Marine Pests

Marine pests are most likely to arrive on boat hulls, in ballast water or in water intake systems such as sea chests.

They can also arrive as a result of fishing and harvesting activities or with marine equipment.

Marine pests include:

• Asian clam and Asian date mussel
• Chinese mitten and European shore crabs
• Mediterranean fan worm
• North Pacific sea star
• caulerpa (a green seaweed)
• undaria/wakame (a Japanese seaweed).

What can you do to help?

Boat owners and commercial or recreational fishermen must:

• clean vessel hulls regularly to prevent the introduction of marine pests
• collect and dispose of, on land, any material removed from vessel hulls
• use and effective antifoulant to keep vessels free from fouling organisms
• make sure fishing gear or marine equipment is clean before transporting it to the Chatham Islands
• make sure that if a vessel moves its operational base to the Chatham Islands that it is slipped, cleaned and re-antifouled before relocating
• make sure that if you regularly visit the Chatham Islands that your hull is free of fouling before leaving mainland New Zealand
• avoid, where possible, discharging ballast water in the Chatham Islands that has been loaded in the coastal waters of mainland New Zealand (as long as this is consistent with the safety of the crew and the vessel)
• exchange all ballast water loaded within the territorial waters of a country other than New Zealand in accordance with the Import Health Standard under the Biosecurity Act 1993
• collect a sample of any marine pests mentioned above, place them in a plastic bag, freeze and contact the Ministry for Primary Industries(external link) on 0800 008 333.

For more information on what you can do to help prevent the spread of marine pests, go to our Pest Management page.

If you have seen a pest and are unsure what to do, please contact us.