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Bibliography of the Maurice Lamontagne Institute

Jean-Louis BEAULIEU

GRÉGOIRE, F., W. BARRY, J.-J. BARRY, J. BARRY, 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 8 : abundance estimates and marine community analyses of the data collected in partnership with the industry (Barry Group) in july 2008. Can. Tech. Rep. Fish. Aquat. Sci., 2954, 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 2008 to measure the abundance and to describe the spatial distribution of eggs and larvae of the main fish species encountered. In the survey, eggs were most abundant in the CYT group (Cunner [Tautogolabrus adspersus] and Yellowtail Flounder [Limanda ferruginea]), followed by Atlantic Mackerel (Scomber Scombrus) eggs and eggs from the CHW group (Cod [Gadus morhua], Haddock [Melanogrammus aeglefinus], and witch Flounder [Glyptocephalus cynoglossus]) and the H4B group (Hake [Urophycis spp.], Fourbeard Rockling [Enchelyopus cimbrius], and American Butterfish [Peprilus triacanthus]). Among the larvae collected, the most abundant species were Capelin (Mallotus villosus), Cunner, Radiated Shanny (Ulvaria subbifurcata), Atlantic Herring (Clupea harengus), and Atlantic Mackerel. Compared to the survey conducted in the same area in 2007, and omitting St. George’s Bay, the 2008 survey was characterized by a larger number of Atlantic Mackerel eggs and Capelin and Atlantic Herring larvae and a decrease in cod and righteye flounder larvae. Generalized additive models (GAM) have shown that the abundance of eggs and larvae of the primary species sampled could be described using a smoothing function based on longitude, latitude, their interaction, water temperature, and the abundance of Atlantic Mackerel eggs for larvae from this same species. From abundance measurements of all sampled larvae, cluster and ordination analyses revealed the presence of a spatial structure within the larval community. This was mainly characterized by Capelin, Cunner, and Atlantic Herring.

GRÉGOIRE, F., W. BARRY, J.-J. BARRY, J. BARRY, C. LÉVESQUE, J.-L. BEAULIEU, M.-H. GENDRON, 2011. West coast of Newfoundland Capelin (Mallotus villosus M.) and Atlantic Herring (Clupea harendus harengus L.) larval survey, part 7 : description of the data collected in partnership with the industry (Barry Group) in July 2008. Can. Data Rep. Fish. Aquat. Sci., 1235, 33 p .

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In partnership with the Barry Group, a larval survey was conducted on the west coast of Newfoundland from 16 to 18 July 2008 to measure the abundance of fish eggs and larvae sampled with plankton nets. A second objective was to describe the spatial distribution of fish larvae including those from two significant commercial species, Capelin (Mallotus villosus) and Atlantic Herring (Clupea harengus harengus). The two most abundant egg groups were the CYT group (Cunner [Tautogolabrus adspersus] and Yellowtail Flounder [Limanda ferruginea]) and the CHW group (Cod [Gadus morhua], Haddock [Melanogrammus aeglefinus], and witch Flounder (Glyptocephalus cynoglossus]). In addition, Atlantic Mackerel (Scomber scombrus) eggs were collected at all stations. Of the 16 larva species identified, the most abundant were capelin and cunner, followed by Radiated Shanny (Ulvaria subbifurcata), Atlantic Herring, Fourbeard Rockling (Enchelyopus cimbrius) and Atlantic Mackerel. Temperature and salinity profiles according to depth were made at each station. All biological and oceanographic data were collected and compiled and are presented in the tables, figures, and appendices in this document. These data will be analyzed and published in a forthcoming report.

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.

GRÉGOIRE, F., J.-L. BEAULIEU, 2011. Le hareng (Clupea harengus harengus L.) de la Côte-Nord du Québec (Division 4S de l'OPANO) en 2010 ; Atlantic herring (Clupea harengus harengus L.) on the Quebec North Shore (NAFO Division 4S) in 2010. MPO, Secrétariat canadien de consultation scientifique, Document de recherche ; DFO, Canadian Science Advisory Secretariat, Research Document, 2011/019, 108 p .

