Whyalla Cuttlefish: On the West Coast in the Eyre Peninsula region of South Australia

Walk along any South Australian beach during winter and you'll find reminders of a marine creature that continues to fascinate biologists like Dr Tony Fowler from the SA Research and Development Institute.

“These are internal skeletons from the cuttlefish,” Tony said as he picked up a chalky white object from the beach. “You see plenty of them scattered along the coastline. The cuttlefish is found broadly through the inshore coastal waters of South Australia.”

But if you want to see where the Australian Giant Cuttlefish gathers in staggering numbers each year - travel to waters just north of Whyalla. Looking out from the top of the Black Point Boardwalk the shimmering waters of Spencer Gulf hide a winter phenomenon - as thousands of Cuttlefish seek out a rock ledge or crevice in which to spawn.

The migration of Australian Giant Cuttlefish to the top of Spencer Gulf remains one of the great underwater experiences for divers from around the world. It occurs in very shallow water at a particular point in the Gulf as Tony explained.

“There's an unusual reef structure between Black Point and Point Lowly in Northern Spencer Gulf. And that reef structure consists of large plate like rocks of quartzite bedrock.

“And there are numerous cavities underneath those rocks which the cuttlefish use for the deposition of their eggs. So the females get in under the rocks and they stick the eggs to the underside of those rocks.”

The Australian Giant Cuttlefish can change colour to avoid detection. But that wouldn’t stop you spotting them during May to August when thousands of the alien like creatures invade the gulf.

“The numbers get up to a hundred and seventy thousand on an eight kilometres stretch of reef. But that stretch of reef is eight kilometres long but it may only be up to a hundred metres wide.

“It is amazing actually. It's unique for cuttlefish around the world to have a spawning aggregation of that density in one place. It is unique.

“They are quite a peculiar animal in that they can change colour according to their environment. They have a very sophisticated system of chromatophores and they can change colour and they use those changing colours to signal to each other. So they actually communicate to each other.”

They also put on an amazing courtship display - regardless of who’s watching.

“The animals are almost oblivious to divers. They just participate in their normal behavioral activities despite the fact that there might be numerous divers in the vicinity. So the divers are treated to this feast of interactive animals in their natural environment.”

The Australian Giant Cuttlefish remain in numbers at the top of the gulf until the end of August. (approx.) For more information and dive gear contact Whyalla Diving Services on (08) 8645 8050. If you have any further questions please email info@postcards-sa.com.au

Australian Giant Cuttlefish Migration
Top of Spencer Gulf
May to August

Whyalla Diving Services
(08) 8645 8050