Marine pests
Mediterranean fanworm
Chris Woods/NIWA
Marine pests pose a major threat to Canterbury's beautiful coastal waters. It's important that we all work together to limit their spread.
Marine pests are species that have been introduced to our waters and have the potential to severely damage our marine ecosystems by outcompeting native species for food and space. This damage can have a devasting effect on our natural resources, marine industries, water quality and mahinga kai.
Marine pests often enter our region and spread via boat hulls. Find out what these pests look like, how to report them, and how to help stop their spread.
Marine pests to be on the lookout for
Alternatively, you can take a photo and upload it to the Find-A-Pest app. If taking a photo of a vessel, be sure to capture the name and its location for tracing purposes.
Alternatively, you can take a photo and upload it to the Find-A-Pest app. If taking a photo of a vessel, be sure to capture the name and its location for tracing purposes.
While their impact can vary between locations, they can form dense underwater ‘forests’ that lead to the exclusion and displacement of native plants and animals. They can also be a problem for the aquaculture industry by increasing labour and harvesting costs.
Alternatively, you can take a photo and upload it to the Find-A-Pest app. If taking a photo of a vessel, be sure to capture the name and its location for tracing purposes.
Be a good boatie and make sure pests don't catch a ride with you!
You can help protect Canterbury's beautiful waterways and marine ecosystems by being a good boatie and keeping a clean hull. Limiting the fouling on your hull stops pests from catching a ride with you into uncontaminated areas or transferring from your vessel to others when moored or berthed in a marina. Keeping your vessel in good shape will also improve its fuel economy and speed.
When cleaning your hull, do it right. Taking shortcuts can make the problem much worse. You must ensure that no contaminants, like marine pests, are discharged into the water during your cleaning process.
- Haul out and remove larger fouling organisms by hand. Don’t throw these back into the water where they can easily reproduce! Instead, dispose of them in a secure bin.
- Water blast or brush off smaller material at a facility where all wash off is contained and treated. Do this at least annually or when fouling builds up beyond a light slime layer. Pay attention to appendages that protrude or retain water such as the keel, intakes/outlets, propellers and shafts.
- Antifouling paints are useful for preventing a build-up of unwanted organisms and pests on your hull. However, they contain ingredients that can harm marine life. Always follow the manufacturer's instructions when applying antifouling paint and collect and dispose of any waste appropriately.
- Regularly treat internal seawater systems and flush with freshwater or an approved treatment.
- Other equipment such as trailers, anchors, dive and fishing gear should be washed with freshwater after use, and then allowed to thoroughly air dry before using in a new location
- Always check your boat is clean before you move location.
Useful resources
- Learn more about how to Check, Clean, Dry your vessel and equipment.
- The marinepests.nz website also offers tips for keeping boats clean and well maintained.
Antifouling paint cover is the easiest way to keep your vessel clean. However, the ingredients in the paint, such as cooper, can harm marine life. Always apply and remove antifouling paint with careful consideration.
- Antifouling paint generally lasts between one and two years, but always renew the paint at the interval recommended by the manufacturer. Clean and renew any paint that has been scraped or damaged, and always dispose of waste appropriately.
- Antifouling paint works best with more than one coat applied to a clean, dry hull. Allow each coat to dry between applications and allow final coat to cure for 24 hours before re-launching.
For more information download the Environment Protection Authority's PDF guide to safely using antifouling paints.
Seen something unusual? Report it
Call the Ministry for Primary Industries' Pest and Diseases hotline on 0800 80 99 66. If possible, please take photos and record the location. The location could be the name of a vessel and where it was moored, or the physical location if it was found on the sea floor or structures.
The Find-A-Pest app enables you to report potential pest species, including marine, plant, animal and fungal species.
If you come across something out of the ordinary, simply upload a picture to the app and a Find-A-Pest specialist or the iNaturalist community will help identify it. If your observation is considered a potential biosecurity threat, this will be forwarded to Biosecurity New Zealand to contact you if necessary.
If taking a photo of a vessel, be sure to capture the name and its location for tracing purposes.
Resources
Check out the following resources to learn more about marine biosecurity in New Zealand:
