The New Zealand screw shell has a hard, smooth conical shell up to 9cm in length. It is a native New Zealand species that can survive in a range of different habitats, and has established successful populations in New South Wales, Victoria and Tasmania.
It forms a dense covering on the sea floor with live and dead shells at depths up to 100m, and competes with native shellfish for food.
New Zealand Screw Shell
Similar native species
Mud whelk / Velacumantus australis
Native screw shell / Gazameda gunnii
Hercules club whelk / Pyrazus ebeninus
On the 1st July the NSW Government implemented the new Biosecurity Act 2015 (the Act). Under this new legislation the New Zealand Screwshell are declared as a notifiable species in NSW under Part 2, Schedule 1 of the Biosecurity Regulation 2017 (the Regulation). Under Part 2, Division 5, Clause 18 of the Regulation it is illegal to possess, buy, sell or move this pest in NSW. Heavy penalties apply for non-compliance.
People are expected to have a basic level of knowledge about the biosecurity risks they might encounter in their normal work and recreational activities. All community members have a general biosecurity duty to consider how actions, or in some cases lack of action could have a negative impact on another person, business enterprise, animal or the environment. We must then take all reasonable and practical measures to prevent or minimise the potential impact.
Learn to recognise, and be aware of, the New Zealand screwshell so that you can report any suspected new sighting.
If you see this pest in NSW, please report it immediately