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Bibliography of the Maurice Lamontagne Institute

Réjean DUFOUR

GIGUÈRE, N., P. NELLIS, G.H. TREMBLAY, M. GIANGIOPPI, H.-F. ELLEFSEN, A. MAGASSOUBA, S. COMTOIS, C. SAVENKOFF, R.DUFOUR, 2011. Risk assessment procedure : development of tools and application in the capelin spawning. Can. Tech. Rep. Fish. Aquat. Sci.,2947, 44 p .

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This pilot project is linked to current national work and applies the theoretical notions of a risk analysis in the context of a real situation: capelin conservation in the Estuary and Gulf of St. Lawrence. While phase I resulted in the identification and the formulation of the problem through the development of Pathways of Effects (PoE) models, phase II, presented in this report, focusses on the development of a proposed risk assessment procedure and associated tools to be applied. The procedure is composed of four types of analysis: analyses of predicted conditions, measured conditions, and desired conditions, and a comparative analysis of conditions. The human activities and stressors identified in PoE models that potentially affect the capelin spawning / larval retention area were used to develop and apply the tools. To do this, Gallix beach, located in the region of Sept-Îles (Quebec, Canada), was selected as the ecological unit of reference. The proposed risk assessment procedure contributed to the development of a tool to analyze the predicted conditions. To carry out the three remaining types of analysis, other avenues were explored. All in all, the second phase of the pilot project demonstrated that tools can be developed to be versatile, flexible, and to perform well when used in a real context. Lastly, the work confirmed that risk assessment within a risk analysis process can help decision makers define priorities and subsequently focus their efforts on the management and regulation of activities that have greater potential social, cultural, or economic impacts.

GIGUÈRE, N., L. PERREAULT, P. NELLIS, C. SAVENKOFF, F.BILODEAU, M. GIANGIOPPI, G.H. TREMBLAY, R. DUFOUR, S. COMTOIS, F. GRÉGOIRE, 2011. Pathways of effects (PoE) model development for capelin conservation as part of a risk analysis process. Can. Tech. Rep. Fish. Aquat. Sci., 2934, 78 p .

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The purpose of the first phase of this pilot project was to create Pathways of Effects (PoE) models for capelin conservation in the Estuary and Gulf of St. Lawrence as part of a risk analysis process. When conducting this type of analysis, the PoE is created during the identification and problem formulation phase, the goal being to identify the potential relationships that exist between human activities, the stressors generated, and their impacts on a component of the ecosystem, and consequently on the communities that depend on this component. This project is related to the current national work on risk analysis and applies the theoretical notions established in the earlier work in the context of a real situation. In this context, capelin conservation in the Estuary and Gulf of St. Lawrence was identified for this project, since capelin is a key species in the marine food chain. During this phase, six PoE models were developed, each illustrating one view of capelin conservation that is either general or specific. Together, these models serve illustrate the relationships that exist between the ecological, socioeconomic, and cultural components as well as such key ecological parameters as the quantity and quality of capelin spawning / larval retention habitat and capelin abundance. The development and application of PoE models using a real situation have confirmed their usefulness as tools for integrating knowledge and for communication; PoEs also play a role in providing support for decision-making and guidance for subsequent steps in the risk analysis process.

GIGUÈRE, N., L. PERREAULT, P. NELLIS, C. SAVENKOFF, F. BILODEAU, M. GIANGIOPPI, G.H. TREMBLAY, R. DUFOUR, S. COMTOIS, F. GRÉGOIRE, 2011. Réalisation de modèles de séquence des effets (SdE) appliqués à la conservation du capelan dans le cadre d'une approche d'analyse de risque. Rapp. tech. can. sci. halieut. aquat., 2934, 83 p .

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The purpose of the first phase of this pilot project was to create Pathways of Effects (PoE) models for capelin conservation in the Estuary and Gulf of St. Lawrence as part of a risk analysis process. When conducting this type of analysis, the PoE is created during the identification and problem formulation phase, the goal being to identify the potential relationships that exist between human activities, the stressors generated, and their impacts on a component of the ecosystem, and consequently on the communities that depend on this component. This project is related to the current national work on risk analysis and applies the theoretical notions established in the earlier work in the context of a real situation. In this context, capelin conservation in the Estuary and Gulf of St. Lawrence was identified for this project, since capelin is a key species in the marine food chain. During this phase, six PoE models were developed, each illustrating one view of capelin conservation that is either general or specific. Together, these models serve illustrate the relationships that exist between the ecological, socioeconomic, and cultural components as well as such key ecological parameters as the quantity and quality of capelin spawning / larval retention habitat and capelin abundance. The development and application of PoE models using a real situation have confirmed their usefulness as tools for integrating knowledge and for communication; PoEs also play a role in providing support for decision-making and guidance for subsequent steps in the risk analysis process.

GIGUÈRE, N., P. NELLIS, G.H. TREMBLAY, M. GIANGIOPPI, H.-F. ELLEFSEN, A. MAGASSOUBA, S. COMTOIS, C. SAVENKOFF, R. DUFOUR, 2011. Démarche d’évaluation du risque : développement d’outils et application à la zone de fraie et d’alevinage du capelan. Rapp. tech. can. sci. halieut. aquat., 2947, 45 p .

