The cost of fugitive fanworm

A tale of caution for all travelling yachts following a hitchhiking marine pest and a big clean-up bill for ratepayers in Marlborough.

In December 2018 a privately-owned yacht started its journey from the Waitemata Harbour to Waikawa Marina.

The boat was fairly new and had been well maintained and cared for.

But unknown to the owner, Mediterranean fanworm had established itself on the very bottom of the keel bulb – a fact only discovered six months later in May this year when the boat was lifted for a clean at Waikawa.

While the yacht’s infestation was safely dealt with on the hardstand, a search of the marina seabed under the berth found a whopping 165 fanworm.

The good news is that this infestation was contained, and that that no other fanworm were und during a marina wide search, but the bad news is that the surveillance program as a direct result of this one infestation has had to be stepped up considerably and is ongoing.

“For a small council, our fanworm surveillance and response programme is now one of our most costly,” says Biosecurity Manager Jono Underwood. “But we have no option to try and do the best we can given the jewel that is the Marlborough Sounds.” 

Following this incident, another vessel originating from the Waitemata Harbour has also been treated for fanworm.

Just like the Bay of Islands, Great Barrier, the Coromandel and other pristine locations, vessels arriving in Marlborough waters should have no more than a ‘light fouling’ (slime layer) when they arrive. Keeping your antifoul up to date and regular hull cleans are the best way to do this.

https://www.marlborough.govt.nz/environment/biosecurity/marine-biosecurity