Biosecurity New Zealand and aquaculture industry collaborate to combat pest
14 August 2006
Biosecurity New Zealand and a combined Marlborough-based industry and council group will be working together to help fight the marine pest Didemnum vexillum.
The Minister of Agriculture, Hon. Jim Anderton has allowed for the redirection of some existing biosecurity budget (up to $150,000) to support the aquaculture sector with initiatives to contain the spread of the organism in the Marlborough area.
Didemnum vexillum is a species of sea squirt, although different to the Styela clava sea squirt that has been the target of a biosecurity response since mid-2005. Didemnum has been present in pockets in the Sounds since 2001 but has flared this year. It has the potential to smother mussel lines and impact severely on the Marlborough mussel farming industry.
Biosecurity New Zealand’s Manager of Pest Management, Andrew Harrison, says he has been impressed with the working group’s development of a comprehensive management strategy and actions aimed at reducing the risk Didemnum poses to the Nelson-Marlborough mussel farming sector.
“We are very pleased to be able to contribute to the plan, providing technical expertise in the areas of public awareness and communications activities and applied research into response and surveillance activities,” Andrew Harrison says.
“The industry and Marlborough District Council have taken an appropriate lead and responsible steps in dealing with this pest. The commitment and the activities they have undertaken are cutting edge and a good example of the sort of cooperation and innovation Biosecurity New Zealand wants to support and promote in future. We look forward to collaborating with the Marlborough working group and work will begin immediately.”
Working group chairman Graeme Coates of the New Zealand Marine Farming Association based in Blenheim says it has been particularly gratifying to work alongside other members of the working group which comprises marine farmers, the Marlborough District Council, Port Marlborough and now Biosecurity New Zealand. The local area office of the Dept of Conservation will also be providing support in kind over the coming years.
“Since April 2006, when the group first met, it has been working hard to clean up areas of infestation before the spawning season starts in September,” Graeme Coates says.
“Over 12 affected sites have now had primary eradication efforts where an infected structure or vessel is either removed from the water for 24 hours or wrapped in plastic to prevent the organism feeding.
This clean up work is expected to continue for a further two weeks and initial results look very promising.”
Overall, both Biosecurity New Zealand and the working group emphasise that containing Didemnum will require the support of the wider Sounds community as well as boating and marine industries in the Sounds. Ensuring vessel hulls are free of fouling and painted with anti-foul where appropriate will help prevent the organism’s spread. Jetties are also prime habitat for Didemnum and owners will be asked to check these over the summer months.
For further information on Didemnum or to report a suspected find, please phone the working group on 0800 4 debris (0800 4332747).
Didemnum is a leathery light mustard coloured sea squirt which presents like a yellowish wax dripping over a structure such as a rope or mussel line.
Contact Details:
Andrew Harrison, Pest Management Group Manager, Biosecurity New Zealand
Ph: 04 894 0524 or 029 464 5454
Lesley Patston, Communications Adviser, Biosecurity New Zealand
Ph: 04 894 0163 or 029 894 0163
Graeme Coates, NZ Marine Farming Association and Chair of Didemnum Working Group
Ph. 03 578 5044 or 027 445 4389


