Record low cuttlefish numbers at Point Lowly spark scientific investigation

Each winter, Point Lowly hosts the world’s only giant Australian cuttlefish breeding aggregation, typically drawing over 100,000 individuals along an eight-kilometre reef. In 2026, divers counted fewer than ten cuttlefish, a decline described as unprecedented by officials. The South Australian government’s surveys in July confirmed the collapse, which follows a severe algal bloom dominated by Karenia cristata that may have harmed the cephalopods directly or reduced their prey.

Warm winter water temperatures have been noted, though they have not previously triggered such a crash. Authorities responded with a 90-day ban on tourism to protect the remaining population, and Invertebrates Australia is convening a panel of experts and operators to compile evidence for an IUCN Red List assessment. While the bubble curtain installed to shield eggs proved unnecessary, the event highlights the fragility of this heritage-listed marine phenomenon.