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Marine pests are a huge threat
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Like possums and stoats on land, these guys have huge potential to wreak havoc on our native marine life. Let's keep them out of the beautiful Bay of Islands!

Marine pests are a huge threat

Quick Facts

fanworm opuaFanworm on boat hull. Photo: Northland Regional Council

"Marine invaders are one of the great threats to the world’s oceans, arguably more sinister than land-based pests".

  • There hasn’t yet been complete eradication of a single marine pest in New Zealand.
  • Marine invaders are typically difficult to detect and monitor.
  • They are usually fast growing, breed prolifically, can survive all sorts of environmental conditions, and have few natural predators.
  • Some are highly competitive, displacing native plants and animals. Others alter the underwater seascape and change the way ecosystems function.

Download MPI's excellent marine pest ID guide here

Below are nine of the alien species not known to have established in the Bay of Islands - but which we should be most concerned about.

If you suspect you have found any of these species in the Bay of Islands, or elsewhere in Northland, put a sample into a plastic bag, place in fridge, and contact Northland Regional Council (0800 504 639) or Ministry for Primary Industries (0800 80 99 66)

undariaUndaria seaweed (Undaria pinnatifida) Photo: Northland Regional Council Caulerpa seaweedCaulerpa seaweed (Caulerpa taxifolia) Photo: Northland Regional Council Mediterranean fanwormMediterranean fanworm (Sabella spallanzanii) Photo: Northland Regional Council

asian clamAsian clam (Potamocorbula amurensis) Photo: Northland Regional Council seastarNorthern Pacific seastar (Asterias amurensis) Photo: Northland Regional Council sea squirtPyura sea squirt (Pyura stolonifera praeputialis) Photo: Northland Regional Council

asian paddle crab Asian paddle crab (Charybdis japonica) Photo: Northland Regional Council mitten crab Chinese mitten crab (Eriocheir sinensis) Photo: Northland Regional Council european shore crabEuropean shore crab (Carcinus maenas) Photo: Northland Regional Council


What we can do to avoid spreading marine pests
  • arethusaPhoto: Dean WrightRegularly cleaning your boat’s hull – ideally keep fouling growth to no more than a light slime layer.
  • Applying good thorough coatings of antifouling paint and keep it in good condition
  • Ensuring your hull is clean and free of fouling before you travel to a new region
  • Cleaning and drying any marine equipment (e.g. ropes, lines, pots) before using in a new location.
  • Inspecting areas on your boat that retain water in case they’re harbouring marine life.
  • Checking anchors, trailers and other equipment for tangled weeds.


Join Fish Forever

nudi spongeAll of us with an interest and love of Tangaroa, let's work together and take on the challenge of marine protection for the Bay.

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Student/concession - $15.00
Affiliate (please name organistation) - $15.00
Individual - $25.00
Family - $35.00

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