Marine pests are one of the biggest threats to the Marlborough Sounds. Two of the most harmful species we’re working hard to keep out are:

• Mediterranean fanworm (Sabella spallanzanii): A fast-spreading fouling organism that forms dense colonies on hulls, ropes, and underwater structures. It competes with native species and disrupts marine ecosystems.
• Exotic Caulerpa: An invasive seaweed that can quickly blanket the seafloor, smothering native habitats and impacting biodiversity. Once established, it’s extremely difficult to eradicate.

These pests hitch rides on boat hulls, in bilge water, and on gear. Once they arrive, they can damage our coastal environment and aquaculture industry. That’s why biosecurity is everyone’s responsibility.

Our Requirements for Visiting Vessels

Mediterranean Fanworm – marinepests.co.nz

If your vessel has visited Lyttelton Harbour/Marina or any port or marina in Tauranga and north in the past 12 months, you must comply with the 6 and 1 Rule before entering our facilities:

• Antifoul or Wash: Your vessel must have been antifouled within the last 6 months or lifted and pressure washed within the last month.
• Provide Evidence: Take photos of your hull before relaunching and keep receipts from haul-out or maintenance contractors.
• Check Thoroughly: Ensure antifouling meets manufacturer specifications and inspect hard-to-reach areas like keel bulbs, props, and water intakes.
• Light Fouling Only: On arrival, your hull should have no more than light fouling (1–5% of visible hull surface covered by macrofouling or algae, with the rest as slime).

Every berth holder can help protect our bays and harbours by following these good practices:

• Lift and wash your vessel after short stays in high-risk areas.
• Keep your hull clean including under the keel.
• Antifoul regularly.
  

  Exotic Caulerpa – NIWA

• Check anchors, chains, dive gear, and fishing gear before moving locations.
• Report fouled vessels or suspected marine pests to biosecurity@marlborough.govt.nz or call MPI on 0800 809 966.

A clean hull isn’t just good for the environment—it improves fuel efficiency and performance. Plus, compliance with these rules helps us maintain our Clean Marina accreditation and ensures Marlborough remains a world-class boating destination.

Have questions or need advice? Talk to your friendly marina team—we’re here to help.