Blue Green Algae Spotted in Wetlands Near Pegasus Lake

Published: 02-Dec-2019

Residents who walk or bike in the marsh areas surrounding Pegasus may notice signage which has gone up this week alerting them to blue green algal blooms.

The area in question is the natural wetlands between Pegasus and the TÅ«haitara Coastal Park – beside the access road and near bike and walking paths.

Click on the image to the right for a better view of the location.

This part of Pegasus isn’t used for swimming but there is a risk that dogs may enter the water if being walked off a lead.

Pegasus Lake itself is not affected by this bloom and there is no risk that this bloom will spread to the lake.

Waimakariri District Council have put up some precautionary signage to alert people who use the area primarily to keep their dogs on a lead as the algae (which is technically called cyanobacteria) can be harmful if swallowed.

Pets should be taken to a vet immediately if they are showing signs of illness after coming into contact with algal mats.

Facts about cyanobacteria:

  • The algae occur naturally but can increase rapidly during warmer months.
  • If the water is cloudy, discoloured, or has small globules suspended in it, avoid all contact.
  • Not all cyanobacterial blooms are visible to the naked eye and toxins can persist after the blooms disappear.
  • Cyanobacterial concentrations can change quickly with changing environmental conditions (e.g. wind). If a health warning is in place avoid contact with the water.

Algal blooms occur naturally during warmer months and aren’t uncommon in areas where water levels are low or not flowing at a fast rate.