Marine pest Mediterranean fanworm found outside inner Lyttelton Harbour
Environment Canterbury media release: 4th September 2024
Boaties are being urged to check and clean their hulls to help stop the spread of the marine pest Mediterranean fanworm after it was recently detected in new sites within Whakaraupō Lyttelton Harbour.
A recent winter diving survey was conducted by the National Institute of Water and Atmospheric Research (NIWA) and found fanworm at 38 locations. A small number of fanworm were detected at sites outside the inner harbour including Cass Bay and Corsair Bay. While these were removed by divers at the time, there is a risk that fanworm will continue to spread throughout the harbour.
Team leader central biosecurity and biodiversity Johannes Welsch said marine pests pose a significant risk to coastal marine areas in our region.
“Pests such as Mediterranean fanworm outcompete our native species and can be very difficult to eradicate once they are here,” he said.
“That risk is becoming greater as marine vessel movements start to increase and our waters warm, creating a more hospitable environment to settle,” he added.
We all must play our part in protecting Canterbury’s beautiful waterways and coastal areas because spreading a marine pest comes at a cost.
"The primary pathway that unwanted marine pests are spread is via marine vessel movements. It might seem like a small thing, but when you keep a clean hull, you are protecting our marine biodiversity, our kai moana and our local economy," he said.
"Transporting marine pests has the potential to cost millions of dollars to the taxpayer, ratepayer and affected industries, not to mention the impact on our native species," he said.
Surveillance diving and removal work will be conducted around the harbour before the end of October in collaboration with the Lyttelton Port Company (LPC).
We will also work in partnership with Ngāti Wheke and Biosecurity New Zealand to look at what other approaches can be taken as well as share any data that comes from those surveys undertaken.
What to look out for
- The Mediterranean fanworm is a large worm that has a long, leathery tube that is pale brown in colour.
- The tube is usually fixed to a hard surface and grows up to 100cm in length.
- They have long filaments at the top of the tube that look like a spiral fan, which are either orange, purple or white and banded.
Find out more about the Mediterranean fanworm (Sabella spallanzanii).
Preventing spread of marine pests like Mediterranean fanworm
To help prevent the spread of marine pests and to protect our waterways, please:
- Check your boat hulls for marine pests.
- Book a haulout and clean, if necessary.
Find an approved haulout facility.
- If moving between regions, check regional rules on hull cleaning before you depart.
- When cleaning your hull, do it right. Taking shortcuts can make the problem much worse. You must ensure that no contaminants such as marine pests are discharged into the water during your cleaning process.
Mediterranean fan worm hitchhikes into harbours on boat hulls and grows on jetties and moorings - Northland Regional Council
Report sightings of marine pests
Do not touch or remove any suspected marine pests.
Report the sighting online or call the Biosecurity team on 0800 324 636.
If possible, please take photos and record the location. The location could be the name of a vessel and where it was moored, or the physical location if it was found on the seafloor or structures.