Local Ranger Steve Tuohy says it is very disappointing to find the seastar in this valuable marine environment.

"The waters and wetlands of this small bay are internationally significant, especially its seagrass meadows which are essential feeding areas for migratory wader birds. It also plays an important role as a fish nursery. The bay will now be monitored for any further signs of this marine menace.

"Marine pests like these can have catastrophic impacts. They destroy habitat, compete with the native species and even eat them. They have been a key factor in extinctions around the world for the last few hundred years, and it goes without saying that they are a serious threat to our Marine National Parks," he said.

The Northern Pacific Seastar is a voracious predator that feeds on a wide range of native animals and shellfish. It may be yellow, orange or purple, has five arms with sharp tips which are often pointed upwards, and is similar to a native species which has more rounded tips. It is already widespread around Port Phillip Bay.

Marine pests are spread into new areas in a number of ways; via the transfer of equipment or materials from one area to another, through activities like marine farming and fishing, and by ballast water and dirty hulls on boats. This is particularly serious when boats travel from Port Phillip Bay into other locations where these pests currently don't occur. Once they become established, marine pests are very difficult to eradicate.

Parks Victoria is calling on all boat operators to help prevent the spread of the sea stars and other invasive pests into new areas by practicing the 'Six D's:
Dislodge any attached plants or animals after boating.
Drain all sea water from the vessel including any in wells.
Douse boats in freshwater wherever possible.
Dry the boat thoroughly.
Dispose of unwanted live bait.
Don't forget to use authorised antifoulant.

Marine Science Manager for Parks Victoria, Dr. Steffan Howe, says further investigation of the pests in Swan Bay is planned for early next year. "This will include a research project with the University of Melbourne on predicting the potential spread of marine invasive species into our Marine National Parks and Sanctuaries. The project will look at ways of improving surveillance and detection of these species, which will help current management of this serious threat to our marine biodiversity," he said. Surveillance for marine invasive species is part of Parks Victoria's ongoing monitoring program across many of the Marine National Parks and Sanctuaries. Brochures outlining how to implement the 'Six D's and prevent the spread of marine pests can be found in Parks Victoria's offices.

For more information on marine pests visit www.dse.vic.gov.au/marine or the Victorian Boating Industry Association at www.biavic.com.au/marine-pests