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LAPOUSSIÈRE, A., C. MICHEL, M. STARR., M. GOSSELIN, M. POULIN, 2111. Role of free-living and particle-attached bacteria in the recycling and export of organic material in the Hudson Bay system. J. Mar. Syst., 88: 434-445 .
This study investigates, for the first time, the role of free-living and particle-attached bacteria in the sinking export and recycling of organic matter in the Hudson Bay system (i.e. Hudson Bay, Hudson Strait, and Foxe Basin), a large subarctic estuarine system. During the late summers of 2005 and 2006, the abundance, cell size, nucleic acid content, and sinking velocity of free-living and particle-attached bacteria were studied simultaneously, using a new approach that combines the settling column method with flow cytometry. Biomass, production, and respiration of both types of bacteria were estimated using published models. Our results showed that particle-attached bacteria were, on average, twice as large as and contained 1.3 times more nucleic acid than free-living bacteria. Particle-attached bacteria also sank faster than predicted by Stoke's Law, with estimated sinking velocities comparable to those of chlorophyll a biomass and protist cells. Each individual cell of the particle-attached bacterial community had high carbon demand, but their low abundances (<3% of total bacterial numbers) resulted in low total carbon demand. Therefore, the main contributors to POC recycling were found to be free-living bacteria using the non-sinking dissolved organic material, which is released from particles due to the hydrolytic activity of particle-attached bacteria.© 2010 Elsevier B.V. All rights reserved.
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
FERLAND, J., M. GOSSELIN, M. STARR, 2011. Environmental control of summer primary production in the Hudson Bay system : the role of stratification. J. Mar. Syst., 88: 385-400 .
The influence of environmental factors on size-fractionated phytoplankton production and biomass (chlorophyll a) and community composition was examined in the Hudson Bay system (Hudson Bay, Hudson Strait, and Foxe Basin; HBS) during August 2004 and September 2005 and 2006. Significant variability in the vertical structure of the water column and melt season length was observed between years and between regions of the HBS. Even though there was no year-to-year variability in the phytoplankton production and biomass, we observed significant differences in the phytoplankton size structure and taxonomic composition between mid and late summer. For all years, phytoplankton production and biomass were lower in Hudson Bay (51–1217 mg C m-2 d-1; 11–57 mg chl a m-2) than in Hudson Strait (675–2740 mg C m-2 d-1; 28–97 mg chl a m-2). Negative correlation between primary production and stratification strength of the upper water column suggested nutrient limited primary production in Hudson Bay and the south shore of Hudson Strait. Stratification and nitrate concentration also explained the variability in the physiological state (i.e., production:biomass ratio) and size structure of phytoplankton communities between mid and late summer. Daily estimated summer primary production averaged 0.32 g C m-2 in Hudson Bay and 1.34 g C m-2 in Hudson Strait. Phytoplankton production in the HBS was largely dominated by ultraphytoplankton. On average, only ca. 30 % of total production was potentially exported from the euphotic zone. The dominance of flagellate-dominated community may explain the low export of matter and energy toward deeper waters and likely toward the upper trophic levels.©2011 Elsevier B.V.
SIBERT, V., B. ZAKARDJIAN, M. GOSSELIN, M. STARR, S. SENNEVILLE, Y. LECLAINCHE, 2011. 3D bio-physical model of the sympagic and planktonic productions in the Hudson Bay system. J. Mar. Syst., 88(3) 434-445 .
We present a first attempt of simulating the sympagic and planktonic production cycles in the Hudson Bay marine system (HBS) driven by ice cover duration and local hydrodynamics with the help of a 3D coupled biological-physical model. The simulation shows a marked spatial variability of ice and planktonic production and associated carbon fluxes, suggesting the co-existence of several sub-systems in the HBS. Among these, the "low ice-high mixing" Hudson Strait sub-system is characterized by high (low) planktonic (ice algae) production, with annual primary production reaching up to 150 g C m-2 y-1. In contrast, the "high ice-low mixing" conditions over Hudson Bay induce an annual primary production of ca. 10-40 g C m-2 y-1 with a strong and early ice algal bloom. New production generally prevails over the simulated system except along the coastal freshwater-influenced southeastern Hudson Bay and shallow Foxe Basin. In most of the HBS,summer conditions are characterized by the prominence of deep chlorophyll and biomass maxima (down to 60 m depth in the Hudson Bay) located near the nutricline. Finally, the residence time of the particulate organic matter and further export to the benthos appear driven by coupled advective and bathymetric effects.©2011 Elsevier B.V. All rights reserved. © 2011 Elsevier B.V. All rights reserved.
Accumulation of metabolic CO2 can acidify marine waters above and beyond the ongoing acidification of the ocean by anthropogenic CO2. The impact of respiration on carbonate chemistry and pH is most acute in hypoxic and anoxic basins, where metabolic CO<sub}2 accumulates to high concentrations. The bottom waters of the Lower St. Lawrence Estuary (LSLE), where persistently severe hypoxia has developed over the last 80 years, is one such case. We have reconstructed the evolution of pH in the bottom waters from historical and recent data, and from first principles relating the stoichiometry of CO2 produced to oxygen consumed during microbial degradation of organic matter. Based on the value of the atmospheric partial pressure of CO2 that best reproduces the preformed dissolved inorganic carbon concentration in the bottom waters, we estimate the average ventilation age of the bottom waters to be 16 ± 3 years. The pH of the bottom waters has decreased by 0.2 to 0.3 over the last 75 years, which is four to six times greater than can be attributed to the uptake of anthropogenic CO2. The pH decrease is accompanied by a decline in the saturation state with respect to both calcite and aragonite. As of 2007, bottom waters in the LSLE are slightly supersaturated with respect to calcite (Oc ≈ 1.06 ± 0.04) but are strongly undersaturated with respect to aragonite (Oa ≈ 0.67 ± 0.03).©2011 Taylor & Francis
MEI, S.-P., F.J. SAUCIER, V. LE FOUEST, B. ZAKARDJIAN, S. SENNEVILLE, H. XIE, M. STARR, 2010. Modeling the timing of spring phytoplankton bloom and biological production of the Gulf of St. Lawrence (Canada) : effects of colored dissolved organic matter and temperature. Cont. Shelf Res., 30(19): 2027-2042 .
