|Scientific Name:||Achoerodus gouldii (Richardson, 1843)|
Labrus gouldii Richardson, 1843
Platychoerops muelleri Klunzinger, 1879
|Taxonomic Source(s):||Eschmeyer, W.N. (ed.). 2015. Catalog of Fishes. Updated 7 January 2015. Available at: http://researcharchive.calacademy.org/research/ichthyology/catalog/fishcatmain.asp. (Accessed: 7 January 2015).|
|Taxonomic Notes:||There have been problems arising from earlier records of distribution and management of this species in southern Australia due to confusion with A. viridis up until 30 years ago. Earlier records of large size of A. viridis in South Australia (Scott et al. 1974) refer to A. gouldii as does management aspects of Achoerodus in the Spencer Gulf (J.H. Choat pers. comm.. 2008).|
|Red List Category & Criteria:||Vulnerable A2bd ver 3.1|
|Assessor(s):||Choat, J.H., Gillanders, B. & Pollard, D.|
|Reviewer(s):||Sadovy, Y. & Liu, M.|
This species is only known from western and southern Australia. It is a large species that is found in highly accessible coastal habitat, and is the longest lived wrasse species. It is impacted by commercial and recreational fishing throughout its range. There have been declines of 60-90% over the past 20 years (since at least the 1990s) in at least a third of its range in the western part of its distribution, and assumed decline throughout its range due to fishing based on current low abundance in almost all of its range. Therefore, the overall population decline for this species is estimated to be at least 30% over the past 30 years, and will likely increase with continued commercial fishing. Although data on this species population and fishing effort is not available over the full three generation lengths (75 years), it is conservatively assumed that this species has been fished over the past 75 years, and the population trend before the 1980s was either stable or also in decline. It is therefore listed as Vulnerable. However, if older population or fishing data becomes available, this species may warrant reassessment as it may qualify for a higher threat category.
|Range Description:||This species is a large long-lived wrasse that is endemic to the southwestern and southern coasts of Australia. |
Its geographic range extends from the Geraldton on the central western Australian coast to Bass Strait in the east. As this species only occurs in reef environments, its area of occupancy is estimated to be approximately 100,000 km2. However, its distribution within this range is not uniform.
|FAO Marine Fishing Areas:|
Indian Ocean – eastern
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||Although the geographic range extends over 1,500 km along the Australian coastline, this species achieves relatively high abundances (seven individuals per 125 m2) at only one section of it geographical range around Esperance. In the northwestern part of its range, its abundance has declined since the 1990s between 60% (near Albany) and 93% (near Capes which is 635 km to the west of Esperance) based on recorded landings from commercial gillnet fisheries. Abundance in this western part of its range has correspondingly declined to about ~0.2 individuals per 125 m2 (DeLacy 2008). |
This species has experienced declines of 60-90% over the past 20 years (since at least the 1990s) in at least a third of its range in the western part of its distribution, and due to fishing throughout its relatively restricted range, is considered to be in very low abundances and declining in almost all of its range. The overall population decline for this species is therefore conservatively estimated to be at least 30% over the past 30 years (J.H Choat pers. comm. 2008), and may likely increase with continued commercial fishing in some parts of its range. It is conservatively assumed that the population trend before this time was either stable or also in decline from fishing, and the population was in the same if not in greater abundance.
|Current Population Trend:||Decreasing|
|Habitat and Ecology:||This is largest and longest-lived wrasse recorded, achieving a length of 170 cm and 70 years of age. The species is probably a protogynous hermaphrodite based on age and size distribution with a highly asymptotic growth pattern in both sexes and with males achieving a larger size than females. Spawning occurs in winter (June to October peaking in August). Recruitment to the reef habitat is highly episodic. Female maturity is late at 17 years, and occurs at a large size 653 mm TL with sex change at 35 years and at 830 mm TL. Based on a longevity of 70 years and first maturity of 17 years, average generation length is estimated to be 25 years. As this species does not typically change sex until a relatively old age (35-39 years), the abundance of the males of this protogynous hermaphrodite would be especially at risk of becoming depleted through fishing (Coulson et al. 2009).|
This species recruits onto more vegetated sheltered parts of reefs, and once they mature they move out onto deeper exposed coasts. Recruitment occurs on inshore reefs and larger individuals occur offshore on deeper reefs.
