Report of the Subgroup on Resource Status

Home , Megamouth shark, Raja africana, Smalleye catshark

COUNCIL OF Brussels, 4 November 2002 THE EUROPEAN UNION

13762/02

PECHE 167

COVER NOTE1 from : the Secretary-General of the European Commission signed by Mr Sylvain BISARRE, Director date of receipt : 31 October 2002 to : Mr Javier SOLANA, Secretary-General/High Representative Subject : Report of the Subgroup on Resource Status (SGRST) of the Scientific, Technical and Economic Committee for Fisheries (STECF) - Elasmobranchs Fisheries - Brussels, 23-26 September 2002

Delegations will find attached Commission document SEC(2002) 1160.

______

Encl.: SEC(2002) 1160

1 The text annexed hereto has been received by the General Secretariat of the Council in English only. 13762/02 mc 1 DG B III EN

COMMISSION OF THE EUROPEAN COMMUNITIES

Brussels, 29.10.2002 SEC(2002) 1160

COMMISSION STAFF WORKING PAPER

REPORT OF THE SUBGROUP ON RESOURCE STATUS (SGRST) OF THE SCIENTIFIC, TECHNICAL AND ECONOMIC COMMITTEE FOR FISHERIES (STECF)

ELASMOBRANCHS FISHERIES

Brussels, 23-26 September 2002

This report has not yet been approved by the Scientific, Technical and Economic Committee for Fisheries (STECF) and it does not necessarily reflect its views

EXECUTIVE SUMMARY

The subgroup was tasked to provide updated information on elasmobranch fisheries

The subgroup was also asked to provide an explicit ranking of stocks which are at different level of risk; such evaluation being based either on scientific stock assessment or, in absence of formalised scientific analysis, on subgroup’s expert judgement.

The subgroup noted that the knowledge base for these species is very poor, with even the most basic biological data missing for some species. There are few examples of species-specific catch and effort data available.

The subgroup considered that much progress had been made on stock assessment methodologies, owing to the EC-funded DELASS project.

The subgroup reviewed currently available information on elasmobranchs taken in Community fisheries and provided available information on stock status and vulnerability.

The subgroup updated the information on life history of some species and produced a ranking of species in several assemblages, in order of vulnerability. Further information on nine species, dealt with by the EC-funded DELASS project (CFP 99/055), will be available in the project final report (December 2002).

The subgroup considered that there are some clear examples of decreased abundance and disappearance of species from their former ranges.

The subgroup believed that most available data are very poor, and preclude accurate assessments of the stock status of many of the major elasmobranch species.

However the subgroup considered that accurate assessments of stock status and vulnerability of the majority of species will require further research.

The subgroup considered the range of management measures that are applicable to fisheries taking elasmobranchs and presents a discussion of the utilities of each.

The subgroup concluded with a series of recommendations concerning future research needs. In particular there will be need for a dedicated project to improve the availability of data in the short term. In the medium term, the Community Sampling Regulation should be modified to deal more appropriately with elasmobranchs. In addition, to assess the vulnerability of rare or by-catch species, an extensive small- scale programme is suggested.

TABLE OF CONTENTS

1. INTRODUCTION...... 1 1.1. TERMS OF REFERENCE ...... 1 1.2. PARTICIPANTS...... 2 1.3. METHODS AND WORKING STRATEGY OF THE SUBGROUP...... 2 2. ELASMOBRANCH FISHERIES...... 4 2.1. LIST OF SPECIES ...... 4 2.2. NE ATLANTIC (BALTIC, NORTH SEA, WESTERN WATERS, CECAF AREA, ETC.)...... 11 2.2.1. Coastal sharks and dogfish...... 11 2.2.1.1. Spurdog ...... 11 2.2.1.2. Catsharks and nursehounds ...... 15 2.2.2. Pelagic sharks...... 16 2.2.2.1. Basking shark...... 16 2.2.2.2. Blue shark...... 18 2.2.2.3. Porbeagle and tope ...... 19 2.2.3. Deep-water sharks...... 20 2.2.4. Skates and rays ...... 24 2.3. MEDITERRANEAN...... 30 2.3.1. Coastal fisheries ...... 32 2.3.2. Deep-sea fisheries...... 33 2.3.3. Pelagic fisheries ...... 33 2.3.4. Recreational fisheries ...... 35 2.4. EUROPEAN ELASMOBRANCH FISHERIES OUTSIDE EU WATERS ...... 37 3. BIOLOGICAL FEATURES ...... 42 3.1. SPECIES DISTRIBUTION AND STOCK STRUCTURE...... 42 3.1.1. Spurdog...... 42 3.1.2. Lesser spotted dogfish...... 42 3.1.3. Blue shark...... 43 3.1.4. Cuckoo ray...... 43 3.1.5. Thornback ray...... 43 3.1.6. Blackmouth catshark ...... 43 3.1.7. Portuguese dogfish ...... 44 3.1.8. Leaf-scale gulper shark ...... 44 3.1.9. Kitefin shark ...... 44 3.2. L-W RELATIONSHIPS, CONVERSION FACTORS ...... 44 3.2.1. Converstion factors...... 46 3.3. MATURITY ...... 50 4. SELECTIVITY PARAMETERS OF FISHING GEAR...... 51 4.1. DEMERSAL TRAWLS ...... 51 4.2. DEMERSAL LONGLINES ...... 52 4.3. DEMERSAL GILLNETS ...... 53 4.4. PELAGIC TRAWLS...... 53 4.5. PELAGIC LONGLINES ...... 53 4.6. PELAGIC GILLNETS...... 54 5. PAST AND RECENT TRENDS IN ABUNDANCE ...... 59 5.1. NORTH ATLANTIC...... 59 5.1.1. Spurdog (Squalus acanthias) in Sub-areas IV, VI and VII ...... 59 5.1.2. Lesser spotted dogfish (Scyliorhinus canicula) ...... 60 5.1.3. Portuguese dogfish (Centroscymnus coelolepsis)...... 61 5.1.4. Kitefin shark (Dalatias licha) ...... 63

5.1.5. Thornback ray (Raja clavata)...... 64 5.1.6. Cuckoo ray (Leucoraja naevus)...... 67 5.2. MEDITERRANEAN SEA ...... 69 6. STOCK STATUS...... 71 6.1. INTRODUCTION ...... 71 6.2. ASSESSMENT METHODS...... 71 6.2.1. Life table models...... 71 6.2.2. Surplus production models ...... 71 6.2.3. Growth models...... 72 6.2.4. Length-based methods ...... 72 6.2.5. Catch at age analysis...... 73 6.2.6. General Linear Models (GLM) analysis...... 74 6.2.7. Bayesian approach ...... 74 6.2.8. Overall conclusions ...... 74 6.3. VULNERABILITY AND STOCK STATUS...... 75 6.3.1. General...... 75 6.3.2. Stock status and vulnerability, as interpreted by ICES WG’s and for case story species for the DELASS project...... 76 6.3.2.1. Deepwater sharks ...... 76 6.3.2.2. Skates and rays...... 77 6.3.2.3. Coastal dogfish and catsharks ...... 78 6.3.2.4. Pelagic sharks...... 78 6.4. CONSERVATION STATUS...... 79 6.4.1. Introduction ...... 79 6.4.2. Levels of extinction risk ...... 79 6.4.3. Conservation status assessment methods...... 80 6.4.3.1. The IUCN Red List of Threatened Species ...... 80 6.4.3.2. Convention on International Trade in Endangered Species (CITES) ...... 80 6.4.4. Case studies: Porbeagle (Lamna nasus)...... 81 7. REPRODUCTION AND HABITAT...... 82

8. RESEARCH AND MONITORING NEEDS ...... 83 8.1. BIOLOGICAL DATA AND RESEARCH ...... 83 8.2. FISHERIES DATA AND RESEARCH...... 83 8.3. FISHERIES INDEPENDENT DATA ...... 84 8.4. GAPS IN CURRENT KNOWLEDGE AND FUTURE RESEARCH AND MONITORING ...... 84 8.4.1. Improvements to the EC Programme Framework Programme on Data Collection...... 84 8.4.2. Data requirements not met by Sampling Regulation ...... 85 8.4.3. Data requirements for assessment of vulnerability and conservation status...... 86 9. MANAGEMENT ...... 87 9.1. TOWARDS A COMMUNITY RESPONSE TO THE FAO PLAN OF ACTION ...... 87 9.1.1. Introduction ...... 87 9.1.2. Main international conventions relevant for elasmobranchs ...... 87 9.1.2.1. Biodiversity Convention (CBD) 1992...... 87 9.1.2.2. Convention on International Trade in Endangered Species (CITES) ...... 88 9.1.2.3. Intermediate Ministerial Meeting on the Integration of Fisheries and Environmental Issues, 1997 89 9.1.2.4. UN Agreement on Straddling Fish Stocks and Highly Migratory Fish Stocks...... 89 9.1.2.5. Bonn Convention on the Conservation of Migratory Species of Wild Animals (CMS)...... 90 9.1.2.6. Barcelona Convention for the Protection of the Mediterranean Sea (1976) ...... 90 9.1.2.7. Bern Convention on the Conservation of European Wildlife and Natural Habitats ...... 91 9.1.3. Aims of a shark plan as defined in the FAO IPOA-Sharks ...... 91 9.2. MANAGEMENT OF ELASMOBRANCH FISHERIES...... 93 9.2.1. Input controls...... 94 9.2.2. Output controls...... 94 9.2.3. Technical conservation measures...... 95 9.2.4. Closure of fishery...... 96

9.3. CASE STUDIES IN FISHERIES MANAGEMENT...... 96 10. RECOMMENDATIONS...... 98

11. REFERENCES...... 99

12. ANNEX - LIST OF PARTICIPANTS...... 102

1. Introduction STECF was requested by the Commission to organise, in 2002, a meeting dedicated to elasmobranch fisheries (SEC(2002)410). Principle aim of this meeting was to rearrange, update and comment as appropriate, available commercial, scientific and technical information on elasmobranch fisheries, and status of the stocks. This work, together with other sources of information as well as knowledge already available to the Commission, should present background information for the preparation of a Community Action Plan on Elasmobranchs.

Where not sufficient or robust scientific information was yet available, STECF has been requested to provide its expert judgement.

1.1. Terms of Reference In its terms of reference, supplied by the Commission, the subgroup was asked to:

1. Provide a comprehensive and updated overview of Community fisheries, both commercial and recreational, that catch elasmobranch stocks, either as target or by-catch species. These fisheries should be briefly described in terms of target species or group of species, fishing gear (average length, mesh size, hanging ratio etc.), fishing regime, catch composition, catch rates, average size of catches, size distribution of main target species, discards rate and its size composition, number of fishing vessels, fleet dynamics and characteristics. Fishing grounds of the main target species or group of species should be mapped.

2. Provide, by species, the allometric relationships between different portions of elasmobranchs body, including fins.

3. Provide a comprehensive and updated overview of maturity ogives, by length and/or age, for the main species identified.

4. Provide a comprehensive overview of breeding and spawning seasons (overall period and peak of spawning) and map breeding and nursery areas.

5. Provide a comprehensive and updated overview of lengths at first capture and selectivity parameters by hook size, mesh size, hanging ratio etc.

6. Provide past and recent trends in abundance of major elasmobranch stocks.

7. Provide the status of major elasmobranch stocks as well as an explicit ranking of stocks which are at different level of risk according to the most updated evaluation or expert judgment.

8. Identify, to describe and possibly map essential fish habitats and benthos communities either of shallow waters or of deep-sea bottoms, which are considered important somehow for the production of elasmobranch stocks.

9. Identify gaps in the current knowledge of fishery systems and assess the suitability for elasmobranchs of traditional stock assessment methods. Possible future monitoring and research needs should be highlighted.

10. Identify possible desirable management objectives and strategies for the various species or group of species and fisheries targeting elasmobranchs. Possible ways to improve inter-species selectivity, in order to reduce elasmobranch by-catches without affecting the target species, should be identified, if necessary.

11. Report case studies of management of elasmobranch fisheries undertaken at national level.

1.2. Participants The participants are listed below and contact details are given in Annex 1.

Invited experts Seret, Bernard Clarke, Maurice Vacchi, Marino Diez, Guzman Vinther, Morten Figueiredo, Ivone Maria

Fowler, Sarah STECF Secretariat Heessen, Henk (chair) Biagi, Franco (EC Commission) Pinho Rui, Mario

1.3. Methods and working strategy of the subgroup In order to assist the Commission to prepare a Community Plan of Action for the conservation and management of elasmobranchs, within the framework of the FAO- IPOA sharks, a group of specialists met at DG Fish from 23-26 September as an STECF subgroup on Resource Status (SGRST). In its terms of reference the Group was asked to compile and comment as appropriate, commercial, scientific and technical information. Moreover, scientific research needs should be pointed out.

Due to the fact that the meeting was organized at short notice in a busy period of the year, just between the NAFO Elasmobranch Symposium (Santiago de Compostela) and the ICES Annual Science Conference, the participants attended the meeting more or less unprepared. The Group relied heavily on the latest report of the ICES Study Group on Elasmobranch Fishes that met from 6-10 May 2002 (ICES, 2002a), and also on some material prepared under the DELASS contract.

DELASS (Development of Elasmobranch Assessments) is an EU funded study (CFP 99/055) which intends to develop elasmobranch assessments, focusing on 9 case study species that belong to different ecological groups of sharks and rays. DELASS runs from 1 January 2000 to 31 December 2002, and the final meeting will be held 4-6 November 2002 in Lisbon. As a consequence, the final conclusions of DELASS were not yet available, although these would have been very relevant for the present report.

This report was prepared in a short time. It may therefore contain certain inconsistencies. Also aspects may be mentioned, where the information available to the participants does not fully cover all that is available in the literature. Also, the list of references could not be fully completed.

In its terms of reference, the group was asked to produce a report on elasmobranch fisheries and elasmobranch stocks. Together with the Holocephali (chimaeras), elasmobranchs (sharks and rays) form the class of Chondrichthyes. When in this report “elasmobranchs” are mentioned, this term is understood to include not only sharks and rays, but also chimaeras, although taxonomically this is not correct.

Acknowledgements: The chair would like to thank all participants for their effort to provide all their contributions in time to prepare the report, and Maurice Clarke in particular, for his help after the meeting, in editing the report.

2. Elasmobranch fisheries The first section of this chapter gives an overview of elasmobranch species that occur in the Northeast Atlantic and in the Mediterranean Sea (Section 2.1). The next sections describe elasmobranch fisheries in the Northeast Atlantic (Section 2.2) and in the Mediterranean Sea (Section 2.3) and finally give some information of Community fisheries that catch elasmobranchs in other waters (Section 2.4).

2.1. List of species This list gives the scientific and the common name of all chondrichthyan fishes (Class Chondrichthyes) occurring in European waters: North-Eastern Atlantic, Mediterranean Sea, and Black Sea. The list is prepared according to L.J.V. Compagno’s classification (1999); question marks indicate that the taxonomic status is doubtful. Some species should probably be synonymized with other nominal species; others would represent valid species but should be assigned in another genus (e.g. Centrophorus uyato is most probably a valid species of Squalus !).

A. Sub-class ELASMOBRANCHII (sharks, skates and rays)

LIVING SHARKS

1. Order HEXANCHIFORMES (cow and frilled sharks)

1.1. Family CHLAMYDOSELACHIDAE (frilled sharks)

1.1.1. Chlamydoselachus anguineus Garman, 1884. Frilled shark.

1.2. Family HEXANCHIDAE (sixgill and sevengill sharks)

1.2.1. Heptranchias perlo (Bonnaterre, 1788). Sharpnose sevengill shark. 1.2.2. Hexanchus griseus (Bonnaterre, 1788). Bluntnose sixgill shark. 1.2.3. Hexanchus nakamurai Teng, 1962. Bigeye sixgill shark. 2. Order SQUALIFORMES (dogfish sharks)

2.1. Family ECHINORHINIDAE (bramble sharks)

2.1.1. Echinorhinus brucus (Bonnaterre, 1788). Bramble shark.

2.2. Family SQUALIDAE (dogfish sharks)

2.2.1. Squalus acanthias Linnaeus, 1758. Piked dogfish. 2.2.2. Squalus blainvillei (Risso, 1826). Longnose spurdog. 2.2.3. ? Squalus megalops (Macleay, 1881). Shortnose spurdog. 2.3. Family CENTROPHORIDAE (Gulper sharks)

2.3.1. Centrophorus granulosus (Bloch & Schneider, 1801). Gulper shark. 2.3.2. Centrophorus lusitanicus Bocage & Capello, 1864. Lowfin gulper shark. 2.3.3. Centrophorus squamosus (Bonnaterre, 1788). Leafscale gulper shark. 2.3.4. ? Centrophorus uyato (Rafinesque, 1810). Dwarf gulpershark 2.3.5. Deania calcea (Lowe, 1839). Birdbeak dogfish. 2.3.6. ? Deania mauli Cadenat & Blache, 1981 2.3.7. Deania profundorum (Smith & Radcliffe, 1912). Arrowhead dogfish. 2.4. Family ETMOPTERIDAE (lantern sharks)

2.4.1. Centroscyllium fabricii (Reinhardt, 1825). Black dogfish. 2.4.2. Etmopterus princeps Collett, 1904. Great lanternshark. 2.4.3. Etmopterus pusillus (Lowe, 1839). Smooth lanternshark. 2.4.4. Etmopterus spinax (Linnaeus, 1758). Velvet belly 2.5. Family SOMNIOSIDAE (sleeper sharks)

2.5.1. Centroscymnus coelolepis Bocage & Capello, 1864. Portugese dogfish. 2.5.2. Centroscymnus crepidater (Bocage & Capello, 1864). Longnose velvet dogfish. 2.5.3. Scymnodon ringens Bocage & Capello, 1864. Knifetooth dogfish. 2.5.4. Somniosus microcephalus (Bloch & Schneider, 1801). Greenland shark. 2.5.5. Somniosus rostratus (Risso, 1810). Little sleeper shark. 2.6. Family OXYNOTIDAE (rough sharks)

2.6.1. Oxynotus centrina (Linnaeus, 1758). Angular roughshark. 2.6.2. Oxynotus paradoxus Frade, 1929. Sailfin roughshark. 2.7. Family DALATIIDAE (kitefin sharks)

2.7.1. Dalatias licha (Bonnaterre, 1788). Kitefin shark. 2.7.2. Squaliolus laticaudus Smith & Radcliffe, 1912. Spined pygmy shark.

3. Order SQUATINIFORMES (angel sharks)

3.1. Family SQUATINIDAE. (angel sharks)

3.1.1. Squatina aculeata Dumeril, in Cuvier, 1817. Sawback angelshark. 3.1.2. Squatina oculata Bonaparte, 1840. Smoothback angelshark. 3.1.3. Squatina squatina (Linnaeus, 1758). Angelshark. 4. Order LAMNIFORMES (mackerel sharks) 4.1. Family ODONTASPIDIDAE (sand tiger sharks)

4.1.1. Carcharias taurus Rafinesque, 1810. Sand tiger shark. 4.1.2. Odontaspis ferox (Risso, 1810). Smalltooth sand tiger. 4.2. Family MITSUKURINIDAE (goblin sharks)

4.2.1. Mitsukurina owstoni Jordan, 1898. Goblin shark.

4.3. Family ALOPIIDAE (thresher sharks)

4.3.1. Alopias superciliosus (Lowe, 1839). Bigeye thresher. 4.3.2. Alopias vulpinus (Bonnaterre, 1788). Thresher shark. 4.4. Family CETORHINIDAE. (basking sharks)

4.4.1. Cetorhinus maximus (Gunnerus, 1765). Basking shark.

4.5. Family LAMNIDAE (mackerel sharks)

4.5.1. Carcharodon carcharias (Linnaeus, 1758). Great white shark. 4.5.2. Isurus oxyrinchus Rafinesque, 1810. Shortfin mako. 4.5.3. Isurus paucus Guitart Manday, 1966. Longfin mako. 4.5.4. Lamna nasus (Bonnaterre, 1788). Porbeagle shark. 5. Order CARCHARHINIFORMES (ground sharks) 5.1. Family SCYLIORHINIDAE (cat sharks)

5.1.1. Apristurus aphyodes Nakaya & Stehmann, 1998 5.1.2. Apristurus laurussoni (Saemundsson, 1922). Iceland catshark. 5.1.3. Apristurus microps (Gilchrist, 1922). Smalleye catshark. 5.1.4. Galeus atlanticus (Vaillant, 1888). Atlantic sawtail catshark. 5.1.5. Galeus melastomus Rafinesque, 1810. Blackmouth catshark. 5.1.6. Galeus murinus (Collett, 1904). Mouse catshark. 5.1.7. Scyliorhinus canicula (Linnaeus, 1758). Lesser spotted dogfish / Smallspotted catshark. 5.1.8. Scyliorhinus stellaris (Linnaeus, 1758). Nursehound

5.2. Family PSEUDOTRIAKIDAE (false catsharks) 5.2.1. Pseudotriakis microdon Capello, 1868. False catshark.

5.3. Family TRIAKIDAE (houndsharks) 5.3.1. Galeorhinus galeus (Linnaeus, 1758). Tope shark. 5.3.2. Mustelus asterias Cloquet, 1821. Starry smoothhound. 5.3.3. Mustelus mustelus (Linnaeus, 1758). Smoothhound. 5.3.4. Mustelus punctulatus Risso, 1826. Blackspot smoothhound. 5.4. Family CARCHARHINIDAE (requiem sharks) 5.4.1. Carcharhinus altimus (Springer, 1950). Bignose shark. 5.4.2. Carcharhinus brachyurus (Günther, 1870). Bronze whaler. 5.4.3. Carcharhinus brevipinna (Müller & Henle, 1839). Spinner shark. 5.4.4. Carcharhinus falciformis (Bibron, in Müller & Henle, 1839). Silky shark. 5.4.5. Carcharhinus limbatus (Valenciennes, in Müller & Henle, 1839). Blacktip shark. 5.4.6. Carcharhinus melanopterus (Quoy & Gaimard, 1824). Blacktip reef shark. 5.4.7. Carcharhinus obscurus (Lesueur, 1818). Dusky shark. 5.4.8. Carcharhinus plumbeus (Nardo, 1827). Sandbar shark. 5.4.9. Galeocerdo cuvier (Peron & Lesueur, in Lesueur, 1822). Tiger shark. 5.4.10. Prionace glauca (Linnaeus, 1758). Blue shark. 5.4.11. Rhizoprionodon acutus (Rüppell, 1837). Milk shark. 5.5. Family SPHYRNIDAE (hammerhead sharks)

5.5.1. Sphyrna lewini (Griffith & Smith, in Cuvier, Griffith & Smith, 1834). Scalloped hammerhead. 5.5.2. Sphyrna mokarran (Rüppell, 1837). Great hammerhead. 5.5.3. Sphyrna tudes (Valenciennes, 1822). Smalleye hammerhead. 5.5.4. Sphyrna zygaena (Linnaeus, 1758). Smooth hammerhead

LIVING BATOIDS (SKATES & RAYS)

6. Order PRISTIFORMES (sawfishes) 6.1. Family PRISTIDAE (sawfishes)

6.1.1. Pristis pectinata Latham, 1794. Smalltooth sawfish. 6.1.2. Pristis pristis (Linnaeus, 1758). Common sawfish.

7. Order RHINOBATIFORMES (guitarfishes)

7.1. Family RHINOBATIDAE (guitarfishes)

7.1.1. Rhinobatos (Glaucostegus) cemiculus St. Hilaire, 1817. Blackchin guitarfish. 7.1.2. Rhinobatos (Rhinobatos) rhinobatos (Linnaeus, 1758). Common guitarfish or violinfish. 8. Order TORPEDINIFORMES (electric rays)

8.1. Family TORPEDINIDAE (electric rays)

8.1.1. ? Torpedo (Torpedo) alexandrinis Mazhar, 1983. Alaxandria torpedo 8.1.2. Torpedo (Tetronarce) nobiliana Bonaparte, 1835. Great torpedo. 8.1.3. Torpedo (Torpedo) fuscomaculata Peters, 1855. Blackspotted torpedo. 8.1.4. Torpedo (Torpedo) marmorata Risso, 1810. Spotted torpedo. 8.1.5. Torpedo (Torpedo) torpedo (Linnaeus, 1758). Ocellate torpedo. 9. Order RAJIFORMES (skates)

9.1. Family ARHYNCHOBATIDAE (softnose skates)

9.1.1. Bathyraja pallida (Forster, 1967). Pallid skate. 9.1.2. Bathyraja richardsoni (Garrick, 1961). Richardson's skate. 9.1.3. Bathyraja spinicauda (Jensen, 1914). Spinetail skate. 9.1.4. Breviraja? sp. 1 [Stehmann, 1979] 9.1.5. Amblyraja hyperborea Collette, 1879. Arctic skate. 9.1.6. Amblyraja jenseni Bigelow & Schroeder, 1950. Jensen's skate. 9.1.7. Amblyraja radiata Donovan, 1808. Thorny skate. 9.1.8. Dipturus batis Linnaeus, 1758. Gray skate. 9.1.9. Dipturus? lintea Fries, 1838. Sailskate. 9.1.10. Dipturus nidarosiensis Collett, 1880. Norwegian skate. 9.1.11. Dipturus oxyrhynchus Linnaeus, 1758. Sharpnose skate 9.1.12. Dipturus sp. [Stehmann, 1990] 9.1.13. Leucoraja circularis Couch, 1838. Sandy skate. 9.1.14. Leucoraja fullonica Linnaeus, 1758. Shagreen skate. 9.1.15. Leucoraja melitensis Clark, 1926. Maltese skate. 9.1.16. Leucoraja naevus Müller & Henle, 1841. Cuckoo skate. 9.1.17. Leucoraja? undulata Lacepede, 1802. Undulate skate.

