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14 June 2010
MAF Biosecurity New Zealand's (MAFBNZ) programme to rid New Zealand waters of
the introduced marine pest the Mediterranean fanworm (Sabella spallanzanii)
has been called off, with new information showing the pest is too widespread to
The Mediterranean fanworm is what's known as a fouling pest. It can form
dense populations, potentially smothering other native marine species and
altering underwater ecosystems.
The fanworm was first detected in Lyttelton Port in March 2008, and with no
other known populations at the time, Government funded a $3.5 million treatment
programme to attempt to eliminate it from the port. The programme involved
searching for and manually removing all specimens found.
In August 2009 a further small population of the fanworm was detected in
Auckland's Viaduct Basin - five individuals on wharf structures and a heavy
infestation on a barge tied up in the area. MAFBNZ decided to treat the area,
including the barge, as a part of the existing programme. In January this year,
however, a much larger and well established infestation was found in a number of
locations in the wider Waitemata Harbour.
The chair of MAFBNZ's Response Strategic Leadership Team for the fanworm
programme, Dr Doug Lush, says it is disappointing, but the scale of the
Waitemata infestation means that elimination of the fanworm from New Zealand is
no longer feasible.
"We looked at a number of possible options but in the end, continuing to fund
this effort did not add up given the geographical spread of the pest and the
high cost of what is a very intensive process to remove them. The Government
has, therefore, determined that the response to the Mediterranean fanworm be
stood down" Dr Lush says.
"All operations in Lyttelton Port and the Waitemata Harbour will now cease
and MAFBNZ will continue to work on addressing the means of marine pest
introduction and spread generally, rather than focus on one specific species."
Dr Lush says the decision is no reflection on the effectiveness of the
Lyttelton programme. Regular checks as part of the effort showed that in the two
years of treatment, the population there had been significantly reduced by the
treatment. As well, the programme, which had cost $1.3 million to date, had
demonstrated that where there are limited populations of some marine pests in
confined locations, the 'search and remove' technique is likely to be an
"It's important to note that the closure of the fanworm elimination programme
in no way rules out action against introduced marine pests in the future, but it
recognises that once an organism is well established in the marine environment,
it is very difficult to eliminate it.
"Boat owners and operators also have a role to play in limiting the further
spread of the Mediterranean fanworm, and other fouling pests like it, around New
Zealand's coastline," he says.
"These kinds of pests attach to boat hulls and can be transported from
location to location. Vessel owners can avoid this by keeping their boat bottoms
clean and their antifouling paint up to date and thoroughly applied."
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