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Bibliography of the Maurice Lamontagne Institute

Louise GENDRON

GENDRON, L., 2010. Rock crab of the coastal waters of Quebec in 2009. DFO, Canadian Science Advisory Secretariat, Science Advisory Report, 2010/010, 14 p .

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GENDRON, L, G. SAVARD, 2010. Évaluation de l’état des stocks de crabe commun (Cancer irroratus) des eaux côtières du Québec en 2009 ; Assessment of Rock crab (Cancer irroratus) stock status in the coastal waters of Québec in 2009. MPO, Secrétariat canadien de consultation scientifique, Document de recherche ; DFO, Canadian Science Advisory Secretariat, Research Document, 2010/069, 70 p .

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begin to take off until 1995, first in the southern part of the Gaspé Peninsula and Magdalen Islands, then along the north shore of the Gaspé Peninsula and, since 2004, on the North Shore and Anticosti Island. It is common knowledge that rock crab is an important prey species for lobster. Thus, as soon as rock crab exploitation began, the fishery was managed by a conservation plan intended to protect the trophic relationships between these two species. The management measures currently in place are for protecting the reproductive potential by keeping exploitation rates low or moderate. The present research document describes the data and analyses that served to determine stock status and provide recommendations for the 2010-2012 fishing seasons (MPO 2010). Stock assessment is based mainly on the review of abundance indicators (landings and catch rates) and demographic indicators (size of crabs landed), from the commercial fishery. The assessment was based on examination of historical trends highlighting the changes observed since the last stock assessment in 2006 (MPO 2007). Additionally, incidental catches of rock crab from a survey on lobster conducted since 1995 in the Magdalen Islands was used to estimate recruitment. A trap survey was also conducted in July 2008 along the north shore of the Gaspé Peninsula to follow the evolution of rock crab populations in exclusion (no-take) areas, in comparison with adjacent fishing areas. The development of the rock crab fishery in the Gaspé Peninsula and Magdalen Islands in the past fifteen years has been done in a cautious manner. In 2009, in general, stock status indicators suggest that up to now, harvesting levels are not causing any major problems for populations. In a few cases, such as in the Magdalen Islands and on the North Shore, small reductions in quotas or fishing effort were recommended in order not to accentuate observed declines in CPUEs, or decreases in mean size or in the number of large-size crabs. However, the management objectives of maintaining moderate harvesting levels are threatened by a lack of control of the by-catches by lobster vessels. In addition, the directed fishery effort currently deployed is significantly lower than that permitted by the existing management measures. The deployment of latent effort would increase the exploitation rate, with unknown consequences on the stability observed until now. Recommendations were given to eliminate this latent effort.

GENDRON, L., E. TAMIGNEAUX, C. LEROUX, M.-J LEBLANC, 2010. Ajustements du calendrier de culture de la laminaire à long stipe (Saccharina longicruris) en Gaspésie (Québec) pour éviter la colonisation des frondes par le bryozoaire Membranipora membranacea et augmenter le nombre de récolte annuelles. Rapp. can. ind. sci. halieut. aquat., 284, 54 p .

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Until recently, cultivation trials of the algae Saccharina longicruris conducted in the Baie-des-Chaleur only aimed at one production cycle per year, from April to November. During those trials, colonisation of fronds by the bryozoa Membranipora membranacea caused considerable damages to the algae. The present study aimed to determine if shifting the production cycle in order to avoid cultures during the summer (July and August) can reduce damages caused by the infestation of the thalli by bryozoans. At the same time, the possibility of obtaining potentially interesting yields from three production cycles per year (fall, winter and spring cycles) was tested. Results indicate that the short production cycles did not provide sufficient harvest volume. However, starting the cultures in late fall and harvesting the algae in early July of the following year (production cycle of 8-10 months) could be the best production strategy for S. longicruris, with yields in the order of 3.3 kg per meter of longline rope, composed of large algae (frond = 1m) with a nice appearance and free from bryozoans.

ÉMOND, K., B. SAINTE-MARIE, L. GENDRON, 2010. Relative growth, life-history phases, and sexual maturity of American lobster (Homarus americanus). Can. J. Zool., 88: 347-358 .

Previous studies of relative growth in crustaceans have focused primarily on body parts representing sexual characters for the purpose of determining size at onset of sexual maturity. We have revisited the relative growth of abdomen and crusher claw in American lobster (Homarus americanus H. Milne Edwards, 1837) in a general life-history perspective using a broad spectrum of lobster sizes (6–160 mm cephalothorax length (CL)). Growth phases were recognized by inflections in scatterplots of a body-part measurement against CL. The abdomen is characterized by three growth phases in the male and female, whereas the crusher claw has at least three growth phases in the male and at least two in the female. Additionally, we explored relative growth of gonopod and vas deferens for males of 35–150 mm CL. Both organs exhibit a synchronous change from strong to weak positive growth allometry. The growth phases can be associated with major life-history events including the transition from a cryptic to an overt lifestyle and the onset of physiological, functional, and morphometric maturity. The onset of morphometric maturation inferred from relative growth of abdomen and crusher claw precedes functional maturity in females and follows it in males©2010 National Council Research Canada

GENDRON, L., 2010. Le crabe commun des eaux côtières du Québec en 2009. MPO, Secrétariat canadien de consultation scientifique, Avis scientifique, 2010/010, 14 p .

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GENDRON, L., Y. GRÉGOIRE, 2009. Évaluation de l’efficacité de deux types de casiers à homard utilisés aux Îles-de-la-Madeleine en 2008. Rapp. tech. can. sci. halieut. aquat., 2834, 52 p .

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In recent years, lobster fishers started to use a trap having the same dimension as the traditional hemicylindric trap, but having a square rather than round shape, and with a volume up to 20 % greater. Observations on the yield of these new traps were made during the 2008 fishing season, on Grande-Entrée, Millerand and Grosse Isle fishing grounds, at the beginning, middle and end of the season. A total of 54 fishing trips were sampled during the season on six boats (two per fishing ground). Over 11 000 lobsters were caught with 3 744 traditional and 2 931 rectangular traps. For the whole fishing season, the rectangular traps caught more commercial-size lobsters than the traditional traps, by a factor of 1.06, 1.09 and 1.22 for Grande-Entrée, Millerand and Grosse Isle, respectively. The differences were greater when the catch rates were higher, mainly at the beginning of the season. Although the rectangular traps tested had a greater volume (13-20 %) than the traditional trap, no clear relationship could be established between yields and trap volume. The use of rectangular traps can contribute to an increase in fishing effort and may provide an advantage to its user, in the context of a competitive fishery.

GENDRON, L., 2009. Évaluation des populations de homard en Gaspésie (ZPH 19, 20 et 21) en 2008. MPO, Secrétariat canadien de consultation scientifique, Avis scientifique, 2009/017, 14 p .

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GENDRON, L., 2009. Assessment of lobster stocks of the Magdalen Island (LFA 22) in 2008. DFO, Canadian Science Advisory Secretariat, Science Advisory Report, 2009/013, 13 p .

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GENDRON, L., 2009. Assessment of lobster stocks of the Gaspé (LFAs 19, 20 and 21) in 2008. DFO, Canadian Science Advisory Secretariat, Science Advisory Report, 2009/017, 13 p .

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GENDRON, L., P. OUELLET, 2009. Egg development trajectories of early and late-spawner lobsters (Homarus americanus) in the Magdalen Islands, Québec. J. Crust. Biol., 29(3) : 356-363 .

