With an ability to pack in 1,000 individuals per square meter, Mediterranean fanworm makes it difficult for other species in the vicinity to survive. Imagine it doing that in some of our pristine dive spots. It filters large volumes of water, feeding on nutrients and plankton, including the larvae of our much loved recreational fish species. Large numbers attached to your hull could be costing you a whole heap more in fuel too.

How to identify Mediterranean fanworm:

• Fan often orange-yellow with bands of purple, white, yellow and brown

• Fan spirals out from tube in single crown

• Tubes are tough, leathery and flexible

• Tubes often 10-120 cm but can be bigger!

• Attaches to any hard surfaces

This species is known to be in the following locations in Northland, Auckland, Coromandel (western side), Canterbury, , Gisborne. If you find it outside this area, please report it.

Whangaroa Harbour, Opua, Whangārei Harbour, Hauraki Gulf including Waitematā Harbour and Firth of Thames,  Port Fitzroy area and Wairahi Arm Aotea / Great Barrier Is, western side of Coromandel Peninsula and Square Top Island, Lyttelton Harbour.

This list is correct to the best of our knowledge at the time of publishing - for a full list of marine pest locations, please go to the Marine Biosecurity Porthole If you find it outside this area, please report it.