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Bibliography of the Maurice Lamontagne Institute

Jean-François ST-PIERRE

BROWMAN, H.I., J. YEN, D.M. FIELDS, J.-F. ST-PIERRE, A.B. SKIFTESVIK, 2011. Fine-scale observations of the predatory behaviour of the carnivorous copepod Paraeuchaeta norvegica and the escape responses of their ichthyoplankton prey, Atlantic Cod (Gadus morhua). Mar. Biol., 158(12): 2653-2660 .

Paraeuchaeta norvegica (8.5 mm total length) and yolk-sac stage Atlantic cod larvae (4 mm total length) (Gadus morhua) larvae were observed in aquaria (3 l of water) using silhouette video photography. This allowed direct observations (and quantitative measurement) of predator–prey interactions between these two species in 3-dimensions. Tail beats, used by cod larvae to propel themselves through the viscous fluid environment, also generate signals detectable by mechanoreceptive copepod predators. When the prey is close enough for detection and successful capture (approximately half a body-length), the copepod launches an extremely rapid high Reynolds number attack, grabbing the larva around its midsection. While capture itself takes place in milliseconds, minutes are required to subdue and completely ingest a cod larva. The behavioural observations are used to estimate the hydrodynamic signal strength of the cod larva’s tail beats and the copepod’s perceptive field for larval fish prey. Cod larvae are more sensitive to fluid velocity than P. norvegica and also appear capable of distinguishing between the signal generated by a swimming and an attacking copepod. However, the copepod can lunge at much faster velocities than a yolk-sac cod larva can escape, leading to the larva’s capture. These observations can serve as input to the predator–prey component of ecosystem models intended to assess the impact of P. norvegica on cod larvae.©2011 Springer

PLOURDE, S., G. WINKLER, P. JOLY, J.-F. ST-PIERRE, M. STARR, 2011. Long-term seasonal and interannuel variations of krill spawning in the lower St Lawrence Estuary, Canada, 1979-2009. J. Plankton Res., 33(5): 703-714 .

This study describes the long-term seasonal and interannual variations in krill spawning using abundance of krill eggs collected during an on-going long-term monitoring program at an anchor station in the lower St Lawrence Estuary from 1992 to 2009 and data collected in the same region in 1979 to 1980. The longterm seasonal semi-monthly climatology in egg abundance revealed that krill generally reproduced during two periods, i.e. in late spring (mid-May to late June) and in late summer (August to mid-September), when phytoplankton biomass in the upper 50 m was greater than 75 mg chlorophyll a m-2. The identification of krill eggs to the species level in 2007 revealed that Meganyctiphanes norvegica egg abundance was related to the biomass of phytoplankton averaged over the month prior to sampling, corresponding to the duration of one spawning cycle (two intermolt periods) known for this species. Overall krill egg abundance varied significantly between years, showing high abundance every 3–5 years with no long-term interannual trend. The annual mean egg abundance normalized for the duration of krill spawning showed the same interannual long-term pattern. Both egg abundance indices were independent of the annual phytoplankton biomass, indicating that interannual variations in krill spawning biomass would be the most likely candidate to explain interannual variability in egg abundance. We propose that such normalized annual egg abundance based on high-resolution seasonal sampling could be a useful index of interannual variations in krill spawning biomass which is otherwise difficult to sample.©2011 Oxford University Press

DUNBRACK, R., L.A. GIGUE, J.-F. ST-PIERRE, 2009. A comparison of gut evacuation models for larval mackerel (Scomber scombrus) using serial photography. J. Fish. Biol., 74(4): 906-920 .

A novel technique is described, using serial photography of the gut contents of transparent living larval fishes, to generate individual gut evacuation time series. This technique was applied to Atlantic mackerel Scomber scombrus larvae to compare three widely used models of gut evacuation: linear, exponential and square-root. Regression r2 for the exponential model exceeded those for the linear and square root models in 20 of 21 time series, strongly supporting the exponential model. At the initial gut fullness for each time series, total gut evacuation rates calculated with the exponential model averaged 2·2 and 1·3 times greater than those calculated with the linear and square-root models, respectively, and would produce correspondingly higher estimates of feeding rates for field-collected larvae with similar levels of gut fullness. The results highlight the importance of choosing the appropriate evacuation model in feeding studies, particularly those intended to examine short-term changes in larval fish feeding rates, a contributing factor to the highly variable yearly recruitment of many marine fish species.©2009 The Fisheries Society of the British Isles

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).