This study examines egg development in American lobster (Homarus americanus) ovigerous females caught off the Magdalen Islands (MI), Québec, in September 2002 and kept in tanks for 10-11 months under a simulated natural temperature cycle. The study compares egg development trajectories of 7 early-spawners (ES) that had a well-defined pigmented eye area (Perkins eye index, PEI: 190-246 μm) at the time of capture and 8 late-spawners (LS) with no visible pigmented eye at the time of capture. Eggs from ES achieved about 80 % of their development in the fall, followed by a circa 6-months rest period. Eggs from LS reached approximately 50 % development by late fall, and unlike eggs from ES, continued development during winter even at temperatures of 1.0-1.5 °C. The two groups experienced different numbers of effective (>3.4 °C) degree-days (ES: 1440.7, LS: 1308.0) for complete embryonic development and late spawning translated into late hatching. Additional observations made on a group of 72 ovigerous MI females caught in September 2006 indicate that early spawning is mainly associated to larger females, most likely multiparous, with a 2-year reproductive cycle, and late spawning mainly to smaller females, most likely primiparous, with a 1-year cycle, molting and spawning the same year. Larvae from ES/ multiparous and LS/primiparous may therefore encounter different environmental conditions for survival at hatching and during larval development. The occurrence of females having different patterns of egg development trajectories in American lobster populations can help spread larval production over time. This can be viewed as a mechanism for coping with environmental uncertainty.©2009 The Crustacean Society

GENDRON, L., SONIA DUBÉ, 2009. Évaluation des stocks de mactre de Stimpson des eaux côtières du Québec, 30 janvier 2009, Institut Maurice-Lamontagne ; Stock assessments on Stimpson's surfclam in the Quebec's inshore waters, January 30, 2009, Maurice Lamontagne Institute. MPO, Secrétariat canadien de consultation scientifique, Série des comptes rendus ; DFO, Canadian Science Advisory Secretariat, Proceedings Series, 2009/010, 14 p .

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This document contains the proceeding from the meeting held within the regional assessment process on Stimpson’s surfclam stocks in Quebec’s inshore waters following the 2006 to 2008 fishing season. This review process was held on January 30, 2009 at the Maurice Lamontagne Institute in Mont-Joli. This meeting gathered fiftheen participants from sciences. During this meeting, the assembly reviewed the status of the Stimpson’s surfclam stocks commercially exploited in the Quebec Region. Therefore, this proceeding contains the essential parts of the presentations and discussions held and relates the main recommendations and conclusions that were presented during the review

GENDRON, L., 2009. Évaluation des populations de homard de la Côte-Nord (ZPH 15, 16 et 18) et de l'île d'Anticosti (ZPH 17) en 2008. MPO, Secrétariat canadien de consultation scientifique, Avis scientifique, 2009/047, 11 p .

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GENDRON, L., 2009. Assessment of the lobster populations of the North Shore (LFAs 15, 16 and 18) and Anticosti Island (LFA 17) in 2008. DFO, Canadian Science Advisory Secretariat, Science Advisory Report, 2009/047, 11 p .

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GENDRON, L., 2009. Évaluation des populations de homard aux Îles-de-la-Madeleine (ZPH 22) en 2008. MPO, Secrétariat canadien de consultation scientifique, Avis scientifique, 2009/013, 13 p .

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GENDRON, L., É. TAMIGNEAUX, 2008. Expériences de culture de l’algue brune Saccharina longicruris en 2007 : essais en bassin et en mer au large de Paspébiac et de Grande-Rivière (Québec). Rapp. tech. can. sci. halieut. aquat., 2820, 58 p .

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The cultivation experiments of the brown alga Saccharina longicruris were pursued in 2007 for a second consecutive year. The work carried out was planned to take into account the recommendations put forward after the 2006 trials. The objectives were to 1) examine if growth of small plants (5 mm) during the phase of tank cultivation was faster at low density; 2) modify the cultivation schedule to avoid frond colonization by the invasive bryozoan Membranipora membranacea; 3) determine if the occurrence of the bryozoan is recurrent in Paspébiac; 4) study the effect of depth of culture on yields in Paspebiac and 5) undertake an experiment of kelp cultivation in Grande-Rivière to compare yields with those of Paspébiac and examine if the invasive bryozoan is present and affects algae as it does in Paspébiac. The 2007 study showed that a reduction of the density of small plants during the tank cultivation phase had a significant positive effect on their size. After a period of three months, the algae grown at low density (3 to 10 times less than the control density) were significantly larger (up to nearly twice). Reaching larger sizes faster could accelerate the transfer at sea, reducing the time and the costs of the tank cultivation phase. In 2007, the transfer of algae at sea was done a few weeks earlier than in 2006. Results suggest that cultivation at sea starting in April and ending in August could help obtain interesting yields. It is however necessary to better explore different temporal schedules that could be adjusted to better benefit from a period of fast growth in spring while avoiding colonisation and destruction of the algae by the bryozoan during the summer months. As in 2006, the bryozoan caused damages to the algae in Paspebiac. Algae in Grande-Rivière were also affected. The bryozoan colonizes the algae in surface as well as in deeper (11 meters) waters. However, algae in deeper waters are less subjected to water turbulence and the impact of bryozoans on plant survival is delayed. Preliminary observations of the effect of depth on algal cultivation suggest that it could be beneficial to set longlines at depths greater than five meters. Besides having good growth rates and high yields, this strategy could help reduce frond erosion, breakage and detachment of fronds caused by surface water turbulence, and to reduce risks that the algae be subjected to less favourable temperature and salinity conditions more susceptible to occur in surface waters. The two sites studied have relatively similar environmental conditions favourable for kelp culture. The reduction of nitrogen salts during summer causes however a temporary slowing of growth.

HARDY, M., L. GENDRON, P. ARCHAMBAULT, 2008. Distribution spatio-temporelle du homard au large de Saint-Godefroi (baie des Chaleurs, Québec) et relation avec les activités de pêche au pétoncle. Rapp. tech. can. sci. halieut. aquat., 2781, p .

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This study was undertaken to examine the potential role of the scallop fishing activities in the reductions of lobster fishing yields observed in the area of Saint-Godefroi (lobster fishing sub-area 20B6, baie des Chaleurs, Quebec, Canada) since the end of the 1990s. Experimental fishing was carried out in 2002 and 2003 to first determine the spatial and bathymetric distribution of lobster in the area from July to October, and then to determine the extent and the moment of the seasonal movements from the shallow inshore waters towards the deeper offshore waters. A number of trends concerning the use of the area in relation to certain characteristics of the habitat (bottom temperature, substrate and benthic communities) were also observed. In general, lobster seems to inhabit preferentially habitats that are structurally more complex. The daily positions of the scallop fishing activities available over the 998-2006 period were used to evaluate the spatial and temporal overlap between scallop dredging activities and the St-Godefroi lobster population, fishing and habitat. Our results suggest that spatial and temporal overlap of scallop fishing activities and lobster is rather limited. Scallop fishing would therefore have little direct impact on the adult lobster population. It was possible from our study to identify important sites and habitats for the growth and the reproduction of lobster in this area. No dredging activities seem to take place in these habitats, therefore preserving their integrity. However, there is spatial overlap between scallop fishing and the habitat used by the lobster in fall, at the time of its migration into deeper waters. The indirect impacts of dredging (disturbance of the sediments, reduction of bottom complexity, changes in the communities) on a habitat used by lobster for transit during a period of reduced activity were not assessed in the course of this study but should be considered in future works.

GENDRON, L., G. SAVARD, 2008. Distribution et abondance des homards de grande taille en Gaspésie et impacts économiques et biologiques de l'instauration d’une taille maximale de capture. Rapp. can. ind. sci. halieut. aquat., 281, 43 p .

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A study was undertaken in 2004 to assess the economic impacts for the lobster fishers of the implementation of a maximum legal catch size and to examine the benefits of such a measure in terms of increase in egg production. To the request of the industry, three scenarios of maximum catch size (carapace length, CL) were examined: 120 mm (4.75 inches), 127 mm (5 inches) and 140 mm (5.5 inches). The assessments were based on the number of lobsters ≥ 120, ≥ 127 and ≥ 140 mm CL reported during the 2004 lobster fishing season in each lobster fishing sub-zones, from at-sea and plant sampling. Sampling was done between the 10 May and the 1st July 2004, from which 15555 and 13361 lobsters were sampled at-sea and in plants respectively. The two main elements that come out of this study are that the abundance of large lobsters is relatively low in the Gaspé and that these lobsters are not distributed homogenously throughout the area. Consequently, the benefits of the implementation of a maximum catch size, in terms of the increase in egg production would be marginal in the short term and could be significant only on a longer term (15 years). Because of the spatial heterogeneity in the distribution of large lobsters, the financial impact of this measure would not be shared evenly among fishermen.

GENDRON, L., 2007. Évaluation des stocks de crabe commun des eaux côtières du Québec en 2006. MPO, Secrétariat canadien de consultation scientifique, Avis scientifique, 2007/033, 12 p .

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GENDRON, L., P. GAUTHIER, G. SAVARD, 2007. Expériences préliminaires de culture de l’algue brune Laminaria longicruris en laboratoire et en mer au large de Paspébiac (Québec) en 2006. Rapp. tech. can. sci. halieut. aquat., 2731, 53 p .

