Can the cold snap hitting SA blast the toxic algae bloom?

Damaging winds and high swells are expected to lash the state this week. But what does that mean for the algae bloom crisis that has hit our marine environment?

The toxic algal bloom that covered parts of SA’s coast, killing marine life and making surfers sick, could be slowed down by the winter weather currently blasting the state.

Higher-than-usual marine temperatures, recorded since last September, have been considered a contributing factor to the Karenia mikimotoi algae bloom, which was “roughly the size of Kangaroo Island and up to 20m deep”, according to Environment Minister Susan Close.

But a new report from the Department of Primary Industries (PIRSA) revealed seasonal cooling of waters is continuing across the state.

The report, released this month, expected waters would continue to cool until mid-August.

Marine creatures including hundreds of fish have died, after severe weather conditions that impacted the southeastern coastline caused an algal species, Karenia mikimotoi to bloom in the Coorong.

But Victor Harbor fisherman, Rod Ness, 69, said he’s was unsure if the damage caused by the bloom could be undone.

“The authorities said months ago, when we get the (cooler) weather and rougher conditions, it will clear – and they were probably right,” he said.

“But we haven’t had that up till now … I don’t think has done what it was supposed to do to the extent they thought it might.

“The massive damage is already done. And I don’t know where that’s going to go for the future.”

Mr Ness had to make the difficult decision to stop chartering his fleet boats back in March, after uncertainties rose around the toxicity of the bloom.

“My duty of care says I’m not taking those people out for their safety purposes,” he said.

“If I can’t take them out and catch fish that I know are suitable to be eaten, or I’m not going to jeopardise their health, then I’m not going to charter”.

Not-for-profit, OzFish, had reported more than 200 species had fallen victim to the ‘toxic blanket’ and smothered sea life on the shoreline since February.

Dead sea life from algal blooms at Foul Bay, Yorke Peninsula. Picture: Stefan Andrews courtesy Great Southern Reef Foundation

A PIRSA spokesperson said the “current expectations are that colder water temperatures will slow the growth of the algae.”

“Typical winter wind periods of moderate to strong west to south-westerly winds, are expected to increase the flushing of coastal waters, in particular around Gulf St Vincent and the Fleurieu Peninsula, with oceanic waters,” the spokesperson said.

“This is also expected to also assist in reducing the presence of the harmful algal bloom.”

A cold, windy front is expected to envelope South Australia for the rest of the week, with renewed promise of dispersing the bloom even further and cooling sea temperatures.

Bureau of Meteorology meteorologist Jon Fischer said to expected elevated sea levels and big waves over the first half of the week.

“We’re likely to see some quite large waves through those offshore coastal areas, so outside of the gulfs, even peaking around seven to eight metres,” Mr Fischer said.

“Inside the gulfs we are likely to see some quite rough seas and also elevated sea levels as we move through, particularly Tuesday afternoon and evening around the high tide.”

Mr Fischer said that while a coastal hazard warning had been issued, sea levels during this event were unlikely to be as high as during similar weather at the end of May.

“We’re still likely to see some coastal impacts and potentially some flooding of low-lying areas from that seawater.”

Originally published as Can the cold snap hitting SA blast the toxic algae bloom?