Massive, Persistent Toxic Algae Outbreak in Australia Claims Lives of Over 14,000 Animals
Toxic Algal Bloom Off South Australia's Fleurieu Peninsula Continues for Five Months
A toxic algal bloom off South Australia's Fleurieu Peninsula has been ongoing for five months, affecting over 4,500 square kilometres of coastal waters and causing the death of thousands of marine animals.
The bloom, caused by an excess of Karenia mikimotoi, a type of plankton native to the area, has expanded to include the Gulf of St Vincent, where Adelaide is located. According to Dr Zoe Doubleday of the University of South Australia, the current algal bloom is an ecological disaster of national significance.
Dr Faith Coleman of Federation University Australia suggests that last summer's extreme marine heatwave was the dominant factor in the bloom's occurrence. Rising global temperatures could make such heatwaves more frequent and intense, according to Dr Coleman.
The bloom has affected a hundred kilometers of coastline and has been larger and more broad-ranging than any other harmful algal bloom (HAB) event in Australia's history, according to Professor Shauna Murray.
Government funding and response have been crucial in addressing this crisis. The South Australian government allocated AU$28 million to support research, monitoring, and community assistance programs.
Agencies and universities are closely monitoring the bloom's spread and impact using water sampling, acoustic receivers, and tagging of marine species. Researchers use data models to predict bloom development, considering factors such as seasonal nutrient upwelling and ocean temperature changes to anticipate and prepare for bloom movements.
Authorities have installed signage advising the public to avoid contact with discoloured or foamy water and monitor health risks. Beaches remain open but users are warned to heed safety instructions.
Emerging research is looking into cultivating seaweed and other bioremediation techniques, inspired by First Nations knowledge systems, to potentially improve coastal water quality and reduce conditions favoring harmful blooms.
The bloom is linked to warmer-than-normal sea temperatures, calm water conditions, and elevated nutrient levels from extreme weather events. Mitigation efforts must consider climate-related factors such as marine heatwaves and nutrient runoff management over the long term.
Currently, no practical method exists to directly dilute or dissipate the bloom; its duration depends largely on natural weather and ocean fluctuations. Consequently, ongoing investment in monitoring, public communication, ecological research, and long-term coastal management are central to mitigating impacts and reducing future bloom risks.
Dr Nina Wootton of the University of Adelaide suggests solutions to the bloom include reducing nutrient runoff, better coastal monitoring, acting on climate change, and restoring seagrasses and kelp forests. Restoration of seagrasses and kelp forests could provide global benefits through carbon storage, but is difficult to achieve while the bloom is underway.
Dr Doubleday also mentions that there is no quick fix for the bloom. Incoming storm activity is hoped to end the bloom, at least for this year, by dispersing the algae and affecting its growth.
Despite the ongoing crisis, citizen scientists have recorded 458 species in an iNaturalist folder. Dr. Ian Wright of Western Sydney University suggests the bloom could meet the definition of a national disaster and qualify as a 'Matter of National Environmental Significance' under Commonwealth Environmental legislation.
Conspiracy theories regarding the cause of the bloom, such as Chinese warships, have been debunked by Dr Coleman. Expectations that a major storm event in May would end the bloom were not met. Dr Wootton also mentions that there is no quick fix for the bloom.
- Climate change, influenced by rising global temperatures, could make marine heatwaves more frequent and intense, leading to longer-lasting harmful algal blooms like the one off South Australia's Fleurieu Peninsula.
- In the effort to combat the ongoing algal bloom, scientists are looking into innovative solutions such as cultivating seaweed and other bioremediation techniques, inspired by First Nations knowledge systems, to improve coastal water quality.
- The academic community is actively involved in monitoring and researching the impact of these harmful algal blooms on marine life and the environment, employing technology like water sampling, acoustic receivers, and tagging of marine species.
- To address the current crisis and minimize the risks of future blooms, it's important to focus on long-term strategies that consider climate-related factors like marine heatwaves and nutrient runoff management, as well as restoration of seagrasses and kelp forests, which offer benefits such as carbon storage.