9.1.18. Malacoraja kreffti (Stehmann, 1978). Krefft's skate or ray. 9.1.19. Malacoraja spinacidermis (Barnard, 1923). Prickled skate. 9.1.20. Neoraja caerulea (Stehmann, 1976). Blue pygmy skate. 9.1.21. ?Raja africana Capape, 1977. African skate. 9.1.22. Raja asterias Delaroche, 1809. Atlantic starry skate. 9.1.23. Raja brachyura Lafont, 1873. Blonde skate. 9.1.24. Raja clavata Linnaeus, 1758. Thornback skate. 9.1.25. Raja microocellata Montagu, 1818. Smalleyed skate. 9.1.26. Raja miraletus Linnaeus, 1758. Twineye skate. 9.1.27. Raja montagui Fowler, 1910. Spotted skate. 9.1.28. Raja polystigma Regan, 1923. Speckled skate. 9.1.29. Raja radula Delaroche, 1809. Rough skate. 9.1.30. ?Raja rondeleti Bougis, 1959. Rondelet's skate. 9.1.31. Rajella bathyphila Holt & Byrne, 1908. Deepwater skate. 9.1.32. Rajella bigelowi Stehmann, 1978. Bigelow's skate. 9.1.33. Rajella dissimilis Hulley, 1970. Ghost skate. 9.1.34. Rajella fyllae Luetken, 1888. Round skate. 9.1.35. Rajella kukujevi Dolganov, 1985. Mid-Atlantic skate. 9.1.36. Rostroraja alba Lacepede, 1803. White skate.

10. Order MYLIOBATIFORMES (stingrays)

10.1. Family DASYATIDAE (whiptail stingrays)

10.1.1. Dasyatis centroura (Mitchill, 1815). Roughtail stingray. 10.1.2. Dasyatis chrysonota (Smith, 1828). Blue stingray. 10.1.3. Dasyatis pastinaca (Linnaeus, 1758). Common stingray. 10.1.4. ?Dasyatis tortonesei Capape, 1977. Tortonese's stingray. 10.1.5. Himantura uarnak (Forsskael, 1775). Honeycomb whipray [species complex]. 10.1.6. Pteroplatytrygon violacea (Bonaparte, 1832). Pelagic stingray. 10.1.7. Taeniura grabata (Geoffroy St. Hilaire, 1817). Round fantail stingray. 10.2. Family GYMNURIDAE (butterfly rays)

10.2.1. Gymnura altavela (Linnaeus, 1758). Spiny butterfly ray.

10.3. Family MYLIOBATIDAE (eagle rays)

10.3.1. Myliobatis aquila (Linnaeus, 1758). Common eagle ray. 10.3.2. Pteromylaeus bovinus (Geoffroy St. Hilaire, 1817). Bullray. 10.4. Family RHINOPTERIDAE (cownose rays)

10.4.1. Rhinoptera marginata (Geoffroy St. Hilaire, 1817). Lusitanian cownose ray.

10.5. Family MOBULIDAE (devil rays)

10.5.1. Mobula mobular (Bonnaterre, 1788). Giant devilray.

B. Sub-class HOLOCEPHALI (CHIMAEROIDS)

11. Order CHIMAERIFORMES (chimaeras)

11.1. Family RHINOCHIMAERIDAE (longnose chimaeras)

11.1.1. Harriotta haeckeli Karrer, 1972. Smallspine spookfish. 11.1.2. Harriotta raleighana Goode & Bean, 1895. Longnose chimaera. 11.1.3. Rhinochimaera atlantica Holt & Byrne, 1909. Spearnose chimaera. 11.2. Family CHIMAERIDAE (shortnose chimaeras)

11.2.1. Chimaera monstrosa Linnaeus, 1758. Rabbitfish. 11.2.2. Hydrolagus affinis (Capello, 1867). Atlantic chimaera. 11.2.3. Hydrolagus mirabilis (Collett, 1904). Large-eyed rabbitfish. 11.2.4. Hydrolagus pallidus Hardy & Stehmann, 1990. Pale chimaera.

The following text table provides the numbers of orders, families, genera and species of chondrichthyans in European waters (north-eastern Atlantic and Mediterranean and Black seas) with corresponding numbers for living chondrichthyans of the world.

Orders Families Genera Species

Sharks 5 (8) 20 (34) 34 (99) 69 (#470) – 15 %

Batoids 5 (5) 9 (20) 22 (69) 57 (# 650) – 9 %

Chimaeras 1 (1) 2 (3) 4 (6) 7 (#50) – 14 %

Total 11 (14) 31 ( 57) 60 (174) 133 (#1170) – 11 %

2.2. NE Atlantic (Baltic, North Sea, Western Waters, CECAF area, etc.) Historically, the value of commercial fisheries directed to elasmobranch species has ranked low in relation to other marine fisheries (Bonfil, 1994). In the Northeast Atlantic, although some elasmobranchs are taken in directed fisheries, the majority is landed as a by-catch from fisheries targeting commercial teleost species. Except for the basking shark and porbeagle, and rays in the North Sea, none of the elasmobranchs are subject to catch controls and there is no obligation for fishermen to record catches in the logbooks used for monitoring quota uptake of commercially important teleosts. Moreover, the compiled landing data on elasmobranchs are very limited due to the lack of reporting of data by species and/or by métier by most countries. Also in some countries, available landing data are highly deficient. Portugal is an example of this situation. Although there is a tradition of exploiting elasmobranchs, landing data for the beginning of the Portuguese fisheries are only reported in terms of total liver weight. These landings consist of a mixture of several species. For an analysis of these Portuguese landing data, conversion factors need to be estimated.

For the purpose of distinguishing and characterizing commercial fisheries, elasmobranchs will be divided into four groups: coastal sharks and dogfish, pelagic sharks, deep-water sharks, and skates and rays.

2.2.1. Coastal sharks and dogfish The main species in this group are the spurdog (Squalus acanthias), the lesser spotted dogfish (Scyliorhinus canicula), nursehound (Scyliorhinus stellaris) and the smooth- hounds (Mustelus spp.). Collectively, landings of this group comprise around half the total weight of elasmobranchs taken from the Northeast Atlantic.

2.2.1.1. Spurdog Spurdog is a relatively small (<130 cm TL) squaliform shark and by far the most important of the directed fisheries for elasmobranchs. This species is the most widespread of the coastal elasmobranch species in the NE Atlantic, moving in large packs, often segregated by size and sex. This behaviour might cause the high variability in catch rates in the commercial fisheries and in surveys. During the early 1900’s, spurdog was not of great economic value and landing values were small. As in other parts of the world, spurdog was viewed as a nuisance, as shoals of this species could cause considerable damage to nets in (e.g.) the herring fisheries.

The main fishing grounds for spurdog are: Norwegian Sea (ICES Sub-area II); North Sea (ICES Sub-area IV); NW Scotland (ICES Sub-area VI) and the Celtic Sea (ICES Sub-area VII) (Fig. 2.2.1). Some landings are also from the Skagerrak and Kattegat (ICES Sub-area IIIa) and Iceland (ICES Sub-area V). In the Celtic Sea, spurdog is caught primarily by French trawlers and by English and Welsh longliners. In the Bristol Channel and Irish Sea by fixed gill nets. Scottish and Irish trawlers and seiners fish for spurdog off the west coast of Scotland, and some English longliners from the east coast moved into this area after continuous poor fishing in the North Sea (Vince,

1991). They are also taken in small quantities in the Bay of Biscay (ICES Sub-area VIII) and off Greenland. These last areas are considered to be outside the main area of the NE Atlantic stock, which is also considered to be separate (at least for assessment and management purposes) from the NW Atlantic stock.

Total landings of spurdog from the NE Atlantic are difficult to determine exactly for many years since some countries combined all species of dogfish in their landings. Even so, ICES and FAO statistics indicate that spurdog landings declined rapidly from the mid-1980s. Between 1950 and 1970, Norwegian long-liners working north of Bergen, took 70% of the total international landings from the NE Atlantic; on average, half of these were taken in Norwegian coastal waters and the remainder were caught around the islands to the north of Scotland. Norwegian landings of spurdog have been sustained by the development of an extensive offshore fishery based on large vessels using long lines fishing in waters as far afield as Orkney and Shetland (Bonfil, 1994; Hjertenes, 1980), though these fisheries are seasonal and have recently become sporadic. In the 1980’s, long-line fisheries for spurdog became relatively important in the Irish Sea, with boats targeting shoals of large females. This fishery subsequently declined.

Spurdog are currently taken in mixed demersal fisheries (e.g. otter trawls) and also in gill nets, where they may be the target species. Recent catches (1997-1999) have been around 15,000 tonnes per year. The major fishing nations for spurdog are the UK, Norway, Ireland and France. Other countries (e.g. Germany, Denmark, Poland, Belgium, Spain (Basque Country, Fig. 2.2.2) and Portugal) tend to have much smaller landings (Tab. 2.2.1).

70000

60000 50000 40000

30000 20000 10000

0 1900 1920 1940 1960 1980 2000

Figure 2.2.1. Annual landings, in tonnes, of spurdog in ICES Subares II-VII.

18º 20ºW 16° 14º 12º 10° 8º 6º 4º 2°W 0° 2° E 4º 6º 8º 10°E 65º 58

63º 54

61° 50

59º 46

44 57º 42

55° 38

53º 34

32 51° CATCHES OF 30

S. acanthias 28 49º 2000 26 1-100 KG. 24

47º 100- 1000 KG. 22 1000- 10000 KG. 20 45° > 100000 KG. 18

43º 14

41° 10

39º 06

37º 02

00 C9 D1 D3 D5 D7 D9 E1 E3 E5 E7 E9 F1 F3 F5 F7 F9

Figure 2.2.2. Distribution of Basque Country (Spain) trawler fleet catches of spurdog in 2000.

Table 2.2.1. Annual landings, in tonnes, of spurdog in Portuguese ports (Portugal Mainland) and Basque Country (Spain). Sources: Database of the General Portuguese Directorate of Fisheries; AZTI Database.

Portugal Mainland Basque Country (Spain) Year IXa VI VII VIIIabd VIIIc 1986 0.9 1987 4.1 1988 1.2 1989 1.5 1990 3.9 1991 4.3 1992 1.7 1993 4.7 1994 6.7 0.0 0.0 0.1 0.0 1995 5.5 12.8 0.2 23.0 0.0 1996 2.6 6.7 4.2 43.2 0.8 1997 2.1 7.2 6.7 34.2 0.0 1998 1.6 7.3 7.3 27.2 0.0 1999 1.5 28.5 8.2 23.5 0.0 2000 2.0 21.9 18.9 38.6 0.0 2001 2.8 12.9 20.8 11.1 11.2 Total 47.2 97.2 66.3 200.9 12.0

Danish landings of spurdog (Tab. 2.2.2), with a mean annual value of 148 tonnes, are taken mainly by trawl targeting Nephrops (42 tonnes of spurdog), industrial species (20 tonnes) or monkfish (16 tonnes). The gillnet fisheries for cod or plaice have annual spurdog landings of 27 tonnes. The spatial distribution of landings follows the overall pattern for the Danish fishing fleet, with relatively larger landings, however, from Skagerrak and the deeper part of the North Sea along the Norwegian coast (Fig. 2.2.3).

Table 2.2.2. Spurdog landings by Denmark: distribution (percentage) and average annual weight landed by fishing gear and area for the period 1995-1999.

ICES area

Fishing Gear IV IIIas IIIan Other All

Fishhook 0.2 0.0 0.1 0.3 0.1

Gill net 28.2 4.1 10.7 9.6 18.4

Pair trawl 1.6 0.1 0.9 2.7 1.3

Danish Seine 8.3 0.5 3.3 1.5 5.3

Trawl 60.1 95.0 84.2 67.1 72.3

Other and unknown 1.6 0.3 0.8 18.9 2.6

All 100% 100% 100% 100% 100%

Tot. land weight

(whole fish, ton) 71 13 52 12 148

2 6

1 6

0 6 9 5 8

e 7 5 d u t

i t 6 a 5 L

5 5

4 5 3 5 2

1 5 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 Longitude

Figure 2.2.3. Danish landings of spurdog in the period 1995-1999. Surface area of the dots gives relative landings weight per ICES rectangle.

2.2.1.2. Catsharks and nursehounds Catsharks in the NE Atlantic appear to be much more sedentary than the spurdog, and the few available tagging results indicate quite restricted movement. The lesser spotted dogfish (Scyliorhinus canicula) is common on all coasts, from Mediterranean latitudes to south Norway, and contributes substantially to the landings of ‘dogfish’ from the North Sea, English Channel, Celtic Sea and Iberian waters. Data on landings of this species are not supposed to be mixed with other species. Most of the landings of dogfish in the UK are from the by-catch in towed demersal gears, usually in otter trawls and seines, mainly targeted at gadoids and flatfish, although in some coastal areas there are a few, seasonal, small-scale directed fisheries. The ‘dogfish’ landings consist principally of the spurdog and lesser spotted dogfish.

French fleets catch about 20 species of elasmobranchs, and land a greater weight of these fish. Most elasmobranch landings are taken as a by-catch and occur in all gear sectors of the commercial fleet. In 1993, trawlers landed around 85% of the elasmobranch catch, of which the most abundant species was the lesser spotted dogfish (4,445 tonnes, 21.5%). In Spain, lesser spotted dogfish is the most important shark species in the by-catch of the demersal fishery that operates along the north and northwest coast. However most of the species is discarded (only 10% is actually landed, which represents around 200 tonnes) as observed in the Spanish fishing fleets operating in the Cantabrian Sea (ICES, 2002a). In Portugal Mainland lesser spotted dogfish is mainly caught by coastal trawlers and by the artisanal fishing fleet. However most of the landings are recorded under the generic name of Scyliorhinus spp. For the period between 1989 and 2001 landings were around 600 tonnes.

The nursehound (Scyliorhinus stellaris) is found on rough, even rocky grounds to the south and west of the UK, extending to the Mediterranean. Because it is comparatively scarce it has only a minor contribution to commercial fisheries.

2.2.2. Pelagic sharks

2.2.2.1. Basking shark The geographical and temporal distribution of the Norwegian domestic basking shark (Cetorhinus maximus) fishery changes markedly from year to year, and this was suggested by Stott (1982) to be due to the unpredictable nature of the sharks' inshore migration. The Norwegian fleet has prosecuted local fisheries from the Barents Sea to the Kattegat, as well as more distant fisheries ranging across the North Sea and as far afield as the south and west of Ireland, Iceland and Faeroe.

Table 2.2.3 International basking shark catches: in numbers from 1946-1986 and in weight (tonnes) from 1985-1996.

Year Scotland Ireland Norway* Year Ireland Norway*(Achill)

1946 66 426 1971 29 1,708

1947 245 6 250 1972 62 1,438

1948 222 80 964 1973 85 2,214

1949 35 450 782 1974 33 2,148

1950 77 905 1,764 1975 38 3,670

1951 147 1,630 806 1976 1,502

1952 68 1,808 392 1977 1,586

1953 110 1,068 596 1978 1,570

1954 1,162 682 1979 2,268

1955 1,708 294 1980 1,606

1956 977 528 1981 776

1957 468 258 1982 930

1956 500 122 1983 758

1959 280 2,532 1984 888

1960 219 4,266 1985 631 (3156t)

1961 258 2,042 1986 493 (2465t)

1962 116 1,266 1987 352

1963 75 2,210 1988 228

1964 39 2,138 1989 1278

1965 47 1,304 1990 1932

1966 46 1,822 1991 1623

1967 41 4,180 1992 3658

1968 75 3,160 1993 2910

1969 113 3,130 1994 1762

1970 42 3,774

* Assumes a mean liver weight of 0.5 t. ** Minimum value. Up to 300 taken annually during 1947 and 1948. (Data sources: Department of Agriculture and Fisheries for Scotland (DAFS), Marine Laboratory, Aberdeen; McNally (1976); Norges Fiskeristatistikk; Norges Fiskeridirektoratet; Norges Fiskerier).

2.2.2.2. Blue shark There are no large-scale directed fisheries for blue shark (Prionace glauca) and it is mainly taken as a by-catch in fisheries for tuna and billfish. The entire catch is not retained on all fishing trips, so available landing data might not be indicative of stock trends.

In the summer months, blue sharks move north to cooler waters as far as the south coast of England and southern and western coasts of Ireland, where they are also subject to a recreational rod-and-line fishery and where a directed fishery using longlines and gillnets (which also takes spurdog and hake (Merluccius merluccius)) commenced in 1991. Since some years, there is also a small Spanish longline fishery targeting the species in the Gulf of Biscay (Tab. 2.2.4).

Table 2.2.4. Annual landings of blue shark from the directed Spanish longline fishery (Basque Country , Spain) from 1998 to 2000. Source: AZTI Database.

Ices Sub- areas VIII abd and VIII c 1998 121 1999 335 2000 343

Blue sharks are also taken as a by-catch in the offshore fisheries targeting tuna with longlines and driftnets beyond the slope of the continental shelf. Spain and Portugal, both Mainland and Azores (Tab. 2.2.5), have long-line fisheries for tuna and there is some by-catch of blue sharks. In addition, France, UK and Ireland have had gill-net fisheries for albacore tuna in which blue sharks are taken as a by-catch.

Table 2.2.5. Annual landings of blue shark and mako (Isurus oxyrinchus) in the Azores (ICES Sub-area X) caught as by-catch from coastal swordfish hisheries (1984- 2001).

Year Mako Blue shark Obs. I. Oxyrinchus P. glauca 1984 0.1 1985 0.1 1986 0.0 1987 11.5 1988 6.5 1989 0.5 1990 5.4 0.7 1991 14.2 37.1 1992 6.6 149.9 1993 5.7 139.6 1994 7.6 137.6 Mixed? 1995 11.7 256.1 Mixed? 1996 10.8 328.2 Mixed? 1997 3.8 92.3 1998 6.4 12.1 1999 9.3 9.3 Mixed? 2000 18.2 Mixed? 2001 22.4 Mixed?

However, the most important source of mortality on blue sharks probably arises where they are taken as a by-catch in the longline and driftnet fleets, targeting tuna and billfish, particularly from nations with high seas fleets such as Japan, Taiwan, Korea and Russia. Because there is usually no requirement for these fisheries to record their blue shark catch, its magnitude (and the consequent mortality) is not reflected in catch statistics. Due to the increasing price paid for shark fins, however, the difference between target and by-catch species in these fisheries is becoming less clear.

2.2.2.3. Porbeagle and tope Porbeagle (Lamna nasus) and tope (Galeorhinus galeus) are other pelagic species that have been the target of both recreational and commercial fishing.

The porbeagle shark is one of the most biologically vulnerable to over-exploitation of all European shark species. It reaches a maximum fork length (FL) of 320 cm and lives to an age of 30-40 years. Males mature at about 174 cm FL (8 years old) and females at about 217 cm FL (around 13 years old). Litter size averages four relatively large pups (60-70 cm) after a gestation period of 8-9 months. Mature females in the northwest Atlantic stock appear to reproduce annually (many other large sharks have a one-year resting period following parturition, bearing litters at two-year intervals).

The porbeagle is taken in much lower numbers than the blue shark, and is subject to different fisheries along its migratory route. Traditional fisheries for porbeagle in the northern North Sea have operated out of Norway, Denmark and to a lesser extent the UK. About 6,000t were taken by the Norwegian fleet in 1947, when the fishery reopened after World War II. A progressive drop in northeast Atlantic landings followed from 1953-1960, to around 1,200-1,900 t annually. ICES data (ICES 1995) track the continued decrease in Norwegian landings from the Northeast Atlantic from 160-300 t/annum in the early 1970s to around 10-40 t/annum in the late 1980s/early 1990s. Gauld (1989) describes the declining Danish porbeagle fishery from average landings of 500-600 t/annum in the 1950s to under 50 t in 1984. ICES (1995) present more recent data from Denmark; a minimum of 32 t landed in 1988, rising to 94 t in 1994.

Bonfil (1994) estimates that 50 t of porbeagles were taken in the Spanish longline swordfish fishery in the Mediterranean and Atlantic during 1989. The porbeagle is also caught by French longliners in the Celtic Sea and Bay of Biscay, from where over 77% of the total French catch recorded by all gears in 1993, was 640 tonnes. In Portugal Mainland the total landings attained nearly 80 tonnes in 2001.

There is no directed commercial fishery for tope in European waters (though some recreational anglers specialize in tope catching). Tope is mainly taken as a by-catch in bottom trawl, net and line fisheries of all countries bordering the NE Atlantic, and especially by French vessels fishing in the English Channel, Western Approaches and northern Bay of Biscay (Bonfil, 1994). According to French catch statistics for 1987,

it ranked third (at about 600 tonnes, some 6% of the total) in shark catches behind spurdog and lesser spotted dogfish. Tope also feature in catch statistics for Portugal Mainland and in the Azores. In Azores this species is a by-catch from the demersal longline fishery. Total landings have increased from 23 tonnes during the 1980s to 142 tonnes in 2000.

2.2.3. Deep-water sharks Deep-water sharks, taken either by mixed or by directed fisheries, will be briefly described by ICES Subareas. Despite some effort already initiated towards the discrimination of landings at species level, this goal is not effectively attained yet. Table 2.2.6a presents landings of sharks not elsewhere identified, containing an unknown component of deepwater sharks, as reported to ICES. Table 2.2.6b present landings of small squalid sharks, as reported to ICES.

Table 2.2.6a. Landings of sharks, not elsewhere identified, containing an unknown component of deepwater sharks, as reported to ICES.

IVa Va Vb Via VIb VII VI+VII VIII + IX XII Total 1990 3 0 43 0 46 1991 0 133 3 254 2850 3240 1992 0 51 41 639 3740 4471 1993 0 86 387 1392 0 1865 1994 0 10 43 1864 4 1921 1995 0 6 0 2099 39 2144 1996 0 32 2176 25 2233 1997 0 47 3240 1079 4366 1998 0 20 0 3023 1811 4854 1999 53 0 9 136 112 244 1791 476 2821 2000 10 0 69 145 420 164 8 228 38 1082 2001 10 212 68 210 315 0 321 1136 73 306 843 349 742 723 16486 10573 38 30133

Table 2.2.6b. Landings of small squalid sharks, as reported to ICES. Landings in IVa are Etmopterus spinax. In other areas they include Etmopterus princeps, Centroscyllium fabricii, Centroscymnus crepidater and possibly Deania calcea.

IVa VIa VIb VII XII Total 1991 0 1992 0 1993 27 27 1994 0 0 1995 10 10 1996 8 8 1997 32 32 1998 359 359 1999 128 128 2000 26 127 2 4 222 381 2001 52 120 25 6 483 686 642 247 27 10 705 1631

Sub-areas I, II, III and IV

There have been no reported landings of sharks in Sub-areas I and II since 1990 (Anon., 2000) and those data almost certainly referred to Greenland shark (Somniosus microcephalus). Landings data for velvet belly (Etmopterus spinax) in Division IVa rose to over 350 t in 1998, but declined to 52 tonnes in 2001. Landings of deepwater sharks (almost exclusively leafscale gulper shark (Centrophorus squamosus) and Portuguese dogfish (Centroscymnus coelolepis)) by France, UK (England and Wales) and UK (Scotland) probably refer to fisheries west of the Shetland Isles. English/Welsh and Scottish landings have been small in most years, and French landings have declined from a maximum of just over 130 t in 1992.

Sub-areas V, VI and VII

Landings of Greenland shark by Iceland in Division Va have fluctuated between 30 and 82 tonnes since 1989 (Tab. 2.2.7). Whilst Portuguese dogfish occurs in this area, landings are infrequent. In Division Vb France has had the largest landings, fluctuating around 200 to 300 tonnes in most years, though reaching a peak of 460 tonnes in 1999. There have been some catches of Portuguese dogfish, and in 2001 also of leafscale gulper shark, by the Faeroe Islands. UK (England and Wales) and UK (Scotland) have begun to collect separate landings data for deepwater sharks (almost exclusively leafscale gulper shark and Portuguese dogfish) since 1999, but it is not possible to ascertain what proportion of earlier landings for these countries, or for Germany, were deepwater sharks.

Table 2.2.7. Landings of Somniosus microcephalus in Division Va.

Va 1988 1989 31 1990 54 1991 58 1992 70 1993 39 1994 42 1995 45 1996 65 1997 70 1998 82 1999 45 2000 45 2001 56

Two species of sharks are routinely landed for their flesh and livers in VI and VII; the leafscale gulper shark and the Portuguese dogfish. These species are collectively called “siki” in French fishery records (Gordon, 1999), though they are marketed elsewhere under this name too. French vessels catch these species in the mixed-

species bottom trawl fishery, and landings have increased from 302 tonnes in 1991 to 3,284 tonnes in 1996, declining to 1,939 t in 1999 (ICES, 2000), see Table 2.2.8.

Spanish longliners target deepwater sharks too (Pineiro et al., 2001) but it is difficult to quantify landings as separate statistics for deepwater sharks are not collected by species for these vessels. More recently, longliners from Norway and trawlers and longliners from Scotland and Ireland are catching these species. Other, smaller species of deepwater sharks are now being landed, or in some cases livers or fins are retained and the carcasses discarded. These species are black dogfish (Centroscyllium fabricii), birdbeak dogfish (Deania calcea) and long-nose velvet dogfish (Centroscymnus crepidater). Apart from France no other country reports landings data for deepwater sharks separately, but rather for shelf and slope species combined. In this area, deepwater sharks are also taken by gill-netters, but there are no data available.

Table 2.2.8. Landings of Centrophorus squamosus and Centroscymnus coelolepis as reported to ICES, by Sub-area or Division.

IVa Va Vb VIa VIb VI VII VI / VII VIII IXa X XII Total 1990 140 475 615 1991 3 75 944 265 1075 1 2363 1992 133 123 1953 878 15 1114 2 4218 1993 51 91 2454 857 9 946 6 4414 1994 86 149 2198 1363 8 1155 8 4967 1995 10 262 1784 991 0 1354 139 4540 1996 6 348 2374 754 1 1189 147 4819 1997 261 2222 571 1 1311 32 4398 1998 5 433 2081 673 13 1220 4 56 4485 1999 20 461 1651 472 440 20 972 8 50 4094 2000 0 340 2570 470 621 21 1049 809 5880 2001 0 331 2986 801 1032 5 1130 725 7010 309 5 3014 7207 1743 16010 8445 93 12990 12 1975 51803

Sub-area VIII

There have been Spanish, French, English/Welsh and Scottish landings of sharks in Sub-area VIII, but the deepwater component is unknown. There are directed longline fisheries in this area for sharks. The main species are leafscale gulper shark and Portuguese dogfish, as in the northern areas, but also gulper shark (Centrophorus granulosus) and kitefin shark (Dalatias licha). Some of the smaller sharks, such as long-nose velvet dogfish, great lanternshark (Etmopterus princeps), and birdbeak dogfish, are sometimes taken (Pineiro et al. 2001).

