the oceans are a major source of biodiversity and food. The preservation of the quality of the foodchain, as well as of life underwater in general is a primary concern for society. However, observing water media routinely is a complex task that remote sensing technology empowered by AI can unlock. In this talk, I will present some research avenues, where the use of remote sensing can help monitoring marine ecosystem, both above - via the monitoring of floating plastic debris - and under the water surface - via 3D reconstruction and mapping of coral reefs.