Over summer, NIWA marine scientists surveyed high-risk locations within the Waitematā Harbour for exotic pests on behalf of Biosecurity New Zealand. The goal is to detect exotic pests as soon as they arrive in Aotearoa New Zealand waters to increase the chances of successfully managing them. This is part of Biosecurity New Zealand’s national marine surveillance programme which has been undertaken since 2002.
Five hundred and four locations were sampled within Waitematā Harbour, using a variety of search methods. These methods sample habitats such as, sea floors, pontoons, piles, vessel berths and rocky shores. The great news is that no new-to-New Zealand marine species were detected in any of these samples.
Divers did detect the exotic lightbulb ascidian Clavelina lepadiformis (see picture below) at the Viaduct Harbour for the first time. This species has been previously been detected in Whangārei, Whangaparoa, Tauranga, Wellington, Picton, Nelson, Lyttelton and Dunedin. This species is in Auckland Council’s Pest Management Plan and earlier in the year this species was detected on a vessel hull in Bayswater Marina. Follow up enforcement action was taken to ensure the vessel was cleaned in a bio-secure manner to prevent further spread.
Exotic Caulerpa seaweeds recently found at Great Barrier (Aotea) and Great Mercury (Ahuahu) islands, were not detected in Waitematā Harbour during this survey.
It takes all of us to prevent the spread of exotic pests throughout New Zealand and ensuring any equipment is clean and dry and your vessel has a clean hull free of biofouling before moving to a new location will ensure the protection of the places and activities we value for present and future generations.
The next Waitematā Harbour survey will occur in August. If you want to see the current distribution of marine pest species in New Zealand waters click here.