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GENDRON, L., 2007. Assessment of rock crab stocks in the coastal waters of Quebec in 2006. DFO, Canadian Science Advisory Secretariat, Science Advisory Report, 2007/033, 12 p .

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GENDRON, L., 2006. Évaluation des stocks de homard de la Gaspésie (ZPH 19, 20 et 21) en 2005. MPO, Secrétariat canadien de consultation scientifique, Avis scientifique, 2006/004, 12 p .

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GENDRON, L., B. SAINTE-MARIE, 2006. Growth of juvenile lobster Homarus americanus off the Magdalen Islands (Quebec, Canada) and projection of instar and age at commercial size. Mar. Ecol. Prog. Ser., 326: 221-233 .

Juvenile American lobster Homarus americanus were quantitatively surveyed in the southeast Baie de Plaisance, Magdalen Islands, from 1995 to 2004. Lobster were collected by SCUBA, in summer and/or early fall after the annual settlement period. Growth for up to 3 yr following settlement was assessed by modal analysis of carapace length (CL)-frequency distributions and was confirmed for the first year by in situ rearing of Stage IV lobster collected from the plankton. In every sampling year, some modes (attributed to instars) were apparent in CL-frequency distributions up to 50 mm CL (estimated to be Instar XVI on average). The mean percent molt increment declined gradually from about 23% at Instar IV to about 15% at Instar XV. Strong year-classes could be tracked reasonably well for up to 2-3 yr after settlement. From this point, we projected growth to fishery recruitment and suggest that lobster reach commercial size at a higher instar and older age than previously believed. This is the first study to explain lobster juvenile growth in such detail, and it constitutes an essential step toward the understanding of potential settler-to-recruit relationships.© 2006 Inter-Research.

GENDRON, L., 2006. Assessment of the lobster stocks of the Magdalen Islands (LFA22) in 2005. DFO, Canadian Science Advisory Secretariat, Science Advisory Report, 2006/012, 12 p .

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GENDRON, L., 2006. Évaluation des populations de homard aux Îles-de-la-Madeleine (ZPH 22) en 2005. MPO, Secrétariat canadien de consultation scientifique, Avis scientifique, 2006/012, 12 p .

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GENDRON, L., 2006. Assessment of the lobster stocks of the Gaspé Peninsula (LFAs 19, 20, and 21) in 2005. DFO, Canadian Science Advisory Secretariat, Science Advisory Report, 2006/004, 12 p .

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GENDRON, L., 2005. Lobster in the Magdalen Islands (LFA 22) in 2004. DFO, Canadian Science Advisory Secretariat, Science Advisory Report, 2005/006, 9 p .

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GENDRON, L., 2005. Lobster on the North Shore (LFA 15, 16 and 18) and around Anticosti Island (LFA17) in 2004. DFO, Canadian Science Advisory Secretariat, Science Advisory Report, 2005/004, 8 p .

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GENDRON, L., 2005. Homard des Îles-de-la-Madeleine (ZPH 22) en 2004. MPO, Secrétariat canadien de consultation scientifique, Avis scientifique, 2005/006, 9 p .

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GENDRON, L., 2005. Homard de la Gaspésie (ZPH 19, 20AB, 21AB) en 2004. MPO, Secrétariat canadien de consultation scientifique, Avis scientifique, 2005/005, 9 p .

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GENDRON, L., 2005. Homard de la Cote-Nord (ZPH 15, 16 et 18) et de l'ile d'Anticosti (ZPH 17) en 2004. MPO, Secrétariat canadien de consultation scientifique, Avis scientifique, 2005/004, 8 p .

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GENDRON, L., 2005. Impact of minimum legal size increases on egg-per-recruit production, size structure, and ovigerous females in the American lobster (Homarus americanus) population off the Magdalen Islands (Quebec, Canada): A case study. N. Z. J. Mar. Freshwat. Res., 39 (Spec. Issue 2): 661-674 .

GENDRON, L., 2005. Lobster around the Gaspe Peninsula (LFAs 19, 20AB, 21AB) in 2004. DFO, Canadian Science Advisory Secretariat, Science Advisory Report, 2005/005, 9 p .

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GENDRON, L., G. SAVARD, N. PAILLE, 2004. État des stocks de homard de la Côte-Nord du Québec (Zones 15, 16 et 18) en 2003. MPO, Secrétariat canadien de consultation scientifique, Document de recherche, 2004/062, 48 p .

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In recent years, lobster landings from the North Shore accounted for 1 % to 2 % of total lobster landings in Quebec. Landings recorded in area 15 in 2003 totalled 30 t, which is equivalent to 2002 and to the 1984-1993 average (35 t). In area 16, landings totalled 8 t which is lower that the 1984-2002 average (13 t). Landings in area 18 are very low and have reached 2 t in 2003. Since 1993, the average annual CPUE observed during at-sea sampling in LFAs 15 and 16 ranged from 0.2 to 0.4 lobsters per trap. Mean CPUE recorded in 2003 reached 0.3 lobster per trap, which is slightly below the series average (0.33 lobster per trap). Mean size of commercial lobster was 87.5 mm in 2003 compared to 83.6 mm in 1997, before the increase in minimum legal size. Since 1998, minimum catch size was increased by 4 mm. Although size frequency distributions occasionally show a few modes in the larger size groups, they nevertheless indicate relatively high exploitation rates. No jumbo lobsters (≥127 mm CL) were found in samples in 2003. Over the years, berried females have been seen in catches, mainly at the end of the fishing season, in proportions that ranged from 5 % to 35 %. However, the abundance is generally low and between 1993 an 2003, an average of only 24 berried females was sampled each year. There was a slight increase in their proportion in the past three years. The average size of berried females is about 90 mm. Observations made in 2003 in LFA 15 showed that females reach sexual maturity at approximately 93 mm. Egg-per-recruit production was not calculated specifically for North Shore sectors. Nevertheless, because of the large size at sexual maturity and high exploitation rates, the egg production per recruit level is thought to be low compared with a non-harvested lobster stock. Consequently, it is recommended that minimum catch size continue to be increased, in order to increase egg production.

GENDRON, L., 2004. Lobster of the Inshore Waters of Quebec in 2003. Science, Stock Status Report, 2004/020, 14 p .

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FOGARTY, M. J., L. GENDRON, 2004. Biological reference points for American lobster (Homarus americanus) populations: limits to exploitation and the precautionary approach. Can. J. Fish. Aquat. Sci., 61: 1392-1403 .

Large-scale changes in American lobster (Homarus americanus) landings and abundance have been documented in both Canada and the United States over the last several decades. The spatial coherence of these changes suggests the importance of common environmental and fishery-related factors operating over broad areas in the western North Atlantic. Changes in both biotic and abiotic factors have been hypothesized to underlie the recent increases in lobster production. Area expansion of lobsters to previously unoccupied or low-density areas appears to be an important element of the population increase. Here, we review biological reference points applied to American lobster populations in the United States and Canada. Egg production per recruit models have been used to specify limit reference points (F10 % in the United States) or target reference points (increasing egg production per recruit to twice its 1995 level in Canada). Surplus production and yield-per-recruit models have also been employed to provide qualitative management guidelines. We describe sources of uncertainty in the development of biological reference points for American lobster based on dynamic pool models in relation to the precautionary approach. Finally we consider auxiliary indicators and reference points with potential application to lobster stocks.©2004 NRC Canada

GENDRON, L., 2004. Homard des eaux côtières du Québec en 2003. Rapport sur l'état des stocks, 2004/020, 14 p .

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GENDRON, L., G. SAVARD, N. PAILLE, 2004. Lobster stock status on the Quebec North Shore (LFAs 15, 16 and 18) in 2003. DFO, Canadian Science Advisory Secretariat, Research Document, 2004/062, 48 p .

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GENDRON, L., 2003. Lobster of the inshore waters of Quebec in 2002. Science, Stock Status Report, 2003/013, 16 p .

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GENDRON, L., 2003. Le homard des eaux cotieres du Quebec en 2002. Rapport sur l'état des stocks, 2003/013, 18 p .

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GENDRON, L., A.M. WEISE, M. FRECHETTE, P. OUELLET, C.W. McKINDSEY, L. GIRARD, 2003. Evaluation of the potential of cultured mussels (Mytilus edulis) to ingest state I lobster (Homarus americanus) larvae. Can. Ind. Rep. Fish. Aquat. Sci., 274, 20 p .

