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Bibliography of the Maurice Lamontagne Institute

Sylvie BRULOTTE

BRULOTTE, S., 2011. Assessment of Softshell Clam stocks in Quebec's coastal waters in 2010. DFO, Canadian Science Advisory Secretariat, Science Advisory Report, 2011/022, 17 p .

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BRULOTTE, S., 2011. Évaluation des stocks de mye commune des eaux côtières du Québec en 2010. MPO, Secrétariat canadien de consultation scientifique, Avis scientifique, 2011/022, 18 P .

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BRULOTTE, S., 2011. Évaluation des stocks de mye commune des eaux côtières du Québec ; Assessment of softshell clam stocks of Québec's coastal waters. MPO, Secrétariat canadien de consultation scientifique, Document de recherche ; DFO, Canadian Science Advisory Secretariat, Research Document , 2011/044, 63 p .

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The Québec inshore waters softshell clam (Mya arenaria) stock status is determined primarily based on commercial fishery indicators. This document presents the methodologies and data that were presented during the peer review that took place in January 2011. Softshell clams are present almost everywhere along the shoreline of the Estuary and Gulf of St. Lawrence and Chaleurs Bay. Softshell clam harvesting is carried out almost exclusively with hand tools. Québec's maritime regions are divided into three management units: North Shore, Gaspé Peninsula – Lower St. Lawrence and the Îles-de-la-Madeleine. In recent decades, commercial harvesting has been practiced mainly on the Upper North Shore. There has been no commercial harvesting in the Gaspé and Lower St. Lawrence since 2006. Commercial landings in the Îles-de-la-Madeleine have totalled less than 1 t since 2005. Upper North Shore landings reached 1,173 t in 2000 and have been declining since. The harvesting effort dropped from 11,585 vendor-days in 2002 to 1,942 vendordays in 2009. The effort was even lower in 2010 due to the closure of two clam processing plants on the Upper North Shore. Catch per unit effort was generally low between 2006 and 2008 compared to the 2002-2005 values. The size structures of landed clams vary from one sector to another. From 2008 to 2010, median size ranged between 52 and 78 mm on the major sectors harvested with proportions of sub-legal size clams in the landings ranging between 1 and 21 %.

BRULOTTE, S., 2010. Assessment of Atlantic Surfclam in the coastal waters of the Îles-de-la-Madeleine in 2009. DFO, Canadian Science Advisory Secretariat, Science Advisory Report, 2010/016, 11 p .

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GIGUERE, M, S. BRULOTTE, N. PAILLE, 2010. Croissance et mortalité de trois stocks de pétoncle d’Islande (Chlamys islandica) mis en élevage à quelques sites de la Moyenne-Côte-Nord, Québec. Rapp. tech. can. sci. halieut. aquat., 2910, 67 p .

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Growth and mortality of Iceland scallops were evaluated in reciprocal transfers between three stocks and sites (AN, QU, CHS) of the Middle North Shore to which three sites were added (CM, HAS and CHN) for captive breeding surveys with the CHS stock. After a year of breeding in pearl nets, the mortality rate of scallops ranged from 4 to 60%, this variable was significantly influenced by the site and stock. The average shell growth ranged from 1.7 to 7.6 mm. The site significantly impacted the final size of the scallops, while the stock and the site notably influenced the weight of the meat and gonad. The results show that the transfer of scallops from beds where growth is weak to more proficient sites helps accelerate their growth. However, the magnitude of the mortality observed could reduce the biological and economic benefits of such intervention. Viii

BRULOTTE, S., B. THOMAS, H. BOURDAGES, M. GIGUERE, M. BOUDREAU, 2010. Captage de naissain de pétoncles sur la rive sud de la Gaspésie (Québec) de 1999 à 2004. Rapp. tech. can. sci. halieut. aquat., 2889, 117 p .

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Efforts have been deployed over the last decade to assess the breeding potential of sea scallops, Placopecten magellanicus, and Iceland scallops, Chlamys islandica, on the south shore of the Gaspé Peninsula. Results from the work performed between 1999 and 2004 concern scallop spat distribution and other related species between the Bay of Tracadigache and the Bay of Gaspé, their distribution in the water column and their available temporal window for collection. In addition, data was collected on the marine environment (temperature and salinity) and the sea scallop’s gonadosomatic development status. Stations were divided into three sectors: Bay of Tracadigache (8 stations), Bay of Gaspé (9 stations) and Centre (7 stations along the coast between Tracadigache and Gaspé). Spat collectors were submerged in late August, early September between 1999 and 2003. They were recovered after being submerged 3, 10, 12, 14 and 22 months. Results revealed that the spawning period for sea scallops appears to occur during the last two weeks of August in the Gaspé Peninsula. Sea and Iceland scallops were captured at every station sampled. Spat collection success for both scallop species was different from one station to another, but was not significantly different from one year to the next. Stations in the Bay of Tracadigache and the Bay of Gaspé had the highest number of captured scallops. The ratio between the abundance of the two scallop species varied based on the station and year. However, in many cases, sea scallops dominated in Tracadigache and sometimes in Gaspé. Spat abundance in the collectors decreased with their soak time. Significant attrition occurred in the Bay of Tracadigache between 3 and 10 months of soak time. A drop in the number of sea scallop specimens was also observed between 10 and 14 months of soak time in all sectors. These losses are likely the result of scallops releasing from the collectors and their predation. Furthermore, the intensity of the annual spat collection does not seem consistent with the depth of the collectors in the water column or with the thermocline, even if in some cases the trends observed appear to support this theory. The peak of settlement for spat scallops occurred at mid-October. Scallop growth varied according to the species, location and year. It was faster for sea scallops than Iceland scallops and faster in the Centre and Gaspé sectors than in Tracadigache. Fouling often covered the collectors, but their abundance fluctuated over time and based on the sector. A wide range of species was found in the collectors, around 40 taxa. The dominant species were Hiatella arctica, Mytilus spp. and hydrozoans. Predators, such as Asterias rubens, Cancer irroratus and Hyas spp. were observed in the collectors. Starfish were the most abundant predator. The available window for most of these species coincided with that of the scallops.

CHABOT, D., C. CYR, S. BRULOTTE, 2010. Compte rendu de la réunion du processus consultatif scientifique de la région du Québec portant sur l’examen du plan de suivi écologique de la ZPM Manicouagan. MPO, Secrétariat canadien de consultation scientifique, Série des comptes rendus; DFO, Canadian Science Advisory Secretariat, Proceedings Series, 2010/044, 20 p .

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BRULOTTE, S., 2010. Évaluation des stocks de la mactre de l'Atlantique des Îles-de-la-Madeleine en 2009. MPO, Secrétariat canadien de consultation scientifique, Avis scientifique, 2010/016, 12 p .

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BRULOTTE, S., 2009. Assessment of Quebec coastal waters whelk stocks in 2008. DFO, Canadian Science Advisory Secretariat, Science Advisory Report, 2009/028, 10 p .

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BRULOTTE, S., 2009. Évaluation des stocks de buccin des eaux côtières du Québec en 2008. MPO, Secrétariat canadien de consultation scientifique, Avis scientifique, 2009/028, 10 p .

