Full Breakdown
Record Low Turnout of Giant Cuttlefish on South Australia’s “Cuttlefish Coast”
8/30/2026, 2:23:58 AM
Core Event
Official estimates released this month put the number of giant Australian cuttlefish (Sepia apama) observed this winter at 1,811, a 97 % drop from the 63,000 counted the previous year. The same surveys recorded only about 440 eggs along the eight-kilometre stretch of coastline, far fewer than the millions normally laid. Divers from the Department of Environment and Water (DEW) conducted eight one-hour dives over two days in July, inspecting the undersides of rocky reefs to tally the eggs.
Environmental Context
State officials attribute the sharp decline to a toxic algal bloom that has affected the coast for more than 18 months. The bloom, first detected in March of the previous year, is linked to ocean warming, marine heatwaves and nutrient pollution—factors amplified by climate change. Researchers note that cuttlefish, along with other cephalopods, are especially vulnerable to such toxins.
Official Statements & Responses
- A spokesperson for South Australia’s Department of Primary Industries and Regions said cuttlefish numbers “naturally fluctuate” with environmental conditions.
- Prof Mike Steer, executive director of the South Australian Research and Development Institute, called the current estimate “disheartening” but emphasized that the population has previously rebounded when conditions improve.
- DEW tasked divers like Manny Katz to assess egg numbers to gauge the likely size of next year’s cohort.
Criticism & Opposition
Stefan Andrews, co-founder of the Great Southern Reef Foundation, is urging that the giant cuttlefish be listed as a threatened species. He described the decline as “catastrophic” and said the algal bloom is a “leading plausible explanation,” though he acknowledged that definitive proof of causation is still lacking. Andrews warned that the low adult and egg counts could make the next breeding season especially challenging.
Data & Statistics
- Historical surveys show a low of 13,500 in 2013 and a high of 247,000 in 2020.
- After the 2013 low, the population rebounded to over 100,000 within two years.
- This year’s count of 1,811 adults and 440 eggs represents the lowest recorded observation for the event.
The combination of unprecedented low adult numbers, minimal egg deposition, and an ongoing algal bloom has sparked urgent calls for conservation action while scientists continue to monitor whether the population can recover under improving environmental conditions.