GALBRAITH, P., H.I. BROWMAN, R.G. RACCA, A.B. SKIFTESVIK, J.-F. SAINT-PIERRE, 2004. Effect of turbulence on the energetics of foraging in Atlantic cod Gadus morhua larvae. Mar. Ecol. Prog. Ser., 281: 241-257 .

A net energy gain (NEG) model was used to assess the effects of turbulence on the energy budget of Atlantic cod Gadus morhua larvae, feeding on copepod nauplii at different concentrations.The geometry of their prey search space was parameterised as either a sphere, hemisphere (the most commonly applied in analogous studies), or wedge. Observed distributions in behaviour (e.g. move duration, pause duration, turn angles) were used as model input, and 2 facets of this behaviour (move duration and move speed) were varied to examine how parameterised changes in foraging behaviour can affect the NEG of the predator. At a prey concentration of 100 l-1, and in static water, NEG is an order of magnitude higher for a hemispherical shape relative to a wedge-shaped search volume. This difference decreases with increasing prey concentration (600 l-1), but always remains considerable. When parameterised turbulence was added, prey capture rates for a larva with a hemispherical search space increases 3 times as much as for a larva with a wedge-shaped search space (typically a 50 % increase using the hemisphere vs 15 % using a wedge). Thus, when this one key assumption (the search volume shape) of current turbulence-effects models is more realistically parameterised, the theorized advantage of turbulence is greatly reduced (at the level of the animal’s prey capture and NEG). This result demonstrates the need to carefully reassess the underlying assumptions of current turbulence-effects models and, therefore, the conclusions that have been based upon those models. Our NEG model also demonstrates the energetic benefits of certain changes in larval behaviour—such as shorter move durations—which lead to a more thorough and cost-effective search of the surrounding water for larvae with a wedge-shaped search volume. This latter effect is not observed for predators with spherical or hemispherical search volumes. These results indicate that it would be prudent to reconsider the conclusions of any previous study that was based upon over-simplified search space geometries. ©2004 Inter-Research

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.

BROWMAN, H.I., J.-F. ST-PIERRE, A.B. SKIFTESVIK, R.G. RACCA, 2003. Behaviour of Atlantic cod (Gadus morhua) larvae : an attempt to link maternal condition with larval quality. Pages 72-95 in H.I. Browman, J.-F. St-Pierre, A.B. Skiftesvik & R.G. Racca. Behaviour of Atlantic cod (Gadus morhua) larvae: an attempt to link maternal condition with larval quality. The Big Fish Bang. .

SKIFTESVIK, A.B., H.I. BROWMAN, J.-F. ST-PIERRE, 2003. Life in green water : the effect of microalgae on the behaviour of Atlantic cod (Gadus morhua) larvae. Pages 97-103 in A.B. Skiftesvik & H.I. Browman (éd.). The Big Fish Bang .

BROWMAN, H.I., J.-F. ST-PIERRE, P. KUHN, 2003. Dose and dose-rate dependency in the mortality response of Calanus finmarchicus embryos exposed to ultraviolet radiation. Mar. Ecol. Prog. Ser., 247: 297-302 .

BROWMAN, H.I., R.D. VETTER, C.A. RODRIGUEZ, J.J. CULLEN, R.F. DAVIS, E. LYNN, J.-F. ST-PIERRE, 2003. Ultraviolet (280-400 nm)-induced DNA damage in the eggs and larvae of Calanus finmarchicus G. (Copepoda) and Atlantic Cod (Gadus morhua). Photochem. Photobiol., 77(4): 397-404 .

HARVEY, M., J.-F. ST-PIERRE, P. JOLY, G. MORRIER, 2002. Oceanographic conditions in the Estuary and the Gulf of St. Lawrence during 2001 : zooplankton ; Conditions océanographiques dans l'estuaire et le golfe du St-Laurent en 2001 : zooplancton. DFO, Canadian Science Advisory Secretariat, Research Document ; MPO, Secrétariat canadien de consultation scientifique, Document de recherche, 2002/046, 30 p .

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This report: 1) describes the results on the temporal variability of the zooplankton biomass, abundance, and species composition at two fixed stations and six transects of the Atlantic Zonal Monitoring Program (AZMP; Anticosti Gyre and Gaspé Current) in 2001 and 2) gives an overview of the interannual variability of the macrozooplankton species composition, abundance, and biomass in the Lower St. Lawrence Estuary and the northwest Gulf of St. Lawrence (GSL) as measured in September in each year between 1994 and 2001. We focus on the conditions during 2001 but compare those observations with previous information from 1999 and 2000 for the AZMP results and from 1994 to 2001 for the macrozooplankton results.

