Inland and coastal water ecosystems provide essential services to humans (i.e. drinking water, fisheries). As important and biodiverse habitats they play a crucial role in global carbon and water cycles. Water is essential for the blue economy by facilitating diverse activities in industry, commerce, and recreation. Despite the importance of these ecosystems, they are severely under threat. Consequences of anthropogenic activities and global environmental change (e.g. water overexploitation, pollution, weather extremes, water level changes) particularly affect water oxygen regimes, columnar stratification, productivity and food chains, and the health of aquatic life. The increasing vulnerability of aquatic ecosystems severely compromises their capacity and increases the risk to provide ecosystem services.

Detailed understanding and knowledge of globally distributed and highly dynamic aquatic ecosystems are urgently needed to implement sustainable protection and management of these ecosystems. Systematic observations are essential for this purpose and must include detailed in situ monitoring together with satellite remote sensing for harmonized global water information. While a multitude of available remote sensing missions particularly focuses on ocean biology and biogeochemistry and terrestrial environments, satellite missions specifically designed to study critical coastal and inland aquatic ecosystems at a global scale are non-existent. This observational gap is determined by the high dynamic and optical complexity of water ecosystems, combined with technological challenges to optimize the relevant radiometric, spatial, spectral, and temporal sampling.

The object of this Working Group is to define requirements and main components of a future satellite mission that will dynamically measure coastal and inland aquatic ecosystems and allow advancing science of these ecosystems. The setting provided by ISSI is unique to gathering the required diverse expertise and to discussing relevant questions including:

(i) the distribution and dynamic of phytoplankton stocks, diversity, productivity, and carbon fluxes in coastal and inland aquatic ecosystems

(ii) the state and expected trajectory of water quality on Earth and which types and concentrations of contaminants exist in coastal and inland waters and their aggregation zones

(iii) the requirements for a water mission to best serving aquatic science and contribute to addressing upcoming societal challenges, including biodiversity loss, water scarcity, and carbon and water cycling.

Complementing the scientific activities and achievements of earlier ISSI-WG’s addressing the scientific aspects of physical Oceanography also in the coastal zone, this WG would specifically address biological and biochemical conditions of coastal and inland aquatic ecosystems.