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Bibliography of the Maurice Lamontagne Institute

Yves GAGNON

HARVEY, M., J.-F. ST-PIERRE, L. DEVINE, A. GAGNÉ, Y. GAGNON, M.F. BEAULIEU, 2005. Oceanographic conditions in the Estuary and the Gulf of St. Lawrence during 2004 : zooplankton ; Conditions océanographiques dans l’estuaire et le golfe du St-Laurent en 2004 : zooplancton. DFO, Canadian Science Advisory Secretariat, Research Document ; MPO, Secrétariat canadien de consultation scientifique, Document de recherche, 2005/043, 22 p .

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Zooplankton biomass, abundance, and species composition in the Québec Region (Lower St. Lawrence Estuary and Gulf of St. Lawrence) during 2004 are reviewed and related to conditions during the preceding years and over the longer term where applicable. In addition, this report gives an overview of the interannual variability of the mesozooplankton biomass and the macrozooplankton species composition, abundance, and biomass in the Lower Estuary (LE) and the northwest Gulf of St. Lawrence (NWGSL) as measured in fall of each year between 1994 and 2004. Even with only four zooplankton samples collected in February, March, June and November 2004, at both Québec fixed stations in 2004, we can see that the zooplankton biomass follow the same temporal variations pattern then during the 5 previous years (1999-2003). Furthermore, the zooplankton biomass observed in February, March, June and November were comparable to the one observed previously (1999-2003) at the same period of the year except in June and November in the Anticosti gyre were the zooplankton biomass was ca 2 times lower than normal. Hierarchical community analysis revealed that copepods continue to numerically dominate the zooplankton year-round at both Québec fixed station in 2004. The depth-integrated abundance of the different Calanus finmarchicus stages reveled that the reproductive success of C. finmarchicus seems to have been lower in 2004 than during the previous years at both fixed stations. The overall abundance and biomass of zooplankton observed in 2004 along all sections in spring and fall were comparable to observations made since 2000. The mean mesozooplankton biomass observed in November 2004 in the LE and the NWGSL was 1.3 times lower than in 2003 and corresponded to the second lowest value observed since the last 10 years in the study area. On the other hand, the mean macrozooplankton biomass observed in 2004 was 1.2 times higher than in 2003. The most notable feature observed in the LE and the NW GSL was that 2004 had the lowest mean biomass of euphausiids in the last decade and that for the first time the mean biomass of the hyperiid amphipod T. libellula was higher than the mean biomass of euphausiids. Finally, the mean abundance of both the chaetognaths and the jellyfish observed in 2004 corresponded to the highest value of the time series and were up 8.5 and 10.5 times higher than the average value of the last ten years respectively.

HARVEY, M., J.-F. ST-PIERRE, L. DEVINE, A. GAGNÉ, Y. GAGNON, M.F. BEAULIEU, 2004. Oceanographic conditions in the Estuary and the Gulf of St. Lawrence during 2003: zooplankton ; Conditions océanographiques dans l’estuaire et le golfe Saint-Laurent en 2003: zooplancton. DFO, Canadian Science Advisory Secretariat, Research Document ; MPO, Secrétariat canadien de consultation scientifique, Document de recherche, 2004/061, 31 p .

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Zooplankton biomass, abundance, and species composition in the Québec Region (Lower St. Lawrence Estuary and Gulf of St. Lawrence) during 2003 are reviewed and related to conditions during the preceding years and over the longer term where applicable. In addition, this report gives an overview of the interannual variability of the mesozooplankton biomass and the macrozooplankton species composition, abundance, and biomass in the Lower Estuary and the northwest Gulf of St. Lawrence as measured in September of each year between 1994 and 2003. The zooplankton biomass and abundance at the Québec fixed stations in 2003 were slightly higher than observations made in 2000, 2001, and 2002 at both stations. The relative proportion of copepods vs. the other groups of mesozooplankton increased from 70 to 95 % between 1999 and 2003 in the Gaspé Current (GC) and from 70 to 85 % between 1999 and 2001 in the Anticosti Gyre (AG). No larvacea were found at both fixed stations in 2003. The depth-integrated abundance of the Calanus finmarchicus stage composition showed that there were two periods of reproduction for this species at both stations in 2003. Reproduction occurred in summer (June-July) and fall (September-October) and was synchronized at both stations. The same situation was observed in 2000, 2001, and 2002. In 2003, the abundance of Calanus finmarchicus reached record high level since 1999 at both fixed stations (GC and AG). The zooplankton biomasses and abundances observed in early spring, late spring, and fall 2003 along the six AZMP sections were comparable to observations made in 2002, 2001, and 2000. The mesozooplankton biomass in the Lower Estuary and the northwest Gulf of St. Lawrence in 2003 was slightly higher than in 2002 while the macrozooplankton biomass was comparable to the 2002 level. The year 2003 was characterized by a significant increase in the mean abundance of the pelagic amphipod Themisto libellula and the mysid Boreomysis arctica and a significant decrease in the mean abundance of the chaetognath Sagitta elegans and the gelatinous zooplankton Aglantha digitale, Obelia spp., and Boreo spp. The significant relationships between the mean annual abundance of the hyperiid amphipod T. libellula and the percentage of Labrador Shelf water supported the hypothesis that the significant increase in the mean abundance of this species observed in 2001, 2002, and 2003 in the Lower Estuary and the Gulf of St. Lawrence is associated with the intrusion of the cold Labrador Shelf water into the Gulf of St. Lawrence via the Strait of Belle Isle (Harvey et al 2003).

