Marine pest Mediterranean fanworm found outside inner Lyttelton Harbour

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, conducted by the National Institute of Water and Atmospheric Research (NIWA), 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.