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This pilot project is linked to current national work and applies the theoretical notions of a risk analysis in the context of a real situation: capelin conservation in the Estuary and Gulf of St. Lawrence. While phase I resulted in the identification and the formulation of the problem through the development of Pathways of Effects (PoE) models, phase II, presented in this report, focusses on the development of a proposed risk assessment procedure and associated tools to be applied. The procedure is composed of four types of analysis: analyses of predicted conditions, measured conditions, and desired conditions, and a comparative analysis of conditions. The human activities and stressors identified in PoE models that potentially affect the capelin spawning / larval retention area were used to develop and apply the tools. To do this, Gallix beach, located in the region of Sept-Îles (Quebec, Canada), was selected as the ecological unit of reference. The proposed risk assessment procedure contributed to the development of a tool to analyze the predicted conditions. To carry out the three remaining types of analysis, other avenues were explored. All in all, the second phase of the pilot project demonstrated that tools can be developed to be versatile, flexible, and to perform well when used in a real context. Lastly, the work confirmed that risk assessment within a risk analysis process can help decision makers define priorities and subsequently focus their efforts on the management and regulation of activities that have greater potential social, cultural, or economic impacts.

DUFOUR, R., H. BENOIT, M. CASTONGUAY, J. CHASSÉ, L. DEVINE, P. GALBRAITH, M. HARVEY, P. LAROUCHE, S. LESSARD, B. PETRIE, L. SAVARD, C. SAVENKOFF, L. ST-AMAND, M. STARR, 2010. 2010 Canadian marine ecosystem status and trends report. Advis. Sec. Sci. Advis. Rep. 2010/030(Revised), 38 p .

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DUFOUR, R., H. BENOIT, M. CASTONGUAY, J. CHASSÉ, L. DEVINE, P. GALBRAITH, M. HARVEY, P. LAROUCHE, S. LESSARD, B. PETRIE, L. SAVARD, C. SAVENKOFF, L. ST-AMAND, M. STARR, 2010. Rapport sur l'état et les tendances des écosystèmes marins canadiens en 2010. MPO, Secrétariat canadien de consultation scientifique, Avis scientifique, 2010/030(révisé), 43 p .

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DUFOUR, R., H. BENOIT, M. CASTONGUAY, J. CHASSÉ, L. DEVINE, P. GALBRAITH, M. HARVEY, P. LAROUCHE, S. LESSARD, B. PETRIE, L. SAVARD, C. SAVENKOFF, L. ST-AMAND, M. STARR, 2010. Ecosystem status and trends report: Estuary and Gulf of St. Lawrence ecozone. Rapport sur l’état et les tendances des écosystèmes : écozone de l’estuaire et du golfe du Saint Laurent. DFO, Canadian Science Advisory Secretariat, Research Document ; MPO, Secrétariat canadien de consultation scientifique, Document de recherche; 2010/030, 193 p .

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This document was produced under the umbrella of the national ecosystem status and trends report program and deal with the estuary and gulf of St.Lawrence ecozone. It is structured around the status and trends of some important marine species and physico-chemical variables of the ecosystem. The national ecosystem status and trends report will support prioruty-setting for a national biodiversity agenda and will integrate national and provincial exosystem-bases information. It will report on many large terrestrial and marine ecozones.

DUFOUR, R., M. GILBERT, M. LANTEIGNE, N. TEMPLEMAN, 2009. Objectifs de conservation pour les zones d'importance écologique et biologique (ZIEB) de l'estuaire et du golfe du Saint-Laurent. MPO, Secrétariat canadien de consultation scientifique, Avis scientifique, 2009/049, 10 p .

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DUFOUR, R., M. GILBERT, M. LANTEIGNE, N. TEMPLEMAN, 2009. Conservation objectives for the ecologically and biologically significant areas (EBSA) of the Estuary and Gulf of St. Lawrence. DFO, Canadian Science Advisory Secretariat, Science Advisory Report, 2009/049, 10 p .

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BOURGEOIS, M., R. DUFOUR, 2007. Zones d'importance écologique et biologique (ZIEB) de l'estuaire et du golfe du Saint-Laurent : identification et caractérisation. MPO, Secrétariat canadien de consultation scientifique, Avis scientifique, 2007/016, 15 p .

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DUFOUR, R., P. OUELLET, 2007. Estuary and Gulf of St. Lawrence marine ecosystem overview and assessment report. Can. Tech. Rep. Fish. Aquat. Sci., 2744E, 112 p .

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The report’s main objective is to provide a descriptive overview of the components, structure and functioning of the Estuary and Gulf of St. Lawrence ecosystem as well as a preliminary evaluation of the main pressures exerted by human activities at the ecosystem level. In doing so, the report identifies species/populations and geo-graphical areas, including marine coastal areas, that are either significant at the ecosystem level and/or of concern regarding the threat and impacts of human pressure on the Estuary and Gulf of St. Lawrence ecosystem.

DUFOUR, R., P. OUELLET, 2007. Rapport d'aperçu et d'évaluation de l'écosystème marin de l'estuaire et du golfe du Saint-Laurent. Rapp. tech. can. sci. halieut. aquat., 2744F, 123 p .

