Action underway against marine pest in Lyttelton Port

22 August 2008

MAF Biosecurity New Zealand (MAFBNZ) is about to test its armoury of marine pest treatment weapons against the introduced Mediterranean fanworm which was recently detected in Lyttelton Port of Christchurch.

The fanworm, an unwanted marine organism with the potential to spread and smother other marine species, was found as part of MAFBNZ’s routine pest surveillance in Lyttelton.

Divers are expected to begin work in the port sometime next week (from 25 August), treating the known populations of the fanworm, while at the same time testing the effectiveness of existing detection and treatment methods for marine pests.

The National Institute of Water and Atmospheric Research (NIWA) is undertaking the work for MAFBNZ and will coordinate a team of divers to undertake thorough searches of the areas of the port known to be infested with the worm and manually remove any specimens they find.

Senior Marine Advisor Dr Peter Stratford says this two-pronged ‘search and remove’ approach has been reviewed and endorsed by an international group of experts including scientists with experience around similar organisms and treatment techniques.

Dr Stratford says MAFBNZ is pleased that the timing of this particular work will enable some measurement of the effectiveness of underwater search procedures and hand-picking.

“Current redevelopment work within the port means a number of wharf piles that may be fanworm-infested are being removed from the water in coming weeks. 

“Divers will go ahead and search and remove specimens, and then once the piles are removed they will be able to be visually inspected onshore, thus allowing a good measure of how effective the treatment has been,” Dr Stratford says.

As well as hand picking, the team working in the port have a second treatment option available – plastic wrapping piles and other underwater structures. This method, which has been used to clean other port areas such as Shakespeare Bay and Bluff, may be used if a dense population is discovered in Lyttelton.

Once the initial work is completed there will be an opportunity to review the information gathered from the treatment activities and determine the longer term viability of the fanworm population and the range of options for continued control in Lyttelton Port.

”What we are hoping to achieve with this exercise is a reduction in the population to a level where successful reproduction is no longer possible,” Peter Stratford says.

MAFBNZ reminds the owners of moored vessels in the area to ensure their boat hulls are clean and well antifouled before moving location. Marine pests like the Mediterranean fanworm can hitchhike to new locations on dirty boat bottoms.

For further information please contact: