Rapid succession of giant sunfish deaths leave scientists 'lost for words'

An 'excellent mystery' is how one marine biologist has branded the strange occurrence.

EXCLUSIVE: Rare giant sunfish have been washing up on Australia’s coast at a rate that’s left a leading expert “lost for words”.

The decaying creatures are hard to miss as their flat disc-like bodies often span close to four metres long. Yahoo first became aware of the spate of deaths after curious beachgoers began posting images to social media a week ago.

A total of four bodies, believed to be the Mola alexandrini species, have been documented between October 28 and November 22. And while that may not seem like many, seeing one in a single year can be unusual.

A person standing over a sunfish at Jervis Bay.
A fourth sunfish was spotted at Jervis Bay. Source: iNaturalist/brinarra

Expert 'surprised' after four rare sunfish strandings

Danish marine biologist Dr Marianne Nyegaard told Yahoo News Australia the “rapid succession” of strandings was “an excellent mystery”. “There’s nothing like it in my records,” she added.

Nyegaard, who has expertise in southern hemisphere sunfish, said although live individuals are often seen in NSW, stranding observations are “rare”. There were five spaced out in the years 2021 and 2022, and three in the years 2002 and 2003, but then she doesn’t have a single record until 1954.

“Of course I don’t know of all standings but this pattern was nevertheless a bit of a surprise when I added up the numbers,” she added.

A decayed sunfish at Broulee in the sand.
A Yahoo reader sent in a report of a third sunfish, this time at Broulee. Source: Geoff Berry
Judith poses next to the Warilla Beach sunfish (left). Another dead at Sussex Inlet (Right).
A woman poses next to the Warilla Beach sunfish (left) which was found days after one was photographed dead at Sussex Inlet (right). Source: Judith Merchant/Brooklyn Jade

Details of four rare sunfish revealed

  • Broulee on October 28 or 29.

  • Sussex Inlet on November 12.

  • Warilla Beach on November 15.

  • Jervis Bay on November 22.

Yahoo News Australia first reported on two standings a week ago at Warilla Beach and Sussex Inlet on the south coast of NSW, prompting a reader to alert us to a third body.

Geoff Berry photographed that animal at Broulee, 20km south of Batemans Bay, on November 4, but locals began reporting it on the weekend of October 28.

The fourth fatal stranding occurred at Jervis Bay November 22. Records of this fish were spotted by Nyegaard on iNaturalist, a social network used for sharing observations about wildlife and plants.

She encourages anyone with information about beached sunfish to report them on iNaturalist, or to the Australian Museum or Auckland Museum.

The Australian Fisheries Management Authority told Yahoo it was not able to provide any insights as to what may have led to the recent strandings.

Love Australia's weird and wonderful environment? Get our new weekly newsletter showcasing the week’s best stories.

Banner reads 'What on Earth' with 'Subscribe to our new weekly newsletter' and a collage of images of australian natural wildlife.
Click here to sign up to our newsletter.