Marine scientists warn Australia at risk from future harmful algal blooms

A nightmare algal bloom of the kind that has killed thousands of marine wildlife and decimated coastal towns across South Australia could one day hit other parts of Australia, a marine expert has warned. Marine biologist Shauna Murray, speaking with NewsWire this week, said it was only “luck” that had so far shielded NSW, Victoria, Tasmania and Queensland from suffering the devastating social, economic and environmental impacts that are sweeping through South Australia. “We’ve just been lucky enough the blooms of karenia (a harmful algae species) in NSW were not of this scale,” she said. “But there is no real reason we couldn’t have one of this scale. It happens. “We absolutely need to get our ducks in a row and understand what we are dealing with.” The current bloom, first detected in March, has now hit some 30 per cent of South Australia’s coastline, throwing the state’s lucrative fisheries and coastal tourism industries into disarray. A senate inquiry into the event held public hearings across Adelaide, Port Lincoln, Ardrossan and Victor Harbour this week, revealing the crushing human impact from the complex scientific phenomenon. Button Fisheries owner Bart Butson, speaking in Ardrossan on Thursday, said he hadn’t seen any calamari or squid in the St Vincent Gulf for the past 2½ months. “That is just incredible for us. It shouldn’t happen,” he said. Port Lincoln Mayor Diana Mislov, appearing on Wednesday, said fishermen in the iconic “seafood capital of Australia” were struggling to catch fish in the Spencer Gulf. “We’re feeling it on our bays – the fish just aren’t biting, they are not there,” she said. “I’ve had stories – a fisherman fishes for squid, he hasn’t seen squid since April in our bays. “So those fishermen are having to drive to the west coast, take their boats over there – 600km away – and go fishing from those locations.” Ian Mitchell, the manager of Safcol’s Adelaide Fish Market, said the next 12-24 months could deliver dramatic lay-offs across the embattled industry. “The next 12-24 is the most important because if we keep going on a downward trend, then my staff will probably leave because I won’t be able to give them the hours and to find staff in this industry is a hard thing to do,” he said. There are some 50,000 species of algae, and only about 200 of those are considered harmful. Harmful algae produce toxins that can kill and contaminate marine life. Species of karenia are causing the current bloom event. Other states have already suffered blooms. In December 1989 and May 2003, a karenia bloom hit salmon farms in Tasmania, wiping out $4m in value. In 2010, a pseudo-nitzschia cuspidata bloom in Wagonga, NSW shut down shellfish harvesting for four months for a $1m loss. University of South Australia Associate Professor Craig Styan said South Australia’s 2025 bloom was unlikely to migrate into Victoria or other states. “There are two ways it could spread to other states,” he told NewsWire. “First, via currents moving east along the coast into Victoria, and possibly the west coast of Tasmania, which seems unlikely, and it would probably take a long time given the large distances involved. “Very broadly, the near shore currents in South Australia move from west to east, but once you get close to the coast, the oceanography does becomes trickier and very dependent on environmental conditions, coastal topography and needs expertise to model. “The second way, theoretically, is via ballast water in ships moving from one port to another. For example, if ballast water was taken on in one area to stabilise an empty ship and then released in another when they load. “However, the potential transport of harmful algal bloom in ballast water has been recognised as a potential risk for a long time and so explicit efforts to minimise this have been included in Australia’s ballast water management plan.” But the hearings have revealed that scientists and government officials are still largely in the dark about the root causes of the bloom and how it might develop and alter the environment. “We lack the necessary baseline data and consistent monitoring programs,” Dr Charlie Huveneers from Flinders University told the inquiry on Tuesday. “How can we tell you what has changed if we don’t even know what was there to begin with?” Professor Murray compared the situation to the early days of Covid. “We are dealing with something that is just really hard,” she told NewsWire. “If you imagine when Covid first started and there was a massive amount of science needed just to work out what was going on. We’re in a similar situation with this bloom. “It’s not that it is something is really known in other places and we just don’t know it. It’s new.” The environmental catastrophe was likely caused by three interconnected factors, the South Australian Department for Environment and Water said. First, a marine heatwave, starting in September 2024, warmed sea temperatures about 2.5C more than normal. Second, the 2022-23 River Murray floods washed extra nutrients into the sea, and third, a cold water upwelling in the summer of 2023-24 pulled nutrient-rich water to the surface. The bloom could last for months, the department warned, and local mayors, fishermen and tourism operators are bracing for a hard summer. “Do we get another dose of algal bloom building up on top of this one, and stretches on, and builds and builds and builds until it is out of control and becomes a national disaster,” Tumby Bay Mayor Geoff Churchett told the senators on Wednesday. Professor Murray said the scientific community’s knowledge gap was the result of decades of underfunding and government disinterest in constructing a clear picture of Australia’s marine landscape. “In Australia, we basically don’t fund that sort of basic taxonomy and marine biodiversity type work,” she said. “In good times, someone just goes out there and looks at the microbial community and establishes what micro algal species that we have in Australia. “We really have no real funding sources for basic taxonomy that is not directed towards an urgent problem, and because of that, we don’t really have any specialist who are able to do this work.” In its submission to the inquiry, the Australian and New Zealand Marine Harmful Algal Bloom Network calls for urgent funding to establish a nationally co-ordinated monitoring and research program. To date, the South Australian and federal governments have announced a joint $28m support package, with some of the money allocated to research. “We haven’t really valued marine biodiversity to the extent we should have and now we are seeing to our detriment that when we needed the knowledge and the expertise, it’s sort of thin on the ground,” Professor Murray said. The inquiry will hold a final hearing in Canberra on September 24.