Sharks and Skates of Scotland Report: Jensen’s skate (Amblyraja jenseni)

Habitat 

Jensen’s skate have been recorded from 165 – 2550 m, however they are predominantly found at depths greater than 650 m and in waters ranging from 2.6–5.5 °C (Orlov and Cotton, 2015; Kulka et al., 2024). In the North Atlantic juveniles and adults have been found in similar depth ranges, with no significant difference in capture depth between males and females (Orlov and Cotton, 2015). The species is morphologically similar to (and often confused with) the Arctic skate Amblyraja hyperborea, however recent research has demonstrated a geographic and thermal separation between the species in the Northwest Atlantic, with the Jensen’s skate occupying waters to the South of the Davis Strait, and the Arctic skate occupying the colder Arctic waters to the North (in Baffin Bay) (Kulka et al., 2024).

Biology and Ecology

Data on the biology and ecology of Jensen’s skate are generally limited. Maximum size is reported as 112 cm. Males become sexually mature at around 90 cm TL, and females at 84 cm TL (Kulka et al., 2024). Jensen’s skate are oviparous and lay paired eggs that have horn-like projections. Size at hatching is around 14 cm. The juveniles and adults feed on small fishes and crustaceans (McEachran and Dunn, 1998).  

Human interactions

There is no target fishery for this species in the Northeast Atlantic and its habitat preference for waters deeper than 1000 m means that it is only occasionally taken as bycatch (Farrell et al., 2015; Orlov and Cotton, 2015). In Canada, Jensen’s skate is incidentally caught and discarded from the deepwater trawl, longline, and gillnet fisheries for Greenland Halibut (Reinhardtius hippoglossoides), and discard mortality is likely to be high in longline fisheries due to automatic hook removal (Kulka et al., 2020). Jensen’s skate are managed under a combined regional TACs for ‘skates and rays’ in Scottish waters as part of the Celtic Seas ecoregion and the Greater North Seas ecoregions. However, since the introduction of general measures to protect deep-water elasmobranchs (ban of static net fisheries below 600 m and trawls below 800 m; ICES 2024), the species is unlikely to be incidentally caught due to the depths at which it occurs.