RODRIGUEZ, C.A., H.I. BROWMAN, J.A. RUNGE, J.-F. ST-PIERRE, 2000. Impact of solar ultraviolet radiation on hatching of a marine copedod, Calanus finmarchicus. Mar. Ecol. Prog. Ser., 193: 85-93 .

RODRIGUEZ, C.A., H.I. BROWMAN, J.-F. ST-PIERRE, 2000. High survival of neustonic zoea I larvae of American lobster Homarus americanus following short-term exposure to ultraviolet (280 to 400 nm). Mar. Ecol. Prog. Ser., 193: 305-309 .

HARVEY, M., J.A. RUNGE, J.-F. ST-PIERRE, P. JOLY, 2000. Oceanographic conditions in the Estuary and the Gulf of St. Lawrence in 1999 : zooplankton. DFO, Canadian Stock Assessment Secretariat, Research Document ; MPO, Secrétariat canadien de consultation scientifique, Document de recherche, 2000/117, 19 p .

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This report describes : 1) an overview of the spatial variability of the mesozooplankton and krill biomass in the lower St. Lawrence Estuary and the northwest Gulf of St. Lawrence (GSL) measured in September in each year between 1994-1999 and 2) results on the temporal variability of the zooplankton biomass, abundance, and species composition at two fixed stations of the Atlantic Zonal Monitoring Program (AZMP; Anticosti Gyre and Gaspé Current) in 1999. Within the lower St. Lawrence Estuary and the northwest GSL, the biomass of mesozooplankton and krill was not evenly distributed and showed very high interannual variability. The estimated average wet biomass of mesozooplankton varied between 106.5 and 209.2 t km-2 from 1994 to 1999 with the highest and the lowest values found in 1994 and 1996 respectively. From 1994 to 1999, the overall average biomass of mesozooplankton for the whole lower St. Lawrence Estuary and northwest GSL was estimated at 1.6 106 ±  0.3 106 t. Likewise, the estimated average biomass of krill varied between 7.2 and 38.1 t km-2 from 1994 to 1999 with the highest and the lowest values found in 1994 and 1996 respectively. The overall average biomass of krill for the whole lower St. Lawrence Estuary and northwest GSL was estimated to be 1.7 105 ± 0.9 105 t. The temporal variability of the zooplankton biomass, abundance, and species composition at the two AZMP fixed stations (Anticosti Gyre and Gaspé Current) showed that copepods were clearly dominant at all sampling dates in 1999, accounting for more than 80 % of the zooplankton community for both stations. Small copepods (Oithona similis, Oncea borealis) dominated in abundance at all sampling dates at both stations except in the Gaspé Current in July and August, where larger species (Calanus finmarchicus, C. glacialis, Metridia longa) were more abundant. Total zooplankton biomass was much higher in the Anticosti Gyre than in the Gaspé Current for all seasons in 1999 except in May, when the biomass was equal at both stations. The integrated copepod abundance showed the same pattern of variation with season at both stations, with a maximum abundance of copepod eggs in spring and a maximum abundance of adult copepods and copepodite stages (CI-CV) in late fall. The total integrated abundance of adult copepods and copepodite stages (CI-CV) did not vary significantly between stations for all seasons. Finally, all proposed indices describing the state of the zooplankton community at each station in 1999 varied with season and their annual mean values varied between stations. However, it is too soon to say if they will be useful to describe the interannual variability of the zooplankton community or to detect any changes of the environmental conditions.

BROWMAN, H.I., C.A.RODRIGUEZ, F. BÉLAND, J.J. CULLEN, R.F. DAVIS, J.H.M. KOUWENBERG, P.S. KUHN, B. McARTHUR, J.A. RUNGE, J.-F. ST-PIERRE, R.D. VETTER, 2000. Impact of ultraviolet radiation on marine crustacean zooplancton and ichthyoplankton : a synthesis of results from the estuary and Gulf of St. Lawrence, Canada. Mar. Ecol. Prog. Ser., 199: 293-311 .

KOUWENBERG, J.H.M., H.I. BROWMAN, J.A. RUNGE, J.J. CULLEN, R.F. DAVIS, J.-F. ST-PIERRE, 1999. Biological weighting of ultraviolet (280-400 nm) induced mortality in marine zooplankton and fish. II, Calanus finmarchicus (Copepoda) eggs. Mar. Biol., 134: 285-293 .