The effects of colored dissolved organicmatter (CDOM) from freshwater runoff and seasonal cycle of temperature on the dynamic of phytoplankton and zooplankton biomass and production in the Gulf of St. Lawrence (GSL) are studied using a 3-D coupled physical-plankton ecosystem model.Three simulations are conducted: (1) the reference simulation based on Le Fouest et al. (2005), in which light attenuation by CDOM is not considered and maximum growth rate (μmax) of phytoplankton and zooplankton are not temperature-dependent (REF simulation); (2) light attenuation by CDOM is added to REF simulation (CDOM simulation); and (3) in addition to CDOM, the μmax of phytoplankton and zooplankton are regulated by temperature (CDOM+TEMP simulation). CDOM simulation shows that CDOM substantially reduces phytoplankton biomass and production in the Lower St. Lawrence Estuary (LSLE), but slightly reduces overall primary production in the GSL. In the LSLE, the spring phytoplankton bloom is delayed from mid-March to mid-April, resulted from light attenuation by CDOM.The CDOM+TEMP simulation shows that the spring phytoplankton bloom in the LSLE is further delayed to July, which is more consistent with observations. Annual primary production is reduced by 33 % in CDOM+TEMP simulation from REF and CDOM simulations. Zooplankton production is the same in all three simulations, and export of organic matter to depth is reduced in CDOM+TEMP simulation, suggesting that temperature controlled growth of phytoplankton and zooplankton enhances the coupling between primary production and zooplankton production under the seasonal temperature cycle of the GSL.©2010 Elsevier Ltd.
MUNDY, C.J., M. GOSSELIN, M. STARR, C. MICHEL, 2010. Riverine export and the effects of circulation on dissolved organic carbon in the Hudson Bay system, Canada. Limnol. Oceanogr., 55(1): 315-323 .
The distribution of dissolved organic carbon (DOC) in Hudson Bay (HB), Foxe Basin (FB), and Hudson Strait (HS) was examined during 01–14 August 2003. The HB system displayed relatively high DOC concentrations with medians of 109, 90, and 100 μmol L-1 for measurements made in HB, FB, and HS, respectively. Waters were significantly modified as they circulated through the HB system. An influence of marine-derived DOC was inferred for waters entering the system from northern HS and FB. The presence of a cold-water layer and elevated DOC concentrations observed in HB along the western coast and at depth was explained through either brine rejection and export of surface DOC to depth during sea ice formation or the decomposition of a settling algal bloom. As waters circulated in HB, an input of terrigenous DOC was the dominant modifying factor. In particular, DOC-laden rivers in southern HB increased the DOC concentration and then displayed a conservative behavior as water exited the bay along the southern coast of HS. Additionally, the late stages of ice melt observed during this study showed a significant dilution effect on surface DOC concentrations within eastern HB. Input and export of riverine DOC in the HB system was estimated at ˜ 5.5 Tg C yr-1, which is approximately 23 % of the annual DOC input from rivers draining directly into the central Arctic Ocean and therefore represents an important contribution of terrigenous carbon to northern seas.©2010 American Society of Limnology and Oceanography, Inc.
KUMIKO, A.-S., A. CLARKE, K. FALKNER, J. HAMILTON, E. PETER JONES, C. LEE, B. PETRIE, S. PRINSENBERG, M. STARR, P. YEATS, 2010. Calcium carbonate saturation states in the waters of the Canadian Arctic Archipelago and the Labrador Sea. J. Geophys. Res. (C Oceans), 115. art. no. C11021, 18 p .
Ocean acidification is predicted to occur first in polar oceans. We investigated the saturation state of waters with respect to calcite (Ocal) and aragonite (Oarg) in six sections along an Arctic outflow pathway through the Canadian Arctic Archipelago (CAA) and into the northwestern Atlantic using dissolved inorganic carbon and total alkalinity measurements from 2003 to 2005. The study area, a key region connecting the Arctic and the North Atlantic, includes Smith Sound, Barrow Strait, Baffin Bay, Davis Strait, Hudson Strait, and the Labrador Sea. The average Oarg in the Arctic outflow was 1.18 ± 0.17 in Barrow Strait and 1.31 ± 0.14 in Smith Sound, with areas where Oarg < 1. The Arctic outflow through the CAA has a high content of Pacific waters, which have a low saturation state. These waters can be traced along the western Baffin Bay to Davis Strait. South of Davis Strait, this outflow is modified by mixing with slope and offshore waters of Atlantic origin and with the outflow from Hudson Strait. Despite the mixing, low saturation state water can still be identified on the southern Labrador Shelf. The aragonite saturation horizon is found at ˜ 150 m in Barrow Strait; at 200 m in Baffin Bay, Davis Strait, and Hudson Strait; and at 2300 m in the Labrador Sea. This study provides baseline data of the saturation states for the waters of the CAA and the northwest Atlantic. It also illustrates the downstream evolution of low saturation state Arctic outflow in the northwest Atlantic.©2010 American Geophysical Union.
DUFOUR, R., H. BENOIT, M. CASTONGUAY, J. CHASSÉ, L. DEVINE, P. GALBRAITH, M. HARVEY, P. LAROUCHE, S. LESSARD, B. PETRIE, L. SAVARD, C. SAVENKOFF, L. ST-AMAND, M. STARR, 2010. Ecosystem status and trends report: Estuary and Gulf of St. Lawrence ecozone. Rapport sur létat et les tendances des écosystèmes : écozone de lestuaire et du golfe du Saint Laurent. DFO, Canadian Science Advisory Secretariat, Research Document ; MPO, Secrétariat canadien de consultation scientifique, Document de recherche; 2010/030, 193 p .