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Herring landings (Clupea harengus harengus L.) on the Quebec North Shore totaled 403 t in 2010 compared to 1,078 t in 2009. Most of these landings were made in unit areas 4Sz, 4Sv and 4Sw using traps, gillnets and purse seines. The trap and purse seine fisheries are usually carried out during the months of July and August, whereas the gillnet fishery takes place from April to August. Spring spawning herring dominate the landings made between April and June while fall spawners dominate those of July and August. Since the early 2000s, the two spawning groups have been characterized by a positive allometric growth and the presence of dominant year-classes. They have been observed for several consecutive years which suggests a low exploitation rate. Maturity at length has changed little over the years compared to a gradual decrease in length and average weight at age. This decrease suggests the presence of an inverse relationship between density and growth and/or environmental conditions that may have a negative impact on growth. Herring is a regular by-catch in the multidisciplinary groundfish and shrimp surveys in the northern Gulf of St. Lawrence. During these surveys, the probability of finding herring are generally very high (80-100 %) in the regions of Sept-Îles and Anticosti. The species’ dispersion, measured from these surveys’ data, increased significantly between 1997 and 2001, followed by a decline until 2008. The index has been increasing ever since. The abundance index, obtained from the acoustic survey conducted in unit area 4Sw in the fall of 2010, was estimated at 3,500 t for spring spawners and 80,855 t for fall spawners. Given these estimates, the low catch levels and the size of the area, an increase in the total allowable catch (TAC) could be permitted. However, currently available information can not accurately determine to what extent the TAC could be increased. Therefore, any increase in fishing effort on these two spawning stocks should be made gradually and be accompanied by close monitoring of catches (commercial and bait) and of biological characteristics.

GRÉGOIRE, F., W. BARRY, J. BARRY, C. LÉVESQUE, J.-L. BEAULIEU, M.-H. GENDRON, 2009. West coast of Newfoundland Capelin (Mallotus villosus M.) and Atlantic Herring (Clupea harengus harengus L.) larval survey, part 4 : abundance estimates and marine community analyses of the data collected in partnership with the industry (Barry Group) in July 2005. Can. Tech. Rep. Fish. Aquat. Sci., 2837, 51 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 2005. The survey’s two principal objectives were to describe the spatial distribution and measure the abundance of eggs and larvae of the principal fish species occurring in the study area. The most abundant eggs belonged to the CYT group (cunner [Tautogolabrus adspersus] and yellowtail flounder [Limanda ferruginea]) followed by the H4B group (hake [Urophycis spp.], fourbeard rockling [Enchelyopus cimbrus] and butterfish [Peprilus triacanthius]) and the CHW group (Atlantic cod [Gadus morhua], haddock [Melanogrammus aeglefinus] and witch flounder [Glyptocephalus cynoglossus]). Among the larvae collected, the most abundant species were cunner, capelin (Mallotus villosus), fourbeard rockling and blenny (Lumpenus spp.) followed by righteye flounder (Pleuronectidae), Atlantic cod, Atlantic mackerel (Scomber scombrus) and windowpane flounder (Scophthalmus aquosus). Compared with the survey conducted in the same area in 2004, the 2005 survey was characterized by a significant drop in Atlantic herring (Clupea harengus) larvae and an increase of capelin and Atlantic mackerel larvae. Cluster and ordination analyses revealed the presence of a structure within the larval community. Groups of stations were defined and characterized mostly by the occurrence of cunner and capelin. Significant temperature and salinity differences were recorded between these groups. However, these differences were not large enough to show a link between the specific larval composition for each group of stations and these two environmental variables.

GRÉGOIRE, F., C. LÉVESQUE, J.-L. BEAULIEU, M.-H. GENDRON, 2009. Pêche commerciale et biologie du maquereau bleu (Scomber scombrus L.) dans les sous-régions 3 et 4 de l’OPANO en 2007 ; Commercial fishery and biology of the Atlantic mackerel (Scomber scombrus L.) in NAFO Subareas 3 and 4 in 2007. MPO, Secrétariat canadien de consultation scientifique, Document de recherche ; DFO, Canadian Science Advisory Secretariat, Research Document, 2009/025, 166 p .