Sub-area IX

At Sesimbra (ICES Subdivision IXa) the longline fishery targeting black scabbardfish has other deep-water species as by-catch, and these provide an important additional income. The most important species are the Portuguese dogfish and leafscale gulper sharks (Tab. 2.2.9), however, other species such as kitefin shark, birdbeak dogfish, gulper shark and knifetooth dogfish (Scymnodon ringens) are also caught.

Table 2.2.9. Annual landings (in tonnes) of Portuguese dogfish and leafscale gulper shark from the Sesimbra longline fishery (1991 - 1998).

Year Portuguese dogfish Leafscale gulper shark 1991 586 287 1992 577 372 1993 485 281 1994 530 531 1995 763 512 1996 741 380 1997 866 370 1998 812 331

Source: General Portuguese Directorate of Fisheries Database.

Deep-water sharks are also caught by the Portuguese deep-water bottom trawl fishery that targets the rose shrimp (Parapenaeus longirostris) and Nephrops. This fishery takes mainly place south and southwest off Portugal Mainland. Deep-water shark species caught in this fishery are: birdbeak dogfish, blackmouth catshark (Galeus melastomus), gulper shark, kitefin shark (Tab. 2.2.10), leafscale gulper shark, smooth lanternshark (Etmopterus pusillus) and velvet belly (Etmopterus spinax).

At Portugal Mainland a directed longline fishery for deep-water sharks, is based at Viana do Castelo, a northern Portuguese town located near the border with Spain. It was initiated in 1983 and the landings in this fishery are predominantly of gulper shark. However, other deep-water species are caught in relatively small quantities. These include the leafscale gulper shark, Portuguese dogfish, blackspot seabream (Pagellus bogaraveo), greater fork-beard (Phycis blennoides), European conger (Conger conger) and the black scabbardfish. In the early years of the fishery only the livers of the sharks were of commercial value. Livers were removed on board and stored in barrels and the carcasses were discarded at sea. Although livers continue to have some economic importance, nowadays to increase the value of the fish, fishermen process part of the catch on board. Gutted, headed and skinned gulper sharks are sold. In more recent years only one longliner is fishing full time (Tab. 2.2.10). The decrease in the level of fishing activity is closely associated with two main factors: foreign competition and market fluctuations in the price of oil that is extracted from the livers.

Table 2.2.10. Annual landings (in tonnes) of gulper shark, Portuguese dogfish and leafscale gulper shark from the Viana do Castelo longline fishery.

1991 1992 1993 1994 1995 1996 1997 1998 Gulper shark 499.5 715.2 710.1 186.3 252.7 103.3 90.0 21.2 Portuguese dogfish 42.7 98.0 95.2 29.5 31.1 20.4 42.0 23.7 Leafscale gulper shark 0.6 1.8 0.1 2.8 0.3 1.0 * 13.1

Source: General Portuguese Directorate of Fisheries Database.

Sub-area X

In the Azores, deep-water sharks are caught as by-catch both from the demersal and black scabbardfish fisheries but the landing data are not collected by species. The deep-water shark species caught by these fisheries and identified from demersal surveys are: Deania profundorum, birdbeak dogfish, leafscale gulper shark, gulper shark, velvet belly, smooth lanternshark (Etmopterus pusilus), great lanternshark, kitefin shark, Squaliolus laticaudus, Centroscysmnus crepidater, Centroscymnus cryptacanthus, Portuguese dogfish, little sleeper shark (Somniosus rostratus), Heptranchias perlo and Galeus marinus.

In the Azores there is also a directed fishery for kitefin shark (Tab. 2.2.11), which has been in existence for over 20 years. This fishery uses both gillnets and handlines, the first of which tend to catch mostly males and the other mostly females. The landings peaked at 950 tonnes in 1981 and have decreased to 40 tonnes in 1998. The last boat operated until 1998, after which the fishery was considered extinct. Presently, a few small open-deck boats have returned to the traditional handlines to fish for kitefin shark, with landings of about 30 tonnes in 1999 and 2000 (Tab. 2.2.12). Catch rates are apparently high, and several other cabin-deck boats seem to be motivated by these results, and a shift from demersal fishery to kitefin fishery is being considered.

Table 2.2.11. Landings of Dalatias licha in Division IXa and X as reported to ICES.

IXa X TOTAL 1988 149 549 698 1989 57 560 617 1990 7 602 609 1991 12 896 908 1992 11 761 772 1993 11 591 602 1994 11 309 320 1995 7 321 328 1996 4 216 220 1997 4 30 34 1998 6 34 40 1999 6 31 37 2000 31 31 2001 7 13 20 292 4944 5236

Sub-area XII

In Sub-area XII there have been some French landings of deepwater sharks, but it is not possible to detect any trends from these data.

2.2.4. Skates and rays In addition to the fisheries mentioned above, there are a number of small fisheries targeting various species of Rajidae in relatively limited geographical areas. Fishing methods include longlines set for species such as the common skate and, more

recently, large meshed fixed gill nets have been set to catch thornback and spotted rays in coastal areas. However, directed fisheries for rays have been few and small in scale compared with those for spurdog.

France, Ireland and the UK have traditionally had some directed fisheries for rays and collectively landed the largest proportion of the catch. Most of the French catches of rays come from the Celtic Sea and English Channel, though they are taken mainly as a by-catch during bottom trawling. The cuckoo ray has contributed over 30% of the total French ray catch in recent years, and comes mainly from the southern part of the Celtic Sea and the northern part of the Bay of Biscay. The thornback ray (Raja clavata) is often the target of directed seasonal fisheries by France, which takes most of the catch of this species from the Celtic Sea and Irish Sea.

Table 2.2.12. Annual landings (in tonnes) from the Azorean Kitefin shark fishery by fleet component. Total landings can exceed the sum of both components because these include by-catches for other fisheries or values from unknown sources (1972 - 2001). Landings Average Handlines Bottom gillnets Total Price/kg Year (mt) (mt) (mt) (Euro) 1972 14.7 14.7 0.02 1973 22.3 22.3 0.01 1974 161.4 161.4 0.02 1975 97.4 97.4 0.02 1976 11.8 11.8 0.02 1977 153.9 188.0 0.03 1978 196.4 196.4 0.04 1979 232.7 232.7 0.08 1980 226.5 396.1 658.4 0.13 1981 173.7 667.2 947.0 0.15 1982 59.6 81.9 141.6 0.13 1983 90.9 83.4 220.3 0.34 1984 95.2 842.0 937.4 0.40 1985 73.8 814.4 902.5 0.32 1986 63.5 663.0 741.0 0.39 1987 117.9 290.3 413.2 0.30 1988 62.6 443.3 548.9 0.34 1989 105.8 452.1 559.8 0.36 1990 100.9 492.0 601.8 0.40 1991 87.6 793.9 896.3 0.49 1992 64.3 672.2 760.8 0.79 1993 40.9 550.4 591.3 0.51 1994 49.8 258.7 309.0 0.56 1995 51.1 269.4 320.9 0.39 1996 68.4 147.7 216.4 0.50 1997 29.9 121.8 151.9 0.52 1998 29.9 6.3 40.4 0.58 1999 23.6 31.3 0.40 2000 22.8 0.1 31.0 0.33 2001 10.6 0.9 12.7 0.35 Sources: DOP data base and Lotaçor Empty spaces = Catches not reported. Gillnets data from 1997 and 1998 was estimated from logbooks.

Trawlers operating out of Milford Haven in the 1950s and 1960s targeted rays, especially thornback rays off the south east coast of Ireland. This fishery is still continued on a smaller scale by vessels from the Irish Republic. During the last decade, small-scale fixed-net fisheries targeting thornback ray have developed off the west and north coasts of Wales, and similar fisheries using lines, fixed nets and trawls have taken place in localized coastal regions in the North Sea. Total international landings of all rays combined from the North Sea, have steeply declined since World War II (Fig. 2.2.4).

In recent years rays and skates (Rajidae) have contributed more than 40% by weight to the reported landings of elasmobranchs at the Northeast Atlantic. Despite their high importance, statistical information by species is limited, as most European countries do not differentiate between species in landing statistics and they are collectively recorded as skates and/or rays (Tab. 2.2.13 to 2.2.18).

20000

15000

s e

n 10000 n o

5000

0 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000

Figure 2.2.4. International landings of Rays and Skates from the North Sea (Source: Bulletin Stat ICES).

Table 2.2.13. Landings data of rays and skates, collectively recorded as Raja spp. Distribution (percentage) and average annual weight of Danish landings by fishing gear and ICES Sub-area (1995-1999).

ICES area Gear IV IIIas IIIan Other All Beam trawl 0.0 - 0.1 0.0 0.0 Gill net 9.0 53.3 0.7 0.1 5.9 Pair trawl 0.7 0.0 0.4 0.3 0.5 Danish seine 1.0 7.7 0.6 0.0 0.9 Trawl 87.5 38.0 97.5 94.8 90.7 Other and unknown 1.7 1.0 0.7 4.8 1.9 All 100 100 100 100 100 % % % % % Tot. land weight (landed weight, ton) 16 2 14 8 40

Table 2.2.14. Landing data of rays in live weight, in tonnes, as reported by Ireland to STATLANT.

Area 1973 1974 1975 1976 1977 1978 1979 1980 VIa 281 336 458 425 342 242 268 343 VIb . . . . . 0 . . VII 266 321 314 320 265 268 239 269 VIIa 822 916 838 936 858 796 813 725 VIIg 147 158 148 241 158 143 218 397 VIIj ...... VIIk 1981 1982 1983 1984 1985 1986 1987 1988 VIa 474 537 806 836 574 440 367 690 VIb ...... VII 336 271 325 296 220 226 . . VIIa 851 803 781 1,067 1,946 1,416 1,644 1,911 VIIb ...... 419 332 VIIg 380 291 236 303 286 251 29 57 VIIj ...... 267 258 VIIk 1989 1990 1991 1992 1993 1994 VIa 630 150 200 350 331 265 VIb . . . . 24 23 VIIa 1,808 1,811 1,400 1,301 679 514 VIIb 305 200 200 300 355 342 VIIc 1 9 VIIe ...... VIIh 5 4 VIIg 57 100 68 . 114 93 VIIj 328 150 200 319 246 274 VIIk

Table 2.2.15. Preliminary Irish landings (live weight tonnes) for skates and rays, by ICES Division, from EU logbook scheme.

ICES Sub-area 1995 1996 1997 1998 1999 2000 2001 IVa 0 VIa 467 610 530 414 340 271 222 VIb 63 68 25 16 29 18 10 VIIa 430 438 593 692 827 759 807 VIIb 335 313 369 361 384 340 338 VIIc 15 7 12 1 7 33 36 VIIe 1 3 1 1 0 1 0 VIIf 0 0 1 0 0 0 VIIg 76 200 196 206 198 196 265 VIIh 8 16 9 6 6 12 3 VIIj 61 127 262 221 195 207 175 VIIk 3 0 1 9 2 35 11 XII 1 TOTAL 1469 1782 1997 1930 1988 1871 1868

Table 2.2.16. Annual landings, in tonnes, of Raja spp by ICES Sub-area from Basque Country (Spain) between 1994-2001.

ICES Subarea Year VI VII VIIIabd VIIIc 1994 0.9 66.9 198.7 0.1 1995 1.2 145.4 519.8 0.1 1996 1.6 176.6 500.2 14.6 1997 3.4 70.0 586.7 10.8 1998 5.1 108.7 620.6 10.8 1999 8.8 92.4 386.4 13.1 2000 8.3 88.6 296.9 5.1 2001 28.1 42.8 314.2 10.3 Total 57.4 791.4 3423.3 64.7

Table 2.2.17. Annual landings, in tonnes, of Raja spp from different segments of the Portuguese fishing fleet (ICES Subarea IXa) between 1986-2001.

Year Trawl Artisanal Purse-seine Port/Spain Total global 1986 539 1150 4 1693 1987 552 2131 7 4 2694 1988 536 1551 6 10 2103 1989 500 1217 6 8 1731 1990 490 1029 6 8 1533 1991 382 982 8 4 1375 1992 343 1202 5 4 1553 1993 363 1239 6 5 1613 1994 346 1007 5 11 1369 1995 358 1062 5 8 1433 1996 402 1119 3 9 1534 1997 398 1106 3 5 1512 1998 354 1119 3 9 1485 1999 293 21621 3 4 21921 2000 314 1207 4 3 1528 2001 354 1226 5 4 1589 Total global 6523 39968 77 98

Table 2.2.18. Commercial landings (mt) of Raja spp., reported for the Azores (ICES Sub-area X), 1975-1998.

TOTAL Mean price TOTAL Mean price Landings per kg (Euro) Landings per kg (Euro) 1975 37.9 0.02 1989 28.8 0.18 1976 - - 1990 34.5 0.15 1977 - - 1991 51.5 0.22 1978 56.5 0.07 1992 42.6 0.19 1979 83.3 0.07 1993 31.8 0.20 1980 86.1 0.08 1994 55.0 0.29 1981 74.0 0.11 1995 61.6 0.26 1982 45.6 0.10 1996 70.8 0.32 1983 43.6 0.10 1997 99.0 0.32 1984 37.8 0.13 1998 117.0 0.37 1985 24.7 0.13 1999 102.6 0.51 1986 27.4 0.17 2000 83.0 0.63 1987 37.3 0.20 2001 68.0 0.55 1988 47.8 0.19

2.3. Mediterranean The production of elasmobranchs in the Mediterranean Sea is relatively low. In 1999 the total production was 11265 tonnes. The following figure shows the evolution of the production during the last thirty years.

Mediterranean and Black Sea trend of catches in the last 30 years (FAO data, FISHSTAT 2000)

30000

25000

s 20000 n o t

i 15000 r t e

M 10000

5000

0 1970 1975 1980 1985 1990 1995 2000

In the period 1970-1985 an increase can be seen from 10000 to 25000 metric tons and a slow decrease to 15000 in the following 15 years. At present the major fishing countries are the following: Turkey (2115 tons), Tunisia (2018 tons), Greece (1602 tons), Italy (1557 tons) and Spain (1466 tons).

Minor quantities of elasmobranch landings are reported for other Mediterranean countries such as France (63 tons). No data are available for some European Mediterranean countries (Croatia, Slovenia, Albania).

Until 1998, Italy was the main fishing country for the Mediterranean elasmobranch production with a maximum of 12357 tonnes in 1994, following by a fast and strong decrease as the Italian production fell down to 1557 tonnes in 1999. The most important European fishing countries, Spain and France do not report substantial catches of elasmobranchs from the Mediterranean Sea.

On average this production represents 1.1% of the total landings in Mediterranean harbours. The most important areas for elasmobranch catches are the Ionian and Black Seas each one with 30% of the total Mediterranean catches; Sardinian, Adriatic and Balearic waters show catches of 12%, 8% and 7% respectively of the Mediterranean total. The main commercial categories of cartilaginous fishes by importance in the landings are shown in Table 2.3.1.

Table 2.3.1. Mediterranean and Black Sea elasmobranch landings in 1998 (FAO data)

Commercial categories Taxonomic categories Landings (in tons)

Rays, Stingrays, Mantas Rajiformes 5326

Sharks, Rays, Skates Elasmobranchii 4073

Smooth-hounds nei Mustelus spp. 2628

Dogfish sharks nei Squalidae 947

Raja rays nei Raja spp. 445

Dogfish sharks etc. nei Squaliformes 289

Anneigelshark Squatina spp. 171

Piked dogfish Squalus acanthias 97

Guitarfishes nei Rhinobatos spp. 93

Angelshark Squatina squatina 44

Thornback ray Raja clavata 29

Basking shark Cetorhinus maximus 6

Blue shark Prionace glauca -

Shortfin mako shark Isurus oxyrinchus -

Porbeagle Lamna nasus -

Total 14148

Among the sharks the smooth-hounds (Mustelus spp.) were the most important group, with catches of 2628 tonnes, then the dogfishes with 1333 tonnes. Among the skates, only the thornback ray has separate data. Some species reported in previous years are not reported in 1998 (e.g. the blue shark, the shortfin mako and the porbeagle), this may be due to lack of transmission of data to FAO by some Mediterranean countries).

Only few cartilaginous species constitute the target of Mediterranean fisheries. Most local Mediterranean fisheries do not target any particular group of elasmobranch species, which are taken as by-catch.

Elasmobranchs are caught by different gears, adapted to fish in different habitats. The following fisheries will be described: coastal, pelagic and deep-sea fisheries.

2.3.1. Coastal fisheries On the continental shelf, elasmobranchs are usually caught by bottom trawl, trammel, gill nets and longlines, as a by-catch in fisheries targeted to other species, generally bony fishes (hake, red mullet, sparids), crustaceans (mainly coastal Penaeids, mantis shrimp) or molluscs (octopuses, squids, cuttlefish).

The most common elasmobranchs, in order of importance for the coastal fisheries, are: Mustelus spp., Rajids, Scyliorhinus spp., Squalus sp., Myliobatids and Dasyatids.

In the fisheries using bottom trawls, some species of rays are of secondary importance or, sometimes, they are the most important component of the fishery. The "rapido" (a variant of beam trawl) fishery in the North Tyrrhenian, South-East Ligurian and Adriatic Seas, should not be economically sustainable if R. asterias, or other low priced species were discarded. Rays are generally predominant in weight in the daily catch with the "rapido" in the north Tyrrhenian Sea. The relatively high abundance of the stocks of R. asterias, a coastal species present on grounds exploited with relatively high rates, is a rare exception. Its resistance to high fishing pressure can probably be explained by the particular characteristics of their natural history such as a relatively high fecundity.

Bottom trawl nets may remove significant quantities of egg capsules of different elasmobranch species, especially when fishing activity occurs near the Posidonia beds or other organisms like yellow gorgonians, where the eggs are fixed.

In the fisheries using trammel and gill nets the elasmobranch catches can locally be high; for example the skate Raja brachyura in the trammel fishery along the North- western Sardinian coasts (Vacchi, unpublished data). In the same way, the basking shark (Cetorhinus maximus) is incidentally caught with trammel and gill nets in the Ligurian and Tyrrhenian Sea (Serena & Vacchi, 1997). These incidental catches are reported mainly during spring when higher concentrations of zooplankton occur. Most of the catches consist of young individuals but adolescents and adults are also present. In the Northern Adriatic Sea, gillnets have traditionally been utilised for the catch of Mustelus mustelus, M. punctulatus, Squalus acanthias, Scyliorhinus stellaris, Myliobatis aquila and Galeorhinus galeus, Pteromylaeus bovinus (Costantini et al., 2000).

2.3.2. Deep-sea fisheries In the Mediterranean deep-sea trawl fishery exploiting red-shrimp (Aristeus antennatus and Aristaeomorpha foliacea) several shark species represent a common component of by-catch. An European Union research program (EC FAIR Rep. (95- 655) 1996) furnishes a list of the more frequent sharks species caught off the southern Balearic islands on the border of the continental shelf: G. melastomus is the most frequent species, followed by S. canicula, Centrophorus uyato, Centroscymnus coelolepis, Dalatias licha, Etmopterus spinax, Squalus blainvillei, species quite commonly caught. Many of these species have no commercial value and are systematically discarded at sea.

Similar species composition, sorting and discarding procedures as in the Balearic area characterise the deep-sea fisheries in the Northwest Ionian Sea (Univ. Bari EC FAIR deep fisheries Project 1996).

G. melastomus is the most frequent species caught. S. canicula, D. licha, and E. spinax are also part of the by-catch. Only G. melastomus and S. canicula have some commercial value while the other species are discarded. From a different study in the same area (EC-FAIR 1997), S. blainvillei appears to be the most frequent species followed by G. melastomus, S. canicula, E. spinax and D. licha.

Along the slope of the continental shelf of Greece (EC FAIR Project 95-655) E. spinax is one of the most important elasmobranchs in the by-catch of shrimp fisheries and is common in the North Aegean and the Thracian Sea, but not in the Ionian Sea. S. canicula and S. blainvillei are other quite common components of the by-catch.

According to a sampling programme of deep-sea fisheries in the Eastern Mediterranean Centrophorus squamosus, G. melastomus, Somniosus rostratus, E. spinax and H. griseus are the most important elasmobranch by-catch species. In the red shrimp fishery of the Ligurian Sea the main by-catch species is blackmouth catshark, Galeus melastomus, which is mostly discarded.

In the same way Chimaera monstrosa, G. melastomus and E. spinax caught in the Nephrops fishery in the North Tyrrhenian Sea are discarded.

In the area of Majorca, Spain, many species of small sharks are caught in deep-water crustacean fisheries but only individuals of Squalus spp., S. canicula, G. melastomus, and Centrophorus granulosus are landed (EC FAIR 1996).

Dipturus oxyrhinchus was commonly caught in the Central Ligurian Sea and in other Italian areas, but is extremely rare today. R. oxyrhinchus is a big-sized slow growing species and it is one of the species that show a clear decline due to increased fishing pressure.

2.3.3. Pelagic fisheries There are no Mediterranean pelagic fisheries targeting migratory oceanic sharks, but these species constitute a large component of the by-catch in the coastal and offshore tuna and swordfish fisheries that utilise longlines, drift-nets and purse seines.

Although located along the shoreline, fixed tuna traps also catch pelagic species. These structures were distributed all along the Mediterranean coasts, mainly in Italy. About twenty tuna traps were active in the Mediterranean up to thirty-forty years ago, but today their number has decreased and they are now confined to the major Italian islands and North Africa. In the past, numerous large pelagic sharks and other elasmobranchs were caught in tuna traps in the Mediterranean .

Today almost all Mediterranean tuna traps are closed because they are no longer remunerative. The historical data from tuna traps are very important and constitute an accurate documentation of the former greater abundance of cartilaginous fish species. Moreover, the tuna trap data show the progressive decrease in elasmobranch biodiversity. The main elasmobranch species that were traditionally caught as a tuna by-catch in the traps were big-sized individuals of thresher (Alopias vulpinus), basking (Cetorhinus maximus), blue (Prionace glauca) and white shark (Carcharodon carcharias) and, sometimes, hammerhead sharks (Sphyrna spp.) and devil rays (Mobula mobular) (Fleming & Papageorgiou, 1997; Muñoz-Chàpuli, 1994; Kabasakal, 1998; Hemida, 1998; De Metrio et al., 1999; Garibaldi & Relini, 1999).

With the moratoria of drift nets in the Mediterranean, starting in January 2002, it is expected that the undesired fishing mortality of elasmobranchs caught with this gear will be reduced. However, the mentioned species are not “covered” under any international nor national conservation plan. Until now, there are no statistical data on the by-catch of sharks in the Mediterranean pelagic fisheries. In spite of this, in some cases there are clear examples of elasmobranch species affected by pelagic gears. The violet stingray (Pteroplatytrygon violacea) is a species commonly caught in the Ligurian Sea as by-catch in the swordfish fishery and in the south-western Mediterranean. Although P. violacea in the Western Ligurian Sea represents the most important catch of the longline fishery targeted to swordfish, all specimens are discarded at sea because of the low commercial value.

Modest catches of P. glauca have been landed as a by-catch of the swordfish and albacore fisheries with drift longlines. Depending on hook selectivity and seasonal cycles, swordfish fisheries land blue sharks that are greater (mean weight 25 kg) than albacore (3 kg).

P. glauca is also caught by offshore pelagic fisheries along the Algerian coasts. Important catches of carcharhinids species (C. brachyurus, C. brevipinna, C. falciformis, C. obscurus, C. plumbeus and C. altimus) are made in the pelagic longline fishery operating from ports in eastern Algeria.

Information on by-catch and discards composed of large pelagic sharks as basking shark, white shark, thresher shark and blue shark were reported for different drift net fisheries off the Southern Italian maritime sectors and Ligurian Sea.

Despite the lack of records on elasmobranch by-catches in the pelagic fisheries, some studies have been carried out, such as a programme financed by the European Community (project N° 97/50 DG XIV/C1), which provide CPUE for large pelagic sharks as summarized in Table 2.3.2.

2.3.4. Recreational fisheries Game fishing, even if limited to some restricted areas of the Mediterranean, should not be neglected since the number of anglers is increasing. This activity is mainly conducted in the Italian part of the Adriatic Sea, but also in the Tyrrhenian Sea and along the Spanish and French coasts.

The target species of game fishing are mainly the thresher (A. vulpinus) and the blue shark (P. glauca). Catches are mainly composed of young individuals, sometimes new-born specimens. At the moment there is a lack of enforced measures for the protection of juveniles and gravid females of most elasmobranch species. It should be pointed out that anglers, more and more, release their catch after capture.

Table 2.3.2 CPUE of large pelagic sharks in the Mediterranean.

CPUE Blue shark - Prionace glauca

Period :1998-1999 Sword Sword America America Bluefin Albacor Albacor Drift net Drift net Sword Sword tuna long line long line on board fish fish long line at at Ref.:97/50 DG XIV/C1 fish fish on board landing landing long line long line on board long line long line on board at landing on board at landing

Number / 1000 hooks Number / 1000 m

Spain Alboran Sea 0,304 4,061 0,000 Spain Balearic Sea 0,027 0,087 0,287 Spain Catalonian Sea 0,299 0,310 0 ;070 Italy Adriatic Sea 1,678 0,936 0,000 Italy N. Ionian Sea 0,859 0,469 0,168 0,075 0,023 0,034 Italy Tyrrhenian Sea 0,270 Italy Strait of Sicily 0,065 0 ,000 0,000 Greece S. Ionian Sea 0,320 0,210 Greece Levantine basin 0,000 0,280 0,469 Greece Aegean Sea 1,209 0,361 0,076

Mako shark - Isurus oxyrinchus

Number / 1000 hooks Number / 1000 m

Spain Alboran Sea 0,092 0,204 Spain Balearic Sea 0,029 0,038 0,001 Spain Catalonian Sea 0,023 0,004 0,010 Italy Adriatic Sea 0,000 0,000 0,000 Italy N. Ionian Sea 0,000 0,000 0,000 Italy Tyrrhenian Sea 0,000 Italy Strait of Sicily 0,000 0,000 Greece S. Ionian Sea 0,000 0,000 Greece Levantine basin 0,000 0,280 0,087 Greece Aegean Sea 0,000 0,021

2.4. European elasmobranch fisheries outside EU waters There are no European fleets targeting elasmobranchs outside Community waters, but some European countries (Spain, France and Portugal) have important fisheries of billfish and tuna in tropical waters. By-catches of pelagic sharks in these fisheries are recordedbyn ICCAT, but not all European countries provide ICCAT with this information.

