Whyalla wipeout fears: cuttlefish usually gather in their thousands, but few have appeared since a massive algal bloom

Normally by this point in the season, with water temperatures below 17C, there should be thousands of giant cuttlefish turning up, according to Manny Katz of the Whyalla Dive Shop. Photograph: Stefan Andrews

Mid-June is usually the peak time for giant Australian cuttlefish to gather near Whyalla, in South Australia’s Spencer Gulf.

Nearly every year, they come in their thousands – and sometimes hundreds of thousands – to assemble in the shallows to breed. It’s a globally unique natural phenomenon, celebrated locally as “Cuttlefest”.