“A horror film”: sharks and squids under 200 species killed by poisonous algae in front of South Australia

More than 200 types of sea, including deep water sharks, leaf blades and inkfish, were killed by a toxic algae blossom that has been affected by the coast of South Australia since March.

Almost half (47%) of the dead species were ray-fining fish and a quarter (26%) were sharks and rays. According to the Ozfish analysis of 1,400 reports on citizen scientists.

Cephalopods – such as inkfish, inkfish and ink fish – made 7%, while decapodes – such as crabs, lobster and shrimp – made 6% of the species that were dead or rinsed on the beaches.

Ozfish South Australian project manager from Ozfish, Brad Martin, said the harmful bloom – of Karenia Mikimotoi Algae – was like a poisonous ceiling that suffocated the sea life.

“It can require fish from their gills to cause bleeding by attacking their red blood cells and act as a neurotoxin and attack the fish's nervous system and brain, which causes unusual behavior,” he said.

“That is why some fish and sharks act so strange and why many of the dead have a red shimmer – it's like a horror film for fish.”

According to the state's environmental department, the algae blossom was driven by a running marine heat wave – with 2.5 ° C water temperatures – and relatively calm sea conditions with little wind and small swelling.

Although the algae are not toxic for humans, the algae could cause skin irritation and breath symptoms and cause mass mortality in marine life.

The algae were first identified on the Fleurieu Peninsula in the state in mid-March and have been expanding to the coasts in the southeast of the Gulf St. Vincent, the Yorke Peninsula and the island of Kangaroo said Martin.

Ozfish, an organization that devoted itself to the restoration of waterways and fish rooms, was concerned about the long-term effects on fishing, since the flower had killed fish in all age groups-from fingerlings or baby fishing up to adult breeding fish and their food sources.

Several oyster farms and the commercial harvest of Pipis were temporarily closed due to the outbreak that was unprecedented for South Australia, said his Environment Minister Susan Close.

“We speak of a very large algae blossom with a significant influence on the sea life,” she said, with some parts of the outbreak being 20 meters deep.

The marine biologist Prof. Shauna Murray from the University of Technology Sydney, who identified the algae under the microscope and analyzed its DNA, said that there were about 100 types of harmful algae with a different toxic effect.

Although still not well understood Karenia Mikimotoi It was assumed that it was generating a reactive oxygen that caused damage to gill cells when it was fish – which meant that they could not breathe, said Murray.

While the current flower stretched over 150 km, it was not the worst in the history of Australia. In 2013 a blossom of another species, Alexandrium Catenellahad “basically covered the entire east coast of Tasmania and closed its aquaculture and seafood industry for about four months,” she said.

Large flowers could also reduce the amount of oxygen in the water, said Prof. Martina Doblin, a UTS -Oceanographer who specializes in algae flowers.

Karenia Mikimotoi Is an unusual algae that could feed on both sunlight and other organisms, she said. And these properties are combined with unusually high and stable water temperatures that made it possible for the algae to become so large and persistent.

“In a low abundance, it is part of the natural food network. However, it can be very problematic in high frequency,” said Doblin.

While such events were rare, they can be devastating for the local economy, she said. Improved early warning systems and management had the potential to limit the damage.

According to a spokesman for the environmental department of SA, strong western winds were ultimately needed to dissolve the algae. “However, persistent high -pressure systems that affect South Australia have delayed these winds,” she said.