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The report’s main objective is to provide a descriptive overview of the components, structure and functioning of the Estuary and Gulf of St. Lawrence ecosystem, as well as a preliminary evaluation of the main pressures exerted by human activities at the ecosystem level. In doing so, the report identifies species/populations and geographical areas, including marine coastal areas, which are either significant at the ecosystem level and/or of concern regarding the threat and impacts of human pressure on the Estuary and Gulf of St. Lawrence ecosystem.

BOURGEOIS, M., R. DUFOUR, 2007. Ecologically and biologically significant areas (EBSA) in the Estuary and Gulf of St. Lawrence : identification and characterization. DFO, Canadian Science Advisory Secretariat, Science Advisory Report, 2007/016, 14 p .

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SAINTE-MARIE, B., R. DUFOUR, L. BOURASSA, D. CHABOT, M. DIONNE, D. GILBERT, A. RONDEAU, J.-M. SÉVIGNY, 2005. Critères et proposition pour une définition des unités de production du crabe des neiges (Chionoecetes opilio) dans l'estuaire et le nord du golfe du Saint-Laurent ; Criteria and proposition for the definition of snow crab (Chionoecetes opilio) production units in the estuary and northern Gulf of St. Lawrence. MPO, Secrétariat canadien de consultation scientifique, Document de recherche ; DFO, Canadian Science Advisory Secretariat, Research Document, 2005/059, 20 p .

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The current borders of snow crab management areas in the Department of Fisheries and Oceans (DFO) Québec region are not based on biological or oceanographical criteria and some times enclose territories with very different characteristics. As noted by the FRCC (2005), there is a need to define biological production units to better monitor the status and ensure conservation of populations. Toward that goal, we conducted a literature review and used trawl data from the Gulf of Saint Lawrence to identify the biological and physical factors that constrain the distribution and dispersal of snow crab. This information allows us to characterize snow crab habitat, which can be defined as a territory with bottoms of soft sediments, bathed by waters with a salinity > 26 ‰, part of which is at a temperature of 0-2 °C and the remainder at a temperature varying from about -1.5 to 4 °C. The surface waters above this territory must generally have a salinity > 26 ‰ and warm up to 5-15 °C for several weeks for larvae to survive and grow. Snow crab larvae can disperse themselves over long distances and this may explain the weak genetic differentiation of populations within the Gulf. However, the various benthic stages generally have a much smaller dispersal capability. We describe the criteria used to define biological production units and on that basis we propose to divide the territory under the responsibility of DFO-Québec into seven units.

DUFOUR, R., 2005. Crabe des neiges de l'estuaire et du nord du golfe du Saint-Laurent (zones 13 à 17 et 12A, 12B et 12C). MPO, Secrétariat canadien de consultation scientifique, Avis scientifique, 2005/027, 21 p .

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DUFOUR, R., 2005. Snow crab of the Estuary and northern Gulf of St. Lawrence (areas 13 to 17 and 12A, 12B and 12C). DFO, Canadian Science Advisory Secretariat, Science Advisory Report, 2005/027, 21 p .

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DUFOUR, R., 2004. Snow Crab of the Estuary and Northern Gulf of St. Lawrence (areas 13 to 17 and 12A, 12B and 12C) in 2003. Science, Stock Status Report, 2004/024, 14 p .

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BOURDAGES, H., D. ARCHAMBAULT, B. MORIN, A. FRÉCHET, L. SAVARD, F. GRÉGOIRE, R. DUFOUR, 2004. Résultats préliminaires du relevé multidisciplinaire de poissons de fond et de crevette d'août 2004 dans le nord du golfe du Saint-Laurent ; Preliminary results from the groundfish and shrimp multidisciplinary survey from August 2004 in the northern Gulf of St. Lawrence. MPO, Secrétariat canadien de consultation scientifique, Document de recherche ; DFO, Canadian Science Advisory Secretariat, Research Document, 2004/112, 40 p .

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As a result of the delays in putting the CCGS Alfred Needler into operation, the August 2004 multidisciplinary groundfish and shrimp survey in the northern Gulf of St. Lawrence was conducted aboard the CCGS Teleost, which itself suffered major damage, delaying the start of the mission. The survey was conducted between August 15 and September 2, corresponding to a period that was just over half of the time initially planned. A total of 130 tows were made throughout the area, 95 % of which were successful. Summary findings for catch rates, catch rate distributions and size frequency distributions are presented for 14 species, including the 4 species targeted by the survey (cod, Greenland halibut, redfish and Northern shrimp). However, the 2004 findings are preliminary and must be considered as such until laboratory analyses and data validation have been completed. With the exception of data on the spatial distribution of catches, data obtained during this survey cannot be compared with data obtained during previous missions aboard the CCGS Alfred Needler until conversion indices for each species will be calculated using data obtained during comparative missions. Data gathered in 2004 on the catch distribution of the various species indicate a pattern similar to those observed in previous years aboard the CCGS Alfred Needler.

DUFOUR, R., 2004. Crabe des neiges de l’estuaire et du nord du golfe du Saint-Laurent (zones 13 à 17 et 12A, 12B et 12C) en 2003. Rapport sur l'état des stocks, 2004/024, 15 p .

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DUFOUR, R., B. SAINTE-MARIE, L. BOURASSA, 2003. Snow crab of the St. Lawrence estuary and the northern Gulf of St. Lawrence (Areas 13 to 17 and 12A, 12B and 12C) in 2002. Science, Stock Status Report, 2003/011, 24 p .

