Biofouling management

Marine pests and diseases introduced to New Zealand on vessel hulls (biofouling) are a threat to our marine environment and resources. All vessels arriving in New Zealand must provide evidence of biofouling management prior to arrival.


Ensure you have a clean hull before your vessel leaves for New Zealand

A clean hull may reduce any additional biosecurity-related costs and delays, should unforeseen itinerary disruptions occur.

  1. Get ahead of your biofouling: organise an underwater inspection and act on all biofouling found.
  2. Ensure that your most recent underwater inspection or underwater cleaning report is supplied to MPI.
  3. Ensure that all other relevant paperwork is supplied to MPI.
  4. Let MPI know as soon as a delay becomes likely.
  5. Reach out to MPI prior to departure for New Zealand if you are unsure of whether to carry out biofouling, or to seek further advice.

Following these 5 steps improves the likelihood of MPI granting a request to extend your itinerary. 

Port congestion: Vessel delays – suggested steps to take before coming to New Zealand [PDF, 360 KB]

If you have any questions, email:, or 

Biosecurity New Zealand's vessel biofouling survey

Biosecurity New Zealand has organised a survey of biofouling which will begin in August. Hull checks will be required for up to 40 cargo vessels arriving in New Zealand.

Ships will be randomly selected to take part. A dive inspection will check the ship's hull, and the crew will need to answer a questionnaire about biofouling.

The survey will identify the types of vessels that are most likely to be contaminated with foreign marine species. This will help Biosecurity New Zealand to target vessels that need further investigation.

See the media release

Find out more about the project in our frequently asked questions document.

Frequently asked questions (FAQ) [PDF, 587 KB]

See an example of the questionnaire selected vessels will be sent.

Overview of vessel biofouling survey questionnaire [PDF, 282 KB]

New Zealand's biofouling requirements

All vessels must provide evidence of biofouling management before they arrive in New Zealand.

The Craft Risk Management Standard (CRMS) for Biofouling outlines the requirements for international vessels.

More information on how to meet the requirements is available in our:

Two vessel categories under the CRMS

Vessels are sorted into 2 different categories based on their intended stay in New Zealand.

  • Short-stay vessels – those staying in New Zealand for less than 21 days, and only visiting approved places of first arrival.
  • Long-stay vessels – those staying 21 days or longer, or visiting areas not approved as places of first arrival.

Most short-stay vessels are commercial vessels, including:

  • tankers
  • bulkers
  • container ships
  • commercial cargo vessels.

Long-stay vessels often include:

  • yachts and other recreational vessels
  • cruise vessels
  • work and project vessels
  • research vessels
  • defence vessels.

How to comply with the requirements

You'll be able to meet the biofouling requirements by doing one of the following (and having documentation to prove it):

  • Undertaking continual hull maintenance using best practices (recommended for short-stay vessels).
  • Cleaning the hull and niche areas within 30 days before arrival in New Zealand (recommended for long-stay vessels).
  • Booking an appointment for the vessel to be hauled out and cleaned by an MPI-approved treatment supplier within 24 hours of arrival (recommended for vessels coming to New Zealand for refit or repair).

If your vessel can't meet the standard using one of these measures, you may develop a craft risk management plan that details alternate but equivalent measures to manage biofouling.

Craft risk management plans

If your vessel can't meet the CRMS requirements using one of the 3 options, you may develop a craft risk management plan that outlines alternate but equivalent ways of managing biofouling. Craft risk management plans must:

  • be approved by MPI
  • include steps to reduce risk to the equivalent level of arriving with a clean hull.

Application form and guidance for developing a craft risk management plan [PDF, 949 KB]

If you are interested in developing a craft risk management plan, for more information please contact

Providing evidence of compliance

Before you arrive, MPI will ask to see evidence that you've undertaken one of the 3 measures listed above. Evidence must be verifiable, and may include:

  • your biofouling management plan and record book
  • dates and reports of dry docking
  • current antifouling certificates
  • vessel operational history
  • evidence of independent inspections and ongoing maintenance (such as cleaning or treatment) by suitably qualified people.

If you plan to submit a dive inspection report as evidence of hull maintenance, check MPI's guidelines for diving service providers (below). These outline what should be in a hull inspection report, and give examples of allowable biofouling (for short-stay vessels).

Diving inspections of vessels arriving to New Zealand [PDF, 2 MB]

Evidence requirements - Dive inspection template [DOCX, 170 KB]

Continual maintenance using best practices

For short-stay vessels, the recommended option is to demonstrate continual hull maintenance using best practice. Best practice involves ongoing management of biofouling, including:

  • applying an antifouling paint on the hull and niche areas
  • developing, maintaining, and following a biofouling management plan
  • keeping records of maintenance activities in a biofouling record book
  • regular inspections and proactive cleaning of the slime layer and macrofouling on all submerged surfaces and niche areas.

Best practices are outlined in the International Maritime Organization's (IMO's) Guidelines for the control and management of ships' biofouling to minimize the transfer of invasive aquatic species.

Download the IMO's biofouling guidelines

What to put in a biofouling management plan [PDF, 1009 KB]

If you do not know if your vessel has been managed using best practice, MPI has guidance to help you check your vessel's risk level.

Self-assess your vessel's risk profile [PDF, 195 KB]

Cleaning prior to arrival

For long-stay vessels, the recommended option is to clean the vessel's entire hull, including all niche areas, fewer than 30 days before arrival to New Zealand.

You must provide evidence that all hull and niche areas have been cleaned of all fouling in excess of goose barnacles and a slime layer. Acceptable evidence:

  • may include hull cleaning or dry docking reports
  • should include photographs or video of all hull and niche areas after cleaning.

Cleaning with an MPI-approved treatment supplier

If you know your vessel is fouled and you want to have it hauled out or re-fitted in New Zealand, before you arrive you must:

  • book an appointment for haul-out with an MPI-approved treatment supplier (the booking time must be within 24 hours of arrival)
  • give MPI evidence of your booking with the provider.

Currently, in-water cleaning of international vessels is not allowed in New Zealand. This means that there are no approved providers of in-water cleaning services for international vessels at this time.

Non-compliant vessels

If you cannot provide verifiable evidence that you've used one of the compliance options above, MPI may:

  • require a hull inspection on arrival to New Zealand
  • restrict your New Zealand itinerary
  • restrict entry of your vessel to New Zealand
  • ask you to clean your vessel within 24 hours by an approved provider in New Zealand.

These measures will be at the expense of the vessel owner or operator.

If you are directed to undertake a hull inspection on arrival, you can choose the inspection provider who will do this.

Specific advice for your vessel type

Check what you'll need to do to get your vessel ready to meet the new biofouling requirements.

Biofouling management for commercial vessels

Biofouling management for work vessels

Biofouling management for commercial fishing vessels

Biofouling management for recreational vessels

MPI can help you prepare

MPI can help you:

  • develop MPI-endorsed codes of practice for your industry group to help members comply with requirements
  • develop an MPI-approved craft risk management plan for your vessel
  • get advice on acceptable hull preparation, cleaning, treatment, and inspection.

For further details, email

Find out more

Technical guidance on biofouling management for vessels arriving to New Zealand [PDF, 402 KB]

Science behind the CRMS thresholds [PDF, 901 KB]

Who to contact

If you have questions about:

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