According to ICCAT, the by-catch of elasmobranchs in the Spanish swordfish fishery in ICCAT areas 94, 94A, 94B, 95, 96, 97 in 1999 was more than 29,000 tonnes of blue sharks (Prionace glauca) and 4-5,000 tonnes of other pelagic sharks (Table 2.4.1).

The Portuguese long-line fishery for swordfish in the North Atlantic started in 1985, while the fishery in the South Atlantic area gained importance in 1989. Although the blue shark and short-fin mako are considered as by-catch of this fishery the landings reported for these species are more important than the registered landings of swordfish. In the North Atlantic the catch rates of swordfish and sharks show a pronounced seasonal trend. In this area, the highest catch levels of blue sharks are obtained during the first semester. A provisional reconstruction of the historic pelagic shark landings in both areas is shown in Figures 2.4.1 and 2.4.2.. In the ICCAT data base no data are available for elasmobranch by-catches of the French fleet fishing in tropical waters.

Table 2.4.1. Catches of pelagic sharks by the Spanish swordfish fishery.

Blue shark Other pelagic sharks (*) rweight (ton) year rweight (ton)

1997 5,427 5,051,

1998 28,137 4,636

1999 29,005 3,694

(*) Basking shark, bigeye thresher, bignose shark, dusky shark, great hammerhead, lanternsharks, longfin mako, night shark, oceanic whitetip shark, porbeagle, sandbar shark, scalloped hammerhead, shortfin mako, silky shark, smooth hammerhead, thresher sharks, tiger shark, tope shark.

swordfish 6000 blue shark 5000 short-fin mako

)

T 4000 M

(

h 3000 c

t a 2000 C 1000

0 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000

Fig 2.4.1. Provisional reconstruction of historic annual landings (MT) by Portugal of swordfish and estimates of catches of blue shark and short-fin mako in the North Atlantic (ICCAT area 94B), between 1990 and 2000 (dos Santos et al. 2002).

swordfish blue shark

1000 short-fin mako

800

) T 600 M (

h c

t 400 a C 200

0 1995 1996 1997 1998 1999 2000

Fig 2.4.2. Provisional reconstruction of historic annual landings (MT) by Portugal of swordfish and estimates of catches of blue shark and short-fin mako in the South- eastern Atlantic (ICCAT area 96 and 97 combined), between 1995 and 2000 (dos Santos et al. 2002).

Despite the lack of records of the elasmobranch by-catch in these pelagic fisheries, some studies have been carried out. For example, the recent studies based on the EU observer’s programme (Elasmobranch by-catch of the French and Spanish Tuna Purse-seiner fleets in the eastern tropical Atlantic in 1997-99), reported the composition of the by-catch of elasmobranch species in the commercial purse-seine activities off West Africa conducted during 1882 fishing sets. The most important shark species in weight are the scalloped hammerhead (Sphyrna lewini), the other hammerheads (Sphyrna spp.), the silky shark (Carcharhinus falciformis) and manta rays (Table 2.4.2.). The strategy of this fishing activity is based on the use of artificial and natural FADs (Fishing Aggregating Devices) that attract small tuna schools. The slow-moving whale shark (Rhincodon typus) is considered by fishers as a natural FAD. The elasmobranch by-cacth was 0.34 % and 1.05 % in biomass of the total catch excluding or including the whale shark specimens corresponding to 448 and 1350 tonnes respectively.

The composition of the by-catch of the pelagic long-line fisheries in the Atlantic and Indian Oceans is less diverse than that of the purse seine. Mainly blue sharks (P. glauca) and mako sharks (Isurus spp.) are being caught, representing on average 2 - 4 % of the total catch in number.

Elasmobranch by-catches are reported in other EU overseas fisheries exploiting demersal resources. For example, the Patagonian toothfish (Dissostichus eleginoides) and the Mackerel Icefish (Champsocephalus gunnari) fisheries using bottom trawl and longline in the French EEZ of Kerkuelen and Crozet Islands in the Southern Ocean whose by-catch include the following species: sleeper shark Somniosus spp., porbeagle Lamna nasus and some sub-antarctic skates (Bahtyraja spp.).

Also pelagic EU fisheries off the coast of West Africa are known to have a significant by-catch of elasmobranchs.

Table 2.4.2. Numbers and weight of elasmobranchs (by family and species) caught as by-catch in non-associated school sets, log sets and sea mount sets by the French and Spanish tuna purse seiners in the eastern tropical Atlantic in 1997-1999. ______Taxa Common names Code N° N° N° Total W in W in W in Total in in in N° non-ass. log sets sea weight non-ass. log sea school in kg mount in kg school sets mount set set sets sets in kg in kg ______SHARKS MEGACHASMIDAE Megachasma pelagios megamouth shark - - 1 1 50 - - 50 ALOPIIDAE thresher sharks FAL ------Alopias superciolosus bigeye thresher shark ASU - 1 - 1 - - 99 99 Alopias vulpinus thresher shark AVU - 1 - 1 - 122 - 122 LAMNIDAE mackerel sharks FLA 11 1 - 12 875 50 - 925 Isurus oxyrinchus shortfin mako IOX 3 26 22 31 189 385 1345 1919 Carcharodon carcharias great white shark CCA 1 1 - 2 141 141 - 282 CARCHARHINIDAE requiem sharks FCA 4 73 63 140 120 2023 3150 5293 Carcharhinus falciformis silky shark CFA 161 362 5 528 4674 7216 110 12000 Carcharhinus longimanus oceanic shark CLO 10 174 9 193 385 6323 310 7018 Prionace glauca blue shark PGL 2 22 2 26 104 700 90 894 SPHYRNIDAE hammerhead sharks FSP 68 16 207 291 3325 752 10238 14315 Sphyrna lewini scalloped hammerhead SLE 30 10 829 869 1452 599 38961 41012 Sphyrna mokarran great hammerhead SMO - 3 2 5 - 141 94 235 Sphyrna zygaena smooth hammerhead SZY 25 7 1 33 1163 329 45 1537 UNIDENTIFIED SHARKS REX 6 11 1 18 300 550 50 900 TOTAL SHARKS 321 688 1142 2151 12778 19331 54492 86601 % 14.93 32.00 53.06 89.47 14.75 22.32 62.92 71.27 ______

______Taxa Common names Code N° N° N° Total W in W in W in Total in in in N° non-ass. log sets sea weight non-ass. log sea school in kg mount in kg school sets mount set set sets sets in kg in kg ______RAYS DASYATIDAE stingrays FDA 5 - - 5 13 - - 13 Dasyatis violacea pelagic stingray DVI 23 5 - 28 65 15 - 80 Dasyatis centroura roughtail stingray DCE 5 - - 5 715 - - 715 MYLIOBATIDAE eagle rays Myliobatis aquila common eagle ray MAQ 1 - - 1 8 - - 8 RHINOPTERIDAE cownose rays RHI 1 - - 1 40 - - 40 MOBULIDAE manta rays Manta birostris giant manta ray MBA 36 4 - 40 7258 800 - 8058 Mobula mobular Mediterranean manta MOM 60 1 - 61 8680 150 - 8830 Mobula spp. manta ray MOB 48 14 42 104 7200 1923 6890 16013 UNIDENTIFIED RAYS RAX 5 4 - 9 715 437 - 1152 TOTAL RAYS 184 28 42 254 24694 3325 6890 34909 % 72.33 11.06 16.60 10.52 70.73 9.52 19.73 28.72 TOTAL SHARKS + RAYS 505 716 1184 2405 37472 22656 61382 121510 % 20.97 29.79 49.23 35.71 30.83 18.64 50.51 RHINCODONTIDAE Rhincodon typus whale shark RTY 6 19 - 25 60000 183500 - 243500

TOTAL GENERAL 510 735 1183 2428 97472 206156 61382 365010 ______

3. Biological features 3.1. Species distribution and stock structure The following has been copied from the report of the ICES Study Group on Elasmobranch Fishes (ICES, 2002a) and is a description of the stock identity of the stocks considered in the DELASS project (APSC 99/055). Although this overview is limited to these nine species, the descriptions, which are to be elaborated in the final report of DELASS, can be considered as an example of the sort of information that is available for elasmobranchs.

3.1.1. Spurdog Spurdog has a world-wide distribution, but tends to be coastal. France, United Kingdom, Norway and Ireland all take spurdog in directed fisheries and as an important by-catch. Iceland has a small fishery, but it is not known to which stock these fish belong. There are no detailed studies on parasites nor on genetics and, though life history parameters are well established, different methodologies have been applied which make comparisons difficult. Several tagging experiments have been carried out which show that very few individuals cross the Atlantic, and indicate one stock around the British Isles and including the Norwegian Sea. Though there are Squalus spp landings in Sub-area VIII, these may be from a different species.

Stock assessed in DELASS: IIa, IIIa, IV, V, VI, VII.

3.1.2. Lesser spotted dogfish Though the species' geographical distribution extends from Senegal to Norway, it is generally not commercially exploited and the discard rate in the commercial fishery is very high (up to 90% in VIIIc). Some data are available for France and Portugal, but the only useful available data are from Div. VIIIc for Spain. Tagging has resulted in most recaptures being reported from within a distance of 10 miles from the release area and with no apparent relationship between time at liberty and distance travelled. It seems that the species' distribution is continuous but with localised aggregations which are consistent over time. In the Cantabrian Sea, juveniles are found mostly in the eastern part, in deeper waters than adults, and they also occur in colder water. However, no information is available from shallow coastal areas. English surveys almost never catch juveniles, though hundreds of egg cases are caught in the Bristol Channel. There have been few studies on life history parameters, though further north specimens grow bigger than in Spanish waters. Because lesser spotted dogfish do not show a clear geographical migration, an assessment could in principle be based on any arbitrary ICES division.

Stock assessed in DELASS: VIIIc (Cantabrian Sea).

3.1.3. Blue shark Results of US and Irish tagging studies show the blue shark to make extensive movements throughout the North Atlantic. There is little movement across the equator, or to the Mediterranean, indicating a single stock in the North Atlantic.

Stock assessed in DELASS: North Atlantic.

3.1.4. Cuckoo ray Cuckoo rays occur in the North Sea, Irish Sea (and perhaps further north to the west of Scotland) and Celtic Sea. Life history parameters are available for several areas, though ageing is difficult, and results from the Celtic Sea are similar to those obtained for the North Sea. For most rays, no landings data or length frequency distributions are available by species, but French data are available for cuckoo ray by area since 1985. Not much is known about migrations. Survey data are available from the IBTS surveys in western waters and there are additional English and Irish survey data.

Stock assessed in DELASS: Celtic Sea, area VIIg,h,j and VIII a,b

3.1.5. Thornback ray Most commercial landings data are for all Raja species combined and data by species are only available for France. However, survey data are available by species from the IBTS, quarterly from 1991 to 1996. Tagging data illustrate that fish do not move far, and there seems to be little mixing between the North Sea and the English Channel. Based on available literature, and analysis of the distribution patterns in survey data, the composition of the commercial landings and tagging data, the central and southern North Sea has been defined as the area in which a stock unit for R. clavata is appropriate.

Stock assessed in DELASS: IVb and IVc.

3.1.6. Blackmouth catshark This species is widely distributed over the NE Atlantic, and landings data are available for Spain and Portugal, with CPUE data from Norway and Ireland. It is heavily discarded in large-vessel fisheries in the north and in artisanal fisheries in the south. Abundance estimates and length frequencies are available from Portuguese and Irish deep-water surveys. Though it may be reasonable to nominate two stocks, one off the Portuguese continental coast and one in VII/VI, there are insufficient data to distinguish between them. It is possible that blackmouth catshark populations are essentially local (like lesser spotted dogfish), with one large population in which pseudo population segments can be distinguished.

Stock assessed in DELASS: area IXa.

3.1.7. Portuguese dogfish The Portuguese dogfish is distributed over the NE Atlantic from Iceland to Senegal and also occurs off South Africa in depths down to 3600 m. Landings data are available for France and Portugal, though France (and Ireland for 2000 and 2001) only have data for two species combined, C. coelolepis and C. squamosus, known as “siki”. There are also data from experimental fishing and surveys, from Norway, IEO, SAMS, MI (Girard, 2000). Very few small individuals have been recorded in the NE Atlantic. There is a lack of knowledge on migrations, though it is known that females move to shallower waters for parturition and vertical migration seems to occur (Clarke et al. 2001). Stock identity is difficult given that, for many countries, deepwater sharks landings often consist of several species.

Stock assessed in DELASS: NE Atlantic.

3.1.8. Leaf-scale gulper shark This species is distributed over the NE Atlantic from Iceland to Senegal, but landings data by species are only available for Portugal and the Azores. Data are available from the same experimental fishing and survey sources as for the Portuguese dogfish. Males and immature females dominate samples west of Ireland and Britain and at Hatton Bank, while individuals < 80 cm are only available in Portuguese surveys. Data on stock identity are inconclusive, though available evidence suggests that this species is highly migratory.

Stock assessed in DELASS: NE Atlantic.

3.1.9. Kitefin shark The fishery at the Azores started in the early 1970s, but data are fragmented. There are no tagging data, and no knowledge of horizontal migrations, but kitefin shark are caught wherever temperatures are around 10-11 °C. Norwegian data (Hareide and Garnes, 2001) suggest that D. licha mainly occurs in area X.

Stock assessed in DELASS: Sub-area X.

3.2. L-W relationships, conversion factors Allometric relationships are commonly used in ichthyology to characterized the morphology of the species. Some of these relationships are used by taxonomists in identification keys. These relationships are also used in fishery biology and management in order to estimate the weigth of the catches from length (total length or fork length) frequency distributions recorded on board of fishing boats or at landing sites.

Tables 3.2.1 and 3.2.2 provide some total length and fork length relationships and length/weight relationships for a number of species caught in the European fisheries. These data are compiled from some studies supported by EU (e.g. FAIR, DELASS), ICES reports and scientific litterature.

Table 3.2.1 Some allometric conversion factors for European sharks and rays. TL = total length; FL = fork length; Wth = disc width (for skates); DW = dressed/gutted weight; W = total weight

Species TL / FL relationships TL / W relationships References

Alopias vulpinus TL = 1,733 FL + 14,778 DW = 0,298 TL 0,974 97/50 DG XIV

Centrophorus granulosus W = 0,000338 TL 3,5902 FAIR CT 95 0655

Centrophorus squamosus W = 0,000373 TL 2,3591 FAIR CT 95 0655

Centrophorus squamosus W = 0,002072 TL 3,214 Irish Marine Inst. Survey

Centrophorus squamosus Male W = 2,10 x 10-5 TL 2,7 Girard, 2000

Fem. W = 1,10 x 10-6 TL 3,35

Centroscymnus coelolepis W = 0,167179 TL 2,3678 FAIR CT 95 0655

Centroscymnus coelolepis W = 0,0004583 TL 3,611 Irish Marine Inst. Survey

Centroscymnus coelolepis W = 0,0043 TL 3,12 ICES CM 1997/G :2

Centroscymnus coelolepis Male W = 2,10 x 10-5 TL 2,79 Girard, 2000

Fem. W = 5,10 x 10-7 TL 3,61

Centroscymnus crepidater W = 0,0024 TL 3,25 ICES CM 1997/G :2

Dalatias licha Male W = 5,13 x 10-5 TL 2,52 ICES CM 1997/G :2

Fem. W = 1,50 x 10-4 TL 2,35

Deania calcea W = 0,000190 TL 3,6890 FAIR CT 95 0655

Deania calcea W = 0,001230 TL 3,258 Irish Marine Inst. Survey

Deania calcea W = 0,0012 TL 3,26 ICES CM 1997/G :2

Etmopterus princeps W = 0,0028 TL 3,15 ICES CM 1997/G :2

Etmopterus spinax W = 0,002151 TL 3,1903 FAIR CT 95 0655

Etmopterus spinax W = 0,0018 TL 3,24 ICES CM 1997/G :2

Galeorhinus galeus TL = 59,9703 DW 0,315287 97/50 DG XIV

Galeorhinus galeus DW = 0,0099 FL 2,8838 DELASS (Spain)

Galeus melastomus W = 0,008609 TL 2,7347 FAIR CT 95 0655

Galeus melastomus Fem. W = 0,002 TL 3.05 ICES CM 1997/G :2

Male W = 0,002 TL 3.07

Galeus melastomus W = 0,0018 TL 3,1035 DELASS (Spain)

Isurus oxyrinchus TL = 1,134 FL – 1,811 TL = 66,7584 DW 0,323385 97/50 DG XIV

Lamna nasus TL = 1,115 FL + 12,883 DW = - 7,680 TL 2,050 97/50 DG XIV

Leucoraja naevus W = 2,36 x 10-6 TL 3,233 Charuau & Biseau, 1989

Leucoraja naevus TL = 0,5932 Wth – 1,1682 W = 0,0037 TL 3,1403 DELASS (Spain)

Mustelus asterias DW = 0,003 FL 3,1196 DELASS (Spain)

Mustelus mustelus DW = 0,0092 FL 2,8563 DELASS (Spain)

Pionace glauca TL = 1,175 FL + 4,103 DW = 1,787 x 10-6 TL 3,096 97/50 DG XIV

Raja clavata TL = 0,7167 Wth – 0,343 W = 0,0035 TL 3,1705 DELASS (Spain)

Raja montagui W = 0,0011 TL 3,4613 DELASS (Spain)

Scyliorhinus canicula DW = 0,0563 TL 2,3183 DELASS (Spain)

Scymnodon ringens W = 0,005118 TL 3,0857 FAIR CT 95 0655

Scymnodon ringens W = 0,0043 TL 3,12 ICES CM 1997/G :2

Sphyrna zygaena TL = 1,252 FL + 5,215 97/50 DG XIV

Squalus acanthias DW = 0,0035 FL 3,0626 DELASS (Spain)

3.2.1. Converstion factors From the nominal catches recorded at landing places, the equivalent fresh weight of the catch is calculated. Usually fishes are prepared on board (gutted, skinned, headed, finned, etc) before landing. For these calculations, the national fishery services use a series of conversion factors, i.e. ratios allowing the calculation of the “fresh biomass” from the landed weights. Althought these factors change with ontogenic changes for each species and also differ between populations, and seasons, fishery services tend to use the same conversion factors for every species, or more often for species categories whatever the composition of the catch is (juveniles, adolescents, adults). Sometimes, the way in which fish are processed varies, but the same factor is nevertheless used “by habit”!

In France, for example, the conversion factors were the same from1974 to 1992 and it was impossible to trace how they were originally calculated, except that they should correspond to a fresh weight, gutted weight, etc. The same ratio was used for all shark species (1.33) and all rays (1.21) (Séret, unpublished data). The average conversion factor for the sharks which is now being used is 1.04 (corresponding to the loss of 4% due to finning), which is far from the true value for several sharks, particularly for the deep-water sharks; for example, the conversion factor for “siki” (the commercial category consisting of C. squamulosus and C. coelolepis) should be 1,76 for the males and 1,76 for the felmales (Girard, 2000).

There is an urgent need to update the converstion factors for each European country, taking into consideration the fishing area, the ontogenic stage and the way of preparation for every major commercial chondrichthyan species.

Table 3.2.2 Further allometric conversion factors taken from literature sources.

Species TL / FL relationships TL / W relationships References

Alopias superciliosus FL = 0.5598 TL + 17.6660 W = 0.00911 FL 3.08 Kohler et al., 1995

Alopias superciliosus W = 0.0351 SL 2.44 Quevedo et al., 1984

Alopias superciliosus W = 0.00183 SL 3.45 Guitart Manday, 1975

Alopias vulpinus FL = 0.5474 TL + 0.8865 W = 0.0183 FL 2.52 Kohler et al., 1995

Carcharhinus altimus FL = 0.8074 TL + 0.9872 W = 0.00102 FL 3.46 Kohler et al., 1995

Carcharhinus brachyurus W = 0.0104 TL 2.9 van der Elst, 1981

Carcharhinus brevipinna W = 0.00751 TL 2.97 Branstetter, 1987

Carcharhinus falciformis FL = 0.8388 TL - 2.6510 W = 0.0154 FL 2.92 Kohler et al., 1995

Carcharhinus falciformis W = 0.00201 TL 3.23 Branstetter, 1975

Carcharhinus falciformis W = 0.00878 SL 3.09 Guitart Manday, 1975

Carcharhinus falciformis W = 0.0019 TL 3.19 Bonfil, 1990

Carcharhinus falciformis W = 0.0464 SL 2.75 Brouard et al., 1984

Carcharhinus falciformis W = 0.019 FL 2.93 Quevedo et al., 1984

Carcharhinus limbatus W = 0.00714 TL 3.01 van der Elst,1981

Carcharhinus limbatus W = 0.0144 TL 2.87 Branstetter, 1987

Carcharhinus melanopterus W = 0.00325 TL 3.65 Lyle, 1987

Carcharhinus obscurus FL = 0.8396 TL - 3.1902 W = 0.0324 FL 2.79 Kohler et al., 1995

Carcharhinus obscurus W = 0.00945 TL 2.93 van der Elst, 1981

Carcharhinus plumbeus FL = 0.8175 TL + 2.5675 W = 0.0109 FL 3.01 Kohler et al., 1995

Carcharhinus plumbeus W = 0.00419 TL 3.48 Bonfil et al., 1990

Carcharhinus plumbeus W = 0.0058 TL 3.31 Stevens et al., 1991

Carcharias taurus W = 0.0106 TL 2.94 van der Elst, 1981

Carcharodon carcharias FL = 0.9442 TL - 5.7441 W = 0.00758 FL 3.09 Kohler et al., 1995

Carcharodon carcharias W = 0.00827 TL 3.14 Compagno, 1984

Species TL / FL relationships TL / W relationships References

Carcharodon carcharias W = 0.00321 TL 3.18 van der Elst, 1981

Centroscyllium fabricii W = 0.0009 TL 3.42 Gordon et al., 1994

Centroscymnus coelolepis Fem. W = 0.00061 TL 3.71 Yano et al., 1984

Centroscymnus coelolepis Male W = 0.0231 TL 2.81 Yano et al., 1984

Centroscymnus coelolepis W = 0.0043 TL 3.12 Gordon et al., 1994

Centroscymnus crepidater W = 0.0024 TL 3.25 Gordon et al., 1994

Centroscymnus owstoni Fem. W = 0.00102 TL 3.61 Yano et al., 1984

Centroscymnus owstoni Male W = 0.0463 TL 2.68 Yano et al., 1984

Cetorhinus maximus W = 0.00494 TL 3.00 Bigelow et al., 1948

Dasyatis pastinaca W = 0.0251 DW 3.11 van der Elst, 1981

Deania calcea W = 0.0012 TL3.26 Gordon et al., 1994

Etmopterus princeps W = 0.0028 TL 3.15 Gordon et al., 1994

Etmopterus spinax W = 0.0018 TL 3.24 Gordon et al., 1994

Etmopterus spinax W = 0.003 TL 3.13 Merella et al., 1997

Galeorhinus galeus W = 0.0068 FL 2.94 Hurst et al., 1990

Galeorhinus galeus W = 0.0109 TL 2.83 van der Elst, 1981

Hexanchus nakamurai W = 0.00124 FL 3.47 Brouard et al., 1984

Himantura uarnak W = 0.0848 DW 2.72 van der Elst, 1981

Himantura uarnak W = 0.0624 DW 2.83 van der Elst, 1988

Isurus oxyrinchus FL = 0.9286 TL - 1.7101 W = 0.00524 FL 3.14 Kohler et al., 1995

Isurus oxyrinchus W = 0.05 FL 2.32 Quevedo et al., 1984

Isurus oxyrinchus W = 0.0012 FL 3.46 Guitart Manday, 1975

Lamna nasus FL = 0.8971 TL + 0.9877 W = 0.0148 TL 2.96 Kohler et al., 1995

Leucoraja naevus W = 0.00236 TL 3.23 Dorel, 1986

Odontaspis ferox W = 0.00589 TL 3.00 Bonfil, 1995

Prionace glauca Fem. W = 0.0131 TL 3.2 Stevens, 1975

Prionace glauca Male W = 0.00392 TL 3.41 Stevens, 1975

Species TL / FL relationships TL / W relationships References

Prionace glauca FL = 0.8313 TL + 1.3908 W = 0.00318 FL 3.13 Kohler et al., 1995

Pristis pectinata W = 0.00171 TL 3.04 van der Elst, 1981

Pteromylaeus bovinus W = 0.00025 DW 3.84 van der Elst, 1981

Raja asterias W = 0.0018 TL 3.27 Merella et al., 1997

Raja brachyura W = 0.00281 TL 3.23 Dorel, 1986

Raja clavata Fem. W = 0.00843 TL 3.30 Ryland et al., 1984

Raja clavata Male W = 0.00187 TL 3.17 Ryland et al., 1984

Raja clavata W = 0.0024 TL 3.20 Merella et al., 1997

Raja clavata W = 0.00319 TL 3.19 Dorel, 1986

Raja clavata W = 0.00324 TL 3.20 Dorel, 1986

Raja microocellata Fem. W = 0.00489 TL 3.41 Ryland et al., 1984

Raja microocellata Male W = 0.00893 TL 3.31 Ryland et al., 1984

Raja microocellata W = 0.00494 TL 3.12 Dorel, 1986

Raja miraletus W = 0.00246 TL 3.29 Moutopoulos et al., 2000

Raja miraletus W = 0.001 TL 3.44 Ungaro, 2001

Raja miraletus W = 0.0018 TL 3.25 Merella et al., 1997

Raja montagui Fem. W = 0.00364 TL 3.44 Ryland et al., 1984

Raja montagui Male W = 0.00183 TL 3.24 Ryland et al., 1984

Raja montagui W = 0.00201 TL 3.31 Dorel, 1986

Raja polystigma W = 0.0003 TL 3.78 Merella et al., 1997

Raja radula W = 0.00515 TL 3.07 Moutopoulos et al., 2000

Raja undulata W = 0.00415 TL 3.12 Dorel, 1986

Rhizoprionodon acutus Fem. W = 0.00233 FL 3.14 Kasim, 1991

Rhizoprionodon acutus Male W = 0.00964 FL 2.85 Kasim, 1991

Rhizoprionodon acutus W = 0.0079 TL 2.99 Krishnamoorthi et al., 1986

Rhizoprionodon acutus W = 0.0151 TL 2.72 van der Elst, 1981 Scyliorhinus canicula W = 0.00364 TL 2.78 Dorel, 1986 Scyliorhinus canicula W = 0.0016 TL 3.16 Merella et al., 1997

Species TL / FL relationships TL / W relationships References

Scyliorhinus canicula W = 0.00308 TL 3.03 Dorel, 1986

Scymnodon ringens W = 0.0043 TL 3.12 Gordon et al., 1994

Sphyrna lewini Fem.W = 0.00282 TL 3.13 Chen et al., 1990

Sphyrna lewini Male W = 0.00135 TL 3.25 Chen et al., 1990

Sphyrna lewini FL = 0.7756 TL - 0.3132 W = 0.00777 FL 3.07 Kohler et al., 1995

Sphyrna lewini W = 0.0126 TL 2.81 Branstetter, 1987

Sphyrna lewini W = 0.00556 TL 3.16 Letourneur et al., 1998

Sphyrna lewini W = 0.00399 TL 3.03 Stevens et al., 1989

Sphyrna mokarran W = 0.00123 TL 3.24 Stevens et al., 1989

Sphyrna zygaena W = 0.00142 TL 3.3 van der Elst, 1981

Squalus acanthias W = 0.00396 TL 3.00 Gunderson et al., 1988

Squalus acanthias W = 0.00147 TL 3.22 van der Elst, 1981

Squalus blainvillei Fem. W = 0.0037 TL 3.07 Cannizzaro et al., 1995

Squalus blainvillei Male W = 0.0033 TL 3.09 Cannizzaro et al., 1995

Squalus blainvillei W = 0.012 TL 3.37 Merella et al., 1997

Squalus megalops W = 0.0116 TL 2.78 van der Elst, 1981

Squalus megalops W = 0.0126 SL 2.88 Brouard et al., 1984

3.3. Maturity Maturity ogives are only available for some of the species caught in Community fisheries. Table 3.1 presents the available data for the ICES area.

