Report of the Study Group on the Assessment of Shellfish Stocks in the North Atlantic

·-

Sbellfisb Committee ICES CM 1995/K:l Ref.: Assess

REPORT OF THE STUDY GROUP ON THE ASSESSMENT OF SHELLFISH STOCKS IN THE NORTH ATLANTIC

Tbis report is not to be quoted without prior consultation with the General Secretary. Tbe document is areport of an expert group under tbe auspices oftbe International Council for tbe Exploration of the Sea and does not necessarily rcprescnt the views ofthe Council.

International Council for the Exploration ofthc Sea Conseil International pour l'Exploration de la Mer

Palregade 2~ DK-1261 Copenhagen K Denmark 1

TABLE OF CONTENTS

Seetion Page

1 TERMS OF REFERENCE 1

2 RATIONALE FOR HOLDING THE STUDY GROUP 1

3 INFORMATION RECEIVED 1 3.1 Canada 2 3.2 Ieeland 2 3.3 Norway 2 3.4 Sweden 2 3.5 Denmark 2 3.6 Germany 2 3.7 United Kingdom 2 3.8 France 2 3.9 Spain 2

4 RECOMMENDATION 2 1 TERI\IS OF REFERENCE 2 RATIONALE FOR HOLDING THE STUDYGROUP Council Resolution 1994/2:47 states that the Study Group on the Assessment of Shellfish Stocks in the Although in the last decade the Shellfish Committee has North Atlantic "ill bc established under the co provided an increasingly successful forum for discussing chairmanship of a scientist from Canada and M.B. papers on shellfish biology and life history, and has Mesnil (prance) and ",11 meet in La Rochelle for four established Study Groups to update ICES on the days in June 1995 to: fisheries and fisheries biology ofCephalopods, Crangon, and Afajid crabs, the time has come for ICES to a) identify the needs and priorities for ad\ice on the establish its future role regarding the aSsessment and management of shellfish fisheries in the North management ofshellfish stocks. Atlantic; The main demersal and pelagic species are the b) review the data likely to bc available for assessing traditional preoccupation of managers and fisheries shellfish stocks; ministers, but the shellfishenes are of gro\\ing absolute and relative importance, and there are some fisheries, c) re\iew the available assessment methods, their Iikely such as those for Cephalopods, whieh are gro\\ing applicability to the different types of shellfish lire partieularly rapidly. Some coastal shellfish populations cycles, and the data required to apply them; are also subject to increasing threats from other coastal zone uses such as aggregate extraction, whose impact d) determine the future strategy for ICES shellfish needs to be assessed alongside the effccts offishing. assessments, including the terms of reference for a future meeting on this topic at thc Methods Working • Apart from the ongoing Working Group on Nephrops Group; stocks (and formcrly also Pandalus), however, ICES pro\idcs no ad\icc on thc management of shcllfish e) report to thc Shellfish Committee and ACFM. stocks to ACF1\f. This may be because many shcllfish spccics are predominantly coastal and are managed only Due to seriously conflicting work priorities for key on anational or local basis, but as a resuIt ICES has not membcrs it proved impossible to hold thc Study Group created the opportunity to rc\iew methodological and meeting as originally schcduled. Thc Chairman of thc anal)1ieal standards, or to debate management methods Consultative Committee, Dr R.C.A. Bannister (UK), and objectives, both "ithin the shellfish community and after consulting with the General Secretar)', decided to also between shellfish and finfish scientists, although postpone the Study Group meeting, but to solieit there was some dialogue between finfish and shellfish information on the shellfisheries in Member Countries scientists in the siock enhaneement context (Anon, by correspondence. This would go some way towards 1994). Shellfish species exhibit a variety of short and meeting the first term of reference, and would lay a long Iife histories, show interesting spatial patterns and factual foundation for a 1996 meeting of the Study metapopulation structures, and their distribution and Group. As a result of the correspondence round,. recruitment patterns may be strongly aITected by habitat, material was contributed by the follo\\ing countries: temperature, oceanographic, and predator/prey inßuences. Cephalopods, crabs, shrimps, and scallops, Canada Communicated by G. Ennis and also provide some cxamples of species whieh are of M. Moriyasu world "ide interest to biologists outside both the Denmark Communicated by P.S. Kristensen traditionalICES areas and the narrow interest of and S. Munch Petersen fishcries. France Communieated by D. Latrouite Against this background the chairmen of the Germany Communicated by Th. Neudecker Consultative Committee and ACFM feel that it is timely and bencficial to develop the ICES shellfish assessment Ice1and Communieated by U. SkUlad6ttir and management portfolio, cxpose it to peer revie\v and Norway Communieated by M. Aschen the rigour of the ACF1\1 approach to ghing ad\ice, but also to insinuate into finfish circles some awareness and Spain Communieated by I. Sobrino respect for the bcha\ioural and life history features Sweden Communieated by M. Ulmestrand characteristic ofshcllfish studies, and the nature oftheir management problems. The intention was that this UK(England Communieated by C. Bannister Study Groul> would be a starting point for the various and Wales) re\iews and discussions implied by this objective. UK ( Scotland) Communieated by N. DaHey

1 ,------,------

3 INFORMATION RECEIVED 3.7 United Kingdom

The correspondence round sought information on a fact Nephrops non'egicus, Cancer pagurus, Afaia squinado, sheet comprising questions about the number of species Palinurus elephas, Necora puber, Pandalus borealis, and stocks, type of data collected and parameters Crangon crangon, Pandalus montagui, Pecten maximus, measured, !)'pes of assessment, the nature of the Chlamys opercularis, Cerastoderma edule, Afytilus management regime, and the t)'pes of problems edulis, Littorina spp., Ostrea edulis, Buccinum outstanding. Returns have been archived for future use undatum, Loligo jorbesi, Illex sp., Sepia officinalis by the Study Group, for the species listed by country below, but unfortunately it has not been possible to 3.8 France publish the returns in detail in this report. Nephrops non'egicus, Cancer pagurus, lIfaia squinado, 3.1 Canada Palinurus elephas, Necora puber

llomarus americanus, Chionoecetes opilio, Pandalus 3.9 Spain borealis, Placopecten magellanicus, Chlamys islandica, Spisula polyayma, and green sea urchin Parapenaeus longirostris, Octopus vulgaris

3.2 Ieeland The above list is substantial, and gives an ovef\iew of the main species of interest to ICES countries, but it is Nephrops norvegicus, Pandalus borealis by no means complete. Additional useful information is contained in the Shellfish Commillee Report of 3.3 NonYa)' Acthities for 1991 (ICES CM 19921K:1).

Pandalus borealis, Paralithodes sp., Chlamys islandica 4 RECOMMENDATION 3.4 Sweden Noting that the incomplete nature of this report arises Nephrops norvegicus, llomarus gammarus, Pandalus because of an unexpected confiict of work demands in borealis 1995, the Shellfish Commillee and ACFM are inviled to recommend that the postponed meeting of this Study 3.5 Denmark Group should take place in 1996, under the same terms of reference, to pursue the original aims. Delegates are Nephrops norvegicus, Pandalus borealis, Afytilus edulis, invited to note the justification for the Study Group on Cerastoderma edule, Spisula solida page 1, and to pro\ide the national resources required for relevant experts to allend the 1996 meeting. 3.6 Germany

llomarus gammarus, Cancer pagurus, Crangon crangon, Afytilus edulis, Spisula solida