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In 2007, preliminary landings of Atlantic mackerel (Scomber scombrus L.) in the Northwest Atlantic totalled 75,863 t, which represents a decrease of 34,423 t from 2006 and 20,475 t from 2005. In eastern Canada, 50,578 t were landed with 44,032 t (87 %) in Newfoundland alone. The actual landings made in Canadian waters should be higher because fishery data from certain provinces were not all accounted for at the time of the assessment. In 2007, American landings totalled 25,285 t, a decrease of 31,352 t compared with 2006 and 15,732 t with 2005. The sharing of the resource based on historical landings and including the catches made by foreign vessels in American and Canadian waters would total 74 % in favour of the United States if this calculation were based on total landings made between 1960 and 2007. This proportion would be 51 % if the calculation were based on the average annual landings proportion of each country. When only considering domestic American and Canadian landings, these values would total 63 % and 70 % respectively in favour of Canada. In 2007, most of the landings off the west coast of Newfoundland were from unit areas 4Rb, 4Rc and 4Rd with respective totals of 7,100 t, 8,094 t and 8,039 t. On the east coast of Newfoundland, the most important landings were from unit areas 3Kh, 3Ki, 3La and 3Lb with respective values of 6,131 t, 1,483 t, 4,687 t and 5,511 t. Since the early 2000s, Canadian landings have been greatly dominated by fish from the 1999 year-class. Between 2000 and 2004, fish from this year-class have accounted for between 45 % and 77 % of all catches in numbers, which had not been observed since the late 1960s. Nevertheless, the relative significance of this year-class dropped sharply beginning in 2005 in favour of the 2003 year-class that accounted for 40 % of the 2007 landings. The strong 1999 year-class, which was responsible for landings of more than 150,000 t since 2000, is no longer an important contributor to the fishery or to the spawning stock. The strength of the year-classes since 1999 does not appear to be strong. Catches in the order of 50,000 t in recent years have been supported by this strong year-class. It is uncertain that catches of that level can be realized in the years to come with the year-classes presently available to the fishery.

GRÉGOIRE, F., W. BARRY, J. BARRY, O. GREGAN, C. LÉVESQUE, J.-L. BEAULIEU, M.-H. GENDRON, 2008. Évaluation de la biomasse reproductrice de maquereau bleu (Scomber scombrus L.) à partir des données des relevés d’ichtyoplancton réalisés sur la côte ouest de Terre-Neuve en 2004 et 2005 ; Assessment of the Atlantic mackerel (Scomber scombrus L.) spawning stock biomass from the data of the ichthyoplankton surveys made on the west coast of Newfoundland in 2004 and 2005. MPO, Secrétariat canadien de consultation scientifique, Document de recherche ; DFO, Canadian Science Advisory Secretariat, Research Document, 2008/039, 29 p .

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Ichthyoplankton surveys for describing distribution and calculating larvae abundance for pelagic fish were conducted on the west coast of in July 2004 and 2005. Atlantic mackerel (Scomber scombrus L.) larvae and eggs were collected at most of the stations sampled. Egg densities by station were converted in daily and total production and in spawning biomass according to the same analytical approach used for the abundance surveys conducted annually in the southern Gulf of St. Lawrence In 2004 and 2005, spawning biomasses were estimated respectively at 1,466 t and 5,692 t. These biomasses were only associated with the sampled area and the portion of the population that was spawning at the time of the surveys.

GRÉGOIRE, F., W. BARRY, J. BARRY, C. LEVESQUES, J.-L. BEAULIEU, M.-H. GENDRON, 2008. West coast of Newfoundland capelin (Mallotus villosus M.) and Atlantic herring (Clupea harengus harengus L.) larval survey. Part 5, Description of the data collected in partnership with the industry (Barry Group) in July 2007. Can. Data Rep. Fish. Aquat. Sci., 1205, 31 p .

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In partnership with the Barry Group in Comer Brook, a larval survey was conducted on the west coast of Newfoundland from July 18 to 21, 2007. Eggs and larvae of several ofspecies offish were found at all sampled stations. The two most abundant groups of eggs were CYT (cunner [Tautogolabrus adspersus] and yellowtail flounder [Limanda ferruginea]) and CHW (cod [Gadus morhua], haddock [Melanogrammus aeglefinus], and witch flounder [Glyptocephalus cynoglossus]). Mackerel eggs (Scomber scombrus) were found at most of the stations. Of the thirteen species of larvae identified, the most abundant were those of cunner, righteye flounder (Pleuronectidae) mackerel, fourbeard rockling (Enchelyopus cimbrus), and capelin (Mallotus villosus). Depth-based profiles of water temperature and salinity were made for each station. All the biological and oceanographic data collected during the survey were compiled and are presented in the tables, figures, and appendices found in this document. These data will be analyzed and published in a forthcoming report

GRÉGOIRE, F., C. LÉVESQUE, J.-L. BEAULIEU, C. MÉTHOT, M.-H. GENDRON, 2007. Résultats du relevé des œufs de maquereau bleu (Scomber scombrus L.) réalisé dans le sud du golfe du Saint-Laurent en 2006 ; Results of the Atlantic mackerel (Scomber scombrus L.) egg survey conducted in the southern Gulf of St. Lawrence in 2006. MPO, Secrétariat canadien de consultation scientifique, Document de recherche ; DFO, Canadian Science Advisory Secretariat, Research Document, 2007/073, 76 p .

