An algal bloom that can cause illness in humans and be
deadly to dogs has returned to Tomahawk Lagoon in Dunedin.
The Otago Regional Council is warning people to keep children
and dogs out of the potentially toxic water.
Tests results from samples of the thick scum taken on Friday
confirmed the presence of cyanobacteria algae, which could
produce toxins that might cause skin reactions in people and
animals, council engineering, hazards and science director Dr
Gavin Palmer said.
Warning signs had been put up at the lagoon outlet and would
remain in place until further notice, because the scum was
near public access points to Tomahawk Beach.
''We have put up the signs because, while the contaminated
water is relatively shallow, it is still deep enough for
children and dogs to swim in and potentially be at risk if
they do so.''
The algae had been present earlier in summer and then fallen
to very low levels. It was not possible to predict how long
it would take to drop again, he said.
Council staff would continue to monitor the situation and
update the public on developments.
If people saw large amounts of green algae they should
contact the ORC pollution hotline on 0800 800-033.