Appendix 1Timeline of the Harmful Algal Bloom
Timeline of the 2025 South Australian Harmful Algal Bloom (HAB)
September – October 2024
1.1A marine heatwave affected the south coast of Australia from September 2024, which led to marine temperatures being on average 2.5 degrees higher than normal.
1.2As discussed in Chapter 3, a group of concerned academics wrote to the former federal Minister for the Environment and Water, the Hon Tanya Plibersek MP, in October 2024 following the detection of the marine heatwave to draw attention to the issue and request federal funding be allocated over the next decade to mitigate any of the effects of the marine heatwave. This group more recently wrote to the current Minister for the Environment and Water, Senator the Hon Murray Watt, to draw attention to the current HAB in South Australia (SA).
March 2025
1.3On 18 March 2025, the SA Environment Protection Authority (SA EPA) stated that it had received 'multiple reports that dead fish and seahorses could be found on shore' at Waitpinga and Parsons beaches, and that it was working with Department of Primary Industries and Regions South Australia (PIRSA) Fisheries and SA Health to take water samples.
1.4On 25 March 2025, the EPA confirmed that Karenia mikimotoi (K. mikimotoi) was the cause of the HAB on the Fleurieu Peninsula.
1.5The SA Government confirmed reports of illnesses from surfers and swimmers and the presence of foam and dead marine life on beaches from March 2025. Local visitors to a Waitpinga Beach on the Fleurieu Peninsula reported having sore eyes, a sore throat and coughing, in some cases without even entering the water.
1.6PIRSA and the South Australian Research and Development Institute (SARDI) began monitoring the HAB and providing regular updates to the public.
April 2025
1.7In early April 2025, the SA EPA reported that the SA Government met with 'relevant state and federal agencies and affected councils' to discuss the HAB, and noted at the time that the Fleurieu Peninsula, Yorke Peninsula and Kangaroo Island were affected.
May 2025
1.8In early May 2025, the SA EPA reported that the HAB 'continues to affect beaches on the Fleurieu Peninsula, and Kangaroo Island and is increasingly prevalent along the southern coast of the Yorke Peninsula'.
1.9It was reported that PIRSA had tested the waters at Oyster Bay in Stansbury and had detected brevetoxins. This result caused PIRSA to direct oyster harvesters in the area to temporarily stop the harvesting of their product pending further advice.
June 2025
1.10On 3 June 2025, the SA Government held the Harmful Algal Bloom Science Forum which 'brought together leading scientists from State and Federal government agencies, national research institutes and universities, and the private sector' to discuss the impacts of the current HAB and options for HAB control and monitoring. Experts from the Cawthron Institute, a New Zealand (NZ) independent science organisation, also presented on the NZ perspective of dealing with fish-killing HABs and the Karenia strain of algae.
1.11In early June 2025, the SA Department for Environment and Water (DEW) and PIRSA announced that water testing revealed the Karenia strain of algae was present in the Coorong North lagoon between Seven Mile Basin and Long Point, with experts believing the algae 'flowed through the Murray Mouth and into the lagoon’ during the 26 May 2025 storm and 27 May 2025 high tide.
July 2025
1.12In early July 2025, DEW reported that K. mikimotoi had been detected in the West Lakes and the Port River, and that the HAB was at that stage:
… also affecting the eastern and western coastlines of Spencer Gulf, Investigator Strait near North Cape on Kangaroo Island, Troubridge Point on Yorke Peninsula, the Coorong’s North Lagoon and along the coastline from Victor Harbor to Robe.
1.13DEW also noted that there had been 'multiple reports of fish deaths along the metropolitan coastline', including a dolphin carcass at Tennyson Beach and the carcass of a great white shark at Port Broughton, Yorke Peninsula, following a storm on 24 June. DEW said that ' while it is not uncommon for marine mammal carcasses to wash ashore after winter storms, both the dolphin and shark [were] being tested to determine if the algal bloom contributed to their deaths'.
1.14On 8 July 2025, the SA Government announced that fishing licensing fees would be waived for the June quarter, in recognition of the ongoing disruption to commercial fisheries and aquaculture operations.
1.15In mid-July 2025, underwater footage captured at the Zanoni shipwreck in the Upper Gulf St Vincent Marine Park 'show[ed] many of the sponges, cold water corals and other filter-feeding organisms [were] clearly impacted' by the HAB (see figure below).
Figure 1.1Underwater footage of the algal bloom in the Upper Gulf St Vincent Marine Park
Source: South Australian Department for Environment and Water, Fisheries vessel inspects harmful algal bloom, 22 July 2025 (accessed 19 August 2025).
Underwater footage captured by the patrol vessel Southern Ranger in the morning of 16 July 2025, at the Zanoni shipwreck in the Upper Gulf St Vincent Marine Park.
