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Bibliography of the Maurice Lamontagne Institute

Fishes / Sebastes spp. / Redfishes, Acadian redfish, Beaked redfish, Berghilt, Bream, Deepwater redfish, Golden redfish, Norway haddock, Norwegian redfish, Ocean perch, Redbarsch, Red bream, Redperch, Red sea perch, Rosefish, Sea bream, Sharp-beaked redfish, Soldier

GRÉGOIRE, F., W. BARRY, J. BARRY, C. LÉVESQUE, J.-L. BEAULIEU, M.-H. GENDRON, 2011. West coast of Newfoundland Capelin (Mallotus villosus M.) and Atlantic Herring (Clupea harengus harengus L.) larval survey, part 6 : abundance estimates and marine community analyses of the data collected in partnership with the industry (Barry Group) in July 2007. Can. Tech. Rep. Fish. Aquat. Sci., 2953, 65 p.

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In partnership with the Barry Group in Corner Brook, a larval survey was conducted on the west coast of Newfoundland in July 2007 to measure the abundance and to describe the spatial distribution of eggs and larvae of fish species sampled, two of which were commercially significant, capelin (Mallosus villosus) and Atlantic herring (Clupea harengus harengus). The most abundant eggs were from the CYT (cunner [Tautogolabrus adspersus] and yellowtail flounder [Limanda ferruginea]), CHW (cod [Gadus morhua], haddock [Melanogrammus aeglefinus], and witch flounder [Glyptocephalus cynoglossus]), and H4B (hake [Urophycis spp.], fourbeard rockling [Enchelyopus cimbrius], and American butterfish [Peprilus triacanthus]) groups. Among the larvae collected, the most abundant species were cunner, flounder (Pleuronectidae), and Atlantic mackerel (Scomber scombrus) followed by capelin, fourbeard rockling, radiated shanny (Ulvaria subbifurcata), cod, and Atlantic herring. Compared to the survey conducted in 2005, and omitting St. George’s Bay, the 2007 survey was characterized by a smaller number of Atlantic mackerel and capelin eggs and larvae. Egg groups CYT, CHW, and H4B, were also less abundant. The only increases in abundance were measured for windowpane (Scophthalmus aquosus) eggs, as well as radiated shanny, redfish (Sebastes spp.), sand lance (Ammodytes spp.), and snailfish (Liparis spp.) larvae. Generalized additive models (GAM) have shown that the abundance of eggs and larvae of most species sampled could be described using a smoothing function based on the interaction between the longitude and latitude of the stations. The abundance of Atlantic mackerel eggs and cod larvae have also been described by a second function based on water temperature. Finally, a last function based on the abundance of Atlantic mackerel eggs helped describe the abundance of larvae of this species. From abundance measurements of all sampled larvae, cluster and ordination analyses revealed the presence of a well-defined spatial structure within the larval community. This was mainly characterized by cunner and Flounder.

BOURDAGES, H., ARCHAMBAULT, D., BERNIER, B., FRECHET, A. GAUTHIER, J. GREGOIRE, F, LAMBERT, J, L. SAVARD, 2010. Résultats préliminaires du relevé multidisciplinaire de poissons de fond et de crevette d’août 2010 dans l’estuaire et le nord du golfe du Saint-Laurent ; Preliminary results from the groundfish and shrimp multidisciplinary survey in August 2010 in the Estuary and northern Gulf of St. Lawrence. MPO, Secrétariat canadien de consultation scientifique, Série des comptes rendus ; DFO, Canadian Science Advisory Secretariat, Proceedings Series, 2010/107, 98 p.

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In 2010, the annual summer survey for the assessment of abundance and distribution of groundfish and shrimp in the Estuary and the northern Gulf of St. Lawrence was conducted from August 2nd to September 1st onboard the CCGS Teleost. One of the primary objectives was to estimate abundance indices for the main groundfish species (particularly cod, Greenland halibut, Atlantic halibut and redfishes - fasciatus and mentella-), and for the Northern shrimp, and to identify the spatial distribution and biological characteristics of these species. Other objectives included monitoring the biodiversity of Estuary and the northern Gulf and describing oceanographic conditions observed in August. This report describes preliminary results on the catch rates and distribution of 18 taxa, as well as their size frequency distribution. These results were compared with results from the historical survey series that began in 1990, taking into account the equivalency factors used to convert the data from the tandem CCGS Alfred Needler-URI to the tandem CCGS Teleost-Campelen. In 2010, the abundance and biomass indices of many species were stable or decreased compared to 2009. In fact, the two redfish species (Sebastes fasciatus and S. mentella), cod, black dogfish, white hake and longfin hake show index values below the historical series means. Even if the Northern shrimp and snow crab indices presented a small decrease, they were in the range of the historical series means. Six species (Atlantic Halibut, Greenland Halibut, hagfish, American Plaice, witch, thorny skate) showed an increase for their indices in 2010. Except for Greenland Halibut, the indices for these species were among the highest values of their respective historical series. Besides the fact that no fishing activities took place along the southwestern part of Newfoundland due to mechanical problems, the geographic distributions of catches recorded for the different species in 2010 showed the same pattern as in previous years.

BUI, A.O.V., P. OUELLET, M. CASTONGUAY, J.-C. BRÊTHES, 2010. Ichthyoplankton community structure in the northwest Gulf of St. Lawrence (Canada) : past and present. Mar. Ecol. Prog. Ser., 412: 189-205.

