Call for greater protection for Whyalla’s giant Australian cuttlefish population rebuffed amid low catch numbers

Fishing bans worked once and there’s a call to bring them back after an alarming plunge in giant cuttlefish numbers this year.

There is a call to reinstate a fishing ban in the northern Spencer Gulf after a steep drop in the numbers of giant Australian cuttlefish.

This year’s annual cuttlefish count, conducted by the South Australian Research and Development Institute (SARDI), found 107,000 animals at Whyalla during the breeding season, less than half of 2020’s record count – there were 250,000 last year.

But the government has described this year’s count as a “healthy tally” – higher than the average over the past decade and much better than the count of 13,000 recorded in 2013.

It said fishing outside a protected zone has negligible effect on the animals’ population and other factors, such as water temperatures and fluctuations in food, have larger influence.

A giant Australian cuttlefish during the aggregation off the coast of Whyalla. Picture: Scott Portelli

Whyalla Dive Services owner Tony Bramley said the drop in numbers must prompt the reinstatement of a ban on fishing for cuttlefish in the northern Spencer Gulf.

The temporary ban, brought in to address the low population numbers in 2013, was removed last year after numbers improved.

A protection area remains in False Bay, stopping fishing in the animals’ favoured wintertime aggregation area, along with a temporary ban on catching cuttlefish at nearby Point Lowly.

Mr Bramley said it was “not rocket science” that allowing fishing had contributed to the drop in cuttlefish.

But state government data shows commercial fishermen caught 1902kg of cuttlefish this year, or roughly 1900 animals, much less than the 23,010kg caught last year.

Giant Australian cuttlefish at Stony Point on the Eyre Peninsula. Picture: Carl Charter / SATC

SARDI aquatic sciences research director Mike Steer said his organisation was “absolutely gobsmacked” by the size of last year’s population – but he said this year’s much smaller count was not cause for alarm.

“If we compare this year to 2019, when we felt the populations were relatively healthy, it’s only been a 6 per cent reduction,” he said.

The cuttlefish’s short lifespan has been cited as a cause of the drop in population size, Dr Steer said, along with changes in water temperature, the number of local predators and food supply.

“There appears to be adequate protection for the spawning population because all of the spots that we know what these animals aggregate are already protected from fishing,” he said.

“As long as they’re laying their eggs in protection then it’s fine and what happens after they lay their eggs is they die … they literally die of exhaustion.”

Whyalla Council chief executive Justin Commons said it was “still encouraged” to see average numbers continue to climb from “extremely low figures” a decade ago.