Environment Southland is urging the public to remain vigilant for toxic algae in waterways.
The Mataura River, which had a toxic algae scare late last year, has now had the alert removed.
However, toxic algae has recently been reported at The Reservoir in Curio Bay, the Aparima River near Thornbury and the Mararoa River near Waianiwa.
Environment Southland’s Director of Science and Information Graham Sevicke-Jones said it was important to remain vigilant when around water.
It was important to know what to look for when around water to avoid getting sick, he said.
“We all need to be aware of the bacteria which can be present on our water that can make us sick,” Mr Sevicke-Jones said.
‘The public need to keep a close eye out for this algae at rivers, which appears as a green or brown slime on rocks, or dry brown or black mats at a river’s edge,” he said.
“This algae produces toxins that can be harmful to people and animals if swallowed, or through contact with skin.”
Dog owners should be extra cautious around the water, Mr Sevicke-Jones said.
Environment Southland monitors water in the region, checking bacteria levels every week, although the test did not pick up on the toxic algae, he said.
“We also monitor for toxic algae too, which isn’t to be confused with the microbial bacteria we test for which enters waterways via faecal material from human and animal waste or run-off.”
The algae is most commonly detected by eye, he said.