Table 3.1. Length (L50) and age (Age50) at 50% maturity of some elasmobranchs taken in Community fisheries.

Species Sex L50 (cm) Age50 Area Reference

Centroscymns coelolepis m 86 NE Atlantic

f 102 Girard & DuBuit, 2000

Centrophorus squamosus m 98 NE Atlantic

f 104 Girard & DuBuit, 2002

Deania calceus m 85 NE Atlantic

f 105 Clarke et al. 2002b

Centroscymnus crepidater m 52 NE Atlantic

f 68 Clarke et al. 2002

Squalus acanthias m

f 74 NE Atlantic Fahy, 1989

Scyliorhinus canicula m

Raja batis f 180 11 Celtic Sea DuBuit, 1976

Raja brachyura f 84 Irish Sea Gallagher et al. 2002

Raja clavata f 72 10 Irish Sea Holden 1972; 1976

Raja fullonica f 85 North Sea Walker and Hislop, 1998

Raja montaguii f 58 8 Irish Sea Holden 1972; 1978

Raja naevus f 59 8 North Sea Walker and Witte, unpublished

Raja oxyrinchus f 120 Wheeler, 1978

Raja radiata f 40 5 North Sea Walker and Witte, unpublished

4. Selectivity parameters of fishing gear There have been few studies of selectivity of fishing gears for elasmobranchs in Community fisheries. The main gear types that are used in these waters in elasmobranch target or by-catch fisheries can be summarised as follows:

4.1. Demersal trawls Many elasmobranchs are taken in demersal trawl fisheries, mainly as by-catch (Section 1). However it is not clear how selective trawls are for most demersal elasmobranchs in shelf waters. Rays and skates are caught as target or by-catch in beam and otter trawl fisheries and anecdotal reports from fishermen suggest that towing speed is an important parameter in selectivity. In order to catch rays some vessels tow as fast as 7.5 knots, slow speeds result in reduced catches.

There is no information on trawl selectivity for shelf-dwelling sharks or dogfish. However demersal trawls are not very effective at targeting fast-swimming species

such as spurdog, Squalus acanthias, that is a by-catch in demersal trawl fisheries. It should be considered that larger specimens can escape trawls, and this may suggest that mature females are less vulnerable to this gear.

Research has been carried out on size selectivity for deepwater sharks. A comparative study of trawl and demersal longline was carried out based on Irish deepwater surveys (Fig. 4.1). It should be noted that smaller specimens are totally absent from Sub-areas VI and VII. This absence is not due to gear selectivity. There were no significant differences in the length frequency distributions from trawl and longline for leafscale gulper shark Centrophorus squamosus. However there were significant differences for Centroscymnus coelolepis (KS test, p<0.05), for which longlines took smaller specimens. This indicates that trawl only selects a part of the population of this species, smaller specimens appeared to be distributed off the bottom, out of the range of trawls but attracted to baited hooks (Clarke, 2000). Length frequencies for male Deania calceus from each fishing method were not significantly different (KS test p<0.05). However for this species longlines selected for significantly larger (p<0.05) females than trawls; modal length from trawling was 85 cm in contrast to 105 cm for longlines (Clarke et al. 2002b). Selectivity ogives for D. calceus, mainly a discard species, show that trawl has a lower Age50 than longline (Fig. 4.2). In contrast, trawl selected larger female C. coelolepis than longline (Fig. 4.3).

4.2. Demersal longlines Trawls and long-lines are fundamentally different fishing methods. Trawls herd fish into the opening of the net, while fish are attracted to long-lines by the smell of the bait. This results in both size and species selection (Hareide, 1995). It has been demonstrated that long-lines tend to select for larger teleost fish than trawls (Hareide, 1995; Jørgensen, 1995). There has been little study of selectivity of longlines for elasmobranchs. But some of the findings for teleosts are applicable. Hareide (1995) points out that larger specimens of certain species avoid trawls but are caught on longlines. Since the swimming speed of a fish is proportional to its body size, larger fish will be hooked more rapidly than smaller fish. Furthermore, research on cod Gadus morhua shows that larger fish tend to frighten away smaller ones from baited hooks (Bjordal and Lokkeborg, 1996).

One effect of size selectivity is that more mature fish will be caught by long-lines, and with heavy fishing this could be harmful to the spawning stock of teleost fish. However Hareide (1995) suggests that fishing of the older part of the stock results in less risk of over-exploitation than fishing of the younger year classes. This effect was demonstrated for the deepwater species, birdbeak dogfish Deania calceus (Fig. 4.2). It was also demonstrated for male C. coelolepis, though not for females (Fig. 4.3). This indicates that longline is not always a more size selective fishing method for sharks, than trawl (Clarke et al. 2002a).

Bait size, rather than hook size is considered to be the most important parameter affecting longline size selectivity, with smaller fish tending to favour smaller prey items (Bjordal and Lokkeborg, 1996). Results from Irish longline surveys (Clarke, 2000; Connolly et al., 1999) show that commercial (13/0 EZ) hooks and baits select for a broad size spectrum of squaliform sharks representing the entire length range of free-swimming specimens of the species under study. Comparisons of catch

composition in deep waters west of Ireland show that longline catches deeper than 500m are dominated by sharks, and species diversity is quite low. In contrast trawl catches have a higher species diversity, have many more teleost species, and though elasmobranchs are well represented, they are not dominant. These data show also that discarding from longline is mainly of non-commercial small squalid sharks (Clarke et al. 2002a; Connolly and Kelly, 1996). Trawl discards are composed of more species, but significant quantities of some sharks are discarded (Clarke et al. 2001; 2002b).

There is no information on selectivity of demersal longlines for shelf-dwelling species. Longline fisheries for spurdog and porbeagle do exist, but it is not clear what size ranges of sharks are targeted by these fisheries. Norwegian fisheries for spurdog off northern Scotland were prosecuted by longline, and targeted fish of 80 cm and upwards (Holden, 1965; 1968). There are longline catches of demersal shelf-dwelling rays in some areas, but selectivity is unknown.

4.3. Demersal gillnets There is little information on the selectivity parameters of demersal gillnets for elasmobranchs in any Community fisheries. There are some gill net and tangle net fisheries for coastal dogfish and rays in Community waters. There is no information on selectivity, but the latter gear can be considered to have very few selectivity parameters for elasmobranchs.

Gillnets are extensively used in the deep waters of the Community. They target monkfish and hake, and sometimes are used to target deepwater sharks (Pineiro et al. 2001). Whilst gillnets are considered to be a highly selective method there is no information available on these fisheries, and effective effort is not regulated. Tangle net fisheries, such as those targeting monk and deepwater sharks are unlikely to be selective at all.

4.4. Pelagic trawls Anecdotal information suggests that pelagic sharks are taken in some pelagic trawl fisheries but information on selectivity is totally lacking.

4.5. Pelagic longlines The main pelagic longline fisheries of the Community are those targeting tunas and swordfish, and there are significant by-catches of sharks in these fisheries (Anon. 2001). There is no information on selectivity for sharks in these fisheries.

However some research has been carried out on a small longline fishery targeting blue shark in Basque Country (Spain). Each vessel uses a 15 miles line and 1000 hooks (75 x 40 mm). There are no discards of blue sharks because all the individuals are over 65 cm fork length. The sex composition of blue shark landings is about 65% of females and 35% of males. The rest of catches belong to other pelagic sharks as porbeagle and shortfin mako (less than 0.5% on average of total landings in number in last three years). Catches of non-shark species are very scarce, only one tuna fish, one swordfish and some individuals of Raja spp. were reported by the fleet in last two years.

4.6. Pelagic gillnets In south Australia pelagic gillnets have been shown to be an efficient and selective means of targeting the smaller, faster growing cohorts (Walker et al. 2002). Thus gillnets have many advantages over other methods for targeting sharks. However, the Australian shark fishery targets sharks and is relatively clean. There are few examples of this in Community fisheries that mainly take elasmobranchs as by-catch. For Community fisheries there is little information on selectivity for this gear. Pelagic sharks were caught in gillnet fisheries for tunas, but these fisheries have been discontinued. For spurdog, one study was carried out by Fahy (1989) on the southwest Ireland fishery, which used the 6.4 cm knot to knot salmon gillnet. The study showed that gillnets were size selective, but the mesh size in use selected for females above size and age at maturity, thus impacting on the spawning stock. A similar effect of gillnet mesh size was described by Jones and Geen (1977) in the NE Pacific. These results suggest that mesh size regulation could have utility as a management measure for spurdog, and other sharks. It should be noted that female girth varies with reproductive stage and that smaller mesh sizes will target immature females and males (Fahy, 1989).

It is important to consider the relative efficiencies of the various gears involved in catching particular species or species groups.

Centroscymnus coelolepis

Female Male 200 200 180 180 160 160 140 Trawl n = 88 140 Trawl n = r e 120 120 111 b Long-line n = 632 Nu Long-line n = m 100 100 u mb 394

N 80 er 80 60 60 40 40 20 20 0 0 65 75 85 95 105 115 125 135 145 65 70 75 80 85 90 95 100105110 TL (cm) TL (cm)

160 Male Long-line n = 449 100 Female 140 90 Trawl n = 99 80 120

70 r 100 e r

Long-line n = 413 b e 60 b m 80 u m 50 Trawl n = 77 u N

N 40 60 30 40 20 10 20 0 0 80 85 90 95 100 105 110 115 120 125 130 135 140 145 85 90 95 100 105 110 115 120 125 TL (cm) TL (cm)

120 Female 500 450 Male 100 400 80 Long-line n = 389 350 r r Long-line n = 970 e e 300 b Trawl n = 88 b m 60 m 250 Trawl n = 164 u u

N N 200 40 150 20 100 50 0 0 65 70 75 80 85 90 95 100 105 110 115 120 65 70 75 80 85 90 95 100 105 110 TL (cm) TL (cm)

Fig. 4.1. Comparison of length frequencies from Irish trawl and longline surveys of the Rockall Trough in 1997 (Clarke et al. 2002a).

1 0.9 0.8 0.7 d e t 0.6 c e l 0.5 Trawl e

s 0.4

. Longline

P 0.3 0.2 0.1 0 0 2 4 6 8 10 12 14 16 18 20 Age estimate

Fig. 4.2. Estimated selectivity ogives for Deania calceus, combining both sexes, derived from catch curve analyses. Estimated Age50 (trawl) = 11 and Age50 (longline) = 15 (Clarke et al. 2002a).

1 .2 C . c o e lo le p is fe m a le

0 .8 d e

t T r a w l c e l 0 .6

e L o n g lin e s

P 0 .4

0 .2

0 1 4 7 1 0 1 3 1 6 1 9 2 2 2 5 2 8 3 1 3 4 3 7 4 0 4 3 4 6 4 9 A g e e s tim a te

C . c o e lo le p is m a le s 1

0 .8 d e t 0 .6 T r a w l c e l

e L o n g lin e s

0 .4 . P 0 .2

0 1 4 7 1 0 1 3 1 6 1 9 2 2 2 5 2 8 3 1 3 4 3 7 4 0 4 3 4 6 4 9

A g e e s tim a te

C . c o e lo le p is s e x e s c o m b in e d 1

0 .8 d

e T r a w l t 0 .6 c e l L o n g lin e e s

0 .4 . P

0 .2

0 1 4 7 1 0 1 3 1 6 1 9 2 2 2 5 2 8 3 1 3 4 3 7 4 0 4 3 4 6 4 9 A g e e s tim a te

Fig. 4.3. Estimated selectivity ogives for C. coelolepis, derived from length-converted catch curves developed with hypothetical von Bertalanffy growth parameters (Clarke et al. 2002a).

Length frecue ncy distribution of Prionace glauca combined sex es (2000) 1200

1000

) 800 n (

y c n

e 600 u q e r

F 400

200

0 65 75 85 95 105 115 125 135 145 155 165 175 185 195 205

Le ngth (cm)

Length frecue ncy distribution of Prionace glauca by sex (2000)

4500 male 3750 female

) 3000 n (

y c n

e 2250 u q e r

F 1500

750

0 65 75 85 95 105 115 125 135 145 155 165 175 185 195 205 Le ngth (cm)

Fig. 4.4. Length frequencies for blue shark from Basque longline fishery.

5. Past and recent trends in abundance Stock identity and distribution for most of the elamobranchs are unknown, which makes it difficult to interpret any abundance index result. For the cases where a fairly good knowledge of the distribution of the species exists, the available information on abundance often covers only a small proportion of the known distribution area. As a result, a bias in the abundance trend may be introduced. Detailed spatial information of catch and effort by species, area and gear may be necessary to map the fishery distribution and better visualise the catches and effort along the stock distribution, and analyse if a particular time series of CPUE is representative of stock abundance. Tagging information will improve the understanding of stock identity, mixing rates between areas, and the definition of management units.

The collection of landings data for elasmobranch species is still considered a problem. In particular, landings need to be separated at least to the species level and, in most fisheries, this is not the case. Some elasmobranch species may be subject to substantial discarding rates (e.g. lesser spotted dogfish). Effort data are usually not available because most of the shark species are caught as a by-catch (e.g deep water species). Therefore most of the fishery catch per unit of effort may not be a reliable index of abundance of the stocks and detailed analysis of the available data is needed to evaluate if the CPUE is an accurate index for the species.

Surveys targeting elasmobranchs do not exist up to date. Available data are from surveys targeting other species, usually not designed for elasmobranchs and sometimes not designed for abundance estimates. As a result, also CPUE from surveys may not be an accurate index of species abundance. Therefore, an effort is necessary to analyze available data to compute abundance indices from surveys and to estimate the statistical significance of changes in the abundance estimates.

The overview presented in this chapter is a summary of the information available from the reports of the ICES Study Group on Elasmobranch Fishes (SGEF) and the Working Group on Deep Water Species (WGDEEP). Further information may be available elsewhere and for other species, especially information on pelagic sharks may be available from ICCAT reports, but these were not available to the group. Short or long term projections were not made for any elasmobranch species.

5.1. North Atlantic

5.1.1. Spurdog (Squalus acanthias) in Sub-areas IV, VI and VII Although spurdog may occur throughout the water column, research vessel surveys using otter trawls are considered to provide representative samples. Beam trawls are less suitable for catching spurdog. Most computerised databases and standard surveys do not extend back before the 1970’s, so the time period for fishery-independent data is limited.

Table 5.1.1 summarises the CPUE data available from eight research survey series carried out within the species’ distribution area. The majority of the CPUE series exhibit a decline, especially those recorded within ICES Sub-areas IV and VII by the

UK (E&W) survey series. This is in contrast to the Scotia GOV series carried out further to the north and in the Div. VIIa Lough Foyle survey. The data require further analysis for elaboration of the spatial differences in the signals from the survey series.

Table 5.1.1 Mean catch per unit effort (kg.hr-1) from English, Northern Irish and Scottish groundfish surveys (ICES, 2002a).

Vessel Cirolana Cirolana Cirolana Corystes Explorer Lough Foyle Scotia Scotia Scotia Scotia Gear GOV Granton PHHT Granton Aberdeen Trawl Rockhopper Otter Trawl Aberdeen Trawl Deepwater Trawl GOV Monkfish Trawl 1977 2.50 147.19 1978 10.23 11.35 1979 2.41 11.54 1980 9.44 0.54 1981 7.53 12.53 1982 5.72 12.67 1.21 1983 6.15 2.66 0.66 6.22 1984 3.30 16.25 0.69 2.84 1985 4.95 13.82 1.66 35.95 1986 28.56 11.23 1.08 9.20 1987 13.54 22.83 7.62 0.35 1988 4.69 5.68 8.36 2.55 8.91 1989 1.20 5.26 0.39 0.71 2.97 1990 2.30 5.14 3.55 0.78 7.04 44.48 1991 3.58 0.49 1.30 3.53 6.03 0.10 5.75 1992 3.14 0.83 3.70 3.74 0.24 4.67 1993 0.96 1.24 7.30 0.35 4.47 1994 2.56 1.10 1.48 0.12 5.50 1995 1.44 0.58 3.85 0.04 3.48 1996 0.26 3.22 0.07 0.00 2.78 0.00 1997 0.53 1.18 2.54 0.19 0.00 1.61 1998 0.32 0.81 5.04 0.62 1.97 0.00 1999 0.18 14.44 3.61 0.00 2.61 1.80 0.00 2000 0.06 0.94 3.42 0.15 6.25 14.39 2001 0.47 1.26 1.65 0.42 Mean CPUE 1.23 6.87 6.28 3.91 36.63 3.81 1.06 0.68 5.90 11.78

5.1.2. Lesser spotted dogfish (Scyliorhinus canicula) Table 5.1.2 shows available fishery and survey abundance indices for lesser spotted dogfish in ICES area VIIIc.

The total fishery CPUE series from Spanish trawlers in ICES area VIIIc shows an increasing trend from 1991 to 2001 with a pronounced peak in the last two years. This tendency is also observed for data from the Aviles port (Spain), though the peak in CPUE in the last period is not so noticeable.

Survey data show that this species is quite abundant on the continental shelf and is one of the most important terms of biomass after the commercial species blue whiting, horse mackerel, megrim, and hake. The biomass indices show no trend, though there are annual fluctuations and high levels in 1990, 1997 and 2001 (Table 5.1.2).

Table 5.1.2. Fishery CPUE estimated for Spanish trawlers in ICES area VIIIc, and bottom trawl survey abundance indices (derived from surveys carried out in autumn to estimate hake recruitment in the Cantabrean Sea, ICES area VIIIc2).

Effort Landings from at Aviles Aviles CPUE Total Total CPUE Survey Years Port Port Aviles landings effort total index

1991 65.555 7.681 8,53 144.077 7.045 20,45 4,79

1992 59.833 12.692 4,71 131.501 8.110 16,21 6,13

1993 43.967 7.635 5,76 96.630 6.948 13,91 5,15

1994 76.989 9.620 8,00 169.200 7.505 22,54 5,33

1995 87.682 6.146 14,27 192.708 4.608 41,82 3,45

1996 89.929 4.525 19,87 177.316 3.809 46,55 5,34

1997 77.551 5.061 15,32 155.196 4.049 38,33 6,32

1998 70.461 5.929 11,88 162.496 3.845 42,26 5,19

1999 79.078 6.829 11,58 150.768 4.232 35,63 4,7

2000 78.369 4.453 17,60 199.000 3.367 59,10 6,26

2001 68.682 2.385 28,80 213.000 2.031 104,87 6,83

5.1.3. Portuguese dogfish (Centroscymnus coelolepsis) There are few specific fishery data available for this species. Fishery CPUE from French bottom trawls is available from 1990 to 2001 but only for the combined species, Portuguese dogfish and leaf-scale gulper shark, collectively called “siki” (Figure 5.1.1). CPUE presents a declining trend except for 2000 and 2001. However this non target CPUE may not be a reliable estimator of the abundance (see ICES , 2002a and ICES, 2002b for details).

Abundance data available for the species are provided in Table 5.1.3. Surveys show a decreasing trend in abundance from 1997-2000 in area VI. In areas VII and XII the abundance also seems to decline.

120

100 ) r u

o 80 h

/ g k

( 60

E U

P 40 C

0 1990 1992 1994 1996 1998 2000 Year

Figure 5.1.1 CPUE for Centroscymnus coelolepis and Centrophorus squamosus from the French reference bottom trawl fleet as presented to WGDEEP (ICES, 2002b).

Table 5.1.3 CPUE (kg/1,000 autoline hooks; kg/hour trawled) data for C. squamosus and C. coelolepis from Norwegian and Irish research surveys in the NE Atlantic. Gear configurations were the same for both countries.

Sub Area Country Date Gear C. squamosus C. coelolepis Combined 600 - 1,000 1,100 - 1,600 600 -1,600

VI Ireland 1997 Autoline 218 70 133 VI Norway 1999 Autoline 219 83 178 VI Norway 2000 Autoline 42 92 86 VI Ireland 2000 Autoline 24 76 38

VII Norway 1996 Autoline 221 227 264 VII Ireland 1997 Autoline 56 158 69 VII Ireland 1999 Autoline 51 107 61 VII Ireland 2000 Autoline 73 166 81

XII Norway 1999 Autoline 100 128 174 XII Norway 2000 Autoline 78 98 113 XII Ireland 2000 Autoline 38 19 33

XIV (b) Norway 1991 Autoline 8 8

VI Ireland 1993a Trawl 55 62 VI Ireland 1993b Trawl 63 8 49 VI Ireland 1995 Trawl 15 11 14 VI Ireland 1996 Trawl 48 9 37 VI Ireland 1997 Trawl 24 25 20

VII Ireland 1993a Trawl 6 32 VII Ireland 1995 Trawl 242 197 VII Ireland 1996 Trawl 30 26 27 VII Ireland 1997 Trawl 6 15 15

5.1.4. Kitefin shark (Dalatias licha) Data available for the Azorean (ICES X) targeted fishery are given in Table 5.1.4. Abundance declined according to the hand line catches from 1978 to 1984 and remained low with high variability, probably related with market considerations. According to the gillnet fishery, abundance decreased from 1990 to 1998. But again, catches and landings are likely to be influenced by market considerations, and fishery CPUE may not reflect abundance trends, particularly not for the last decade.

Table 5.1.4. Catch and CPUE for the kitefin shark fishery in the Azores by fleet component (bottom gillnet and handline). Total catch values can exceed sum of both fisheries because by-catch of other fisheries or from unknown sources is included.

Handlines Bottom gillnets Total Catch (mt) CPUE (kg/man/day) Catch (mt) CPUE (kg/net/day) Catch Year mean mean (mt)

1972 14,7 72,58 14,7 1973 22,3 102,83 22,3 1974 161,4 142,54 161,4 1975 97,4 176,95 97,4 1976 11,8 166,22 11,8 1977 153,9 224,32 188,0 1978 196,4 260,44 196,4 1979 232,7 214,57 232,7 1980 226,5 181,59 396,1 27,22 658,4 1981 173,7 119,44 667,2 9,85 947,0 1982 59,6 121,81 81,9 9,48 141,6 1983 90,9 112,87 83,4 17,57 220,3 1984 95,2 71,95 842,0 36,59 937,4 1985 73,8 80,27 814,4 55,52 902,5 1986 63,5 127,63 663,0 53,62 741,0 1987 117,9 156,85 290,3 41,52 413,2 1988 62,6 105,26 443,3 79,61 548,9 1989 105,8 187,56 452,1 72,99 559,8 1990 100,9 103,94 492,0 83,85 601,8 1991 87,6 104,28 793,9 79,96 896,3 1992 64,3 86,46 672,2 23,37 760,8 1993 40,9 178,92 550,4 33,14 591,3 1994 49,8 104,66 258,7 41,39 309,0 1995 51,1 175,48 269,4 36,81 320,9 1996 68,4 243,46 147,7 29,22 216,4 1997 29,9 121,8 23,61 151,9 1998 29,9 6,3 22,49 40,4 1999 23,6 31,3 2000 22,8 0,1 31,0 2001 10,6 0,9 12,7

5.1.5. Thornback ray (Raja clavata) ICES area IVb,c

Rays and skates are mainly caught as by-catch in demersal mixed fisheries in the North Sea. The available catch data are for all species combined. There are no effort data specifically for rays and skates.

The main survey for which data are available for North Sea rays and skates is the ICES co-ordinated International Bottom Trawl Survey (IBTS). Abundance time series for the major species caught during the IBTS since 1975 are presented in Figure 5.1.2. No marked trend is observed in the time series for Raja clavata. However, additional historical survey data from English and Dutch surveys in the North Sea show a clear change in the distribution of the species (Fig 5.1.3), suggesting a decline in the geographical range of the Raja clavata stock since the start of 20th century. Local populations, especially in the southwestern North Sea, seem to survive.

