The role of Earth Observation in supporting holistic coastal lagoon management

Coastal lagoons are complex and dynamic transitional ecosystems that form an interface between freshwater and marine waters, resource rich and heavily influenced by human activities. Management of lagoon systems is not only complex because of the wide range of co-located activities and interests (e.g., economic vs. conservation), but also because the natural status of lagoons is affected by anthropogenic pressures (e.g., pollution) and climate change impacts (e.g., sea level). In addition, they are systems with great spatial and temporal variability under naturally fluctuating conditions, making them inherently ever-changing systems, and meaning that they exist within a naturally evolving life cycle of bio-physical change. Providing a framework that informs coastal lagoon management should address the challenges of (i) monitoring and understanding processes of global environmental change; (ii) predicting risks, understanding and mitigating consequences for current and future extractive and non-extractive resource utilisation; and (iii) forecasting the bio-physical evolution of coastal lagoon systems under both natural and anthropogenically altered conditions. Such a framework requires data that are spatially and temporally explicit, and measure, either directly or via a proxy, a set of indices and indicators that reflect the link and association between the biophysical components of lagoon systems with the resources and ecosystem services that underpin anthropogenic exploitation. Research and technological development play a key role in this. This White Paper, based on expert knowledge, aims to give a broad vision on the state of knowledge of coastal lagoons and present the potential and limitations of Earth Observation (EO) technologies to support a holistic management approach. Finally, it provides actionable recommendations to address the challenges of applying EO in coastal lagoon systems, including enhancing interdisciplinary collaboration, improving algorithm development and validation, promoting global initiatives, and fostering capacity-building in resource-limited regions.