Biodiversity can play an important role in the stability and resilience of ecosystems when these are faced with environmental change or anthropogenic impacts. Historically, the northwest Gulf of St. Lawrence had high fish egg and larval productivity. To assess changes in the ichthyoplankton community of this region, data from sampling surveys that were carried out in spring from 1985 to 1987 were compared with data from spring 2005 to 2007. Significant differences in ichthyoplankton abundances between the 2 decades and sampling times (May versus June) were revealed by multivariate analyses (nMDS, ANOSIM, PERMANOVA, and SIMPER) and univariate (ANOVA) analyses. Total ichthyoplankton abundance was lower in the 2000s than during the mid- 1980s. Although larval sandlance Ammodytes spp. abundances did not change significantly, other taxa, such as Stichaeidae larvae and H4B eggs (gadids and merlucciid hakes, rocklings, butterfish Peprilus triancanthus, windowpane Scophthalmus aquosus and Gulf Stream flounder Citharichthys arctifrons), became more abundant; the abundance of CHW eggs (cod Gadus morhua, haddock Melanogrammus aeglefinus, witch flounder Glyptocephalus cynoglossus), and redfish Sebastes spp. larvae generally declined by more than an order of magnitude. Greenland halibut Reinhardtius hippoglossoides larvae also appeared in the 2000s assemblages. This dominance shift in the ichthyoplankton community reflects the demise of large fish predators and the response of the non-commercial species. Our study provides much-needed new information concerning current biodiversity and productivity of the fish community in the Gulf of St. Lawrence and insights into changes influenced by groundfish collapse and environmental fluctuations.©2010 Inter-Research

GASCON, D., SONIA DUBÉ, 2010. Compte rendu du processus de consultation scientifique zonal sur le sébaste des unités 1 et 2, 25 et 26 février 2010, Institut Maurice-Lamontagne ; Proceedings of the zonal advisory process for Redfish in Units 1 & 2, February 25th and 26th, 2010, Maurice Lamontagne Institute. DFO, Canadian Science Advisory Secretariat, Proceedings Series ; MPO, Secrétariat canadien de consultation scientifique, Série des compte rendus 2010/018, 28 p.

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GOSSELIN, S., F. GRÉGOIRE, 2010. Évaluation de la pêche sportive hivernale dans le fjord du Saguenay en 2004, 14 décembre 2004, Institut Maurice-Lamontagne ; Assessment of ice sportfishing season in the Saguenay River in 2004, December 14, 2004, Maurice Lamontagne Institute. MPO, Secrétariat canadien de consultation scientifique, Série des comptes rendus ; DFO, Canadian Science Advisory Secretariat, Proceedings Series, 2009/048, 19 p.

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RABALAIS, N.N., R.J. DIAZ, L.A. LEVIN, R.E. TURNER, D. GILBERT, J. ZHANG, 2010. Dynamics and distribution of natural and human-caused hyposia. Biogeosciences, 7(2): 585-619.

Water masses can become undersaturated with oxygen when natural processes alone or in combination with anthropogenic processes produce enough organic carbon that is aerobically decomposed faster than the rate of oxygen re-aeration. The dominant natural processes usually involved are photosynthetic carbon production and microbial respiration. The re-supply rate is indirectly related to its isolation from the surface layer. Hypoxic water masses (<2 mg L-1, or approximately 30 % saturation) can form, therefore, under "natural" conditions, and are more likely to occur in marine systems when the water residence time is extended, water exchange and ventilation are minimal, stratification occurs, and where carbon production and export to the bottom layer are relatively high. Hypoxia has occurred through geological time and naturally occurs in oxygen minimum zones, deep basins, eastern boundary upwelling systems, and fjords. Hypoxia development and continuation in many areas of the world's coastal ocean is accelerated by human activities, especially where nutrient loading increased in the Anthropocene. This higher loading set in motion a cascading set of events related to eutrophication. The formation of hypoxic areas has been exacerbated by any combination of interactions that increase primary production and accumulation of organic carbon leading to increased respiratory demand for oxygen below a seasonal or permanent pycnocline. Nutrient loading is likely to increase further as population growth and resource intensification rises, especially with increased dependency on crops using fertilizers, burning of fossil fuels, urbanization, and waste water generation. It is likely that the occurrence and persistence of hypoxia will be even more widespread and have more impacts than presently observed. Global climate change will further complicate the causative factors in both natural and human-caused hypoxia. The likelihood of strengthened stratification alone, from increased surface water temperature as the global climate warms, is sufficient to worsen hypoxia where it currently exists and facilitate its formation in additional waters. Increased precipitation that increases freshwater discharge and flux of nutrients will result in increased primary production in the receiving waters up to a point. The interplay of increased nutrients and stratification where they occur will aggravate and accelerate hypoxia. Changes in wind fields may expand oxygen minimum zones onto more continental shelf areas. On the other hand, not all regions will experience increased precipitation, some oceanic water temperatures may decrease as currents shift, and frequency and severity of tropical storms may increase and temporarily disrupt hypoxia more often. The consequences of global warming and climate change are effectively uncontrollable at least in the near term. On the other hand, the consequences of eutrophication-induced hypoxia can be reversed if long-term, broad-scale, and persistent efforts to reduce substantial nutrient loads are developed and implemented. In the face of globally expanding hypoxia, there is a need for water and resource managers to act now to reduce nutrient loads to maintain, at least, the current status.©2010 European Geosciences Union

BOURDAGES, H., D. ARCHAMBAULT, D. BERNIER, A. FRECHET, J. GAUTHIER, F. GREGOIRE, J. LAMBERT, L. SAVARD, 2010. Résultats préliminaires du relevé multidisciplinaire de poissons de fond et de crevette d'août 2009 dans le nord du golfe du Saint-Laurent ; Preliminary results from the groundfish and shrimp multidisciplinary survey in August 2009 in the northern Gulf of St. Lawrence. Rapp. stat. can. sci. halieut. aquat. ; Can. Data Rep. Fish. Aquat. Sci., 1226, 84 p..

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In 2009, the annual summer survey for the assessment of abundance and distribution of groundfish and shrimp in the northern Gulf of St. Lawrence was conducted from July 31 to August 31 onboard the CCGS Teleost. One of the primary objectives was to estimate abundance indices for the mam groundfish species (particularly cod, Greenland halibut and redfish), and for the Northern shrimp, and to identify the spatial distribution and biological characteristics of these species. Other objectives included monitoring the biodiversity of the nOlthern Gulf and describing oceanographic conditions obser.ved in August. This report describes preliminary results on the catch rate and distribution of 15 taxa, as well as their size frequency distribution. These results were compared with results from the historical survey series that began in 1990, taking into account the equivalency factors used to convert the data from the tandem CCGS Alfred Needler-URI with the tandem CCGS Teleost-Campelen. In 2009, the abundance and biomass indices of many species have decreased compared to the previous years. In fact, the redfish, black dogfish and longfin hake indices are among the lowest values of the series. Greenland halibut, for which indices decreased by about 30 %, shows values similar to the early 2000's. However, the indices observed in 2009 for the other species (cod, Northern shrimp, Atlantic halibut, thorny skate, white hake, American plaice, witch flounder and snow crab) are comparable to the means of the last five years even though a decrease was observed compared to last year. The geographic distributions of catches recorded for the different species in 2009 show the same pattern as we have seen over the previous seven years

BUNDY, A., J.J. HEYMANS, L. MORISSETTE, C. SAVENKOFF, 2009. Seals, cod and forage fish: A comparative exploration of variations in the theme of stock collapse and ecosystem change in four Northwest Atlantic ecosystems. Prog. Oceanogr., 81(1-4): 188-206.

