The Deepsea Skate (Bathyraja abyssicola) is a large deepwater skate (to at least 175 cm total length) known from a widespread distribution across the North Pacific Ocean, from Honshu, Japan through to the Sea of Okhotsk and the Bering Sea down along the western coast of North America to the Gulf of California, Mexico. It has also been reported at the Galapagos Islands and has been recorded on the continental and insular slopes and abyssal plain at depths of 360–2,910 m. Across the North Pacific Ocean, skates are bycatch of industrial trawl, longline, and trap groundfish fisheries, and in some areas, skates comprise up to 10% of the total recorded biomass. The Deepsea Skate is infrequently caught in these fisheries and has significant deep refuge in deep water outside of current fishing activities. There is increasing international demand for skate products in countries including China, Japan, and Korea and this increased demand has increased skate retention and interest in developing skate targeted fisheries. There are catch limits set for skates (as a group) in Russian and United States waters. Areas of high skate egg density in the United States Bering Sea and Aleutian Islands are designated Habitats of Particular Concern which allows management intervention where fishing activity is deemed harmful to the habitat. Further research is needed on population size and trends, life history, and catch rates and developing fisheries should be closely monitored. There is no evidence of population decline and the species is not suspected to be close to reaching the population reduction threshold. The Deepsea Skate is therefore assessed as Least Concern.

The Deepsea Skate is widespread across the North Pacific Ocean, from Honshu, Japan through to the Sea of Okhotsk and the Bering Sea down along the western coast of North America to the Gulf of California, Mexico (Last et al. 2016, Love et al. 2021). It has also been reported at the Galapagos Islands (Cerutti-Pereyra et al. 2018).

No data are available on population size, trends, and structure of the Deepsea Skate. The species is rarely observed in research and commercial trawl surveys operating across its distribution in the North Pacific (Orlov and Tokranov 2019, Ormseth 2020). The United States West Coast groundfish fishery (operating along the US Pacific Coast from the Washington−Canada border to the California−Mexico border) reported 9.96 metric tonnes of discarded Deepsea Skate between 2002 and 2014 and no landed catch (Jannot et al. 2021). Global population trend is suspected to be stable based on refuge in deep water outside of current fishing activities.

The Deepsea Skate is demersal on the continental and insular slopes and abyssal plain at depths of 360–2,910 m, most commonly at 1,200–1,800 m (Orlov and Tokranov 2019, Sheiko and Fedorov 2000, Last et al. 2016). The preferred habitat is rocky reef substrate (Provost 2016). It reaches a maximum size of ~175 cm total length (TL) (Dolganov and Ginanova 2014, Love et al. 2021). Males mature at 118 cm TL and females mature at 127 cm TL (Provost 2016). Like other skates, the Deepsea Skate is oviparous and egg cases measure ~11 cm in length. Nothing else is known of its biology. There are no age parameters available and the congener of similar spatial range and the most similar depth range with age parameters is the Roughtail Skate (Bathyraja trachura) which has a female age-at-maturity of 25 years and maximum age of 36 years (Winton et al. 2014). Thus, generation length is estimated as 30.4 years.

The Deepsea Skate is a rare bycatch of commercial trawl, longline, and trap fisheries targeting groundfish, including Pacific Cod (Gadus macrocephalus), Alaska Pollock (Gadus chalcogramma), and Greenland Halibut (Reinhardtius hippoglossoides). It may be retained for the meat of the skate wings with retention rates of up to 30% in some fisheries. Post-release mortality is unknown but was 41% for deepwater Bathyraja species in southwest Atlantic trawl fisheries (Ellis et al. 2017).

In Japan, demersal trawl fisheries operate at depths of 50–500 m and effort has decreased markedly over the last three decades and is continuing to decline with fewer fishers and vessels participating in the fishery (NFMT 2017, S. Tanaka pers. comm. 2019). In Russia, fisheries usually operate to depths of 600–800 m (Ormseth and Matta 2011). There have been occasional experimental fisheries since 2016 that fish to 2,500 m depth (I.V. Volvenko unpub. data 2019) that may constitute a threat if expanded with the interest in developing targeted skate fisheries in the North Pacific. Skate fisheries in Russia are growing: the average annual skate catch reported to official statistics has grown nearly 3-fold, from 1,650 tonnes (t) in 2004–2008, 3,510 t in 2009–2013, and 4,860 t in 2014–2018; there is no species-specific skate catch reporting (Panchenko et al. 2020). In the eastern Bering Sea, skate egg cases, including the Deepsea Skate, are brought to the surface by commercial demersal trawl and longline fishing vessels targeting deepwater fish including Pacific Cod and Greenland Halibut (Stevenson et al. 2019). The Deepsea Skate is currently only commercially fished in the upper region of its bathymetric range and has significant refuge at depth from fisheries.

In Japan, skates are of low value and while there is some domestic consumption, skate wings are most likely exported to the Republic of Korea (H. Ishihara pers. comm. 2019). The meat may be processed into fish meat jelly which is used in some Japanese national dishes (Orlov and Volvenko 2022). In Russia, skates were previously discarded but more recently have been landed for export of wings to China, Japan, Korea, and the British Virgin Islands (Orlov and Volvenko 2022). International demand for skates by Korea is very high and has increased skate retention with Korea a major importer of skates from around the world (Hyun-Su et al. 2013). In the Bering Sea and Aleutian Islands fisheries, 27–51% (average 38%) of all skates were retained from 2011–2023, with larger individuals retained due to the higher market value, and while this may include the Deepsea Skate, there is limited species-specific information (Tribuzio et al. 2023). This species is discarded in the United States west coast groundfish fisheries (Jannot et al. 2021).

There is a Total Allowable Catch (TAC) for skates in Russian and United States waters. In Russian waters, the TAC has changed little since the 1990s and in the 2020s is 11,2000–11,3000 t (Orlov and Volvenko 2022). In the United States Bering Sea and Aleutian Islands (BSAI) regions this species is managed as a skate complex. The BSAI TAC for the complex is based on the age structured model for Alaska Skate (B. parmifera) and the combined other skate survey biomasses multiplied by an assumed natural mortality rate and has varied little from 2012–2023 and in 2023 was 27,441 t (Tribuzio et al. 2023). In 2015, six areas in the BSAI region of high skate egg density were designated Habitats of Particular Concern which allows management intervention where fishing activity is deemed harmful to the habitat. The 82 square nautical miles of habitat is split into different areas at the continental shelf/slope break, and aims to protect egg cases of various skate species. Targeted fishing for skates in the Gulf of Alaska has been prohibited since 2005 (Ormseth 2021).

On the United States west coast (Washington, Oregon, and California), ground fisheries are managed by a federal Groundfish Fishery Management Plan. Additionally, in California, a network of at least 29 marine protected areas provide some refuge from trawl fisheries (California Department of Fish and Wildlife 2015). In Japan, management measures have been implemented since the mid-1990s to control fishing effort that include total allowable catches, seasonal closures, and gear restrictions (White Paper 2019). The Galapagos Archipelago is covered by the 133,000 km² Galapagos Marine Reserve which prohibits industrial fishing and would provide the Deepsea Skate with refuge from trawl fisheries (Davos et al. 2007). Further research is needed on population size and trends, and life history, and catch rates should be monitored.