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In Quebec, mussel aquaculture is expanding rapidly and is being developed in areas where lobster is present and where lobster larvae are likely to be found. Lobster fishermen are concerned that mussel aquaculture could pose a threat to lobster larvae. They believe that cultured mussels may ingest or otherwise kill lobster larvae. The objective of this study was to evaluate the potential of cultured mussels (Mytilus edulis) to ingest stage I lobster (Homarus americanus) larvae and, if this does occur, determine whether this ingestion kills or other wise harms the larvae.

GENDRON, L., A.M. WEISE, M. FRECHETTE, P. OUELLET, C.W. McKINDSEY, L. GIRARD, 2003. Évaluation du potentiel des moules d’élevage (Mytilus edulis) à ingérer des larves de homard (Homarus americanus) de stade I. Rapp. can. ind. sci. halieut. aquat., 274, 20 p .

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In Quebec, mussel aquaculture is expanding rapidly and is being developed in areas where lobster is present and where lobster larvae are likely to be found. Lobster fishermen are concerned that mussel aquaculture could pose a threat to lobster larvae. They believe that cultured mussels may ingest or otherwise kill lobster larvae. The objective of this study was to evaluate the potential of cultured mussels (Mytilus edulis) to ingest stage I lobster (Homarus americanus) larvae and, if this does occur, determine whether this ingestion kills or other wise harms the larvae.

GENDRON, L., G. SAVARD, 2003. État des stocks de homard de la Gaspésie (Zone 19, 20 et 21) en 2002 ; Lobster stock status in the Gaspé (LFAs 19, 20 and 21) in 2002. MPO, Secrétariat canadien de consultation scientifique, Document de recherche ; DFO, Canadian Science Advisory Secretariat, Research Document, 2003/059, 54 p .

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In 2002, lobster landings in the Gaspé totalled 789 t, a decrease of 17 % from 2001 (959 t). Landings in 2002 were 14 % below the average for the 1990s and beginning of the 2000s (1990-2001), but 8 % above the 25-year average (1977-2001). In the Gaspé in 2002, 94 % of landings were from LFA 20, 4 % were from LFA 19 and 2 % were from LFA 21. <br>The decrease in landings in 2002 can be attributed to a cold fishing season which could have negatively impacted catchability. The 1-mm increase in minimum catch size can account for up to 10 % of the drop in certain sectors. The 2001 fall fishing season in 21B has taken part of the annual recruitment, which could explain the decrease in landings the following spring in this area. In 2002, the CPUE of commercial lobsters was 0.41 lobster/trap, its lowest level since 1986. It was 28 % below the average (in number) for 1986-2001 and 18 % below the weight average. Larger lobsters partly offset the decrease in the number of lobsters caught. CPUEs measured during the fall fishing season in 21B were on average seven times higher than in spring. Following the increases in minimum legal size, the mean size of lobsters landed in LFA 20 as a whole increased from 4-5 mm in 2002 compared with 1996, while mean weight rose by about 15 %. The proportion of "market" lobsters (greater than or equal 83 mm) was 82 % in 2002, compared with an average of 49 % for 1993-1996. The exploitation rate for commercial-size males reached 88 % in 2001 in LFA20. The increase in minimum catch size contributed to reduce to 60 % the exploitation rate for the portion of the stock greater than or equal 76 mm. In LFA 20, the proportion of jumbo lobster (greater than or equal 127 mm CTL) accounted for only 0.04 % of the catch (in number) in 2002. The mean size of lobsters in LFAs 19 and 21 is bigger than that of lobsters in LFA 20. More jumbo lobsters were also found there, accounting for 4.5 % and 1.6 % of the catch, respectively. The results of a simulation model show that with the 5-mm increase in minimum catch size, egg production per recruit (EPR) appears to have increased by approximately 90 % from 1996 levels. The objective of the conservation plan to double 1996 EPR levels will be reached with a minimum size of 82 mm. The abundance of berried females has increased in the population but egg production probably mainly comes from first spawners (primiparous). The conservation measures taken since 1997 have had a tangible, positive impact on lobster stocks. Egg production has increased and the growth potential of lobster is better expressed. Doubling egg production per recruit is the first step in meeting the conservation objectives that are also intended to ensure the distribution of egg production between first spawners and mulltiple spawners and to widen the size structure of stocks. Exploitation rates remain high and need to be reduced. Such high exploitation rates make the fishery heavily dependent on annual recruitment, offset the expected benefits of increasing the minimum catch size, and slow down the increase in the proportion of multiparous females in stocks.

GENDRON, L., G. SAVARD, 2003. État des stocks de homard aux Îles de la Madeleine (Zone 22) en 2002 ; Lobster stock status in the Magdalen Islands (LFA 22) in 2002. MPO, Secrétariat canadien de consultation scientifique, Document de recherche ; DFO, Canadian Science Advisory Secretariat, Research Document, 2003/058, 54 p .

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Lobster landings in the Magdalen Islands reached 2,024 t in 2002, compared with 2,177 t in 2001, representing a 7 % decrease. Landings were 4 % below the average of the years 1985-2001 (2,110 t), which include years where historic high levels of landings were recorded. In a longer term perspective, landings in 2002 were 12 % higher than the 25-year average (1977-2001) of 1,812 t. The 2002 fishing season was slightly colder than the preceding years, which may have had an effect on catchability. In 2002, the average CPUEs in number of lobster for the entire Magdalen Islands were 13 % below the series average (1985-2001), but in terms of weight of lobster, they were 2 % above the average. CPUEs in number were lower in 2002 compared to 2001 both in southern and northern Magdalen Islands. However, decreases of CPUEs in weight were a little less. The mean size of lobsters caught increased by approximately 5 mm in 2002 compared to 1996. In 2002, the proportion of "market" lobsters (≥ 83 mm) was > 90 %, compared with averages of 54 % (south) and 65 % (north) in 1996. The proportion of jumbo lobster (≥ 127 mm CL) remains very low (< 1 %). Exploitation rates for commercial-size male lobsters remain high in the southern and northern Magdalen Islands and are above 70 %. Exploitation rate of the fraction of the population ≥ 76 mm has decreased to approximately 45 % since the minimum catch size was increased. The results of a simulation model show that with the 6-mm increase in minimum catch size, egg production per recruit appears to have increased by approximately 75 % from 1996 levels. The objective of doubling egg production per recruit should be reached by increasing minimum catch size to 83 mm. The abundance of berried females has increased in the population but egg production probably mainly comes from first spawners (primiparous). The abundance indices of recruitment to the fishery suggest that current landing levels could be maintained in 2003. However, prerecruit and juvenile abundance indices were down during the trawl survey in 2002, suggesting a possible drop in fishing recruitment in the coming years. The conservation measures taken since 1997 have had a tangible, positive impact on lobster stocks. Egg production has increased and the growth potential of lobster is better expressed. Doubling egg production per recruit is the first step in meeting the conservation objectives that are also intended to ensure the distribution of egg production between first spawners and mulltiple spawners and to widen the size structure of stocks. Exploitation rates remain high and need to be reduced. Such high exploitation rates make the fishery heavily dependent on annual recruitment, offset the expected benefits of increasing the minimum catch size, and slow down the increase in the proportion of multiparous females in stocks.

GENDRON, L., J.-C. BRÊTHES, 2002. Simulations of the impact of different temporal and spatial allocations of fishing effort on fishing mortality in a lobster (Homarus americanus) fishery. Can. J. Fish. Aquat. Sci., 59: 899-909 .

A spatially explicit model is proposed to assess the impact on fishing mortality of modifying effort patterns for an American lobster (Homarus americanus) fishery. A two-box (offshore and inshore grounds) model is developed for the 1995 lobster fishery season in the Magdalen Islands (Quebec). It considers lobster migration and fisher's temporal and spatial effort dynamics to estimate within-season catchability patterns and exchange rates between the two spatial units. Different management scenarios are simulated: reducing nominal fishing effort and changing its temporal (season's length) and spatial (area closures) allocations. Catchability showed a strong temporal trend, being highest during the first 3 weeks and declining regularly afterwards. The model indicated a continuous migration toward the inshore during the fishing season and that a significant amount of biomass remained offshore. As a result, reducing fishing effort at the beginning of the season would have the greatest impact on exploitation rate. Allowing less effort in the offshore area would also reduce the exploitation rate significantly. Restricting effort to the inshore area, as it was 25 years ago, reduced substantially the exploitation rate. This model represents the first attempt to analyze in-season fishery dynamics and should be useful to further assess the impact of management measures.