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BOURASSA, L., S. BRULOTTE, 2009. Compte rendu de l'atelier sur les indicateurs de l'état des stocks de mye (Mya arenaria), 26 octobre 2004, Institut Maurice-Lamontagne, Mont-Joli, Qc ; Proceedings of the workshop on indicators of stock status of soft-shell clam (Mya arenaria). MPO, Secrétariat canadien de consultation scientifique, Série des comptes rendus ; DFO, Canadian Science Advisory Secretariat, Proceedings Series, 2009/057, 14 p .

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BOURASSA, L., M. GIGUÈRE, S. BRULOTTE, C. CYR, L. PERREAULT, 2008. Évaluation de la croissance, du taux d’exploitation et du recrutement à la pêche de la mactre de Stimpson (Mactromeris polynyma) de la Moyenne-Côte-Nord, Québec. Rapp. tech. can. sci. halieut. aquat., 2799, 49 p .

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In 2004 and 2005, there was work conducted in cooperation with the industry to acquire data on the growth rate of the Stimpson’s surfclam, to assess the resilience of local populations to high exploitation rates, and to estimate the species’ recruitment. Surveys were made on the Longue-Pointe-de-Mingan Stimpson’s surfclam natural bed using a grab sampler, a video camera and a hydraulic dredge. A tagging and recapture experiment was also conducted on two experimental parcels. Age estimates from growth lines on the chondrophore of the surfclam’s shell as well as growth datameasured from tagged individuals indicated that the Stimpson’s surfclam is a slow growth species. Based on our results, between 13-20 years would be required for reaching respective lengths of 80-100 mm. Average catches per unit of effort of surfclams (standardized per fishing hour and for a 1 m wide dredge) varied between 292 and 442 kg/h·m for two parcels and for both experimental years. The effort deployed during the experiments did not show any Stimpson’s surfclam depletion on the two Longue-Pointe-de-Mingan clam bed experimental parcels. The exploitation rate estimates for the tagging - recapture project during the 2004 directed fishery were respectively 11 % and 17 % on experimental parcels M-1 and M-2. However, different factors (e.g. mortality, vulnerability, loss of tag) were likely responsible for under estimating exploitation rates. The mean numbers per unit of effort (all sizes confounded) were 1,200 surfclams/h·m near parcel M-1 and 1,785 surfclams/h·m near parcel M-2 when a doubled dredge was used. Recruitment appears to be more homogeneous at the parcel scale (100-200 m) than in the scale separating the two experimental parcels (2.4 km). Results from the work carried out in 2004 and 2005 tend to show that knowledge acquisition concerning exploitation and Stimpson’s surfclam population dynamics is complex. The use of alternative methods, such as the grab sampler, the video camera and the dredge doubled with fine mesh, is necessary for better understanding the abundance of young urfclams and their habitat on the fishing ground. This information will help develop exploitation and conservation strategies that account for the low growth rate of this sedentary species.

GIGUÈRE, M., S. BRULOTTE, M. BOUDREAU, M.-F. DRÉAN, 2008. Évaluation de huit gisements de mye commune (Mya arenaria) de la rive nord de l’estuaire du Saint-Laurent de 2002 à 2008. Rapp. tech. can. sci. halieut. aquat., 2821, 101 p .

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Between 2002 and 2008, work was conducted on the shoreline of the Upper North Shore, between Tadoussac and Pointe-aux-Outardes, to describe the status of eight softshell clam (Mya arenaria) populations. The beds that were examined were, from west to east, Baie du Moulin à Baude, Baie des Petites Bergeronnes, Pointe à Émile, Baie des Chevaux, Cran à Gagnon, Anse Noire, Réserve Betsiamites Sud and Pointe-aux-Outardes. All these beds were located at the mouth of rivers or creeks. Sampling grids, which were systematic, were adjusted to account for the size and shape of the surveyed sites. The top of each grid was set at of the intertidal zone’s upper limit and its base at the level corresponding to the zero chart datum. The grid comprised between 20 and 173 stations depending on sites. A vacuum-type apparatus, providing a Venturi effect, was used to collect organisms when sediment was malleable and the water layer was more than 10 cm. Otherwise, a shovel was used. Organisms and sediment were collected over a 0.25 m2 area to a depth of 0.30 m. The results present altimetry, sediment, plant cover, benthic species present and dominant, as well as a few biological characteristics of the softshell clam populations. The dominant sediment was sandy silt at Pointe à Émile, Baie des Chevaux, Cran à Gagnon and Anse Noire, sand at Réserve Betsiamites Sud, sand and gravelly sand at Baie du Moulin à Baude and gravelly sand at Baie des Petites Bergeronnes and Pointe-aux-Outardes. There was little or no eelgrass (Zostera marina) at many of the inventoried sites. Macoma balthica was, along with softshell clams, the most common species, followed by polychaetes, Mytilus edulis and Mesodesma arctatum. The highest average densities, between 183 and 175 softshell clams/m2, were recorded respectively at Pointe à Émile and Baie des Chevaux. The lowest average densities, under 51 clams/m2, were recorded at Baie des Petites Bergeronnes, Pointe-aux-Outardes and Baie du Moulin à Baude. Maximum densities varied from 136 clams/m2 (Baie du Moulin à Baude) to 2,204 clams/m2 (Réserve Betsiamites Sud). The highest average densities of legal size softshell clams (10-27 clams/m2) were recorded at Baie du Moulin à Baude, Réserve Betsiamites Sud, Pointe-aux-Outardes, Baie des Petites Bergeronnes and Cran à Gagnon. For the other beds, values varied between 1.6 and 9.1 clams/m2. The maximum size of softshell clams harvested was larger at Réserve Betsiamites Sud (107 mm) and Pointe-aux-Outardes (102 mm) and smaller at Pointe à Émile (55 mm) and Anse Noire (60 mm). The results obtained indicated that legal size softshell clams were generally more abundant on sand and gravelly sand foreshores than on silty sand foreshores. The largest sizes are likely reached in sand and silty sand habitats. However, large sizes can also be reached in sandy silt such as at Baie des Chevaux and Cran à Gagnon. Comparing our results with other data from around 40 years ago showed that the condition of some of the beds has regressed, probably as a reaction to to the exploitation of these populations which has been intense at times.

MCQUINN, I., S. BRULOTTE, C. CYR, 2008. Évaluations des stocks de mollusques des eaux côtières du Québec en 2005, 17 et 26 janvier 2006, Institut Maurice-Lamontagne ; Stock Assessments on mollusks in Quebec coastal waters in 2005, January 17 and 26, 2006, Maurice Lamontagne Institute. MPO, Secrétariat canadien de consultation scientifique, Série des comptes rendus ; DFO, Canadian Science Advisory Secretariat, Proceedings Series, 2008/003, 20 p .

