BIA Victoria - Northern Pacific Seastar

Northern Pacific Seastar

The northern Pacific seastar is a voracious predator native to Japan, Russia and Korea. It is considered a serious threat to our native marine ecosystems, native shellfish and shellfish industries.

The first record of the seastar in Australia was in the 80’s in Tasmania. It was most likely carried there by a ship from Japan.

• In 1995, two seastars were found in Port Phillip Bay, probably carried from Tasmania by ship. 

• Then in 1998, over 100 juvenile seastars were found off Dromana.

• By 1999, it was estimated that the seastar covered 100 kms2 of the Bay.

• In the year 2000, it was estimated that there were 165 million seastars in the Bay.
  
  

The seastar took hold in the Bay very quickly because:

• they had no natural predators

• they had plenty of food (native shellfish)

• and they reproduced extremely rapidly, with each female producing up to 20 million eggs each year.

The northern Pacific seastar competes with native fish and seastars for food, and impacts on the Bay’s shellfish farms. In Tasmania, the seastar has been blamed for the serious decline in handfish populations, and in Port Philip it has been implicated in the decline of flathead numbers.

As far as we know, the seastar is not established anywhere in Victoria outside Port Phillip Bay. To make sure the seastar does not invade other waters, you need to make sure your boat and gear is clean before you move from the Bay to other locations.

It is important to check for large adult seastars but you also need to make sure you are not carrying eggs or baby seastars. To do this you need to drain out all water, rinse your boat and gear with fresh water and dry everything completely. This will kill eggs, juveniles and adults.

Here are some simple guidelines to make sure your boat is not carrying the seastar or its eggs:

Click here if you moor your boat (yachts, cruisers etc)

Click here for trailer boats, canoes, kayaks and jetskis 

What does the northern Pacific seastar look like? The invasive seastar has 5 arms and is usually orange and purple. The arms are pointed at the ends and the tips are often curled upwards.

 

 

 DO NOT remove these native seastars from the Bay by mistake. 

            

The native 5 armed seastar can be orange as well, but it has rounded tips that are not curled upwards. We also have a native 11 arm seastar. It is often green-grey and has between 7 and 11 arms.

If you find a northern Pacific seastar in Port Phillip Bay, take it back to shore and throw it in the bin. DO NOT cut it up and throw it back into the water – they can grow an entire body from a single arm.

If you think you have seen the invasive seastar outside of Port Phillip Bay you should report it to the Department of Sustainability and Environment by calling 136 186.

How do we get rid of the seastars?
Removing the seastars from the Bay by hand or machine is not really an option. The cost of such an operation would be huge, and unless every seastar is found they could easily re-establish.

Scientists are now looking into other ways to get rid of the seastar like introducing a disease, parasite or genetic mutation that would destroy the population. Research like this is expensive and takes a long time. Until we have this “cure” we need to make sure the seastar is not spread into other waters by checking and cleaning all boats and gear after every use.

For more information on the northern Pacific seastar follow these links:

National Introduced Marine Pest Information System (CSIRO)

Northern Pacific seastar in Port Phillip Bay (Department of Sustainability and Environment)