GENDRON, L., 2002. Lobster of the inshore waters of Quebec in 2001. Science, Stock Status Report, C4-05, 13 p .

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GENDRON, L., 2002. Homard des eaux côtières du Québec en 2001. Rapport sur l'état des stocks, C4-05, 14 p .

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GENDRON, L., 2001. Homard des eaux côtières du Québec en 2000. Rapport sur l'état des stocks, C4-05, 15 p .

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GENDRON, L., P. GAGNON, 2001. Impact de différentes mesures de gestion de la pêche au homard (Homarus americanus) sur la production d'oeufs par recrue. Rapp. tech. can. sci. halieut. aquat., 2369, 31 p .

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A detailed model of the life cycle of the lobster from the Magdalen Islands and Gaspe populations, taking into account uncertainty in the input parameters arising from the difficulty in assessing their value or from their natural variability, was developed and used to assess the impact of new fishery regulations on the egg production per recruit (EPR). THe new regulations include additional limits on the legal sizes (minimum, maximum), reduction of the exploitation rate and increased protection of females by v-notching. Results of the calculations were used to develop the management plans put forward in the Quebec region since 1997, to double the EPR compared to the 1996 level. We also present a risk analysis concerning lobster fishing management, based on the probability of not reaching a given level of EPR.

PAILLE, N., L. GENDRON, 2001. Conception et mise en place de récifs artificiels pour le homard (Homarus americanus) : revue des essais et recommandations. Rapp. can. ind. sci. halieut. aquat., 261, 43 p .

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There is a growning interest for artificial reefs as they may represent a valid option to compensate for the loss or perturbation of lobster habitats. Building artificials reefs requires however a good knowledge of the biological characteristics and behavior of the target species, to be able to answer its needs and facilitate its establishment on the reef. Moreover a good knowledge of the surrounding environment is essential since the prevailing conditions will ultimately determine the performance and perennity of the reef. In this report, we describe 7 reefs that were built in the last 35 years. The purpose is to highlight the important aspects that should be taken into consideration in the future for the conception and deployment of artificial reefs for lobster. In the light of the examples, we present a discussion and some recommendations on the elements that should be addredded for the choice of the reef site, the building of the reef and for the performance evaluation, to determine if the initial goals were reached. Discussion on the choice of the reef site is based on the following six elements: the physical and chemical conditions on the site (temperature, salinity, oxygen, water and sediment contamination), the dynamics of prevailing water currents at small and large scales, the dynamincs of the substrate (erosion and sedimentation), the characteristics of the substrate, the site depth and the presence of conspecifics. The elements considered important for the conception and building of the reef that are discussed include the type of building material, the dimensions of the reefs and their spatial arrangement, the number, form, dimension and orientation of the shelters on the reef and the colonisation of the reef by other algal and animal species. The discussion on reef performance evaluation focuses on the variables to sample, the sampling techniques and strategies, and the sampling effort, depending on the type of reef, initial goals and the degree of precision required. It is certainly possible to build artificials reefs that are efficient for lobsters. These must provide a long-term suitable habitat adapted to the needs of the successive benthic stages of the lobster. The success of any artificial reef project relies on a responsible and effective planning and requires a scientifically rigourous assessment of reef performance in meeting its goal.

GENDRON, L., P. FRADETTE, G. GODBOUT, 2001. The importance of rock crab (Cancer irroratus) for growth, condition and ovary development of adult American lobster (Homarus americanus). J. Exp. Mar. Biol. Ecol., 262: 221-241 .

GENDRON, L., P. GAGNON, 2001. Impact of various fishery management measures on egg production per recruit in American lobster(Homarus americanus). Can. Tech. Rep. Fish. Aquat. Sci., 2369, 31 p .

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A detailed model of the life cycle of lobster populations from the Magdalen Islands and Gaspe, taking into account uncertainty in the input parameters arising from the difficulty in assessing their value or from their natural variability, was developed and used to assess the impact of new fishery regulations on the egg production per recruit (EPR). THe new regulations included additional limits on the legal sizes (minimum, maximum), reduction of the exploitation rate and increased protection of females by v-notching. Results of the calculations were used to develop the management plans put forward in the Quebec region since 1997, to double the EPR compared to the 1996 level. We also present a risk analysis concerning lobster fishing management, based on the probability of not reaching a given level of EPR.

GENDRON, L., 2001. Lobster of the inshore waters of Québec in 2000. Science, Stock Status Report, C4-05, 14 p .

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GENDRON, L., G. SAVARD, 2000. État des stocks de homard des eaux côtières du Québec en 1999 et suivi des impacts de l'augmentation de la taille minimale de capture. MPO, Secrétariat canadien pour l'évaluation des stocks, Document de recherche ; DFO, Canadian Science Advisory Secretariat, Research Document, 2000/115, 84 p .

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Québec lobster landings reached 292 t in 1999, compared with 3049 t in 1998 and 2825 t in 1997. They have been declining since the early 1990s. For the last three years, landings in the Magdalen Islands have remained stable at about 1900 t, but are 34 % below their 1992 peak. Gaspé landings were about 950 t, roughly the same as in 1998, and above the mean of the last 14 years (695 t). Landings on the North Shore dropped to 32 t and those of Anticosti Island to 89 t. In 1999, for the Magdalen Islands as a whole, catch rates held steady at 1998 levels, although on the north side they have been dropping constantly since 1992. In 1999, in the Gaspé, in LFAs 20A and 20B, catch rates were equivalent to those of 1998 and above the mean for the last 15 years. Catch rates in LFA 21 and on the North Shore (LFAs 15 and 16) remained stable in 1999, but were only half to a third of those in LFAs 20A and 20B. We have no figures on catch rates for LFA 17 (Anticosti), 18 (North Shore) and 19 (Northern Gaspé). In 1999, as a result of the increase in the minimum legal size, the mean size of lobster caught was about 3 mm longer than in 1996 in the Magdalen Islands and the Gaspé and about 2 mm longer on the North Shore. Exploitation rates remained high in the Magdalen Islands (about 70 %), the Gaspé (about 75 %) and probably on the North Shore, as well. They have been increasing since 1985, highlighting the fishery’s dependency on annual recruitment. The exploitation rate was lower on Anticosti Island (about 20 %). Since the legal size limit was raised 3 mm, computer modelling suggests that E/R has increased 26 % in the Magdalen Islands and 40 % in the Gaspé over 1996 levels. The goal is a 100 % increase. Recruitment indices were up in the Magdalen Islands and in the Gaspé, which suggests that landings in 2000 could be comparable to those of 1999. However, precision of the recruitment indices still needs to be improved, to increase the reliability of the predictions.

GENDRON, L., R. CAMIRAND, J. ARCHAMBAULT, 2000. Knowledge-sharing between fishers and scientists : towards a better understanding of the status of lobster stocks in the Magdalen Islands. Pages 56-71 in B. Neis & L.F. Felt (ed.). Finding our sea legs : linking fishery people and their knowledge with science and management. ISER Book, St. John's, Newfoundland .

GENDRON, L., 2000. Lobster of the inshore waters of Québec in 1999. Science, Stock Status Report, C4-05, 10 p .

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GENDRON, L., 2000. Le homard des eaux côtières du Québec en 1999. Rapport sur l'état des stocks, C4-05, 11 p .

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GENDRON, L., 1999. Lobster of the inshore waters of Québec in 1999. Science, Stock Status Report, C4-05, 13 p .

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GENDRON, L., 1999. Le homard des eaux côtières du Québec. Rapport sur l'état des stocks, C4-05, 15 p .

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GENDRON, L. (éd.), 1998. Proceedings of a workshop on lobster stock enhancement held in the Magdalen Islands (Québec) from October 29 to 31, 1997. Can. Ind. Rep. Fish. Aquat. Sci., 244, 135 p .

