Biofouling management

Marine pests and diseases brought in on vessel hulls (biofouling) are a threat to New Zealand's marine resources. From May 2018, all vessels arriving in New Zealand will need to have a clean hull. Find out about the new biofouling requirements, and how MPI can help you work towards compliance.

New rules to protect our marine environment

Marine pests and diseases brought in on vessel hulls (biofouling) can cause significant harm to New Zealand's marine biodiversity and its fishing and aquaculture industries. To manage this risk, MPI has brought in new requirements for biofouling on vessels arriving in New Zealand. These rules require all vessels to arrive in New Zealand with a 'clean hull'. Complying with the rules is voluntary until May 2018. Until then, MPI continues to take action on vessels that pose a severe biofouling risk.

Requirements are set out in the Craft risk management standard (CRMS) for biofouling on vessels arriving to New Zealand.

Download the craft risk management standard for biofouling [PDF, 241 KB]

View a diagram explaining severe biofouling risk [PDF, 1 MB]

MPI is also developing a CRMS for the whole vessel, which will eventually include the CRMS for biofouling.

Clean hull requirements come into force in 2018

From May 2018, vessels must arrive in New Zealand with a clean hull. Vessels staying up to 20 days and only visiting designated ports (places of first arrival) will be allowed a slight amount of biofouling. Vessels staying longer and visiting other places will only be allowed a slime layer and goose barnacles.

Descriptions and images of allowable amounts of biofouling are in the guidance document for the CRMS.

Download the draft guidance document for the CRMS on biofouling [PDF, 1 MB]

Aligning New Zealand's rules with international guidelines

New Zealand's CRMS requirements are based on the International Maritime Organisation's Guidelines for the control and management of ships' biofouling to minimize the transfer of invasive aquatic species. These provide examples of biofouling management best practice.

Download the IMO's biofouling guidelines

Vessels complying with these guidelines will also be compliant with the CRMS.

Complying with new biofouling requirements

You will be able to meet the new clean hull requirements by doing one of the following:

  • cleaning the vessel hull before arrival in New Zealand (less than 30 days before arrival)
  • doing continual maintenance on the hull (see below)
  • treating organisms on the hull (for example, with heat or chemicals) to kill them or make them sterile.

You can also submit an alternative approach to preventing unwanted marine pests (a craft risk management plan) to MPI for approval. For advice on developing a craft risk management plan, email

What is continual maintenance?

Continual maintenance involves ongoing management of biofouling, including:

  • having a biofouling management plan specific to the vessel
  • coating the hull with antifouling paint to prevent or minimise biofouling
  • regularly inspecting and cleaning the hull
  • keeping records to show how biofouling is managed.

Biofouling management plan and record book templates are in the guidance document for the CRMS.

Moving to the new standard

During the lead-in period to the CRMS, MPI is encouraging vessel owners to comply voluntarily with the new requirements.

What to do before arrival

All vessel operators arriving in New Zealand must now complete a biofouling declaration (part 1 of the Biofouling and ballast water declaration). This is usually sent prior to arrival with the Advance notice of arrival (Customs' form). The advance notice of arrival form you use will depend on your vessel type.

When you arrive

On arrival, you may also be asked to show your biofouling management plan and/or records to the quarantine officer. MPI uses these to:

  • assess your vessel's biofouling management
  • assess your vessel's biofouling risk
  • monitor your progress towards compliance with the CRMS.

As always, MPI will take action on vessels that arrive with heavy biofouling. If your vessel hull has to be inspected or cleaned, this will be at the vessel operator's expense.

Lead-in time gives industry time to prepare

The lead-in period to the CRMS allows time for:

  • vessels to become compliant
  • better antifouling technology to be developed
  • more hull-cleaning services to become available.

Specific advice for your vessel type

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

Heavily fouled work vessels

Slow-moving or stationary work vessels, such as project vessels, drill rigs, tugs and barges, can become heavily fouled. Heavily fouled vessels must be cleaned or treated before arriving in New Zealand.

  • To check if the biofouling on your vessel hull is acceptable, email
  • To discuss acceptable hull preparation or to provide evidence of cleaning or treatment, email

Yachts and other recreational vessels

Arriving yachts and other recreational vessels need to meet the biofouling requirements as part of getting clearance to cruise freely in New Zealand.

Commercial cargo and cruise vessels

Most commercial cargo and cruise vessels will use continual maintenance to manage biofouling. On arrival, MPI may ask to see your biofouling management records, including dates of dry docking, antifouling maintenance, inspections and cleaning.

Biofouling requirements for commercial shipping [PDF, 491 KB]

Vessels arriving for refit or haul-out

If a vessel is fouled but you plan to have it refitted or hauled-out, then to be compliant with the CRMS it must be cleaned in an approved facility or cleaned (with capture of removed material) by an approved dive cleaning provider immediately on arrival.

Approved treatments and providers

If using the clean or treat option under the CRMS, you will need to provide MPI with evidence of the hull cleaning or treatment, preferably by an MPI-approved system or provider. This can be provided ahead of the visit or when your vessel is arriving in New Zealand.

MPI is developing the details for approved cleaning and treatment systems, as well as the process for getting MPI approval. These will be made available on the Registers and lists page of our website.

To discuss becoming approved, email

MPI can help prepare for the biofouling CRMS

MPI can help you:

  • develop MPI-endorsed codes of practice for your industry group to help members comply with the new requirements
  • develop a craft risk management plan for your vessel. This will need to be approved by MPI.

For advice on developing a craft risk management plan, email

Get the latest news on the biofouling CRMS

MPI releases regular updates and alerts to keep you up-to-date with the new biofouling requirements.

Updates on the CRMS

Biofouling readiness alerts

MPI has released the following biofouling readiness alerts:

To subscribe to biofouling readiness alerts, email

Other resources

Who to contact

If you have questions about:


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