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Yves DE LAFONTAINE
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 .
ST-PIERRE, J.-F., Y. De LAFONTAINE, 1995. Fecundity and reproduction characteristics of beaked redfish (Sebastes fasciatus and S. mentella) in the Gulf of St. Lawrence. Can. Tech. Rep. Fish. Aquat. Sci., 2059, 32 p .
This study is designed to quantify environmental perturbations arising from forest harvesting operations and investigate the ability to ameliorate these perturbations through the provision of an unharvested leave strip of varying widths along riparian zones. This initial report from this research project is intended to document background information on the study. The report includes a general description of the study site, identifies the roles and objectives of the various study participants, outlines the general study design, and provides some detail on the various study components and methods to be employed.
De LAFONTAINE, Y., 1994. Zooplankton biomass in the southern Gulf of St. Lawrence : spatial patterns and the influence of freshwater runoff. Can. J. Fish. Aquat. Sci., 51: 617-635 .
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) .
PEPIN, P., T. SHEARS, Y. De LAFONTAINE, 1992. Significance of body size to the interaction between a larval fish (Mallotus villosus) and a vertebrate predator (Gasterosteus aculeatus). Mar. Ecol. Prog. Ser., 81: 1-12 .
De LAFONTAINE, Y., 1992. A workshop on juvenile stages : searching for the missing link in fisheries research. Pages 3-11 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) .
De LAFONTAINE, Y., T. LAMBERT, G.R. LILLY., W.D. McKONE, R.J. MILLER (éd.), 1992. Les stades juvéniles : le chaînon manquant en recherche sur les pêches : rapport d'atelier de travail, 1-3 octobre 1991, Bedford Institute of Oceanography, Dartmouth, Nova Scotia ; Juvenile stages : the missing link in fisheries research : report of a workshop 1-3 October, 1991, Bedford Institute of Oceanography, Dartmouth, Nova Scotia. Rapp. tech. can. sci. halieut. aquat. ; Can. Tech. Rep. Fish. Aquat. Sci., 1890, 139 p .
Under the auspices of the Marine Environment and Ecosystems Subcommittee (MEES) of the Canadian Atlantic Fisheries Scientific Advisory Committee (CAFSAC), a 3-day workshop on the juvenile stages of commercially important marine fish and invertebrates was held in Darmouth, N.S., in October 1991. The objectives of the workshop were to review the present status of research on juvenile stages for fisheries management and to provide recommendations for future research on juvenile stages as an index of recruitment. The first part of the workshop was dedicated to an overview of research activities through the presentation of new or unreported results on the ecology of juvenile stages. This report presents the extended abstracts of the contributed papers which embraced both vertebrate and invertebrate research studies. During the second part of the workshop, participants were divided into four working groups to formulate recommendations on four discussion topics previously defined. Recommendations of each working group were reviewed by all participants during a general discussion. The discussion reports of each working group are presented here. The final recommendations and the generalizations of the steering committee are also included.
LEGENDRE, L., K. JUNNIPER, D. BOOTH, A. CEMBELLA, Y. DE LAFONTAINE, J. GAGNÉ, W.G. HARRISON, S. ROY, B. SAINTE-MARIE, A. SINCLAIR, R. TRITES, A.F. VÉZINA, 1991. Report of the Workshop on Biological Oceanography. Pages 23-30 in J.-C. Therriault (ed.). The Gulf of St. Lawrence : small ocean or big estuary ? Dept. of Fisheries and Oceans (Can. Spec. Publ. Fish. Aquat. Sci., 113) .
LEGENDRE, L., K. JUNNIPER, D. BOOTH, A. CEMBELLA, Y. DE LAFONTAINE, J. GAGNÉ, W.G. HARRISON, S. ROY, B. SAINTE-MARIE, A. SINCLAIR, R. TRITES, A.F. VÉZINA, 1991. Rapport de l'atelier de travail sur l'océanographie biologique. Pages 23-30 in J.-C. Therriault (éd.). Le golfe du Saint-Laurent : petit océan ou grand estuaire? Ministère des pêches et des océans (Publ. spéc. can. sci. halieut. aquat., 113) .
ST-PIERRE, J.-F., Y. De LAFONTAINE, 1991. Bibliography of the biological oceanography for the Gulf of St. Lawrence. Pages 335-359 in J.-C. Therriault (ed.). The Gulf of St. Lawrence : small ocean or big estuary ? Dept. of Fisheries and Oceans (Can. Spec. Publ. Fish. Aquat. Sci., 113) .