ICES area X

Data from the demersal longline survey from the Azores are available and presented in Figure 5.1.4. Raja clavata is found mainly in the coastal areas of the islands (representing 95% of the total abundance), at depths between 50 and 600 meters with a higher abundance in the shallow strata (Fig. 5.1.4a). The low abundance at banks and seamounts is likely to be due to the limited shallow habitats available in this sub area, where the minimum depth is usually 150-200 m.

The annual RPN shows a decrease from 1995 to 2001. The annual differences were not considered statistically significant (Fig. 5.1.4b). Abundance in 1995 was estimated from a survey with a different stratification. Variability for this year is considerably.

Figure 4.8.4 Time series of abundance (number per hour) for 8 ray species caught during the quarter 1 International Bottom Trawl Survey in the North Sea

radiata clavata

15 2.5

12 2.0

9 1.5

6 1.0

3 0.5

0 0.0 19 75 19 80 19 85 19 90 19 95 20 00 19 75 1980 19 85 1990 19 95 2000

naevus montagui

2.5 0.4

2.0 0.3

1.5 0.2 1.0

0.1 0.5

0.0 0.0 1975 19 80 1985 19 90 1995 20 00 19 75 19 80 19 85 1990 1995 20 00

batis brachyura

0.25 0.15

0.20 0.12

0.15 0.09

0.10 0.06

0.05 0.03

0.00 0.00 19 75 19 80 1985 19 90 19 95 2000 1975 1980 19 85 19 90 19 95 2000

circularis fullonica

0.04 0.04

0.03 0.03

0.02 0.02

0.01 0.01

0.00 0.00 19 75 19 80 19 85 1990 1995 20 00 1975 1980 19 85 19 90 19 95 2000

Figure 5.1.2. Time series of abundance (number per hour) for 8 ray species caught during the ICES coordinated first quarter IBTS surveys in the North Sea (from ICES, 2002a).

1900

1990

Figure 5.1.3 Distribution of thornback ray (Raja clavata) in the southern North Sea based on English and Dutch research vessel surveys in the early 1900s and international data from the International Bottom Trawl Survey and the Beam Trawl Survey in the 1990s (From ICES, 2002a)

4 a)

P 2 R

0 1 1 5 2 0 3 4 5 0 5 1 0 - 0 0 0 5 1 1 - 1 1 1 1 1 0 ------1 2 0 3 4 5 6 5 0 0 0 0 0 0 0 0 0 0 0 0

Depth stratum 1995 1996 1997 1999 2000 2001

Raja clavata (I-VI) b)

15 N P R 10

0 1994 1995 1996 1997 1998 1999 2000 2001 Year

Figure 5.1.4. Relative Population Numbers (RPN) of Raja clavata from the Azorean demersal longline survey: a) annual abundance by stratum and b) annual abundance. There are no data for the year 1998.

5.1.6. Cuckoo ray (Leucoraja naevus) Standardized abundance indices from fishery data are available for the ICES area IV, VII and VIII during 1986 to 1998 (Fig.5.1.5). Survey data are available (EVHOE surveys) from 1987 to 2000 (ICES, 2002a).

The trends in abundance suggest that the stock had a low size in the early 1960s followed by a recovery in the 1990s (Fig. 5.1.5). The recent trend is not clear (there are no fishery data available), with survey data suggesting a decrease since the late 1990s.

1.2

1.1 CPUE

1 x e

d 0.9 n I 0.8

0.7

0.6 1986 1988 1990 1992 1994 1996 1998 2000

1.6

1.4 EVHOE

1.2

1 x e

d 0.8 n I 0.6

0.4

0.2

0 1986 1988 1990 1992 1994 1996 1998 2000

Figure 5.1.5. Cuckoo ray in sub-areas IV-VIII. Results of GLM analysis for CPUE and survey data (EVHOE). Index of year effects. (from ICES, 2002a).

5.2. Mediterranean Sea Historical data on the past abundance of pelagic and coastal Elasmobranchs are reported for the Northern Tyrrhenian Sea area by the analysis of catch data of a local tuna-trap that operated in the Gulf of Baratti at the end of the 19th and the beginning of the 20th century. A short but significant historic data series is availablefor the period 1898 to 1922. The 24 years period analyzed, clearly shows a decrease of the catches both in number and in weight. After this period the tuna trap gave no more significant yields. Some species disappeared from the catches (e.g. the angelsharks, Squatina sp. and the tope shark Galeorhinus galeus). This coincided with the introduction of active fishing gear (bottom trawl) and urbanization and industrialization of the area.

Two research projects carried out in the Adriatic Sea in 1948 and 1998 respectively, provide information on the changes that occurred in the species composition and distribution of bottom-dwelling fishes over a 50-years period. The study provided valuable information about the Mediterranean, for which basin very few long-term fishery studies exist. The comparison between the two surveys highlights the decrease of elasmobranch biodiversity and occurrence in the last samples (1998), especially for to the group of batoids (rays and skates).

Biological features such as size and age at sexual maturity, fecundity, size at birth and growth rates appeared to be determining factors, since small sized species such as the lesser spotted dogfish (S. canicula) or the brown ray (R. miraletus) were frequently collected in both surveys, while bigger shark species and most other rays disappeared or were rarely found during the 1998 survey.

Common bony fishes (teleosts) were collected with similar frequency in both surveys. Therefore, the sensitivity of elasmobranchs (mostly the biggest and slow-growing species) to the fishery is shown once more, and in this study specifically for the Mediterranean Sea.

Another interesting set of historical data on elasmobranch catch trends in the Mediterranean was reported for Northern Adriatic waters for the period 1904-1932. During the years immediately following World War I, a substantial increase in abundance of elasmobranchs in the landings of the Fiume and Trieste Ports was noted (Figure 5.2.1). This was correlated to the fishing ban during the war period that enabled the recovery of stocks, particularly those of “predator” fish species.

l a s t g o n t i

e 30 n h t a )

l f

s o e h

t c h h n c 20 t g a i a r e c Trieste b w o

n m 10 Fiume i

s a l % ( E 0 1904 - 1932

Figure 5.2.1. Trend of elasmobranch catches (percentage of the total fish landings) in the Trieste and Fiume fishing ports during the period 1904-1932 (from D’Ancona, 1934, modified).

6. Stock Status 6.1. Introduction This chapter provides an overview of different assessment methods (6.2), then discusses vulnerability and stock status (6.3), and finally different aspects of the conservation status are discussed (6.4).

6.2. Assessment methods This overview is based entirely on a similar overview of assessment methods applied to the data for 9 species of elasmobranchs studied in the DELASS project (CFP 99/055), which was presented in the report of the ICES Study Group on Elasmobranch Fishes (ICES, 2002a). One assessment method, not further discussed in the following overview, but which is certainly worthwile to consider, is the analysis of species vulnerability (see also Section 6.3.1).

6.2.1. Life table models Life table models use the demographic characteristics of a population in the form of a schedule of the survivorship and 'fertility' at each age for the entire (female) population. These methods allow the calculation of reference parameters of population growth, such as the generation time (G), net reproductive rate (R0), population doubling time (tx2), and the observed rate of increase of the population (r). This last parameter can be used as an input parameter for stock assessment methods such as surplus production models, or to define the prior probability distribution of the intrinsic rate of increase for use in a Bayesian Surplus production model (McAllister and Pikitch 1998, McAllister et al. 2001) as is illustrated for spurdog (see section 4.1 in ICES (2002)).

In order to be able to use life table models, biological parameters for the species are required. In ICES (2002), life table models have been applied to blue shark with reasonable success. However, it was found that the biological basis for the application of life table models is often relatively weak. Therefore, it is important that more ageing and growth studies are carried out, and also that estimates of maturity and fecundity at age and at length become available. Since the life table models are heavily dependent on the calculated survivorship, the estimates of natural mortality also need to improved.

6.2.2. Surplus production models For many elasmobranch species, length- or age-based data are either limited or not available. In these cases, surplus production models may provide a suitable alternative. These models are generally applicable when historical series of catch are available and CPUE series from either fisheries or surveys.

CPUE data from the commercial fisheries can, in principle, be the cause of pitfalls. In order to be able to use CPUE as an indicator of stock size (as is done in a surplus

production model), the catchability should be constant. If catchability is not constant during the history of the fishery (e.g. due to technological improvements or specific targeting of certain species), CPUE may just as well be an indicator of the technological success of the fishery, rather than of the size of the stock.

In order to be able to run surplus production models, it is not strictly necessary to have data at the species level. In ICES (2002), an example is provided for two combined deep-water sharks (so-called ‘Siki’). However, this approach runs the risk of missing the separate trends in the species, as opposite trends could be hidden. For that reason, species-specific data are urgently needed.

The ‘Siki’ assessment in ICES (2002) also showed the need to define strict procedures for determining when CPUE can be considered to be an indicator of stock size when issues, such as a developing fishery and possible mis-reporting whilst creating track records when TACs are announced, are applicable.

In addition to ‘Siki’, ICES (2002) explored surplus production models for Cuckoo ray and lesser spotted dogfish.

6.2.3. Growth models Growth models like the Von Bertalanffy equation and the associated parameters play an important role when direct age compositions of catches or surveys are not available. Growth parameters are essential for the life table models and for the slicing of length distributions into age compositions (from the commercial fishery or from research surveys). Growth parameters are also important for purely length-based models, such as the catch at size method (Sullivan et al, 1990).

For many of the stocks considered in ICES (2002), several studies with growth data were available. However, the estimated growth parameters were often found to be dependent on the method or the data used to estimate growth, and thus cannot be generically applied. There is clearly a need to evaluate the sensitivity of the assessment models to the growth parameters used.

A problem that was identified for a number of stocks was that the L∞ from the growth model was substantially lower than the maximum length found in the length compositions of the commercial or survey catches. This created problems in slicing length distributions and also in applying the catch at size method (e.g. for spurdog).

It should be noted that reliable growth data will be difficult to collect when age information is scarce and seldom validated. Tagging data could be an important remedy for this deficiency.

6.2.4. Length-based methods Two length-based methods were explored by the Study Group on Elasmobranch Fishes (ICES, 2002a): length-based catch-curve analysis and catch at size analysis. Both aim to give estimates of the level of exploitation experienced by the stock.

The length-based catch-curve analysis is not presented in ICES (2002), but could be an alternative to an age-converted catch curve. However, its successful application to elasmobranch data has still to be demonstrated.

The catch at size method was explored for spurdog and lesser spotted dogfish. This method uses a size-transition matrix, obtained from a stochastic growth model with known VBG parameters, to project the population length distribution forwards in time. All population dynamics processes, such as recruitment and fishing mortality, are assumed to be dependent on length rather than age. Estimates of yearly recruitment, length distribution of recruits, selectivity and temporal fishing mortality are then obtained by fitting the annual catch-at-length predicted by the model to the observed data. Problems were encountered with this method because a large number of individuals occurring in the catch were significantly larger than the values of L∞ obtained from the literature. The model assumes that growth beyond L∞ is impossible and is, therefore, unable to predict the proportion of large individuals appearing in the catch. Further work on this method is encouraged, since the method was considered to be potentially very useful.

6.2.5. Catch at age analysis Catch at age analysis of elasmobranchs has so far only been based on length- converted age compositions, as there are no direct estimates of frequencies at age available from the landings.

A separable VPA may be used to explore the consistency of the catch-at-age matrix (however that is derived) and the sensitivity of the model to different assumptions of terminal F at age and terminal selection at the oldest true age. In ICES (2002) a separable VPA was explored for spurdog and lesser spotted dogfish.

When age-based information is available from surveys, a separable model of survey- only catches could be applied (Cook, 1997). This model assumes that F is separable into an age and year effect, and that the population size of a cohort at a given age can be expressed as the product of its initial cohort strength and its cumulative mortality. Assuming that age-disaggregated survey indices are related to abundance at age by age-dependent catchabilities, the model estimates of these values can be fitted to the observations to obtain estimates of age, year and year-class effects. These parameters can then be used to obtain estimates of relative number at age, stock biomass and yield.

Results from initial runs of this model applied to lesser spotted dogfish with various values of q at the youngest age gave either unrealistically high selectivity for this age class or very low mean estimated F. A closer consideration of the survey indices indicated that the assumption of constant q at older ages may not be valid, as increasing numbers of individuals from the same year class were caught through time. This would explain the very low estimates of F obtained in these initial runs. Other assumptions about the relative catchabilities at age may, therefore, be more appropriate and these should be further explored.

6.2.6. General Linear Models (GLM) analysis Although not formally listed as a ‘stock assessment method’, it was found that the application of GLM could provide a very useful insight into the development of some stocks. In ICES (2002) this method was mainly applied to thornback and cuckoo ray. In the example of thornback ray in the North Sea, GLM analysis enabled the modelling of CPUE indices from the IBTS survey. This gave insight in structure of the catches, first in terms of the number of hauls where thornback rays were caught, and second in the number of individuals in hauls where they were caught. This led to the conclusion that the number of successful hauls had decreased, but that the number of fish per successful haul was more or less constant. Further work in this direction is to be encouraged as survey data of relatively high quality are readily available.

6.2.7. Bayesian approach The Bayesian approach, such as that applied to spurdog, are a general class of statistical methods that could be applied to evaluate the contribution of uncertainty in a wide range of input data (e.g. growth, CPUE, catch) on the stock assessment results. Although Bayesian analyses may take a long time to compute, there are also major advantages. The possibility to define prior distributions of parameters from comparable species or species groups, for example, allows the application of these methods even when estimates of certain parameters for the stock considered are not available (see also Hammond et al., 2002).

6.2.8. Overall conclusions The overall conclusions and expectations of the ICES Study Group on Elasmobarnch Fishes (ICES, 2002a) regarding stock assessments of elasmobranch species were:

• Considerable progress had been made in making input data for stock assessment of elasmobranch species available. The application of several stock assessment models to the DELASS case study species proved to be fruitful and could direct future research in this areas.

• The SG expected that, in the near future, better documentation of the input data would be available and that a formalised exchange format for data would be implemented.

• The SG further expected that the consistency of different assessment models could be evaluated for most of the stocks considered. A major aim of the SG had been to explore different modelling approaches to the same data, so that the perception of the status of the stock could be confirmed (or shown to be false) from different models. Based on these analyses, it should be possible to identify the most suitable models for each stock.

If ICES will be asked to provide management advice on elasmobranchs, the SG on Elasmobranch Fishes (ICES, 2002a) considered that lack of data would be the main obstacle, and that the focus should continue to be on the collection of catch and effort data, survey data and biological data.

6.3. Vulnerability and stock status

6.3.1. General There are few data to evaluate the stock status of most species. However vulnerability to fishing pressures can be gauged from analyses of available life history data, the depth of analysis depending on the quality of the data. Other approaches to assessing vulnerability from the perspective of biodiversity conservation have included assessing the vulnerability to fishing gears and other human impacts, value of products taken from a particular species and behavioural or geographic factors. i) Life history characteristics, particularly those that confer a low reproductive potential and a low capacity for population increase following depletion by fisheries or other negative impacts (Holden 1974). The most vulnerable species are those with low fecundity, slow growth, late maturity, long life, production of large, precocious young and having high survival of all age classes. Where sufficient data are available, the combined effects of these life history characters on a species’ ability to rebound from a depleted state may be integrated into an estimate of r: annual rate of population increase, or rebound potential (Smith et al. 1998). It is, of course, only rarely possible to define r, but size may offer a useful surrogate. In general, smaller-sized elasmobranchs have a tendency to mature earlier, be shorter-lived and to have higher rates of population increase, although this may not be the case for squalid dogfish and deepwater species (Walker 1998). Conversely, larger species, particularly when they are also long-lived, have less capacity to sustain exploitation or to recover from it. ii) Restricted range or habitat, particularly for endemic species, species with a range that is restricted in other ways (e.g. deepwater species found in a relatively shallow depth range or species confined to shallow coastal waters which may be subject to fishing activity throughout their range and isolated from potential sources of recolonisation), and species reliant at some stage in their life cycle on a critical habitat that is itself under threat (either through intrinsic habitat fragility, or due to its proximity to centres of human activity). iii) Morphological or behavioural characteristics, which may render species even more vulnerable to fishing mortality. Examples are the tooth-studded rostrum of the sawfishes, Pristidae, which appear to have been extirpated from European and Mediterranean waters, and the tendency for white sharks to investigate vessels, making them particularly vulnerable to target trophy angling.

The above three characters may be combined in a semi-quantitative manner in order to provide an assessment of the Vulnerability of stocks or species.

FAO (2000) classified the above characters as bio-ecological risk, and also identified two other factors that may predispose species to depletion and extinction risk: iv) Value or economic risk (related to the profitability of exploitation, derived by offsetting fishery cost against product value); and v) Violability or compliance risk (the extent to which conventional fisheries management measures may be circumvented).

It is necessary to combine the above factors with information on the size of the population being assessed in order to achieve a final assessment of threatened status. Thus populations that are highly restricted in number and area are more threatened than large, widely-distributed and wide-ranging populations that are subject to similar fishing mortality or that have undergone similar levels of depletion. Finally, the past, current and projected future extent and rate of population depletion are important elements to include when assessing the threatened status of populations. In elasmobranchs, excessive fishing mortality will usually be the factor driving population declines, although other environmental factors may also contribute.

6.3.2. Stock status and vulnerability, as interpreted by ICES WG’s and for case story species for the DELASS project The ICES WGDEEP includes elasmobranch species in their assessments and the group has tried to evaluate vulnerability and stock status for some deepwater sharks. Even though ICES SGEF by definition deals with elasmobranchs, its meeting in May 2002 focused on assessment methodology and to a lesser extend on the assessment results and status of nine “case study” species. In addition to assessment, SGEF was asked to evaluate the quality and suitability of data for the listing of threatened and declining elasmobranchs by OSPAR. The ICES Advisory Committee on Ecosystems (ACE) has further commented on that list of species. The following section summarizes the results of mainly the ICES’ work on vulnerability and stock status of elasmobranchs.

6.3.2.1. Deepwater sharks There are few data with which to evaluate stock status for deepwater elasmobranchs. A ranking of species life history parameters was used by the ICES ACFM in 2001, in response to a request for advice on deepwater species by NEAFC (ICES, 2001). The parameters chosen were longevity, the Brody growth parameter K, age at maturity, length at maturity, annual fecundity and natural mortality. All the main deepwater species (teleosts as well as elasmobranchs) were ranked and the average rank was used to produce a list of the species in order of vulnerability. The deepwater sharks Centrophorus squamosus and Centroscymnus coelolepis were shown to have the most K-selected life histories of the deepwater species.

A somewhat more detailed approach was used by Clarke et al. (in press). In this study, the surrogate population growth rate r’ (Jennings et al. 1998) was used to compare shelf and deepwater species, including deepwater sharks. Again, the deepwater sharks were found to be the most vulnerable. Based on the combined results of Clarke et al. (in press) and ICES (2001) the vulnerability of three deepwater sharks, for which data are available, can be presented as follows, in order of decreasing vulnerability:

Centrophorus squamosus < Centroscymnus coelolpeis < Deania calceus.

The status of the stocks of these deepwater species is not clearly understood. The DELASS project considers that one biological stock of C. coelolepis and one stock of C. squamosus resides in the ICES area. Only a combined CPUE series is available, for Sub-areas V, VI and VII. It shows a decline to 1999, but an upward trend in 2000 and 2001. This upward trend is not reflected in Irish and Norwegian survey data and is not considered accurate. The downward trend in CPUE is less informative because the two species have differing bathymetric ranges and important trends may be masked in the combined series. However it is clear that CPUE declined through the 1990’s, but we don’t know the trend of the individual species.

Some general points about the impacts of fishing on these shark populations can be made. A maturity stage segregation according to the depth is a feature of these species. Gravid C. coelolepis are found only at the top of the continental slope (Clarke et al., 2001; Girard and DuBuit, 1999) so that variation in the fishing strategy can differently impact the stock. The use of a combined series also ignores important aspects of life history in each species. C. squamosus may have been subject to exploitation for longer. It has a lower fecundity than C. coelolepis (Girard and DuBuit, 1999). However a portion of the stock is not subject to exploitation, gravid females being absent from this area. In contrast, all stages of C. coelolepis are present in this area, and this species could be more vulnerable for that reason.

There are less data on the stock status or vulnerability of other deepwater sharks. It is known that Centrophorus granulosus is caught in ICES Sub-areas VIII and IX (Anon. 2002) and in the western Mediterranean (Guallart, 2002). There have been declines in landings of this species in ICES Sub-area IXa (Table 2.2.10), but it is not clear whether this is indicative of stock trends or fluctuations in the price of liver oils. However, in the western Mediterranean, Guallart (2002) states that catch rates decline after several weeks of fishing and recovery times are from some months to 2 years. This author reports that this species has an extremely low reproductive potential, with a fecundity of only one embryo and a likely gestation period of 1-2 years. Thus it can be regarded as more vulnerable than any of the other deepwater sharks.

6.3.2.2. Skates and rays Where data are sufficient to calculate r, the intrinsic rate of population increase, this parameter offers a very useful index of vulnerability. Walker and Hislop (1998) used a Leslie matrix to derive estimates of r for five ray species in the North Sea and to estimate replacement total mortality, the rate of Z that results in r = 0. A ranking of the species based on replacement Z in order of decreasing vulnerability was as follows:

Raja batis < Raja clavata < Raja brachyura < Raja montagui < Raja naevus < Raja radiata

An increase in total mortality will result in declines in abundance in this order (Walker and Hislop, 1998). Raja radiata has increased in relative abundance in the

North Sea, whilst Raja batis and Raja clavata have declined (Walker and Heessen, 1996).

A simple tabulation of the time trend in relative abundance of Raja species in the North Sea IBTS 1967-2002 surveys done by ICES (2002a) supported the ranking of vulnerability.

ACE (2002) concluded, in accordance to the proposed vulnerability, that Raja batis has declined throughout its range. The magnitude of decline is differentially well documented in various areas, but it is known to have severely declined in most shelf areas.

The SGEF assessment of Raja clavata showed a clear decline in abundance and distribution area of this species in the North Sea.

ACE concluded that Raja montagui (spotted ray) has declined in some areas in the eastern and southern North Sea, but is still common, with little evidence of decline in the western North Sea.

6.3.2.3. Coastal dogfish and catsharks The approaches outlined above are best suited to analysing assemblages of species taken in similar fisheries or occupying particular spatial or trophic niches. There have not been studies of the relative vulnerabilities of other elasmobranch assemblages in Community fisheries. Many key parameters are lacking for coastal dogfish and catsharks and for pelagic sharks. It would be useful to consider the relative vulnerabilities of spurdog, smoothhound, starry smoothhound, lesser and greater spotted dogfish. Similarly the relative vulnerabilities of pelagic sharks taken in Community fisheries could be examined.

The preliminary assessment (ICES 2002a) of NE Atlantic spurdog (Squalus acanthias) showed as steep decline in abundance.

ICES (2002a) concluded for lesser-spotted dogfish (Scyliorhinus canicula) in the Cantabrian Sea that although the results of the assessment contain large uncertainties and should not be used to provide advice, it appears that the stock is increasing in size.

6.3.2.4. Pelagic sharks There is no information with which to assess vulnerability or stock status of the blue shark. The SGEF carried out a preliminary analysis of this species, using a life table approach. The results were preliminary in nature, and the analysis was exploratory. Catch data are incomplete, but are collated by ICCAT. In spring 2002 a meeting was held in Dublin, under the aegis of the DELASS project, involving ICES, ICCAT and scientists having assessment data for this species. ICES and ICCAT will work together towards an assessment of blue shark in the north Atlantic, in 2004.

6.4. Conservation status

6.4.1. Introduction Assessments of the conservation status of elasmobranch species (which may also be referred to as their ‘threatened status’, or ‘extinction risk’) are potentially required under a number of national, regional and international instruments and associated work programmes. Unfortunately these do not all apply the same assessment methods, only a few require quantitative or semi-quantitative analysis (and these not to the same level of detail as stock assessments undertaken in fisheries analyses, although several recognise the value of Population Viability Analysis, where possible), while some are arguably wholly subjective and descriptive in nature. On the other hand, the lack of data for many species makes detailed and precise quantitative analyses of conservation status infeasible, requiring the use of semi-quantitative assessments backed by best available knowledge both of the species under consideration and its better-known relatives, and a precautionary approach should be applied.

The most important criteria for assessing the conservation status are given in section 6.3.

6.4.2. Levels of extinction risk Examples of how some of the criteria for assessing the conservation status are currently being used to prepare assessments of elasmobranch conservation status are given in the following section. It is, however, useful first to explain how extinction risk may be defined at several levels, from commercial, to ecological, to genetic and biological extinction.

In a fisheries context, it is often assumed that commercial extinction will always precede biological extinction by a significant margin of safety for the species concerned. Thus, target fisheries will collapse of their own accord when stocks are reduced to the point where it is no longer economically viable to pursue them and, relieved of fishing pressure, the stocks will recover. Unfortunately, the notion that economic extinction precludes biological extinction is uncertain in those cases where the value and economic risk (as defined by FAO) is so high that even a very small stock may be pursued, or where economic costs are not a consideration (as in a recreational trophy fishery). An even greater risk is posed by mixed-species fisheries, where all species are subject to the same fishing effort and similar fishing mortality rates. Under this situation, long-lived species with very low productivity may be driven to extinction while more numerous and fecund species continue to support the fishery (Camhi et al. 1998, Musick 1995).

Some species of elasmobranch are considered to play a keystone role in the marine ecosystem – indeed this is recognised by the reference in the FAO IPOA-Sharks to the protection of ecosystem structure and function. When their populations are reduced to such a low level that they are no longer able to fulfil their ecological role; they may then be considered to be ecologically extinct.

6.4.3. Conservation status assessment methods Assessments of conservation status are required under several national, regional and international instruments and programmes concerned with sustainable utilisation and conservation of natural resources. They vary considerably in their methodology; some are very qualitative and poorly defined, others seek to use quantitative assessments to the extent to which available data permit detailed analyses.

6.4.3.1. The IUCN Red List of Threatened Species The IUCN Red List of Threatened Species is the most widely used (globally) and readily available list of threatened species. It endeavours to use clear, transparent and quantitative assessment criteria that can be applied to all species. Although the Red List has no statutory basis, it is often used by governments, wildlife management organisations and non-governmental organisations to set priorities for conservation action. It aims firstly to provide global assessments of extinction risk, but where data are available can also incorporate assessments for separate populations.