KOUWENBERG, J.H.M., H.I. BROWMAN, J.J. CULLEN, R.F. DAVIS, J.-F. ST-PIERRE, J.A. RUNGE, 1999. Biological weighting of ultraviolet (280-400 nm) induced mortality in marine zooplankton and fish. I, Atlantic cod (Gadus morhua) eggs. Mar. Biol., 134: 269-284 .

KUHN, P., H.I. BROWMAN, B. McARTHUR, J.-F. ST-PIERRE, 1999. Penetration of ultraviolet radiation in the waters of the Estuary and Gulf of St. Lawrence. Limnol. Oceanogr., 44: 710-716 .

BÉLAND, F., H.I. BROWMAN, C.A. RODRIGUEZ, J.-F. ST-PIERRE, 1999. Effect of solar ultraviolet radiation (280-400 nm) on the eggs and larvae of Atlantic cod (Gadus morhua). Can. J. Fish. Aquat. Sci., 56: 1058-1067 .

In the Gulf of St. Lawrence, Canada, solar ultraviolet B radiation (UV-B, 280-320 nm) penetrates a significant percentage of the summer mixed-layer water column : organisms residing in this layer : such as the eggs of Atlantic cod (Gadus morhua), are exposed to UV-B. IN outdoor exposure experiments, Atlantic cod eggs were incubated in the presence versus the absence of UV-B and (or) UV-A (320-400 nm). We tested two hypotheses : H1, UV-B induces mortality in Atlantic cod eggs, and H2, UV-A either exacerbates or mitigates any such UV-B-induced mortality. Hypothesis H1 was supported : there was a significant mortality effect on Atlantic cod eggs exposed to UV-B at the surface and at a depth of 50 cm. Hypothesis H2 was not supported : there was no effect of UV-A. These experiments indicate that Atlantic cod eggs present in the first metre ot fhe water column (likely only a small percentage of the total egg population) are susceptible to UV-B. However, UV-B must be viewed as only one among many environmental factors that produce the very high levels of mortality typically observed in the planktonic early life stages of marine fishes.

ST-PIERRE, J.-F., J. RUNGE, P. JOLY, Y. DE LAFONTAINE, 1996. Données physiques, chimiques et biologiques sur le plancton du nord du golfe du Saint-Laurent. Partie 1 : juin 1989. Rapp. stat. can. sci. halieut. aquat., 986, 99 p .

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This report forms part of a study of the trophic interactions in the pelagic ecosystem of the north-central Gulf of St. Lawrence. The data presented here were collected during two simultaneous research cruises in the northern Gulf of St. Lawrence in June 1989. Measured variables include salinity; temperature; light extinction; nutrient concentrations; particulate carbon and nitrogen concentrations; size-fractionated chlorophyll a concentrations; abundance, composition and vertical distribution of phytoplankton, microzooplankton and mesozooplankton; copepod egg production rates; and the composition, abundance, vertical distribution, size, and diet of redfish larvae (Sebastes fasciatus-mentella). The methods used to obtain this information are described. The study focuses in particular on the interaction between microplankton, the dominant planktonic copepod, Calanus finmarchicus, and larval redfish, which dominate the ichthyoplankton

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 .

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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.

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.

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) .

GIGUÈRE, L.A., J.-F. ST-PIERRE, B. BERNIER, A. VÉZINA, J.-G. RONDEAU, 1989. Can we estimate the true weight of zooplankton samples after chemical preservation?. Can. J. Fish. Aquat. Sci., 46: 522-527 .

GIGUÈRE, L.A., B. CÔTÉ, J.-F. ST-PIERRE, 1988. Metabolic rates scale isometrically in larval fishes. Mar. Ecol. Prog. Ser., 50: 13-19 .

We estimated the rate of oxygen consumption of larval Atlantic mackerel Scomber scombrus at 3 temperatures (13, 16, 19 °C while controlling rigorously for methodological biases. Routine metabolic rates (µl O 2h-1ind.-1) increase with body weight (W, in mg) and temperature (T, in °C) as : RMR=2.168•W1.000•e0.058•T(r2=0.96). Thus metabolic rates scale isometrically with respect to body weight in larval Atlantic mackerel. This finding is at variance with results obtained for juvenile and adult fishes which follow an allometric relationship (W0.8).©1988 Inter-Research