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Crystal crab is a deep water (>400 m) crab species which is commercially caught off the west and south coasts of WA. The west coast component of the stock is certified by the Marine Stewardship Council (MSC) and has been assessed as sustainable.

Photo: Jason How, Department of Primary Industries and Regional Development, Western Australia

There is currently no information on the stock structure of crystal crab. A larval duration of 39 days reported for a congeneric Atlantic Ocean species [Perkins 1973] and preliminary movement information [Melville-Smith et al. 2007] suggest little potential mixing. However, as the majority of the catch (>95 per cent) comes from a small geographic area, it is considered a single stock for the purpose of this assessment. A research project has commenced to examine the genetic stock structure of crystal crabs from the west and south coasts of Western Australia. Here the assessment is presented at the biological stock level—West Coast (Western Australia).

West Coast

The stock status for crystal crab (Chaceon albus) is based on a weight of evidence approach using a range of empirical and modelled estimates of catch and catch rate. Annual assessments are undertaken which have been reviewed by the Marine Stewardship Council (MSC) since 2015.

The most recent stock assessment shows that the Crystal Crab total allowable catch (TAC) (154 tonnes (t)) on the west coast was achieved with a standardised catch rate (sCPUE; 1.72 kg / pot lift) above the threshold reference point of 1.66 kg / pot lift. There has been an increasing trend in the spatial extent of the fishery which, coupled with a low sCPUE, indicates that the stock may be subject to heavy fishing pressure. Additionally, there are a range of protections including protection of berried females and female maturation below the legal minimum size, which provide additional protection to the breeding stock.

The above evidence indicates that the biomass of this stock is unlikely to be depleted and that recruitment is unlikely to be impaired. The above evidence also indicates that the current level of fishing mortality is unlikely to cause the stock to become recruitment impaired. 

On the basis of the evidence provided above, the West Coast Crystal Crab is classified as a sustainable stock.

[Smith et al. 2004, Melville-Smith et al. 2007] 

Distribution of reported commercial catch of Crystal Crab

Commercial catch of Crystal Crab

2. Melville-Smith, R., Norton, S.M.G. and Thomson, A.W. (2007). Biological and Fisheries Data for Managing Deep Sea Crabs in Western Australia Final report to Fisheries Research and Development Corporation on Project No. 2001/055. Fisheries Research Report No. 165, Department of Fisheries, Western Australia, 248p.
3. Smith, KD, Potter, IC, Hesp, SA (2004). Comparisons between the reproductive biology of females of two species of deep sea crabs that live in different water depths. Journal of Shellfish Research 23:887-896
4. Smith, KD, Potter, IC, Hesp, SA (2004). Comparisons between the reproductive biology of females of two species of deep sea crabs that live in different water depths. Journal of Shellfish Research 23:887-896
5. The larval stages of the deep sea red crab, Geryon quinquedens Smith, reared under laboratory conditions (Decapoda: Brachyrhyncha) Fishery Bulletin. 71(1) 69-82.