Natural mortality is 0.054/year (0.021-0.090/year), and fishing mortality 0.039/year (0.003-0.073/year) (Coulson et al. 2009).
|Generation Length (years):||25|
|Use and Trade:||This species is fished commercially and recreationally over its entire geographic range.|
This species is subject to both recreational and commercial fishing including bylines, spearing and commercial gill netting. The commercial fishery is dominated by gill netting which targets individuals between 428-1,162 mm and six to 70 years of age (Coulson et al. 2009). In Western Australia in 2002 the recreational fishery for wrasse species caught 192,000 individual fish (Henry and Lyle 2003) which have a smaller mean size than those taken in the commercial fishery. The blue groper component can account for 90% of the catch (DeLacy 2008). Direct observation and CPUE data (DeLacy 2008) and estimates of yield per recruit and fishing mortality (Coulson et al. 2009) demonstrate that this species is overfished in Western Australian waters.
In eastern Australia, this species has suffered such heavy fishing mortality in the 1980s, that the waters of that region were closed to commercial and recreational fishing for that species and still remain closed to spear and commercial fishing (Gillanders 1999).
However, monitoring of this species populations by fishery independent methods is sporadic. The rapid increase in the use of improved technology (e.g. echo sounders, GPS) for coastal fishing since 1990 shows the major impact of these instruments on fishing effort.
The current bag limit in Western Australia is one per day and size limit of greater than 500 mm TL. This species is not protected in Victoria and is still subject to commercial fishing there. It is totally protected in the Spencer Gulf and the Gulf of St. Vincent in southern Australia, although the records of this protection are linked to A. viridis but refer to A. gouldii.
Management plans need to be developed and implemented, especially in western Australia where there is very little protection. Although this species exists in reasonable numbers in Esperance, there are continuing records of poor catches along the central Western Australian coast, and more fishers are moving down there. Moreover, research is needed on the population numbers and range, threats, conservation measures and trends (J.H. Choat pers. comm. 2008).
Coulson, P.G., Hesp, S.A., Hall, N.G. and Potter, I.C. 2009. The western blue groper (Achoerodus gouldii), a protogynous hermaphroditic labrid with exceptional longevity, late maturity, slow growth, and both late maturation and sex change. Fishery Bulletin 107(1): 57-75.
DeLacy, C. 2008. Reef fish community structure and dynamics: response to human disturbance. School of Plant Biology, Faculty of Natural and Agricultural Sciences, The University of Western Australia.
Gillanders, B. 1999. Blue groper. In: N. Andrew (ed.), Under southern seas: the ecology of Australia’s rocky reefs, pp. 188-193. University of New South Wales Press Wales Press, Sydney.
Henry, G.W., and Lyle, J.M. 2003. The National Recreational and Indigenous Fishing Survey. NSW Fisheries Final Report Series: 48. Fisheries Research & Development Corporation and the Fisheries Action Program, Canberra, Australia.
IUCN. 2010. IUCN Red List of Threatened Species (ver. 2010.4). Available at: http://www.iucnredlist.org. (Accessed: 27 October 2010).
Pogonoski, J.J., Pollard, D.A. and Paxton, J.R. 2002. Conservation overview and action plan for Australian threatened and potentially threatened marine and estuarine fishes. Environment Australia, Canberra, Australia.
Scott, T.D., Glover, C.J.M. and Southcott, R.V. 1974. The marine and freshwater fishes of South Australia. Handbook of the flora and fauna of South Australia. South Australian Government, Adelaide.
|Citation:||Choat, J.H., Gillanders, B. & Pollard, D. 2010. Achoerodus gouldii. The IUCN Red List of Threatened Species 2010: e.T187520A8556943.Downloaded on 26 September 2017.|