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Regional Council gains new tool to tackle marine pests

Tuesday, 16 June 2015 10:00 a.m.

Bay of Plenty Regional Council has gained new powers to manage marine pests in the Bay of Plenty. It has declared two Small Scale Management Programmes to control and prevent the spread of the unwanted marine pests Mediterranean fanworm (Sabella spallanzanii) and clubbed tunicate sea squirt (Styela clava).

It’s the first time in the country that a local authority has used the Small Scale Management Programme provisions of the Biosecurity Act to deal with a new marine pest threat. Marine pests are a problem because of their invasive growth and feeding habits which can impact on marine-based business, recreation, marine ecology and kaimoana (seafood) stocks.

The Programmes give warranted Regional Council Biosecurity staff legal powers, such as to enter and inspect marinas and wharves, or direct owners to haul out and clean their boats, if necessary.

“To stop new pests from establishing here, we need to remove them as soon as they’re detected, before they can spawn or spread further. We’ll always try and collaborate with a boat or structure owner in the first instance. The powers are only there for when people aren’t co-operating or can’t be contacted,” said Regional Council Biosecurity Officer Hamish Lass.

“A single Mediterranean fanworm was first found in Tauranga Harbour in September 2013. Thanks to help from Ministry for Primary Industries and University of Waikato we’ve now got a thorough marine pest surveillance programme in place.”

“High risk sites are checked twice yearly and 38 hotspots where pests have previously been found are checked monthly. That means regular dive surveys of more than 450 moorings, 800 boat hulls, 10 kilometres of marina pontoons and 1.5 kilometres of rock walls,” Mr Lass said.

In the past two years, six recreational boats moored in Tauranga Harbour have been found with the unwanted pests growing on their hulls. Five of the boats had recently travelled from parts of Auckland or Northland which are already infested. The infestation source of the sixth boat is currently being investigated.

“We’ve relied on co-operation from boat owners to get the boats hauled out and cleaned. That’s worked so far, but without enforcement powers there’s been potential for our response to be delayed or ineffective.”

“The high volume of recreational boating traffic in and out of the Tauranga Harbour means there’s a high risk of more pest infested boats arriving in the Bay of Plenty. The biggest problem is boats that have been moored in infested areas and then sailed here without prior checking and cleaning of their hulls. Regular cleaning and anti-foul application is something every moored boat owner can do, to help prevent the spread of marine pests,” said Mr Lass.

Tips for boat owners and more information about marine pests and the new Small Scale Management Programmes is available at

Mediterranean fanworm (1)