Western Australia has an extensive and unique marine environment. There are productive marine ecosystems that underpin valuable and diverse fisheries, which can be marketed on a clean and green image. These ecosystems and fisheries are at considerable risk through the introduction of marine pest species which can cause significant ecological and economic losses to fisheries, marine industry and human health problems. Numerous species have already been introduced into WA, including pest species. It is essential that a Statewide program be initiated to determine the extent of the problem and develop strategies that can minimise the possibilities of further introductions. The present project will do this by assembling existing information available in numerous diffuse sources, developing new information, and trialling new strategies for minimising the introduction of more pest species. The project will be integrated with existing programs on both a State and national level.