ICES WGEF Report 2005 ICES Advisory Committee on fishery Management ICES CM 2006/ACFM:03 Ref. G Report of the Working Group on Elasmobranch Fishes (WGEF) 14–21 June 2005 Lisbon, Portugal 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. 2006. Report of the Working Group on Elasmobranch Fishes (WGEF), 14–21 June 2005, Lisbon, Portugal. ICES CM 2006/ACFM:03. 232 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. © 2006 International Council for the Exploration of the Sea ICES WGEF Report 2005 | i Contents 1 Introduction ................................................................................................................................... 1 1.1 Terms of Reference ............................................................................................................... 1 1.2 Participants ............................................................................................................................ 1 1.3 Background............................................................................................................................ 1 1.4 Current projects of relevance to the WG ............................................................................... 2 1.4.1 Working Group on Fish Ecology.............................................................................. 2 1.4.2 International Symposium on Dogfish Management ................................................. 2 1.4.3 Theme Session on Elasmobranch Fisheries Science, 2005....................................... 3 1.4.4 Study Group on Age Length Structured Assessment Models................................... 3 1.4.5 International Bottom Trawl Survey Working Group................................................ 3 1.5 Commercial catch data .......................................................................................................... 3 1.6 Discards data for elasmobranch fishes................................................................................... 5 1.7 Methods used......................................................................................................................... 6 1.8 Ecosystem considerations...................................................................................................... 6 1.9 Recommendations .................................................................................................................7 2 Spurdog in the North East Atlantic............................................................................................ 10 2.1 The Fishery.......................................................................................................................... 10 2.2 Biological composition of the catch .................................................................................... 12 2.2.1 Catch in numbers .................................................................................................... 12 2.2.2 Quality of catch and biological data ....................................................................... 12 2.2.3 By-catch and discards information ......................................................................... 12 2.3 Fishery-independent information......................................................................................... 12 2.3.1 Groundfish surveys................................................................................................. 12 2.4 Mean length, weight, maturity and natural mortality-at-age ............................................... 13 2.5 Recruitment ......................................................................................................................... 13 2.6 Stock assessment ................................................................................................................. 13 2.6.1 Previous studies ...................................................................................................... 13 2.6.2 Data exploration and preliminary modelling .......................................................... 14 2.6.3 Stock assessment .................................................................................................... 15 2.7 Simulation of effects of maximum landing size regulations................................................ 15 2.7.1 Methods .................................................................................................................. 15 2.7.2 Results .................................................................................................................... 17 2.8 Reference points .................................................................................................................. 17 2.9 Quality of the assessment .................................................................................................... 17 2.10 Pupping and juvenile fishing area closures.......................................................................... 17 2.11 Management considerations ................................................................................................ 17 3 Deep-water sharks in the North East Atlantic (ICES Areas I–XIV)....................................... 30 3.1 The fishery........................................................................................................................... 31 3.1.1 Advice and management applicable to 2005 and 2006........................................... 31 3.1.2 The fishery.............................................................................................................. 31 3.2 Biological composition of the catch .................................................................................... 33 3.2.1 Quality of catch and biological data ....................................................................... 33 3.2.2 Length and age frequencies .................................................................................... 35 3.3 Fishery-independent information......................................................................................... 36 3.4 Catch per unit of effort ........................................................................................................36 ii | ICES WGEF 2005 Report 3.4.1 Discards .................................................................................................................. 39 3.5 Mean length, weight, maturity, natural mortality and recruitment ...................................... 40 3.5.1 Leaf scale gulper shark ........................................................................................... 40 3.5.2 Portuguese dogfish.................................................................................................. 41 3.6 Stock assessment ................................................................................................................. 41 3.6.1 Previous assessments of stock status ...................................................................... 41 3.7 Reference points .................................................................................................................. 42 3.8 Quality of the assessment .................................................................................................... 42 3.9 Management considerations ................................................................................................ 42 4 Other deepwater sharks from the northeast Atlantic (ICES Subareas IV–XIV) .................. 56 4.1 The fishery........................................................................................................................... 56 4.1.1 Advice and management applicable ....................................................................... 56 4.1.2 Description of the fishery ....................................................................................... 56 4.2 Biological composition of the catch .................................................................................... 57 4.3 Fishery-independent information......................................................................................... 59 4.4 Catch per unit of effort ........................................................................................................59 4.5 Discards ............................................................................................................................... 59 4.6 Mean length, weight, age, maturity, natural mortality......................................................... 59 4.7 Stock assessment ................................................................................................................. 59 4.8 Stock status.......................................................................................................................... 60 4.9 Reference points .................................................................................................................. 60 4.10 Quality of the assessment .................................................................................................... 60 4.11 Management considerations ...............................................................................................