Soft-shell clam (Mya japonica)

​​The Department of Primary Industries, Parks, Water and Environment (DPIPWE) detected the introduced soft-shell clam in the the Prosser River at Orford, and within the northern aspect of Spring Bay during 2018. 

The clam is a large bivalve marine mollusc and genetic sequencing has confirmed it is Mya japonica. Soft-shell clams are native to the Northern Hemisphere, and this is the first detection of soft-shell clam in the Southern Hemisphere. The response to this detection is being managed in accordance with the National System for the Prevention and Management of Marine Pest Incursions with nationally agreed protocols.

Soft-shell clams can grow up to 150 mm and typically live in sand, mud and gravel in shallow sub-tidal and intertidal zones. The clam exists beneath the soil surface burying itself up to 50 cm deep. It uses long siphons, which pump water for respiration, feeding and spawning.
Considered an invasive species for their potential to outcompete native species for habitat, Mya japonica represents a potential marine pest risk to other areas of Tasmania and Australia through the spread of larvae on water currents, or within ballast water. Clams can also be spread by people moving adults to new areas where they may spawn.

It is very important that the clams are not collected or moved to other locations.

Taking and possessing of soft-shell clams prohibited

Following the recent detection of soft-shell clam, and in accordance with Section 270 of the Living Marine Resources Management Act 1995, Fisheries (Biosecurity) Order 2018 No. 2 was gazetted on Wednesday, 11 July 2018.

The Order formally prohibits the taking and possession of soft-shell clams in Tasmania by unauthorised persons. The Order has been issued to control and prevent the spread and introduction, or re-introduction of soft-shell clams (Mya japonica) into areas of State waters. 

The Order can be viewed on page 465 of the Tasmanian Government Gazette, published on 11 July 2018.

Anyone finding what they suspect to be a soft-shell clam are encouraged to contact DPIPWE on telephone at 6165 3777 or email:​  Supplying a photograph of the suspected soft-shell clam will assist in identification.

Mya japonica - soft-shell clam - top view
copyright: TMAG

Mya japonica - soft-shell clam - base view
copyright: TMAG

Mya japonica - soft-shell clam - close ups
copyright: TMAG

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