Introduced Marine Aquatic Invaders - a field guide

How pests get here

The Northern Pacific seastar (Asterias amurensis) was introduced to Tasmania from Japan in the 1980s, but initially was confused with a native species. By the time it was recognised as a marine invader in 1992, there were millions of seastars lining the seabed. Being a large, highly mobile predator that has few native enemies and a ferocious appetite, the Northern Pacific seastar is recognised as a significant pest, with the potential to have a considerable impact on the marine environment, commercial and recreational fisheries and the aquaculture industry. Currently there is no record of this species in WA, and hopefully there never will be.

Photo CSIRO Marine Research

There are a variety of ways in which marine species are transported to Australia. Some of these are more successful than others.

Ever since ships started to navigate the seas and oceans of the world carrying passengers, cargo and crew, they have also inadvertently transported marine species. Some marine species attach themselves to vessel hulls and other associated structures (such as water inlets), or may be transported in ballast water.

Aquaculture activities in some countries and Australian states have resulted in the deliberate introduction of non-native aquatic plants and animals so that they can be cultured for food. When an aquaculture species is being transported from one place to another, other animals and plants may be introduced unintentionally in the transport water or packaging, or may attach themselves to the aquaculture species.

Commercial shipments of seafood also provide a transport opportunity for marine species, which can hitch a free ride by means of the seafood itself, its packaging or the transport water.