Towards a Comprehensive Functionality Assessment of Estuaries: First Approaches in San Vicente de la Barquera Estuary (Cantabria, Spain)

Estuaries are complex systems, usually composed by connected subsystems (mostly beaches, dunes, saltmarshes and the main channel), resulting in a complex geomorphology and ecology that makes difficult its study from a comprehensive perspective. In this sense, characterizing the functionality of an estuary is a key element to develop adequate management tools for these environments. Unfortunately, very few studies have focused on the connectivity among their elements, mostly overlooking the derived interactions inherent to them. As an example, San Vicente de la Barquera estuary (Cantabria, Spain) has been selected for this first approach. Considering an estuary as a heterogeneous and continuous system, where system components and processes are interconnected, the present work proposes as methodology the combination of different detailed maps to identify links between morphosedimentary systems and related EU habitats of community interest. The combination of these types of maps allows to drawn up a table of equivalences to relate morphosedimentary units and habitat characteristics from a geographical point of view. In a second phase of this approach, it will be identified physical processes related to morphological systems (i.e., river discharges, water mixing, tidal currents, dynamo-sedimentary models) and biological processes related to ecological systems (i.e., presence and variation of plant communities). Additionally, induced anthropogenic processes will be considered as driving forces acting directly on the previous ones. With the aim of evaluate the global dynamic of the estuary, a set of geo-ecological indicators are proposed to describe the processes and the connectivity established in between their subsystems. The main results of this preliminary study are expected to provide a comprehensive first vision of the estuary functioning, together with the design of a new methodology to improve the environmental characterization of estuaries.