The facts: four Northwest Atlantic ecosystems, three cod stock collapses 15 years ago (plus one severely depleted), seals now top predator in all ecosystems, all had cod as a top predator before collapse, groundfish declines in all areas, forage base increased in most systems. No recovery in any system. Have these ecosystems fundamentally changed? Why? The challenge: compare and contrast these four ecosystems. The answer: using mass balance models, empirical data and a suite of ecosystem indicators, we explore how and why these systems have changed over time. At the ecosystem and community level, we see broad similarities between ecosystems. However, structurally and functionally these systems have shifted to an alternate state, with changes in predator structure, trophic structure and flow.Crown Copyright.©2009 Published by Elsevier Ltd.

SIROIS, P., G. DIAB, A.-L. FORTIN, S. PLOURDE, J.A. GAGNÉ, N. MÉNARD, 2009. Recrutement des poissons dans le fjord du Saguenay;Fish recruitment in the Saguenay Fjord. Rev. Sci. Eau;J. Water Sci., 22(2): 341-352.

In the Saguenay Fjord, the fish community is composed of more than 60 marine, diadromous and freshwater species, including many species exploited by the winter sport fishery such as the rainbow smelt (Osmerus mordax), redfish (Sebastes spp.), Atlantic cod (Cadus morhua), Greenland cod (Cadus ogac), and Greenland halibut (Reinhardtius hippoglossoides). We do not know if the recruitment of the fish species exploited by the winter sport fishery depends on the local production of recruits in the Saguenay Fjord or on exchanges with the St. Lawrence Estuary populations. Hence, we measured the spado-temporal distribution ofichthyoplankton in the Fjord to identify zones of larval production, retention or advection, in order to investigate the recruitment mechanisms of these stocks. We sampled ichthyoplankton at 21 stations on six occasions, from May to October 2004, and on five occasions, from June to September 2005. Results indicated that the recruitment of capelin (Mallotus villosus) and of the anadromous rainbow smelt (Osmerus mordax) relied on the local production and retention oflarvae within the Fjord. However, the recruitment of redfish (Sebastes spp.) and cods (Cadus spp.) depended on the immigration of juveniles from the St. Lawrence Estuary. Our results are corroborated by a review of previous studies of these fish populations. Studying the recruitment mechanisms of fish populations in the Saguenay Fjord supports a sustainable exploitation of these locally important fisheries resources, in accordance with the mission of Fisheries and Oceans Canada and consistent with the conservation program of the Saguenay St. Lawrence Marine Park.©2009 RSE inc.

SÉVIGNY, J.-M., A. VALENTIN, A. TALBOT, N. MÉNARD, 2009. Connectivité entre les populations du fjord du Saguenay et celles du golfe du Saint-Laurent;Connectivity between Saguenay Fjord populations and those of the Gulf of St. Lawrence. Rev. Sci. Eau;J. Water Sci., 22(2): 315-339.

Microsatellite and allozyme analyses on various species of bottom fishes (cod, Greenland halibut and redfish) and crustace ans (snow crab, northern shrimp) show that individuals from the Saguenay Fjord and from the St. Lawrence belong ta the same populations. The only genetic difference observed is at the Pan I locus of cod. This differentiation may be caused by selection that would act in the Saguenay Fjord, rather than due to the genetic isolation of the population. Complementary data available for bottom fish (elemental composition of otoliths, body morphometry, and para ice fauna) show clear differences between the aguenay and the St. Lawrence. These differences suggest residence of individuals in the Saguenay and the St. Lawrence for a large proportion of their life cycle. Considering the low larval survival observed in the fjord, this review Suggests that the bottom fish populations from the Saguenay represent sink populations whose recruitment depends largely or solely on migration of juvenile from the St. Lawrence. Although there are no complememary data for crustacean species, it is possible that migration and residence are processes operating for those species as well.©2009 RSE inc.

BOURDAGES, H., D. ARCHAMBAULT, B. BERNIER, A. FRÉCHET, J. GAUTHIER, F. GRÉGOIRE, J. LAMBERT, L. SAVARD, 2008. Résultats préliminaires du relevé multidisciplinaire de poissons de fond et de crevette d’août 2007 dans le nord du golfe du Saint-Laurent ; Preliminary results from the groundfish and shrimp multidisciplinary survey from August 2007 in the northern Gulf of St. Lawrence. MPO, Secrétariat canadien de consultation scientifique, Document de recherche ; DFO, Canadian Science Advisory Secretariat, Research Document, 2008/046, 77 p.

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In 2007, the annual summer survey for the assessment of abundance and distribution of groundfish and shrimp in the Quebec region was conducted from August 3rd to September 1st in the estuary and northern Gulf of St. Lawrence on board the CCGS Teleost. One of its primary objectives was to estimate abundance indices for the main groundfish species, including the three species targeted by the survey (cod, Greenland halibut, redfish) and Northern shrimp (also targeted by the survey), identify spatial distribution and their biological characteristics. Among the other objectives, the survey aimed at providing a concurrent portrait of environmental conditions in the Gulf for 7 of the Gulf’s 8 geographic regions considered in the assessment of the Gulf’s physical conditions. This report describes for 14 species the preliminary results for catch rate and distribution, as well as their size frequency distribution. These results were compared with the results from the historical survey series introduced in 1990, taking into account the equivalency factors used to convert the data from the tandem CCGS Alfred Needler-URI with the tandem CCGS Teleost-Campelen. None of the species showed much variation compared with the two previous years, except for Atlantic halibut with a still increasing abundance index in 2007. The geographic distribution of catches recorded for the different species in 2007 can be compared to the five previous years. In 2007, the temperatures recorded for surface waters and for the cold intermediate layer (CIL) were generally colder for the entire covered area compared with the temperatures recorded in 2006. The layers <1°C and <0°C of the CIL were much thicker in 2007 than in 2006. However, the temperatures recorded for deep water (300+m) were similar during these two years. Concentrations of dissolved oxygen in the Estuary waters were still considered hypoxic in 2007.

