ICES WGEF REPORT 2017 | 147 5 Other deep-water sharks and skates from the Northeast Atlantic (ICES subareas 4–14) 5.1 Stock distributions This section includes information about deep-water elasmobranch species other than Portuguese dogfish and leafscale gulper shark (see Section 3), kitefin shark (see Section 4) and Greenland shark (see Section 24). Limited information exists on the majority of the deep-water elasmobranchs considered here, and the stock units for these species are unknown. The species and generic landing categories for which landing data are presented are: gulper shark Centrophorus granulosus, birdbeak dogfish Deania calcea, longnose velvet dogfish Centroscymnus crepidater, black dogfish Centroscyllium fabricii, velvet belly Etmopterus spinax, lantern sharks nei Etmopterus spp., and ‘aiguillat noir’ (which may include C. fabricii, C. crepidater and Etmopterus spp.) Fourteen species of skate (Rajidae) are known from deep water in NE Atlantic: Arctic skate Amblyraja hyperborea, Jensen's skate Amblyraja jenseni, Krefft's skate Malacoraja kreffti, roughskin skate Malacoraja spinacidermis, deep-water skate Rajella bathyphila, pal- lid skate Bathyraja pallida, Richardson's skate Bathyraja richardsoni, Bigelow's skate Ra- jella bigelowi, round skate Rajella fyllae, Mid-Atlantic skate Rajella kukujevi, spinytail skate Bathyraja spinicauda, sailray Rajella lintea, Norwegian skate Dipturus nidarosiensis, blue pygmy skate Neoraja caerulea and Iberian pygmy skate Neoraja iberica. Species such as Dipturus batis-complex and Leucoraja fullonica may also be found in deep water, but their main areas of distribution are in shallower waters and they are not considered in this section. One species of electric ray (Torpedo nobiliana) may also occur in the deep water of this area. Eight species of rabbitfish (Chondichthyes; Holocephali), including members of the genera Chimaera, Hariotta and Rhinochimaera are a bycatch of some deep-water fisheries and are sometimes marketed. The current zero-TACs for deep-water sharks, whose livers were used to extract squalene, may have led to the increased retention of rabbit- fish, particularly common chimaera Chimaera monstrosa in Norway (114 t in 2012, 177 t in 2013) to produce “ratfish oil”. Catches of Chimaeridae are included in the report of the ICES Working Group on Deep-water Fisheries Resources (WGDEEP). 5.2 The fishery 5.2.1 History of the fishery Most catches of other deep-water shark and skate species are taken in mixed trawl, longline and gillnet fisheries together with Portuguese dogfish, leafscale gulper shark and deep-water teleosts. 5.2.2 The fishery in 2016 Since 2010, EU TACs for deep-water sharks have been set at zero (see Section 5.2.4). Consequently, reported landings of most of the species covered in this chapter in 2016 were very low or zero. As most of these species are taken as bycatch in mixed fisheries, it is likely that discarding has increased. 148 | ICES WGEF REPORT 2017 5.2.3 ICES advice applicable No species-specific advice is given for the shark and skate species considered here. The ICES Advice for 2013 also included an “Opinion on modification to the list of deep-sea sharks” (ICES Advice 2013, Book 11, Section 11.2.2.1). 5.2.4 Management applicable Prior to 2010 in EC waters, a combined TAC was set for a group of deep-water sharks. These include Portuguese dogfish Centroscymnus coelolepis, leafscale gulper shark Cen- trophorus squamosus, birdbeak dogfish Deania calcea, kitefin shark Dalatias licha, greater lanternshark Etmopterus princeps, velvet belly Etmopterus spinax, black dogfish Cen- troscyllium fabricii, gulper shark Centrophorus granulosus, blackmouth catshark Galeus melastomus, mouse catshark Galeus murinus, longnose velvet dogfish Centroscymnus crepidater, frilled shark Chlamydoselachus anguineus, bluntnose six-gill shark Hexanchus griseus, sailfin roughshark Oxynotus paradoxus, Greenland shark Somniosus microcepha- lus, knifetooth dogfish Scymnodon ringens and deep-water catsharks Apristurus spp. In Subarea 12, rough longnose dogfish Deania histricosa and arrowhead dogfish Deania profundorum are also included on the list. In 2010, TACs in all areas were reduced to zero with an allowance for bycatch of 10% of 2009 TACs. For 2011, the bycatch allowance was reduced to 3% of 2009 TACs and in 2012 no allowance for bycatch was permitted. This remained the status quo in 2013 and 2014. In 2014, the list of sharks was updated to include all Centrophorus species and blackmouth catshark was removed, following comments from ICES (See Section 5.2.3). The zero-TAC for deep-water sharks has continued since 2015. Deep-water skates are included in EU TACs for “Skates and Rays Rajidae”. In EU wa- ters of divisions 6.a–b, 7a–c and 7e–k, Norwegian skate Dipturus nidarosiensis is one of a group of species which may not be retained on board and must be promptly released unharmed to the extent practicable. 5.3 Catch data 5.3.1 Landings Landings in 2016 were very low due to the zero TAC in force for deep-water sharks (Tables 5.1–5.9). Gulper shark Centrophorus granulosus Almost all landings of gulper shark (Tables 5.1 and 5.9) have been from the Portuguese longline fishery in Subarea 9. Until 2008, annual landings from this fishery were around 100 t, but in 2009, Portuguese landings reduced to 2 t. Other countries reported very small landings from Subareas 6 and 7 since 2002. Reported landings of this species by UK vessels in Subareas 6 and 7 are considered to be misidentified and these data are included in the Working Group estimates of “siki sharks”. Birdbeak dogfish Deania calcea Reported landings of birdbeak dogfish are presented in Tables 5.2 and 5.9. It is likely that landings reported as this species include other species in the same genus, particu- larly in Portuguese landings from Subarea 10 (Pinho, 2010 WD). Misidentification problems were detected in mainland Portuguese landing ports with two different spe- cies of Deania being observed in catches: D. calcea and D. profundorum. ICES WGEF REPORT 2017 | 149 Five European countries have reported landings from subareas 7 and 9 of birdbeak dogfish: Ireland, UK (England and Wales), UK (Scotland), Spain and Portugal. In 2005, the total reported landings for all subareas reached 194 t; however this declined to 66 t in 2008 and zero by 2009. Catches of this species by Russian deep-water longline fisheries in the Faroese Fishing Zone and other Northeastern Atlantic areas were reported in working documents to WGEF (Vinnichenko and Fomin, 2009 WD; Vinnichenko et al., 2010 WD). Landings data from this fishery were not subsequently available to the working group. Longnose velvet dogfish Centroscymnus crepidater Reported landings of longnose velvet dogfish are presented in Tables 5.3 and 5.9. It is likely that some landings of this species are also included in data for “siki sharks” (see Section 3) and in other mixed categories. European countries that have reported landings from subareas 6–9 are: UK (England and Wales), UK (Scotland), France, Spain and Portugal. Highest landings (400 t) were recorded in 2005 and were principally derived from the UK registered deep-water gill- net fleet. Reported landings have since declined to zero, probably as a result of the ban on deep-water gillnet fishing and reduced EU TACs for deep-water sharks. Black dogfish Centroscyllium fabricii Reported landings of black dogfish are presented in Tables 5.4 and 5.9. Landings of this species may also be included in the grouped category “Aiguillat noir” and other mixed categories, including siki sharks. Four European countries have reported landings, from divisions 4.a, 5.b and subareas 7 and 12: UK, Iceland, France and Spain. France reported the majority of the landings of black dogfish in the ICES area, starting to report landings in 1999. French annual landings peaked at about 400 t in 2001 and have since declined. These landings are mainly from Division 5.b and Subarea 6. Ice- land reported few landings, all from Division 5.a. The largest annual landings reported by Spain came from Subarea 12 in 2000 (85 t) and 2001 (91 t), but recent data are lacking. Since 2009, only Iceland has reported catches of black dogfish, mainly from Subarea 5, but always in small amounts (1 t in 2013). Velvet belly Etmopterus spinax Reported landings of velvet belly are presented in Tables 5.5 and 5.9. Five countries have reported landings of velvet belly, from subareas 2–4, 6–8 and 10: Denmark, Nor- way, UK (England and Wales), UK (Scotland) and Spain. Greatest landings are from Denmark. Landings began in 1993, peaked in 1998 at 359 t and have since declined. In recent years catches have mostly been reported by Norway, with a maximum of 19 t in 2013. Catches of this species by Russian deep-water longline fisheries in the Faroese Fishing Zone and other Northeastern Atlantic areas were reported in working documents to WGEF (Vinnichenko and Fomin, 2009 WD; Vinnichenko et al., 2010 WD). Landings data from this fishery were not subsequently available to the working group. 150 | ICES WGEF REPORT 2017 Lantern sharks nei Etmopterus spp. Reported landings of lantern sharks ‘nei’ are presented in Tables 5.6 and 5.9. Four Eu- ropean countries have reported landings from subareas 4–7 and 9: France, UK (Scot- land), Spain and Portugal. Portuguese landings mainly referred to Etmopterus spinax and Etmopterus pusillus, how- ever only a very small proportion of the catches of these species is retained. Reported French landings began in 1994, peaked at nearly 3000 t in 1996 then declined by 1999. There is doubt as to whether these landings are actually of this genus. French landings of Etmopterus princeps have been included in ‘siki’ sharks. Spanish landings began in 2000, peaked at over 300 t in 2001. Spanish landings data have not been available since 2003.