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DUFOUR, R., SAINTE-MARIE, B., BOURASSA, L., 2003. Crabe des neiges de l'estuaire et du nord du golfe Saint-Laurent (zones 13 a 17 et 12A, 12B et 12C) en 2002. Rapport sur l'état des stocks, 2003/011, 23 p .

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DUFOUR, R., J.-P. DALLAIRE, 2003. Le crabe des neiges de l'estuaire et du nord du golfe du Saint-Laurent : état des populations de 1999 à 2001 ; Status of snow crab populations in the St. Lawrence Estuary and the Northern Gulf of St. Lawrence from 1999 to 2001. MPO, Secrétariat canadien de consultation scientifique, Document de recherche ; DFO, Canadian Science Advisory Secretariat, Research Document, 2003/048, 60 p .

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This document reviews the status of the snow crab stocks in the estuary and northern Gulf of St. Lawrence from 1999 to 2001. It contains all biological and management information on snow crab that was used to produce the annual stock status reports for zones 13 to 17 for the above period. The last age class of the previous wave of recruitment was available to the fishery in 1994. Afterward, the less abundant age class groups caused a decrease in the commercial catch rates and exploitable biomass and an ageing of the population. The most recent wave of abundant age class groups (age classes 1988 - to 1992) began to recruit to the exploitable population in 1997 but its effect was not felt the same way in each of the areas. In the west (Area 17), the biomass strongly increased and the average size of the crabs caught decreased further to the arrival of the new recruitment. However, in the area 16, a decrease in growth and a premature terminal moult of a certain amount of the males was noticed so that the effect of the wave was not as pronounced as in Area 17. These effects would have been more marked in the eastern sectors (Areas 15 to 13), where the wave is not still perceptible in the fishery. Indeed, the recruitment in those areas is weak and does not allow an increase of the exploitable biomass. The difference in productivity combined with an intense exploitation in the east lead to a very critical situation and the conservation of the resource is compromised.

DUFOUR, R., 2002. Snow crab of the estuary and northern Gulf of St. Lawrence (Areas 13 to 17). Science, Stock Status Report, C4-01, 13 p .

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DUFOUR, R., 2002. Crabe des neiges de l'estuaire et du nord du golfe du Saint-Laurent (zones 13 à 17). Rapport sur l'état des stocks, C4-01, 14 p .

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DUFOUR, R., 2002. DFO Quebec Region : estuary and north Gulf of Saint Lawrence snow crab stock assessment : a case example. Pages 11-13 in J.K. Rice & J. Moores (ed.). Zonal snow crab workshop ; atelier zonal sur le crabe des neiges (DFO, CSAS, Proceedings Series ; MPO, Secrétariat canadien de consultation scientifique, Série des comptes rendus, 2002/022) .

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DUFOUR, R., B. SAINTE-MARIE, 2001. Crabe des neiges de l'estuaire et du nord du golfe du Saint-Laurent (zones 13 à 17). Rapport sur l'état des stocks, C4-01, 16 p .

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DUFOUR, R., B. SAINTE-MARIE, 2001. Snow crab of the estuary and northern Gulf of St. Lawrence (areas 13 to 17). Science, Stock Status Report, C4-01, 15 p .

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DUFOUR, R., B. SAINTE-MARIE, 2000. Crabe des neiges de l'estuaire et du nord du golfe Saint-Laurent (zones 13 à 17). Rapport sur l'état des stocks, C4-01, 14 p .

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BOURASSA, L., R. DUFOUR, 2000. La remise à l'eau des crabes des neiges (Chionoecetes opilio) adolescents durant la pêche : description et essais de la méthode utiliseé. Rapp. can. ind. sci. halieut. aquat., 257, 38 p .

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Discard of the adolescent male snow crab of commercial size during the fishing operations increase their chance to moult again, which considerably increases their size and their meat weight. Furthermore, it allows them to be able to mate again the next spring and contribute to the perpetuity of the population. A crab of bigger size and beautiful appearance generally brings back a better price at landings and represents therefore a gain for the fishermen and the industry. Adolescent males can be identified visually after an adequate training. The adolescent males, so called "crabs with small claws", are distinguished from adult males, "crabs with bigger claws", by the size and the shape of their claws which are smaller and more lengthened. To accustom the fishermen to identify these quickly during sorting at sea, we suggest the use of a gauge as tool for learning. This gauge allows a fast identification of the adolescent crabs of commercial size between 95 and about 100 mm CW, the range of sizes where they are present in high numbers during the fishing operations. This measure of protection of the adolescent snow crabs of commercial size was applied successfully from 1997 until 1999 in the exploratory fishing zones A and B of the Gulf of Saint Lawrence. This pilot project received a positive answer from the fishermen of the zones concerned. Fishermen found the current gauge easy to use and very useful for the identification and sorting of adolescent males. Results showed that the use of the gauge did not cause delays in the sorting operations, or any visible increase of the mortality of crabs during these manipulations. The fishermen generally agreed that discard of the male adolescents should be implemented on a voluntary basis during the fishing operations.

DUFOUR, R., B. SAINTE-MARIE, 2000. Snow crab of the estuary and northern Gulf of St. Lawrence (areas 13 to 17). Science, Stock Status Report, C4-01, 13 p .