This document was produced under the umbrella of the national ecosystem status and trends report program and deal with the estuary and gulf of St.Lawrence ecozone. It is structured around the status and trends of some important marine species and physico-chemical variables of the ecosystem. The national ecosystem status and trends report will support prioruty-setting for a national biodiversity agenda and will integrate national and provincial exosystem-bases information. It will report on many large terrestrial and marine ecozones.
SIBERT, V., B. ZAKARDJIAN, F. SAUCIER, M. GOSSELIN, M. STARR, S.SENNEVILLE, 2010. Spatial and temporal variability of ice algal production in a 3D ice-ocean model of the Hudson Bay, Hudson Strait and Foxe Basin system. Polar Res., 23(3): 247-254 .
Primary production, the basic component of the food web and a sink for dissolved inorganic carbon, is a major unknown in Arctic seas, particularly ice algal production, for which detailed and comprehensive studies are often limited in space and time. We present here a simple ice alga model and its coupling with a regional 3D iceocean model of the Hudson Bay system (HBS),including Hudson Strait and Foxe Basin, as a first attempt to estimate ice algal production and its potential contribution to the pelagic ecosystem on a regional scale. The ice algal growth rate is forced by sub-ice light and nutrient availability, whereas grazing and ice melt control biomass loss from the underside of the ice. The simulation shows the primary role of sea-ice dynamics on the distribution and production of ice algae with a high spatio-temporal variability in response to the great variability of ice conditions in different parts of the HBS. In addition to favourable light and nutrient conditions, there must be a sufficient time lag between the onset of sufficient light and ice melt to ensure significant ice algal production. This suggests that, in the context of enhanced warming in Arctic and sub-Arctic regions, earlier melt could be more damaging for ice algal production than later freezing. The model also includes a particulate organic matter (POM) variable, fed by ice melting losses to the water column, and shows a large redistribution of the POM produced by the ice ecosystem on a regional scale. Organic matter (POM) variable, fed by ice melting losses to the water column, and shows a large redistribution of the POM produced by the ice ecosystem on a regional scale.©2010 Polar Research.
DUFOUR, R., H. BENOIT, M. CASTONGUAY, J. CHASSÉ, L. DEVINE, P. GALBRAITH, M. HARVEY, P. LAROUCHE, S. LESSARD, B. PETRIE, L. SAVARD, C. SAVENKOFF, L. ST-AMAND, M. STARR, 2010. Rapport sur l'état et les tendances des écosystèmes marins canadiens en 2010. MPO, Secrétariat canadien de consultation scientifique, Avis scientifique, 2010/030(révisé), 43 p .
DUFOUR, R., H. BENOIT, M. CASTONGUAY, J. CHASSÉ, L. DEVINE, P. GALBRAITH, M. HARVEY, P. LAROUCHE, S. LESSARD, B. PETRIE, L. SAVARD, C. SAVENKOFF, L. ST-AMAND, M. STARR, 2010. 2010 Canadian marine ecosystem status and trends report. Advis. Sec. Sci. Advis. Rep. 2010/030(Revised), 38 p .
POULIN, M., N. LUNDHOLM, L. BÉRARD-THERRIAULT, M. STARR, R. GAGNON, 2010. Morphological and phylogenetic comparisons of Neodenticula seminae (bacillariophyta) populations between the subarctic Pacific and the Gulf of St. Lawrence. Eur. J. Phycol., 45(2): 127-142 .
Neodenticula seminae is a very important member of modern diatom assemblages in the Bering Sea and at middle to high latitudes of the North Pacific. In the North Atlantic, this species was considered extinct until it was recorded in high abundance in the 2001 spring phytoplankton bloom of the Gulf of St. Lawrence, Eastern Canada. Here, we discuss some of the most distinctive features of its morphology, including variation in some characters between the subarctic Pacific and the Gulf of St. Lawrence specimens. Most importantly, we observed that the deck and basal ridges, and the solid-walled costae (formerly known as primary pseudosepta) characteristic of N. seminae were present in the subarctic Pacific material, but were absent or vestigial in the Gulf of St. Lawrence material and in cultures from both regions. This morphological variation was most likely due to differences in physicochemical water properties between the subarctic Pacific and the Gulf of St. Lawrence. Phylogenetic analyses of the internal transcribed spacer regions of the nuclear ribosomal DNA showed that the strains of N. Seminae collected in the Gulf of St. Lawrence and the subarctic Pacific clustered in two sister clades, but differed from each other only slightly more than the variation among the subarctic Pacific strains. These results confirmed the reappearance of N. Seminae in the NW Atlantic after an absence of ˜0.8 Ma. In addition, the phylogenetic analyses based on the large subunit of the nuclear ribosomal DNA positioned N. seminae firmly within the Bacillariaceae (i.e. diatoms with a fibulate raphe system) and proved a close relationship to species of Fragilariopsis.©2010 British Phycological Society
Initiated in 1991 in support of specific research projects, sampling at the Rimouski station located in the lower St. Lawrence estuary has continued for 18 years with more than 400 sampling sorties. The limited sampling protocol followed during the first years revealed the usefulness of such a monitoring project in describing seasonal and interannual patterns in plankton dynamics in the region. These results led to the long duration of the sampling at this station and eventually to its inclusion in the Atlantic Zone Monitoring Program (AZMP) starting in 2005. In addition to its contribution to the monitoring program, the sampling at the Rimouski station has supported several research activities related to key and emergent topics in biogeochemical oceanography. The maintenance of such a long-term time series has only been possible with the contribution of numerous people through the years.
LAVOIE, D., M. STARR, B. ZAKARDJIAN, P. LAROUCHE, 2007. Identification of ecologically and biologically significant areas (EBSA) in the Estuary and Gulf of St. Lawrence: primary production ; Identification de zones dimportance écologique et biologique (ZIEB) pour lestuaire et le golfe du Saint-Laurent: production primaire. DFO, Canadian Science Advisory Secretariat, Research Document ; MPO, Secrétariat canadien de consultation scientifique, Document de recherche, 2007/079, 33 p .
