The general objective of the Si-WEBS network is to integrate the Si biogeochemical cycle into a human perspective, by evaluating the worldwide impacts of natural and anthropogenic perturbations of the coastal Si cycle onto a) the ecology of coastal ecosystems, b) the biogeochemistry of the global Si and C cycles, and c) the socio-economics of the coastal zone. The importance of Si for both coastal ecosystem health and the C cycle arises from the unique requirement of diatoms for this nutrient. Diatoms are unicellular algae that play a key role in the export of carbon, towards higher trophic levels (they form the basis of high quality food chains) and the ocean interior (and thus in the C biological pump). To reach these general objectives, Si-WEBS will proceed in 4 steps:
1) improve our fundamental knowledge of the coupling between the Si and C cycles in rivers, coastal zones and open oceans, first separately, then during their interactions;
2) build quantitative modeling tools to describe Si transformations along the land-ocean continuum;
3) use these modeling tools to evaluate ecological, biogeochemical and socio-economical consequences, of natural and anthropogenic watershed perturbations on the coastal zone;
4) provide innovative tools that will include Si as a key parameter for coastal ecosystem management in a sustainable perspective (a coupled river/coastal zone model to simulate the effects of various watershed management policies, early warning indicators) to policy makers. Eight teams have been brought together to carry out this strongly interdisciplinary research. This unique combination of scientists with complementary expertise in various fields (ecology, bio-geochemistry, global modeling, socio-economics), with various skills (experimentalist, modeler, data manager), and acting in various environments (from the watershed to the open ocean) shall make this network a success, both in terms of scientific achievements and training of young researchers.