Reduced Karenia detection in SA waters with ‘promising’ summer on the horizon
After a month of wild weather, there are hints that the worst of the algal bloom could be behind us. But a leading scientist warns something else could be taking its place.
A highly toxic algae species could disappear from South Australian waters if the weather heats up, but that doesn’t mean the bloom will be gone for good.
Karenia cristata – the species that’s caused mass fish kills, dolphin deaths, and serious health symptoms in beachgoers – has a “propensity” for cooler water and while SARDI’s executive director Mike Steer said information on the species was “relatively immature”, it was “promising” if there was a warmer summer.
However, he said “we just need to be cautious” that one of the four other Karenia species in SA waters – Karenia brevisulcata, Karenia mikimotoi, Karenia longicanalis, and Karenia papilionacea – didn’t become dominant in the warm conditions.
“They may prefer warmer water,” he said.
“It would mean that the algae (bloom) would persist.
“But the interesting thing about those different species is they don’t all produce the same types of biotoxins (that Karenia cristata does).”
Results from the beginning of this week show 18 of the 21 metropolitan onshore testing sites have no or low levels of Karenia species.
West Beach Boat Ramp, Grange Jetty and Henley Beach Jetty are the only three metro sites recording elevated levels with 12,000 cells per litre, 110,000 cells per litre, and 240,000 cells per litre respectively.
Mr Steer and Environment and Water Minister Lucy Hood said the public didn’t need to be alarmed over increased sea foam sightings in recent weeks, the minister calling it “blow-vember”.
The increased “thick” foam was attributable to more plant matter — and more specifically, algae — in the water, Mr Steer said, and both plant matter and algae are declining.
“Inevitably, the ecosystem will rebalance,” Mr Steer said.