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This document contains the proceedings from the meetings held within the regional assessment process on molluscs in the Quebec coastal waters in Quebec region following the 2005 fishing season. This advisory process was held on January 17 and 26, 2006 at the Maurice-Lamontagne Institute in Mont-Joli. During these meetings, the assembly reviewed the stock status of the molluscs in the Quebec coastal waters exploited by both commercial and recreational fishery as well as certain environmental parameters that prevailed during the last fishing seasons. Therefore, these proceedings contain the essential parts of the presentations and discussions held and relate the main recommendations and conclusions that were presented during the review.

BRULOTTE, S., M. BOURGEOIS, M. GIGUÈRE, D. HÉBERT, J. CÔTÉ, S. DUBÉ, G. CLICHE, 2008. Évaluation de structures et de scénarios d’élevage en suspension du pétoncle géant (Placopecten magellanicus) aux Îles-de-la-Madeleine, Québec. Rapp. tech. can. sci. halieut. aquat., 2808, 106 p .

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This study, which took place between 2001 and 2004, was conducted in the lagoons of Grande Entrée (GE1 and GE2 sites) and of Havre aux Maisons (HAM site) in the Îles-de-la-Madeleine. The principle objectives were to compare the survival, loss and growth of sea scallop cultures from five types of structures and assess the quantity of biological fouling on these structures. The tested structures were the earring (BO), the pocket net (FP), the pearl net (PJ), the oyster table net (PO) and the Wang-Joncas lantern (WJ). In the fall of 2001, the FP, PJ, PO and WJ structures were watered at the three sites, then sampled after six months, one year and two years. A second watering was made in the spring of 2002 with five types of structures, and samples were collected after three months, one year and two years. Some structures were cleaned during these tests. The survival rates after two culture years were under 40 % for the 2001 test and between 30-58 % for the 2002 test. There were two presumed causes of mortality, the first by handling during scallop watering operations, and the second was environmental in the fall of 2002, more noticeable in the Grande Entrée lagoon. Results showed a significant effect from the site and structure used on scallop survival. Two years after the 2001 cultures, scallop losses were more significant in the FP and WJ structures (12-81%) than in PJ and PO (under 8 %). Two years after the watering, the mean size of culture scallops from 2001 increased from 35-41 mm to 68- 84 mm, depending on the site and the structure. The highest mean sizes were obtained in the structures FP at GE1 and GE2 and WJ at HAM. Overall, the scallops from the BO and FP structures were largest. Growth in the PO was generally lower than the values observed in the pelagic structures tested. The effect of cleaning the structures on scallop survival, loss and growth varied and did not indicate any obvious trend between one and two culture years. For the BO, cleaning conducted at opportune moments would reduce detaching due to the high abundance of mussels. There was little fouling on the FP and cleaning was easy and could be done mechanically. The WJ was heavy, cumbersome and difficult to clean due to the strong adherence of fouling. The PO structure, on a benthic table, was bulky and difficult to handle. The overall results, technical and biological, appear to show that the BO and FP structures are likely the most interesting to use for cultures in the Îles-de-la-Madeleine lagoon environment. Scallop survival and growth in these structures was good.

GIGUÈRE, M., S. BRULOTTE, F. HARTOG, 2007. Évaluation de quelques gisements de mye commune (Mya arenaria) de la rive sud de l'estuaire du Saint-Laurent en 2005 et 2006. Rapp. tech. can. sci. halieut. aquat., 2738, 107 p .

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In 2005 and 2006, a little over 19 km2 of foreshore were surveyed on the south shore of the St. Lawrence Estuary, between Kamouraska and Capucins. Fourteen sites were sampled in 2005 and three of them, Pointe des Riou, Rimouski and Capucins, were revisited in 2006. Survey results show that these beds cover an area varying between 0.1 to 4.5 km2. The Rimouski bed is the largest followed by Kamouraska, which measures 1.8 km2. The beds at Îlets D'Amours (0.1 km2), Anse aux Coques (0.1 km2), Baie Hâtée (0.2 km2) and Capucins (0.2 km2) cover smaller areas. Work conducted at Anse des Méchins (Petits-Méchins) failed to locate any clam aggregation there. The size of the beds surveyed often differs from what is presented in the literature. Part of the discrepancies recorded could be on account of methodological differences or changes in environment or habitat. Most of the sampled beds are located in proximity or at the mouth of rivers and are usually exposed to north winds (NW, N and NE). In 2005, legal size clams (≥51 mm) were absent from Kamouraska, Anse au Persil and Îlets D'Amours beds. In the other beds, the mean density of legal size clams varies from 3.4 individuals/m2 at Batture de Tobin to 32.5 individuals/m2 at Capucins. Maximum densities recorded for this category of clams vary between 25 and 150 individuals/m2. Results from 2006, at Pointe des Riou, Rimouski and Capucins differ from 2005. These differences could be explained by very small scale changes in abundance and demographic structure, seasonal and annual variations of these two parameters and by the methodologies used. The maximum size of clams is less than 60 mm on the beds located west of the surveyed area, but reached, except for Baie du Ha! Ha! and Anse aux Coques, nearly 80 mm over those located east of Batture de Tobin. Results from work conducted on a few experimental plots suggest a more rapid growth at Pointe des Riou, intermediate at Capucins and weaker at Rimouski. Comparisons of allometric relations for each of these three beds, relations that are determined using specimens collected over larger areas suggest however, that for the same lenght, clams coming from Rimouski have a whole weight and a weight of dry viscera higher than to the others sites. Among all the sampled sites in 2005 and 2006, Rimouski and Capucins stand out on account of, among other things, their easy access, good protection of winds, strong clam abundance, a high percentage of colonized area and a demographic structure where all size classes are well represented and which include a significant proportion of larger size individuals at legal catch size.

GIGUÈRE, M., S. BRULOTTE, C. DULUC, F. HAZEL, S. PEREIRA, M. GAUDET, 2007. Recensements de l'huître américaine (Crassostrea virginica) dans le bassin aux Huîtres et la baie Clarke aux Îles-de-la-Madeleine, Québec. Rapp. tech. can. sci. halieut. aquat., 2695, 46 p .

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GIGUÈRE, M., S. BRULOTTE, S. BRILLON, 2007. Essais de 12 modèles de casiers de pêche au buccin commun (Buccinum undatum) en milieu naturel et observations comportementales en bassin. Rapp. tech. can. sci. halieut. aquat., 2696, 36 p .

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BRULOTTE, S., M. GIGUÈRE, 2007. Reproduction et taille à la maturité sexuelle de la mye commune (Mya arenaria) au Québec. Rapp. tech. can. sci. halieut. aquat., 2698, 40 p .

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BRULOTTE, S., M. GIGUÈRE, S. BRILLON, F. BOURQUE, 2006. Évaluation de cinq gisements de mye commune (Mya arenaria) aux Îles-de-la-Madeleine, Québec, de 2000 à 2003. Rapp. tech. can. sci. halieut. aquat., 2640, 92 p .

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GIGUÈRE, M., S. BRULOTTE, N. PAILLE, J. FORTIN, 2005. Mise à jour des connaissances sur la biologie et l'exploitation de la mactre de l'Atlantique (Spisula solidissima) aux Îles-de-la-Madeleine. Rapp. tech. can. sci. halieut. aquat., 2587, 32 p .

