Remote Sensing Tools for Monitoring Marine Phanerogams: A Review of Sentinel and Landsat Applications

Seagrasses play a pivotal role in maintaining marine ecosystems, supporting biodiversity, and preventing sediment loss during storms. Their capacity for photosynthesis and growth is linked to light availability in the continental shelf waters. Satellite platforms such as Landsat (USGS) and Sentinel (ESA) provide accessible imagery for the monitoring of these submerged plants. This study employed the PRISMA methodology to conduct a systematic review of the literature, with the objective of identifying articles focused on these seagrasses and their detection via satellite imagery. The identified methodologies included the use of vegetation and water indices, which were validated through empirical observations, as well as supervised classification algorithms, such as Random Forest, Maximum Likelihood, and Support Vector Machine. These approaches were applied to Mediterranean and other coastal regions, revealing changes in seagrass cover due to anchor damage in tourist areas and trawling scars that resemble plough marks. Such tools are vital for informing management actions, such as the implementation of restrictions on anchoring and bottom trawling, in order to protect these vulnerable ecosystems. By enabling targeted interventions, this approach facilitates the preservation of seagrass meadows, which are also critical for carbon sequestration and the sustainability of marine habitats.