BOURDAGES, H., D. ARCHAMBAULT, B. BERNIER, A. FRÉCHET, J. GAUTHIER, F. GRÉGOIRE, J. LAMBERT, L. SAVARD, 2008. Résultats préliminaires du relevé multidisciplinaire de poissons de fond et de crevette d'août 2008 dans le nord du golfe du Saint-Laurent ; Preliminary results from the groundfish and shrimp multidisciplinary survey from August 2007 in the northern Gulf of St. Lawrence. Rapp. stat. can. sci. halieut. aquat. ; Can. Data Rep. Fish. Aquat. Sci., 1210, 84 p..

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In 2008, the annual summer survey for the assessment of abundance and distribution of groundfish and shrimp in the northern Gulf of St. Lawrence was conducted from July 24th to August 25th onboard the CCGS Teleost. One of the primary objectives was to estimate abundance indices for the principal groundfish species, including the three fish species targeted by the survey (cod, Greenland halibut and redfish), and for the Northern shrimp, identify for each of them their spatial distribution and biological characteristics. One of the other objectives, the survey aimed at providing a concurrent portrait of environmental conditions observed in August in the Gulf. This report describes for 14 species the preliminary results for their catch rate and distribution, as well as their size frequency distribution. These results were compared with results from the historical survey series that began in 1990, taking into account the equivalency factors used to convert the data from the tandem CCGS Alfred Needler-URI with the tandem CCGS Teleost-Campelen. While the biomass index in 2008 is still increasing for Atlantic halibut, the indices obtained for the other species are comparable to the means of the last three years. The geographic distributions of catches recorded for the different species in 2008 show the same pattern as for the five previous years.

CAMPANA, S. E., A. VALENTIN, J.-M. SÉVIGNY, D. POWER, 2007. Tracking seasonal migrations of redfish (Sebastes spp.) in and around the Gulf of St. Lawrence using otolith elemental fingerprints. Can. J. Fish. Aquat. Sci., 64: 6-18.

Large concentrations of beaked redfish (Sebastes mentella and Sebastes fasciatus) overwinter in the Cabot Strait and the approaches of the Gulf of St. Lawrence each year. Synoptic research vessel surveys indicate that redfish are distributed more widely in the summer than in the winter, particularly within the Gulf. Significant differences in the trace element composition of the otolith ("otolith elemental fingerprint") were observed among summer aggregations, indicating that the aggregations maintained some degree of separation while in the Gulf. Sebastes mentella and S. fasciatus were readily distinguished based on otolith elemental fingerprints. Using the elemental fingerprints of the summer samples as a natural tag, we found that S. mentella tended to move out of the Gulf in the winter. Aggregations of S. mentella found in the east during the summer were not found in our winter collections. The elemental fingerprints of S. mentella from the Saguenay Fjord were clearly distinct from redfish further east in the Gulf of St. Lawrence, indicating that this group had been separated from other redfish for much of their life. The implications of our findings extend not only to the fisheries management of redfish, but also to the extent of movement expected of deepwater fish species.

CYR, C., D. BERNIER, M. CASTONGUAY, 2006. Compte rendu de l'atelier zonal sur les nouveaux éléments probants concernant la question de la distinction des stocks de sébaste des Unités 1 et 2 dans le contexte du mode de gestion actuelle, 9 février 2006, Institut Maurice-Lamontagne, Mont-Joli, Qc ; Proceedings of the Zonal Workshop on new evidence regarding the issue of redfish stock discrimination between Units 1 and 2 in the context of the current management practice, 9 February 2006, Maurice Lamontagne Institute, Mont-Joli, Qc. MPO, Secrétariat canadien de consultation scientifique, Série des comptes rendus ; DFO, Canadian Science Advisory Secretariat, Proceedings Series, 2006/019, 13 p.

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A zonal workshop of one-day was held in order to examine new elements concerning the distinction of redfish stocks in Units 1 and 2 within the context of the current management approach. During the meeting held on February 9th, 2006, participants studied the most recent data concerning population structure of Northwest Atlantic redfish stocks. Specifically, genetic and geometric morphometric data as well as data on the elemental composition of otoliths were examined. The discussions that were held during the workshop were not entirely conclusive as to the biological relevance of the management units currently used for redfish. Nevertheless, it was agreed to that this point be added to the agenda of a future workshop, which should be held within a few months.

SAVENKOFF, C., B. MORIN, D. CHABOT, M. CASTONGUAY, 2006. Main prey and predators of redfish (Sebastes spp.) in the northern Gulf of St. Lawrence during the mid-1980s,mid-1990s, and early 2000s. Can. Tech. Rep. Fish. Aquat. Sci., 2648, 23 p.

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We used results of mass-balance models to describe the changes in the structure and functioning of the northern Gulf of St. Lawrence ecosystem related to redfish (Sebastes spp.) for the mid-1980s, the mid-1990s, and the early 2000s. The net decrease in biomass of the demersal species in the early 1990s and the ensuing drop in predation led to an ecosystem structure dominated by small-bodied pelagic species and marine mammals. Redfish consumption largely decreased from the mid-1980s to the early 2000s. Large zooplankton, capelin (Mallotus villosus), and small zooplankton were the main prey consumed by redfish for each time period. There was a net decrease in total mortality and predation on redfish from the mid-1980s to early 2000s. Fishing mortality also decreased over the same time period as the redfish fishery in the Gulf has been under moratorium since 1995. Predation was the main cause of redfish mortality for each time period. The main predators of redfish were large cod (Gadus morhua) during the mid-1980s and harp seals (Pagophilus groenlandicus) and skates during the mid-1990s and early 2000s. Even though the proportion of redfish in the diet composition of each of these three predators was generally low, their predation could account for high percentages of total mortality on redfish. Cannibalism also appeared to be an important source of redfish mortality (between 10 and 15 % of total mortality)

SAVENKOFF, C., L. SAVARD, B. MORIN, D. CHABOT, 2006. Main prey and predators of northern shrimp (Pandalus borealis) in the northern Gulf of St. Lawrence during the mid-1980s, mid-1990s, and early 2000s. Can. Tech. Rep. Fish. Aquat. Sci., 2639, 28 p.