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The purpose of this document is to present the knowledge base on Atlantic surfclam (Spisula solidissima), Dillwyn 1817) biology, identify the species' spawning period in the Iles-de-la-Madeleine and provide an assessment of harvesting of this resource. The information that is presented comes from the literature, a 2003 study on the Atlantic surfclam reproductive cycle and an analysis of fishery statistics.

GIGUÈRE, M., S. BRULOTTE, M. NADEAU, 2004. Caractérisation de quatre sites potentiels à l'ensemencement du pétoncle géant, Placopecten magellanicus, aux Îles-de-la-Madeleine, Québec. Rapp. tech. can. sci. halieut. aquat., 2564, 77 p .

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Seeding site selection is a decisive factor in the success of commercial seeding operations for sea scallops (Placopecten magellanicus). Seabed characteristics are critically important in ensuring high scallop survival and growth rate. The following results present the characteristics of four sites, Sud-Ouest, Chaîne-de-la-Passe, Millerand and Pointe-du-Ouest located south and southeast of Îles-de-la-Madeleine, in terms of their relief, sediments and the presence of predators. Five approaches were used to characterize the sites: 1) 100 % site coverage using multibeam acoustic surveys, 2) sediment classification using a single-beam echo sounder, 3) grab sampling and particle size analysis of sediments, 4) a video-camera inventory of benthic fauna and 5) an analysis of historical data from dredge scallop surveys. Even though, on the whole, the trends are similar, the results obtained highlight the limits of each method used in characterizing the seabed. The integrated approach used, here, combining the sampling methods contributed to seabed improve characterization. The Sud-Ouest site is the shallowest of the four sites studied. The dominant substrate of this site is sand. The Chaîne-de-la-Passe site is the largest and the bottom is quite smooth, consisting mainly of sand and sandy gravel. The Millerand site is the smallest of the four sites sampled. Its substrate is mainly sand, sandy gravel and pebble. The Pointe-du-Ouest site is the deepest of the four sites studied, with a substrate consisting of a mixture of sand, gravel and pebble in varying concentrations. Compared with other sites, the contents in gravel and in pebble are higher on the Pointe-du-Ouest site. The area of heterogeneous bottom (gravely sand, sandy gravel, pebble and rock), which is recognized as suitable scallop habitat, is estimated at about 4, 39, 4 and 28 km2 respectively for each of these sites. Apart from the sea scallop, the most prevalent (predators) species at the sites sampled are the sea stars Asterias vulgaris, Crossaster papposus and Leptasterias polaris as well as crabs, Cancer irroratus and Hyas sp.

DIONNE, M., M. GIGUÈRE, S. BRULOTTE, 2004. Synthèse des méthodes de captage du pétoncle utilisées dans le monde. Rapp. manus. can. sci. halieut. aquat., 2683, 37 p .

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The first trials in scallop culture for commercial purpose were carried out in Japan during the year 1930-1940. Following their success, several other countries attempted to institute scallop culture, inspired by the Japanese collecting and raising methods. The industry is now expanding, and in recent years new collecting techniques adapted to different species and particular environmental conditions have been devised. This document presents a sumary of the scallop collecting methods used by different regions of the world. It includes not only commercial methods, but also techniques tested esperimentally. The techniques used for the various scallop spat collectors, their installation and their immersion times are resumed, as well as their characteristics and effiency. The influence of invertebrates that cohabit the collecting devices is considered. Finally, the recent orientation of countries with the industry is also discussed.

GIGUÈRE, M., S. BRULOTTE, D. LEBLANC, 2004. Aperçu de l'exploitation de la mye commune (Mya arenaria) entre la rivière Betsiamites et Baie-Trinité, Côte-Nord, Québec. Rapp. tech. can. sci. halieut. aquat., 2539, 31p .

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The commercial exploitation of softshell (Mya arenaria) is a significant area of development for the Upper North Shore. However, available resources are limited by the closing of beds due to the presence of toxic algae and bacterial contamination. Industry practice of rejecting broken, egg-laying and large-sized (70 mm and more) softshell clams results in the partial loss of the resource available. The general objectives of this project are to document for Upper North Shore the problem of large-sized (70 mm and more) softshell clams rejected, to locate and estimate the biomass available of this softshell clam category, to measure the impact of fishing methods and unwanted softshell clams elimination on the survival of this species. Most harvesters consulted in the regional county municipality of Manicouagan have been doing this job since less than 5 years. They go to the Pointe-aux-Outardes flats mainly the Grosse Pointe site. Half of the respondents think that the size of softshell clams seems to have decreased, that softshell clams are less abundant, and that the catch yield decreased over the last years on this site. In the western part of the Pointe-aux-Outardes sector (pointe du Bout), softshell clams are larger and in greater numbers than those found close to the Grosse Pointe. Approximately a quarter of the harvest would be rejected by the industry that is to say because softshell clams are too large or because they are broken. Half of the respondents mentioned that they even rejected softshell clams on beds, and the other half at the time of the sale. Part of these softshell clams is used for personal consumption. During last years, the fishing season in this sector was of short duration, that is to say from March to May, and then from October to November, because beds were closed in the summer due to the presence of toxic algae and fecal coliforms. In 2002, on Pointe-aux-Outardes's sector harvesting was allowed for a total of 107 days with a total landing of 149.6 t. The size structure of the softshell clams population found on the western sector of Pointe-aux-Outardes includes a significant number of individuals of very large size, and few young individuals. The biomass of softshell clams equal and larger than 70 mm found at the (pointe du Bout) is estimated at approximately 681 t and whereas that of the Grosse Pointe is now imprecise. Approximately 8 years and 13 years would be needed to reach respectively the size of 51 mm and 70 mm. However, before landing more large individuals, it would be necessary to know the mechanism of recruitment of the softshell clams, this to ensure the conservation and the sustainable development of this resource.

BRULOTTE, S., M. GIGUÈRE, 2003. Évaluation d'un gisement de mye commune (mya arenaria) de l'embouchure de la rivière Mingan. Rapp. tech. can. sci. halieut. aquat., 2511, 58 p .

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The first objectives of the work completed on the soft-shell clam (Mya arenaria) found at the Mingan river mouth was to evaluate emerged and immersed surfaces, abundance, commercial biomass, and demographic structure of the clam population as well as to characterize the environment (sediment and rellated species). The second objective was to estimate the growth and survival of both clams living on this natural bed and those living in suspension culture. The results of the survey made in 2001 showed that the clams were distributed south west of the sampled intertidal zone. The clam bed total surface added up to 0,47 km2, while that of high density aggregations (more than 20 legal size clams/m2) was of 0,25 Km2. The total abundance of clams on the bed was estimated at 24,8 millions of individuals, including 11,4 millions (46 %) of legal size clams (≥51mm). The number of legal size clams found on the high density portion of the bed was approximatly 9,4 millions of individuals. The total biomass of calms was estimated at 366,4t on a live weight basis, for the bed, that is to say 309,0t of legal size clams, and 57,4t of under-size clams. The biomass of legal size clams available on the high density portion was 254,6t, on a live weight basis. On the other hand, the growth rate of clams was estimated at approximatly 5 mm for the period extended from June to October 2001.

