Divers resume boat hull checks for marine pests

An estimated 1500 boat hulls will be checked by divers between now and mid-May next year for marine pests such as Mediterranean fanworm, which threaten the region's precious marine environment.

Regional council biosecurity officer Irene Middleton says Northland-based dive contractors Marine Environmental Field Services kicked off the 2016-17 inspection programme in Whangarei Harbour yesterday.

"Boat owners will be starting to plan their summer excursions and we want to ensure they're clear of any marine pests before they move to new areas."

"These pests don't discriminate when infesting vessels and last season our contractors checked the hulls of about 1000 vessels covering everything from recreational boats, superyachts and fishing vessels to barges."

Ms Middleton says despite the collective efforts of a range of Northlanders, Mediterranean fanworm is unfortunately now established in Whangarei Harbour, prompting the council to warn vessels travelling from this area to be extra vigilant.

"Whangarei boats will find they receive the same scrutiny as visitors from Auckland, which has had a well-established fanworm population for a number of years."

She says marinas in Northland have been very supportive of efforts to keep unwanted marine pests out of the region – implementing their own tougher entry criteria in recent years – and have this year been added into the dive inspection programme.

"Marina operators have already 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, some vessels which have adhered to the recommended 'six or one' messaging had still seen fanworm surviving in 'niche' areas anti-foul had not reached.

"Pests can still be concealed in these niche areas and be missed during antifouling or cleaning. Council strongly suggests double-checking areas like the base of the keel, behind anodes, and the bow thrusters before vessels go back in the water."

Depending on the pests found, owners will be asked 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 the council’s rules and marina requirements can be found at www.nrc.govt.nz/visitingboats

Meanwhile, Ms Middleton says as well as checking hulls for specific marine pests, the contract divers will also be paying attention to the general cleanliness of hulls in the region as part of research into a new Marine Pathways Management Plan the council is developing.

“The new pathways plan is scheduled to be made available for public consultation in February, with rules limiting the amount of biofouling permitted on hulls under consideration.”

She 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.