By Belinda Willis
Giant Australian Cuttlefish have returned to their South Australian breeding ground in higher numbers this winter than have been seen in decades.
Early estimates are hovering higher than 200,000, numbers not seen since the population of the world’s largest cuttlefish species began to decline in the 1990s.
South Australian tourist numbers are rising along with the cuttlefish as locals flock to see the bizarre cephalopods perform their unique mating pattern.
The Giant Australian Cuttlefish (Sepia apama) gather along an 8km stretch of rocky reef at Point Lowly in the Spencer Gulf, about 20km east of Whyalla and almost 400km northwest of the South Australian capital Adelaide.
Nicknamed the “rock stars of the ocean” because they live fast and die young, the cuttlefish have a life span of just 12-18 months.
This makes each May to August breeding season critical because the number of surviving eggs one year directly impacts the number of adult cuttlefish that return the next year to breed.
The unique congregation is linked to the cuttlefish being drawn to dark rocks and crevices at Point Lowly that help protect their eggs from light.
Males, which can reach 50cm long and weigh 10kg, employ a fascinating mix of camouflage to match rocks or seaweed, sparring and changing colour to win female attention in a colourful dance.
The females lay between 100 and 300 eggs that hatch babies the size of a thumbnail, and then these baby cuttlefish move along the sea bottom and into the Upper Spencer Gulf.
Whyalla dive and snorkelling tour leader Tony Bramley said his snorkelling tours and scuba diving trips have been booked out over the past weeks because of the increased numbers.
“Compared to even the last two seasons that have been very good, this has been exceptional,” Bramley said.
Scientists are still crunching this year’s numbers but Bramley estimates some 250,000 of the largest cuttlefish sub species in the world have arrived in their Point Lowly winter breeding ground.
“There’s absolutely nothing like it in the world, it’s so reliable to see the cuttlefish, it’s safe, accessible, South Australians are so lucky to have one of the most precious marine attractions on their doorstep,” Bramley said.
Some controversy is surrounding this year’s breeding season after the South Australian government allowed fishing of the cuttlefish outside the restriction zone around Port Lowly for the first time since the grounds were protected in 2013.
Bramley said numbers had dropped to devastating levels after fishing targeted the species but in the past few years as numbers again flourished the cuttlefish had been attracting attention from all over the world.
Carl Charter is a co-founder of the not-for-profit Experiencing Marine Sanctuaries group that hosts talks and visits to the Giant Australian Cuttlefish breeding grounds.
He too thinks there could be double the numbers visiting this year compared to last year.
“It’s great news, I was up there myself a couple of weeks ago and there was probably double the numbers it was last year, you could walk directly into the water and see the cuttlefish in the shallows,” Charter said.
The group is currently organising a live streaming session on the state’s great southern reef for National Science Week including one event featuring leading cuttlefish researcher Professor Bronwyn Gillanders.
Professor Gillanders from the University of Adelaide said that the breeding season was attracting more interest and researchers each year.
“It really is quite spectacular,” she said.
“Film crews come from around the world to film that aggregation and researchers are also coming from around the world to study things like camouflage, you get a large sample size.
“I think the public is becoming more aware of the phenomenon.”
This piece was prepared online by Panuruji Kenta, Publisher, SEVENSEAS Media