Warmer weather brings algal bloom

Published on 17 November 2015

17 November 2015

Warmer temperatures have once again brought about a blue-green algae bloom in Virginia Lake (Lake Rotokawau).

The lake, along with many other New Zealand lakes, has been affected by the bloom in recent years. The bloom brings with it a pungent smell and a very blue/green colouration of the water.

Algal blooms are not uncommon in New Zealand lakes, especially when the weather warms up, and they can come and go throughout the warmer months.

The blooms can recede as fast as they came and there is no knowing how extensive the bloom may become.

Algae occur naturally in New Zealand rivers, lakes and streams. They most often occur in nutrient rich water particularly during warm, calm weather. While most algae are harmless, high levels of blue-green algae may potentially be poisonous.

As a precaution, signs will be erected to warn people of the potential danger around Virginia Lake.

Routine tests will be conducted on water samples to measure the levels of the algal content. Results will be reported back on a weekly basis. As a precautionary measure, people are advised not to make contact with the water.

While dogs are not permitted within the reserve area, people are advised to be particularly vigilant in not letting dogs drink the water as it is potentially harmful.