"Coastal regions provide a wide range of resources and services, and thus represent an essential environment for human activities. However, coastal areas are rapidly degrading under the pressure of anthropogenic activities and climate change. Hence a correct management of the ecological resources of coastal regions is vital for a sustainable development. A correct management can not be achieved without understanding the mechanisms which regulate and control horizontal transport and cross-shelf exchanges. These processes play an important role in regulating the ecological and biogeochemical conditions of coastal regions. In recent years, Lagrangian techniques, like the Finite Size Lyapunov Exponent (FSLE) method, have become increasingly important for the analysis of horizontal mixing and transport in the oceans. FSLE can be used to identify Lagrangian Coherent Structures (LCSs) which provide direct information on transport and mixing patterns of a flow. The LACOSTE project will focus on the analysis of LCSs in the Gulf of Lion (GoL, Northwestern Mediterranean) in order to characterize the transport patterns from both numerical model results and altimetry derived velocity fields. A region-specific processing procedure for along-track altimetry measurements will be developed in order to obtain more accurate altimetry derived velocity fields in the GoL. LCS analysis will be integrated with two other new techniques: Self Organizing Maps (SOM) will be used to identify the dominant transport patterns and their temporal variability; the PHYSAT algorithm will be applied to remote sensed optical measurements to assess the ecological impact of the detected transport structures and to investigate the underlying physical-biogeochemical interactions. The LACOSTE project will allow to identify the areas most impacted by the dominant transport patterns, providing an essential contribution for the development of a sustainable management of the ecological resources of the GoL."