Marine pests in Tāwharanui Marine Reserve

Introduction

What is the impact of marine pests on the ecosystem at Tāwharanui Marine Reserve and how is it changing?

Status: good

Marine pests are species that have been introduced to New Zealand waters by human activities and have the potential to cause significant impacts to the country’s marine environments and resources.

The diversity and abundance of marine pests in Tāwharanui Marine Reserve is currently low.

Trend: stable

Auckland Harbour contains several pest species that could be introduced by passing boats and ships. Two pests that are targeted for prevention, containment or control by DOC are present within 50 km of the reserve. There is a high chance they will arrive in the marine reserve in the future.

  • Undaria pinnatifida: a Japanese kelp that competes with native seaweeds. Undaria is already established in many parts of New Zealand, including Great Barrier Island (mostly near mussel farms and other structures) 60 km away.
  • Styela clava: a stalked sea squirt that forms dense colonies and smothers other species. It is established in many parts of New Zealand and the closest recorded colony is less than 5 km from the reserve.  

Sabella spallanzanii, the Mediterranean fanworm, is an unwanted organism and is established in Waitemata, Whangarei and Coromandel harbours, approximately 100 km away. 

Monitoring

There is no monitoring for marine pests in this marine reserve. The Ministry for Primary Industries (MPI) maintains a national database of marine pests. MPI has also published a marine pest identification guide (PDF, 1,710K).

Call MPI on 0800 809 966 and notify DOC via marine@doc.govt.nz if you find any marine pests in the marine reserve.

Reports

The Auckland Conservation Management strategy highlights the marine pests that pose a threat to marine ecosystems within the Hauraki Gulf. See Volume 1, Appendix 5, Table A5.3.