Cetec with the assistance of 3AK radio initiated and coordinated the Marine Pest Days (Port Phillip Bay) in 2000 and 2001.  This involved more than 700 divers, fishermen, boat owners and the coastal community in assessing the seastar population to have been approximately 150 million in number at that time. 

Northern Pacific seastars (Asterias amurensis) are a large yellow and purple coloured starfish. They are believed to have been introduced into Tasmania from Japan in the 1980s (from Ballast water), although they were not identified from the area until 1992. Since that time the seastar has also established large populations in Port Phillip Bay and has just recently been found in South Gippsland (Victoria) in small numbers.  In both Tasmania (Derwent River) and Victoria the numbers are now in the millions with an estimated 165 million in Port Phillip Bay alone.  Northern Pacific seastars are native to the coasts of China, Korea, Russia and Japan.

The Department of Sustainability and Environment (VIC) on 22nd January offically confirmed the South Gippsland infestation after a three-day dive  during that week.  Divers found 18 seastars at Point Norman, near Inverloch, following local residents reporting their presence just prior to Christmas.

Why the concern?

Australia's National Control Plan for the northern Pacific seastar says there is "abundant evidence" that the pest threatens marine biodiversity and the economic competitiveness of marine industries - such as aquaculture, the scallop industry and wild fisheries. They are voracious predators and eat a wide range of native animals. There is evidence that the seastar has contributed to a 40% drop in fish stocks in Port Phillip Bay.

The seastars found at Inverloch were all about one year old and are not due to spawn until April or May, however each female will produce 19 million eggs.  Time is therefore limited to act upon this known outbreak.  The Department of Sustainability and Environment are looking for volunteer recreational divers to help find and get rid of the Northern Pacific Seastar near Inverloch.  You can email seastar.2004@dse.vic.gov.au to register for the dive.

While no known populations currently exist in NSW, SA and WA (probable suitable habitats), their high rate of reproduction, tolerance of a wide range of environmental conditions and high potential for dispersal via natural means and via the shipping industry, suggest that the species could also spread into these states.