ROCHE-MAYZAUD, O., J.-C. THERRIAULT, J.A. RUNGE, Y. De LAFONTAINE, 1991. Variations de l'activité des enzymes digestives et de la ponte chez les femelles de Calanus finmarchicus dans le golfe du Saint-Laurent. Pages 231-240 in J.-C. Therriault (éd.). Le Golfe du Saint-Laurent : petit océan ou grand estuaire? Ministère des pêches et des océans (Publ. spéc. can. sci. halieut. aquat., 113) .
De LAFONTAINE, Y., S. DEMERS, J. RUNGE, 1991. Pelagic food web interactions and productivity in the Gulf of St. Lawrence : a perspective. Pages 99-123 in J.-C. Therriault (ed.). The Gulf of St. Lawrence : small ocean or big estuary ? Dept. of Fisheries and Oceans (Can. Spec. Publ. Fish. Aquat. Sci., 113) .
De LAFONTAINE, Y., 1990. Ichthyoplankton communities in the St. Lawrence Estuary : composition and dynamics. Pages 321-343 in M.I. El-Sabh & N. Silverberg (ed.). Oceanography of a large-scale estuarine system : the St. Lawrence. Springer-Verlag, Berlin (Coastal and Estuarine Studies, 39) .
De LAFONTAINE, Y., 1990. Distribution and abundance of ichthyoplankton in the Manicouagan River estuary, a tributary of the Lower St. Lawrence Estuary. Estuaries, 13: 43-50 .
De LAFONTAINE, Y., D. GASCON, 1989. Ontogenetic variation in the vertical distribution of eggs and larvae of Atlantic mackerel (Scomber scombrus). Rapp. P-v. Réun. CIEM, 191: 137-145 .
De LAFONTAINE, Y., W.C. LEGGETT, 1989. Changes in size and weight of hydromedusae during formalin preservation. Bull. Mar. Sci., 44: 1129-1137 .
De LAFONTAINE, Y., W.C. LEGGETT, 1988. Predation by jellyfish on larval fish : an experimental evaluation employing in situ enclosures. Can. J. Fish. Aquat. Sci., 45: 1173-1190 .
Large in situ enclosures were used to investigate the mortality of yolk-sac larval capelin (Mallotus villosus) by four species of jellyfish predators. Daily instantaneous larval mortality increased linearly with predator density but was independent on initial density, indicating a linear functional response of the four jellyfish species.The addition of alternative prey did not modify the linearity of the functional response and did not significantly reduce or increase larval mortality imposed by two jellyfish species. The evidence of linear response in large enclosures contrasts with the curvilinear (Type II) response previously reported in studies conducted in small laboratory containers. Larval mortality was strongly dependent on predator size within jellyfish species and increase with initial larval size. Larval capelin appeared more susceptible to predation at the time of transition from endogenous to exogenous feeding. Daily larval mortality rates due to predation varied between 0.015 and 1.58 depending on jellyfish species and appeared more strongly determined by body mass than differences in feeding appendages of jellyfish. Our results indicate that reduced laval mortality to jellyfish predation is achievable only by timing larval release in water mass where jellyfish numbers are naturally reduced. We estimated that macro invertebrate predation has the potential of being the primary regulator of larval survival and we hypothesized that large intra- and interannual variation in larval survival may be due to the variability in the emergence timing of capelin larvae relative to the growth trajectory of jellyfish.
De LAFONTAINE, Y., W.C. LEGGETT, 1987. Effect of container size on estimates of mortality and predation rates in experiments with macrozooplankton and larval fish. Can. J. Fish. Aquat. Sci., 44: 1534-1543 .
We investigated the effect of container size on the predation rate of the jellyfish Aurelia aurita on postemergent capelin (Mallotus villosus) larvae in large in situ cylindrical enclosures. Total depth of the enclosures varied between 1 and 9 m and yielded volumes that ranged from 0.26 to 6.35 m3. Instantaneous mortality rates of capelin larvae due to jellyfish predation varied inversely and nonlinearly with the volume of the enclosure. Over the range of container sizes used, mortality rates different by one order of magnitude. Container volume explained 80 % of the variance in mortality rates, while predator size and larval size accounted for 8.3 and 2.3% of the variability, respectively. Mortality rate was independent of the initial larval density within each container size. Differences in mortality rates among container size are explained by the observed differences in the vertical patchiness of larvae among various enclosure sizes. These findings indicate that experiments conducted in small containers typical of those used in laboratory studies seriously overestimate rates of larval mortality due to predation. Direct extrapolation of the results of such laboratory studies to field conditions is therefore not warranted. We conclude that the vertical distributions of predator and prey may be the most important factor controlling predator-prey relationships in situ.
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