In this report, we analyse of a large set of chlorophyll a, nitrate, and primary production observations gathered from the early 70's as well as results from a 3D coupled physical-biological model to identify ecologically and biologically significant areas (EBSAs) for primary production in the Gulf and Estuary of St. Lawrence. High phytoplankton production and Chl a concentration are found successively in all regions of the Gulf and Estuary of St. Lawrence, and thus all regions are important for phytoplankton production at one time or another during the year. However, only a few regions stand out as EBSAs if we consider their importance on an annual basis, based on uniqueness and aggregation criteria as defined in CSAS Ecosystem Status Report 2004/006. The most important zones are the Lower Estuary, the Gaspé Current, and the Northwestern Gulf.
REID, P.C., D.G. JOHNS, M. EDWARDS, M. STARR, M. POULIN, P. SNOEIJS, 2007. A biological consequence of reducing Arctic ice cover : arrival of the Pacific diatom Neodenticula seminae in the North Atlantic for the first time in 800000 years. Global Change Biol., 13(9): 1910-1921 .
The Continuous Plankton Recorder survey has monitored plankton in the Northwest Atlantic at monthly intervals since 1962, with an interegnum between 1978 and 1990. In May 1999, large numbers of the Pacific diatom Neodenticula seminae were found in Continuous Plankton Recorder (CPR) samples in the Labrador Sea as the first record in the North Atlantic for more than 800000 years. The event coincided with modifications in Arctic hydrography and circulation, increased flows of Pacific water into the Northwest Atlantic and in the previous year the exceptional occurrence of extensive ice-free water to the North of Canada. These observations indicate that N. seminae was carried in a pulse of Pacific water in 1998/early 1999 via the Canadian Arctic Archipelago and/or Fram Strait. The species occurred previously in the North Atlantic during the Pleistocene from ˜1.2 to ˜0.8 Ma as recorded in deep sea sediment cores. The reappearance of N. seminae in the North Atlantic is an indicator of the scale and speed of changes that are taking place in the Arctic and North Atlantic oceans as a consequence of regional climate warming. Because of the unusual nature of the event it appears that a threshold has been passed, marking a change in the circulation between the North Pacific and North Atlantic Oceans via the Arctic. Trans-Arctic migrations from the Pacific into the Atlantic are likely to occur increasingly over the next 100 years as Arctic ice continues to melt affecting Atlantic biodiversity and the biological pump with consequent feedbacks to the carbon cycle.©2007 Blackwell Publishing Ltd.
[Abstract only available in French]
Le complexe de la baie dHudson (comprenant la baie dHudson, le détroit dHudson ainsi que le bassin de Foxe) représente probablement le plus grand estuaire nordique du monde. Cet estuaire est une composante importante du courant du Labrador qui exerce une influence prédominante sur le climat de la partie est de lAmérique du Nord. La dynamique de circulation des masses deau dans cette région nordique est fortement influencée par les écoulements deau douce provenant notamment des bassins de drainage de la baie dHudson et de larctique. Cette région abrite près de la moitié des populations Inuits du Nunavut et du Nunavik, et est caractérisée par une forte biodiversité reflétant linfluence significative des eaux arctiques et subarctiques de lAtlantique Nord. Cet écosystème nordique a été identifié comme un « point chaud » pour la conservation de la biodiversité marine, mais aussi comme lune des régions les plus sensibles aux changements et à la variabilité climatique. Afin de pouvoir détecter, comprendre, suivre et prédire les changements environnementaux dans cette région nordique, les scientifiques du MPO, région du Québec, ont initié en 2003 un programme de monitorage appelé MERICA-nord (pour études des MERs Intérieures du CAnada). Ce programme de monitorage complémente celui effectué dans la mer intérieure du golfe du Saint-Laurent (MERICA-sud). Dans sa conception, sa réalisation et son échantillonnage de base, ce programme de monitorage sinspire du Programme de Monitorage de la Zone Atlantique. Il accommode en plus plusieurs programmes de recherche associés qui sont effectués par des partenaires tant à linterne quà lexterne du MPO, comme par exemple le secteur universitaire. MERICA-nord est supporté par le Centre national dexcellence pour la recherche aquatique dans lArctique (N-CAARE en anglais). Un élément clé du programme est lintégration des besoins des scientifiques avec lexpertise et la capacité de support logistique de la Garde côtière canadienne; ce programme a en effet profité jusquà maintenant de temps de navire offert par la Garde côtière canadienne sur une base dopportunité. MERICA-nord permet finalement au MPO dassumer ses obligations nationales et internationales de base en ce qui concerne létude des milieux marins nordiques, afin de répondre aux enjeux sociaux et globaux émergents que soulèvent limpact de lactivité humaine (ex., les développements hydroélectriques) ou encore des changements climatiques. Dans ce contexte, lenvironnement du complexe de la baie dHudson est encore bien peu connu.
PEPIN, P., B. PETRIE, J.-C. THERRIAULT, S. NARAYANAN, G. HARRISON, J. CHASSÉ, E. COLBOURNE, D. GILBERT, D. GREGORY, M. HARVEY, G. MAILLET, M. MITCHEL, M. STARR, 2005. The Atlantic Zone Monitoring Program (AZMP) : review of 1998-2003. Can. Tech. Rep. Hydrogr. Ocean Sci., 242, 87 p .
We outline the results of the self-assessment by the Atlantic Zone Monitoring Program (AZMP) based on the milestrones set out in the original proposal and on a series of key issues identified during the Fifth Annual General Meeting of the Atlantic Zone Monitoring Program and supported by the Atlantic Science Directors. The report is divided into 12 sections which aim at providing an overview of the program's accomplishments, progress to date as well as identifying key concerns about maintaining current program activities and future developments. The report is capped with four sections that outline some of the benefits in the understanding and predictability of marine systems that have been derived from continued long-term monitoring activities.
