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More marine pests found in Pilot Bay

Tuesday, 29 October 2013 11:30 a.m.

Divers from Bay of Plenty Regional Council and University of Waikato have found a second Mediterranean fanworm (Sabella spallanzanii) and several clubbed tunicate sea squirts (Styela clava) on the hull of a boat moored in Pilot Bay, Mount Maunganui.

Both the Mediterranean fanworm and clubbed tunicate are unwanted marine animals that have become established in other parts of New Zealand, including in Auckland’s Waitemata Harbour and in Lyttelton Harbour.

“We’ve made contact with the owner of the boat.  He’s very concerned that his boat was hosting these marine pests and has made arrangements to have it hauled out and de-fouled immediately,” Regional Council Natural Resource Operations General Manager Warwick Murray said.

The divers have been searching for Mediterranean fanworms in the southern end of Tauranga Harbour since the discovery of a single specimen in Pilot Bay in late September. Their dive search is now approximately 85 percent complete.

Regional Council and Ministry for Primary Industries (MPI) staff are pleased that only two of the invasive fanworms have been found so far, and that the clubbed tunicate has only been found in one location to date.

“The fanworms that have been found are immature and have not yet had the opportunity to breed.  We’re hopeful that we’ve caught these incursions before they’ve become more widely spread. If they became established in Tauranga Harbour, both of these marine pests could have a negative impact on our kaimoana; including mussels, oysters and scallops. They can interfere with boating, aquaculture and recreational pursuits,” Mr Murray said.

“We need boat owners to be vigilant and make sure they’re not the ones that bring pests into this region. They can do this by keeping their anti-fouling paint in good order, and cleaning their hull regularly, in a place where the de-fouling can be safely captured and contained such as at a haul out facility. That’s especially important before they travel to a new area,” he said.

MPI and the Regional Council are also encouraging boaties to report any unusual sea life by calling the MPI Exotic Pest and Disease Hotline, phone 0800 80 99 66.

“We need to know the location. A specimen or photo is helpful too,” MPI Senior Advisor Kathy Walls said.

Marine pest identification guides are available online at

The dive survey is expected to be completed this month, subject to favourable weather and water clarity. Once the extent of the incursions has been defined, the Regional Council will work with Ministry for Primary Industries to determine the best approach for preventing further spread.


Visit  for more information about the Mediterranean fanworm or clubbed tunicate sea squirt.


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Mediterranean fanworm & sea squirt

Photo caption: Unwanted pests - clubbed tunicate sea squirt (above) and Mediterranen fanworm (below) on the hull of a boat moored at Pilot Bay. Credit Phil Ross.


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 Clubbed tunicate sea squirt styela clava

Photo caption: Close up of a styela clava, clubbed tunicate sea squirt. Credit Northland Regional Council.






Mediterranean fanworm & sea squirt