The invasive algae didymo has today been confirmed in the Rangitata Diversion Race, MAF Biosecurity New Zealand announced today.
The algae was discovered by local Fish and Game representatives when carrying out routine work. A sample was taken and sent for testing, and later confirmed positive by microscopic identification.
A recent sample taken just below Coal Creek, which is upstream of the Rangitata Diversion Race intake, has tested negative for didymo. Further sampling will be undertaken in the upper Rangitata River and nearby waterways. The diversion race provides water power generation, for stock and irrigation, taking water from the Rangitata River and discharging into the Ashburton, Rakaia and Hinds Rivers. The water race is also used for recreation.
MAF Biosecurity New Zealand didymo response manager Chris Bicknell said “the find is disappointing, and yet another reminder of the need to decontaminate all water equipment when moving between waterways. The Christmas period is especially important as there are many people on holiday using multiple waterways.”
The Peel Forest Enhancement Group is also disappointed with the recent find in their area. They however remain committed to continuing their hard work to protect the upper Rangitata, including maintaining the vehicle washing stations already in place.
The find had increased the potential for river users to spread didymo into other rivers in the region, again highlighting the need for every water user to Check, Clean, Dry their gear between every waterway.
More information on didymo and approved cleaning methods can be found on the MAF Biosecurity website, www.biosecurity.govt.nz .