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Divers searching for fanworm

Monday, 7 October 2013 4:30 p.m.

Divers from Bay of Plenty Regional Council (BOPRC), University of Waikato and National Institute of Water and Atmospheric Research (NIWA) started searching in Pilot Bay last week, to check for the unwanted pest - Mediterranean fanworm (Sabella spallanzanii). 

The search has been commissioned by BOPRC with support from Ministry for Primary Industries, following confirmation on 20 September that a single specimen of the invasive marine animal had been found in Pilot Bay, Tauranga Harbour.

Approximately one quarter of the search area has been covered so far and no further fanworms have been found to date.

Warwick Murray, General Manager Natural Resource Operations for BOPRC says that the dive survey will give the council a clearer picture of the scale of the problem and the management options. 

"So far we only know of one individual.  By thoroughly searching Pilot Bay and other high risk areas, we’ll find out how numerous and widespread they might be,” Mr Murray said. 

The initial dive survey is expected be completed this month, subject to favourable weather conditions and water clarity.

The divers are methodically searching the highest risk areas of the Tauranga Harbour.   They are visually checking Pilot Bay from the shoreline to the channel edge, including mooring blocks and hulls of moored vessels as well as the reef out to the Tangaroa statue at Stoney Point. High risk sites in the marinas, wharves and port area of the south-eastern end of the harbour are also being checked.

The 5cm long fanworm that was discovered in Pilot Bay is likely to have been spread from the infested hull of a visiting vessel.

“We need boat owners to be vigilant by keeping their anti-fouling paint in good order, and ensuring  their hull is clean before they travel to a new region,” said Mr Murray.

The tube-dwelling Mediterranean fanworm grows up to 40cm in length.  If established, it can grow in dense clumps, competing with native filter-feeders for food and space.  In high densities it is likely to impact on mussels, oysters and scallops.  It can also interfere with boating, aquaculture, and recreational pursuits.

Along with Auckland Harbour, Mediterranean fanworm is also found in Lyttleton and Whangarei Harbours, and was discovered on two barges in Coromandel Harbour earlier this year.

For more on the Mediterranean fanworm, visit or read the factsheet.


Please click on the image below to download a high resolution version (JPEG, 2.27MB)

Mediterranean fanworm

Caption: Mediterranean fanworm (Sabella spallanzanii) in Lyttleton Harbour. Photo credit: G.Read.

Mediterranean fanworm (1)