ROY, I., M. GIGUÈRE, S. BRULOTTE, M. GAGNON, 2003. Évaluation de douze gisements de mye commune (Mya arenaria) du sud de la Gaspésie. Rapp. tech. can. sci. halieut. aquat., 2469, 140 p .

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In 2001, the Societe de developpement de l'industrie maricole initiated a survey of the following shellfish sectors: Bassin de la riviere Nouvelle, Carleton (Centre, Ouest and Sud), Clapperton, Pointe Verte (Maria), Bonaventure (Est et Ouest), Port-Daniel, Baie du Grand Pabos, Estuaire de la rivere Malbaie and Estuaire de la riviere Saint-Jean. The objectives of this project were to 1) delimit within each sector the major soft-shell clam (Mya arenaria) beds; 2) determine for each bed the abundance and the biomass of clam, 3) identify the submerged areas at low tide and 4) describe a few biological parameters. Pointe Verte (Maria) was surveyed in November 2001 while the 11 other sectors were surveyed in 2002. The 12 sectors were sampled systematically, but with some alternatives according to the environment. The quadrats were sampled with a shovel or a siphon. This document presents a physical description of the surveyed beds, the abundance of clam by size categories estimated by both kriging and conventional descriptive statistics, biomass, size and age distribution, as well as the number of small macoma. The areas described in this report represent the most important and accessible soft-shell clam beds.

PELLETIER, L., H. BOURDAGES, S. BRULOTTE, 2001. Estimation de la perte de poids subie par l'oursin vert (Strongylocentrotus droebachiensis) suivant sa sortie de l'eau et comparaison de deux techniques de mesure du diamètre du test. Rapp. can. ind. sci. halieut. aquat., 264, 14 p .

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An evaluation of the weight loss by green sea urchins during storage was carried out in response to requests by the working group on green sea urchins and the urchin fishing industry of Quebec. A laboratory experiment using sea urchins from our wetlab facilities allowed us to evaluate the weight loss over six days following the removal of sea urchins from the water and subsequent cold-room storage at 4 degreeC. The weight loss varied in relation to the storage period and the initial weight. The daily average weight losses, expressed as percentages of the initial weight, were rather stable over the experiment (from 0 to 144 hours). For sea urchins of commercial size (test diameter greater than or equal 50 mm), the weight losses after 24, 48, 72, and 144 hours of storage were estimated to be approximately 2, 5, 7, and 14 % of the initial weight of the urchin when it was removed from the water. Feeding of sea urchins prior to removal had no effect on the observed weight loss. In addition, two techniques for measuring the test diameter using a vernier caliper was compared. A fast measurement gave results comparable to those obtained when special care was taken to the exact positioning of the calipers on the opposite ambulacral and interambulacral plates.

GIGUÈRE, M., S. BRULOTTE, 2000. Buccin des eaux côtières du Québec. Rapport sur l'état des stocks, C4-09, 7 p .

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BRULOTTE, S., A. FRÉCHET, 2000. Indice de saturation de la palangre et du filet maillant dans les relevés des Pêches Sentinelles à la morue dans le nord du golfe du Saint-Laurent ; Saturation index for longlines and gill nets in Sentinel Fisheries of cod in the Northern Gulf of St. Lawrence. MPO, Secrétariat canadien pour l'évaluation des stocks, Document de recherche ; DFO, Canadian Science Advisory Secretariat, Research Document, 2000/118, 34 p .

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Catch rates from cod directed fixed gear Sentinel Fisheries thus complement other tools available for the assessment of the northern Gulf of St. Lawrence cod stock. The saturation index was estimated for longlines and gill nets used in the cod directed Sentinel Fisheries from 1994 to 1998. The areas covered by these surveys are the West Coast of Newfoundland and North Shore of Quebec, 49 fishing sites. Since the onset of Sentinel Fisheries by fixed gear, fishers have used their traditional fishing sites and traditional fishing gear as prior to the moratorium on the cod fishery. The number of cod (Atlantic and Ogac) caught was generally calculated from the number of Atlantic cod sampled. For the other species caught (fish, sharks, crustacean, etc) an average individual weight was used. The index saturation of the longline was calculated from the total number of specimens caught divided by number of hooks used. For the gill nets, the index was calculated from the total number of specimens caught divided by number of nets used. A total of 2985 trips were done with longlines between 1994 and 1998, of which 2591 were done in Newfoundland and 394 in Quebec. Out of a total of 2985 trips done, 104 had no catch, 1113 had only cod, 1663 had mixed catches of cod and other species and only 105 without cod but with other species caught. Cod represents more than 60 % of the numbers caught in over of the trips (62.4 %). The index of saturation (all species) in the longline is low for most observations; 80.8 % of the trips had saturation indices between 0 and 20 %. A total of 4311 trips were done between 1994 and 1998 with gill nets of which 1709 were done in Newfoundland and 2602 in Quebec. Out of the 4311 trips done only 81 had no catch, 838 trips had caught only cod, 3192 had cod and other species and only 200 trips had species other than cod caught. In Newfoundland, the proportion of cod caught in gill nets are similar to longline with 57.3 % of trips having over 60 % cod in their catches. In Quebec, this proportion drops to 30,3 % of the trips with over 60 % of cod catches. In Newfoundland and Quebec, the frequency of a saturation of 25 individuals or less per net is generally over 80 % of the trips. The gear saturation is a measure of loss of efficiency of a gear as the number of fish caught increases. Saturation has thus a very direct effect on catch rates. In the case of Sentinel Fisheries, for most trips with longlines and gill nets, the saturation indices are likely too low to bias catch rates.

BRULOTTE, S., A. FRÉCHET, 2000. Saturation index for longlines and gill nets in Sentinel Fisheries of cod in the Northern Gulf of St. Lawrence. DFO, Canadian Stock Assessment Secretariat, Research Document, 2000/118, 34 p .

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Catch rates from cod directed fixed gear Sentinel Fisheries thus complement other tools available for the assessment of the northern Gulf of St. Lawrence cod stock. The saturation index was estimated for longlines and gill nets used in the cod directed Sentinel Fisheries from 1994 to 1998. The areas covered by these surveys are the West Coast of Newfoundland and North Shore of Quebec, 49 fishing sites. Since the onset of Sentinel Fisheries by fixed gear, fishers have used their traditional fishing sites and traditional fishing gear as prior to the moratorium on the cod fishery. The number of cod (Atlantic and Ogac) caught was generally calculated from the number of Atlantic cod sampled. For the other species caught (fish, sharks, crustacean, etc) an average individual weight was used. The index saturation of the longline was calculated from the total number of specimens caught divided by number of hooks used. For the gill nets, the index was calculated from the total number of specimens caught divided by number of nets used. A total of 2985 trips were done with longlines between 1994 and 1998, of which 2591 were done in Newfoundland and 394 in Quebec. Out of a total of 2985 trips done, 104 had no catch, 1113 had only cod, 1663 had mixed catches of cod and other species and only 105 without cod but with other species caught. Cod represents more than 60 % of the numbers caught in over of the trips (62.4 %). The index of saturation (all species) in the longline is low for most observations; 80.8 % of the trips had saturation indices between 0 and 20 %. A total of 4311 trips were done between 1994 and 1998 with gill nets of which 1709 were done in Newfoundland and 2602 in Quebec. Out of the 4311 trips done only 81 had no catch, 838 trips had caught only cod, 3192 had cod and other species and only 200 trips had species other than cod caught. In Newfoundland, the proportion of cod caught in gill nets are similar to longline with 57.3 % of trips having over 60 % cod in their catches. In Quebec, this proportion drops to 30,3 % of the trips with over 60 % of cod catches. In Newfoundland and Quebec, the frequency of a saturation of 25 individuals or less per net is generally over 80 % of the trips. The gear saturation is a measure of loss of efficiency of a gear as the number of fish caught increases. Saturation has thus a very direct effect on catch rates. In the case of Sentinel Fisheries, for most trips with longlines and gill nets, the saturation indices are likely too low to bias catch rates.

