Personne : Archambault, Philippe
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Université Laval. Département de biologie
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Publication Accès libreGreen Edge ice camp campaigns : understanding the processes controlling the under-ice Arctic phytoplankton spring bloom(Göttingen Copernicus Publications, 2020-01-27) Massicotte, Philippe; Amiraux, Rémi; Amyot, Marie-Pier; Archambault, Philippe; Aubry, Cyril; Ayotte, Pierre; Bécu, Guislain; Bélanger, Simon; Bruyant, Flavienne; Christiansen-Stowe, Debra; Coupel, Pierre; Dezutter, Thibaud; Dominé, Florent; Dufour, Francis; Dufresne, Christiane; Dumont, Dany; Ferland, Joannie; Forget, Marie-Hélène; Fortier, Louis; Galí, Martí; Galindo, Virginie; Gourdal, Margaux; Grondin, Pierre-Luc; Guillot, Pascal; Guilmette, Caroline; Lacour, Léo; Lagunas, José Luis; Lalande, Catherine; Laliberté, Julien; Lambert Girard, Simon; Larivière, Jade; Lavaud, Johann; LeBaron, Anita; Lemire, Mélanie; Levasseur, Maurice; Marec, Claudie; Massé, Guillaume; Matsuoka, Atsushi; Neukermans, Griet; Oziel, Laurent; Rehm, Eric Carl; Reimer, Erin; Saint-Béat, Blanche; Sansoulet, Julie; Tremblay, Jean-Éric; Verin, Gauthier; Babin, MarcelThe Green Edge initiative was developed to investigate the processes controlling the primary productivity and fate of organic matter produced during the Arctic phytoplankton spring bloom (PSB) and to determine its role in the ecosystem. Two field campaigns were conducted in 2015 and 2016 at an ice camp located on landfast sea ice southeast of Qikiqtarjuaq Island in Baffin Bay (67.4797∘ N, 63.7895∘ W). During both expeditions, a large suite of physical, chemical and biological variables was measured beneath a consolidated sea-ice cover from the surface to the bottom (at 360 m depth) to better understand the factors driving the PSB. Key variables, such as conservative temperature, absolute salinity, radiance, irradiance, nutrient concentrations, chlorophyll a concentration, bacteria, phytoplankton and zooplankton abundance and taxonomy, and carbon stocks and fluxes were routinely measured at the ice camp. Meteorological and snow-relevant variables were also monitored. Here, we present the results of a joint effort to tidy and standardize the collected datasets, which will facilitate their reuse in other Arctic studies. Publication Accès libreMachine Learning for underwater laser detection and differentiation of macroalgae and coral(Frontiers Media S.A., 2023-06-01) Huot, Matthieu; Dalgleish, Fraser; Beauchesne, David; Piché, Michel; Archambault, PhilippeA better understanding of how spatial distribution patterns in important primary producers and ecosystem service providers such as macroalgae and coral are affected by climate-change and human activity-related events can guide us in anticipating future community and ecosystem response. In-person underwater field surveys are essential in capturing fine and/or subtle details but are rarely simple to orchestrate over large spatial scale (e.g., hundreds of km). In this work, we develop an automated spectral classifier for detection and classification of various macroalgae and coral species through a spectral response dataset acquired in a controlled setting and via an underwater multispectral laser serial imager. Transferable to underwater lidar detection and imaging methods, laser line scanning is known to perform in various types of water in which normal photography and/or video methods may be affected by water optical properties. Using off the shelf components, we show how reflectance and fluorescence responses can be useful in differentiating algal color groups and certain coral genera. Results indicate that while macroalgae show many different genera and species for which differentiation by their spectral response alone would be difficult, it can be reduced to a three color-type/class spectral response problem. Our results suggest that the three algal color groups may be differentiated by their fluorescence response at 580 nm and 685 nm using common 450 nm, 490 nm and 520 nm laser sources, and potentially a subset of these spectral bands would show similar accuracy. There are however classification errors between green and brown types, as they both depend on Chl-a fluorescence response. Comparatively, corals are also very diverse in genera and species, and reveal possible differentiable spectral responses between genera, form (i.e., soft vs. hard), partly related to their emission in the 685 nm range and other shorter wavelengths. Moreover, overlapping substrates and irregular edges are shown to contribute to classification error. As macroalgae are represented worldwide and share similar photopigment assemblages within respective color classes, inter color-class differentiability would apply irrespective of their provenance. The same principle applies to corals, where excitation-emission characteristics should be unchanged from experimental response when investigated in-situ. Publication Accès librePredator traits determine food-web architecture across ecosystems(Springer Nature, 2019-05-20) Brose, Ulrich; Archambault, Philippe; Legagneux, Pierre; Iles, Alison C.Predator–prey interactions in natural ecosystems generate complex food webs that have a simple universal body-size architecture where predators are systematically larger than their prey. Food-web theory shows that the highest predator–prey body-mass ratios found in natural food webs may be especially important because they create weak interactions with slow dynamics that stabilize communities against perturbations and maintain ecosystem functioning. Identifying these vital interactions in real communities typically requires arduous identification of interactions in complex food webs. Here, we overcome this obstacle by developing predator-trait models to predict average body-mass ratios based on a database comprising 290 food webs from freshwater, marine and terrestrial ecosystems across all continents. We analysed how species traits constrain body-size architecture by changing the slope of the predator–prey body-mass scaling. Across ecosystems, we found high body-mass ratios for predator groups with specific trait combinations including (1) small vertebrates and (2) large swimming or flying predators. Including the metabolic and movement types of predators increased the accuracy of predicting which species are engaged in high body-mass ratio interactions. We demonstrate that species traits explain striking patterns in the body-size architecture of natural food webs that underpin the stability and functioning of ecosystems, paving the way for community-level management of the most complex natural ecosystems. Publication Accès libreAutocueillette durable et sécuritaire de moules bleues du Saint-Laurent en collaboration avec les Wolastoqiyik Wahsipekuk (Québec, Canada)(Les Éditions en environnement VertigO, 2021-05-17) Lefebvre, Marie-Claude; Archambault, Philippe; Truchon-Savard, Alexandre; Weiner, Guy-Pascal; Grant, Cindy; Hennigs, Rebecca; Desmarais-Lacourse, Isadora; Lemire, MélanieLes membres de la Première Nation Wolastoqiyik Wahsipekuk basée à Cacouna aimeraient pouvoir cueillir et consommer les moules bleues présentes en abondance sur les rives de l’estuaire du Saint-Laurent dans leur territoire ancestral. Cependant, les lois fédérales communiquées par des affiches de Pêches et Océans Canada en interdisent la cueillette. Un projet pilote a alors été créé entre la Première Nation et le collectif Manger notre Saint-Laurent pour les accompagner dans la réouverture d’un secteur d’autocueillette de moules bleues de manière durable et sécuritaire. Les objectifs étaient d’identifier les enjeux associés à la cueillette de moules dans la documentation scientifique et de co-développer un arbre décisionnel permettant de guider la Première Nation dans l’éventuelle réouverture d’un secteur coquillier. Selon les résultats, la cueillette de moules peut être compromise par des enjeux de conservation de la ressource et/ou de salubrité. Pour que la cueillette soit durable et sécuritaire, il importe de valider que la ressource soit assez abondante et productive (biomasse, densité, taux de productivité) pour assurer la durabilité de la ressource malgré la cueillette, de vérifier la proximité de certaines installations humaines pour réduire les risques de contamination, puis de surveiller certains contaminants (coliformes fécaux, biotoxines marines) pour assurer la sécurité de la cueillette. Une fois ces étapes complétées, un secteur peut être ouvert à la cueillette en communiquant les règlements et les bonnes pratiques de l’autocueillette (taille minimale de cueillette, quotas quotidiens, etc.) pour contribuer à la durabilité de l’autocueillette. Lorsque l’autocueillette de moules bleues est pratiquée de manière durable et sécuritaire, elle permet de rapprocher les membres des communautés des ressources alimentaires du fleuve Saint-Laurent (province de Québec, Canada). Publication RestreintBiodiversity Ecosystem Functioning (BEF) approach to further understanding aquaculture-environment interactions(Blackwell Publishing, 2020-02-18) Lacoste, Élise; Archambault, Philippe; McKindsey, Christopher W.Coastal benthic ecosystems may be impacted by numerous human activities, including aquaculture, which continues to expand rapidly. Indeed, today aquaculture worldwide provides more biomass for human consumption than do wild fisheries. This rapid development raises questions about the interactions the practice has with the surrounding environment. In order to design strategies of sustainable ecosystem exploitation and marine spatial planning, a better understanding of coastal ecosystem functioning is needed so that tools to quantify impacts of human activities, including aquaculture, may be developed. To achieve this goal, some possible directions proposed are integrated studies leading to new concepts, model development based on these concepts and comparisons of various ecosystems on a global scale. This review draws on existing literature to (i) briefly summarize the major ecological interactions between off-bottom shellfish aquaculture and the environment, (ii) introduce research on the influence of benthic diversity on ecosystem functioning (BEF relationships) and (iii) propose a holistic approach to conduct aquaculture–environment studies using a BEF approach, highlighting the need for integrated studies that could offer insights and perspectives to guide future research efforts and improve the environmental management of aquaculture. Publication Accès libreReliance of deep-sea benthic macrofauna on ice-derived organic matter highlighted by multiple trophic markers during spring in Baffin Bay, Canadian Arctic(University of California Press, 2020-12-17) Yunda-Guarin, Gustavo; Archambault, Philippe; Brown, Thomas A.; Saint-Béat, Blanche; Michel, Loïc N.; Amiraux, Rémi; Nozais, ChristianBenthic organisms depend primarily on seasonal pulses of organic matter from primary producers. In the Arctic, declines in sea ice due to warming climate could lead to changes in this food supply with as yet unknown effects on benthic trophic dynamics. Benthic consumer diets and food web structure were studied in a seasonally ice-covered region of Baffin Bay during spring 2016 at stations ranging in depth from 199 to 2,111 m. We used a novel combination of highly branched isoprenoid (HBI) lipid biomarkers and stable isotope ratios (δ13C, δ15N) to better understand the relationship between the availability of carbon sources in spring on the seafloor and their assimilation and transfer within the benthic food web. Organic carbon from sea ice (sympagic carbon [SC]) was an important food source for benthic consumers. The lipid biomarker analyses revealed a high relative contribution of SC in sediments (mean SC% ± standard deviation [SD] = 86% ± 16.0, n = 17) and in benthic consumer tissues (mean SC% ± SD = 78% ± 19.7, n = 159). We also detected an effect of sea-ice concentration on the relative contribution of SC in sediment and in benthic consumers. Cluster analysis separated the study region into three different zones according to the relative proportions of SC assimilated by benthic macrofauna. We observed variation of the benthic food web between zones, with increases in the width of the ecological niche in zones with less sea-ice concentration, indicating greater diversity of carbon sources assimilated by consumers. In zones with greater sea-ice concentration, the higher availability of SC increased the ecological role that primary consumers play in driving a stronger transfer of nutrients to higher trophic levels. Based on our results, SC is an important energy source for Arctic deep-sea benthos in Baffin Bay, such that changes in spring sea-ice phenology could alter benthic food-web structure. Publication Accès libreOceans and human health : navigating changes on Canada’s coasts(Canadian Science Publishing, 2020-12-22) Archambault, Philippe; Batal, Malek; Kenny, Tiff-Annie; Chan, Hing Man; Little, Matthew; Cheun, William; Plante, Steve; Eddy, Tyler