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DUFOUR, R., B. SAINTE-MARIE, 1999. Crabe des neiges de l'estuaire et du nord du golfe du Saint-Laurent (zones 13 à 17). Rapport sur l'état des stocks, C4-01, 14 p .

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DUFOUR, R., B. SAINTE-MARIE, 1999. Snow crab of the estuary and northern Gulf of St. Lawrence (Areas 13 to 17). Science, Stock Status Report, C4-01, 14 p .

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DUFOUR, R., J.-P. DALLAIRE, 1999. Le crabe des neiges de l'estuaire et du nord du golfe du Saint-Laurent : état des populations de 1995 à 1998. MPO, Secrétariat canadien pour l'évaluation des stocks, Document de recherche, 99/19, 46 p .

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This document reviews the status of the snow crab stocks of the estuary and northern Gulf of St. Lawrence from 1995 to 1998. It contains all biological and management data on snow crab that was used to produce the annual stock status reports for snow crab in this territory for the above period. The years 1995 to 1998 were an important period in the evolution of snow crab stocks in the estuary and northern Gulf. Research carried out in the 1990s revealed that recruitment of these stocks varies over an intrinsic cycle of approximately eight years during which 3 year-classes of low abundance (recruitment low) follow 5 year-classes of moderate to high abundance (recruitment wave). Thus, a recruitment low composed of the 1985 to 1987 year-classes entered the fishery of 1995 to 1997 and was followed by the first year-class (1988) of the 1998-2002 recruitment wave. The fluctuations in recruitment, and thus in the commercial biomass of available crab, had significant repercussions on the fishery, specifically a decline in catches and yields. The impact of the recruitment low followed by an initial year of the next recruitment wave was not felt uniformly throughout the territory. The effects of the recruitment low of 1995 to 1997 (decline in yields, stabilization or decrease in size and aging of commercial crab) and the beginning of the recruitment wave in 1998 (stabilization or increase in yields and size of commercial crab and end of aging) were more apparent in the western part of the territory (Area 17 and west of Area 16) than in the eastern part (east of Area 16 and Areas 15 to 13). The fishery was gradually adjusted during this period and catches declined by 23% throughout the territory until 1997, before picking up again in 1998 in the western sectors of the territory. However, given the significant fishing effort and the lack of data, the status of snow crab populations in sectors further east appears to be more critical and is of particular concern to us. Further research and ongoing cooperation between the fishing communities of these sectors and DFO will be required in order to obtain the data needed to gain a clearer understanding of the present and future condition of these stocks.

DUFOUR, R., 1998. Crabe épineux de l'estuaire et du golfe du Saint-Laurent. Rapport sur l'état des stocks, C4-04, 8 p .

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DUFOUR, R., 1998. St. Lawrence estuary and gulf northern stone crab. Science, Stock Status Report, C4-04, 7 p .

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DUFOUR, R., B. SAINTE-MARIE, 1998. Crabe des neiges de l'estuaire et du nord du golfe du Saint-Laurent (zones 13 à 17). Rapport sur l'état des stocks, C4-01, 15 p .

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DUFOUR, R., B. SAINTE-MARIE, 1998. Snow crab of the estuary and northern Gulf of St. Lawrence (areas 13 to 17). Science, Stock Status Report, C4-01, 13 p .

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DUFOUR, R., B. SAINTE-MARIE, 1997. Snow crab of the estuary and northern Gulf of St. Lawrence (areas 13 to 17). Science, Stock Status Report, C4-01, 19 p .

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DUFOUR, R., D. BERNIER, J.-C. BRÊTHES, 1997. Optimisation de la récolte de chair et mortalité durant les opérations de pêche au crabe des neiges (Chionoecetes opilio O. Fabricius) dans l'est canadien ; Optimization of meat yield and mortality during snow crab (Chionoecetes opilio O. Fabricius) fishing operations in eastern Canada. Rapp. tech. can. sci. halieut. aquat. ; Can. Tech. Rep. Fish. Aquat. Sci., 2152, 30 p .

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Changes in shell hardness and meat content were studied in the snow crab populations of the estuary and northern Gulf of St. Lawrence in 1990 and 1991. In parallel with this, an investigation on mortality of snow crab under fishing conditions approximating those of commercial fishing operations was conducted in 1991.

DUFOUR, R., B. SAINTE-MARIE, 1997. Crabe des neiges de l'estuaire et du nord du golfe du Saint-Laurent (zones 13 à 17). MPO, Pêches de l'Atlantique, Rapport sur l'état des stocks, C4-01, 20 p .

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DUFOUR, R., B. SAINTE-MARIE, 1996. Le crabe des neiges de l'estuaire et du nord du golfe du Saint-Laurent. MPO, Pêches de l'Atlantique, Rapport sur l'état des stocks, 96/6, 13 p .

DUFOUR, R., B. SAINTE-MARIE, 1996. Snow crab of the estuary and northern Gulf of St. Lawrence. DFO, Atlantic Fisheries, Stock Status Report, 96/6, 13 p .

SAINTE-MARIE, B., R. DUFOUR, 1995. Crabe des neiges de l'estuaire et du nord du golfe du Saint-Laurent (zones de pêche 13, 14, 15, 16 et 17). Pages 2-27 in L. Savard (éd.). Rapport sur l'état des invertébrés en 1994 : crustacés et mollusques des côtes du Québec, crevette nordique et zooplancton de l'estuaire et du golfe du Saint-Laurent. MPO (Rapp. manus. can. sci. halieut. aquat., 2323) .