GIGUÈRE, M., S. BRULOTTE, P. GOUDREAU, 2000. État des stocks de pétoncles des eaux côtières du Québec. MPO, Secrétariat canadien pour l'évaluation des stocks, Document de recherche ; DFO, Canadian Science Advisory Secretariat, Research Document, 2000/086, 57 p .

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This area is subdivided into 16 management units comprising the Îles-de-la-Madeleine, the Gaspé and the North Shore. In 1999, there were 82 regular licences in operation. In Québec, commercial harvesting is directed at both the Iceland scallop (Chlamys islandica) and the sea scallop (Placopecten magellanicus). Landings normally consist of the meat (adductor muscle) or whole scallops. In 1999, preliminary landings in Québec amounted to nearly 331 t of meat (2 747 t live weight), with the North Shore contributing 65 %, the Gaspé 26 % and the Îles-de-la-Madeleine 9 % of this figure. The Îles-de-la-Madeleine landings stood at about 31 t in 1999, down 27 % from 1998. Two new fairly abundant cohorts of pre-recruits were present in 1999; they will be recruited to the fishery in 2000 and 2001. Commercial yields hit an all-time low in 1998 and 1999. The catches in the Gaspé are made primarily in Chaleur Bay (19A) and around Anticosti Island (18B and 18C). In area 19A, where landings have been on the rise since 1994, a total of nearly 36 t of meat was landed in 1999. Catches per unit effort of sea scallops have been small but stable since 1995. In 1998 and 1999, fishers directed their fishing effort at Iceland scallops because of the low abundance of sea scallops on fishing grounds. Harvesting activities in 1999 included a new scallop bed (Red Island) located at the western limit of area 17A. The yields recorded there are the highest for all of Quebec. The exploitation rate has been estimated at 15 %. Areas 18B and 18C are still under development. In 1999, the North Shore catch totalled some 214 t of meat. Landings in area 16A have increased owing to exploitation of the new Red Island scallop bed. The status of the scallop resource in areas 16B and 16C appears to be stable. The landings in areas 16D, 16E, 16F, 16G and 18A stood at about 142 t in 1999. Harvesting in areas 16D and 16G is still being developed. In area 16E, the 1999 catch totalled 57.2 t of muscle and the catches per unit effort held steady. In area 16F, the landings were stable but fishing effort increased by 22 % in 1999 over the 1998 level. Between 1994 and 1997, the yields were stable but in 1998 they showed a marked decline. In area 18A, landings and catches per unit effort have been on the rise since 1997. The exploitation rate was estimated at 4 % in 1999. There have been few landings in area 16H since 1996. In area 15, landings have dropped by 53% from 1998, mainly as a result of a decrease in effort.

GIGUÈRE, M., S. BRULOTTE, 2000. Whelk in Québec Coastal Waters. Science, Stock Status Report, C4-09, 7 p .

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GIGUÈRE, M., S. BRULOTTE, P. GOUDREAU, 1998. État des stocks de pétoncles des eaux côtières du Québec. MPO, Secrétariat canadien pour l'évaluation des stocks, Document de recherche, 98/73, 38 p .

This report presents data used in to assess the scallop populations in the coastal waters Quebec. In Quebec, there are 17 management units for the scallop fishery covering the areas around Îles-de-la-Madeleine, the Gaspé peninsula and along the North Shore. In 1997, 82 regular permits were issued. Scallops from the Gaspé peninsula and the North Shore were assessed using commercial indices. Scallops from Îles-de-la-Madeleine and area 16De on the North Shore were assessed using both commercial indices and research survey indices. In Quebec, Iceland scallops and sea scallops are harvested indiscriminately. The landings are usually in the form of meat. In 1997, scallop landings in Quebec amounted to 260 t meat, of which 69 % was from the North Shore, 16 % from the Gaspé peninsula and 15 % from Îles-de-la-Madeleine. Scallop landings in Îles-de-la-Madeleine were around 39 t in 1997, which is 17 % lower than in 1996. A new cohort of prerecruits was present in 1997, but it is weak. After the 1997 fishing season, almost all scallop beds were decimated and the harvestable biomass was at its lowest level since 1984. No improvement in recruitment to the fishery is expected before the year 2000. Fishing intensity in Îles-de-la-Madeleine is disproportionately high considering the availability of scallops. Landings from the Gaspé peninsula are mostly from Chaleur Bay (19A) and Anticosti Island (18B). Area 19A landings have been stable since 1986, except for 1990 and 1997. In 1997, landings reached 21,4 t of meat, the highest level since 1987. Catches per unit effort showed minor fluctuations over that period, including a slight increase in 1997. Increased fishing effort over the last few years may be detrimental for the scallop populaiton of area 19A. The situation in areas 17A (northern shore of the Gaspé peninsula) and 18B is not worrisome for the moment, since fishing intensity in these areas is low. In 1997, around 180 t of scallop meat were landed on the North Shore of Quebec. The fishery in areas 16A, 16B and 16C on the Upper North Shore is unstable. Pas exploratory fishing and the present status of the fishery indicate a limited potential in areas 16A and 16B. There has been a strong increase in fishing effort in area 16C. Harvesting must be carefully controlled in order to avoid overfishing. In 1997, scallop landings in areas 16Do, 16De, 16G, 16E and 18A amounted to about 143 t, coming mostly from area 16De. These areas are presently the most productive in Quebec. Catches per unit effort decreased almost everywhere except in 16Do and 16G. From 1993 to 1996, natural mortality increased considerably in areas 16De, 16G and 18A. In 1997, however, mortality rates were at most 24 % in these areas. The increasing mortality rate in these areas up until 1996, and the decreasing catch rates in areas 16De, 16G and 18A indicate that vigilance is necessary. In 1997, landings increased in area 15, but there were very little or no landings in areas 16F and 16H. The future of the Iceland scallop fishery in area 15 is uncertain.

GENDRON, L., S. BRULOTTE, C. CYR, G. SAVARD, 1998. Développement de la pêche et état de la ressource de crabe commun (Cancer irroratus) en Gaspésie et aux Iles-de-la-Madeleine (Québec) de 1995 à 1997. Rapp. tech. can. sci. halieut. aquat., 2248, 37 p .

