The Roughtail Skate (Bathyraja trachura) is a medium-sized deepwater skate (to at least 98 cm total length) with a widespread distribution in the North Pacific Ocean, from northern 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 been recorded on continental and insular shelves and slopes at depths of 90–2,900 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 Roughtail Skate is a bycatch of fisheries targeting groundfish, including Pacific Cod (Gadus macrocephalus), Alaska Pollock (Gadus chalcogramma), and Greenland Halibut (Reinhardtius hippoglossoides). Across the Bering Sea and Aleutian Islands, it occurs mostly in the Eastern Bering Sea slope where abundance has been increasing since 2002. 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. The population is estimated to be increasing where it most commonly occurs (eastern Bering Sea) and it has deep water refuge across its range from current fishing activities. The Roughtail Skate is therefore assessed as Least Concern.

The Roughtail Skate is found in the North Pacific Ocean, from northern 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).

The species is rarely observed in research and commercial trawl surveys operating across its distribution in the Northwest Pacific (Orlov and Tokranov 2019). Skate abundance data are available for the Aleutian Islands, eastern Bering Sea (EBS) slope, and EBS shelf and are based on demersal trawl surveys conducted by the U.S. National Marine Fisheries Service (Ormseth 2020, Tribuzio et al. 2023). The Roughtail Skate is reported almost exclusively on the EBS slope. Total biomass estimates for the Roughtail Skate showed some increase in abundance from 1,624 to 2,239 tonnes between 2002 and 2016. The United States West Coast groundfish fishery (operating along the US Pacific Coast from the Washington−Canada border to the California−Mexico border) reported 0.31 metric tonnes of Roughtail Skate was retained and 433.52 metric tonnes was discarded between 2002 and 2014 (Jannot et al. 2021). Global population trend is estimated to be stable based on abundance data and refuge in deep water outside of current fishing activities.

The Roughtail Skate is demersal on continental and insular shelves and slopes at depths of 90–2,900 m (Last et al. 2016). In the Northeast Pacific (NEP), the Roughtail Skate is unique amongst other local deepwater skates in that it can inhabit mixed-substrate chemosynthetic environments (e.g., hydrothermal vents) as well as low-oxygen areas (Kuhnz et al. 2019). It reaches a maximum size of 98 cm total length (Dolganov and Tuponogov 1999, Winton et al. 2014). Size-at-maturity varies between the Eastern Bering Sea (EBS) and the NEP, with males mature at 74 cm TL and 77 cm TL, respectively and females mature at 80 cm TL and 74 cm TL, respectively (Davis et al. 2007, Winton et al. 2014). Reproduction is oviparous with a continuous reproductive cycle and an estimated size-at-birth of 9–16 cm TL (Last et al. 2016). Age-at-maturity and longevity are significantly higher in the EBS than NEP, with female age-at-maturity 25 years and 14 years, respectively and maximum age 36 years and 20 years respectively (Davis et al. 2007, Winton et al. 2014). Thus, in the EBS and NEP, generation length is 30.35 and 17 years, respectively.

The Roughtail Skate is a 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 Bathryaja 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, the 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 Roughtail 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 Roughtail Skate is 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 Roughtail Skate, there is limited species-specific information (Tribuzio et al. 2023). This species is mostly 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). Further research is needed on population size and trends, and life history, and catch rates should be monitored.