Connectivity between river catchment and coastal seas - Part of the Water Quality Summit Series

Connectivity between river catchment and coastal seas: Case study - The River Tamar and Western English Channel

Observations of the River Tamar, its estuary and adjacent coastal waters provide a powerful example of source-to-sea connectivity, linking land management and climate change to the health of coastal ecosystems. Long-term research by Plymouth Marine Laboratory and partners has shown how rainfall, river discharge and agricultural activities drive nutrient and carbon transport from the catchment into the Tamar estuary, Plymouth Sound and the western English Channel, while climate-driven changes in rainfall intensity and hydrology are expected to alter these land-sea fluxes. Combining in situ observations with satellite-derived optical water type detection and high-resolution computer models now allows us to track estuarine influence and water quality from space, revealing that Tamar waters can affect coastal conditions up to 10 km offshore. This talk explores how catchment processes and a changing environment influence coastal seas, and how emerging monitoring technologies are transforming our understanding of land-sea connections.

This is part of the 2026 Water Quality Summit hosted by Devon County Council