Personne : Archambault, Philippe
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Université Laval. Département de biologie
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- PublicationAccès 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.
- PublicationAccès 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.
- PublicationRestreintShell 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.
- PublicationRestreintAssistive robotic device : evaluation of intelligent algorithms(RESNA, 2018-07-01) Archambault, Philippe; Lettre, Josiane; Routhier, François; Campeau-Lecours, Alexandre; Lebrasseur, AudreyAssistive robotic devices can be used to help people with upper body disabilities gaining more autonomy in their daily life. Although basic motions such as positioning and orienting an assistive robot gripper in space allow performance of many tasks, it might be time consuming and tedious to perform more complex tasks. To overcome these difficulties, improvements can be implemented at different levels, such as mechanical design, control interfaces and intelligent control algorithms. In order to guide the design of solutions, it is important to assess the impact and potential of different innovations. This paper thus presents the evaluation of three intelligent algorithms aiming to improve the performance of the JACO robotic arm (Kinova Robotics). The evaluated algorithms are ‘preset position’, ‘fluidity filter’ and ‘drinking mode’. The algorithm evaluation was performed with 14 motorized wheelchair’s users and showed a statistically significant improvement of the robot’s performance.
- PublicationRestreintBiodiversity 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.
- PublicationAccès 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 (d13C, d15N) 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] ¼ 86% + 16.0, n ¼ 17) and in benthic consumer tissues (mean SC% + SD ¼ 78% + 19.7, n ¼ 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 foodweb structure.
- PublicationRestreintPractical 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.