HARVEY, M., M. STARR, 2005. 2003 state of the ocean: chemical and biological oceanographic conditions in the Estuary and Gulf of St. Lawrence. DFO, Canadian Science Advisory Secretariat, Science Advisory Report, 2005/053, 20 p .
HARVEY, M., M. STARR, 2005. État de l'océan en 2003: les conditions chimiques et biologiques dans l'estuaire et le golfe du Saint-Laurent. MPO, Secrétariat canadien de consultation scientifique, Avis scientifique, 2005/053, 20 p .
LE FOUEST, V., B. ZAKARDJIAN, F.J. SAUCIER, M. STARR, 2005. Seasonal versus synoptic variability in planktonic production in a high-latitude marginal sea: the Gulf of St. Lawrence (Canada). J. Geophys. Res. (C Oceans), 110, art. no C09012, 21 p .
The Gulf of St. Lawrence (Canada) is a subarctic marginal sea characterized by highly variable hydrodynamic conditions that generate a spatial heterogeneity in the marine production. A better understanding of physical-biological linkages is needed to improve our ability to evaluate the effects of climate variability and change on the gulf's planktonic production. We develop a three-dimensional (3-D) eddy permitting resolution physical-biological coupled model of plankton dynamics in the Gulf of St. Lawrence. The planktonic ecosystem model accounts for the competition between simplified herbivorous and microbial food webs that characterize bloom and post-bloom conditions, respectively, as generally observed in temperate and subarctic coastal waters. It is driven by a fully prognostic 3-D sea ice-ocean model with realistic tidal, atmospheric, and hydrological forcing. The simulation shows a consistent seasonal primary production cycle, and highlights the importance of local sea ice dynamics for the timing of the vernal bloom and the strong influence of the mesoscale circulation on planktonic production patterns at subregional scales.©2005 The American Geophysical Union
STARR, M., L. ST-AMAND, L. DEVINE, L. BÉRARD-THERRIAULT, P.S. GALBRAITH, 2004. State of phytoplankton in the Estuary and Gulf of St. Lawrence during 2003 ; État du phytoplancton dans lestuaire et le golfe du Saint-Laurent en 2003. DFO, Canadian Science Advisory Secretariat, Research Document ; MPO, Secrétariat canadien de consultation scientifique, Document de recherche, 2004/123, 35 p .
We reviewed information concerning the seasonal and interannual variations in the concentrations of chlorophyll a, nitrates, and silicates as well as the abundance of the major species of phytoplankton measured at three fixed stations (Rimouski, Anticosti Gyre, and Gaspé Current) and six sections crossing the Estuary and Gulf of St. Lawrence. We concentrated on conditions prevailing in 2003 but also compared those observations with previous information from the 1992-2002 period. In 2003, the initiation of the major phytoplankton bloom at Station Rimouski in the Lower St. Lawrence Estuary occurred in late May, which is one month earlier than usual. Excluding 2002, this continued a trend that began in 1998. This major shift in the timing of the phytoplankton cycle is believed to be due to the below-normal spring freshwater runoff that has been generally observed in the St. Lawrence basin since 1998. The average phytoplankton biomass during spring-summer 2003 at Station Rimouski was also higher compared to 1992-1994, 1996, 1998, and 2000-2002, but lower compared to 1995, 1997, and, more especially, to 1999. Spring-summer phytoplankton production measured at this station was also much higher in 2003 compared to the previous three years but lower than in 1999. At the Anticosti Gyre and the Gaspé Current stations, nitrate and silicate concentrations were high in late fall-winter and low in late spring-summer due to biological consumption by phytoplankton. For both stations, the reduction of nutrients in the surface layer during spring-summer was much more pronounced in 2003 compared to the 2000-2002 period. Thus based on the evolution of nutrients, phytoplankton production in the northwestern Gulf of St. Lawrence could have been higher in 2003 compared to the previous three years. This is consistent with data from Station Rimouski in the Lower St. Lawrence Estuary. Similarly, the surface nutrient levels in late winter 2003 were also higher in the southern and northeastern Gulf of St. Lawrence compared to the previous two years while levels were not markedly different for the late spring-summer period. This suggests again that the spring phytoplankton bloom in these regions was also more intense in 2003 compared to recent years. For a third consecutive year, the analysis of the phytoplankton community composition in 2003 revealed the presence of the diatom Neodenticula seminae in many areas of the Gulf of St. Lawrence, with concentrations up to 197 X 102 cells per litre. This phenomenon is unusual since this species is typically found in North Pacific waters. In the Atlantic Ocean, this species has only been recorded in middle to high latitude Quaternary sediments, dating from between 0.84 and 1.2 million years ago. It is proposed that this Pacific species was introduced naturally into the Gulf (across the Arctic, down the Labrador Current, and through Strait of Belle Isle) rather than via ballast waters. The invasion of N. seminae on the Atlantic coast is consistent with recent observations suggesting a greater influx of Pacific waters into the Atlantic.
HARVEY, M., M. STARR, 2003. État de l'océan en 2002 : les conditions océanographiques chimiques et biologiques dans l'estuaire et le golfe du Saint-Laurent. Rapport sur l'état des écosystèmes, 2003/007, 14 p .
HARVEY, M., M. STARR, 2003. 2002 state of the ocean : chemical and biological oceanographic conditions in the Estuary and Gulf of St. Lawrence. Science, Ecosystem Status Report, 2003/007, 13 p .
OUELLET, P., F. GRÉGOIRE, M. HARVEY, E. HEAD, B. MORIN, G. ROBERT, L. SAVARD, S. SMITH, M. STARR, D. SWAIN, 2003. Exceptional environmental conditions in 1999 in eastern Canadian waters and the possible consequences for some fish and invertebrate stocks. AZMP Bull. PMZA, 3: 21-27 .