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We used results of mass-balance models to describe the changes in the structure and functioning of the northern Gulf of St. Lawrence ecosystem related to northern shrimp (Pandalus borealis) for the mid-1980s, the mid-1990s, and the early 2000s. The net decrease in biomass of the large-bodied demersal species and the ensuing drop in predation in the mid-1990s may explain the increase in abundance of the northern shrimp at the end of the 1990s. Shrimp was among the main prey species, and predation was the main cause of shrimp mortality for all time periods. Greenland halibut (Reinhardtius hippoglossoides) progressively replaced cod (Gadus morhua) and redfish (Sebastes spp.) as the main shrimp predators. Since the biomass of Greenland halibut sharply increased since 1995, its effect via predation as well as fishing pressure should be considered in the elaboration of management strategies for shrimp in the northern Gulf of St. Lawrence.

GRÉGOIRE, F., 2004. Capelin of the Estuary and Gulf of St. Lawrence (4RST) in 2003. Science, Stock Status Report, 2004/001, 14 p.

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GRÉGOIRE, F., 2004. Capelan de l'estuaire et du golfe du Saint-Laurent (4RST) en 2003. Rapport sur l'état des stocks, 2004/001, 14 p.

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SAVENKOFF, C., M. CASTONGUAY, A.F. VÉZINA, S.-P. DESPATIE, D. CHABOT, L. MORISSETTE, M.O. HAMMILL, 2004. Inverse modelling of trophic flows through an entire ecosystem: the northern Gulf of St. Lawrence in the mid-1980s. Can. J. Fish. Aquat. Sci., 61: 2194-2214.

Mass-balance models using inverse methodology have been constructed for the northern Gulf of St. Lawrence ecosystem in the mid-1980s, before the groundfish collapse. The results highlight the effects of the major mortality sources (fishing, predation, and other sources of mortality) on the fish and invertebrate communities. Main predators of fish were large cod (Gadus morhua followed by redfish (Sebastesspp.), capelin (Mallotus villosus), and fisheries. Large cod were the most important predator of small cod, with cannibalism accounting for at least 44 % of the mortality of small cod. The main predators of large cod were harp (Phoca groenlandica) and grey (Halichoerus grypus) seals. However, predation represented only 2 % of total mortality on large cod. Mortality other than predation dominated the mortality processes at 52 % of the total, while the fishery represented 46 %. Tests were performed to identify possible sources of this unexplained mortality. The only way to significantly reduce unexplained mortality on large cod in the model was to increase landings of large cod above those reported. This suggests that fishing mortality was substantially underestimated in the mid-1980s, just before the demise of a cod stock that historically was the second largest in the northwest Atlantic.©2004 NRC Canada

GASCON, D. (éd.), 2003. Redfish Multidisciplinary Research Zonal Program (1995-1998) : Final Report. Can. Tech. Rep. Fish. Aquat. Sci., 2462, 152 p.

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This report provides under the form of extended abstracts the main results of the Redfish Multidisciplinary Research Program (1995-1999) which sought to examine aspects of the biology and fisheries of redfish to develop a better understanding of these species in order to insure long term economic viability and sustainability of the fishery. The program was divided into four main components: 1) Species identification and stock structure; 2) Improved stock assessment and management approaches; 3) Distribution in relation to enbroad consultation with the redfish fishing industry and the results presented to them at a final workshop held in Novembre 1999.

GASCON, D. (éd.), 2003. Programme de recherche multidisciplinaire sur le sébaste (1995-1998) : rapport final. Rapp. tech. can. sci. halieut. aquat., 2462, 152 p.

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This report provides under the form of extended abstracts the main results of the Redfish Multidisciplinary Research Program (1995-1999)_which sought to examine aspects of the biology and fisheries of redfish to develop a better understanding of these species in order to insure long term economic viability and sustainability of the fishery. The program was divided into four main components: 1) Species identification and stock structure; 2) improved stock assessment and management approaches; 3) distirbution in relation to environmental conditions; and 4) recruitment studies. These objectives were established in a broad consultation with the redfish fishing industry and the results presented to them at a final workshop held in November 1999.

BOURDAGES, H., D. ARCHAMBAULT, B. MORIN, A. FRÉCHET, L. SAVARD, F. GRÉGOIRE, M. BÉRUBÉ, 2002. Résultats préliminaires du relevé multidisciplinaire de poissons de fond et de crevette d'août 2002 dans le nord du golfe du Saint-Laurent ;. MPO, Secrétariat canadien de consultation scientifique, Document de recherche ; DFO, Canadian Science Advisory Secretariat, Research Document, 2002/090, 69 p.

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In 2002, the groundfish and shrimp multidisciplinary survey in the northern Gulf took place between August 1st and September 1st. A total of 207 fishing tows were conducted over the entire area of which 190 were successful, which corresponds to 76 % of the initial objective of 250 tows. Summary results concerning biomass and abundance, length frequencies and distribution of catch rates are presented for 13 species, including the four that are targeted by the survey (cod, Greenland halibut, redfish and shrimp). Results from 2002 are compared with those from previous years in order to have an indication of the trends for the 13 years time series. However results from 2002 are preliminary and must be considered as such pending laboratory analysis and completion of the validation of data. According to these preliminary results, biomass indices for cod, redfish, witch flounder and American plaice are very low in the northern Gulf while those of shrimp and Greenland halibut have remained high. A general decline in catches is observed for the majority of species along the West Coast of Newfoundland. However, the coverage of this area in 2002 was restricted due to frequent gear damage.

LAMBERT, J.-D., S. BÉRUBÉ, 2002. La pêche sportive hivernale dans le fjord du Saguenay. Rapp. tech. can. sci. halieut. aquat., 2445, 58 p.

