6 - Evolution of marine habitats and adaptation of populations
Coordinators : Cédric BACHER (Ifremer/DYNECO), Christine PAILLARD (IUEM/LEMAR)
Laboratoire des sciences de l'environnement marin), UBO, CNRS, IRD(
In the frame of global changes, major disturbances of marine ecosystems result in individual responses (behaviour, physiology, evolution, ontogeny) to environmental stress which therefore affect biological traits, adaptive capacity of living organisms and spatio-temporal dynamics of populations. At a larger scale, physical habitats, distributions of populations and structure of communities are also modified by environmental changes (e.g. temperature, contamination by chemicals, eutrophication, hydrodynamics and morphodynamics) and biotic interactions (e.g. predation, competition, symbiosis and parasitism). A step forward would consist in fully integrating ecophysiology, evolutionary, macroecology and ecological niche approaches to address issues of biodiversity conservation. This is why the coupling between population dynamics, models of bioclimatic envelopes, georeferenced environmental data and evolutionary biology is now emerging in terrestrial ecology. Application of such concepts and tools to marine ecology is certainly innovative and would improve existing methods and models which have shown their limitations.
We propose to adapt this emerging methodological framework to analyse and simulate the changes of marine biodiversity due to environmental and anthropogenic pressures. For this purpose, specific objectives have been identified:
- Assess adaptive and physiological responses through (i) the reconstruction of past evolution by using sclerochronology, sclerochemistry, molecular and physiological proxies, (ii) the quantification of adaptive capacity and evolution by combining experimental approaches, molecular biology and quantitative genetics,
- Characterise habitats and biological communities through analysing and identifying structuring factors (e.g. morphosedimentary and hydrodynamics forcing, engineering invasive species, implantation of marine renewable energy technologies, etc.), mapping habitats mosaics and studying species assemblages in different types of environment,
- Formulate and couple interactions to simulate (i) physiological responses, (ii) changes of biotopes, distributions and ecological niches for target species, (iii) benthic and pelagic population dynamics, (iv) distribution of communities,
- Reconstruct past changes, test hypotheses and simulate scenarios of future changes by integrating models at different scales (organism, population, and habitat).
By analysing and coupling marine habitats, ecosystem functioning and adaptive responses, we will more precisely address the following questions:
- At what level and how the interactions between physiological plasticity, adaptation by populations and environmental changes must be formalized?
- What are the consequences of such interactions on ecological niches, and at what scales can they be observed?
- Which mathematical models must be developed to simulate the spatio-temporal evolution of habitats, species and communities?
- What are the effects of conservation and restoration strategies on these biological levels?
The Labex MER partners are recognised for their skills in habitat mapping, database management, operational modelling, coastal monitoring and use of functional approaches in marine biology (ecophysiology, biotic interactions, sclerochronology). The project also relies upon existing National and European initiatives on responses of fishes and bivalves to environmental stressors, use of biological archives and paleo-oceanography proxies to reconstruct past environment. LabexMER will provide the necessary incentive to build synergies and address the challenges related to multiple scales interactions and complexity (e.g. short term/long term, individuals/population/ecosystem, and mosaics of habitats).
Major outcomes are expected at a scientific level. Results will provide a better understanding of adaptive capacity of organisms, population dynamics and interactions between habitats and communities organisation. Our multidisciplinary approach will develop and validate analytical techniques, yield novel mathematical models capable to handle ecosystem complexity and improve the predictions of ecosystem changes. Our findings will also contribute to the improvement of scientific expertise and benefit to public policies regarding the conservation of marine area, the assessment of marine services and the ecological status of coastal zones.