[Abstract only available in French]
Plusieurs indicateurs des conditions atmosphériques indiquent que des températures de lair anormalement élevées en 1999 ont entraîné une réduction de la glace de mer en hiver et au printemps sur les plateaux continentaux de Terre-Neuve, du Labrador et de la Nouvelle-Écosse et une augmentation des températures de leau de surface sur lensemble de la zone Atlantique. Également, dautres indices indiquent que le cycle de production biologique (la floraison du phytoplancton) a été initié plus tôt en 1999 dans la plupart des régions de la zone. Ces conditions océanographiques exceptionnelles auraient eu des conséquences positives sur la production (ex. recrutement, croissance) de nombreux stocks de poissons et dinvertébrés dans lEst du Canada.
LE FOUEST, V., M. CHIFFLET, M. STARR, B. ZAKARDJIAN, F. SAUCIER, 2003. Toward Prediction of the Ecosystem: 3D Simulations of the Coupled Biological Production and Hydrodynamics in the Estuary and Gulf of St. Lawrence. AZMP Bull. PMZA, 3: 37-41 .
[Abstract only available in French]
Les variations spatio-temporelles dans la dynamique du plancton sont une caractéristique importante des écosystèmes marins et elles ontété liées aux variations dans le recrutement des espèces exploitables. Nous présentons ici les premiers essais dutilisation dun modèle tridimentionnel couplé physique-biologique pour simuler la variabilité observée dans lestuaire et le golfe du Saint-Laurent à laide des données générées par le Programme de Monitorage de la Zone Atlantique (PMZA). Ces résultats préliminaires indiquent que le modèle peut reproduire les cycles spatio-temporels moyens dans la production primaire, incluant les cycles diurnes, les effets des marées, des vents, du cycle saisonnier dans la circulation et la transformation des masses deau et des glaces de mer, et finalement des mélanges turbulents associés à ces cycles. Les données du PMZA constituent une ressource irremplaçable pour le développement et lamélioration des modèles biologiques et pour augmenter notre capacité à prédire les impacts des changements et des variations climatiques sur les écosystèmes marins.
STARR, M., L. ST-AMAND, L. DEVINE, L. BÉRARD-THERRIAULT, 2003. State of phytoplankton in the Estuary and Gulf of St. Lawrence during 2002 ; État du phytoplancton dans l'estuaire et le golfe du St-Laurent en 2002. DFO, Canadian Science Advisory Secretariat, Research Document ; MPO, Secrétariat canadien de consultation scientifique, Document de recherche, 2003/103, 29 p .
Information concerning the seasonal and interannual variations in the concentrations of chlorophyll a, nitrates, and silicates as well as the abundance of the major species of phytoplankton measured from three fixed stations (Rimouski, Anticosti Gyre and Gaspé Current) and six sections crossing the Estuary and Gulf of St. Lawrence was reviewed. The authors concentrated on conditions prevailing in 2002 but also compared those observations with previous information from the 1992-2001 period. In 2002, the initiation of the major phytoplankton bloom at Station Rimouski in the Lower St. Lawrence Estuary occurred in late June, which is near the historical mean date. This contrasts with observations made from 1998 to 2001, when the spring phytoplankton bloom began 6-8 weeks earlier than normal (mid to early May). The average phytoplankton biomass during spring-summer 2002 at Station Rimouski was also somewhat higher compared to 1992-1994, 1998, and 2000-2001, but much lower compared to 1995, 1997, and, more especially, to 1999. In the Anticosti Gyre and the Gaspé Current, the depletion of nutrients in the surface layer (0-50 m) during spring occurred later in 2002 compared to the 1996-2001 period, suggesting that phytoplankton growth was also initiated later in 2002 compared to recent years in the northwestern part of the Gulf of St. Lawrence. This was particularly true for the Gaspé Current. The reduction of nutrients in the surface layer during spring-summer was also somewhat more pronounced in 2002 compared to the 2000-2001 period but much less compared to 1999. Thus based on the evolution of nutrients, phytoplankton production in the northwestern Gulf of St. Lawrence could have been higher in 2002 compared to the previous two years but much lower than for 1999. This is consistent with data from Station Rimouski in the Lower St. Lawrence Estuary. For a second consecutive year, the analysis of community composition in 2002 revealed the massive presence of the diatom Neodenticula seminae in most areas of the Gulf of St. Lawrence, with concentrations up to 1 x 106 cells per litre. This phenomenon is unusual since this species is usually found in North Pacific waters. In the Atlantic Ocean, this species has only been recorded in middle to high latitude Quaternary sediments, dating from between 0.84 and 1.2 million years ago. It is proposed that this Pacific species was introduced naturally into the Gulf (across the Arctic, down the Labrador Current, and through Strait of Belle Isle) rather than via ballast waters. The return of N. seminae to the Atlantic coast is consistent with recent observations indicating a greater influx of Pacific waters into the Atlantic and the freshening of the North Atlantic waters. In late spring and early fall 2002, the chlorophyll levels were higher in the southern Gulf of St. Lawrence compared to the previous three years. In the eastern part of the Gulf, the chlorophyll and nitrate levels in the surface layer in late spring and fall 2002 were not notably different from those observed in 1999-2001.
HARVEY, M., M. STARR, 2002. État de l'océan en 2001 : les conditions chimiques et biologiques dans l'estuaire et le golfe du Saint-Laurent. Rapport sur l'état des stocks, G4-03, 14 p .
HARVEY, M., M. STARR, 2002. 2001 State of the ocean : chemical and biological oceanographic conditions in the Estuary and Gulf of St. Lawrence. Science, Stock Status Report, G4-03, 12 p .
IRIGOLEN, X., R.P. HARRIS, H.M. VERHEYE, P. JOLY, J. RUNGE, M. STARR, D. POND, D. CAMPBELL, R. SHREEVE, P. WARD, A.N. SMITH, H.G. DAM, W. PETERSON, V. TIRELLI, M. KOSKI, T. SMITH, D. HARBOUR, R. DAVIDSON, 2002. Copepod hatching success in marine ecosystems with high diatom concentrations. Nature, 419: 387-389 .
