Antifouling and cleaning are vital in protecting the environment

Antifouling & cleaning vital in protecting environment, too!

While owners of moored boats generally understand the benefits of maintaining an effective antifouling system, they may not be aware of the vital role it plays in protecting our environment.

According to MAF Biosecurity New Zealand (MAFBNZ), our waters and coastal environments are coming under increasing threat from “foreign” marine organisms, two-thirds of which have arrived on the hulls of visiting vessels  from large merchant ships to small cruising yachts.

One example is the Australian sea squirt, Eudistoma elongatum. Over the past few summers, this unsightly white sausage-like organism has been steadily infecting Northland bays and Dirty propeller not anitfouledharbours. It probably arrived in New Zealand on the hull of an ocean-going vessel and is now so prevalent in the area that it is too widespread to tackle effectively.  

The fouling sea squirt Styela clava (different but just as nasty as its Australian cousin) is now widespread throughout the Hauraki Gulf and has also been found in Lyttelton and in two marinas in Northland.

It, too, was almost certainly spread on boats, possibly pleasure boats with hulls that had not been properly antifouled.

In Lyttelton, MAFBNZ is currently looking at how they can treat a new invader, a species of fanworm called Sabella spallanzannii, discovered during routine surveillance of the area.Front view of heavy fouling

Unfortunately, once they arrive in new waters, marine organisms such as these sea squirts (and worms, sea stars, crabs, clams and various weeds) have the ability to really prosper. This can, not surprisingly, cause irreversible damage to their new environment.

Some of these unwanted pests can literally overrun native ecosystems, adversely affect fish stocks, negatively impact on marine farming and tourism and be incredibly unsightly.  

Sadly, once established here, these marine pests are extremely difficult to control or eliminate. All any of us can realistically do is prevent them (and all other fouling pests) from hitchhiking to other areas on our hulls. This is especially important for high value areas such as marine reserves and areas that are currently not infected with these pests.Regular cleaning of the hull is important

The best way of doing this is simply by ensuring that hulls are clean and protected with an effective antifouling coating. Therefore, as part of their strategy to minimise the spread of these harmful organisms, MAFBNZ has launched a new campaign aimed at encouraging boat owners to regularly clean and properly antifoul their hulls.

As part of the campaign, all cans of antifouling from New Zealand’s specialist marine paint manufacturer, Altex Coatings, are now being sold with a new “Clean Boats – Living Seas” sticker on the can. On the sticker is the address of a new webpage ( that features detailed hull cleaning information. That page also links to MAFBNZ’s website ( where there is a comprehensive array of information on marine pests, as well as advice on cleaning and antifouling. There are also illustrative guides and a newly-produced instructional DVD.

Information brochures promoting the Clean Boats – Living Seas message will also be prominently displayed in chandleries and marine supply stores around the country.

MAFBNZ’s Lesley Patston says the role boaties can play in protecting the environment cannot be over-estimated.

“It’s everyone’s responsibility to protect what they value. If boat owners follow some simple biosecurity precautions they will help keep the seas alive for future generations,” she says.

Patston urges owners to regularly clean their boat’s bottom: “Do not allow any build up of growth beyond a slime layer.” Particular attention should be paid to what are known as “niche” areas: parts of the boat that stick out or retain water. These are areas such as the keel, intakes and outlets, propellers and shafts, rudders and casings. They are prime areas for harbouring pests.

Patston also urges owners to put any debris removed from the hull into rubbish bins on land, so as to prevent it getting back into the water.

“Ensure your antifouling is in good condition and re-applied as recommended by the manufacturer or retailer. Renew if it’s been scraped or damaged or if persistent fouling is occurring.

“Finally and most importantly: check your boat is clean before you move location. If it’s not, clean it!”

MAFBNZ is also working to stop marine pests arriving here in the first place. The Government has just agreed to sign an international agreement on ballast water. Once in force, this will see ships required to treat ballast water onboard before it is discharged.

As well, New Zealand is leading work through the International Maritime Organisation, pushing for the development of consistent, internationally agreed biofouling management measures for all vessels.  

MAFBNZ is also developing new standards requiring all arriving vessels to demonstrate their cleaning history and that they have a clean hull.

The biosecurity agency is also urging boaties to keep an eye out for new pests:

“Because boaties are out and about on and around the sea, they are well placed to notice things that may seem unusual.  If anyone comes across a marine plant or sea life that looks out of the ordinary, it would be great if they could note its location (as accurately as possible), collect a sample (if they can) and phone MAFBNZ on our freephone: 0800 80 99 66.

“The sooner MAFBNZ hears about potential marine pests, the better chance we have of successfully controlling or eradicating them.”

For more information, please contact:
Lesley Patston
MAF Biosecurity New Zealand
Telephone: (04) 894-0163
Mobile: (029) 894-0163