Hopes ‘monster swell’ coming to Australia’s southern coast may clear toxic algal bloom devastating marine life
Powerful waves could ‘eat away at the coastline’, forecasters say, but experts are crossing fingers for a silver lining
The Bureau of Meteorology (BoM) is forecasting a large ocean swell for the southern Australian coast, with hopes the conditions could help “flush out” the toxic algal bloom that has devastated marine life in South Australia.
A senior BoM meteorologist Angus Hines said the southern coast would experience sizeable waves, which midweek began in Western Australia before spreading across to the SA coast and would reach into parts of Victoria and Tasmania by Saturday.
Hines said coastal erosion was likely, warning fishers and boaters about hazardous conditions, including powerful waves that could “eat away at the coastline”.
A second burst of larger waves, reaching WA’s south-west coast on Monday, could result in “waves of maybe between 6 and 8 metres in height”, Hines said, noting that the southern coastline of Australia was “no stranger to getting big waves”.
He said that these powerful waves would then move to parts of the southern SA coast next Tuesday.
There are hopes the ocean swell may help to clear the deadly bloom of Karenia mikimotoi algae, which has been devastating SA marine life since March. To date, the algal bloom has affected more than 430 different species, with about 13,000 dead marine animals recorded as part of the SA Marine Mortalities project.
Dr Zoe Doubleday, a marine ecologist at the University of South Australian, said that winter storms to date had not cleared out the algal bloom.
“This big monster swell coming through could be the thing we need even though it might cause damage in other areas, but we are really treading in unknown territory here,” she said. “It could be the thing we need to mix things up and flush out the system particularly around the coastal waters.”
A big storm might help flush out the bloom from gulf waters, Doubleday said, “particularly now since we have such a huge amount of dead marine life in the water”.
She said decaying dead animals in the water were feeding the algal bloom in a “horrible feedback cycle”.
Doubleday likened the algal bloom to a “bushfire underwater” in which the full impacts on marine life were not visible, and called for a national response to the crisis.
A spokesperson for the South Australian department of primary industries and regions said that large swell “in exposed areas of the coastline would lead to increased mixing and agitation”, resulting in more foam or aerosol in areas where the algal bloom was already present.