South Australia's algal bloom is threatening one of the world's marine wonders, as it spreads north towards the Spencer Gulf. The bloom, caused by multiple species of the tiny dinoflagellate Karenia, has already turned the waters a sickly brownish-green color and suffocated marine life such as sand octopus, rays, and other creatures. The annual aggregation of giant cuttlefish, a spectacular natural event, is at risk of being affected by the bloom. The Great Southern Reef Foundation co-founder, Stefan Andrews, has recorded water visibility of less than one meter in parts of the region and observed multiple marine species dead or dying. The state government has established additional water testing sites to monitor the situation, but the bloom remains unpredictable. The giant cuttlefish, which can weigh up to 10 kilograms, are highly dependent on the previous generation for their survival. A trial 'bubble curtain' has been deployed to protect the cuttlefish and their eggs, but its effectiveness is uncertain. The situation is a grim reminder of the impact of climate change on marine life, and scientists are working to understand the causes and effects of the algal bloom.
