CANBERRA, July 1 (Xinhua) -- A toxic algal bloom off the coast of South Australia (SA) that has caused widespread marine deaths is unlikely to dissipate soon, the state government has said.

The outbreak of the toxic microalgae Karenia mikimotoi linked to a marine heatwave was identified on SA's Fleurieu Peninsula, 80 kilometers south of Adelaide, in March after beachgoers reported experiencing sore eyes, coughing and blurry vision and dead marine creatures washed up in the region.

Since it was discovered, the bloom has spread to Adelaide's suburban beaches and caused the deaths of hundreds of marine species, including sharks, octopuses and penguins.

Experts were initially hopeful that a drop in temperatures over winter would help dissipate the algal bloom but SA's Environment Minister Susan Close said on Monday that it is being very persistent.

She said that new research indicates that the bloom could remain for the next 12 months and is likely to return in the future.

Close said that the bloom, which measured over 4,000 square kilometers in May, has broken up significantly but that much of it has moved to other parts of the SA coast and is continuing to cause marine life deaths.

"We can't control the movement of the Karenia mikimotoi bloom, that's dictated by the way in which the oceans move," she said. "We can't kill it off, simply too much of it is in too much of a large expanse of ocean."

The SA Department for Environment and Water has advised people to avoid swimming or surfing in discolored water, foam or where marine life is dead or in poor health. ■