STARR, M., L. ST-AMAND, L. BÉRARD-THERRIAULT, 2002. State of phytoplankton in the Estuary and Gulf of St. Lawrence during 2001 ; État de phytoplancton dans l'estuaire et le golfe du Saint-Laurent en 2001. DFO, Canadian Science Advisory Secretariat, Research Document ; MPO, Secrétariat canadien de consultation scientifique, Document de recherche, 2002/067, 23 p .
We review the information concerning the seasonal and interannual variations in the concentrations of chlorophyll a, nitrates, and silicates as well as the abundance of the major species of phytoplankton measured from three fixed stations and six sections crossing the Estuary and Gulf of St. Lawrence. We focus on the conditions prevailing in 2001 but compare those observations with previous information from the period of 1992-2000. In 2001, the initiation of the spring phytoplankton bloom at Station Rimouski in the Lower St. Lawrence Estuary occurred in early May, that is, 6-8 weeks earlier than usual. This continued a trend that began in 1998. This major shift in the timing of the phytoplankton cycle is believed to be due to the below-normal spring freshwater runoff observed in the St. Lawrence basin since 1998. For the second consecutive year, the average phytoplankton biomass at Station Rimouski during spring-summer 2001 was much lower compared to the 1995-1999 period (except for 1998) but comparable to the 1992-1994 period. In particular, the phytoplankton biomass in July 2001 was much lower compared to our previous observations. This is believed to be due to a more intense mixing period in the Lower St. Lawrence Estuary in July 2001. In the Anticosti Gyre and the Gaspé Current, the reduction of nutrients in the surface layer during spring-summer-fall 2001 was much less pronounced compared to the 1996-1999 period (except for 1998). In the Gaspé Current, near-surface chlorophyll levels were also generally lower in 2001 compared to the previous two years. On the other hand, summertime chlorophyll levels in the Anticosti Gyre were higher in 2001 compared to those observed in 1997-2000. Satellite observations of sea surface chlorophyll concentrations indicate that the 2001 spring bloom occurred in late April for most areas of the Gulf of St. Lawrence. This contrasts with previous observations showing a greater spatial variability in the timing of the bloom. The analysis of community composition showed that the 2001 spring bloom over most of the Gulf was principally dominated by the diatom Neodenticula seminae. This is the first occurrence of this species in the Gulf of St. Lawrence; this species is usually found in North Pacific waters. This unusual event is consistent with recent observations indicating a greater influx of Pacific waters into the Atlantic Ocean (via the Bering Strait) and with hydrographic evidence of a major intrusion of Labrador Slope Water into the Gulf of St. Lawrence in 2001. In late spring 2001, the chlorophyll levels were extremely low for most areas of the Gulf of St. Lawrence. The highest levels were observed in the nutrient-rich waters of the St. Lawrence Estuary and Gaspé Current system. In the eastern and southern part of the Gulf, the chlorophyll and nitrate levels in the surface layer in late spring 2001 were not notably different than those observed in 1999-2000.
STARR, M., M. HARVEY, P.S. GALBRAITH, D. GILBERT, D. CHABOT, J.-C. THERRIAULT, 2002. Recent intrusion of Labrador Shelf waters into the Gulf of St. Lawrence and its influence on the plankton community and higher trophic levels. ICES C.M., 2002/N:16, 10 p .
STARR, M., M. HARVEY, 2002. L'état du plancton dans l'estuaire et le golfe du Saint-Laurent en 2001. Nouvelles de l'IML, 13(8): 3-7 .
THERRIAULT, J.-C., P.S. GALBRAITH, M. STARR, M. HARVEY, 2002. Intrusions of Labrador shelf waters into the Gulf of St. Lawrence and their potential influence on the plankton. AZMP Bull. PMZA, 2: 12-15 .
[Abstract only available in French]
Des données hydrographiques obtenues dans le golfe du Saint-Laurent (GSL) depuis 1996 suggèrent que les années 2001 et 2002 sont caractérisées par des intrusions particulièrement importantes d'eaux denses et froides provenant des côtes du Labrador. Ces intrusions ont significativement contribué aux températures estivales particulièrement basses de la couche intermédiaire froide (CIF) dans le GSL, en dépit de conditions hivernales relativement chaudes. Plusieurs changements dans la communauté planctonique peuvent être associés à ces intrusions d'eaux froides dans le Golfe. Le plus remarquable en 2001 est sans doute la première apparition en grande abondance de la diatomée Neodenticula seminae dans presque toutes les régions du Golfe. Ceci est très inhabituel parce que cette diatomée est normalement retrouvée dans le Pacifique Nord, et non pas dans le nord Atlantique. En raison de sa présence simultanée sur la côte du Labrador et dans le Golfe, il est fort probable que cette espèce du Pacifique ait été introduite dans le Golfe via le détroit de Belle-Isle par des processus d'advection à travers l'Arctique, en empruntant le courant du Labrador. Une autre observation qui supporte l'hypothèse d'une importante intrusion d'eaux froides dans le Golfe en 2001 est l'augmentation significative de l'abondance de l'amphipode arctique Themisto libellula. En effet, leur nombre qui passe de 0.17 ind.m-2 en septembre 2000 à 10 ind.m-2 en septembre 2001, ne peut être facilement expliqué que par cette intrusion. Ces introductions régulières d'espèces planctoniques arctiques dans le GSL ont probablement un impact significatif sur les niveaux supérieurs de la chaîne trophique tel que suggéré par la relation significative observée entre l'abondance annuelle moyenne de T. libellula et sa présence relative dans la diète de la morue entre 1996 et 2001.
B. PETRIE, J.-C. THERRIAULT, G. HARRISON, V. SOUKHOVTSEV, P. PEPIN, M. HARVEY, M. STARR, P. LAROUCHE, S. SAMEOTO, 2001. The Atlantic Zone Monitoring Program;Le programme de monitorage de la zone atlantique. AZMP Bull. PMZA, 1: 1-12 .
STARR, M., M. HARVEY, 2000. State of phytoplankton and zooplankton in the Estuary and northwestern Gulf of St. Lawrence during 1999. Science, Stock Status Report, C4-18, 8 p .
