Axis 3: Influence of contaminants on organisms of coastal environments
In a context of constant anthropisation, marine organisms are exposed to a growing diversity of elements or molecules (e.g. metals, pesticides, PAHs, CO2, etc.), whose concentrations exceed the levels considered to be natural (Goldberg, 1995). Most of these contaminants are bioavailable; they penetrate biological tissues, accumulate and can then induce serious disturbances at the molecular, cellular or systemic level. They affect essential physiological functions such as immunity, locomotion or reproduction, and have ecological consequences on the condition, growth, survival and fitness of individuals and on the maintenance of populations.
Axis 1 of the AMARE team focuses on studying the influence of contaminants on marine organisms, while seeking to decipher the processes involved at three levels:
- the processes of bioaccumulation, through the study of:
– the sources of contaminants
– the pathways of entry into biological tissues (prey, dissolved forms, sediment, maternal transfer)
– the processes of detoxification (metabolisation, storage, elimination)
- the effects of contaminants, alone (controlled conditions) or in mixtures (sampling on polluted sites), on individual capacities.
– molecular response: e.g. functional genomics, enzymatic activities.
– systemic response: e.g. cardiac performance, endocrine system.
– eco-physiological response: e.g. locomotion, metabolism, immune capacity.
– ecological response (individual, population and community): e.g. growth, reproductive success, behaviour, distribution, ecological niche.
– the impacts of contaminants on populations and communities, by searching for correlations between the contaminant levels measured in different populations and demographic parameters, e.g. growth, survival, individual and population reproductive success
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These questions are constantly placed in an environmental context, thus taking into account the importance of abiotic factors (e.g. temperature), biotic factors (e.g. ontogenetic stage) and ecological factors (e.g. spatio-temporal variations, changes in the structure and functioning of the ecosystem’s trophic web).
The purpose of this work is multiple and aims to achieve:
- the definition of sensitivity thresholds of organisms to contaminants
- the measurement of energetic and demographic parameters under the influence of contaminants
- estimating the role of organisms in the transfer and dispersal of contaminants within ecosystems.
- assessing the impact of contaminants on the population dynamics of marine organisms and on the structure of communities.
- targeting the importance of bio-indicator species for the contamination status of the environment and its spatio-temporal variations.
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