How Hard is the Algal Bloom Hitting South Australia? Impacts on Marine Life & Humans

Dead sea creatures washed onto the beach by a toxic agal bloom. Image: Stefan Andrews/Great Southern Reef Foundation

Recently our Environment Institute members have been very active in the Harmful Algal Bloom (HAB) space. We’ve pulled together their key media contributions, covering which marine life are safe or at risk, the role of climate change in driving these events, and the long-term solutions scientists are exploring to better protect our oceans in the future.

Not all species are equal

Karenia mikimotoi has disrupted life in waters for those above and below the sea. However, in recent news, it is reported that Southern Right Whales are safe from the Harmful Algal Bloom (HAB) affecting South Australia.

Environment Institute member, Professor Ivan Nagelkerken, spoke to The Advertiser and Channel 7 News providing reassurance that these whales that grace our waters are safe from the HAB, as there is no direct evidence that the bloom impacts them. Marine life like seals and dolphins remain at risk as their direct food sources are impacted by the HAB. 

“Southern Right Whales feed on krill in deeper waters, not in South Australian Gulfs, so their food supply remained unaffected by the bloom,” shares Professor Nagelkerken.

“I’m much more worried about the collapse of the food web, leading to loss of food opportunities for bigger fish and sharks and sea lions and so on,” he said.

Professor Nagelkerken explains that the Karenia mikimotoi HAB is a type of bloom that doesn’t produce toxins, so seafood is still safe to consume, however it can cause discomfort.

“It is an irritant, so you can either inhale particles through the air, or it can irritate skin,” Professor Nagelkerken said.

“Whales are just like humans, so that’s very possible, but that would not be something that you would expect to cause mortality.”

Human health impacts

Professor Phillip Weinstien spoke with ABC Online and ABC TV News, sharing how the HAB continues to affect humans and why.

He described how as a reactive oxygen species, like hydrogen peroxide, when used too much it becomes an irritant as it contains low levels of concentration.

The respiratory symptoms of the bloom are compared to experiencing asthma, he says. "If you're an asthmatic, symptoms can last a little bit longer if you're precipitating an asthma attack," he said.
"Generally, if you're more than 300 metres away from the ocean, you're pretty safe. If you've got sea frontage and a good wind, you can get symptoms."

This is a different story for marine life, Weinstein shares: "If you're a fish swimming in it and filtering it through your gills you've got a pretty intense exposure."

Scale of the devastation

Future Making Fellow Dr Dom McAfee recently featured on BTN, sharing that at least 470 different species have been killed in relation to the algal bloom – suggesting this number could be much larger.

“The dead marine life we see is typically washed up on the shoreline, but there's a whole range of organisms stuck to the sea floor that aren't going to wash ashore. What we're seeing on the beach is sadly the tip of the iceberg,” says Dr McAfee.

As we know about 30% of the coastline has been affected by the Karenia mikimotoi. Dr McAfee shared how the marine life that has washed onto the shore, their deaths are an indirect cause of the bloom.

“There was a dolphin that washed up not that long ago. It was determined that it had died of starvation, so the loss of its food source, which was probably impacted by the bloom, is now cascading down and flowing to higher trophic levels like dolphins,” he shared.

Currently, scientists have identified at least twelve other species of bloom, making it crucial to understand the impact of them all.

Moving towards protection and recovery

The inquiry is underway into the Algal Bloom and the findings of it should be released in October. We were fortunate enough to be invited and submit an inquiry which can be found here.

Dr McAfee says there isn’t a lot that can be done right now to dissipate the bloom on a larger scale, however there needs to be longer term solutions in place.

As climate change continues, the bloom is something that is set to become more common due to heatwaves and other weather conditions that enable them to flourish, explains Dr McAfee.

“We need to think proactively about what we are going to do about that. Obviously, tackling climate change is vital, but it's a long global battle.”

Dr Nina Wootton, featured on ABC Online, commented on the big challenge we face with the HAB as it forces researchers into a unique situation, also agreeing that with climate change this is much more likely to occur again in future.

“If we can use this bloom to actually learn some things … we're hopefully in a better position to deal with it the next time." She says.

Dr Wootton adds that researchers are looking at other forms of ecological interventions such as seagrasses or reef species that filter algae from water, like oysters. However, this work won’t be a fast turnaround, stressing the importance of being careful of what we’re putting into the marine environment.

"If it's not already there, obviously you don't want to put it in and have a cane toad situation."

Unfortunately, no one is sure as to when the bloom will end and it’s difficult to observe what solution may be the most useful.

Speaking to ABC Radio Drive, Dr McAfee commented on the recent bubble curtain project, an effort aimed at protecting the eggs of giant Australian Cuttlefish and has been allocated $700,000 of funding by the State Government, Premier Peter Malinauskas.

Dr McAfee believes “this is a very positive step” and “it’s a great idea” to protect the South Australian Marine environment.

“While the bloom is still here, I think it's worth trialing these technologies. They can't be used, as the Premier said, to disperse the algae at large scales, but they can be used to protect really important, vulnerable sites, and that's exactly what this site is,” says Dr McAfee.

The cuttlefish are “voracious feeders”, with no certainty of them having a life in a lab as there isn’t certainty of them surviving being released again.

“The bubble curtain technology is something that can be installed to protect them in situ and just to improve their chances of survival persisting through the next few months.”

“The beauty of the bubble curtain is that you can tightly control its use, so it can be turned off. They'll be detecting, looking for Karenia and looking for the moving bloom.”

Dr McAfee acknowledges that in other locations cephalopods, cuttlefish, and octopus have been very susceptible to this bloom.

“We can see that by noticing them washing up on the shore. It's important to recognise that not everything that washes up on the shore is directly related to the death of the bloom, and a lot of these cuttlefish now that they've finished their breeding season, will die and actually wash ashore.”

He does say that in the affected areas the cuttlefish are heavily impacted, and we only see the ones that wash ashore.

“When I've been diving, you know, you do see rotting carcasses of cuttlefish here, there, and it's quite a common sight.”

As HAB continues to evolve, the full impact is being discovered along the way. One thing is for certain, and that is climate change will make these events more frequent and severe. Our members are working to not only understand the consequences, but to develop proactive responses to better safeguard coastal communities and marine life.

Environment Institute HAB Capability Statement

We produced and published the Environment Institute Harmful Algal Bloom (HAB) Capability statement, in which key research priorities have been identified. This Statement lists our leading researchers, their expertise, partnerships and their key publications, outputs and contributions.

By creating this statement, we’re able to clearly communicate how we can contribute, and are contributing, to actionable impact related to the HAB. You can download and read the HAB capability statement. You can also support the Environment Institute’s research into the HAB.

You can download and read the Environment Institute’s full submission (number 40 of 44) here

Read our other blogs on HAB

• An 'Underwater Bushfire' Sparks Urgent Calls Urgent Calls for Action in South Australia
• How South Australia's Algal Bloom Is Threatening Marine Life and Public Health
• Harmful Algal Bloom and Human Wellbeing Impact

Media Features: 

• Professor Ivan Nagelkerken (The Advertiser print + online, Gold Coast Bulletin, The Courier Mail, Herald Sun, Channel 7 News)
• Professor Philip Weinstein (ABC Online, ABC TV, MSN)
• FMF Dr Dom McAfee (ABC Radio Drive and BTN)
• Dr Nina Wootton (ABC News Online)