Blue Swimmer Crab

Blue swimmer crab, previously known as sand crab, Portunus pelagicus.

Department of Primary Industries and Fisheries Fishnote on Blue Swimmer Crabs

Commercial catch of blue swimmer crab. Data extracted from http://chrisweb.dpi.qld.gov.au 30 June 2004, with permission of Department of Primary Industries and Fisheries.

The management of the fishery has been judged ecologically sustainable under the Environment Protection and Biodiversity Conservation (EPBC) Act, and has been approved as a Wildlife Trade Operation until the next review of the managment of the fishery by the Australian Government Department of Environment and Heritage (DEH) in late 2007.

Although blue swimmer crabs are found throughout Queensland waters, both the commercial and recreational fisheries are concentrated in southern Queensland.
Since 1998, commercial fishing effort has expanded into offshore waters.

The current level of take would appear to be sustainable given that there is no evidence of a decline in catch-per-unit-effort (CPUE). However, this assessment could change as the fishery expands into the offshore areas and if effort increases significantly.

Interactions with threatened species is an issue including entanglement in the pot lines. Entanglement could be minimised by additional requirements on attendance and standardised gear specifications.

While the fishery is relatively well managed, DEH has identified a number of risks that must be managed to ensure that their impacts are minimised:

• Potential for activation of significant latent effort in the fishery;
• The amount and impact of recreational harvest of blue swimmer crab and the ability of existing management measures to adequately control recreational harvest;
• Reliance on unvalidated catch and effort data;
• Risk of and inability to detect areas at risk of overfishing;
• Lack of fishery specific objectives, performance indicators and performance measures; and
• Uncertainty about the extent and robustness to fishing of offshore stocks.

(Assessment of the Queensland Blue Swimmer Crab Pot Fishery, Australian Government Department of Environment and Heritage 2004)

Tonnes: 92
Boats: 264
Days: 8,077
Data extracted from http://chrisweb.dpi.qld.gov.au 30 June 2004, with permission of Department of Primary Industries and Fisheries.

$650,400
Data extracted from http://chrisweb.dpi.qld.gov.au 30 June 2004, with permission of Department of Primary Industries and Fisheries.

175 tonnes in 1999 (Williams 2002)

Most of the fishery is south of the Great Barrier Reef, from the NSW border to Bundaberg. There is a lower intensity of fishing along the length of the Great Barrier Reef. Blue swimmer crabs are taken from the edges of sandbanks in depths of more than 3m, and in open water. In the Great Barrier Reef World Heritage Area, harvest is both by pot and trawl. (Williams 2002).

A variety of crab pots, collapsible traps, dillies (baited tangle nets) and nets are used. See Commercial Crab Fisheries in Queensland (DPI&F).

The fishery is legislated for under Queensland’s Fisheries Regulations 1995.

Area: Blue swimmer crabs can be taken from all tidal areas except no-take zones as specified by the Great Barrier Reef Marine Park Authority and waters closed to fishing by Department of Primary Industries and Fisheries (DPI&F).

Gender: Only male blue swimmer crabs can legally be harvested.

Size: A minimum size of 11.5cm across the carapace from notch to notch applies.

Gear: No more than 50 crab pots or other apparatus can be used at a time by commercial fishers. For crabs taken while trawling, there is a limit of 100 in Moreton Bay and 500 elsewhere. Recreational fishers may use up to 4 pots or dillies per person.

The Queensland population of blue swimmer crabs was assessed between 1998 and 2001 by Queensland Department of Primary Industries and Fisheries (DPI&F): Fisheries biology and assessment of the blue swimmer crab (Portunus pelagicus) in Queensland.

DPI&F also undertakes long-term monitoring of fished stocks of blue swimmer crabs.

Williams L. (ed). 2002. Queensland's fisheries resources. Current condition and recent trends 1988-2000. Department of Primary Industries, Brisbane.