DUFOUR, R., 1995. Le crabe des neiges de l'estuaire et du nord du golfe du Saint-Laurent : état des populations en 1994. MPO, Pêches de l'Atlantique, Document de recherche, 95/96, 61 p .

This document reviews the state of the snow crab populations in the Estuary and the northern Gulf of St. Lawrence. This fishery had its beginnings in the late 1960s, but did not experience major economic expansion until the late 1970s. Landings increased rapidly until 1985 and thereafter declined. After some difficult times in the industry in the late 1980s, catches are again on the rise; they reached record levels in 1994. Recent developments in the fishery and increased research into the snow crab of the Estuary and the northern Gulf have led to a better understanding of the phenomena underlying this exploitation. Several years of research on the North Shore since 1989 have resulted in a better understanding of the specie's life cycle. Periodic research surveys using a beam trawl in different regions of the northern Gulf have led, for the first time since the beginning of the fishery, to an overall, long-term understanding of the abundance fluctuations of the resource. Recruitment to the fishery follows an 8-year cycle : 5 years of average to high abundance (recruitment wave) follow 3 years of lower abundance (recruitment trough). The size structure in the peripheral fishing areas, such as the Lower North Shore, show a longer trough which can last up to 6 years in Area 13. This cycle could be generalized to all snow crab populations in the Gulf. Shorter-term recruitment indices, over 2 to 3 years, are under development and were the subject of a first joint project with the fishermen of the Middle North Shore in 1994. Thus a recruitment trough will affect the fishery starting in 1995 and will cause a major decrease in the performances of fishermen through the territory. The surveys show a decrease in recruitment and an increase in the proportion of adults with dirty shells on the bottom since 1992 in the West, and this phenomenon will intensify during the passage of the trough. Major problems due to massive entry of white crab into the catches can be expected, expecially toward the end of the recruitment trough in 1997, when the first 2 ages classes (1988-89) of the 1998-2002 recruitment wave will reach commercial size in the West. Subsequently, we expect large age classes to enter the fishery until 2002, before the fishery is affected by a new recruitment trough. The situation in the East is more precarious because of lower productivity and more sporadic recruitment to the population. The next important age classes will not reach the fishery until 1999 and 2001 in Area 15, and not until 2000 in Area 13. Also, the fishery begins later on the Lower North Shore and the fishermen take the recruits of the year, a certain number of which are adolescents which could still grow and reach a greater weight, in order to help offset the drop in numbers expected with the passage of the recruitment trough. The biomass of the commercial-sized crabs accumulated on the bottom is small, and exploitation rates would be higher than in the other regions because of smaller size at catch for quotas of similar weights. In one to two years' time, the industry should envision reducing quotas because of the passage of the 1985-87 recruitment trough. Two measures are suggested in order to lessen the consequences of the decline in the abundance of males during the recruitment trough and to maximize the yield per recruit : 1) Never land or injure adolescent males, because they are still growing and their weight will increase considerably over a period of one to two years. 2) Preferably land adult males with a dirty or intermediate shell, because they have completed their growth, and their quality and life expectancy diminish rapidly, making them less available for fishing.

SAINTE-MARIE, B., R. DUFOUR, 1995. Snow crab in the estuary and northern Gulf of St. Lawrence (fishing areas 13, 14, 15, 16 and 17). Pages 2-26 in L. Savard (ed.). Status report on invertebrates in 1994 : crustaceans and molluscs on the Québec coast, northern shrimp and zooplankton in the estuary and Gulf of St. Lawrence. DFO (Can. Manuscr. Rep. Fish. Aquat. Sci., 2323) .

SAINTE-MARIE, B., R. DUFOUR, 1994. Snow crab in the estuary and northern Gulf of St. Lawrence (fishing areas 13, 14, 15, 16 and 17). Pages 2-20 in L. Savard (ed.). Status report on invertebrates 1993 : crustaceans and molluscs on the Québec coast and northern shrimp in the Estuary and Gulf of St. Lawrence. DFO (Can. Manuscr. Rep. Fish. Aquat. Sci., 2257) .

DUFOUR, R., D. BERNIER, 1994. Potentiel d'exploitation du crabe des neiges, Chionoecetes opilio, et des crabes Hyas araneus et Hyas coarctatus dans le Nord de la péninsule gaspésienne. Rapp. tech. can. sci. halieut. aquat., 1996, 51 p .

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We investigated the potential for commercial exploitation of snow crab, Chionoecetes opilio, and of crabs Hyas araneus and Hyas coarctatus on the north shore of the Gaspé Peninsula. Biological information was also collected on H. araneus and H. coarctatus. The results are based on a 5 week fishing experiment conducted with Japanese traps in five sectors of the Gaspé Peninsula.

SAINTE-MARIE, B., R. DUFOUR, 1994. Crabe des neiges de l'estuaire et du nord du golfe du Saint-Laurent (zones de pêche 13, 14, 15, 16 et 17). Pages 2-23 in L. Savard (éd.). Rapport sur l'état des invertébrés en 1993 : crustacés et mollusques des côtes du Québec et crevette nordique de l'estuaire et du golfe du Saint-Laurent. MPO (Rapp. manus. can. sci. halieut. aquat., 2257) .

