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Hopping mad over fanworm risk to Whangamata harbour

Published: 2018-03-28

An Auckland boatie keen to attend Beach Hop was turned home last week after hundreds of the devastating aquatic pest, Mediterranean fanworm, were found on the hull of his vessel moored in Whangamata harbour.

Mediterranean fanworm, also known as ‘Sabella’, is an invasive tubeworm that can establish in large colonies and will outcompete native species, such as mussels and scallops, for food and space.

So far it is only in a few New Zealand harbours and in the Waikato region it’s been limited to Coromandel Harbour. Waikato’s harbour surveillance programme using Bay of Plenty Regional Council’s dive team has been targeting popular boating havens for signs of fanworm.

The team was in Whangamata last Wednesday and discovered the fanworms on the hull of the Auckland-based vessel, which had only arrived in the harbour that morning.

“It’s just luck that we had a dive team in the harbour at the time the vessel arrived and once we established it had sailed from Auckland – where fanworm is well established – they were able to inspect its hull,” said Waikato Regional Council biosecurity pest animals team leader, Brett Bailey.

“Unfortunately the vessel was too large to be pulled from the water, so the owner agreed to leave the harbour and return to Auckland, which meant he missed Beach Hop.”

Mr Bailey said it had put the harbour at risk. “It’s possible some fanworms may have fallen off the boat’s hull while it was moored in the harbour. Because there’s the potential for a new incursion, we contacted the Ministry for Primary Industries who agreed to provide support. The plan is to have a team of divers survey the harbour next week.

“Boaties can reduce the risk of picking up and spreading fanworm and other marine pests by ensuring their hulls are clean and anti-fouling is up-to-date,” Mr Bailey said.

He urged boaties to be diligent and report sightings of fanworm by calling the council’s biosecurity team on 0800 800 401, or the MPI Pest and Diseases hotline on 0800 80 99 66.

Because the owner agreed to sail his boat back to Auckland as soon as possible and understood the need to keep his hull clean of marine pests, the council and MPI are satisfied that this served as a warning to the owner and no further action will be taken.

People wanting more information on fanworm should visit Advice on good vessel hygiene is also available at