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A survey for assessing the spawning biomass of Atlantic mackerel (Scomber scombrus L.) by egg sampling was conducted in the southern Gulf of St. Lawrence between June 28th and July 8th, 2006. Some very low egg abundance, less than 10 eggs/m2, was recorded at nearly 75 % of the sampled stations. The highest abundance was recorded at stations located west of the Magdalen Islands. These stations were associated to water temperatures (0-10 m layer) varying between 9.3 °C and 12.3 °C. The mean egg production for the entire sampled area was calculated at 7.4 eggs/m2, and total production at 5.12 x 1011 eggs. A spawning biomass of 54,133 t was associated with this egg production, which represented the lowest recorded value since 1979. The 2006 survey was conducted towards the end of the spawning season as indicated by the daily egg production curve, the high water temperatures, between 9.3 °C and 16.7 °C, and the presence of larvae at just about every station. When considering these results, the assessed biomass for 2006 is associated to the portion of the stock that reproduced at the very end of the spawning season rather than the entire stock. In order to improve the mackerel abundance assessment, it is suggested that the survey be conducted at more appropriate dates. The 2006 survey could not be conducted earlier due to a conflict in time management for vessels. It is also suggested that the survey cover the Scotian Shelf due to the recent changes in mackerel migration routes.

GRÉGOIRE, F., C. LÉVESQUE, J.-L. BEAULIEU, C. MÉTHOT, M.-H. GENDRON, 2007. Pêche et biologie du maquereau bleu (Scomber scombrus L.) des sous-régions 3 et 4 de l’OPANO en 2006 ; Atlantic mackerel (Scomber scombrus L.)fishery and biology for NAFO Subareas 3 and 4 in 2006. MPO, Secrétariat canadien de consultation scientifique, Document de recherche ; DFO, Canadian Science Advisory Secretariat, Research Document, 2007/067, 136 p .

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In 2006, preliminary landings of Atlantic mackerel (Scomber scombrus L.) in the Northwest Atlantic totalled 96,272 t, which represents a decrease of 66 t from 2005 and 12,547 t from 2004. In eastern Canada, 38,155 t were landed, with 34,884 t in Newfoundland alone. The actual landings made in Canadian waters in 2006 should be higher because fishery data from New Brunswick, Prince Edward Island and Nova Scotia were not all accounted for at the time of the assessment. In 2006, American landings totalled 58,117 t, an increase of 17,100 t compared with 2005. By considering the catches made by foreign vessels in American and Canadian waters, the sharing of the resource between both countries would total 75 % in favour of the United States if this calculation was based on total landings made between 1960 and 2005, and 52 % based on the average annual landings proportion of each country. When only considering domestic American and Canadian landings, these values would total 64 % and 70 % respectively in favour of Canada. Most of the landings off the west coast of Newfoundland were from unit areas 4Rd, 4Rb and 4Rc with respective totals of 8,159 t, 3,139 t and 2,617 t. On the east coast of Newfoundland, the most important landings were from unit areas 3Kh, 3Lb and 3Kd with respective values of 11,705 t, 3,265 t and 3,243 t. The other significant unit areas, with over 1,000 t each, were 3La on the east coast of Newfoundland and 4Tf in the Magdalen Islands with 1,912 t and 1,046 t respectively. Since the early 2000s, Canadian landings have been greatly dominated by fish from the 1999 year-class. Between 2001 and 2004, fish from this year-class have accounted for between 45 % and 77 % of all catches in numbers, which had not been observed since the late 1960s. Nevertheless, the relative significance of this year-class has dropped sharply in 2005 and 2006 in favour of the 2003 year-class. From 2002 to 2003, annual landings attributed to the 1999 year-class varied from 4,927 t to 35,970 t. They decreased from 30,792 t and 24,805 t in 2004 and 2005 to only 6,429 t in 2006. Although there are still uncertainties associated with fishery statistics, it appears that the dominant 1999 year-class no longer contributes very much to the fishery or to the reproductive stock. Therefore, total landings in 2007 are not likely to exceed that of recent years and the TAC, which far exceeds the highest recorded landings, should be brought back down to 50,000 t. However, it is highly likely that landings of this magnitude will not be sustainable if post-1999 year-classes are of only average abundance.

