Bay of Islands fanworm find sparks vigilance call

29 Sep 2017

Authorities are urging boaties – especially those from or visiting the Bay of Islands –  to be extra vigilant for unwanted marine pests after the discovery of a vessel ‘heavily infested’ with dozens of mature Mediterranean fanworm.

Don McKenzie, Biosecurity Manager for the Northland Regional Council, says officials were alerted to the fanworm after a vessel which had been anchoring at Tapu Point and Matauwhi Bay in the Bay of Islands was slipped at Opua recently.

Mr McKenzie says local Bay of Islands boating clubs and marinas have been notified of the fanworm find and the regional council is considering enforcement action – including a $500 instant fine – over the incident.

“We’re also asking boaties – both locals and visitors alike – to be especially vigilant for fanworm and other unwanted marine pests.”

Ironically, the discovery comes as council contractors prepare to begin their annual Northland-wide hull inspection programme, with more than 2000 hulls expected to be checked over the next few months.

Mr McKenzie says at this stage the council understands the boat involved had been on a mooring at Tapu Point since early July this year and before that had been anchored at Matauwhi Bay.

Council records show the affected vessel was inspected in late 2015 at Otiao Bay (Urupukapuka Island) at which point it did have some hull fouling, but no marine pests were present.

He says the council is organising contractors to survey the mooring area and seafloor where the vessel has been as soon as possible, and given the fanworm discovery, will now also start this year’s wider hull inspection programme there.

He says during the 2015-2016 survey season, six vessels were recorded with fanworm in Matauwhi Bay.

“We did a follow up survey of Matauwhi Bay in late July this year which checked the reef, structures, moorings and adjacent hardstand area where incidents had been recorded, but no fanworm was found.”

Mr McKenzie says pests don’t discriminate when infesting vessels and last season council contractors had checked the hulls of about 1700 vessels covering everything from recreational boats, superyachts and fishing vessels to barges.

He says unfortunately, despite the collective efforts of a range of Northlanders over a number of years, Mediterranean fanworm is now an established pest in Whangarei Harbour.

“No-one wants them spreading any further and with boat owners (both Northlanders and from other regions) now starting to plan their summer excursions, we want to ensure they’re vessels are clear of any marine pests before they move to new areas.”

Mr McKenzie says for some time now most Northland marinas have been requiring a receipt proving a vessel conforms to what’s been dubbed the ‘six or one’ initiative; being either antifouled within six months of leaving a known fanworm-infected area or having undergone a ‘lift and wash’ within one month of leaving an infected area like Auckland.

However, he warns pests can still be concealed in ‘niche areas’ and be missed during antifouling or cleaning.

“Council strongly suggests double-checking areas these niche area; places like the base of the keel, behind anodes, live bait tanks and the bow thrusters before vessels go back in the water.”

Depending on the pests found, owners will be told to haul the vessels out and clean or treat them in what can potentially be a costly process.  A $500 fine may also apply.  More information on marine pests can be found at while the council’s rules and marina requirements can be found at

Meanwhile, Mr McKenzie says regional council staff will also be back out on the water again over summer, talking with vessel owners and making sure they’re aware of Northland’s marine biosecurity and pollution rules.