D.; Ayotte, Pierre; Ota, Yoshitaka; Pétrin-Desrosiers, Claudel; Poitras, Julien; Polanco, Fernando; Singh, Gerald; Lemire, MélanieOcean conditions can affect human health in a variety of ways that are often overlooked and unappreciated. Oceans adjacent to Canada are affected by many anthropogenic stressors, with implications for human health and well-being. Climate change further escalates these pressures and can expose coastal populations to unique health hazards and distressing conditions. However, current research efforts, education or training curriculums, and policies in Canada critically lack explicit consideration of these ocean–public health linkages. The objective of this paper is to present multiple disciplinary perspectives from academics and health practitioners to inform the development of future directions for research, capacity development, and policy and practice at the interface of oceans and human health in Canada. We synthesize major ocean and human health linkages in Canada, and identify climate-sensitive drivers of change, drawing attention to unique considerations in Canada. To support effective, sustained, and equitable collaborations at the nexus of oceans and human health, we recommend the need for progress in three critical areas: (i) holistic worldviews and perspectives, (ii) capacity development, and (iii) structural supports. Canada can play a key role in supporting the global community in addressing the health challenges of climate and ocean changes. Publication RestreintShell deformity as a marker for retrospective detection of a pathogenic unicellular alga, Coccomyxa sp., in mytilid mussels : a first case study and research agenda(Academic Press, 2019-12-16) Zuykov, Michael; Archambault, Philippe; Kolyuchkina, Galina; McKindsey, Christopher W.; Gosselin, Michel; Anderson, Julia; Spiers, Graeme; Schindler, MichaelAn L-shaped shell deformity (LSSD) on the posterior shell edge is known exclusively in wild mytilid mussels infected with photosynthetic Coccomyxa-like algae. LSSD forms due to the appearance of extra shell material; it only occurs if the mussel is heavily infected with the alga. Traditionally, observation of high amount of the green spots (algal colonies) on a large area of host soft tissues (most of the mantle and in adductor muscle) has been used to indicate a high infection rate. We examined 300 Mytilus spp. (100 small, 20–30 mm; 200 large, 40–60 mm) with a high degree of LSSD (parameter “d” > 5 mm) from the Lower St. Lawrence Estuary (Québec, Canada). Green spots were absent in two large mussels, and were only present along the mantle posterior edge in 14 large mussels; other individuals had high infection levels. Our observations suggest that some individuals could be in a state of remission, or, even more optimistically - mussels may be able to resist the pathogen. LSSD is the stable through-time marker for detection of mytilid mussels that are or were infected with Coccomyxa algae, and, thus, may provide information for the study of mussel immunity and control of alga distribution/migration in coastal waters worldwide. Publication RestreintPractical advice on monitoring of U and Pu with marine bivalve mollusks near the Fukushima Daiichi Nuclear Power Plan(Macmillan, 2020-01-29) Zuykov, Michael; Archambault, Philippe; Fowler, Scott W.; Spiers, Graeme; Schindler, MichaelFollowing the Fukushima Daiichi nuclear power plant accident in 2011, some marine radionuclide monitoring studies report a lack of evidence for contamination of Japanese coastal waters by U and Pu, or state that marine contamination by them was negligible. Nevertheless, Fukushima-derived U and Pu were reported as associated with Cs-rich microparticles (CsMPs) found in local soil, vegetation, and river/lake sediments. Over time, CsMPs can be transported to the sea via riverine runoff where actinides, as expected, will leach. We recommend establishing a long-term monitoring of U and Pu in the nearshore area of the Fukushima Prefecture using marine bivalve mollusks; shells, byssal threads and soft tissues should all be analyzed. Here, based on results from Th biosorption experiments, we propose that U and Pu could be present at concentrations several times higher in shells with a completely destroyed external shell layer (periostracum) than in shells with intact periostracum.