GRÉGOIRE, F., C. LÉVESQUE, J.L. BEAULIEU, J. HUDON, 2006. Évaluation de la biomasse reproductrice du maquereau bleu (Scomber scombrus L.) selon les relevés des œufs realisés en 2003, 2004 et 2005 ; Assessment of the Atlantic mackerel (Scomber scombrus L.) spawning stock biomass from the 2003, 2004, and 2005 egg surveys. MPO, Secrétariat canadien de consultation scientifique, Document de recherche ; DFO, Canadian Science Advisory Secretariat, Research Document, 2006/100, 48 p .

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The data that was collected during egg surveys conducted in the southern Gulf of St. Lawrence indicate a significant drop in mackerel spawning biomass since 2003. This drop could be caused above all by particular environmental conditions. In fact, for the surveys conducted since 2003, the most significant egg concentrations were found in only one small region located in the south-western part of the sampled area. This particular egg distribution pattern has never before been observed and would be associated with the presence of cold waters that covered an important portion of the Gulf of St. Lawrence during these surveys. These cold waters could also be the cause for recent changes in migration routes and the unusual and very abundant occurrence of mackerel on the east coast of Newfoundland. We recommend that the egg survey be extended outside the Gulf of St. Lawrence in order to improve the assessment of mackerel abundance. In addition, because of the recent increase in American and Canadian landings, we recommend an international egg survey between the Unites-States and Canada. This survey could be conducted periodically and cover the species’ two principal spawning grounds in the northwest Atlantic

GRÉGOIRE, F., C. LÉVESQUE, J.L. BEAULIEU, J. HUDON, 2006. Assessment of the Atlantic mackerel (Scomber scombrus L.) spawning stock biomass from the 2003, 2004, and 2005 egg surveys. DFO, Canadian Science Advisory Secretariat, Research Document, 2006/100, 48 p .

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The data that was collected during egg surveys conducted in the southern Gulf of St. Lawrence indicate a significant drop in mackerel spawning biomass since 2003. This drop could be caused above all by particular environmental conditions. In fact, for the surveys conducted since 2003, the most significant egg concentrations were found in only one small region located in the south-western part of the sampled area. This particular egg distribution pattern has never before been observed and would be associated with the presence of cold waters that covered an important portion of the Gulf of St. Lawrence during these surveys. These cold waters could also be the cause for recent changes in migration routes and the unusual and very abundant occurrence of mackerel on the east coast of Newfoundland. We recommend that the egg survey be extended outside the Gulf of St. Lawrence in order to improve the assessment of mackerel abundance. In addition, because of the recent increase in American and Canadian landings, we recommend an international egg survey between the Unites-States and Canada. This survey could be conducted periodically and cover the species’ two principal spawning grounds in the northwest Atlantic.

McQUINN, I.H., Y. SIMARD, T.W.F. STROUD, J.-L. BEAULIEU, S.J. WALSH, 2005. An adaptive, integrated "acoustic-trawl" survey design for Atlantic cod (Gadus morhua) with estimation of the acoustic and trawl dead zones. ICES J. Mar. Sci., 62(1): 93-106 .

The objectives of this study were to design an operationally efficient groundfish survey integrating both acoustic and trawl methodologies, to measure the changing vertical availability of cod to each method over 24 h and to compare cod-biomass estimates from the two methods within two experimental sub-regions. The two-phased sampling design involved (i) conducting an initial systematic acoustic survey to locate an area of high cod concentrations, (ii) using the acoustic-backscatter information to stratify the sub-regions into density strata for the allocation of trawl hauls, and (iii) conducting a second systematic acoustic survey at the same time as a random-stratified trawl survey. This protocol permitted the optimization of trawl sampling according to population density and the realization of simultaneous trawl and acoustic estimates for direct comparison. These cod showed extensive diel vertical migrations, which affected their availability to the trawl gear at night and the acoustic beam by day. An acoustic dead-zone correction was applied to the acoustic estimates, averaging 4-15 % of the biomass for the night-time transects and 11-36 % for the daytime transects. The detailed temporal acoustic monitoring of the vertical migrations permitted the quantification of the change in cod availability to the trawl gear. From 6 % to 47 % of cod were above the effective trawl height at night, while 0-10 % of cod were in the "trawl dead zone" by day. Estimated cod densities were very similar between the two methods on a haul-by-haul basis after correcting each method for their respective inherent sampling biases. The total biomass estimates were also comparable between the two methods for one sub-region, although significantly higher from the trawl data for the other. The discrepancies were most likely a result of differences in the sampling density of the two methods.©2004 Elsevier Ltd on behalf of International Council for the Exploration of the Sea

