|Scientific Name:||Centrophorus squamosus|
|Species Authority:||(Bonnaterre, 1788)|
|Red List Category & Criteria:||Vulnerable A2bd+3bd+4bd ver 3.1|
|Assessor(s):||White, W.T. (SSG Australia & Oceania Regional Workshop, March 2003)|
|Reviewer(s):||Shark Specialist Group Australia & Oceania Regional Group (Shark Red List Authority)|
Centrophorus squamosus is an important component of deepwater fisheries (longline and trawl) off Ireland, Spain, Portugal and France. Quantitative CPUE data available for autoline catches in three ICES areas (Northeast Atlantic) show an 80 to 90% decline in three years, a 67 to 77% decline in four years, and a 20 to 69% decline in one year. Although this data is for C. squamosus and Centroscymnus coelolepis combined, these declines together with the acute vulnerability to exploitation of Centrophorus species as shown from the New South Wales fishery independent surveys, and the knowledge that C. squamosus is the more vulnerable of these two species in terms of life history, leads to this species being assessed as Vulnerable. A stock analysis will be available shortly from the 'DELASS' project in the North East Atlantic and more detailed CPUE data throughout its range is required. The flesh and liver are marketed from this species in many areas throughout its range, e.g., eastern Atlantic and eastern Indonesia. In the latter region, C. squamosus is landed frequently but in relatively low numbers and in a very limited artisanal fishery.
The catches of this species in Australia and Oceania are relatively low and do not represent a significant component of the squaloid catches in either southeastern Australia and New Zealand, but at present there is not enough information to assess it beyond Data Deficient in this region.
|Range Description:||Centrophorus squamosus has a wide distribution: in the eastern Atlantic from Iceland and the Atlantic slope to the Canary Islands, Senegal, Faeroes, Madeira, Azores, Gabon to Dem. Rep. Congo, Namibia, and western Cape of Good Hope (South Africa); western Indian Ocean (Natal off South Africa and the Aldabra Islands); eastern Indian Ocean (Tasmania and Victoria in Australia); the northwest Pacific, i.e., Japan, the western central Pacific (Philippines and Indonesia) and the southwestern Pacific, i.e. New Zealand and Australia (New South Wales) (Brito 1991, Last and Stevens 1994, Compagno and Niem 1998, Clarke et al. 2002, W. White, pers. obs.). The distribution for this species is considered to be more widespread in Australia than the records suggest (Last and Stevens 1994).
The level of fishing pressure needs to be examined in the various populations within its range to establish whether separate regional assessments are more suitable. For example, this species is caught in large numbers in the eastern Atlantic whereas they are not targeted or commonly caught as bycatch in Australian waters.
Native:Australia (New South Wales, Tasmania, Victoria); Congo; Congo, The Democratic Republic of the; Faroe Islands; Gabon; Iceland; Indonesia; Ireland; Japan; Namibia; New Zealand; Philippines; Portugal (Azores, Madeira); Senegal; South Africa; Spain (Canary Is.); United Kingdom
|FAO Marine Fishing Areas:|
Atlantic – southeast; Atlantic – eastern central; Atlantic – northeast; Indian Ocean – eastern; Indian Ocean – western; Pacific – southwest; Pacific – western central; Pacific – northwest
|Range Map:||Click here to open the map viewer and explore range.|
|Current Population Trend:||Decreasing|
|Habitat and Ecology:||Centrophorus squamosus is found demersally on the continental slopes at depths between 230 and 2,400 m, also pelagically in the upper 1,250 m of oceanic water in depths to 4,000 m (Compagno and Niem 1998). |
This species attains a maximum length of 1.6 m (Compagno and Niem 1998). Maturity is attained at approximately 100 cm total length (TL) in males and at approximately 125 cm in females (Girard and Du Buit 1999, Clarke et al. 2001). Centrophorus squamosus is ovoviviparous with 5 to 8 young born at a length between 35 and 43 cm (Last and Stevens 1994, Cox and Francis 1997). There is no apparent seasonal reproductive cycle in males (Girard et al. 2000).
A study of the age and growth of this species off the Atlantic Slope (off Ireland) provided age estimates of 21 to 70 years (Clarke et al. 2002), however, the validation of whether the rings were formed annually was not undertaken. This species presumably attains maturity at a relatively late age.
There is some preliminary data on the dietary compositions of this species (see Ebert et al. 1992).
Centrophorus squamosus is an important component of deep-water fisheries in certain areas within its range. This shark has been exploited commercially for many years. In Japan exploitation peaked during World War II, because of the high percentage of squalene in its liver, but quickly declined due to decreasing numbers caught. Deep-water fisheries (longlining and trawling) which catch large quantities of this species are found in the eastern Atlantic, e.g., off Ireland, Spain, Portugal and France (Iglesias and Paz 1995, Clarke et al. 2001, Girard and De Buit 1999). For example, this species is targeted heavily by the Portuguese deep-water longline fishery for which exploitation peaked in 1986 (600 tonnes) and has been steadily declining since then (Correia and Smith, in prep). The catches of the mixed trawl fishery off Rockall Trough and Porcupine Bank in the eastern Atlantic, which consist predominantly of this species and Centroscymnus coelolepis, increased from 302 tonnes in 1991 to 3,284 tonnes in 1996, and then declined to 1,939 tonnes in 1999 (ICES 2000). Although this suggests that the population is declining, this data cannot be directly related to fishing effort and it is therefore possible that fishing effort declined between 1996 and 1999. The French bottom trawl fishery has shown rapidly increasing landings of these species, i.e., 322 tonnes in 1990 and 2,939 tonnes in 1996 (Girard and De Buit 1999). Quantitative catch per unit effort are available for autoline catches in ICES Area VI: 218 (1997) to 24 (2000); 219 (1998) to 42 (2000) = 80 to 90% decline in three years. Area VII: 221(96), 56 (97), 51 (99), 73 (00) = 67 to 77% decline in four years. Area XII: 100 (1999), 78 and 31 (2000) = 20 to 69% decline in one year (SGRST 2002). Although this data is for C. squamosus and Centroscymnus coelolepis combined, the acute vulnerability to exploitation of Centrophorus spp has been shown from the New South Wales (NSW) fishery independent surveys (Graham et al. 2001), and C. squamosus is the more vulnerable of these two species in terms of life history.
Artisanal deep-water longline fisheries in eastern Indonesia, e.g., Java and Bali, also commonly land this species but often in low numbers (W. White, unpubl. data). The catches of this species in Australia and Oceania are relatively low and do not represent a significant component of the squaloid catch in both southeastern Australia and New Zealand, however more data is required.
The flesh and liver are marketed from this species in many areas throughout its range.
|Conservation Actions:||Detailed quantitative information on catch per unit effort for Centrophorus squamosus throughout its range is required to assess whether CPUE is declining. The only information available on catch rates records tonnage landed annually on Rockall Trough and Porcupine Bank in the eastern Atlantic, but this cannot be related to effort and, thus, cannot be used to determine whether population sizes are decreasing. A stock analysis will be available shortly from the DELASS project in the North East Atlantic. It should also be noted that due to the apparently long lifespan of this species, the recovery of a heavily fished population would probably require a long period of time.|
|Citation:||White, W.T. (SSG Australia & Oceania Regional Workshop, March 2003). 2003. Centrophorus squamosus. The IUCN Red List of Threatened Species 2003: e.T41871A10581731.Downloaded on 29 July 2016.|
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