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A workshop on lobster stock enchancement was held in the Magdalen Islands, from october 29 to 31, 1997, at the request of the Association des pêcheurs propriétaires des Îles-de-la-Madeleine (APPIM). Through this workshop, the directors of APPIM wanted to learn about the very latest techniques of larval rearing and the production and seeding of juveniles on natural bottom areas or artificial reefs, and have first-hand accounts from experts regarding problems encountered, the solutions adopted and the pitfalls to avoid. The APPIM would like to stabilize lobster catches in the Magdalen Islands by relying on stock enhancement. Experts from United Kingdom, Ireland, France and Norway gave an overview of stock enhancement programs of the European Lobster (Homarus Gammarus) and experts from North America (Canada and USA) presented the work done with the American Lobster (Homarus americanus). Scientists from Québec presented the current knowledge on lobster stocks in the Magdalen Islands and afterwards, the APPIM gave an overview of its projects, which was then the focus of general discussions. The presentations and discussions gave and update on many technical issues and brought the participants to take a critical look at stock enhancement in an effort to delineate the potential benefits and understand the associated risks and impacts. The knowledge gained from the workshop will enable APPIM to define and develop a well-designed, realistic, and attainable project that can generate maximum benefits in the medium and long term for the industry and for the Magdalen Islands community.

GENDRON, L., 1998. Rock crab of the inshore waters of Québec. Science, Stock Status Report, C4-02, 8 p .

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GENDRON, L., 1998. Le crabe commun des eaux côtières du Québec. Rapport sur l'état des stocks, C4-02, 9 p .

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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.

GENDRON, L., 1998. Status of the Magdalen Islands lobster (Homarus americanus) stock and conservation strategy. Pages 95-99 in L. Gendron (ed.). Proceedings of a Workshop on Lobster Stock Enhancement held in the Magdalen Islands (Québec) from October 29 to 31, 1997. Dept. of Fisheries and Oceans (Can. Ind. Rep. Fish. Aquat. Sci., 244) .

GENDRON, L., 1998. Lobster of the inshore waters of Québec. Science, Stock Status Report, C4-05, 12 p .

GENDRON, L. (éd.), 1998. Compte-rendu d'un atelier de travail sur l'ensemencement des stocks de homard, tenu aux Îles-de-la-Madeleine (Québec) du 29 au 31 octobre 1997. Rapp. can. ind. sci. halieut. aquat., 244, 143 p .

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A workshop on lobster stock enchancement was held in the Magdalen Islands, from october 29 to 31, 1997, at the request of the Association des pêcheurs propriétaires des Îles-de-la-Madeleine (APPIM). Through this workshop, the directors of APPIM wanted to learn about the very latest techniques of larval rearing and the production and seeding of juveniles on natural bottom areas or artificial reefs, and have first-hand accounts from experts regarding problems encountered, the solutions adopted and the pitfalls to avoid. The APPIM would like to stabilize lobster catches in the Magdalen Islands by relying on stock enhancement. Experts from United Kingdom, Ireland, France and Norway gave an overview of stock enhancement programs of the European Lobster (Homarus Gammarus) and experts from North America (Canada and USA) presented the work done with the American Lobster (Homarus americanus). Scientists from Québec presented the current knowledge on lobster stocks in the Magdalen Islands and afterwards, the APPIM gave an overview of its projects, which was then the focus of general discussions. The presentations and discussions gave and update on many technical issues and brought the participants to take a critical look at stock enhancement in an effort to delineate the potential benefits and understand the associated risks and impacts. The knowledge gained from the workshop will enable APPIM to define and develop a well-designed, realistic, and attainable project that can generate maximum benefits in the medium and long term for the industry and for the Magdalen Islands community.

GENDRON, L., 1998. Le homard des eaux côtières du Québec. Rapport sur l'état des stocks, C4-05, 13 p .

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GENDRON, L., 1997. Le homard des eaux côtières du Québec. Rapport sur l'état des stocks, C4-05, 10 p .

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GENDRON, L., J. ARCHAMBAULT, 1997. Change in fishing capacity in the American lobster (Homarus americanus) fishery of the Magdalen Islands (Quebec) from 1975 to 1995. Can. Tech. Rep. Fish. Aquat. Sci., 2189, 16 p .

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Lobster landings rose steadily between the mid-1970s and the early 1990s both in the Magdalen Islands and on the Atlantic coast as a whole. A number of hypotheses have been advanced to explain this increase. Aside from certain environmental factors that may have favoured lobster recruitment, it has also been postulated that the increase in catches may be partly attributable to an increase in the fleet's fishing capacity. To describe the changes made in fishing equipment and practices since the mid-1970s, we interviewed 40 fishers from the 12 fishing wharves in the Magdalen Islands. Since 1975, the 325 Magdalen Islands fishers, each of whom operates 300 lobster traps during the nine-week fishing season, have boosted their harvesting capacity substantially. Changes made to fishing vessels (size, engine power, sturdiness), and the use of electronic navigation systems and colour sounders have made lobster fishers much more mobile than before, leading to a shift in harvesting strategy from interception to pursuit of the resource. Traps have also been modified (size, weight, entrance rings, proportions, design) as have the methods employed in operating these more efficient traps (organization of traps on lines, strategic positioning), thereby contributing to higher catch rates. All of these changes occurred during a period that coincided with rising landings. The expansion in the area harvested and the adoption of a strategy of pursuit have certainly contributed to the upward trend in catches.

GENDRON, L., J. ARCHAMBAULT, 1997. Évolution de la capacité de pêche au homard américain (Homarus americanus) aux Îles-de-la-Madeleine (Québec) au cours de la période 1975-1995. Rapp. tech. can. sci. halieut. aquat., 2189, 16 p .

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Lobster landings rose steadily between the mid-1970s and the early 1990s both in the Magdalen Islands and on the Atlantic coast as a whole. A number of hypotheses have been advanced to explain this increase. Aside from certain environmental factors that may have favoured lobster recruitment, it has also been postulated that the increase in catches may be partly attributable to an increase in the fleet's fishing capacity. To describe the changes made in fishing equipment and practices since the mid-1970s, we interviewed 40 fishers from the 12 fishing wharves in the Magdalen Islands. Since 1975, the 325 Magdalen Islands fishers, each of whom operates 300 lobster traps during the nine-week fishing season, have boosted their harvesting capacity substantially. Changes made to fishing vessels (size, engine power, sturdiness), and the use of electronic navigation systems and colour sounders have made lobster fishers much more mobile than before, leading to a shift in harvesting strategy from interception to pursuit of the resource. Traps have also been modified (size, weight, entrance rings, proportions, design) as have the methods employed in operating these more efficient traps (organization of traps on lines, strategic positioning), thereby contributing to higher catch rates. All of these changes occurred during a period that coincided with rising landings. The expansion in the area harvested and the adoption of a strategy of pursuit have certainly contributed to the upward trend in catches.

GENDRON, L., 1997. Lobster of the inshore waters of Québec. Science, Stock Status Report, C4-05, 9 p .

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GENDRON, L., 1996. Québec lobster. DFO, Atlantic Fisheries, Stock Status Report, 96/3, 10 p .

GENDRON, L., 1996. État des stocks de homard des côtes du Québec en 1995 et analyse des mesures de conservation. MPO, Pêches de l'Atlantique, Document de recherche, 96/123, 55 p .

Lobster landings in Québec in 1995 were up by 6.5 % compared with the previous year, increasing from 2,982 t in 1994 to 3,177 t in 1995. This situation contrasts with that of 1994, when landings dropped by 18 % compared with the year before. In the Magdalen Islands, the catch increased by 4.6 % from 2,007 t in 1994 to 2,099 t in 1995. Landings in the Gaspé rose substantially, i.e. by 18 %, from 806 t in 1994 to 951 t in 1995. In 1995, in the Magdalen Islands, CPUE values were fairly high (1.44 lobsters/trap/day) at the beginning of the 1995 seasonand as in previous years, they declined as the fishing season. CPUE recorded two weeks before the end of the season was 3.5 times lower (0.42 lobsters/trap/day) than early in the season, indicating a decline in the number of lobsters available to the fishery. In the Gaspé, CPUE values at the beginning of the fishing season (1.13 lobsters/trap/day) were twice as high as the previous year (0.55 lobster/trap/day) and much higher than the levels observed since 1988. Temperatures at the beginning of the 1995 season were warmer than the year before (around 3 °C), which might partly explain the higher catch rates. The catch rates on the North Shore were much lower than in other regions and comparable to those recorded late in the season in the Gaspé and the Magdalen Islands. In 1994, the exploitation rate in the southern Magdalen Islands was 69 % compared with 52 % in the northern section. Between 1985 and 1994, average exploitation rates in these two sectors were 64 % and 53% respectively. As a rule, exploitations rates higher in the Gaspé, where they averaged 73% between 1986 and 1994. The exploitation rate observed in the Gaspé in 1994, i.e. 67 %, was the lowest recorded since 1986. In 1995, the number of pre-recruits in traps was higher than in 1995 in the Magdalen Islands and in the Gaspé compared to 1994. Based on these observations, increases in landings in 1996 could be expected. The Fisheries Resource Conservation Council (FRCC) tabled a report on lobster conservation in November 1995 in which several measures for achieving the target egg per recruit production level of 5 % of an unfished stock were proposed. These include increasing the minimum legal size, marking berried females (V-notch), setting a maximum legal size, reducing exploitation rates, closing fishing areas and using more selective traps. FRCC also proposed that the choice of conservation measures should be left to the industry. Egg production per recruit has been calculated for lobster stocks in the Gaspé and the northern and southern parts of the Magdalen Islands in order to assess the efficiency of each measure proposed by FRCC. These data should help the industry to guide their choices in order to achieve the conservation goals.