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Ice fishing on the Saguenay Fjord attracts more than 50,000 fishermen-days annually, leading to different interventions to assure resource conservation as well as its sustainable development. A biological program was initiated in 1995 from a partnership between associations of local fishers, the Societe touristique du fjord, the Societe d'electrolyte et de chimie Alcan Ltee., the Societe de la faune et des parcs du Quebec, the Societe des etablissements de plein air du Quebec and the Department of Heritage Canada (Parks Canada) comanager of the Saguenay-St. Lawrence Marine Park, and the Dept. of Fisheries and Oceans, responsible for the scientific study. The biological program consisted of two working parties that required the participation of 32 volunteers from the local population. The first team consisted of eight samplers who collected catch and effort data on 20 occasions throughout the fishing season. The second team was composed of 24 fishermen who registered the length-weight, and condition of captured fish.

BERNIER, B., B. MORIN, 2002. Description des relevés par grille de sébaste dans le golfe du Saint-Laurent de 1998 à 2000 ; Description of redfish grid surveys in the Gulf of St. Lawrence from 1998 to 2000. Rapp. can. ind. sci. halieut. aquat. ; Can. Ind. Rep. Fish. Aquat. Sci., 265, 39 p.

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Surveys, conducted by GEAC (Groundfish Enterprise Allocation Council) in collaboration with DFO, were carried out between 1998 and 2000 in the Gulf of St. Lawrence according to a definite sampling strategy. The main objectives of these grid surveys were to describe the distribution of redfish in the Gulf of St. Lawrence and at the mouth of the Gulf and to construct an abundance index. To fulfil these objectives, a systematic grid sampling plan was used. The distribution of the redfish catches for the three years showed the highest concentrations of redfish were found at the mouth of the Gulf, in NAFO Divisions 4T, 4Vn, and 4R. The summer GEAC grid survey catch rate index showed a decreasing trend between 1998 and 2000. The length frequency distributions for the redfish from the summer surveys (1998 to 2000) display two modes: between 13 and 19 cm, corresponding to the 1993-1005 year-classes, and between 28 and 37 cm, dominated by the 1980 year-class. The continuation of the GEAC early-summer surveys should provide information that will be useful for better describing the distribution pattern of redfish and to extend the series of this new abundance when redfish are more likely to be found in their summer geographic range in the Gulf. This index can be compared to the other abundance indices from surveys (DFO and Sentinel) conducted in the summer and fall.

ROQUES, S., J.-M. SEVIGNY, L. BERNATCHEZ, 2001. Evidence for broadscale introgressive hybridization between two redfish (genus Sebastes) in the North-west Atlantic : a rare marine example. Mol. Ecol., 10:149-165.

LAMBERT, J.-D., J. BERGERON, 2000. La pêche sportive hivernale dans le fjord du Saguenay. Naturaliste can., 124(2): 67-68.

LAROCQUE, R., 2000. A SCUBA technique for collecting live Sebastes spp. Specimens. Can. Tech. Rep. Fish. Aquat. Sci., 2309: 13 p.

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Redfish species (Sebastes sp.) are typically found in deep water and are highly vulnerable to decompression damage when brought to the surface. When limited numbers of live specimens are required for experimental work, collection by SCUBA divers in the relatively shallow waters of the St. Lawrence Estuary was shown to be an efficient method that reduced the potential for damage to the fish. Custom made diver-carried cages contributed to limiting the fish's stress. in situ decompression was the preferred method for preventing internal damage due to the increased volume of the gas-bladder. Fish densities had to be relatively high for the divers to achieve a reasonable level of success during the 20 to 30 minutes of available bottom time on each dive. Four series of dives were done over a 25 month period. A total of 249 fish were collected, averaging seven to eight fish per dive. Methods to reduce mortality due to decompression and transport are discussed.

ROQUES, S., D. PALLOTTA, J.-M. SÉVIGNY, L. BERNATCHEZ, 1999. Isolation and characterization of polymorphic microsatellite markers in the North Atlantic redfish (Teleostei : Scorpaenidae, genus Sebastes). Mol. Ecol., 8: 685-702.

RUNGE, J.A., Y. De LAFONTAINE, 1996. Characterization of the pelagic ecosystem in surface waters of the northern Gulf of St. Lawrence in early summer : the larval redfish - Calanus - microplankton interaction. Fish. Oceanogr., 5: 21-37.

GILBERT, M., 1996. Mortalités de sébastes dans la région de la Baie des Ha! Ha!, fjord du Saguenay : un choc thermique. Naturaliste can., 120(1): 61-64.

GILBERT, M., C.M. COUILLARD, 1995. Observations de mortalités de sébastes (Sebastes sp.) dans la région de la baie des Ha!Ha!, fjord du Saguenay : examen des causes possibles. Rapp. manus. can. sci. halieut. aquat., 2278, 15 p.

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In 1993 and 1994, redfish mortalities were reported on five occasions between July and October in the area of Baie des Ha! Ha!, in the Saguenay Fjord. The similar circumstances in which all these mortalities occurred indicate that they are related to a single cause. Low concentrations of heavy metals and organochlorines in tissues of individuals examined indicate that a long term bioaccumulation of contaminants is unlikely to have caused the observed mortalities. Mortalities resulting from epizootics, dismissed fisheries catches, or an acute intoxication caused by the presence of pollutants or toxic phytoplanktonic algae are all possible, although the observed events are not typical of such mortality causes. All mortalities were observed during the same phase of the tidal cycle, indicating a possible link with physicochemical and hydrodynamic conditions in the area of baie des Ha! Ha!. Redfish mortalities thus could have resulted from an anoxic, osmotic or thermal stress caused by increased local water mass movements during spring tides. Unusually cold summer conditions in the deep water mass of the baie des Ha! Ha! area, following particularly severe winters in 1993 and 1994, then would have induced the observed mortalities. However, additional information on the environmental conditions in which redfish mortalities occur, the characteristics and health status of affected individuals, as well as on the tolerance and acclimation limits of redfish to low temperature, is needed in order to determine with certainty their exact cause of mortality.

GASCON, D. (éd.), 1994. Rapport sur l'état des stocks de poissons pour la région du Québec en 1994 ; Fish stocks status report for the Quebec region in 1994. Rapp. manus. can. sci. halieut. aquat. ; Can. Manuscr. Rep. Fish. Aquat. Sci., 2253, 71 p.