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Exploitation of the rock crab (Cancer irroratus) on Canada's Atlantic coast is relatively new. Experimental fishing began in the southern part of the Gulf of St. Lawrence in 1974. In Quebec, markets developed later, and fishing began only in 1988. After a mere two years of operation, fishing practically ceased for lack of buyers, but a new start was made in 1995. When fishing first began, the Department of Fisheries and Oceans implemented a management plan to control development of this new fishery and maintain the population's reproductive potential. Fishing is regulated by a minimum legal shell width of 102 mm (4"), a ban on landing females, use of selective gear to minimize lobster (Homarus americanus) catches, and a limit on trap numbers. The number of licenses is limited in certain areas, as are catches. In 1997, Quebec rock crab landings reached 1,040 t, a 51 % rise from 1996. In the Gaspe, landings totalled 592 t, accounting for 57 % of Quebec landings. In the Magdalen Islands in 1997, landings increased by 125 % compared to 1996, reaching 448 t. They represented 43% of Quebec landings. The rock crab fishery is still expanding and the opening of new fishing grounds in 1997 contributed to the increase in landings. In the Gaspe, catch rates have been falling since 1995, quite steeply in some areas. In the Magdalen Islands, 1997 catch rates were lower than in 1996 but equivalent to those of 1995. Declining catch rates may reflect depletion of the accumulated biomass of these virgin stocks, but they could also be due to changes in fishing patterns in space and time in relation to seasonal crab movements or changes in the pattern of abundance that could be cyclic. At present, it is hard to detect the effects of harvesting on the populations. We insist on the need for slow and cautious development of this fishery because of concerns over the possible impact of rock crab harvesting on lobster stocks. The two species interact sufficiently to justify strict and cautious management of the crab fishery.

GIGUÈRE, M., S. BRULOTTE, 1997. État des stocks de pétoncle des eaux côtières du Québec. MPO, Secrétariat canadien pour l'évaluation des stocks, Document de recherche, 97/80, 36 p .

This report presents data used in the assessments of the scallop populations in the coastal waters Quebec. In Quebec, there are 17 management units for the scallop fishery covering the areas around Îles-de-la-Madeleine, the Gaspé peninsula and along the North Shore. In 1996, 82 regular permits were issued. The stock assessments for Gaspé peninsula scallops and North Shore scallops is based on commercial indices. For Îles-de-la-Madeleine scallops and area 16De scallops on the North Shore, both commercial indices and research survey indices are used in assessments. In Quebec, Iceland scallops (Chlamys islandica) and sea scallops (Placopecten magellanicus) are fished indiscriminately. The landings are usually in the form of meat. In 1996, preliminary scallop landings in Quebec amounted to 260 t meat, of which 71 % was from the North Shore, 18 % from Îles-de-la-Madeleine and 11 % from the Gaspé peninsula. Scallop landings in Îles-de-la-Madeleine were around 46 t in 1996, which is 23% lower than in 1995. Very few prerecruits (scallops <70 mm) were observed in 1996. After the 1996 fishing season, almost all scallops beds were decimated. Fishing intensity in Îles-de-la-Madeleine is disproportionate to the availability of scallops. Only the eastern part of Chaîne-de-la-Passe fishing ground could support fishing in 1997 at a reduced intensity. Between now and 1999, recruitment shows no encouraging sign for the fishery. Landings from the Gaspé peninsula are mostly from Chaleur Bay (19A) and Anticosti Island (18B). Area 19A landings have been stable since 1986. The fluctuations observed in Gaspé peninsula landings are due to the periodic fishing of Iceland scallops in area 18B. The decrease in catch per unit effort in area 19A should be watched. The situation in areas 17A (northern shore of the Gaspé peninsula) and 18B is not worrisome for moment, since fishing intensity on the resource in these areas is low. In 1996, 185 t of scallop meat were landed on the North Shore of Quebec. The fishery in areas 16A, 16B anc 16C on the Upper North Shore is unstable. Exploratory fishing in the past and the present status of the fishery indicate limited potential in these areas. The Middle North Shore is the most productive for scallops in Quebec. Landings peaked in 1990 et 300 t. In 1996, scallop landings amounted to 146 t, coming mostly from area 16De. Over the past five years, natural mortality has increased considerably in areas 16D and 16G, and catch per unit effort has dropped in area 16G. In area 16E, the climatic conditions are not favorable to a sustained fishery. In area 18A (Anticosti Island), increasing catch per unit effort seems to indicate good status for the scallop beds. Landings on the Lower North Shore are low. The stock status of scallops on the Lower North Shore is clearly at a critical level. It is apparent that fishing pressure exceeds the production capacity of the scallop populations.

GIGUÈRE, M., R. MILLER, S. BRULOTTE, D. GUAY, 1995. Sea scallops and iceland scallops on the Québec coast (fishing areas 15, 16, 17, 18, 19 and 20). Pages 55-89 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) .

GIGUÈRE, M., G. CLICHE, S. BRULOTTE, 1995. Synthèse des travaux réalisés entre 1986 et 1994 sur le captage du naissain de pétoncles aux Îles-de-la-Madeleine. Rapp. tech. can. sci. halieut. aquat., 2061, 71 p .

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Part of the research program on scallop farming and restocking (REPERE), involved several experimental collections of wild scallop spat in Îles-de-la-Madeleine. These studies were to precede seeding and restocking of sea scallops (Placopecten magellanicus, Gmelin) on fishing grounds in the area. The study site included 25 sampling stations located southwest of Îles-de-la-Madeleine at depths of 10 to 45 m. Movements of the water mass were investigated using a transmitting drifter buoy and current meters. Scallop larvae were sampled using a plankton net, and scallop spat were collected with artificial collectors. Sea scallop genitors occur mainly on the Chaîne-de-la-Passe, Étang-du-Nord, and Dix-Milles fishing grounds. Sea scallops usually spawn during a two week period between mid-August to mid-September. In 1994, the density of larvae was maximal at the beginning of September with up to 149 larvae m-3 obtained near the fishing grounds; densities then decreased and varied from 0 to 30 larvae m-3 until mid-October. The size of the larvae ranged from 105,8 to 292,5 µ, and the size frequency showed several modes. Currents over the study site were directed from northeast to southwest, which would bring about a mixing of larvae between fishing beds. From the information obtained on the marine currents, two retention zones, particularly during September, were observed : one in the Sud-Ouest area, the other in the Étang-du-Nord area. The peak spat settlement period is usually in October. Collectors were set in mid-October and recuperated in December in order to minimize settlement of undesirable species such as the blue mussel (Mytilus adulis, L.) and the arctic saxicave (Hiatella arctica, L.). Several factors affect the success of scallop spat settlement : proximity to genitors, length of spawning period, marine currents, the location of collectors and their position in the water column. The density of spat was usually higher in Sud-Ouest area where it varied from 62 to 2 071 spat collector-1, depending on the year. However, the results obtained up to now on movements of the water mass, the location of genitors and concentrations of larvae indicate that the best places for spat collection are in the Étang-du-Nord and Chaîne-de-la-Passe areas. In Sud-Ouest area (mostly a sandy bottom), the lack of adequate natural substrate for scallop spat settlement would probably explain the success of artificial collectors in this area. The position of collectors in the water column for optimal spat collecting success appears to be 16 to 25 m below the surface. The collectors in the Étang-du-Nord and Chaîne-de-la-Passe areas may have been too deep for optimal collecting success. Of the different substrates used in the collectors, NetronSM was found to be an efficient substrate for scallop spat.