BEAULIEU, J.-L., 2001. Capelan de l'estuaire et du golfe du Saint-Laurent. Rapport sur l'état des stocks, B4-03, 8 p .

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BEAULIEU, J.-L., 2001. Description de la pêche au capelan (Mallotus villosus) dans l'estuaire et le golfe du Saint-Laurent (divisions 4RST) pour 1999 et 2000 ; The Capelin (Mallotus villosus) fishery in the estuary and gulf of St. Lawrence (Divisions 4RST) in 1999 and 2000. MPO, Secrétariat canadien de consultation scientifique, Document de recherche ; DFO, Canadian Science Advisory Secretariat, Research Document, 2001/048, 56 p .

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Annual variations observed in capelin landings are first and foremost triggered by market fluctuations. A change in market demand explains the nearly 50 % drop in landings observed in 1999 and 2000 as compared with the 1998 level. This decrease was especially noticeable in 4R, as this division has the largest capelin fishery in the Gulf of St. Lawrence. Purse seine is the gear type used for most catches in this division. The examination of median dates of annual landings in the purse seine fishery showed that fishing activities were delayed progressively between 1986 and 1992 in unit areas 4Rb, 4Rc and 4Rd. A regional pattern is also apparent as of 1993, and it is related to the fact that the earliest spawning occurs in 4Rd and the latest spawning in 4Rb. Based on commercial samples and compared with 1998 findings, the size of the fish declined in 1999, and then increased slightly in 2000. In the early 1990s, capelin showed a gradual decline in size, which led to a premature halt to fishing in 1994 and the nearly complete closure of the fishery in 1995. The increase in the percentage of occurrence of capelin computed from the groundfish abundance survey in the northern Gulf of St. Lawrence points to an extension of the species’ geographic range. Its range extension in the southern Gulf of St. Lawrence, which has been observed since the early 1990s, continued in 1999 and 2000. In view of capelin’s prominent role in the marine ecosystem, the lack of knowledge on its ecology and biology in the Gulf and the absence of an abundance survey for this species, any increase in catch levels must be limited and should be implemented gradually.

BEAULIEU, J.-L., 2001. Capelin of the Estuary and Gulf of St. Lawrence. Science, Stock Status Report, B4-03, 8 p .

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SIMARD, Y., I. McQUINN, M. MONTMINY, C. LANG, C. STEVENS, F. GOULET, J.-P. LAPIERRE, J.-L. BEAULIEU, J. LANDRY, Y. SAMSON, M. GAGNÉ, 2000. CH2 : Canadian Hydroacoustic data analysis tool 2 user's manual (version 2.0). Can. Tech. Rep. Fish. Aquat. Sci., 2332, 123 p .

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CH2 is the acronym for Canadian Hydroacoustic data analysis tool 2. It is a Windows 95 Multiple Document Interface (MDI) C++ application, developed by the Department of Fisheries and Oceans within the framework of the Data Analysis Tools (DAT) project of its National Hydroacoustic Program (NHP). It is dedicated to the display and processing of the standard HAC (Simard et al. 1997) multi-channel (multiple frequencies or beams) multi-echosounder acoustic data produced by the CH1 acquisition and real-time monitoring module (Simard et al. 1998). Data can originate from various analog or digital echosounders (e.g. Biosonics 102 type, Simrad EK500, or EY500). CH2 version 2.0 includes several editing TOOLS, to edit, eliminate, ignore, threshold, filter, or correct the raw HAC data, without erasing any original information. It also incorporates multi-channel classification tools, to partition the acoustic data into echo categories according to user decisions, and multi-channel echointegration capabilities for each echo category. The user can always track the various processing steps that have been applied to the original raw data. CH2 holds full undo and redo facilities for the various operations applied to the raw data. Edited files can be saved under the standard HAC format and contain the raw data plus the parameters of the editing/classification operations. The echointegration data are exported in ASCII text files that are directly usable by common data analysis or visualisation packages such as worksheets, statistical packages, and 2-D and 3-D mapping packages.

