Th remote sensing of Seagrass population is possible by acquiring high and medium resolution satellite images (such as Geo-eye and Sentinel-2 respectively) for Digital image processing using their respective spectral signatures to detect and classify different habitats, and estimates the accuracy of seagrass mapping.
The quality of Sentinel-2 and Geo-eye images are useful for seagrass mapping, the ability of each band in detection and discrimination of different habitats and estimates the accuracy of seagrass mapping.
For further readings, check the attached articles. You could find them useful.
I think its important to consider the temporal and spatial scale of the study and also the exact aim - as acquiring satellite data can be expensive and/or unsuitable for other reasons, there has been a number of papers on the application of low-cost drones to monitor marine habitats with regards to seagrasses. I've attached some, maybe this helps too!
A bit of context around the spatial and maybe temporal resolution of your envisaged seagrass mapping would be very helpful here, but perhaps you could find helpful information towards your endeavours in the two attached papers. These describe seagrass mapping using open 10-m Sentinel-2 satellite data in single and multi-temporal approaches for both local and national scale efforts.
Let me know if you need any further help in your endeavours.