The Red List has two main goals:

• To provide a global index of the state of the degeneration of biodiversity; and

• To identify and document those species most in need of conservation attention if global extinction rates are to be reduced.

The chondrichthyan fishes are one of the taxonomic groups selected by IUCN as important biodiversity indicator species that will enable IUCN to understand patterns of biodiversity change by undertaking regular analyses of their status. Thus, the first comprehensive assessments of all chondrichthyan fishes will provide IUCN with a baseline. Subsequent reassessments may be used regularly to monitor the status of this representative set of marine species. The Shark Specialist Group is responsible for producing and regularly updating Red List assessments for all chondrichthyans and is currently undertaking a programme to assess all 1,000+ species within its remit, both on a global basis and, where data are available, for stocks or regional populations.

For more information see www.redlist.org or IUCN (2001)

6.4.3.2. Convention on International Trade in Endangered Species (CITES) CITES lists species on Appendices that confer different levels of management of international trade in products from listed species, depending upon their status or degree of extinction risk. The following four criteria for assessing the status of species or populations are given in CITES Resolution 9.24 and its Annexes. These criteria are currently under review in an attempt to make them more quantitative (recommendations for amendments to the criteria, some of which are similar to the new IUCN Red List criteria, will be discussed by the 12th Conference of Parties in November 2002); since these amendments have not been agreed, it is mainly the existing definitions that are paraphrased/summarised here:

1. Small wild population size (also characterised by declining number of individuals, or area or quality of habitat; small sub-populations; majority of individuals concentrated in one sub-population; large short-term fluctuations in numbers; biological or behavioural vulnerability of species).

2. Restricted area of distribution (also characterised by fragmented or fluctuating distribution, biological vulnerability of species, and observed, inferred or projected decrease in: area of distribution, area of habitat, number of sub-populations, number of individuals, quality of habitat and recruitment/reproductive potential).

3. Decline in numbers (either ongoing or past but with potential to resume; or inferred or projected in the future on the basis of decrease in area or quality of habitat, levels or patterns of exploitation, or other factors)

4. Likely to satisfy one of 1-3 within the next 5 years.

Criterion 3, decline in numbers, is most likely to be of relevance to chondrichthyan fish species. Guidelines are provided for percentage population declines that might trigger listing, but these are rather general. Recommendations have been made to further define these during the current review of the CITES criteria. The FAO has taken a particular interest in the review of the CITES criteria – this is described below.

FAO review of the suitability of the CITES criteria for listing commercially- exploited aquatic species

Following an FAO Technical Consultation held in June 2000 (FAO 2000a), the 24th Session of FAO COFI (2001) requested the FAO Secretariat to prepare a background paper detailing the analysis of the CITES listing criteria and proposing a scientific framework for evaluating the status of commercially-exploited aquatic species for such listing. This document undertook an important analysis of potential extinction risk in such species, of particular relevance for biologically-vulnerable species like the chondrichthyan fishes.

6.4.4. Case studies: Porbeagle (Lamna nasus) There are inadequate data on global trends in porbeagle stocks, particularly those in the southern hemisphere, to assess the extent to which the world population has declined as a result of fishing pressure (although it is inferred that this highly valued species has been impacted by fisheries in most parts of its range). The IUCN Shark Specialist Group therefore assessed the global population as Lower Risk (near threatened) in 2000, with regional assessments of Vulnerable (A1bd) for the depleted, unmanaged population in the northeast Atlantic, and Lower Risk (conservation dependent) for the northwest Atlantic, in recognition of the introduction of the US and Canadian Fisheries Management Plans (IUCN 2000). It is now known that the northwest Atlantic stock is at 11-17% of virgin biomass (DFO 2001).

The Mediterranean population of porbeagle (where the species is considered to be very rare and only occasionally fished) is listed on Annex 3 (‘List of species whose

exploitation is regulated’) of the Specially Protected Areas and Biodiversity Protocol of the Barcelona Convention for the protection of the marine and coastal environment of the Mediterranean. This Protocol requires each member state to adopt strategies, plans and programmes for the sustainable use of marine and coastal resources and to incorporate these activities in their domestic management and legislative frameworks. Porbeagles are also listed on Annex III (Animal species whose exploitation must be regulated in order to keep their populations out of danger) of the Bern Convention for the Conservation of European Wildlife. The geographical restriction of these measures to the Mediterranean was apparently to avoid infringing management measures that might be (but, with the exception of quotas for Norway and Faroese vessels, have not been) implemented through the Common Fisheries Policy in European waters outside the Mediterranean.

Castro et al. (1999) assessed the status of the porbeagle for FAO, concluding (on the basis of the declines described above for the Northeast and Northwest Atlantic) that this species fell within Category 4 (Species in this category show substantial historic declines in catches and/or have become locally extinct). ‘Intensive fisheries have depleted the stocks of porbeagles in a few years wherever they have existed, demonstrated that the species cannot withstand heavy fishing pressure.’

7. Reproduction and habitat Elasmobranchs produce in general a low number of large, fully developed offspring with a relatively low natural mortality. Internal fertilization is followed by an embryonic development within the females or within large leathery egg cases that are laid and continue to develop and hatch outside the female. For many species of both groups, the gestation period is unknown, but may range from less than three months to more than 24 months.

Knowledge about the breeding season is rather poor for most species. Due to the production of relatively large egg cases or pups, breeding may take place over a rather long period, without distinct peaks.

In fish, habitat requirements may change during different life stages. Breeding and nursery areas may be included in the stock distribution area for the adults. Some shark and ray species are known to give birth in coastal or estuarine nursery grounds. These productive shallow areas provide both abundant food resources and shelter from predators. The “egg laying” elasmobranch species deposit their eggs in locations where they are likely to survive undamaged until the pups emerge and where the conditions for pups are favourable. In general, the knowledge of such species-specific breeding areas is quite poor, however, the requirements for undisturbed habitats are probably the same for both elasmobranchs and teleosts.

Some information does exist on spawning areas, especially for rays and Scyliorhinids. Survey data may be a useful means of identifying such areas and management of such species could benefit of protection of such zones. An extensive data-mining study would be necessary to document the sparse information that is available for different species.

8. Research and monitoring needs Management and conservation of elasmobranchs, as well as of other fishes, must be based on the biological capacity of the stocks themselves and information about the major threats – in most cases the fishery. This will require better knowledge of the species biology and ecology in addition to data from the fishery. There are gaps in the knowledge base for most exploited Community fish stocks. But the situation is more acute in the case of elasmobranchs. There are few cases where accurate landings data exist, and the knowledge of biological parameters is limited, several studies having been carried out many years ago. The following section describes categories of data and research needed for assessments of stock status.

8.1. Biological data and research Elasmobranchs have many life-history characteristics that are more akin to mammals and reptiles, than bony fish. The sorts of assessments that can be applied to elasmobranchs can include demographic type models, that rely on basic biological information. Some data are available on the biology of these species and progress has been made (Chapter 3), however there are critical gaps in the knowledge base for many species. The sorts of information required include:

• Species identification expertise • Population parameters: o Maturity and fecundity o Growth and mortality o Stock structure and genetics • Habitat requirement for different life stages • Biodiversity, food web and ecosystem. 8.2. Fisheries data and research The data types often used in traditional assessments in Community waters, catch, effort, CPUE and age-structured abundance indices are simply not available for elasmobranchs at present. Few species-specific series of catch data exist, for example. Whilst demographic models have considerable applicability for elasmobranchs, basic fisheries dependent data are also urgently required. Such data can be summarised as follows:

• Historical and recent total catches by species • Catch Per Unit Effort by species, (and by depth for deepwater sharks) • Total catch in numbers by species • Discard mortality • Gear selectivity parameters • Fleet descriptions; • Socio-economic data.

It may never be possible to segregate all elasmobranchs in landings, but sampling in ports and possibly at sea, can be used to estimate the species composition of catches.

8.3. Fisheries independent data The Sub-group considered that research institutes hold considerable amounts of survey data. Such data are of higher quality than fishery dependent data and may have utility for assessing elasmobranch stock status:

• Standardized data collection (e.g. trawl catches) and reporting on surveys for stock abundance estimates;

• Presence/ absence data on rare species may be the only data that actually exist;

• Surveys may provide possibilities to sample for biological parameters, especially for rarer species;

8.4. Gaps in current knowledge and future research and monitoring A full inventory of required data does not exist for any species, but the scarcity of data is particularly acute for most elasmobranchs taken in Community fisheries. The DELASS study contract has considerably strengthened Community capacity in the area of elasmobranch assessment methodologies. However application of these methods for many elasmobranch species is precluded by lack of even the most basic information, such as catch data. The number of elasmobranch species makes it almost impossible to have a detailed assessment of each species, so data sampling for extended assessment should focus on the most important species, in terms of recent or historical catch levels. Taking a simple life-history approach to assessing vulnerability might be the best approach for the remaining species. Thus a “twin-track approach” is envisaged: more detailed data collection schemes for the main commercial species, and a more general approach for assessing the vulnerability of by-catch, and discard species.

8.4.1. Improvements to the EC Programme Framework Programme on Data Collection The sorts of data that are required for detailed assessments can, partly, be provided by the EC-funded Sampling Regulation National Programmes, by requiring member states to collect specified data. Elasmobranchs are usually taken in mixed species fisheries, and landed as mixed species groups, as body parts (e.g. livers, ray wings or shark fins) or as processed products (e.g. frozen fish fillets), which makes it difficult to obtain data by species on total catch weight and number. A first step towards stock assessments is an overview of national landings with respect to species compositions and estimated quantity. Such data exist for some areas, but available catch data are often quite poor or missing. High priority in the National Programmes must be given to establishment of market surveys and observer programmes to get an overview of species compositions and landings magnitude, where such are missing.

The Sampling regulation in its current form is tailored to provide data for the routinely assessed teleost and crustacean stocks. It is not well suited to addressing the needs of assessment of the main elasmobranch stocks. Focus should be put on detailed species-specific data on length, weight, sex, age maturity etc. Selection of species for collection of such data can be based, on member states’ share of landings.

Another improvement in this programme would be to consider straddling or highly migratory species of sharks in sufficient detail. This is an important consideration for pelagic sharks, taken by Community fisheries in international waters, in several oceans. It is also important for deepwater sharks, taken by Community fisheries in international waters. The range of these deepwater species appears to extend widely within Community waters and beyond, so data collection should comprise wide areas within Community waters and NAFO and CECAF waters too.

Surveys are provided for, in detail, under the current programme. Data from scientific surveys for abundance estimates are very important for assessments. For some elasmobranchs, survey data are almost the only data source for trends in abundance and stock distribution. Some surveys do only record part of the catches and priority should be given to actually sample all elasmobranch species on surveys. Historical data series have shown, that the species identification expertise has been poor on some surveys. Maintenance and improvement of species identification skills should have a high priority. Therefore the regulation should be modified to require species specific data collection of elasmobranchs on surveys.

There are some taxonomic problems with the regulation. For highly-migratory species, the taxonomic category should read “Lamnidae, and Characharhinidae” not “Squalidae”. In Mediterranean waters it should read “Elasmobranchii” not “Selachii”. In the NAFO area the taxonomic groups should consider “Squalidae” in addition to “Rajidae”. The regulation could be significantly improved by requiring species- specific data, rather than merely referring to broad taxonomic groups.

8.4.2. Data requirements not met by Sampling Regulation Elasmobranchs are in general long-lived animals with low productivity and have a close relation between stock and recruitment. This gives the possibility to include the methodology normally used for mammals (demographic, life history matrix approaches) in addition to the methods used for stock assessment of teleost fishes. The demographic models have the advantage that they can be applied quickly, quicker than the time required to assemble traditional time series for these vulnerable species. This approach has been demonstrated to good effect by Walker and Hislop (1998) for North Sea rays, but for other Community elasmobranchs some improvements in data are needed. Foremost among these needs are age estimates (only available for some species), age specific estimates of natural mortality and some knowledge of reproduction, especially gestation period.

The data requirements outlined above could be obtained by means of a dedicated project with very specific aims, and clear objectives about the exact data types required for particular assessments. Such an initiative would offer a rapid means to

compensate for the hitherto poor data quality that has precluded the application of the assessment techniques available.

Archive survey information on stock distribution and abundance for elasmobranchs exists for many areas. Often, these observations and times series have not been computerized or used in stock assessment. These historical data might be an important source of information for stock abundance in periods with lighter fishing pressure than today. Furthermore data can be used for biodiversity analysis. The establishment of (computerized) archives of validated historical data and analysis of data have a high priority. Some progress has been made on this in the ICES area by the DELASS project, but there are still data to be collated. More work could be applied in Mediterranean and non-Community waters.

In some cases, species-specific catch and effort data are only available from commercial transactions data. Such data could be particularly important for rays and deepwater sharks, where available data are rarely species-specific. More exploration of existing catch and effort series should be carried out. Species-specific records are known to exist in commercial fishing companies. Future research into these data sources could be very valuable.

8.4.3. Data requirements for assessment of vulnerability and conservation status The issue of elasmobranch by-catch is of global concern and there are limited data available to assess the extent of the problem. The great diversity of elasmobranchs present in Community waters or taken by Community fisheries suggests that some research is required into their relative abundances and vulnerabilities. Many of these species are not target, but rather by-catch or discards. The sustainability of this elasmobranch by-catch is an important issue for Community fisheries policy, however there is little biological or historical information available to assess their sustainability through traditional stock assessment. The data required for such species are probably not applicable to the Sampling Programme. One approach that can be used to provide the data required for assessing their vulnerability and status is that outlined by Stobutzki et al. (2002), in a programme being applied by the Federal government of Australia.

The approach is considered a cost effective means to assess vulnerability of all elasmobranch species taken in a very wide range of different fisheries around Australia, and a similar approach could be taken for European waters. The sorts of data required are basic life-history data, as discussed in Chapter 3. Such an approach is particularly valuable where species diversity is high. In Community waters, greatest elasmobranch species diversity is in deep waters, but the data requirements for shelf- dwelling species are the same. Existing survey and observer programmes could provide means of sampling.

There is urgent need for a user-friendly fishermen’s identification guide for elasmobranchs in European waters, including the Mediterranean (130 species). Such a publication would be a valuable, cost effective and popular means to support better data collection for all Community elasmobranchs.

9. Management 9.1. Towards A Community Response to the FAO Plan of Action

9.1.1. Introduction The Commission is obliged to prepare a Plan of Action on the conservation and management of elasmobranchs in the framework of the FAO-IPOA sharks. This subsection outlines the background of international conventions of relevance to conservation of elasmobranchs (Fowler, 1999), in addition to an outline of the IPOA itself.

9.1.2. Main international conventions relevant for elasmobranchs The management of elasmobranch populations under a European Plan of Action should incorporate broader issues than the sustainable management of fisheries if it is to fulfill the aims of a Shark Plan as defined in the FAO IPOA-Sharks, which also requires shark fishing states to undertake the following actions:

* Identify and provide special attention, in particular to vulnerable or threatened shark stocks.

* Contribute to the protection of biodiversity and ecosystem structure and function.

Some ‘flagship’ species of elasmobranchs are already receiving various levels of legal protection following their addition to the relevant appendices of international wildlife and environmental conventions and national legislation. By providing a framework for such biodiversity actions, the European Shark Action Plan will assist the EU and its Member States to fulfill their obligations under a range of other legal instruments and conventions, particularly those concerned with elasmobranchs as elements of marine biodiversity or wildlife.

9.1.2.1. Biodiversity Convention (CBD) 1992 Over 150 States are Party to this Convention, agreed during the 1992 United Nations Conference on Environment and Development (UNCED or ‘Rio Earth Summit’). The CBD aims to conserve biological diversity and promote the sustainable, fair, and equitable use of its benefits. Parties are required to develop or adopt national strategies for the conservation and sustainable use of biological diversity in accordance with the CBD, to monitor components of biological diversity that are important for conservation, and to identify and monitor activities with likely adverse impacts on the conservation and sustainable use of biodiversity.

Fisheries issues, including the deteriorating status of fisheries and fish populations (particularly highly migratory species and populations not confined to EEZs) were debated at UNCED, leading to a conference to resolve the pressing management and conservation issues associated with highly migratory and straddling fish populations,

and to the adoption of the UN Fish Stocks Convention (see below). Further, the 1995 meeting of the CBD Conference of Parties adopted the Jakarta Mandate on Marine and Coastal Biodiversity that calls upon Parties to take action for the sustainable use of marine and coastal living resources.

The Biodiversity Convention is implemented in the European Union largely through the European Habitats Directive (Council Directive 92/43/EEC on the conservation of natural habitats and of wild fauna and flora), which does not explicitly cover any species of elasmobranchs, and by individual State legislation and other actions. For example, the UK responded to the CBD by preparing a Biodiversity Report listing many species of conservation concern, including basking shark Cetorhinus maximus, tope Galeorhinus galeus, porbeagle Lamna nasus and blue shark Prionace glauca, and subsequently developing Biodiversity Action Plans for ‘Commercial marine fish’, ‘Deep-water fish’, ‘Common skate Dipturus batis’ and ‘Basking shark’. These Action Plans contain measurable targets for improving conservation efforts directed at priority fish species and habitats.

Member States may propose Chondrichthyan fish species of particular conservation concern for protection in the European Union during future revisions of the appendices of the European Habitats Directive. Indeed, those species already listed on the Bern Convention (see below) could be transferred to the appropriate lists on the Habitats Directive should the Community’s reservation be lifted. In addition additional candidate species could be listed.

9.1.2.2. Convention on International Trade in Endangered Species (CITES) CITES came into force in 1975, and by late 1997 included 142 countries as party to the Convention. The Convention was established to protect species of wild fauna and flora from over-exploitation through international trade. Appendix I of CITES lists those species that are threatened with extinction and for which no international trade is allowed (except under exceptional circumstances). Trade in Appendix II species is subject to strict regulation and monitoring to ensure that it is not detrimental to the status of the listed species. CITES is now widely accepted by a large number of States as the world convention covering international trade in wild species, and several other conventions (e.g. Berne Convention and the ASEAN Agreement) no longer cover this role.

In 1994 the 9th Conference of the Parties (CoP) to CITES adopted a Resolution on Trade in Sharks and Shark Products. This expressed concern that some shark species are heavily utilised, that levels of exploitation in some cases are unsustainable and may be detrimental to the survival of certain species, that sharks were not specifically managed or conserved by any multilateral or regional agreement, and that international trade in shark products lacked adequate monitoring and control. The Resolution requested, inter alia, FAO and other international fisheries management organisations to establish programmes to provide biological and trade data in co- operation with all nations utilising and trading in sharks, and to assist States to collect species-specific data.

The 10th CoP adopted a number of CITES Decisions, arising from activities undertaken under Conf. Res. 9.17, directed to Parties, FAO, the CITES Secretariat and the CITES Animals Committee. This led, in due course, to the adoption by FAO in 1999 of the International Plan of Action for the Conservation and Management of Sharks (IPOA-Sharks). The IPOA-Sharks calls upon all States to produce a Shark Assessment Report (SAR) and, if they have shark fisheries, to develop and implement National Plans of Action (NPOA) by early 2001. Assessments of NPOA implementation should be undertaken in 2005 and every 4 years thereafter.

The CITES Animals Committee has been monitoring the implementation of the IPOA-Sharks and has concluded that little progress has been made, with only a very limited number of Parties having implemented National Plans of Action. This is attributed largely to the voluntary nature of the IPOA-Sharks. Parties to CITES will be discussing the potential role for CITES in assisting FAO members in the implementation of the IPOA-Sharks, especially regarding international trade in sharks and parts and derivatives thereof, and other shark conservation and management issues at the 12th CoP in November 2002. Draft shark Resolutions and Decisions and proposals to list basking and whale sharks on Appendix II of CITES will also be debated.

9.1.2.3. Intermediate Ministerial Meeting on the Integration of Fisheries and Environmental Issues, 1997 At the Intermediate Ministerial Meeting on the Integration of Fisheries and Environmental Issues in Bergen, March 1997, Ministers recognised the desirability of an ecosystem approach to fisheries, environmental protection, conservation and management measures, and the need to further integrate fisheries and environmental policies to protect the environment and to ensure the sustainability of its fish stocks and associated fisheries. Ministers agreed that the fishing mortality rate (in the North Sea) should be reduced or controlled so that stocks are rebuilt to or maintained at a sustainable level, and competent authorities were therefore invited to consider the establishment of priorities for the elaboration of stock assessments and forecasts, or other appropriate stock indicators, for a number of named species or species groups, including sharks, skates and rays. As the international scientific organisation responsible for research and independent scientific advice on living marine resources and environment issues in the Northeast Atlantic, ICES had indicated that it would attempt to provide the necessary technical information to enable establishment of target and limit reference points, and to present stock assessments and forecasts or other appropriate stock indicators, for elasmobranchs within a ten-year time frame from initiation. In order to achieve this, the ICES Study Group on Elasmobranch Fishes developed the idea of a research project, which was fulfilled by the EU-funded DELASS project. (Developing Elasmobranch Stock Assessments, CFP99/055).

9.1.2.4. UN Agreement on Straddling Fish Stocks and Highly Migratory Fish Stocks The Fish Stocks Agreement, adopted 1995 and entered into force 2001, facilitates implementation of Articles 63 and 64 of the UN Convention on the Law of the Sea

(UNCLOS) relating to the conservation and management of straddling and high seas fish stocks and Highly Migratory Species listed in UNCLOS Annex I. It is complemented by the FAO Code of Conduct for Responsible Fisheries (which sets out principles and international standards of behaviour for responsible practices) and establishes rules and conservation measures for high seas fishery resources to protect marine biodiversity, monitor fishing levels and stocks, provide accurate reporting of and minimise by-catch and discards, and gather reliable, comprehensive scientific data as the basis for management decisions. It mandates a precautionary, risk-averse approach to the management of the relevant species when scientific uncertainty exists. The Agreement also directs States to pursue co-operation in relation to these species through appropriate sub-regional fishery management organisations or arrangements.

The following species of elasmobranch are listed on Annex I (Highly Migratory Species) of UNCLOS: “Oceanic sharks: Hexanchus griseus, Cetorhinus maximus, Family Alopiidae, Rhincodon typus, Family Carcharinidae, Family Sphyrnidae and Family Isurida” [the latter is not taxonomically correct and may refer to Family Lamnidae]. Other species and populations may qualify as a ‘straddling stock’ under Article 63(2) of the Convention, particularly in areas where jurisdiction has not been extended to the 200-mile limit. It is considered that, for these sharks, co-ordinated management and assessment of shared migratory populations would promote an understanding of the cumulative impacts of fishing effort on the status of shared populations.

9.1.2.5. Bonn Convention on the Conservation of Migratory Species of Wild Animals (CMS) CMS recognises the need for countries to cooperate in the conservation of animals that migrate across national boundaries or between areas of national jurisdiction and the high seas, if an effective response to threats operating throughout a species' range is to be made. It provides a framework within which Parties may adopt strict protection measures for migratory species that have been categorised as endangered (listed under Appendix I), or conclude Agreements for the conservation and management of migratory species that have an unfavourable conservation status (listed in Appendix II). These Agreements are open to accession by all Range States of the species concerned, not just CMS Parties, and may cover any species that would benefit significantly from international co-operation.

The 6th Conference of Parties (1999) listed whale shark on Appendix II (Species whose conservation status would benefit from the implementation of international co- operative Agreements) and called for co-operative actions for this species for the 2000-2002 biennium. The 2002 CoP considered proposals to list the white shark on Appendix II and I (the latter lists species threatened with extinction).

9.1.2.6. Barcelona Convention for the Protection of the Mediterranean Sea (1976) A Protocol concerning specially protected areas and biological diversity in the Mediterranean, signed in 1995, lists three elasmobranchs (white shark Carcharodon carcharias, basking shark Cetorhinus maximus, and giant devil ray Mobula mobular)

in Annex II, endangered or threatened species, which should receive full protection when the Convention is ratified. Malta was the only state to have provided legal protection for these species by 2002. Annex III of the Protocol: Species whose exploitation is regulated, lists shortfin mako Isurus oxyrinchus, porbeagle Lamna nasus, blue shark Prionace glauca, white skate Raja alba, and angelshark Squatina squatina. Malta is the only Mediterranean State to have implemented elasmobranch species listings on Appendix II of the Barcelona Convention, by providing full legal protection for the white shark, basking shark and giant devil ray.

9.1.2.7. Bern Convention on the Conservation of European Wildlife and Natural Habitats The Bern Convention was set up under the auspices of the Council of Europe, but its membership is not restricted to Member States. It aims ‘to conserve wild flora and fauna and their natural habitats, particular emphasis being given to endangered and vulnerable species’. Animal species listed in Appendix II must be strictly protected by the Parties, and the damage or destruction of their breeding sites be prohibited. Parties are also encouraged to prohibit the possession and sale of strictly protected species. Appendix III lists animal species whose exploitation must be regulated in order to keep their populations out of danger. Species protected under the Bern Convention should also be included under the European Habitats Directive (see section on the Convention for Biodiversity – CBD).

At the Bern Convention meeting in December 1997, several elasmobranchs were added, albeit within the Mediterranean Sea only. Two species are now listed on Appendix II (Strictly protected fauna): the basking shark Cetorhinus maximus (with an EU reservation), and the devil ray Mobula mobular. Five species are listed on Appendix III (which requires regulation of species populations to keep them out of danger). These are the mako shark Isurus oxyrinchus, porbeagle shark Lamna nasus, blue shark Prionace glauca, white skate Raja alba, and angel shark Squatina squatina. This brings the Bern Convention in line with the listings on the Barcelona Convention Protocol, with the exception of a listing for the white shark.

9.1.3. Aims of a shark plan as defined in the FAO IPOA- Sharks In the FAO IPOA-Sharks ten objectives are listed:

1. Ensure that shark catches from directed and non-directed fisheries are sustainable. 2. Assess threats to shark populations, determine and protect critical habitats and implement harvesting strategies consistent with the principles of biological sustainability and rational long-term economic use. 3. Identify and provide special attention, in particular to vulnerable or threatened shark stocks.

