Duck shooters, particularly those with dogs, should be vigilant about toxic algae in rivers, Environment Southland said today. The duck shooting season opens this weekend.

Environment Southland’s director of science and information, Graham Sevicke-Jones, said warnings about increased increased amounts of toxic algae (cyanobacteria) in several rivers were in place until last week. With the exception of the Mataura River at Mataura Island, all warnings had been lifted. “However, Environment Southland’s monitoring does not cover all reaches of all rivers,” he said, “so extra awareness is needed.”

“People and animals, in particular dogs, should avoid contact with cyanobacteria mats, which can accumulate on the sides of rivers,” Mr Sevicke-Jones said. “Eating just a small amount can be very harmful to dogs.” Toxic algae usually occur as dark brown/black mats which become attached to rocks in rivers or accumulate on the surface in shallow, slow-flowing areas. They often have a strong musty smell.

If you experience health symptoms after contact with contaminated water, visit a doctor immediately. Animals that consume cyanobacteria should be taken to a vet immediately.