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Fish stock assessments were reviewed regionally for the first time in 1994. This document describes in detail the technical basis for the assessment of fish stocks made at the Maurice Lamontagne Institute in May 1994. The stocks described are : herring on the west coast of Newfoundland (NAFO Division 4R), cod in the northern Gulf of St-Lawrence (NAFO Divisions 3Pn, 4R and 4S), mackerel in the northwest Atlantic (NAFO subareas 2 to 6), redfish in the Gulf of St-Lawrence - Unit 1 (NAFO Divisions 4R, 4S and 4T + 3Pn-4Vn[Jan.-May]), and Greenland halibut in the Gulf (NAFO Divisions 4R, 4S and 4T). Summaries of climatic conditions in the Gulf of St-Lawrence in 1993, and of the status of the main biological components are also included. This report provides the technical descriptions supporting the conclusions on stock status in 1994.

MORIN, B., D. POWER, P. GAGNON, 1994. Distribution of redfish (Sebastes spp.) in the Gulf of St. Lawrence and in the Laurentian Channel based on RV surveys and commercial fishery catch. MPO, Pêches de l'Atlantique, Document de recherche, 94/91, 52 p.

[Abstract only available in French]
L'analyse des relevés de poissons de fond dans les divisions 3Ps3Pn4RST de 1978 à 1993 a montré que le sébaste était concentré dans la région du détroit de Cabot en janvier et février. Cette observation semble s'être amplifiée depuis 1990 et les concentrations de sébaste débordent dans la sous-division 3Ps. La distribution des taux de capture de la pêche commerciale d'hiver supporte les données des relevés. En mai, les activités de pêche se déplacent vers le nord dans le golfe du Saint-Laurent, ainsi que vers le sud dans le chenal Laurentien, à la limite de 4Vn et 4Vs jusqu'au mois d'octobre. Les données de taux de capture analysées suggèrent que la migration du sébaste dans la région de Détroit de Cabot (4RT, 3Pn et 4Vn) a débuté aussi tôt que novembre au cours des trois dernières années ce qui ne concorde pas avec les unités de gestion présentement en place (i.e. 3Pn et 4Vn sont considérés comme du sébaste du chenal Laurentien ou Unité 2). La distribution du sébaste par groupe de longueur lors des relevés de poissons de fond a montré un déplacement vers le sud dans le détroit de Cabot à mesure que la taille des poissons augmente. La distribution et la migration des deux principales espèces de sébaste (Sebastes mentella and S. fasciatus) dans le golfe du Saint-Laurent semblent différentes et d'autres analyses sont requises afin de décrire l'impact sur la pêche.

MORIN, B., B. BERNIER, 1994. Le stock de sébaste (Sebastes spp.) du golfe du Saint-Laurent (4RST + 3Pn4Vn [jan.-mai] : état de la ressource en 1993. MPO, Pêches de l'Atlantique, Document de recherche, 94/24, 62 p.

[Abstract only available in French]
Les débarquements totaux préliminaires de sébaste du golfe du Saint-Laurent en 1993 ont atteint 51,000 t. Le TAC pour 1993 était de 60,000 t pour la nouvelle unité de gestion 1 (divisions 4RST + 3Pn et 4Vn (janvier-mai). Il a été réduit de façon préventive à 30,000 t en 1994. La pêche en 1993 a été dominée par les poissons nés vers 1980 et ceux nés au début des années 1970. Les poissons de ces deux groupes sont principalement de l'espèce Sebastes mentella. Les cohortes de 1985 et 1988 ont vu leur abondance diminuer rapidement depuis 1991 et ce sont des poissons identifiés comme S. fasciatus. Selon des relevés d'abondance, la biomasse du stock est en diminution et le taux d'exploitation est aux environs de 28 % ce qui est très élevé pour une espèce à croissance lente comme le sébaste et ce niveau est supérieur à F 0.1. La réduction du TAC à 30,000 t en 1994 va permettre de réduire le taux d'exploitation. Toutefois, ce niveau de capture n'est probablement pas soutenable à moyen terme, étant donné la biomasse présente (probablement en-dessous de 200,000 t) et l'absence de recrutement important.

GASCON, D. (éd.), 1994. Fish stocks status report for the Quebec region in 1994. Can. Manuscr. Rep. Fish. Aquat. Sci., 2253, 71 p.

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Fish stock assessments were reviewed regionally for the first time in 1994. This document describes in detail the technical basis for the assessment of fish stocks made at the Maurice Lamontagne Institute in May 1994. The stocks described are : herring on the west coast of Newfoundland (NAFO Division 4R), cod in the northern Gulf of St-Lawrence (NAFO Divisions 3Pn, 4R and 4S), mackerel in the northwest Atlantic (NAFO subareas 2 to 6), redfish in the Gulf of St-Lawrence - Unit 1 (NAFO Divisions 4R, 4S and 4T + 3Pn-4Vn[Jan.-May]), and Greenland halibut in the Gulf (NAFO Divisions 4R, 4S and 4T). Summaries of climatic conditions in the Gulf of St-Lawrence in 1993, and of the status of the main biological components are also included. This report provides the technical descriptions supporting the conclusions on stock status in 1994.

OUELLET, P., J.-P. ALLARD, J.-F. ST-PIERRE, 1994. Distribution des larves d'invertébrés décapodes (Pandalidae, Majidae) et des oeufs et larves de poissons dans le nord du golfe du Saint-Laurent en mai et juin de 1985 à 1987 et 1991-1992. Rapp. tech. can. sci. halieut. aquat., 2019, 60 p.

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From 1985 to 1987, and in 1991 and 1992, seven plankton surveys were conducted, between the end of April and early July in the northern gulf of S t. Lawrence. These missions provide informations on the species composition and the distribution of larvae of invertebrate decapods and of the eggs and larvae of fish species. A total of 28 species from 13 families (2 families of decapods and 11 fadies of fishes) were enumerated from these surveys. The larvae of the shrimp Pandalus spp. and crabs (Chionoecetes opilio andlor Hyas spp.) are the first to be found in large numbers in the northern Gulf. Moreover, the decapod larvae were always more abundant than the larval ichthyoplankton. The larvae of sandlances (Ammudytes spp.) and redfishes (Sebastes spp.) dominated the larval fish fauna. In May, in the northern Gulf, fish eggs were mostly represented by the eggs of the Atlantic cod (Gadus mrhua) and witch flounder (Glyptocephalus cynoglossus). The analysis of cod egg distribution from 1985 to 1987 revealed that there was simultaneous spawning events occuring in each sector, as soon as early-May, possibly from independent reproductive units of the northern Gulf cod population.