DUTIL, J.-D., J. MUNRO, R. DUFOUR, Y. GAUTHIER, F. HAZEL, B. SAINTE-MARIE, L. PROVENCHER, J. BOYER, D. HARDY, 1993. L'élevage du crabe des neiges : bilan des travaux de recherche. Ministère des pêches et des océans, Programme fédéral de développement des pêches du Québec, 12 p .

SAINTE-MARIE, B., V. LAPOINTE, D. ARCHAMBAULT, R. DUFOUR, 1992. Distribution spatiale et structure de taille du crabe des neiges, Chionoecetes opilio (O. Fabricius), dans le fjord du Saguenay. Rapp. manus. can. sci. halieut. aquat., 2156, 12 p .

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Exploratory fishing with baited traps was conducted in the Saguenay Fjord in July and August 1988 to determine whether or not Chionoecetes opilio occurred there and, if need be, to estimate the size of the population. The C. opilio in the Saguenay Fjord constitute a breeding population and there is local recruitment of juveniles. Mingling of individuals from C. opilio populations in the Fjord and in the Saint Lawrence Estuary may be limited by the 20-m deep external sill and by marked stratification of the water column. The population of C. opilio is apparently small and is in a quasi-virgin state.

DUFOUR, R., J.-C. BRÊTHES, 1992. Dynamique de la structure démographique du crabe des neiges (Chionoecetes opilio) sur la rive nord de l'estuaire maritime du Saint-Laurent et ses implications sur le recrutement à la pêche. Pages 43-52 in Y. De Lafontaine, T. Lambert, G.R. Lilly, W.D. McKone & R.J. Miller (éd.). Les stades juvéniles : le chaînon manquant en recherche sur les pêches. Ministère des pêches et des océans (Rapp. tech. can. sci. halieut. aquat., 1890) .

DUFOUR, R., J.-M. COUTU, 1990. État des stocks de crabe des neiges de l'estuaire et du nord du golfe du Saint-Laurent - Évaluation 1989. CSCPCA doc. rech., 90/37, 42 p .

In 1989, the fishery in areas 17 and 16 ended after 11 and 12 weeks respectively because of the poor quality of the captured crabs at the end of the season. The 1989 fishing season lasted only one week in Area 15 for similar reasons. The 1989 spring fishery previously planned in areas 13 and 14 was abandoned due to persisting ice conditions and weak catch rates. However, two fishing periods were allowed in the fall, from August to the end of September, and the season ended in 11 weeks. In addition to this change in areas 14 and 13, individual allocations were half the 1988 level and were set at 18.2 t in 1989. Total landings coming from these stocks have been declining since 1985, and the 1989 captures were 33 % less than that of the 1988 season, ending at 2580 t. The largest decrease, 84 %, came from areas 15, 14, and 13. The landings also diminished to a less extent in the other areas. On the southern shore of area 17, the 1989 mean catch rate calculated from Japanese traps, dropped slightly by 10 % from 1988, but the exploitation rate of 53 % stayed within the CAFSAC recommended threshold of 50 to 60 %. On the other hand, the mean arch rate dropped by 31 % from 1988 on the northern shore. The 1989 fishing season can be considered good in Area 16 compared to that of 1988. Although there was a high occurrence of white crab in June after three months of fishing, the catches were similar to that of 1988 and the mean catch rate per trap increased in all sectors of the area. The exploitation rates calculated in the area were below or within the recommended CAFSAC threshold. The catch rates obtained during the fall portion of the 1989 season showed encouraging signs for next year in most of the sectors. After major changes in their 1989 season and weak yield obtained thereafter, the areas 14 and 13 fishermen reoriented themselves toward other species such as cod in the Black Tickle area. Reasons for this unsuccessful fishing year may be multiple and diverse. The analysis of the fishery and research data showed a possible recruitment failure for 1988. As the 1989 fishing season was similar to that of 1988, we believe that the 1989 recruitment was also at a low level. However, the 1990 fishing season and that of subsequent years may improve substantially in area 13 if the influx of crab forecasted from the 1987-88 tagging surveys enter the fishery. Nevertheless, considering our present knowledge on the growth and the dynamics of this species, no precise long term prediction on the future stock catches can be obtained.

DUFOUR, R., R. BAILEY, 1990. Snow crab growth and stock size estimations obtained with coded wire tags in the St. Lawrence Estuary. Pages 505-516 in Proceedings of the International Symposium on King and Tanner Crabs, November 28-30, 1989, Alaska, USA . Alaska Sea Grant College Program, University of Alaska (Alaska Sea Grant Report, 90-04) .

DUFOUR, R., J.-M. COUTU, 1989. Crabe des neiges de l'estuaire et du nord du golfe du Saint-Laurent : évaluation 1988. CSCPCA doc. rech., 89/31, 51 p .