4. Improve and develop frameworks for establishing and coordinating effective consultation involving all stakeholders in research, management and educational initiatives within and between States. 5. Minimize unutilised incidental catches of sharks. 6. Contribute to the protection of biodiversity and ecosystem structure and function. 7. Minimize waste and discards from shark catches. 8. Encourage full use of dead sharks. 9. Facilitate improved species-specific catch and landings data and monitoring of shark catches. 10. Facilitate the identification and reporting of species-specific biological and trade data. The Technical Guidelines for the conservation and management of sharks (FAO 2000) identify four elements of the IPOA-Sharks:

• species conservation • biodiversity maintenance • habitat protection • management for sustainable use. For each of the objectives, a Plan of Action should produce Action Points for each of the four elements above, and each action should have a timescale identified (start/ reviews/ completion dates). Action Points must include biennial reports to FAO on progress and four-year reviews of the European Shark Assessment Report and Shark Action Plan.

In view of the considerable length of time necessary to move from the current position in Europe of largely unmanaged, depleted and threatened stocks, towards rebuilt, sustainably managed stocks and fisheries, the timetable for implementation of the FAO IPOA-Sharks must be far longer than the four year review process. The long life span and slow maturation of many sharks often means that the effects of fishing and of management will not be apparent until 15-20 years after initiation (Camhi et al. 1998). It is also important to recognise that the IPOA must be implemented in incremental steps.

The first priorities could be:

- to introduce basic precautionary fisheries and conservation management measures, based on existing knowledge of biology and other limited data available;

- to initiate a significantly improved programme of research, monitoring, data collation and analysis to inform future management measures (requiring a significantly improved research, monitoring and management capacity within Europe);

- to introduce and implement a continual process of reviews of data, research outputs and fisheries performance, in order to fine-tune future management decisions.

There have, until very recently, been no explicit national or regional sustainable management objectives and no concerted attempt to manage directed or by-catch fisheries in Europe. A few local initiatives are still at an early stage and may not yet be capable of allowing stocks to rebuild or of delivering sustainable management.

The recent TACs introduced for elasmobranchs in the North Sea have not been set with the objective of delivering specific management objectives for these species, rather with the objective of managing fishing activities. They are based solely on levels of former unmanaged and likely unsustainable catches, not through a process of stock assessment. Other examples are the quotas allowing Norwegian and Faeroese access to Community waters to fish some pelagic and deep-sea elasmobranchs.

The only apparently effective management actions currently underway for elasmobranchs are directed towards conservation management by legally protecting threatened species. These initiatives were generally introduced in recognition of stock depletion, and not with the objective of achieving sustainable fisheries.

The lack of research and monitoring activity targeted at elasmobranchs and the consequent lack of data on which to base assessments of threat, identity of critical habitats and production of recommendations for sustainable harvesting strategies currently make it almost impossible to deliver these aims in Europe. Section 8 presents the gaps in the current knowledge base.

The action point to minimize waste and discards from shark catches in article 7.2.2.(g) of the Code of Conduct for Responsible Fisheries, refers to the need to minimise pollution, waste, discards, catch by lost or abandoned gear, catch of non-target fish and non-fish species, and minimisation of impacts on associated and dependent species through the use of selective, environmentally-safe and cost-effective fishing gear and techniques. It is partly intended to discourage the practice of finning sharks – removing the fins and discarding the remainder of the fish at sea, but is obviously of much wider relevance to shark fisheries (both target and by-catch).

9.2. Management of elasmobranch fisheries With a few exceptions, exploitation of elasmobranch species in Community waters has been unregulated and new fisheries continue to develop without any management structure in place. The collection of biological information and data for use in assessments has lagged behind exploitation. Consequently, current assessments are often inconclusive and are imprecise. Many of the elasmobranch species are taken as by-catch in directed fisheries for other fish, or in multi-species fisheries, which may be difficult to regulate for individual species. The Commission intends to produce a draft response to the IPOA for elasmobranchs. For management of Community elasmobranch fisheries, certain considerations can be made. Management measures are classified as input controls, output controls, technical conservation measures and closures of fisheries.

Management schemes should be harmonised between the Community, other coastal jurisdictions and international waters areas, because of the very wide distributions of some elasmobranch species (blue shark forms a single stock in the whole North Atlantic). This is particularly relevant for pelagic sharks, where management measures should be developed at ICCAT, and perhaps other regional fisheries bodies in tropical areas. It is also of relevance in deepwater fisheries, where measures should be applied also in the NAFO and NEAFC regulatory areas and in CECAF. A range of measures is probably best applied, being tailored to the specificities of the various fisheries and the different areas.

9.2.1. Input controls Such measures include effort controls, licencing schemes, restrictions on effective effort by gear type. Measures to regulate effective effort include restrictions on hook number, soak time, gill net length, or hours trawled.

A days at sea scheme is not useful for static gears, as it would not regulate effective effort. Gillnet effort on elasmobranchs should be regulated by controls on soak time and net length. Similarly, controls on hook number and line size in longline fisheries could be beneficial. Controls of static gear effort may involve detailed planning and monitoring, but are likely to have considerable benefits. Such measures could apply to spurdog, ray and deepwater shark fisheries.

Restriction of effort in trawl fisheries can be carried out by restricting hours at sea.

A regulation of hours at sea may be useful for regulating mixed species trawl fisheries such as those targeting rays. Combined with a designated ports scheme, regulation of days at sea would be easy to implement.

Hours at sea schemes could also have benefit for regulation of fisheries where elasmobranchs are taken as a by-catch. An example of this is the mixed-species deepwater fisheries, where sharks are an important by-catch. Regulation of effort in deepwater fisheries may be a useful primary management measure since it is difficult to tailor output controls to such a diverse suite of species. This approach should be accompanied by a designated ports and satellite monitoring by VMS to regulate effort by depth.

Input controls can help to reduce effort across an entire fishery and can be useful to regulate discarding and impacts on the Community.

9.2.2. Output controls The main output controls are total allowable catches (TAC’s) either for single species or for multi-species assemblages.

Single species TAC’s are most useful for regulating clean target fisheries, where there is little by-catch. Such fisheries for elasmobranchs in Community waters include some for spurdog, porbeagle, blue shark and basking shark. The relationship between catch and fishing mortality is not always well understood, but it can be considered that TAC’s can have benefit for regulating clean elasmobranch fisheries.

A frequently cited disadvantage of TAC’s is that they encourage discarding and high- grading. However some elasmobranch species are likely to have high survival after being discarded (e.g. Scyliorhinus canicula), suggesting that in the case of shelf- dwelling elasmobranchs, dogfish for example, these issues may not be such a concern.

However for deepwater fisheries taking elasmobranchs discard mortality is likely to be close to 100%, so discarding and high-grading would be significant problems associated with TAC regulation. Greatest elasmobranch species diversity occurs in deep waters, and TAC regulation would do little to regulate fishing impacts on the broader elasmobranch community.

Misreporting may take place if TAC’s are applied. For straddling and highly migratory stocks, this could be a particular problem, catches may be misreported to international waters.

9.2.3. Technical conservation measures Technical measures can include mesh size regulations, landing sizes, closed areas, gear restrictions and areal restrictions.

Closed areas could have considerable utility for species that aggregate, particularly at spawning times, or that have discrete nursery grounds or habitats. A good example are certain ray species that have spawning areas in shallow waters, e.g. Raja clavata the thornback ray in the Thames estuary. Likewise, closure to fishing of areas that have been shown to have spawning areas for common skate Raja batis, could be the only effective management measure possible. These species are only examples, of a range of possible species. Surveys may provide data for such regulations.

Mesh-size regulations can be very efficient for regulating gill net fisheries (Walker et al. 2002). If the fishery is clean, for example the spurdog fishery, a maximum mesh size could be particularly useful to protect the spawning stock. If the objective is to protect the spawning stock, then a maximum mesh size regulation could be beneficial. It has been shown that fishing effort on southern sharks in Australia is best targeted at the juveniles, where natural mortality is higher (Prince, 2002). Allometric data can be used to determine the optimum maximum mesh size for such fisheries. Tangle nets mesh size and hanging ratio could be the subject of regulation, because these gears may not discriminate very well on the basis of size.

Minimum mesh-size in trawl fisheries is possibly not very useful, because of elasmobranchs’ large size. Mesh-size is of no benefit for regulating deepwater trawl fisheries.

Maximum landing size is a preferred management tool for many elasmobranchs, spurdog for example. This would protect the spawning stock, and along with maximum mesh size, could be easy to implement. Discard mortality in shelf elasmobranchs may be lower than in teleost species, possibly suggesting this as a positive measure for dogfish, rays, and pelagic sharks. If this leads to a large increase in effort on juveniles this would not work, however.

It is important to consider the relative efficiencies of different gear types for elasmobranchs, where several gears are used.

Gear restriction could be very relevant to protect spawning and nursery areas, or important habitats. For example a ban on trawling and dredging may be useful in management of ray fisheries, to spawning and nursery grounds for rays in some areas. If possible, closure of particular depth strata would be a useful means to protect particular deepwater elasmobranchs that have discrete bathymetric distributions.

A specific technical conservation measure is a ban on finning, to reduce the waste of edible biomass, limit effort on elasmobranchs and problems of not having accurate species-specific catch data. The Commission is bringing forward proposals on this matter. The Sub-group considers that the regulation should cover all chondrichthyans, except ray and skates, and result in a complete cessation of this practice. It might be necessary to ban the separate landings of carcasses and fins in the regulation.

9.2.4. Closure of fishery Closures could be temporary or permanent. The effectiveness of closures depends on enforcement. However enforcement of markets could be a useful approach. For discrete fisheries such as basking shark, such an approach can be used, and has been applied outside the Community, in the Isle of Man. If a fishery is shown to be below limit reference points or is in obvious danger this approach may be important.

9.3. Case studies in fisheries management The basking shark is strictly protected in British, Isle of Man and Guernsey territorial waters. British protection encompasses not only a prohibition on capture or possession of basking sharks, but also protection from harassment. The UK government is currently considering proposals for the protection of the angel shark Squatina squatina, common skate and other species of long-nosed skates in British territorial waters

In addition to their commercial value, rays are also of interest to recreational sea anglers (the income to local communities from sea angling is significant in some areas) and to wildlife conservation groups. R. batis, for example, is currently the subject of a UK Biodiversity Action Plan that aims to stablise refuge populations and, in the longer term, to encourage the recolonisation of the species’ former range by reducing fishing mortality. Fishery Managers face the challenge of identifying practical conservation measures that must be acceptable to the majority of stakeholders if they are to be effective. Options include:

Size restrictions. Minimum or maximum size, with options by species or sex, for application to parts (wings) or to whole fish; Restricted licensing of vessel effort or catch (quotas); Technical measures (e.g. mesh sizes, vessel size, gear type); Gear restrictions (e.g. by location or time); No take or limited take zones (e.g. no taking of female ray).

Several Sea Fisheries Committees in England and Wales (Southern, Kent and Essex, Cumbria and South Wales) have established regional fisheries conservation bylaws setting minimum landing sizes for skates and rays caught within areas under their jurisdiction (0-6 miles of baseline). In at least one of these districts, this measure arose following concern expressed by sports fishermen regarding the decline in large rays. In all cases, these sizes were set to protect immature rays and are given both for the complete fish, with the measurements taken from wing tip to wing tip (disc width), and for a single wing width, if the wings have been removed from the body prior to landing (as they usually are). The South Wales Sea Fisheries Committee introduced its bylaw in two stages: in 1997 a minimum landing size of 40 cm wingtip to wingtip (minimum part wing 20 cm); increased in 2000 to 45 cm (22 cm). Debate following the introduction of this management measure in South Wales led to the establishment of "The Welsh Rays Group", comprised of fishery managers, scientists, commercial fishermen, recreational anglers and conservation interests. A similar initiative is now proposed for adjoining waters in Southwest England.

Porbeagle (Lamna nasus)

Canada began to manage its porbeagle fishery by phasing out Faroese fishing effort in 1994, and introducing the Canadian Shark Management Plan in 1995. This initially defined a non-restrictive catch guideline of 1,500t, followed in 1997 by a TAC of 1000t. The industry has also contributed to management on a voluntary basis by attempting to avoid catching large females during the spring pupping period, closing the summer fishery in 1999 and 2000 to reserve quotas for the fall season, and by restricting the area fished in fall.

The 2000-2001 Shark Management Plan further restricted catches to a total of 1700t over a 2 year period (850 t/yr) pending collection of additional scientific information during an intensive research programme initiated in 1998. This research included on- board collection of detailed measurements and tissues by scientific staff and the measurement by the fishing industry of over 75% of all sharks landed between 1998 and 2000. Unpublished tagging data from former fisheries were also studied to analyse stock structure and migration patterns, and commercial and research catch rates (kg/hook and number/hook) reviewed. The study led to a hugely improved understanding of the biology and population dynamics of the porbeagle and the stock assessment reported by Campana et al. (2001). Natural mortality rates and recent fishing mortality rates were estimated, an age- and sex-structured population model developed, and biological reference points calculated. Current biomass was estimated as being 11-17% of virgin biomass and fully recruited F in 2000 was estimated as 0.26.

DFO (2001) concluded that the intrinsic rate of population growth in an unfished porbeagle population is 5-7%. The current porbeagle population is seriously depleted and will require a greatly reduced fishing mortality if recovery is to occur. Recovery will not be rapid in such a low productivity species. Fishing at F0.1=0.18 is unsustainable, and will result in stock collapse. Fishing at F=0.08 results in zero population growth, while a fishing mortality (F) of 0.04-0.05 should correspond to maximum sustainable yield (MSY) and is required if the population is to be allowed to recover. All estimates of recent fishing mortality (following introduction of management) were well above sustainable levels, ranging from 0.1 to 0.3, with the most

reliable around F=0.2. An annual catch of 200-250 t would correspond to fishing at about MSY and would allow population growth. Annual catches of about 400 t would not allow any population growth, nor leave room for error in the estimates. However, annual catch levels of about 1000t will be sustainable in the long term once the population has recovered.

10. Recommendations The subgroup agreed the following:

• The subgroup should meet again in the course of 2003 to update the information provided in this report.

• In National Programmes high priority should be given to establishment of market sampling and observer programmes to provide information on species compositions of catches and landings, where such information is missing.

• Improvements in the Sampling regulation will begin to yield results, only in the medium term.

• Detailed species-specific data on length, weight, sex, age, maturity, etc. should be collected. The selection of species for collection of such data, could be based on member states’ share of landings.

• There is a need to improve knowledge of species- and age-specific data on natural mortality, reproduction, gestation period, spawning areas, nurseries, etc.

• Data collection for pelagic and deepwater sharks caught in international waters should be improved, including a consideration of life-history stages that inhabit international waters.

• Species identification skills should be improved where possible.

• Taxonomic errors in the present guidelines for the Data Sampling Programme need to be corrected.

• There is an urgent need for a user-friendly fishermen’s identification guide for elasmobranchs in European waters, including the Mediterranean (130 species).

• Archive survey data should be further explored to construct time series of abundance and for use in biodiversity analyses.

• It should be explored if catch and effort data from commercial transactions could provide useful information.

• Data from existing surveys and observer programmes should be analyzed to provide information on vulnerability and stock status of less common elasmobranch species.

• The DELASS project has considerably improved our knowledge of elasmobranch assessment methodology in the NE Atlantic. However, the main impediment to further progress is the lack of data. To keep the momentum gained in this project, and taking the poor knowledge of elasmobranchs into account, a follow-up project, focusing on collection of the strictly-specified data, should be urgently considered.

• Biodiversity conservation, and the threatened status of rare species is an area of growing concern. More work focusing on these aspects, is needed to allow an evaluation of the ecosystem effects of fishing on these vulnerable species.

11. References Bjordal, A., and Lokkeborg, S. 1996. Longlining. London: Fishing News Books. Bonfil, R. (1994). Overview of world elasmobranch fisheries. FAO Fisheries Technical Paper 341 119 pp. Camhi, M., Fowler, S.L., Musick, J.A., Brautigam, A. and Fordham, S.V. 1998. Sharks and their Relatives – Ecology and Conservation. IUCN/SSC Shark Specialist Group. IUCN, Gland, Switzerland and Cambridge, UK. iv + 39 pp. Castro, J.I., Woodley, C.M., and Brudek, R.L. 1999. A preliminary evaluation of the status of shark species. FAO Fisheries Technical Paper. No. 380. Food and Agriculture Organisation of the United Nations, Rome. 72 pp. Clarke, M.W. 2000. Aspects of the biology of three exploited deepwater sharks Centrophorus squamosus, Centroscymnus coelolepis and Deania calceus (Elasmobranchii, Squalidae) from the continental slopes of the Rockall Trough and Porcupine Bank. Dublin: National University of Ireland. Unpublished Ph.D. Thesis. Clarke, M.W., Connolly, P.L and Bracken, J.J. 2001. Biology of exploited deepwater sharks west of Ireland and Scotland. NAFO SCR Document. 19 pp. Clarke, M., Borges, L., Officer, R. and Stokes, D. 2002a. Comparisons of trawl and longline catches of deepwater elasmobranchs west and north of Ireland. NAFO SCR Document. Clarke, M.W., P.L. Connolly, and J.J. Bracken, 2002b. Catch, discarding, age estimation, growth and maturity of the squalid shark Deania calceus west and north of Ireland. Fis. Res. 56: 139-153. Connolly, P. L., and Kelly, C. J. 1996. Catch and discards from experimental trawl and longline fishing in the deep water of the Rockall Trough. Journal of Fish Biology, 49 (Supplement A), 132-144. Connolly, P. L., Kelly, C. J., and Clarke, M. W. 1999. Long-line Survey of the eastern slopes of the Rockall Trough. Dublin: Marine Institute. Fisheries Leaflet, no. 180. DFO, 2001. Porbeagle shark in NAFO subareas 3-6. DFO Sci. Stock Status Rept. B3-09 (2001). Fahy, E. 1989. The spurdog Squalus acanthias (L) fishery in southwest Ireland. Irish Fisheries Investigations. Series B. 32. 22pp. FAO, 2000. An appraisal of the suitability of the CITES criteria for listing commercially- exploited aquatic species. FAO Fisheries Circular. No. 954. Rome, FAO. 2000. 66pp. Paper prepared for the Technical Consultation on the suitability of the CITES criteria for listing commercially-exploited aquatic species.

FAO. 2000a. Technical consultation on the suitability of the CITES criteria for listing commercially-exploited aquatic species. FAO Fisheries Report 629. FAO. 2001. A background analysis and framework for evaluating the status of commercially- exploited aquatic species in a CITES context. FI:SLC/2001/2. (Paper prepared for the Second Technical Consultation on the suitability of the CITES criteria for listing commercially-exploited aquatic species.) Fowler, S.L. 1999. The role of non-governmental organisations in the international conservation of elasmobranchs. In: Shotton, R. (ed.) Case Studies of the management of elasmobranch fisheries. FAO Fisheries Technical Paper, No. 378. Food and Agriculture Organisation of the United Nations, Rome. Vol 2. Gallagher, M., Nolan, C.P. and Jeal, F. 2002. Age, growth and maturity of the commercial ray species from the Irish Sea. NAFO SCR Document. Gauld, J.A. (1989). Records of porbeagles landed in Scotland, with observations on the biology, distribution and exploitation of the species. Scottish Fisheries Research Report 45, ISSN 0308 8022. 15 pp. Girard M., 2001. Distribution et reproduction de deux espèces de requins de grands fonds, les “sikis”, Centrophorus squamosus et Centroscymnus coelolepis, exploités dans l’Atlantique Nord-Est. Bull. Soc. Zool. Fr., 126(3) :291-298. Girard, M., and M. H. DuBuit , 1999. Reproductive biology of two deep-water sharks from the British Isles, Centroscymnus coelolepis and Centrophorus squamosus (Chondrichthyes: Squalidae). J. Mar. Biol. Ass. U.K. 79: 923−931. Girard, M., P. Lorance AND A. Biseau. 2000. Captures par unite d’effort des especes profindes du talus continental a l’ouest de iles britanniques. Cybium. 24(3): 97-104. Hammond, T.R., C. Darby, J.R. Ellis and M.G. Pawson, 2002. Bayesian assessment of NE Atlantic spurdog using a stock production model, with prior for intrinsic rate of increase set by demographic methods. NAFO Elasmobranch Symposium, Santiago de Compostela (Spain), Paper 3.7. Hareide, N.-R. 1995. Comparisons between longlining and trawling for deep water species - selectivity, fish behaviour, quality and catchability. In Proceedings of NATO Advanced Research Workshop on deep water fisheries of the north Atlantic slope, (ed, A. G. Hopper), pp. 227-234. Amsterdam: Kluwer Academic Publishers. Holden, M.J. 1965. The stocks of spurdogs (Squalus acanthias L.) in British waters and their migrations. Fisheries Investigations. London. Series 2, 25(8), 27 pp. Holden, 1968. The rational exploitation of the Scottish-Norwegian stock of spurdogs (Squalus acanthias L.) Fisheries Investigations. London. Series 2 24(4), 20 pp. Holden, M. J. 1972. The growth rates of Raja brachyura, R. clavata and R. montagui as determined from tagging data. Journal du Conseil International pour l’Exploration de la Mer, 34: 161–168. Holden, M. J. 1975. The fecundity of Raja clavata in British waters. Journal du Conseil International pour l’Exploration de la Mer, 36: 110–118. ICES, 1995. Report of the Study Group on Elasmobranch Fishes, 15-18 August 1995. ICES, Copenhagen, Denmark. ICES, 2000. Report of the Study Group on the Biology and Assessment of Deep-sea Fisheries Resources. ICES CM 2000/ACFM:8, 206 pp. ICES, 2001. Report of the Working Group on the Biology and Assessment of Deep-sea Fisheries Resources. ICES CM 2001/ ACFM: 8

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ICES, 2002a. Report of the Study Group on Elasmobranch Fishes, 6-10 May 2002. ICES CM 2002/G:08. ICES, 2002b. Working group on the Biology and Assessment of Deep-Sea Fisheries Resources (WGDEEP). ICES CM 2002/ACFM: 16. IUCN. 2000. IUCN Red List of Threatened Species. IUCN, Gland, Switzerland and Cambridge, UK. IUCN. (2001). IUCN Red List Categories and Criteria: Version 3.1. IUCN Species Survival Commission. IUCN, Gland, Switzerland and Cambridge, UK. ii + 30 pp. Jones, B. C., and Geen, G. H. 1977. Reproduction and embryonic development of Spiny Dogfish (Squalus acanthias) from the strait of Georgia, British Columbia. Journal of the Fisheries Research Board of Canada, 34, 1286-1292. Jørgensen, O. 1995. A comparison of deep water trawl and longline research fishery in the Davis strait. In Proceedings of NATO Advanced Research Workshop on deep water fisheries of the north Atlantic slope, (ed., A. G. Hopper), pp. 420. Amsterdam, Kluwer Academic Publishers. Pineiro, C. G., Casas, J.M. and Banon, R.. 2001. The deep water fisheries exploited by Spanish fleets in the Northeast Atlantic: a review of the current status. Fisheries Research, 51: 311-320. Prince, J.D. 2002. Gauntlet fisheries for elasmobranchs – the secret of sustainable shark fisheries. NAFO SCR Document. Smith, S.E., Au, D.W. and Snow, C. 1998. Intrinsic rebound potential of 26 species of Pacific sharks. Marine and Freshwater Research…xxxxx Walker, P.A. and Heessen, H.J.L. 1996. Long-term changes in ray populations in the North Sea. ICES Journal of Marine Science, 53, 1085 – 1093. Walker, P.A. and Hislop, J.R.G. 1998. Sensitive skates or resilient rays? Spatial and temporal shifts in ray species composition in the central and north-western North Sea between 1930 and the present day. ICES Journal of Marine Science, 55, 392-402. Walker, T.I. 1998. Can shark resources be harvested sustainably? A question revisited with a review of shark fisheries. Marine and Freshwater Research 49. Walker, T.I., Gason, A.S., Hudson, R.J. and Knuckey, R.J. 2002. Assessing the impacts of fisheries on biodiversity of sharks and other chondrichthyans in south-eastern Australia and Great Australian Bight. NAFO SCR Document. Wheeler, A. 1978. Key to the Fishes of Northern Europe. London: Warne Ltd. 380 pp.

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12. ANNEX - List of participants

Dr. Maurice Clarke Dr. Mário Rui Pinho Marine Institute University of the Azores Abbotstown Department of Oceanography and Dublin 15 Fisheries Republic of Ireland. PT-9900 Horta, Azores Tel: + 353 1 8228354 Portugal Fax: + 252 1 8205078 E-mail:[email protected] E mail: [email protected]

Guzman Diez Dr. Bernard Seret Departamento de Recursos Pesqueros Muséum national d'histoire naturelle Fundación AZTI Fundazioa Laboratoire d'Ichtyologie générale et Txatxarramendi Irla z/g appliquée 48360. Sukarrieta (Bizkaia) antenne IRD País Vasco 43, rue Cuvier Spain 74231 Paris cedex 05 E-mail:[email protected] France Tel.: +33 1.40.79.37.38 Dr. Ivone Maria Figueiredo Fax: +33 1.40.79.37.71 IPIMAR E-mail: [email protected] Av. Brasilia 1400 Lisboa Dr. Marino Vacchi Portugal Istituto Centrale per la Ricerca E-mail:[email protected] Scientifica e Tecnologica Applicata al Mare Sarah Fowler (ICRAM) Nature Bureau International via di Casalotti, 300 36 Kingfisher Court 00166 Rome Hambridge Road Italy Newbury tel: +39 06 61570457 Berkshire RG14 5SJ fax: +39 06 61561906 United Kingdom e-mail: [email protected] ; Tel: + 44 1635 550380 [email protected] Fax: + 44 1635 550230 E-mail:[email protected] Dr. M. Vinther Danish Institute for Fisheries Research Dr. Henk J.L. Heessen Charlottenlund Castle Netherlands Institute for Fisheries DK-2920 Charlottenlund Research RIVO Denmark P.O. Box 68 E-mail: [email protected] 1970 AB IJmuiden, The Netherlands Tel: +31 255 564 692 Fax: +31 255 564 644 E-mail: [email protected]

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