Didymo threat to hydro power

Fears are growing that the rampant spread of didymo could affect electricity supplies, after Biosecurity New Zealand has found proof the invasive algae can grow in lakes.

It was initially thought didymosphenia geminata would not survive in still water.

The weed has been spotted as far south as Cromwell in Lake Dunstan.

Overseas hydroelectric power schemes have been affected by large didymo blooms blocking water intakes.

Contact Energy, which operates the Clyde dam on Lake Dunstan, and Meridian Energy are both watching the didymo situation.

Meridian stopped taking water from the affected Mararoa River into the Manapouri scheme some time ago.

Biosecurity New Zealand spokeswoman Tina Nixon said the algae had also been found in microscopic form in Lake Manapouri. While the algae only survived on the edge of lakes, this was where most people concentrated their activities, she said.

Didymo can attach itself to anything, including boats and fishing equipment.

- NZPA