ICES WGEF Report 2007 ICES Advisory Committee on Fishery Management ICES CM 2007/ACFM:27 REF. LRC Report of the Working Group on Elasmobranch Fishes (WGEF) 22–28 June 2007 Galway, Ireland International Council for the Exploration of the Sea Conseil International pour l’Exploration de la Mer H. C. Andersens Boulevard 44–46 DK-1553 Copenhagen V Denmark Telephone (+45) 33 38 67 00 Telefax (+45) 33 93 42 15 www.ices.dk [email protected] Recommended format for purposes of citation: ICES. 2007. Report of the Working Group Elasmobranch Fishes (WGEF), 22–28 June 2007, Galway, Ireland. ICES CM 2007/ACFM:27. 318 pp. For permission to reproduce material from this publication, please apply to the General Secretary. The document is a report of an Expert Group under the auspices of the International Council for the Exploration of the Sea and does not necessarily represent the views of the Council. © 2007 International Council for the Exploration of the Sea ICES WGEF Report 2007 | i Contents Executive Summary ......................................................................................................... 1 1 Introduction ............................................................................................................. 3 1.1 Terms of Reference ......................................................................................... 3 1.2 Participants ...................................................................................................... 6 1.3 Background...................................................................................................... 6 1.4 Future planning of the work of the group........................................................ 7 1.5 Current ICES Working Groups of relevance to the WG ................................. 9 1.5.1 Working Group on the Assessment of Demersal Stocks in the North Sea and Skagerrak (WGNSSK)................................................ 9 1.5.2 Working Group on the Assessment of Northern Shelf Demersal Stocks (WGNSDS) ............................................................................. 9 1.5.3 Working Group on the Assessment of Southern Shelf Demersal Stocks (WGSSDS).............................................................................. 9 1.5.4 Working Group on the Biology and Assessment of Deep-Sea Fisheries Resources (WGDEEP) ........................................................ 9 1.5.5 Working Group on Fish Ecology (WGFE)......................................... 9 1.5.6 International Bottom Trawl Survey Working Group (IBTSWG) ..... 10 1.5.7 Workshop on Taxonomic Quality Issues in the DATRAS Database (WKTQD) ......................................................................... 10 1.5.8 Stock Identification Methods Working Group (SIMWG) ................ 10 1.5.9 Planning Group on Commercial Catch, Discards and Biological Sampling (PGCCDBS) ..................................................................... 10 1.5.10 Workshop on using fishers to sample catches (WKUFS)................. 11 1.5.11 Study Group on Age-length Structured Assessment Models (SGASAM)....................................................................................... 11 1.5.12 Working Group on Fish Technology and Fish Behaviour (WGFTFB) ....................................................................................... 11 1.6 Other fisheries meetings of relevance to WGEF ........................................... 11 1.6.1 ICCAT .............................................................................................. 11 1.6.2 FAO .................................................................................................. 12 1.7 Nature conservation issues of relevance to the WG ...................................... 12 1.7.1 IUCN Redlist Process for the northeast Atlantic .............................. 12 1.7.2 Convention on International Trade in Endangered Species (CITES) ............................................................................................ 13 1.7.3 OSPAR ............................................................................................. 13 1.7.4 Shark Alliance .................................................................................. 13 1.8 Mixed fisheries advice for 2007 .................................................................... 13 1.9 Data availability............................................................................................. 14 1.9.1 Provision of data before working group ........................................... 14 1.9.2 Landings data.................................................................................... 14 1.9.3 Discards ............................................................................................ 15 1.9.4 Stock structure .................................................................................. 15 1.10 Methods and software.................................................................................... 15 1.10.1 Statistical modelling of survey data.................................................. 18 1.10.2 Demographic methods...................................................................... 21 1.10.3 Catch-free relative ASPM................................................................. 27 1.11 ICES Cooperative research report ................................................................. 27 ii | ICES WGEF Report 2007 1.12 Working documents presented ...................................................................... 27 1.13 References ..................................................................................................... 28 2 Spurdog in the North East Atlantic...................................................................... 31 2.1 Stock distribution........................................................................................... 31 2.2 The fishery..................................................................................................... 31 2.2.1 History of the fishery........................................................................ 31 2.2.2 The fishery in 2006........................................................................... 31 2.2.3 ICES advice applicable..................................................................... 31 2.2.4 Management applicable.................................................................... 31 2.3 Catch data ...................................................................................................... 32 2.3.1 Landings ........................................................................................... 32 2.3.2 Discards ............................................................................................ 32 2.3.3 Quality of the catch data ................................................................... 33 2.4 Commercial length frequencies ..................................................................... 33 2.4.1 Landings length compositions .......................................................... 33 2.4.2 Quality of data .................................................................................. 33 2.5 Commercial catch-effort data ........................................................................ 33 2.6 Research vessel surveys................................................................................. 33 2.6.1 Availability of survey data................................................................ 33 2.6.2 CPUE................................................................................................ 33 2.6.3 Length distributions.......................................................................... 34 2.7 Life-history information ................................................................................ 34 2.8 Exploratory assessment models..................................................................... 34 2.8.1 Previous assessments ........................................................................ 34 2.8.2 Simulation of effects of maximum landing length regulations......... 35 2.9 Quality of Assessments ................................................................................. 35 2.9.1 Catch data ......................................................................................... 35 2.9.2 Survey data ....................................................................................... 35 2.9.3 Biological information...................................................................... 35 2.10 Reference points ............................................................................................ 36 2.11 Management considerations .......................................................................... 36 2.12 References ..................................................................................................... 37 3 Deepwater “siki” sharks in the northeast Atlantic (IV–XIV)............................ 42 3.1 Stock distribution........................................................................................... 42 3.2 The fishery..................................................................................................... 42 3.2.1 History of the fishery........................................................................ 42 3.2.2 The fishery in 2006........................................................................... 42 3.2.3 ICES advice applicable..................................................................... 43 3.2.4 Management applicable...................................................................