Food web Integration: lessons learned from practical case studies Food-web models and political decision: what could be learned from simulations of cumulated impacts on the Baie of Seine food-web properties?
Résumé
The Baie of Seine is a highly impacted ecosystem of the English Channel subjected to fishing, harbour building, dredging, dredged material disposal, pollution etc. It is also highly sensitive to climate change and associated species distribution changes. Moreover, 3 projects of offshore wind-farm building are under negotiation in this ecosystem. Several of those pressures have been studied by food-web modellers, looking at functional and holistic properties derived from the Ecological Network Analysis (ENA) indices (see poster Tecchio et al. and Raoux et al.) like connectance, redundancy, trophic efficiency, mean trophic level, recycling or omnivory. These studies are based on different methods where network interactions are quantified or not (qualitative modelling), static or dynamic, statistic (allowing uncertainty estimation) or not. These different models were analysed in order to answer the question: what would be useful, in these ecological studies in the decision and policy-making process? This analysis is based on the conclusions about the understanding of effects of human pressures on the complexity of the functioning of ecosystems and their integration into social-ecological system, with a special interest in interactions of scales, uncertainty estimation, possible use of scenarios and indirect interactions between decisions, through ecosystem changes.