Marine pest found at Waitangi Wharf

The Environment Canterbury dive team has been removing a marine pest called undaria which was discovered recently at Waitangi Wharf.

Undaria is an Asian kelp native to Japan, which can form dense colonies that displace native plant and animal species. Although reasonably widespread across New Zealand waters, the Chathams only had one site at Port Hutt containing the marine pest until it was discovered at Waitangi Wharf.

To try to eradicate the kelp at Waitangi Wharf, the dive team has been busy removing the plants from the area and dumping kina onto the site. Kina are a natural control agent of undaria and it is hoped that this will help to control the pest.

Undaria’s preferred habitat is intertidal waters to a depth of 40m and grows on any hard surface including wharf piles, pontoons and buoys, rocky coasts and reefs as well as boat hulls.

How can you help contain the spread?

As Undaria is mainly spread by fouling on boat hulls, it’s important to regularly clean your boat hull to ensure it is free of fouling before you travel to a new area. You should also clean and dry any marine equipment (e.g. pots, lines and ropes) before using again in a new area.

If you see any undaria while in or on the water, please contact Environment Canterbury biosecurity officer Robin Seymour on 03 305 0033.

Undaria collected from the Waitangi Wharf area

Loading undaria onto the boat