MORIN, B., B. BERNIER, 1993. Redfish (Sebastes spp.) stock of the Gulf of St. Lawrence (4RST + 3Pn4Vn [Jan.-May]) : state of the resource in 1992. DFO, Atlantic Fisheries, Research Document, 93/42, 56 p.

MORIN, B., B. BERNIER, 1993. Le stock de sébaste (Sebastes spp.) du golfe du Saint-Laurent (4RST+3Pn-4Vn [jan.-mai]) : état de la ressource en 1992. MPO, Document de recherche sur les pêches dans l'Atlantique, 93/42, 56 p.

Preliminary estimates put total 1992 landings of redfish from the Gulf of St. Lawrence at 77,384 t. Winter fishing (Jan.-April) has increased sharply in recent years and represented 47 % of landings in 1992. Catches continued to rise in 3Pn and 4Vn in 1992. Most landings were made by Shilikov-Turbo midwater trawls (71 %) and bottom trawls (27 %). The dominant commercial length frequency is the 29-31 cm mode, which corresponds to the 1981 year-class. A second mode, 35 to 37 cm, is made up of the year- classes from the early 1970s. The standardized catch rate series for bottom and midwater trawls combined and for bottom trawls only reveal three peaks, the last of which began in 1988. Catch rates increased 20 % in 1992. Summer research survey results show that biomass declined 20 % in 1992, while length frequency modes are similar to those of the commercial fishery. In addition, a juvenile fish mode at 14 cm (1988 year-class) is also evident. The 1981 year-class will constitute the main component of the fishery for the next three to four years, before the next recruitment. Until then, catch rates and biomass should decline, and if catches remain constant over this period, the exploitation rate should rise.

SÉVIGNY, J.-M., Y. De LAFONTAINE, 1992. Identification of redfish juveniles in the Gulf of St. Lawrence using genotypic specific variations. Pages 69-73 in Y. De Lafontaine, T. Lambert, G.R. Lilly, W.D. McKone & R.J. Miller (ed.). Juvenile stages : the missing link in fisheries research : report of a workshop. DFO (Can. Tech. Rep. Fish. Aquat. Sci., 1890).

MORIN, B., B. BERNIER, 1992. Évaluation du stock de sébaste (Sebastes spp.) du golfe du Saint-Laurent : 4RST + 3Pn4Vn (jan.-mai). CSCPCA doc. rech., 92/59, 45 p.

LABERGE, E., S. HURTUBISE, 1989. Évaluation du stock de sébaste (Sebastes spp.) des divisions 4RST de l'OPANO. CSCPCA doc. rech., 89/50, 47 p.

RUNGE, J.A., 1988. Should we expect a relationship between primary production and fisheries? The role of copepod dynamics as a filter of trophic variability. Hydrobiologia, 167/168: 61-71.

RUBEC, P.J., 1988. Changes in redfish distributions and abundance with reference to changes in bottom temperatures in the Gulf of St. Lawrence from 1983 to 1987. NAFO SCR Doc., 88/92, 24 p.

Marked changes in the distribution and abundance of redfish have occurred in the Gulf of St. Lawrence during the 1980’s. A reduction in the catch-per-unit-effort(CPUE)was noted with the standardized commercial CPUE, research vessel CPUE and with logbook data. Weight per two data from summer reseerch vessel surveys was analyzed by means of Duncans Range tests and with a four factor Analysis of Variance. The treatment factors were 5 Temperature Classes, 3 Areas, 4 Years, and Depth Classes. Temperature was found to be a highly significant factor in explaining redfish abundance. Weight per two was significantly higher at 6-8 °C from Duncan’s Range test. Temperature was the most significant factor in the ANOVA. There was also a weak significance for Depth Class. A second order interaction Depth Class* Years and Duncan’s tests by Depth Class indicate that redfish changed their depth distributions in response to a contraction and then an expansion of the warm bottom water layer. Area was not significant indicating that redfish exhibited little exchange between areas. A significant third order interaction TClass*DClass*Years appears to have resulted from changes in temperature between years. A cooling trend in 1984 caused the redfish to move into deeper water and may have caused a significant proportion of the biomass to become pelagic. A warming trend which peaked in 1986 allowed redfish to expand their distributions and helped increase their availability to bottom trawling.

LABERGE, E., 1988. Assessment of divisions 4RST redfish (Sebastes spp.). CAFSAC Res. Doc., 88/44, 44 p.

LABERGE, E., P.J. RUBEC, D. GASCON, D.B. ATKINSON, 1987. Assessment of 4RST redfish (Sebastes spp.). CAFSAC Res. Doc., 87/64, 45 p .

Reported landings for the NAFO Divisions 4RST redfish fishery in 1986 were estimated at 33,107 t. Although they constitute a 5,000 t increase from last year, they still represent only 60 % of the TAC. Catch rates for bottom trawls (excluding Engels high-lift), Engels high-lift trawls and midwater trawls were analyzed separately using a multiplicative model. The catch rate series shows 2 distinct peaks, one in 1967-1968 (1.33 t/h) and the other in 1981-1982 (1.29 t/h) and have declined since then; the decline appears to have stopped in 1986. Length frequency distributions based on commercial sampling and research survey data show the presence of 2 strong year-classes : one from the early 1970's (fish about 30 cm) and one from the early 1980's (fish about 20 cm). These smaller fish should be recruiting to the fishery in the next few years. The current biomass (beginning of 1987) was estimated from a non-linear version of the Schaefer general production model to be 473,000 t. Because of uncertainties with regard to the changes in availability of fish to the gear, and therefore the effort levels implied, the recommended catch for 1988 were set at the 2/3fmey equilibrium yield of 56,000 t.