GENDRON, L., 1996. Le crabe commun du Québec. MPO, Pêches de l'Atlantique, Rapport sur l'état des stocks, 96/5, 7 p .

GENDRON, L., 1996. Québec rock crab. DFO, Atlantic Fisheries, Stock Status Report, 96/5, 7 p .

GENDRON, L., 1996. Le homard du Québec. MPO, Pêches de l'Atlantique, Rapport sur l'état des stocks, 96/3, 11 p .

GENDRON, L., J.-P. DALLAIRE, G. SAVARD, 1995. Lobster on the Québec coast (fishing areas 15 to 22). Pages 27-54 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) .

GENDRON, L., J.-P. DALLAIRE, G. SAVARD, 1995. Homard des côtes du Québec (zones de pêche 15 à 22). Pages 28-56 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) .

GENDRON, L., P. FRADETTE, 1995. Revue des interactions entre le crabe commun (Cancer irroratus) et le homard américain (Homarus americanus), dans le contexte du développement d'une pêche au crabe commun au Québec. Rapp. manus. can. sci. halieut. aquat., 2306, 47 p .

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In the past few years, significant efforts have been made in the Quebec region to develop the exploitation of rock crab (Cancer irroratus). However, a number of fishermen have expressed concerns on the development of this new fishery because they fear that it could affect the lobster resource. The present document reviews the relationships between rock crabs and lobsters in order to better understand the linkage between these two species. The positive and negative impacts that the lobster resource could be subjected to following the exploitation of rock crab are discussed. Negative impacts could be expected only if the number of small crabs, i.e. those on which lobster feed, would be reduced to a level where they would become less available to the lobster. If the case arises, the growth and reproduction of lobster could be slower. Feeding on other prey may not compensate totally the absence of a high-quality prey such as rock crab. Moreover, it is possible that the predators feeding mainly on crustaceans, may increase their predation pressure on lobster. It is however not possible to determine the level of rock crab abundance under which this resource would become limiting and would cause the effects mentioned above. It is not possible neither to determine the level of parental stock abundance necessary to maintain sufficient production of small crabs. Rock crab and lobster interact sufficiently enough to justifiy a tight and cautions management of the rock crab resource, in order to prevent any negative impacts.

LAMBERT, J.-D., L. GENDRON, 1994. Whelk on the Québec coast (fishing areas 1 to 15). Pages 71-81 in L. Savard (ed.). Status report in 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) .

GENDRON, L., C. CYR, 1994. Distribution bathymétrique et saisonnière du crabe commun (Cancer irroratus) au large de l'Anse-à-Beaufils, Québec. Rapp. tech. can. sci. halieut. aquat., 2014, 53 p .

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The distribution of rock crab along the coast of Québec was studied to determine its seasonal pattern of migration. More specifically, we wanted to examine the hypothesis that the rock crab migrates seasonnally, first concentrating is shallow water in spring, then dispersing during summer. Sampling was done in 1991 off Anse-à-Beaufils, Québec, during the months of April, August, September and October. Additional observations were made during spring, off Carleton, Ste-Marie-sur-mer and Caraquet. Sampling was done using conical japanese traps. Samples were also obtained using a beam trawl and by SCUBA diving. In spring, rock crabs are mainly found in shallow water (10 m), on soft substrates, where they have apparently spent the winter. In summer, rock crabs appear to migrate to greater depths, possibly deeper than 40 m. Rock crabs would return to shallow water in fall where they seem to concentrate until the next spring. Their presence from fall until spring on soft substrates could be advantageous. Burying themselves in could provide protection for rock crab during their molting period. Although rock crab densities were lower in Ste-Marie-sur-mer and Caraquet when compared to Anse-à-Beaufils, we noticed that the highest concentrations of rock crab were again associated with soft substrates (sand-mud), and were generally in shallow water. The dispersal of rock crabs during summer could be conditionnel by a process of avoidance of warm water (> 12 °C). Also, after the molting period, the requirement for a soft substrate would be less. In summer, rock crabs are found on various type of substrates, apparently in accord with their availability and accessibility. These observations add to our knowledge of the nature and dynamics of rock crab along our coasts. Knowledge of the distribution patterns for rock crab, on which depends directly the yield of a fishery, will help users of this resource better plan their fishing activities.

GENDRON, L., S. ROBINSON (ed.), 1994. The development of underutilized invertebrate fisheries in Eastern Canada : workshop proceedings, Moncton, New Brunswick, 23-25 November 1993. Can. Manuscr. Rep. Fish. Aquat. Sci., 2247, 129 p .

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A workshop was held from November 23 to 25, 1993 in Moncton, New Brunswick. The specific objectives of the meeting were to examine the approaches to research and management of underutilized species in each DFO Region of eastern Canada, to examine the ongoing research activities for various groups of invertebrate species and to discuss the possibility of establishing some general guidelines for a rational and controlled development of fisheries for underutilized species. A total of 17 presentations were given in 5 sessions : (1) management and research approaches; (2) case studies - Crustaceans; (3) case studies - Molluscs and Echinoderms; (4) biological and sociological concerns in the development of new fisheries; and (5) a final round table discussion on guidelines and recommendations for the development of new fisheries.

GENDRON, L., C. CYR, P. FRADETTE, 1994. Détermination du potentiel de pêche au homard (Homarus americanus) le long du versant nord de la péninsule gaspésienne. Rapp. tech. can. sci. halieut. aquat., 1980, 35 p .

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Exploratory fishing took place during the summer of 1993 in the Gaspé-Nord region, between Capucins and Gros Morne, to determine if there were lobster concentrations large enough to sustain a commercial exploitation, and to determine the type of fishing that could be practiced. The exploratory fishing took place from July 5 to August 7, 1993. At first, fishing proceeded along predetermined transects. Then, fishermen were allowed to fish wherever they wished inside the designated zones. During the first phase of the exploratory fishing 8 lobsters were caught in a total of 1229 traps. During the second phase, 216 lobsters were caught for 3381 traps hauled. Most lobsters were caught in shallow water (3,6 to 10 m depth) inside zone 5 (Rivière-à-Claude to Gros Morne). Lobsters were large (95,0 and 97,7 mm CTL on average for females and males, respectively). In general, lobster biomass in this region is very low, growth is presumably slow and the reproductive potential low. The presence of a few small lobsters (60 mm CTL) suggests that there could be local recruitment of young lobsters. Local larval production however is probably exported. Therefore, the local stock is probably dependent on the production originating from other regions, either via larval transport or migration of individuals in the benthic stage. Our results suggest that lobster exploitation in this region would produce small yields and be of short duration if the recruitment is sporadic or slow. The establishement of conservation measures to protect the reproductive potential is questionable. First, the reproductive capability of the lobster population of Gaspé-Nord has not been demonstrated and second, such measures would not have any local impact. They would only benefit to populations that are dependent on the Gaspé-Nord population, which are unlikely to exist.

GENDRON, L., 1994. Homard des côtes du Québec (zones de pêche 15 à 22). Pages 24-45 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) .

GENDRON, L., 1994. Lobster on the Québec coast (fishing areas 15 to 22). Pages 21-39 in L. Savard (ed.). Status report in 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) .

