3 days ago
Tragic beach discovery sparks fresh alarm over ‘horror' issue in Australia: ‘Devastating'
One of the country's leading marine biologists is warning there may be long-term ecological consequences in the wake of the toxic algae bloom currently killing thousands of animals in waters of the South Australian coast.
Professor Shauna Murray, from the UTS School of Life Sciences, said she doesn't believe the crisis has been managed poorly, in response to some commentary earlier this week insisting the event would have received much more attention and swifter action if it had impacted eastern states like New South Wales or Queensland.
But, Murray said, there is an opportunity for Australia to take global leadership when it comes to marine ecosystem threats. For months now, many thousands of marine animals, spanning over 390 species, have been washing ashore dead along beaches in the south, with the toxic algae Karenia mikimotoi to blame.
Some believe that figure is modest, with not all deaths being witnessed, and incidents being heavily reliant on reporting. In an interview with Yahoo News Australia, Murray said she believes "it's too early to say exactly what factors" are driving this particular harmful algal bloom (HAB) of Karenia mikimotoi, though in general, climate change is "certainly having long-term impacts on HABS".
"Every species of harmful algae has highly individual conditions that it grows under, and these vary. Karenia mikimotoi is normally a temperate species, which blooms in the north of China, the north Atlantic, and other countries," she explained.
"However, having said that, it could be that a one-degree increase in water temperatures over an extended time frame could be contributing to the growth of the species. Other conditions, such as currents, water nutrients, and other factors, are also contributing. HABs are almost always due to a specific combination of factors unique to the algal species."
Murray believes there could be long-term ecological consequences, given that after a Karenia species bloom in Wellington Harbour in New Zealand in the 1990s, it took about three to five years for the ecosystem to recover.
Though the current bloom involves similar Karenia species and brevetoxins, it is impacting a much larger area. "Hence, while I think habitat collapse is unlikely, I do think that we will need to closely monitor fish and invertebrate species abundances to understand impacts," Murray said.
On social media, dozens of individual examples continue to emerge from beaches around the state that have been inundated with carcasses, attracting tens of thousands of responses from upset Australians, questioning if more could have been done. "This is literal horror," one person said.
"We should all be losing it at this. This is devastating," another said, with each comment attracting hundreds of likes.
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But according to Murray, the response was as appropriate as it could have been. "I think the event has been handled as well as it could be, given that there are very few (literally about five to 10) marine HAB experts in Australia, including myself," she said.
Murray said Australia has an opportunity to develop a strong response to harmful algal blooms in future, which could serve as a model for other countries. She noted that threats to marine environments like coral bleaching and kelp forest dieback are well known, and the increasing incidence of harmful algal blooms is one of the more manageable challenges.
"This is not a failing. HABs are very well managed in Australian waters relative to the marine aquaculture industry, as they are regulated, monitored and managed, and have been for many years," she said.
"This particular SA situation is quite unusual in the length of time the HAB has persisted and the area over which it has extended, as well as the fish killing mechanisms and hence the wider impacts. I think we need to learn from this and build more expertise in the field, so that more people have the relevant knowledge and skills for when situations like this arise next time."
While federal governments typically don't get involved in matters concerning state waters, Murray said it may now have a role to play given the scale of the outbreak, particularly in funding research and future monitoring systems.
"I believe the best role would be for them to fund research and set up systems for future monitoring, so that if something like this were to happen again, we would be prepared," she said.
"So far, we have learnt that the main microalgal species is Karenia mikimotoi. But it's not the only species of Karenia present, and it makes up around 50 per cent or more of the microalgae in the water in some regions, with the rest being a mixed standard marine microalgal community.
"We still need to understand the identities of the other HAB species, their abundance and distribution, the microalgal producers of brevetoxins, and the toxic mechanisms of other Karenia species present.
"We also need to fully investigate oceanographic conditions before, during and hopefully following the HAB to develop models to understand the drivers of this one."
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