GRÉGOIRE, F., Y. SAMSON, J.-L. BEAULIEU, 1999. Résultats du relevé exploratoire d'hydroacoustique au capelan (Mallotus villosus) réalisé sur la côte ouest de Terre-Neuve en 1998. MPO, Secrétariat canadien pour l'évaluation des stocks, Document de recherche ; 99/10, 20 p .

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A capelin exploratory acoustic survey was conducted in 1998 on the west coast of Newfoundland. Between June 6 and June 10, 29 transects were completed and schools of fish were detected in each occasion. The schools were characterized by different geometries and those believed to be capelin were located between the thermoclin and the surface. It was not possible to determine the exact composition of these schools by the acquisition of commercial fish samples because the spawn and the fishery, which is directed essentially on mature females, were not started yet at the time of the survey.

RUNGE, J.A., M. CASTONGUAY, Y. De LAFONTAINE, M. RINGUETTE, J.-L. BEAULIEU, 1999. Covariation in climate, zooplankton biomass and mackerel recruitment in the southern Gulf of St. Lawrence. Fish. Oceanogr., 8: 139-149 .

CASTONGUAY, M., M. LEVASSEUR, J.-L. BEAULIEU, F. GRÉGOIRE, S. MICHAUD, E. BONNEAU, S.S. BATES, 1997. Accumulation of PSP toxins in Atlantic mackerel : seasonal and ontogenic variations. J. Fish Biol., 50: 1203-1213 .

BEAULIEU, J.-L., M. CASTONGUAY, M. LEVASSEUR, F. GRÉGOIRE, S. MICHAUD, E. BONNEAU, S.S. BATES, 1996. Rôle des toxines IPM (intoxication paralysante par les mollusques) dans une mortalité de maquereau bleu (Scomber scombrus) en Nouvelle-Écosse en 1993 ; Role of PSP (Paralytic Shellfish Poisoning) toxins in an Atlantic mackerel (Scomber scombrus) mortality in Nova Scotia in 1993. Rapp. can. ind. sci. halieut. aquat. ; Can. Ind. Rep. Fish. Aquat. Sci., 236, 17 p .

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A mortality of Atlantic mackerel reported in Cape Breton in May 1993 prompted us to determine if paralytic shellfish poisoning (PSP) toxins could be identified as a potential cause of the kill. Live and dead mackerel collected in nearby traps had similar levels of PSP toxins in their livers. Additional mackerel were sampled from the commercial fishery in the southern and northern Gulf of St. Lawrence from June to October 1993. The total amount of PSP toxin per liver increased gradually with the age and the length of the fish, showing that mackerel bioaccumulate PSP toxins in their livers throughout their life. The quantity of PSP toxins per liver also increased during the summer, indicating that mackerel become comtaminated during their summer stay in the Gulf of St. Lawrence. By storing toxins in the liver, mackerel become potential lethal PSP vectors to their natural predators. However, eating mackerel poses no risk for humans as long as viscera are not consumed.

CASTONGUAY, M., J.-L. BEAULIEU, 1993. Development of a hydroacoustic abundance index for mackerel in Cabot Strait. DFO, Atlantic Fisheries, Research Document, 93/12, 24 p .

BEAULIEU, J.-L., M. CASTONGUAY, J.-P. BOUDREAU, 1993. Essais de pêche au maquereau au chalut pélagique. Rapp. can. ind. sci. halieut. aquat., 216, 17 p .

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A fishing experiment for mackerel (Scomber scombrus) using a pelagic trawl equipped with a net positioning system was conducted in the Baie des Chaleurs on board the CSS Calanus II. From 20 to 24 August 1992, 8,900 (19,600 pounds) and 3,855 (8,500 pounds) kilograms of mackerel and herring were caught, respectively. Two thirds of herring catches were made at night. The mean length of mackerel captured was 334.4 mm with a range of 205 to 441 mm. Fuel cost could have been lower and mackerel catches higher if less time has been wasted travelling because of a lack of space to store the mackerel.

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

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