Contaminants, future and answers

, par Vidal Ayouba Isabelle

Representatives : Christophe Leboulanger (IRD) and Jehan-Hervé Lignot (UM2)

BACKGROUND

Contaminants from natural and / or anthropogenic origin potentially toxic to organisms
 constitute a pressure that could permanently affect marine ecosystems. The presence and effects of these contaminants cause a change in the environment, imposing adjustments and evolutions for micro- and macro-organisms developing inside this environment. To understand and anticipate these processes requires (i) to characterize the future and impact of contaminants in organisms and food webs and their bioavailability in abiotic compartments, (ii) to evaluate the resistance and adaptation capacities of the organisms, their responses and evolution at various organization levels (from the gene to the community).
Future, impact and adaptation will be addressed by considering major scientific issues : (1) the multiexhibition of organisms and the cocktail effect, (2) the consideration of a wide range of compounds, from algal toxins to conventional and emerging chemical contaminants, (3) interactions with other stress factors.

GOALS

  • To assess the levels and sources of contamination of temperate and tropical marine environments

  • To describe the abiotic (degradation, adsorption / desorption ...) and biotic future of contaminants
• (bioavailability, bioaccumulation, metabolism), from microbial organisms to marine predators,

  • To assess the effects of contaminants on organisms in situ and in vitro by searching for biomarkers of exposure,

  • To determine the concentrations’ threshold for which the effects will be felt at increasing complexity levels, from the cell and its genome to communities,
  • 
To develop an integrated approach, taking into account the impact and future of pollutants and other stress factors (salinity, temperature, partial pressure of CO2 ...).

OBJECTS AND MAIN AREAS OF STUDY

  • Geographic areas : North and South Mediterranean, West Africa, Western Indian Ocean, Southeast Asia,

  • Biological models : free and symbiotic microorganisms, primary producers, shellfish, mollusks, fish ; multilevel approaches

  • Contaminants : persistent organic pollutants, hydrophilic organic, metals, algal toxins, endocrine disruptors, emerging pollutants, nanoparticles, sprays.

APPROACHES

  • Data (water, sediment, organisms, tissues, organs) : acquisition (1) through in situ punctual or permanent observations (observation networks ROCCH, RINBIO, RSL, RESOMAR, REPHY, etc.) and (2) with experimental conditions (controlled cultures, farms, micro-mesocosms).

  • Measurement and proxies : concentration levels in the biotic and abiotic compartments ; effects thresholds (on metabolic activities, population dynamics, interactions within communities ...)

  • Methods and tools : approaches combining analytical chemistry (including passive samplers), physiology, histology, proteomics, lipidomics, and molecular biology (DNA and RNA).

  • Modeling : dose-effect relationships (Hill’s model, toxic interaction models ...) trophic transfer process ; coupled with ecological models (population dynamics, communities structure) and biogeochemical.


LES PROJETS




MARBEC MARine Biodiversity, Exploitation and Conservation, is a research unit which includes the staff of 4 organizations: IRD, IFREMER, UM and CNRS. Its objective is the study of marine biodiversity in lagoon coastal and offshore ecosystems, at different integration levels, molecular, individual, population and community aspects and the way humans use this biodiversity.