Exotic marine species have the potential to become serious pests to the detriment of Australian marine ecological communities and important industries such as tourism and fishing. Management of ship ballast water and biofouling is the key control to prevent the spread of these species.

All international vessels arriving at Fremantle are required to manage their ballast water in accordance with the Australian Ballast Water Management Requirements.

The Federal and State governments are implementing Australia's National System for the Prevention and Management of Marine Pest Incursions. This system aims to prevent new marine pests arriving, guide responses when a new pest does arrive and minimise the spread and impact of pests already established in Australia.

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Asian Green Mussel infestation

In Western Australia, Fisheries (Department of Primary Industries and Regional Development) is the responsible agency for marine biosecurity including the control and prevention of introduced marine species through biofouling.

Fremantle Ports requires vessels within port limits to manage biofouling in accordance with the National Biofouling Management Guidelines. Guidelines for commercial, fishing and recreational vessels are available at the Australian Government’s Marine Pests website. 

Fremantle Ports runs a voluntary marine pest surveillance program in cooperation with Fisheries (Department of Primary Industries and Regional Development). This monitoring program consists of settlement array deployment, shoreline searches and crab traps and condos.

Settlement arrays are used as an early warning system for the detection of introduced marine pests as well as a record of other marine organisms in the surveys area. The arrays are simple structures that provide extra surfaces for organisms to settle on that are then collected and examined by marine pest experts.

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Settlement array

Shoreline searches are conducted quarterly at low tides. Running parallel to the waterline, the searches include both intertidal and beach locations. As well as examining rocks and artificial structures, searchers also examine wrack in detail as dead material present in wrack could provide an indication that a pest species is or was present in the area.

Crab traps are used to target six pest crab species that have the potential to survive in the Fremantle Port area. More recently, artificial habitat collectors known as ‘crab condos’ have been added to the program to specifically target smaller crab species.

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Crab condo (WA Department of Fisheries photo)

Suggested references:

The National System for the Prevention and Management of Marine Pest Incursions (Federal Government initiative)

Federal Department of Agriculture and Water Resources (Biosecurity)  

Fisheries (Department of Primary Industries and Regional Development) - Aquatic biosecurity