Northern Pacific sea-star (Asterias amurensis)

Body contents

Northern Pacific seastar (Asterias amurensis) is a large, aggressive predator of native species, including oysters, mussels and scallops. It can affect commercial fishing and aquaculture.

What to look for


  • yellow to orange with purple markings (juvenile)
  • yellow (adult)
  • 5 arms with pointed upturned tips
  • up to 50cm across.
Northern Pacific seastar

Where to look

Look in or around:

  • artificial structures
  • mud
  • rock pools
  • rocky reefs
  • sand.

Likely habitats include:

  • bays and estuaries
  • shores and shallow waters, up to 200m deep (usually shallower than 25m deep).

Established pest in Port Phillip Bay, Victoria and along the east coast of Tasmania.

Similar native species

These native species look similar to Northern Pacific seastar. They do not need to be reported.

Uniophora spp.


  • 5 arms
  • rounded tips, not pointed
  • up to 20cm across.


  • mud and sand in sheltered areas
  • rocky reefs
  • seagrass beds
  • up to 140m deep.

Known to occur from northwest Solitary Island, New South Wales to Great Australian Bight, South Australia, Bass Strait and Tasmania.

Coscinasterias muricata

Northern Pacific seastar


  • 7 to 14 arms (usually 11)
  • pointed tips, not upturned
  • up to 50cm across.


  • mud, sand and rocky reefs in sheltered areas
  • up to 140m deep.

Known to occur from Port Denison, Queensland to Houtman Abrolhos, Western Australia. Including the Great Australian Bight, Bass Strait, Tasmania, Norfolk Island and Lord Howe Island.


Report it

See something unusual? Report it. Even if you’re not sure.

If you see something you think is a pest:

  • note the exact location (screenshot your map app or enable photo geotagging on your phone)
  • take a photo (use something for size reference, like a coin or note)
  • contact your state or territory authority.


Stop the spread of marine pests

Start with these simple steps:

  • Inspect and clean your boat or yacht. Make sure you check hard to reach areas.
  • Treat the hull of your boat or yacht regularly.
  • Clean and dry your fishing and diving gear after every use.
  • Check aquaculture stock is free from pests.

How you can stop the spread of marine pests.

Your location

Check our marine pests map.

The map shows known pests and pests to look for around Australia.

Northern Pacific sea-star (Asterias amurensis)

Northern Pacific seastar (Asterias amurensis)

In Australia

Features: Yellow to orange with purple markings, grows to yellow as an adult. 5 arms with pointed, upturned tips.
Habitat: Up to 200m deep, bays, estuaries and reefs.
Affects: Native species, including oysters, mussels and scallops.
Movement: Vessels, fisheries and aquaculture stock.