SA bronze whaler shark sightings rise by four in 2021, but expert says there’s no need to worry

Four times as many bronze whaler sharks have been recorded off the SA coast so far in 2021 – so we asked an expert what it meant.

In popular fiction the shark expert desperately tries to warn reluctant authorities and beach goers of shark dangers before it is too late.

In a role reversal, Flinders University expert Professor Charlie Huveneers wants to reassure the public there is nothing sinister in four times as many “sightings” of bronze whaler sharks in SA this year.

Eighty-two bronze whaler sharks have been spotted in SA waters in the first six months of this year, compared with 35 in all of 2020. The rise is on target to be 4.6 times as many in 2021.

In the years prior to that there were 29, 27, 16, and 11.

Every shark sighting since 2006 is logged by the state government online.

White shark sightings are stable, but total shark sightings this year stand at 138 so far, compared with 82 for all of 2020, but Prof Huveneers said these were “sightings” only.

Prof Huveneers said rather than alarm, the message from the latest data up to June 15 was best described as “nothing to see here”.

A bronze whaler shark, seen during a shark tracking research study. Picture: Andrew Fox, Rodney Fox Shark Expeditions

A shark spotted near the Aldinga area by the Westpac Surf Life Saving helicopter. Picture Sarah Reed

“It highlights how shark sightings logs are meant to inform the public of recent shark sightings, not to infer trends,’’ he said.

“The shark sightings log should not be used to compare the number of sightings across years as it does not provide an accurate indication of trends.”

Sources of the information provided to the sighting log vary in accuracy, though they include experts from the White Sharks Count program, police officers, abalone divers, surf life savers and members of the public.

Bronze whaler sharks have not killed anyone in Australia since 2014 when Christine Armstrong, 63, was taken by a suspected bronze whaler as she lagged behind her daily swimming group at Tathra Beach, NSW.

But as recently as last week Jackson Bartlett, 10, was bitten on the foot by a suspected two-metre bronze whaler shark, about 75 metres from shore at Five Finger Reef in WA.

With eight fatalities last year, Australia was the deadliest location for all shark attacks in the world.

“Such bites (bronze whaler) are quite rare compared to other species, like white sharks, tiger sharks, bull sharks,’’ Prof Huveneers said.

“Number of sightings is heavily influenced and biased by how much effort is spent looking for sharks or number of people on the water, so eyes on the water.

“There have also been some concerns about the accuracy in species identification for some of the sightings.

“Even if the number of sighting accounting for effort was increasing, this might not reflect a change in shark population size but might be linked to sharks responding to environmental factors.”

A Department of Primary Industries spokeswoman said more than 160 species of sharks inhabited Australian waters, with five in South Australian waters considered potentially dangerous: the white shark, thresher shark, mako shark, bronze whaler and dusky shark.

She said if the sighting did not involve a triple-0 emergency, people could call the 24-hour FISHWATCH hotline on 1800 065 522, or via the SA Recreational Fishing Guide smartphone app.