GENDRON, L., P. FRADETTE, 1994. A review of the interactions between rock crab Cancer irroratus and lobster Homarus americanus and examination of the possible impacts of rock crab fishing on lobster resource. Pages 45-51 in L. Gendron & S. Robinson (ed.). The development of underutilized invertebrate fisheries in eastern Canada. DFO (Can. Manus. Rep. Fish. Aquat. Sci., 2247) .

GENDRON, L., L. SAVARD, D. BOISVERT, J.-M. NADEAU, 1994. Overview of the development of underutilized species fisheries in the Québec Region. Pages 13-17 in L. Gendron & S. Robinson (ed.). The development of underutilized invertebrate fisheries in eastern Canada. DFO (Can. Manus. Rep. Fish. Aquat. Sci., 2247) .

LAMBERT, J.-D., L. GENDRON, 1994. Buccin des côtes du Québec (zones de pêche 1 à 15). Pages 81-92 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) .

GENDRON, L., J.-P. DALLAIRE, G. SAVARD, 1994. État des stocks de homard des côtes du Québec et analyse des problématiques régionales. MPO, Pêches de l'Atlantique, Document de recherche, 94/7, 68 p .

Lobster landings in the Québec region have increased regularly during the last 20 years, reaching 3835 t in 1992. In 1993, landings decreased by 7 % from 1992, reaching 3552 t. In the Magdalen Islands, landings and abundance indices from at-sea- sampling and index-fishermen have all decreased relatively to 1992. Despite this decrease, the abundance level is still high, considering values for the last fifty years. Recruitment indices obtained from at-sea-sampling, i.e. prerecruit (67-75 mm CTL) CPUE were lower in 1993 compared to 1992, indicating the possibility of a decrease in landings for 1994. In the Gaspé, in 1993, landings showed a 10 % decrease from 1992. Abundance indices obtained from the index-fishermen program also decreased. CPUE from commercial at sea sampling showed a slight increase compared to 1992, in the middle and end of the fishing season. CPUE observed at the beginning of the season in 1992 and 1993 were lower compared to the average of the past 8 years. Colder springs in the last two years may have reduced catchability at the beginning of the season. The relationship between the abundance of prerecruits a given year and the landings the next year for the Gaspé is not as clear as what was observed in Magdalen Islands. Forecasting the trend of the landings for the next season is not possible. The recent increase in landings is generally attributed to an increase in the abundance of lobsters on the fishing grounds. Because the phenomenon was observed over the whole range of distribution of the species, it is believed that common environmental factors have favoured large-scale lobster recruitment. It is also believed that the increase in landings can be, to a certain extent, the result of an increase in some components of the fishing effort, which contributed namely to the exploitation of new grounds. Lobster populations are heavily exploited and landings a given year strongly depend on recruitment in that year. This dependance appears to be greater in the Gaspé. Research efforts are presently directed at forecasting the recruitment to the fishery one to four years in advance.

GENDRON, L., J.-P. DALLAIRE, 1992. Effet de l'augmentation de la taille des casiers sur l'effort de pêche et le taux d'exploitation des stocks de homard Homarus americanus sur les côtes du Québec. CSCPCA doc. rech., 92/117, 22 p .

GENDRON, L., 1992. Determination of the size at sexual maturity of the waved whelk, Buccinum undatum Linnaeus, 1758, in the Gulf of St. Lawrence, as a basis for the establishment of a minimum catchable size. J. Shellfish Res., 11: 1-7 .

GENDRON, L., 1992. Détermination d'une taille minimale de capture pour le crabe commun Cancer irroratus dans la baie des Chaleurs, Québec, à partir d'une analyse de rendement par recrue : analyse préliminaire. CSCPCA doc. rech., 92/43, 17 p .

ENNIS, J., K. DRINKWATER, P. OUELLET, P. BRUNEL, M. FRÉCHETTE, D. GAUTHIER, L. GENDRON, J. HIMMELMAN, C. HUDON, I. McQUINN, L. SAVARD, J. WORMS, 1991. Report of the Workshop on Invertebrates. Pages 47-54 in J.-C. Therriault (ed.). The Gulf of St. Lawrence : small ocean or big estuary ? Dept. of Fisheries and Oceans (Can. Spec. Publ. Fish. Aquat. Sci., 113) .

ENNIS, J., K. DRINKWATER, P. OUELLET, P. BRUNEL, M. FRÉCHETTE, D. GAUTHIER, L. GENDRON, J. HIMMELMAN, C. HUDON, I. McQUINN, L. SAVARD, J. WORMS, 1991. Rapport de l'atelier de travail sur les invertébrés. Pages 47-54 in J.-C. Therriault (éd.). Le golfe du Saint-Laurent : petit océan ou grand estuaire? Ministère des pêches et des océans (Publ. spéc. can. sci. halieut. aquat., 113) .

GENDRON, L., S. HÉBERT, 1991. Rendement et sélectivité de sept différents types de casiers utilisés pour la pêche au crabe commun Cancer irroratus et caractérisation des prises incidentes de homards Homarus americanus. Rapp. tech. can. sci. halieut. aquat., 1773, 22 p .

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A study of the yield and selectivity of 7 different types of traps used for fishing common crab, Cancer irroratus, was undertaken in Baie des Chaleurs, Quebec, in June and in August 1989. The highest crab yields were obtained with conical traps, independently of the type of entry to the trap, of the presence of escape vents or of the slope of the trap. The number of commercial size crabs (males greater than or approximate 89 mm carapace width) caught with these traps varied between 20-27 crabs/trap/day. Standard and modified lobster traps caught on the average 6-11 crabs/trap/day. The modified lobster trap did not catch lobster, despite the presence of this species on the fishing grounds, as shown by its occurrence in the standard lobster traps (4,8 lobsters/trap/day). On sandy bottoms, conical traps with escape vents, and with a conical aperture on the top, caught about 20 times fewer lobsters than the standard lobster traps. Conical traps to which a narrow rectangular entrance was added (2 different types) maximized crab catches while minimizing lobster catches. Manipulation of these traps is however more difficult. For practical reasons, we recommend the use of a conical trap with a conical aperture placed on top of the trap, although a certain amount of lobsters might be caught. The number of lobsters caught in the trap can howerver be minimized by placing a sufficient number of escape vents of appropriate dimensions.

GENDRON, L., 1991. Gestion de l'exploitation du buccin Buccinum undatum au Québec : détermination d'une taille minimale de capture. Rapp. tech. can. sci. halieut. aquat., 1833, 40 p .

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In order to establish a minimum catchable size for the whelk Buccinum undatum fishery in Quebec, work was undertaken to (1) determine the size and age at sexual maturity and (2) examine the selectivity and yield of whelk traps with different mesh sizes (1/24", 1/2", 1", 2" and 3"), to recommend the use of a mesh size reducing catches of immature whelks. The establishment of a minimum catchable size of 75 mm (3") (shell height) for the northern part of the Gulf, and of 65 mm (2 1/2") for Magdalen Islands is recommended in order to protect the brood stock. The enforcement of such a management tactic will necessitate the participation of fishermen who will have to discard undersized whelks at sea. No mesh size, among those tested, appear to simultaneously reduce the catch of small whelks and optimize the catch of large whelks. The establishment of a minimum catchable size will have serious consequences on fishing activities. In certain areas, application of this tactic will lead to the discard of a high proportion of the catch.

GENDRON, L., 1989. Seasonal growth of kelp Laminaria longicruris in Baie des Chaleurs, Québec, in relation to nutrient and light availability. Bot. Mar., 32: 345-354 .

McQUINN, I.H., L. GENDRON, J.H. HIMMELMAN, 1988. Area of attraction and effective area fished by a whelk (Buccinum undatum) trap under variable conditions. Can. J. Fish. Aquat. Sci., 45: 2054-2060 .

GENDRON, L., P. BERGERON, L. GOSSELIN, 1988. Détermination d'un niveau de récolte admissible de l'algue brune Ascophyllum nodosum sur la rive sud de l'estuaire du Saint-Laurent (Anse-au-Persil, Saint-Fabien-sur-Mer et Métis). CSCPCA doc. rech., 88/15, 23 p .

GENDRON, L., 1988. Exploitation et état du stock de mactres (Spisula solidissima) des Îles-de-la-Madeleine en 1986. Rapp. manus. can. sci. halieut. aquat., 1993, 17 p .

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GENDRON, L., 1987. Détermination d'un niveau de récolte admissible de laminaires Laminaria longicruris dans la Baie des Chaleurs, Québec. CSCPCA doc. rech., 87/8, 22 p .