Didymo Stakeholder Update - 13 September 2007

The purpose of this update is to keep you all informed about the work underway around both the long-term management partnership and the wider didymo response.

Minister to announce more research on chelated copper control tool

The Minister for Biosecurity, Hon Jim Anderton, will announce today the decision that MAF Biosecurity New Zealand will do further research into the use of chelated copper as a potential emergency response control tool for the invasive alga, Didymosphenia geminata (didymo).

Results of field trials of a chelated copper compound (Gemex) earlier this year confirmed it has some potential as an emergency control measure but more research needs to be done about where and when it can be used and any possible effects it may have on non-target species such as molluscs, eels, koura (freshwater crayfish), and other algae.

MAFBNZ believes the chelated copper is likely to be useful only in waterways with low levels of didymo and rivers below a certain size/flow. This targeted research will allow us to make more informed decisions around any possible use of the tool.

The research programme will include:

• Analysis of research to date to identify a list of criteria for assessing where chelated copper could be used to eliminate or control didymo in North Island waterways
• Laboratory trials to assess the impact of chelated copper on selected non-target species. Partners input will be sort to identify relevant species.
• Further monitoring of the Princhester Creek trial site for didymo and assessment of the longer term impacts of chelated copper on the river's ecology

$325,000 has been allocated for the research, which is expected to be completed by June 2008.

Regards
Chris Bicknell
Didymo Response Manager
04 894 0521