|Scientific Name:||Amblyraja hyperborea|
|Species Authority:||(Collett 1879)|
Raja hyperborea Collett, 1879
|Taxonomic Notes:||This species can be confused with other Amblyraja species with different distributions, such as Amblyraja georgiana (M. Stehmann pers. comm). In the northwest Atlantic, it is easily confused with Jensen' s skate (A. jenseni). Refer to Bigelow and Shroeder (1953), Jensen (1948) and Stehman and Burkel (1984).|
|Red List Category & Criteria:||Least Concern ver 3.1|
|Assessor/s:||Kulka, D.W., Barker, A.S., Pasolini, P. & Orlov, A.|
|Reviewer/s:||Dulvy, N.K.D., Haywood, M. & Valenti, S.V. (Shark Red List Authority)|
A deepwater skate very widely distributed, found in the North Atlantic, Southwest and East Pacific and off southern Australia in the East Indian Ocean. Occurs from 260 to 2,500 m, primarily at depths greater than most fisheries along lower continental slopes and therefore has apparently limited interaction with human threats. There is no current fishery interest. Reaches a maximum size of about 1 m, and appears to live exclusively at temperatures below 4º C. Very little is known of the life history parameters, although this is a medium to large skate, which may be exhibit similar characters to other unproductive deepwater skates. In the northwest Atlantic, this species has been taken occasionally in research trawls and in deepwater commercial fisheries off Canada. Caught commonly during surveys on the slope of the eastern Norwegian Sea and more recently in bottom trawl surveys of the Svalbard archipelago. Given that this species is primarily distributed outside the range of current fishing activity and has a wide geographic range, it is assessed as Least Concern. Continued monitoring of catches and expanding deepwater fisheries, and the collection of life history data should be a priority.
|Range Description:||Widespread along lower continental slopes. In the Northeast Atlantic, this species is found from the southeastern part of the Barents Sea (Novaya Zemliya Isl.) and Spitsbergen to the Greenland-Iceland-Faroe-Shetland Ridge to northern Norway) and the Svalbard archipelago (Paz 2003) (East Greenland Shelf, Faroe Plateau, Barents Sea). In the Northwest Atlantic, it occurs in Davis Strait between southwestern Greenland and Canada. Recently a small number of records were reported as far south as the Grand Banks in Canadian waters. However, some of these records may be confused with A. jenseni. Also reported from the Davis Strait (D. Kulka pers. comm). In the Southeast Atlantic, it is found along the southern tip of South Africa. In the Eastern Indian Ocean, it is found off southern Australia. In the Southwest Pacific it occurs in New Zealand and in the Eastern Pacific it is found in Costa Rica, Panama, Colombia, and Ecuador.|
Native:Australia; Canada; Colombia; Costa Rica; Ecuador; Faroe Islands; Greenland; Iceland; New Zealand; Panama; South Africa; United Kingdom (Great Britain)
|FAO Marine Fishing Areas:||
Atlantic – northeast; Atlantic – northwest; Atlantic – southeast; Indian Ocean – eastern; Pacific – eastern central; Pacific – northwest; Pacific – southeast; Pacific – southwest
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||Bottom trawl surveys in the Barents Sea from October to December 1998-2001 reported annual mean catches of this species of 0.1 to 1.0 fish per hour, and maximum catch of 83 fish per hour (Dolgov et al. 2005a). It was caught commonly during research cruises conducted on the slope of the eastern Norwegian Sea from 1984 to 1987 and in 1995 (Skjæraasen and Bergstad 2001). In the Spanish bottom trawl survey carried out on the Svalbard archipelago in 2003 at a depth range of 500 to 1,464 m A. hyperborea is recorded as one of the main species (Paz 2003).|
|Habitat and Ecology:||
This species is found in deep water (260 to 2,500 m). In Canadian waters, average depth observed was 1,200 m (rarely greater than 900 m) where the deepest survey sets occurred only as deep as 1,550 m. Oviparous, depositing eggs (81 to 125 mm long and 50 to 80 mm wide) on the bottom. Length on hatching is 16 to 18 (Bigelow and Schroeder 1953). Maximum size is reported as 106 cm (Last and Stevens 1994), although the maximum recorded size off Canada is smaller (63 cm TL: D. Kulka pers. obs).
In Norwegian waters the highest frequency of catches observed was at depths between 1,050 to 1,250 m. In the deepest areas sampled 2,000 to 2,050 m no catches were made, suggesting a lower limit to its depth range (Skjæraasen and Bergstad 2001). This species appears to live almost exclusively at temperatures below 4ºC (Bigelow and Schroeder 1953). There, they were associated with bottom temperatures of about 3.5°C (D. Kulka pers. comm). In the Barents Sea Arctic skate prefers bottom temperatures about 0°C (Dolgov et al. 2005a). They are benthic feeders with a diet consisting primarily of teleost fish, but also including a variety of benthic invertebrates.
Taken as bycatch in deepwater trawl and longline fisheries.
In the Barents Sea it is taken in trawl fisheries targeting Cod and Haddock at depths 300 m, and longline fisheries targeting mainly Blue Catfish (Anarhichas denticulatus) and cod at depths 300 m (Dolgov et al. 2005b). These long-lines fisheries operate at depths from 130 to 847 m. Average bycatch rates in the longline fishery were 10 to 25 fish (or 35 to 75 kg) per 1,000 hooks, and this species was estimated to constitute approximately 20% of total long-line catches (Dolgov et al. 2005b). However, it should be noted that the uncertainty of the estimates from this method is high (approximately ±45%).
Preliminary estimates indicate that total annual skate by-catch in these fisheries is 723 to 1,891 tons, and thorny skate composes the great majority of catches (90 to 95% of the total skate catch). Skate catches are mainly discarded in the Barents Sea, although in 2000, about 200 tons of thorny and arctic skate was landed (Dolgov et al. 2005b) and future trends should be monitored.
This is a deepwater species (260 to 2,500 m) that is distributed largely outside of the depth range of current fisheries, offering it refuge. Given the wide depth range this species is currently considered Least Concern. However, continued monitoring of catches and expanding fisheries should be a priority.
Also reported by fisheries observers have recorded them as an occasional bycatch in the Greenland halibut and shrimp fisheries in the Davis Strait (D. Kulka pers. comm).
Research to collect information on the biology, ecology, uses and fishery data of this species should be a priority.
The development and implementation of management plans (national and/or regional e.g., under the FAO International Plan of Action for the Conservation and Management of Sharks: IPOA-Sharks) are required to facilitate the conservation and sustainable management of all chondrichthyan species in the region.
|Citation:||Kulka, D.W., Barker, A.S., Pasolini, P. & Orlov, A. 2007. Amblyraja hyperborea. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.2. <www.iucnredlist.org>. Downloaded on 11 December 2013.|
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