Kiwi ingenuity brought to bear on marine pests
Didemnum vexillum smothers a
mussel line in Marlborough.
Photo: Ashley Coutts, Cawthron
Institute
Marlborough mussel farmers have been the driving force behind a marine pest management programme in Nelson/Marlborough. Working with a range of stakeholders and local and central government agencies to develop and implement the programme, the mussel farmers have been achieving some notable results.
The marine pest, Didemnum vexillum, is an invasive sea squirt highly adapted to fouling artificial structures, including marine farms. It was introduced into the Marlborough Sounds via an infested barge in 2001 and was immediately recognised as a potential risk to the mussel farming industry.
An attempted eradication programme in 2003, involving the mussel industry, various biosecurity agencies and the Cawthron Institute, proved unsuccessful. It did, however, provide a testing ground for a variety of pest control techniques – experience that would later prove invaluable.
In April 2006, Didemnum vexillum spread on to a mussel farm, settling over and smothering the mussels. The incident renewed concerns within the industry and prompted the establishment of a working group, comprising mussel and salmon farmers, Marlborough District Council, Marlborough Port Authority, Queen Charlotte College, Cawthron Institute and Biosecurity New Zealand (BNZ). The working group was tasked with developing and implementing a pest management plan, with each member contributing funding, expertise and resources.
The plan covers a range of biosecurity activities, including surveillance and monitoring, pest control, managing vectors and pathways, public awareness, research, programme management and review.
Kiwi ingenuity at its best
In the best traditions of kiwi ingenuity, the mussel farmers and service providers applied their marine environment experience to pest control throughout the Marlborough Sounds and Port Tarakohe, Golden Bay. This entailed cleaning some 316 wharf piles, 18 jetties/pontoons, 46 vessel moorings and 27 vessel hulls, some of which were up to 30 metres in length.
In undertaking the cleaning activities, the industry trialled and refined a number of techniques that involved wrapping various structures in plastic and covering the seafloor to kill off fouling pests.
The Minister for Biosecurity approved support for the programme, with a requirement that advances be made available to others. A do-it-yourself guide for the treatment methods applied during the control programme has been commissioned by BNZ. The guide is due to be published in June 2007 and will be available on BNZ's website.
Didemnum Working Group
Environment award recognises success
While the true test of success for the programme will be measured in terms of the reduced impacts caused by the pest, the efforts and achievements of the Didemnum Working Group were recognised when they were awarded the overall supreme and habitat enhancement awards at this year's Marlborough Environment Awards. BNZ congratulates the group for its efforts.
Value of partnerships
A partnership-based approach has helped forge greater cooperation and understanding between the region's biosecurity agencies and marine stakeholders, through a programme that utilises the partners' strengths, interests, expertise and resources.
While the industry focused on pest control, local councils provided support and coordination within their communities. Marlborough District Council provided funding for the programme and engaged with the wider Sounds community, other marine users and industry groups, Port Marlborough, and other local and central government biosecurity
As the geographical scope of the programme has widened to the Nelson region, Tasman District Council has also taken on a support and coordination role, while Nelson City Council and Port Nelson also look set to contribute.
BNZ has provided support and coordination through a communications programme in partnership with the working group, and by funding applied research to deliver pest control and surveillance/monitoring.
The programme continues to demonstrate the value of partnerships to deliver marine biosecurity outcomes, and provides a useful model for future initiatives. It has resulted in an increasing willingness of agencies, industry and other stakeholders to engage and invest resources in the programme, and into marine biosecurity in general. In turn, this has increased the region's marine biosecurity capability.
Future focus on the top of the South
The programme sets the scene for an integrated marine biosecurity programme across the top of the South Island (see separate article on marine pest management partnership in this issue of Biosecurity).
A key point of difference to the Didemnum programme, the Top of the South partnership will take a generic approach to biosecurity risks. The partnership is developing a regional biosecurity plan that will provide a framework for the Didemnun Working Group, and other marine stakeholders, to identify and provide for their broader biosecurity interests in a coordinated manner.
- John Willmer, Senior Adviser Pest Management, phone 894 0238, john.willmer@maf.govt.nz
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Page last updated: 30 April 2008