GIGUÈRE, M., S. BRULOTTE, R. MILLER, 1995. Distribution, croissance et mortalité du pétoncle d'Islande et du pétoncle géant entre Kegaska et Vieux-Fort sur la Basse-Côte-Nord du Québec en 1993 ; Distribution, growth and mortality of Iceland scallops and sea scallops between Kegaska and Vieux-Fort on the lower North Shore of Quebec in 1993. Rapp. tech. can. sci. halieut. aquat. ; Can. Tech. Rep. Fish. Aquat. Sci., 2033, 27 p .

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A systematic survey of scallop beds was carried out in 1993 on the Lower North Shore of Québec between Kegaska and Vieux-Fort. Subsamples were collected from the survey area (Iceland scallops) and from a small bay near Watagheistic Island (sea scallop and Iceland scallops) for histopathological analysis. Of the 303 stations established for the exploratory survey, only 109 stations were dragged because the others occurred on bottoms too deep or too rough to sample. Iceland scallops were present at 51 of the stations dragged, while no sea scallops were found at any of the survey stations. Only 7 stations had scallop densities greater than 10 per 100 m2. The age of the scallops ranged from 2 to 21 years with the dominant age classes of 11 and 12 years old. The mortality rate varied from 0.105 to 0.239, with the highest occurring near Kegaska. The growth rate and the slope in the linear relationship between shell size and muscle weight showed higher values in the western part of the survey area. Nearshore sampling is a small bay near Watagheistic Island revealed densities ranging from 0.16 to 8.99 per 100 m2 for sea scallops and from 0.14 to 6.81 per 100 m2 for Iceland scallops, respectively. The mortality rate here was very high, with means per station of 0.823 for sea scallops and 0.645 for Iceland scallops. The results from the nearshore sector in 1993 confirm a mass mortality phenomenon that has affected some of the scallops beds of the northern Gulf of St. Lawrence. The histopathological analysis revealed hemocytic infiltration, abscesses with necrotic blood cells and various parasites in many of the scallop tissue sections, especially from the digestive gland and gills. The prevalence of turbellarians was high, ranging from 35.7 % to 81.2 % in sea scallops and 5.3% to 60.0 % in Iceland scallops. Rickettsia-like inclusions and ciliates occurred at relatively high intensities, with maximums of 17.7 and 11.1 per cm2 of gill section, respectively. Nevertheless, the cause or causes of the massive mortality of scallops in this area could not be determined from the histopathological analysis.

GIGUÈRE, M., G. CLICHE, S. BRULOTTE, 1995. Cycle reproducteur du pétoncle géant, Placopecten magellanicus, et du pétoncle d'Islande, Chlamys islandica, aux Îles-de-la-Madeleine. MAPAQ, DRST, Doc. rech., 94/06, 11 p .

GIGUÈRE, M., R. MILLER, S. BRULOTTE, D. GUAY, 1995. Pétoncle géant et pétoncle d'Islande des côtes du Québec (zones de pêche 15, 16, 17, 18, 19 et 20). Pages 57-92 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) .

GIGUÈRE, M., G. CLICHE, S. BRULOTTE, 1994. Reproductive cycles of the sea scallop, Placopecten magellanicus (Gmelin), and the Iceland scallop, Chlamys islandica (O.F. Müller), in Îles-de-la-Madeleine. MAPAQ, DRST, Doc. rech., 94/10, 24 p .

GIGUÈRE, M., G. CLICHE, S. BRULOTTE, 1994. Reproductive cycles of the sea scallop, Placopecten magellanicus (Gmelin), and the Iceland scallop, Chlamys islandica (O.F. Müller), in Îles-de-la-Madeleine, Canada. J. Shellfish Res., 13: 31-36 .

GIGUÈRE, M., S. BRULOTTE, 1994. Comparison of sampling techniques, video and dredge, in estimating sea scallop (Placopecten magellanicus, Gmelin) populations. J. Shellfish Res., 13: 25-30 .

GIGUÈRE, M., G. CLICHE, S. BRULOTTE, 1994. Succès de reproduction du pétoncle géant, Placopecten magellanicus, dans la lagune de la Grande-Entrée (Îles-de-la-Madeleine, golfe du Saint-Laurent). Bull. Aquac. Assoc. Can., 94(3): 16-21 .

GIGUÈRE, M., R. MILLER, S. BRULOTTE, 1994. Rapport sur l'état du pétoncle du Québec. MPO, Pêches de l'Atlantique, Document de recherche, 94/80, 61 p .

The 1993 Quebec scallop landings were from, in order of importance, the North Shore (75 %), Îles-de-la-Madeleine (21.4 %) and the Gaspé peninsula (4.5 %). Fishing effort is quite dispersed in the northern Gulf of Saint Lawrence, except in Îles-de-la-Madeleine and the Lower North Shore where it is rather concentrated. Îles-de-la-Madeleine landings, effort and catch per unit effort increased with the arrival of a relatively good recruitment pulse in 1993. Research data revealed that reproduction in 1990 and 1991 was somewhat unsuccessful. Projections based on the prerecruitment index and the index of abundance of post-larvae predict a slight increase in available biomass in 1994 compared to 1993. On the Gaspé peninsula the landing pattern for the last twenty years shows that the sea scallop stock is overexploited. The presence of a dominant mode of 80 to 90 mm scallops in 1993 may result in an increase in available biomass in 1994. However, with the absence of prerecruits this would probably be only a temporary increase. On the Upper North Shore fishing effort is far too intense for the population and the instability of catch rates reflects the uncertainty of these beds. The significant decrease in CPUE over the last few years indicates a gradual depletion of the population. On the Middle North Shore fishing effort has decreased since individual quotas were assigned in 1991. The situation here is clearly different from that in the other regions of Quebec. On the Middle North Shore stocks are relatively abundant and exploitation is still largely maintained by accumulated biomass. As well, in areas 16G, 16E and 18A there are still several virgin beds of high scallop densities but which may have slow growth. On the Lower North Shore a progressive increase in size, the absence of young, and a massive mortality of sea scallops are disturbing. Fishing effort clearly surpasses the reproductive capabilities of the population. Exploratory fishing in 1993 in areas 15, 18C and 18D indicated the Island scallop was usually present over the whole territory but in weak abundance. An analysis of meat yield in relation to scallop whole weight (conversion factor) was carried out for the northern Gulf and the results indicated much variability both interspecific and intraspecific. The mean conversion factor is approximately 7.8 for the sea scallop and 6.6 for the Island scallop.