A preliminary estimate of total landings from the snow crab fishery in the Estuary and North Shore of the Gulf of St. Lawrence in 1988 shows a 31 % drop from 1987 levels. This sharp drop affected all zones, on a gradient sloping upward from west to east. In Zone 17, the 4 % decline from 1987 to 1988 may be explained by the appearance in June of large numbers of soft-shell crabs in the catches. Despite a recovery, or at least a halt in the decline, of the yield of Japanese traps on the south shore, yields on the north shore declined slightly in 1988, indicating a decline in production there. A reduction in fishing effort is recommended for Zone 17, through implementation of a preventive quota of less than 1000 t for 1989. In the western and central areas of Zone 16, the yields of Japanese traps are beginning to stabilize, while those of the eastern areas have been declining sharply since 1985, with no sign of recovery in 1988. Exploitation rates are high in the west (0.65) and east (0.68), and very high in Zone 15 (0.86). A major decrease in fishing pressure in Zone 15 and 16 would be desirable, and might possibly permit recovery of catch rates in the eastern part of Zone 16 and continuation of the recovery seen in the central and western areas of the zone. Implementation of a preventive quota lower than 1988 catches in Zones 15 and 15 is recommended. Although the biomass estimates calculated from tagging in 1987 and 1988 in Zone 13 show a bias that is unaccounted for, analysis of the rate of recapture of tags released in 1987 and recaptured in the same proportions in this zone in 1987 and 1988 (0.8 and 1.1 tags/10,000 crabs) indicate low recruitment to the commercial-sized crab stock between the two years. This would explain the sharp drop in catches recorded in 1988. Such as explanation is supported by analysis of the fishery statistics, which shows that the mean yield from the Japanese traps, which are mostly used in this zone, declined by half from 1987 to 1988. Also, the difference between the initial biomasses calculated in 1987 and 1988 by Leslie analysis (1326 t) corresponds quite well with the 1987 landings in the zone (1495 t). Many young male crabs under 75 cm were caught in Zone 13 and 14 during the 1988 tagging operation, pointing to a short-term recovery of the stock. In the meantime, a substantial reduction in fishing effort in the two zones would minimize the possible impact of overexploitation of these stocks.

DUFOUR, R., J.-M. COUTU, 1988. Stocks de crabe des neiges de l'estuaire et du nord du golfe du Saint-Laurent - Évaluation 1987. CSCPCA doc. rech., 88/35, 48 p .

DUFOUR, R., 1988. Overview of the distribution and movement of snow crab (Chionoecetes opilio). Pages 75-82 in G.S. Jamieson & W.D. McKone (ed.). Proceedings of the International Workshop on Snow Crab Biology, December 8-10, Montréal, Quebec. Dept. of Fisheries and Oceans (Can. Manuscr. Rep. Fish. Aquat. Sci., 2005) .

DUFOUR, R., 1988. Marquage du crabe des neiges du nord-est du golfe du Saint-Laurent en 1987. CSCPCA doc. rech., 88/39, 26 p .

SAINTE-MARIE, B., R. DUFOUR, C. DESJARDINS, 1988. Beaching of snow crabs (Chionoecetes opilio) on the north shore of the Gulf of Saint Lawrence. Naturaliste can., 115 :105-109 .

BAILEY, R.F.J., R. DUFOUR, 1987. Field use of an injected ferromagnetic tag on the snow crab (Chionoecetes opilio O. Fab.). J. Cons. Int. Explor. Mer, 43: 237-244 .

COULOMBE, F., R. DUFOUR, J.-L. BEAULIEU, 1986. Regard sur l'état des stocks de crabe des neiges, Chionoecetes opilio, de l'estuaire et de la Côte-Nord du Golfe du Saint-Laurent en 1983. CSCPCA doc. rech., 86/115, 31 p .

Snow crab catches in the Estuary and on the North Shore of the Gulf of St. Lawrence reached 3788 t in 1983, an increase of 25 % compared to 1982. This increase has been very strong on the Lower North Shore where catches have doubled from the previous year. There is also an increase in the global fishing effort concurrently with a spatial shift (partial) toward the sout shore in the Estuary and offshore at Rivière-au-Tonnerre on the Middle North Shore. On the whole, there is a net decrese in CPUE compared to previous years although the exploitation rates, as calculated by Leslie analysis, were closed to the target rates (50-60 %) recommanded by CAFSAC. Finally, there is no major changes in the size frequency distributions of snow crabs populations from the Estuary and the Middle North Shore in 1983.

DUFOUR, R., 1986. État des stocks de crabe des neiges de l'estuaire et du nord du golfe du Saint-Laurent en 1985. CSCPCA doc. rech., 86/16, 41 p .

Snow crab landings in the St. Lawrence Estuary and along the Quebec North Shore increased to 5 509 t. in 1985 (preliminary to 12-12-85). Compared with 1984, catches increased by about 70 % on the Lower North Shore (zones D and E) but decreased by 32 % in zone A and by 4 % in zones B and C. The fishery in zone A was closed for 11/2 month (from August to mid-September) due to a high proportion of white (soft shell) snow crab in the catch. Soft shell crab was also a possible cause of the decreased fishing activity, compared with 1984, in zone B during June and July. This soft shell problem made it impossible to use Leslie analyses for several areas and all of zone A. Analysis of tagging data for 1985 indicated an exploitation rate of 0.59 for the North Shore part of zone A. The estimated exploitation rates were at the target level of 0.5 to 0.6 in all other areas except in the Rivière-au-Tonnerre area where it was estimated to be 0.81. Average catch rates for all areas are similar to those calculated for 1984. Given the present exploitation rates, it is recommended that the effort should not be increased in any area. The adverse impact the molting period has on the fishery could be minimized by adjusting the fishing season.