Bathyraja brachyurops, Broadnose Skate

Abstract

The Broadnose Skate (Bathyraja brachyurops) is a medium-sized (to 125 cm total length) skate that occurs in the Southeast Pacific and Southwest Atlantic Oceans from Biobío, Chile, south around Cape Horn and north to Rio Grande do Sul, Brazil, including the Falkland Islands (Malvinas). It is demersal on the inner continental shelf and upper slope at depths of 28?604 m. This skate is taken as bycatch in inadequately-managed demersal trawl and longline fisheries throughout most of its range. In the Argentina-Uruguay Common Fishing Zone, it is taken as bycatch but recorded with all other coastal skates. Species-specific catch time-series for Argentinian fisheries are unavailable, but overall skate landings were minimal prior to 1994 before rising rapidly and reaching a peak in 2007 and then dropping again until 2017. It is one of the main species captured in the Falkland Islands (Malvinas) multispecies target skate fishery, where the catch-per-unit-effort time-series suggests its relative abundance increased over the period 1994?2013. In Chile, it is a retained bycatch of the commercial longline fishery targeting Yellownose Skate, and in trawl fisheries targeting Chilean Hake and crustaceans. Overall, due to the level of fishing pressure that this skate is exposed to throughout much of its geographic range, its limited refuge at depth, its continued common presence in fisheries catches, and its moderately productive life history that allows it to withstand some fishing pressure, combined with an increasing trend in the Falkland Islands (Malvinas) and declines in skates in general elsewhere in its range, it is suspected that a population reduction of 20-29% has occurred over the past three generations (42 years). Therefore, the Broadnose Skate is assessed as Near Threatened, nearly meeting the threshold under criterion A2bd.