DATE 31 October 2006
Rangitikei River suspected didymo sample to be analysed
Biosecurity New Zealand is awaiting results of a suspect didymo sample being collected from the Rangitikei River this
morning.
“Biosecurity New Zealand responded immediately yesterday to a call reporting the suspected presence of didymo in the
headwaters of the river. The sample will be sent to NIWA in Christchurch for identification and will be analysed as soon
as it arrives. Biosecurity New Zealand will announce the results as soon as it has them,” biosecurity response manager
David Hayes says.
“As you would expect, we are treating this with urgency, and are working as quickly as we can. However, we do need an
expert to identify this sample microscopically, given that there are several native algaes that look similar to didymo
at various stages. The microscope is the best tool we have at this stage for identifying didymo,” Dr Hayes says.
While there was urgency, confirmation was necessary before any direct action. Several suspect North Island samples
collected in the past had all proven to be other types of alga, Dr Hayes says.
“The Rangitikei River has been in every monitoring survey we’ve run. The last time it was tested was at the end of
August. That included the suspect site and three others upstream. All samples were negative.
“Didymo has not been confirmed in the North Island yet, but every sample like this merely reinforces that the best
defence we have is for personal responsibility and all freshwater users to Check, Clean and Dry between waterways
regardless of where they are in New Zealand.”
So far, 21 South Island rivers have been confirmed as containing didymo, not 30 as has been reported by some media. Most
of the known affected rivers are in the same catchments, or near affected catchments.
MAF Biosecurity is the lead agency for New Zealand’s biosecurity system.
ENDS
To report an exotic pest or disease, call the MAF Emergency Pest and Disease Hotline: 0800 80 99 66.