1.16On 17 July 2025, the SA Minister for Primary Industries and Regional Development, the Hon Clare Scriven MLC, wrote to the federal Minister for Agriculture, Fisheries and Forestry, the Hon Julie Collins MP, seeking changes to the eligibility criteria for the Commonwealth Government’s Farm Household Allowance program and Rural Investment Corporation low interest loans, to provide financial support for SA's wild catch fishers.
1.17On 21 July 2025, the federal Minister for the Environment and Water, Senator the Hon Murray Watt, travelled to SA to inspect the impacts of the HAB. The Commonwealth Government announced a $14 million investment to support the SA Government’s efforts to respond to the effects of the HAB on the environment, as well as providing assistance to affected communities and industries. SA Premier, the Hon Peter Malinauskas MP, welcomed the federal funding, however he reiterated calls for the HAB to be declared a national disaster.
1.18On 22 July 2025, the SA Government’s Emergency Management Committee of Cabinet agreed to a HAB support package, contributing $14 million to match the Commonwealth Government's contribution. The support package included the following key measures:
Science and research
Coastal Monitoring Network—expanded early detection and monitoring of HAB species through real time sensors (buoys), satellite imagery and oceanographic modelling, with rapid detection of HABs and early warning systems for industry. ($8.5m)
New national testing laboratory in SA for HAB and brevetoxin/biotoxin testing, to increase the speed at which samples can be analysed. ($2m)
Rapid assessment of fish stocks and fisheries to quantify impact, including modelling ecological impacts on near shore marine ecosystems and all sanctuary zones utilising remote underwater video surveys and dive surveys. ($3m)
Citizen science—rapid meta-analysis of citizen science records and documented ecological impacts to provide a baseline understanding from which to assess recovery.
Develop a dedicated harmful algal bloom response plan for future bloom events.
Communications
Harmful Algal Bloom Taskforce to meet every Thursday, with a media conference to follow to keep the public informed on latest developments.
Public forums for impacted coastal communities and a trusted single point of information and contact for timely, accurate, and clear communication to industry and the public including a single phone hotline, website, consistent physical signage and information.
Public information campaigns focused on rebuilding confidence and driving visitation to our coastal regions and marine based tourism businesses and promoting the seafood industry and benefits of recreational fishing. ($2m)
Community support and clean up
Community Fund to support activities and small projects in affected communities. ($3m)
Beach clean-up funding for local government to assist cleaning up dead fish and marine life. ($1m)
Industry support
$10,000 Small Business Support Grants for eligible small businesses.
Financial counselling, mental health support and workforce advice to assist affected small businesses to develop recovery and continuity plans, understand the short and long-term implications, and help manage financial and mental wellbeing.
1.19Also on 22 July 2025, DEW announced that the SA Government had established the Harmful Algal Bloom Reference Group, comprising 'representatives from Seafood Industry South Australia, RecFish SA, Conservation Council, Tourism Industry Council and First Nations groups'. The Reference Group would report to the Harmful Algal Bloom Taskforce, and:
Represent sectors to identify key issues for government to consider in managing and recovering from the algal bloom.
Identify opportunities to further engage with and provide more information to industry sectors, stakeholders and the community.
Provide ideas for government consideration to support an expanded scientific monitoring program.
1.20On 28 July 2025, the SA Government announced that in addition to the $10,000 Small Business Support Grants, grants of up to $100,000 would be available for significantly impacted fisheries and aquaculture businesses. This would include:
Immediate payment of $25,000 for fisheries or aquaculture licence holders forced to close by authorities for more than one month or a 50 per cent reduction in catch/harvest for a three-month period since April.
An additional payment of up to $75,000 where a 50 per cent reduction in turnover can also be demonstrated. Payments will be tiered based on turnover.
1.21The SA Government also announced the fishing licensing fees would be waived for the September quarter.
August 2025
1.22On 3 August 2025, the SA Government announced new measures to support fishing activity during the HAB and to support the recovery of fish stocks following the event. These measures included:
$300,000 to install a strategically placed recreational fishing reef in an impacted Gulf region to support the survival and reproduction of key recreational species and allow real-time monitoring for citizen scientists, schools, and researchers;
Boosting regional tourism by supporting RecFish SA to deliver a series of four fishing events and competitions in regional areas in conjunction with local tackle stores and businesses;
Providing RecFish SA a grant of $200,000 to further support more than a hundred community fishing clinics and programs across South Australia, fishing events and competitions, and engagement with recreational fishing clubs to boost participation
1.23Starting on 5 August 2025, and continuing throughout the month, the SA Government held a series of community forums across a range of regional and metropolitan locations, to 'provide updates on the response and recovery efforts, including the latest science, public health advice, and support measures for affected communities and industries'. The forums enabled communities to ask questions and:
… hear directly from Premier Peter Malinauskas, Deputy Premier Susan Close and other ministers, as well as scientific and public health experts including Chief Public Health Officer Professor Nicola Spurrier and [SARDI's] Professor Mike Steer…
1.24On 12 August 2025, federal Environment Minister, Senator the Hon Murray Watt, met with marine scientists 'to explain the government's funding package and plans for further ocean protection'. On the request of the marine scientists, Minister Watt subsequently wrote to the Chair of the Threatened Species Scientific Committee to 'urgently consider' whether any local SA flora and fauna species should be added to the 2025 Priority Assessment List due to the HAB.
