Maximum latitudinal extent of selected key non-indigenous species

Marine non-indigenous (exotic) species arrive in New Zealand waters on the hulls of international vessels (biofouling) or in discharged ballast waters. Some have little impact or cannot survive in New Zealand waters; others have a negative impact on our native habitats and species and become pests. They can compete with, and prey on, indigenous species, modify natural habitats, affect marine industries or can alter ecosystem processes. The potential impact of non-indigenous species on our native habitats and species means they could threaten our cultural and natural heritage, as well as economic activities such as commercial and recreational fishing, shellfish harvesting, and aquaculture.
The maximum latitudinal extent is the range between the northern-most and southern-most records of these species.