Lake Ellesmere's water in Canterbury is not fit either for drinking or for recreation as increased concentrations of cynobacteria (blue-green algae) and potential associated toxins has contaminated it very badly.

The outburst of the harmful blue green algae in the vast and shallow lake is monitored by the scientists. They recorded potentially-toxic levels of the same today, according to the Canterbury medical officer of health Ramon Pink.

"Swimmers have been known to develop adverse reactions after bathing and showering in water containing blue-green algal blooms", Dr. Pink said.

The swimmers are suffering from symptoms like eye irritations, rashes and blistering around the mouth and nose, abdominal pain, cramps in body parts, diarrhea, asthma and allergic reactions etc. Fishermen, shooters and swimmers are warned against coming into contact with the water of the intoxicated lake.

Animals may die if they quench their thirst from this toxic source.