the group urged followers.

Dead Dolphin calf on Carrickalinga Beach Picture: Amber Rizz

Port Jackson shark on Largs Bay on July 11. Picture: iNaturalist/aborgas

The grim discovery comes just three days after scientists and fishers reported sightings of Noctiluca scintillans — also known as ‘sea sparkles’ or ‘red tide’ — along the south coast.

It is known to feed on Karenia mikimotoi, the toxic algae species responsible for months of marine life deaths across South Australia.

Its appearance sparked cautious optimism that nature might be fighting back, but experts warn it’s far too soon to call it a solution.

The growing number of carcasses still appearing along SA’s shores may be proof of that.

This week alone, at least nine sharks have been reported dead by locals using the iNaturalist app, including multiple Port Jackson sharks found at Maslin Beach, Kingston Park, Tennyson, Port Noarlunga and Largs Bay. Gulf and Cobbler Wobbegong sharks have also been reported at Hallett Cove, Corny Point, Seacliff and Glenelg North.

A Port Jackson shark found dead at Tennyson on July 9. Picture: iNaturalist/sunset_chaser

Another Port Jackson shark also washed ashore at Maslin Beach on July 5. Picture: iNaturalist/jepdidnot

A dead shark was also seen floating in shallow water off Boston Bay near Port Lincoln on Thursday, bringing this week’s total to at least 10.

Among those helping to track the growing body count is Andy Burnell from Crab.e.cam, who found at least 100 dead bluefin leatherjackets, along with Shaw’s cowfish and globefish, washed up on Tennyson Beach during a Thursday morning walk.

“It is not fun, but I feel like I’m doing something and they are being recorded,” he wrote.

“The iNaturalist site or phone app are easy to use once you’ve worked it out. I like that it is a record for me too and helps me identify things I don’t know. Give it a go if you are walking our shores!”

Last week, more than 20 Cobbler Wobbegongs and a Port Jackson shark were found rotting along Tumby Bay beach.

Port Jackson shark at Kingston Park on July 5. Picture: iNaturalist/adelaidecrows35

Mass fish kills have been reported across the Fleurieu Peninsula, Yorke Peninsula and Adelaide’s metro coastline, with stunned locals describing the scale of the damage as unlike anything they’ve seen before.

It comes as the Greens urge the federal government to declare the bloom a national disaster because of its impact on coastal communities and businesses.