1.25The Environment Minister also wrote to the Threatened Species Scientific Committee (TSSC) on 12 August to highlight the algal bloom impacting the coast, and its link to the mass mortality of marine species. The Minister requested that the TSSC ‘consider as a matter of urgency any species and ecological communities that should be assessed as a priority for possible inclusion on the national threatened species list’. Department of Climate Change, Energy, the Environment and Water (DCCEEW) officials met with the TSSC Chair on 13 August 2025 to initiate this process, and again on 22 August 2025. The TSSC met to discuss this issue on 28 August 2025, and were set to discuss this again between 1–4 September 2025.
1.26On 13 August 2025, Minister Watt visited Adelaide to 'meet with impacted businesses, industry and the community', and joined SA Ministers, the Hon Susan Close MP and the Hon Clare Scriven MLC, to undertake offshore water sampling with PIRSA. It was announced that SA's water testing regime for the HAB had been 'significantly expanded to 76 sites as part of the $28 million support package', including 'the addition of 18 new regional testing sites', and that the use of drones for water sampling at remote locations was to be trialled in the coming weeks.
1.27On 19 August 2025, the SA Government announced changes to the grant criteria for business support grants, to expand eligibility. The application closing date for the grants was also extended from 12 September 2025 to 30 November 2025.
1.28On 20 August 2025, Prime Minister, the Hon Anthony Albanese MP, visited Adelaide and Kangaroo Island, and announced $6.25 million of federal funding:
$4 million of direct funding to local government for grants to assist local communities;
$2.25 million in targeted scientific research support; and
$2 million to enhance the monitoring and data collection of marine heatwaves through the CSIRO's water quality system, AquaWatch.
1.29In addition, the Prime Minister mentioned that the Commonwealth would contribute $250,000 for algal bloom related research informed by the South Australian Algal Bloom Science Panel through the National Environmental Science Programme.
1.30The Prime Minister also announced that a new stream of Regional Investment Corporation funding would be established to provide long-term support certain aquaculture sectors to deal with significant ecological events such as HABs.
1.31In a joint media release between the Prime Minister and Premier Malinauskas, it was announced that as part of the $28 million support package, the company Agilex Biolabs has been engaged to develop methods to test for brevetoxins in Australia. Currently, any testing undertaken by SASQAP includes having to send samples to New Zealand for analysis, which can delay results by up to a week.
1.32In a joint media release from Minister Watt, Premier Malinauskas, and Deputy Premier Susan Close MP on 28 August 2025, it was announced that a trial of ‘air bubble curtain’ technology would be installed on the Cuttlefish Coast in the Upper Spencer Gulf to attempt to protect cuttlefish eggs and hatchlings. The technology works by creating an underwater barrier that can disrupt the movement of the HAB, preventing it from passing through this barrier. This prevention method is new to SA and can only be used to prevent the HAB from spreading to the area and cannot be used in areas where the HAB is already present.
September 2025
1.33In early September 2025, the SA Government’s Algal Bloom Coordination Unit accelerated beach clean up patrols drawing on staff from Disaster Relief Australia, IPA Rangers from the Point Pearce Aboriginal Corporation, and the Goolwa Pipi Company. Access to facilities was provided by Surf Life Saving South Australia.
1.34Campaigns to encourage public support for the South Australian seafood industry and coastal locations were launched in September, including the ‘Buy SA Seafood’ campaign and ‘Coast is Calling’ voucher program.
1.35Community forums continued to be held by the SA Government in a variety of locations across the South Australian coast.
1.36Health advice was updated in September 2025, and people with asthma were advised to carry reliever medication with them while on beaches, take preventive medication as prescribed, and update asthma management plans.
October 2025
1.37On 2 October 2025, it was announced that there would be a phone hotline established to provide up to date information to the public as well as having options for reporting fish kills or other marine mortalities. The hotline went into operation on 3 October 2025.
1.38On 14 October 2025, the SA Government released the Algal Bloom Summer Plan, which set out funding from the Commonwealth and State governments to address the effects of the algal bloom, and funding for research and marine restoration. The Summer Plan also provides for the expansion of both the Buy SA Seafood and Coast is Calling campaigns. The Algal Bloom Summer Plan is discussed in further detail in Chapter 3 of the report.