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In the water - marine pests

Mediterranean fanwormVessels from all over the world enter Tauranga Harbour every week bringing in imports such as oil and fertiliser, and taking out exports such as kiwifruit and logs. Recreational sailors and fishermen also regularly bring their boats here from other parts of the country.

Unfortunately these vessels can bring marine pests with them. The pests hitch a ride as fouling on ships' hulls, or in ballast water discharged into our coastal waters.

Several unwanted marine pests such as Mediterranean fanworm (pictured right) have been found in Tauranga Harbour, we need your help to keep them out. See our marine pests page for more information.

On the land - pest plants and animals

Find out about specific pests and how to control them at

Many unwanted plants and animals live in or around the land surrounding the Tauranga Harbour. Pest animals around the harbour that eat native plants and birdlife or eat food that native animals need include:

  • possums
  • rats
  • mustelids (ferrets, stoats and weasels),
  • cats
  • mice
  • Argentine ants

Tauranga Harbour hosts a substantial population of resident black swans (Cygnus atraus) which are becoming pests and destabilising sea grass (Zostera) which they appear to graze. In 1994, Environment Bay of Plenty estimated that black swans had removed 25-35% of seagrass at the southern end of the Otumoetai foreshore.  Seagrass beds are important in increasing species diversity and abundance, and the biomass of benthic (bottom-feeding) communities.

Spartina (cord grass)Pest plant species in and around the Tauranga Harbour include: Spartina (pictured ledt), salt-water paspalum, morning glory, ice plant, gorse, pampas, woolly nightshade and wild ginger. 

These weeds can smother and replace native plants or increase coastal sedimentation around the harbour. 




What are we doing?

We have pest animal and plant control and surveillance programmes in place.

Bay of Plenty Regional Council works with the Department of Conservation and other land owners to ensure that pests such as spartina are controlled.

We also work with MPI Biosecurity New Zealand and research providers such as University of Waikato and Bay of Plenty Polytechnic to monitor the presence and effects of marine pests, and to promote marine biosecurity awareness in the region.

What can you do?

Keep a look out for unwanted pests in and around Tauranga Harbour.  Report any suspicious finds to us by calling 0800 884 880 or to the Ministry for Primary Industries exotic pests and diseases hotline, phone  0800 80 99 66

Boat owners - regularly clean and anti-foul your vessel's hull to minimise the chance of transporting pests, including those featured in this fact sheet, around the coast and  particularly to high value marine areas such as Tuhua - Mayor Island.  Clean boats are unlikely to spread marine pests.

Land owners and occupiers - check out your pest control responsibilities and ask us for help. We can advice on the best control methods and may be able to supply herbicide, pesticide or traps.

Need more information?

Visit our pest management pages or read the Tauranga Harbour biosecurity factsheet to find out more.

For more information on unwanted species in New Zealand check out the pest watchlist on the Biosecurity New Zealand website

Other useful websites include: