5 Other deep-water sharks and skates from the Northeast Atlantic (ICES Subareas 4 14)

Transcription

1 136 ICES WGEF REPORT 16 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, pallid skate Bathyraja pallida, Richardson's skate Bathyraja richardsoni, Bigelow's skate Rajella 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 rabbitfish, particularly common chimaera Chimaera monstrosa in Norway (114 t in 12, 177 t in 13) 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 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 The fishery in 15 Since 10, 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 15 were very low or zero. As most of these species are taken as bycatch in mixed fisheries, it is likely that discarding has increased.

2 ICES WGEF REPORT ICES advice applicable No species-specific advice is given for the shark and skate species considered here. The ICES Advice for 13 also included an Opinion on modification to the list of deep-sea sharks (ICES Advice 13, Book 11, Section ) Management applicable Prior to 10 in EC waters, a combined TAC was set for a group of deep-water sharks. These include Portuguese dogfish Centroscymnus coelolepis, leafscale gulper shark Centrophorus squamosus, birdbeak dogfish Deania calcea, kitefin shark Dalatias licha, greater lanternshark Etmopterus princeps, velvet belly Etmopterus spinax, black dogfish Centroscyllium 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 microcephalus, 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 10, TACs in all areas were reduced to zero with an allowance for bycatch of 10% of 09 TACs. For 11, the bycatch allowance was reduced to 3% of 09 TACs and in 12 no allowance for bycatch was permitted. This remained the status quo in 13 and 14. In 14, 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 was also fixed for 15 and 16. Deep-water skates are included in EU TACs for Skates and Rays Rajidae. In EU waters 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 Landings Landings in 15 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 08, annual landings from this fishery were around 100 t however, in 09, Portuguese landings reduced to 2 t. Other countries reported very small landings from Subareas 6 and 7 since 02. 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, particularly in Portuguese landings from Subarea 10 (Pinho, 10 WD). Misidentification problems were detected in mainland Portuguese landing ports with two different species of Deania being observed in catches: D. calcea and D. profundorum.

3 138 ICES WGEF REPORT 16 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 05, the total reported landings for all subareas reached 4 t; however this declined to 66 t in 08 and zero by 09. 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, 09 WD; Vinnichenko et al., 10 WD). However landings data from this fishery were not made available to the working group since. 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 05 and were principally derived from the UK registered deep-water gillnet 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 99. French annual landings peaked at about 400 t in 01 and have since declined. These landings are mainly from Division 5.b and Subarea 6. Iceland reported few landings, all from Division 5.a. The largest annual landings reported by Spain came from Subarea 12 in 00 (85 t) and 01 (91 t), but recent data are lacking. Since 09, only Iceland reported catches of black dogfish, mainly from Subarea 5, but always in small amounts (1 t in 13). 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, Norway, UK (England and Wales), UK (Scotland) and Spain. Greatest landings are from Denmark. Landings began in 93, peaked in 98 at 359 t and have since declined. In recent years catches have mostly been reported by Norway, with a maximum of t in 13. 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, 09 WD; Vinnichenko et al., 10 WD). However landing data from this fishery were not made available to the working group since.

4 ICES WGEF REPORT Lantern sharks nei Etmopterus spp. Reported landings of lantern sharks nei are presented in Tables 5.6 and 5.9. Four European countries have reported landings from Subareas 4 7 and 9: France, UK (Scotland), Spain and Portugal. Portuguese landings mainly referred to Etmopterus spinax and Etmopterus pusillus, however only a very small proportion of the catches of these species is retained. Reported French landings began in 94, peaked at nearly 3000 t in 96 then declined by 99. 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 00, peaked at over 300 t in 01. Spanish landings data have not been available since 03. Few landings data have been reported since 03. Aiguillat noir This is a generic category only used by France (Tables 5.7 and 5.9) to record landings on small, deep-water squaliform sharks, mainly black dogfish Centroscyllium fabricii with smaller quantities of longnose velvet dogfish and lantern sharks. Reported landings started in 00 (249 t) then declined from 266 t in 01 to 1 t in 07, since when there have been no reported landings. Lowfin gulper shark Centrophorus lusitanicus Reported landings of this species in Portuguese area (ICES Subarea 9) in (Tables 5.8. and 5.9) are believed to refer to misidentified C. squamosus, C. coelolepis, S. ringens, D. calcea and D. profundorum (Serra-Pereira et al., WD 11; Lagarto et al., 13 WD). Norwegian skate Dipturus nidarosiensis The species is occasionally landed in three French ports mostly under the landing name "D. oxyrinchus" with the code RJO. The length frequency distribution of Dipturus nidarosiensis observed in the French landing are presented in Figure 5.1, individuals landed mostly come from the ICES Division 6.a. Other skates Surveys of French fish markets show that Rajella lintea, Rajella kukujevi, Rajella fyllae, Bathyraja spinicauda and Dipturus nidarosiensis are occasionally landed from ICES Division 6.a, but without specific landing names Discards Portugal (Azores) Discards data from the Azorean observer programme waere provided in Pinho and Canha (11 WD; Table 5.10). Since then, this information has not been updated. Portugal (mainland) Discards data from the Portuguese longline fishery were presented. Etmopterus spp. and C. crepidater are the species with higher percentages of discards along the timeseries (although C. crepidater was not sampled in 13). Other elasmobranchs were

5 140 ICES WGEF REPORT 16 rarely discarded (Prista et al., 14 WD). Estimates of percentage discarded by species from deep-water longlines and demersal bottom trawls are given in Table To evaluate the level of bycatch and discards of deep-water sharks in the Portuguese trammelnet fishery, a pilot study was undertaken in ICES Division 9.a (Moura et al., 15 WD). Results show that the fishery targeting anglerfish and operating at depths of m has a low frequency of occurrence of deep-water sharks (Table 5.12). Results further suggest that relatively higher frequencies of occurrence are likely to be observed deeper than 600 m, according to the depth ranges reported for most of these species. Spain The Spanish Discards Sampling Programme for Otter and Pair Bottom Trawl (OTB and PTB) fleets, covering ICES Subareas 6, 7, Division 8.c and 9 (North), started in 88; however, it did not have yearly continuity until 03. The sampling strategy and the estimation methodology used follows the Workshop on Discard Sampling Methodology and Raising Procedures guidelines (ICES, 03) and more detail of this applied to this area was explained in Santos et al. (10). Preliminary estimates of Spanish deepwater elasmobranch discards (03 14) are presented in Table Quality of the catch data Unknown quantities of deep-water species are landed in grouped categories such as sharks nei, Dogfish nei and Raja rays nei, so catches presented here are probably underestimated. Landings reported by UK vessels for 03/04 were considered to be unreliably identified and were therefore amalgamated into a mixed deep-water shark (siki) category together with Portuguese dogfish and leafscale gulper shark. Since 05/06, UK landings for most species were considered to be more reliably identified; however, reported landings of gulper shark are still considered to be unreliable and have been added to landings of siki sharks. As result of restrictive quotas for deep-water sharks, landings of these species from the Portuguese longline fishery in Division 9.a may have been misidentified. In addition, it is likely that the available landing data for some species may be unreliable due to problems with species identification. For example gulper shark Centrophorus granulosus may be sometimes confused with morphologically similar species such as C. lusitanicus and C. harrissoni (Compagno et al., 05). Also White et al. (13) demonstrated that C. niaukang is an ontogenic stage of C. granulosus Discard survival No data available to the Working Group. 5.4 Commercial catch composition No new information is available. 5.5 Commercial catch and effort data No new information is available.

6 ICES WGEF REPORT Fishery-independent surveys ICES Subarea 6 The Scottish deep-water trawl survey has operated from 96 to 15 at depths of m along the continental slope between approximately 55 N and 59 N (see Neat et al., 10 for details). Neat et al. (15) analysed catches of deep-water elasmobranch species from Scottish deep-water trawl survey ICES Subarea 7 The Spanish survey on the Porcupine Bank (SpPGFS-WIBTS-Q4) in ICES Divisions 7.c and 7.k covers an area from longitude 12 W to 15 W and from latitude 51 N to 54 N following the standard IBTS methodology for the western and southern areas (ICES, 10). The sampling design is a random stratified (Velasco and Serrano, 03) with two geographical sectors (North and South) and three depth strata (< 300 m, m and m). Haul allocation is proportional to the strata area following a buffered random sampling procedure (as proposed by Kingsley et al., 04) to avoid the selection of adjacent 5 5 nm rectangles. More details on the survey design and methodology are presented in Ruiz-Pico et al. (14 WD) and Fernández-Zapico et al. (15 WD). Results for 15 are presented in Ruiz-Pico et al. (16 WD) The most abundant deep-water shark species in biomass in these surveys were Deania calcea (birdbeak dogfish), Deania profundorum (arrowhead dogfish), Scymnodon ringens (Knifetooth dogfish), Etmopterus spinax (velvet belly lantern shark), Dalatias licha (Kitefin shark), and Hexanchus griseus (bluntnose six-gill shark) ICES Divisions 8.c and 9.a The Spanish IEO Q4-IBTS survey in the Cantabrian Sea and Galician waters covers this area annually since 83 (except in 87), obtaining abundance indices and length distributions for the main commercial species and elasmobranchs. More details on the survey design, methodology and results can be found in Ruiz-Pico et al. (15 WD; Fernández-Zapico et al., 16 WD). In 15, elasmobranchs made up ca. 6% of the total fish catch. All species showed a decrease in biomass with regard to 14., A new vessel (R/V Miguel Oliver) is in use since 13. In the Portuguese survey (PtGFS-WIBTS-Q4) taking place off southwestern and southern coasts the deep-water elasmobranch with highest catches is D. profundorum. This survey is designed for crustacean species and operates to depths of 700 m ICES Subarea 10 Data from the Azorean bottom longline survey (ARQDACO(P)-Q1) in Division 10.a2 were given in Pinho (14 WD). Deania spp. were the most representative (abundant) species in the survey. C. crepidater was common, but much less abundant. Other species occurred in very low numbers (averaging 1 4 individuals per year). Depth range sand length composition data are available. It should be noted that the gear configuration used is not adequate for sampling all the species (Pinho, 14 WD). 5.7 Life-history information Several recent studies have provided relevant biological information:

7 142 ICES WGEF REPORT 16 Moore et al. (13) provide length of first maturity of Centroscymnus crepidater (57.2 cm total length (TL) for males and 75.4 cm TL for females) and of Apristurus aphyodes (49.0 cm TL for males and 56.9 cm TL for females) from the Rockall Trough. Rodriguez-Cabello et al. (13) showed that the distribution of Galeus murinus extended southward, to Cantabrian Sea, and Neoraja caerulea and northwards the distribution of Neoraja iberica. Coelho et al. (14) conducted demographic analysis of E. spinax using an age-based model. They found that the population should be stable if there is a two year reproductive cycle, but would be declining if there is a three year cycle, highlighting why an accurate knowledge of reproductive periodicity is important. Moura et al. (14) found that Deania calcea was spatially segregated by size, sex and maturity. Pregnant females inhabit shallower and warmer waters; large immature specimens were deeper, and mature males were more broadly distributed than mature females, supporting the possibility of sex-biased dispersal. 5.8 Exploratory assessments analyses of relative abundance indices The exploratory assessments below are all based on analyses of relative abundance indices in fishery-independent surveys Spanish Porcupine Bank (SpPGFS-WIBTS-Q4) and Spanish IEO Q4-IBTS survey Abundance indices for some deep-water elasmobranchs caught in the Spanish survey on the Porcupine Bank (SpPGFS-WIBTS-Q4) and the Spanish IEO Q4-IBTS survey in the Cantabrian Sea and Galician waters are presented below. Information for E. spinax, H. griseus, S. ringens, D. calcea and D. profundorum is presented however the majority of these species are usually found at deeper waters than those covered by the Spanish IEO Q4-IBTS survey (additional hauls) and thus the abundance indices must be treated with caution Scottish deep-water trawl survey in Division 6.a Neat et al. (15) analysed catches of deep-water elasmobranch species from the Scottish deep-water trawl survey in Division 6.a. Selected results are presented below. Scientific dual-warp bottom-trawls with rock-hopper ground gear (for details see Neat et al., 10) were carried out at 527 sites along the deep-water slopes, banks and seamounts of the Rockall Trough, to the west of Scotland. Surveys were carried out from at depths of m. In 96 FRV Scotia IV was in service, but was replaced by FRV Scotia V in 98. Most of the records in the database derive from Scotia V and in particular from surveys carried out in September that used the Jackson BT- 184 deep-water bottom trawl. For species distribution mapping all data were used, but for statistical analyses over time only data from 98 onwards (Scotia V only) and only data collected with the same trawl net (Jackson BT184) from the continental slope during the month of September were used. For some species of the genus Apristurus there has been an ongoing taxonomic debate, for example A. melanoasper was only formally described in 04. Therefore time-series analyses were restricted to two of the more common Apristurus species (A. aphyodes and A. microps) that did not pose identification problems or nomenclature changes during the survey period.

8 ICES WGEF REPORT For each species, the relationship between number caught per hour of trawling and depth were visually inspected and a core depth range established that included >99% of individuals. All hauls within this range (including those with zero catch of that species) were used to generate estimates of catch per unit of effort. As a consequence of variable depth ranges of each species, the sample sizes (number of hauls) vary from species to species. Distribution maps for each species were produced using ARC GIS. To assess areas of relatively high abundance in close proximity to each other, the Hot Spot Analysis tool in ARC GIS was used. This calculates the Getis-Ord Gi statistic for each feature in a dataset. The resultant values indicate where features with either high or low values cluster spatially based on the proximity of neighbouring features. The analysis highlights samples with a high value that are surrounded by other features with high values as well. It is a useful tool for visualising the spatial distribution of high abundance data. General additive models (Zuur et al., 09) were used to analyse trends over time, as the relative abundance of most species showed non-linear relationships with depth and over time. The GAM uses a smoothing function to account for the non-linear relationships. Latitude was also included in the model as a continuous variable as there was often a weak but significant relationship. Negative binomial or Tweedie variance structures were used to account for the variable occurrence of hauls with zero catch. GAMs were applied to eleven species that were regularly encountered from year-to-year. Several species were too infrequently sampled to analyse Summary of trends by species Birdbeak dogfish Deania calcea and Arrowhead dogfish Deania profundorum In the SpPGFS-WIBTS-Q4 survey series, these two species were traditionally registered together, but have been better separated since 12, as reported in previous documents (Ruiz-Pico et al., 14). The most recent survey indicates that both species decreased both its abundance and biomass in 15, in relation to 14. D. calcea remains representing the most percentage of the Deania genus in the area (Figure 5.2). Analysing both species together, 15 showed a decrease both in biomass and in number, after the peak of catch registered in 14, the highest value for the historical series. (Ruiz-Pico et al., 16 WD). In the Spanish IEO Q4-IBTS survey in the Cantabrian Sea and Galician waters, D. calcea and D. profundorum were recorded together until 09. D. profundorum was first separately recorded in 09 (Sanjuan et al., 12), To avoid confounding effects between the two species results previous to 09 combine the two species and were referred as Deania spp. (Figure 5.3). Biomass values of D. calcea in 15 in ICES Divisio 8.c were similar to 14. This species was not caught in ICES Division 9.a(N). D. profundorum increased in both divisions, although in greater proportion in Division 9.a(N) (Fernández-Zapico et al., 16 WD). The abundance of Deania calcea in hauls within the core depth range of m on the Scottish slope has fluctuated generally between 0.7 and 2.2 ind.h 1 with no evident trend (since 98; Table 5.14). The catch rate in 13 was anomalously high at 5 ind.h 1, the highest in the series. Preliminary analyses by Neat et al. (15) showed a significant positive trend (p = 0.001) over time (Figure 5.4). The results of this analysis should be considered as preliminary and indicative only of general trends.

9 144 ICES WGEF REPORT 16 Knifetooth dogfish Scymnodon ringens In the Spanish Porcupine survey (SpPGFS-WIBTS-Q4) a slight decrease in biomass and abundance of S. ringens was observed in 15 (Figure 5.5). (Ruiz-Pico et al., 16 WD). Biomass values in the Spanish IEO Q4-IBTS survey in the Cantabrian Sea and Galician waters are very low. These values have fluctuated since 04 with no evident trend (Figure 5.6). In 15 the value was similar to the one observed in 14, slightly above the maximum value of the series registered in 13 (Fernandez-Zapico et al., 16 WD). Velvet belly lantern shark Etmopterus spinax Both the biomass and abundance indexes of E. spinax in the Spanish Porcupine survey (SpPGFS-WIBTS-Q4) decreased in 15, in relation to to the peak registered in 14 (Figure 5.7; Ruiz-Pico et al., 16 WD). In the Spanish IEO Q4-IBTS survey in the Cantabrian Sea and Galician waters, the biomass index shows an increasing trend since 96 with the strong increase in recent years (06 13); the highest value was registered in 13 (Figure 5.8). In 15, about 94% of the biomass of this scarce elasmobranch was found in hauls deeper than 500 m (Fernandez-Zapico et al., 16 WD). In Division 9.a(N), E. spinax was more frequent in hauls deeper than 500m than in 14. The relative abundance of Etmopterus spinax derived from Scottish deep-water survey at depths from 300 to 1100 m has varied with no overall trend (between 3 10 ind.h 1 ) since 98 (Table 5.15 and Figure 5.9). Preliminary analyses using GAM with Tweedie distribution suggest no significant trend over time (Neat et al., 15). Greater lantern shark Etmopterus princeps The relative abundance of this species between depths of m from Scottish deep-water survey has been variable (averaging 3 ind.h 1 ), for the past 14 years (Table 5.16; Figure 5.10). Preliminary analyses using GAM with Tweedie distribution suggest no trend over time (Neat et al., 15). Bluntnose six-gill shark Hexanchus griseus Stratified biomass indicex of H. griseus in the Spanish Porcupine survey decreased in 15, after a increasing trend observed in the preceeding years, (Ruiz-Pico et al., 16 WD). On the contrary, abundance has increased in 15 (Figure 5.11). The absence of large individuals, which contributed to the peak observed in 14, explain the drop of the biomass this last survey (Ruiz-Pico et al., 16 WD). In the Spanish IEO Q4-IBTS survey in the Cantabrian Sea and Galician waters, the biomass of H. griseus increased in relation to 14, although not reaching the maximum value of the historical series observed in 13. Figure 5.12) (Fernandez-Zapico et al., 16 WD). The relative abundance of H. griseus between depths of m from Scottish deepwater survey averaged <1 ind.h 1 over the past 14 years (Table 5.17). There was an anomalously high catch of 15 individuals in 08. Black dogfish Centroscylium fabricii The relative abundance of C. fabricii between depths of m from Scottish deepwater survey has fluctuated with no trend (ca. 5 ind.h 1 ) since 98 (Table 5.18; Figure 5.13). Variability of the catch rates is high, wityh occasional large catches recorded.

10 ICES WGEF REPORT Preliminary analyses using GAM with Tweedie distribution suggest no significant trend over time (Neat et al., 15). Longnose velvet dogfish Centroscymnus crepidater The relative abundance of this species between depths of m from Scottish deep-water survey has been variable (averaging 5 ind.h 1, but with occasional very high catches) for the past 14 years (Table 5.; Figure 5.14). Preliminary analyses using GAM with Tweedie distribution suggest a significant negative trend (p <0.001) over time (Neat et al., 15). Small-eye cat shark Apristurus microps The relative abundance of this species at depths of m from Scottish deepwater survey was, on average, 1 ind.h 1 over the past 14 years (Table 5.; Figure 5.15). Pale catshark Apristurus aphyodes The relative abundance of this species between depths of m from Scottish deep-water survey was on average 4 ind.h 1 for the past 14 years (Table 5.21; Figure 5.16). Preliminary analyses using GAM with Tweedie distribution suggest an increasing trend over time (p < 0.001) (Neat et al., 15). Deep-water skates and rays Skates are caught infrequently in the Scottish deep-water survey, and the total numbers of each species (blue pygmy skate Neoraja caerulea, Mid-Atlantic skate Rajella kukujevi, round skate Rajella fyllae, deep-water skate Rajella bathyphila, Bigelow's skate Rajella bigelowi, Richardson's skate Bathyraja richardsoni, Jensen's skate Amblyraja jenseni and Krefft's skate Malacoraja kreffti) each year are shown in Table Stock assessment No formal assessments are undertaken for these stocks Quality of assessments No assessments undertaken Reference points No reference points have been proposed for any of these species Conservation considerations The recent European Red List of mairne fishes considers Centrophorus granulosus to be Critically Endangered, Centrophorus lusitanicus, Echinorhinus brucus, Deania calcea and Dalatias licha as Endangered; and Centrophorus uyato and Oxynotus centrina as Vulnerable (Nieto et al., 15) Management considerations No management advice is given in References Coelho, R., Alpizar-Jara, R., and Erzini, K. 14. Demography of a deep-sea lantern shark (Etmopterus spinax) caught in trawl fisheries of the northeastern Atlantic: Application of

11 146 ICES WGEF REPORT 16 Leslie matrices with incorporated uncertainties. Deep Sea Research Part II: Topical Studies in Oceanography. DOI: /j.drs Compagno, L., Dando, M. and Fowler, S. 05. Sharks of the World. Collins Field Guide. Harper Collins Publishers, London, 368 pp. Fernández-Zapico, O., Velasco, F., Baldó, F., Rodríguez-Cabello, C., Ruiz-Pico, S. 15. Results on main elasmobranch species captured during the Porcupine Bank (NE Atlantic) bottom trawl surveys. Working document ICES WGEF, 25 pp. Fernández-Zapico, O., Velasco, F., Rodríguez-Cabello, C., Punzón, A., Preciado, I., Ruiz-Pico, S., Blanco, M. 16. Results on main elasmobranch species captured in the bottom trawl surveys on the Northern Spanish Shelf. Working document ICES WGEF, 22 pp. ICES. 03. Report of ICES Workshop on Discard Sampling Methodology and Raising Procedures. Charlottenlund, Denmark, 2 4 September 03. ICES. 10. Manual for the International Bottom Trawl. Surveys in the Western and Southern Areas, Revision III. 64 pp. Kingsley, M.C.S., Kanneworff, P., and Carlsson, D.M. 04. Buffered random sampling: a sequential inhibited spatial point process applied to sampling in a trawl survey for northern shrimp Pandalus borealis in West Greenland waters. ICES Journal of Marine Science, 61: Lagarto, N., Moura, T., Farias, I. and Figueiredo, I. 13. Sampling information from deep-water sharks caught in the black scabbardfish fishery from mainland Portugal. Working Document ICES WGEF 13; 3 pp. Moore, D., Neat, F., and McCarthy I. 13. Population biology and ageing of the deep water sharks Galeus melastomus, Centroscymnus crepidater and Apristurus aphyodes from the Rockall Trough, North-east Atlantic. Journal of the Marine Biological Association of the UK, 93: Moura, T., Fernandes, A., Figueiredo, I., Alpoim, R., Azevedo, M. 15. Results from the pilot study on the Portuguese trammel nets fishery targeting anglerfish in ICES Division IXa. Working Document to ICES Working Group on Elasmobranch Fishes (WGEF), Lisbon, 15; 7 pp. Moura, T., Jones, E., Clarke, M., Cotton, C., Crozier, P., Daley, R., Diez, G., Dobby, H., Dyb, J., Fossen, I., Irvine, S., Jakobsdottir, K., López-Abellán, L., Lorance, P., Pascual-Alayón, P., Severino, R., and Figueiredo, I. 14. Large-scale distribution of three deep-water squaloid sharks: Integrating data on sex, maturity and environment. Fisheries Research, 157: Neat, F. C., Burns, F., Jones, E. and Blasdale, T. 15. The diversity, distribution and status of deep-water elasmobranchs in the Rockall Trough, north-east Atlantic Ocean. Journal of Fish Biology, 87: Neat, F. C., Kynoch, R.J., Drewery, J. and Burns, F. 10. Deepwater survey manual. Marine Scotland Science: Nieto, A., Ralph, G. M., Comeros-Raynal, M. T., Kemp, J., Garcia Criado, M., et al. 15. European Red List of marine fishes. Luxembourg: Publications Office of the European Union. Pinho, M. R. 10. Update landings of elasmobranches from the Azores (ICES Area X). Working Document ICES WGEF, 10-; 10 pp. Pinho, M.R. 14. Resuming elasmobranchs survey data from the Azores (ICES X). Working Document to the ICES Working Group on Elasmobranch Fishes, Lisbon, June ; 18 pp. Pinho, M. R. and Canha, A. 11. Elasmobranchs discards from the Azores longline fishery (ICES Subdivision Xa2). ICES Working Document WGEF. Prista, N., Fernades, A., Maia, C., Moura, T., and Figueiredo I. 14. Discards of elasmobranchs in the Portuguese fisheries operating in ICES Division XIa: Bottom otter trawl, deepwater

12 ICES WGEF REPORT set longlines, set gillnet and trammel net fisheries (04 13). WD WGEF 14, Lisbon, June 14; pp. Rodriguez-Cabello, C., Pérez, M., and Sanchez, F. 13. New records of chondrichthyans species in the Cantabrian Sea (southern Bay of Biscay). Journal of the Marine Biological Association of the UK, 93: Ruiz-Pico, S., Velasco, F., Baldó, F., Rodríguez-Cabello, C., Fernández-Zapico, O. 14. Results on main elasmobranch species captured during the Porcupine Bank (NE Atlantic) bottom trawl surveys. Working Document ICES WGEF; 26 pp. Ruiz-Pico, S., Velasco, F., Baldó, F., Rodríguez-Cabello, C., Punzón, A., Preciado, I., Fernández- Zapico, O., Blanco, M. 15. Results on main elasmobranch species captured in the bottom trawl surveys on the Northern Spanish Shelf. Working Document ICES WGEF; pp. Ruiz-Pico, S., Baldó, F., Velasco, F., Rodríguez-Cabello, C., Fernández-Zapico, O. 16. Results on main elasmobranches species from 01 to 15 Porcupine Bank (NE Atlantic) bottom trawl surveysworking Document ICES WGEF; 29 pp. Santos J., H. Araújo, I. Salinas and N. Pérez. 10. Elasmobranches Results from Spanish Discard Sampling Programme. ICES WGEF.10; 6 pp. Serra-Pereira, B., Moura, T., Farias, I., Maia, C., Lagarto, N., Veiga, N., and Figueiredo, I. 11. Information on sharks, rays and skates landings from mainland Portugal. Working Document ICES WGEF; 13 pp. Velasco, F., and Serrano, A. 03. Distribution patterns of bottom trawl faunal assemblages in Porcupine Bank: Implications for Porcupine surveys stratification design. Working Document presented to IBTSWG 03; pp. Vinnichenko, V.I. and Fomin K. Yu. 09. Russian research and fisheries of sharks and skates in the Northeast Atlantic in 08. Working document presented to ICES WGEF 09; 12 pp. Vinnichenko, V.I., Dolgov, A.V. and A.S.Yurko. 10. Russian Research and Fisheries of Sharks and Skates in the Northeast Atlantic in 09. Working Document to WGEF WD White, W., Ebert, D., Naylor, G., Ho, H-C., Clerkin, P., Verissimo, A., and Cotton, C. 14. Revision of the genus Centrophorus (Squaliformes: Centrophoridae): Part 1-Redescription of Centrophorus granulosus Bloch and Schneider), a senior synonym of C. acus Garman and C. niaukang Teng. Zootaxa, 3752 (1): Zuur, A., Ieno, E. N., Walker, N., Saveliev, A. A., Smith, G. M. 09. Mixed effects models and extensions in ecology with R. Springer; 574 pp.

13 148 ICES WGEF REPORT 16 Table 5.1. Other deep-water sharks and skates from the Northeast Atlantic. Working Group estimates of landings of gulper shark. Portugal Spain total n.a n.a

14 ICES WGEF REPORT Table 5.2. Other deep-water sharks and skates from the Northeast Atlantic. Working Group estimates of landings of birdbeak dogfish. Ireland Spain UK (England and Wales) UK(Scotland) France Portugal Total n.a n.a n.a

15 150 ICES WGEF REPORT 16 Table 5.3. Other deep-water sharks and skates from the Northeast Atlantic. Working Group estimates of landings of longnose velvet dogfish. France UK (Scotland) UK (England and Wales) Portugal Spain Total n.a n.a n.a n.a

16 ICES WGEF REPORT Table 5.4. Other deep-water sharks and skates from the Northeast Atlantic. Working Group estimates of landings of black dogfish. France Iceland UK (England and Wales) Spain Total n.a n.a n.a. + n.a Table 5.5. Other deep-water sharks and skates from the Northeast Atlantic. Working Group estimates of landings of velvet belly. Norway Denmark UK (Scotland) UK (England and Wales) Spain Total

17 152 ICES WGEF REPORT Table 5.6. Other deep-water sharks and skates from the Northeast Atlantic. Working Group estimates of landings of lantern sharks NEI. France Spain Portugal UK Scotland total

18 ICES WGEF REPORT Table 5.7. Other deep-water sharks and skates from the Northeast Atlantic. Working Group estimates of landings of aiguillat noir. France total Table 5.8. Other deep-water sharks and skates from the Northeast Atlantic. Working Group estimates of landings of Centrophorus lusitanicus. Portugal total 07 n.a. 08 n.a

19 154 ICES WGEF REPORT 16 Table 5.9. Other deep-water sharks and skates from the Northeast Atlantic. Working Group estimates of landings by species. Species Gulper shark Birdbeak dogfish Black dogfish Longnose velvet dogfish Velvet belly Lantern shark NEI Aiguillat noir Angular roughshark Lowfin gulper shark Knifetooth dogfish Arrowhead dogfish TOTAL

20 ICES WGEF REPORT Table 5.9. Continued. Species Gulper shark Birdbeak dogfish Black dogfish Longnose velvet dogfish Velvet belly Lantern shark nei Aiguillat noir Angular Roughshark Lowfin gulper shark Knifetooth dogfish Arrowhead dogfish n.a. n.a. n.a. n.a TOTAL

21

22 ICES WGEF REPORT Table Other deep-water sharks and skates from the Northeast Atlantic. Discards of deep-water shark species (numbers) recorded by Azores observers Species Damaged Non commercial Undersized Not identified Total Centrophorus granulosus 2 2 Dalatias licha Deania calceus Etmopterus spinax Hexanchus griseus Table Other deep-water sharks and skates from the Northeast Atlantic. Frequency of occurrence (%) of deep-water sharks in the discards of the hauls sampled on board the Portuguese fisheries by gear type: crustacean bottom otter trawl - OTB_CRU; demersal fish bottom otter trawl - OTB_DEF; deep-water set longline fishery that targets black scabbardfish LLS_DWS (04 12). --- indicates no occurrence; NA, information not available by species. Fishery YEAR OTB_CRU Deania calcea NA Centrophorus granulosus NA Deania profundorum NA Etmopterus spp OTB_DEF Deania calcea NA Etmopterus spp LLS_DWS Centroscymnus crepidater Centroscymnus cryptacanthus NA Deania calcea NA Squalus spp NA Deep-water sharks nei NA Deania profundorum NA Etmopterus spp Scymnodon ringens NA

23 158 ICES WGEF REPORT 16 Table Other deep-water sharks and skates from the Northeast Atlantic. Number and catch weight of anglerfish (Lophius spp.) and number of sharks by 100 m depth strata sampled from the pilot study on the trammelnet fishery targeting anglerfish in Portuguese waters (Division 9.a) (12 14). Lophius spp. combines Lophius piscatorius and Lophius budegassa. N = number of sampled specimens; West, estimated weight (based on length weight relationships). From Moura et al. (15 WD). Total Depth stratum (m) Species n n n n n n n Centroscymnus crepidater* Scymnodon ringens* Chlamydoselachus anguineus* Dalatias licha* Centrophorus granulosus* 1 1 Deania calcea* Etmopterus spinax* 4 4 Etmopterus pusillus Squaliformes NI 1 1 Mitsukurina owstoni 2 2 Galeus atlanticus 1 1 Galeus spp Scyliorhinus canicula Mustelus spp. 1 1 Isurus oxyrhinchus 1 1 Prionace glauca Galeorhinus galeus 3 3 Lophius spp. (n) Lophius spp. (weight, kg) > No hauls * sharks included in the EU deep-water shark list.

24 ICES WGEF REPORT Table Other deep-water sharks and skates from the Northeast Atlantic. Spanish discard data of deep-water shark species. In bold weight discarded (tons.) of demersal elasmobranches and below in italics. CV of estimations by fishing ground. For detailed information see (Santos et al., 10). Fishing Ground Species Celtic Sea (Subareas 6 7) Dalatias licha Deania calcea Etmopterus spinax Galeus melastomus Iberian Waters (Divisions 8.c 9.a) Dalatias licha Deania calcea Etmopterus spinax Galeus melastomus Table Other deep-water sharks and skates from the Northeast Atlantic. Summary data for Birdbeak dogfish D. calcea from Scottish deep-water survey. (N hauls- number of hauls; N fishnumber of fishes; Mean NpH mean number per hour). Year N hauls N fish Mean NpH proportion of positive hauls

25 160 ICES WGEF REPORT 16 Table Other deep-water sharks and skates from the Northeast Atlantic Summary data for velvet belly Etmopterus spinax from Scottish deep-water survey. (N hauls- number of hauls; N fishnumber of fishes; Mean NpH mean number per hour). Year N hauls N fish Mean NpH proportion of positive hauls Table Other deep-water sharks and skates from the Northeast Atlantic. Summary data for greater lantern shark Etmpterus princeps from Scottish deep-water survey. (N hauls- number of hauls; N fish- number of fishes; Mean NpH mean number per hour). Year N hauls N fish Mean NpH proportion of positive hauls

26 ICES WGEF REPORT Table Other deep-water sharks and skates from the Northeast Atlantic. Summary data for bluntnose six-gill shark Hexanchus griseus from Scottish deep-water survey. (N hauls- number of hauls; N fish- number of fishes; Mean NpH mean number per hour). YEAR N HAULS N FISH MEAN NPH PROPORTION OF POSITIVE HAULS Table Other deep-water sharks and skates from the Northeast Atlantic. Summary data for black dogfish Centroscymnus fabricii from Scottish deep-water survey. (N hauls- number of hauls; N fish- number of fishes; Mean NpH mean number per hour). Year N hauls N fish Mean NpH proportion of positive hauls

27 162 ICES WGEF REPORT 16 Table 5.. Other deep-water sharks and skates from the Northeast Atlantic. Summary data for long-nosed velvet dogfish Centroscymnus crepidater from Scottish deep-water survey. (N haulsnumber of hauls; N fish- number of fishes; Mean NpH mean number per hour). Year N hauls N fish Mean Nph proportion of positive hauls Table 5.. Other deep-water sharks and skates from the Northeast Atlantic. Summary data for mouse catshark Galeus murinus from Scottish deep-water survey. (N hauls- number of hauls; N fish- number of fishes; Mean NpH mean number per hour). Year N hauls N fish Mean NpH proportion of positive hauls

28 ICES WGEF REPORT Table Other deep-water sharks and skates from the Northeast Atlantic. Summary data for pale catshark Apristurs aphyodes from Scottish deep-water survey..(n hauls- number of hauls; N fishnumber of fishes; Mean NpH mean number per hour) YEAR N HAULS N FISH MEAN NPH PROPORTION OF POSITIVE HAULS Table Other deep-water sharks and skates from the Northeast Atlantic. Total number of deepwater skates caught in the Scottish deep-water survey across all depths by year (blue pygmy skate Neoraja caerulea, Mid-Atlantic skate Rajella kukujevi, round skate Rajella fyllae, deep-water skate Rajella bathyphila, Bigelow's skate Rajella bigelowi, Richardson's skate Bathyraja richardsoni, Jensen's skate Amblyraja jenseni and Krefft's skate Malacoraja kreffti). Year N. caerulea R. kukukujevi R.fyllae R.bathyphila R.bigelowi B. richardsoni A. jenseni M. krefti Total

29 164 ICES WGEF REPORT 16 Number of individuals observed Undeterminate Female Male adult Male Immature n= Total length (cm) Figure 5.1. Other deep-water sharks and skates from the Northeast Atlantic. Length frequency distribution of Dipturus nidarosiensis observed in the French landing and coming from ICES Subareas 6 7. kg haul Biomass % 10 % Year Number Ind haul % 10 % Year Figure 5.2. Other deep-water sharks and skates from the Northeast Atlantic. Birdbeak dogfish Deania calcea biomass index (Kg haul 1 ) from the Spannish Porcupine survey (SpPGFS-WIBTS- Q4) time-series (01 15). Boxes show parametric standard error of the stratified biomass index. Lines mark bootstrap confidence intervals (a = 0.80, bootstrap iterations = 1000). From Ruiz-Pico et al. (16 WD).

30 ICES WGEF REPORT Deania spp Mean biomass (Kg) g) 0. Hexanchus griseus Figure 5.3. Other deep-water sharks and skates from the Northeast Atlantic. Catches by weight of Deania spp. In north Spanish shelf bottom trawl surveys (Spanish IEO Q4-IBTS survey) 04 15, including all additional hauls out of the standard stratification (>500 m) during the last decade. From Fernández-Zapico et al. (16 WD). Figure 5.4. Other deep-water sharks and skates from the Northeast Atlantic. Results of GAM analysis of catches of birdbeak dogfish Deania calcea in Scottish deep-water trawl survey from Neat et al. (15) showing (a) Box-whisker plot of numbers per hour for each year. (b) Smoothed function of relative abundance of across years. (c) Smoothed function of relative abundance of across depths. (d) Distribution of abundance across the survey area graded from large red dots that indicate hauls of high abundance in close proximity to other hauls of high abundance to small blue dots that indicate hauls of low abundance in close proximity to other hauls of low abundance.