HARVEY, M., J.-F. ST-PIERRE, A. GAGNÉ, M.F. BEAULIEU, Y. GAGNON, 2003. Oceanographic conditions in the Estuary and the Gulf of St. Lawrence during 2002 : zooplankton ; Conditions océanographiques dans l’estuaire et le golfe du St-Laurent en 2002 : zooplancton. DFO, Canadian Science Advisory Secretariat, Research Document ; MPO, Secrétariat canadien de consultation scientifique, Document de recherche, 2003/077, 23 p .

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Zooplankton biomass, abundance, and species composition in the Québec region (Lower St.Lawrence Estuary and Gulf of St. Lawrence) during 2002 are reviewed and related to conditions during the preceding year and over the longer-term where applicable. In addition, this report gives an overview of the interannual variability of the mesozooplankton biomass and the macrozooplankton species composition, abundance, and biomass in the Lower Estuary and the northwest Gulf of St. Lawrence as measured in September in each year between 1994 and 2002. The zooplankton biomass and abundance in the Québec fixed stations in 2002 were comparable to conditions observed in previous years except in the Gaspé current were the mean integrated zooplankton biomass was 1.5 times higher in 2002 than in 2001 and 2000. Copepod eggs, juveniles, and adults were clearly dominant, accounting for more than 80% of the zooplankton community for all sampling dates in the Anticosti Gyre and the Gaspé Current. The depthintegrated abundance of the stage composition of Calanus finmarchicus showed that in 2002 there was two periods of reproduction for this species in both stations. The first and the second period of reproduction occurred in summer (June-July) and fall (September-October) respectively and were synchronized in both stations. The same situation was observed in 2001 and 2000. The zooplankton biomasses observed in spring and fall 2002 along the six AZMP sections were comparable with observations made in 2001 and 2000. The zooplankton abundance was higher than in 2001 in both the LSLE and the Gulf of St. Lawrence but comparable to the levels observed in 2000. The mesozooplankton biomass in the Lower Estuary and the northwest Gulf of St. Lawrence in 2002 was slightly higher than in 2001 while the macrozooplankton biomass was comparable to the level of 2001. The year 2002 was characterized by a significant increase of the mean abundance the chaetognath Sagitta elegans, the gelatinous zooplankton Aglantha digitale, Obelia sp., and Boreo sp., and the pelagic amphipod Themisto abyssorum and a significant decrease of the mean abundance of the mysid Boreomysis arctica.

FRÉCHET, A., Y. GAGNON, P. SCHWAB, D. D'AMOURS, J.-D. DUTIL, Y. LAMBERT, L. BOURASSA, C. ROLLET, 1994. Revue de l'état du stock de morue du nord du golfe du Saint-Laurent (3Pn, 4RS) en 1993 ; Review of the status of the northern Gulf of St. Lawrence cod stock (3Pn, 4RS) in 1993. MPO, Pêches de l'Atlantique, Document de recherche ; DFO, Atlantic Fisheries, Research document, 94/29, 50 p .

The 1993 fishing season was conducted with many problems. The fishing season started late because of problems linked with enforcement, the fisheries were stopped many times because of small fish. The initial TAC for 1993 of 31,000 t was reduced at the end of August to 18,000 t on the recommendation of the FRCC. This TAC was based on results of last year's assessment and corresponds to a fishery at the F0.1 reference level. Landings for 1993 were of 18,171 t. There are no directed nor sport fisheries on the 3Pn, 4Rs cod stock in 1994. All available indices indicate a large decline in the last year. The mobile gear catch rates drop by 37 % between 1992 and 1993. The population estimates derived from the 1994 January groundfish research vessel survey represent only 51 % of those estimated in 1993. The population estimates from the summer groundfish survey dropped by 65 %. Catch rates from the Index Fishermen declined in certain cases and maintained themselves in others. For the first time, a calibration of SPA was attempted incorporating results from both the summer and winter surveys. The summer survey series is now long enough to be of interest (4 years) and the winter series will be discontinued in 1995. The 3+ population numbers would have gone from 546 million individuals in 1980 to as low as 95 million individuals in 1993 and the biomass of mature fish (7+) in 1993 could be as low as 10,000 t. Because of problems linked with the quality of the research vessel survey information, the calibration with ADAPT produces anomalously high fishing mortalities. The analysis is thus presented for illustrative purposes only and no projections were done. Biomass is expected to be very low.

FRÉCHET, A., Y. GAGNON, 1993. Assessment of the biomass of the northern Gulf of St. Lawrence cod stock (3Pn, 4RS) in 1992. DFO, Atlantic Fisheries, Research Document, 93/68, 42 p .

FRÉCHET, A., Y. GAGNON, 1993. Évaluation de la biomasse du stock de morue du nord du golfe du Saint-Laurent (3Pn, 4RS) en 1992. MPO, Document de recherche sur les pêches dans l'Atlantique, 93/68, 42 p .

Landings from the 3Pn, 4Rs cod stock for the 1992 fishing season were 29,000 t while the TAC was set at 35,000 t. These are the lowest landings for this stock since 1961. Landings from the fixed gear sector have, in contrast with last year, decreased to reach 8,818 t. For the mobile gear sector, landings were 20,946 t, the lowest since 1961. This is mostly due to a substantial decrease in their allocation because of a reduced TAC. The abundance estimate from the January 1993 survey is lower than the 1992 estimate. However, some uncertainties remain because of the effect of possible influx of the 3Pn, 4Rs cod stock into Subdivision 3Ps. The sequential population analysis was calibrated with abundance estimates of the winter survey. Results indicate that biomass would have doubled between 1974 and 1983 but has declined to a level lower than 1974 in 1993. Results of projections at the reference catch level F0,1 for 1994 would be 20,000 t.