STARR, M., M. HARVEY, 2000. État du phytoplancton et du zooplancton dans l'estuaire et le nord-ouest du golfe du Saint-Laurent en 1999. Rapport sur l'état des stocks, C4-18, 9 p .
COMEAU, M., M. STARR, G.Y. CONAN, G. ROBICHAUD, J.-C. THERRIAULT, 1999. Fecundity and duration of egg incubation for multiparous female snow crabs (Chionoecetes opilio) in the fjord of Bonne Bay, Newfoundland. Can. J. Fish. Aquat. Sci., 56: 1088-1095 .
Multiparous female snow crabs (Chionoecetes opilio) were collected by trap and Nephrops trawl in the fjord of Bonne Bay, Newfoundland, between April 1988 and August 1992 to study the fecundity and embryonic development. A relationship was established between the color of the egg mass and embryonic development. Fecundity was positively correlated with carapace width. A female of 67 mm carapace width can produce up to about 54 000 eggs. Egg mortality over the incubation period could reach 21 %, being greater in large females. Based on the bimodal distributions of embryonic developmental stages observed in the study, the female reproductive cycle was determined as 2 years and females probably only hatch two broods in their lifetime. Eggs hatch mainly in May and June.
COMEAU, M., G.Y. CONAN, F. MAYNOU, G. ROBICHAUD, J.-C. THERRIAULT, M. STARR, 1998. Growth, spatial distribution, and abundance of benthic stages of the snow crab (Chionoecetes opilio) in Bonne Bay, Newfoundland, Canada. Can. J. Fish. Aquat. Sci., 55: 262-279 .
The growth and spatial distribution of postlarval snow crab (Chionoecetes opilio) from a relatively unexploitated stock in Bonne Bay, Newfoundland (Gulf of St. Lawrence), were described from the analysis of size distributions from trawls and a dredge sampled between 1988 and 1993. Immature crabs molted twice a year for instars I-V and then molted annually until females reached a terminal molt at maturity (instar X or XI) and males a juvenile stage (instar VIII). Thereafter, juvenile males could molt to another juvenile size, skip a molt, or achieve a terminal molt at the onset of the morphometric differentiation of their claws depending on the relative abundance of mature males. The life expectancy of females and males was 13 and 19 years, respectively. Males should recruit to the commercial size of 95 mm carapace width at instar XII, 9 years or more after settlement. Relative abundance of early benthic to commercial-size individuals suggests that small immature crabs (instar V) migrate from shallow rocky to deep muddy bottoms. The patchy spatial distribution observed for the snow crab appeared to be determined more by substrate and intraspecific factors than by depth. Seasonal movements to shallow waters by larger animals was related to density- and temperature-dependent factors associated with the reproductive and growth cycle.
COMEAU, M., G. ROBICHAUD, M. STARR, J.-C. THERRIAULT, G.Y. CONAN, 1998. Mating of snow crab Chionoecetes opilio (O. Fabricius, 1788) (Decapoda, Majidae) in the fjord of Bonne Bay, Newfoundland. Crustaceana, 71: 925-941 .
BAN, S., C. BURNS, J. CASTEL, Y. CHAUDRON, E. CHRISTOU, R. ESCRIBANO, S.F. UMANI, S. GASPARINI, F.G. RUIZ, M. HOFFMEYER, A. IANORA, H.-K. KANG, M. LAABIR, A. LACOSTE, A. MIRALTO, S. POULET, X. NING, V. RODRIGUEZ, J. RUNGE, J. SHI, M. STARR, S.-I. UYE, 1997. The paradoxe of diatom-copepod interactions. Mar. Ecol. Prog. Ser., 157: 287-293 .
STARR, M., J.A. RUNGE, J.-C. THERRIAULT, 1996. Harmful effects of certain diatoms on the reproductive success of copepods. Pages 128-134 in R.W. Penney (ed.). Proceedings of the Fifth Canadian Workshop on Harmful Marine Algae. Dept. of Fisheries and Oceans (Can. Tech. Rep. Fish. Aquat. Sci., 2138) .
CONAN, G.Y., M. STARR, M. COMEAU, J.-C. THERRIAULT, F.X. MAYNOU, I. HERNANDEZ, G. ROBICHAUD, 1996. Life history strategies, recruitment fluctuations, and management of the Bonne Bay Fjord Atlantic snow crab (Chionoecetes opilio). Pages 59-97 in High latitude crabs : biology, management and economics. Alaska Sea Grant College Program (Alaska Sea Grant report; 96-02) .
STARR, M., J.-C. THERRIAULT, G.Y. CONAN, M. COMEAU, G. ROBICHAUD, 1994. Is match/mismatch the universal ill fated mechanism de-regulating stock/recruitment models? Snow crab (Chionoecetes opilio) prove that some species may precisely sense optimal plankton production for a timely release of their larvae. ICES C.M., 1994/R:12, 20 p .
STARR, M., J.-C. THERRIAULT, G.Y. CONAN, M. COMEAU, G. ROBICHAUD, 1994. Larval release in a sub-euphotic zone invertebrate triggered by sinking phytoplankton particles. J. Plankton Res., 16: 1137-1147 .
STARR, M., J.H. HIMMELMAN, J.-C. THERRIAULT, 1993. Environmental control of green sea urchin, Strongylocentrotus droebachiensis, spawning in the St. Lawrence Estuary. Can. J. Fish. Aquat. Sci., 50: 894-901 .
STARR, M., J.H. HIMMELMAN, J.-C. THERRIAULT, 1992. Isolation and properties of a substance from the diatom Phaeodactylum tricornutum which induces spawning in the sea urchin Strongylocentrotus droebachiensis. Mar. Ecol. Prog. Ser., 79: 275-287 .
STARR, M., J.H. HIMMELMAN, J.-C. THERRIAULT, 1991. Coupling of nauplii release in the barnacles with phytoplankton blooms : a parallel strategy to that of spawning in urchins and mussels. J. Plankton Res., 13: 561-571 .
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