The Blue swimmer crab (Portunus armatus) is found along the entire coast of Western Australian, in a wide range of habitats from inshore estuaries and rivers to waters up to 50m deep on the continental shelf.
However, most commercially and recreationally-fished stocks are concentrated in the coastal embayments and estuaries between Geographe Bay in the south west and Port Hedland in the north.
Blue swimmer crabs are targeted using a variety of fishing gear but most commercial crab fishers in WA now use purpose-designed crab traps. Operators in the Pilbara Developmental Crab Fishery are only permitted to use ‘hourglass’ traps. The Onslow and Nickol Bay prawn trawl fisheries also retain crabs as a by-product.
The Pilbara Developmental Crab Fishery was established in 2001 under the exemption process. The exemptions were issued to allow for the sustainable exploration of the commercial viability of fishing crab stocks along the Pilbara coastline.
Two of the four species of mud crab (Scyllaspp.) found in the Indo-West Pacific region are found in Western Australia – the green mud crab (Scylla serrata) and brown mud crab (Scylla olivacea).
The green mud crab is mainly found in estuarine habitats in north-western Australia from the Northern Territory border to Shark Bay, although they have also been found as far south as the Wilson Inlet at Denmark.
The brown mud crab has a more restricted distribution, with most catches from King Sound 200km northwest of Broome.
Brown mud crabs are more tolerant of low salinity than green mud crabs, but less tolerant of lower temperatures.
The Kimberley Developing Mud Crab fishery is currently a small developing fishery that targets the green (giant) mud crab and the brown (orange) mud crab via the use of crab traps, between Broome and Cambridge Gulf near the WA and Northern Territory border.
Most fishing effort is concentrated around Cambridge Gulf, Admiralty Gulf, York Sound and King Sound.
From 2006, access to the Kimberley Developing Mud Crab Fishery has been granted via Exemptions, which were formerly issued under Section 7(3)(c) of the Fish Resources Management Act 1994, for ‘the exploration or development of fisheries or the development of fishing technology’.
Access to the Kimberley Developing Mud Crab Fishery is made up of two broad groups: Aboriginal Community Commercial Mud Crab Exemption holders and Commercial Exemption holders.
There are currently 3 commercial operators and 2 Aboriginal corporations holding exemptions to fish for mud crabs in WA. The fishers generally operate from March to November, with May to September being the most productive months, to avoid summer and associated seasonal cyclone weather events.
Commercial operators generally fish on a part-time basis with most operating other endorsements including Kimberley Gillnet and Barramundi Managed Fishery Licences and fishing boat charters. Operators tend to fish remote waters for long periods of time in large mother ships, using small dinghies known as dorys to enter mangrove estuaries with crab traps generally checked each daylight high tide.
Blue Swimmer Crab
During 2012-13, two people were employed as skippers and crew on vessels fishing for blue swimmer crabs along the Pilbara coast. Additional employment for several workers has been created in Point Samson through the development of post-harvest processing of the crab catch.
Historically the mud crab fishery has had a high community value and a low commercial value. Commercial fishers travel vast distances due to the remoteness of their operations and stay in the vicinity for several weeks before returning to unload catch. In this scenario crabs are frozen and generally sold to local markets although live product may also be sold at premium prices.
Due to an absence of adverse weather including seasonal flooding and cyclone activity reported in previous years, there was a higher than normal fishing level with 3 commercial operators and 2 Aboriginal Corporations in the 2013 fishing season.
Key Species Fished
|Blue Swimmer Crabs|
|Brown and Green Mud Crabs|