Seagrass meadows are among the most valuable coastal ecosystems on earth due to their structural and functional roles in the coastal environment. This study demonstrates remote sensing’s capacity to produce seagrass distribution maps on a regional scale. The seagrass coverage maps provided here describe and quantify for the first time the extent and the spatial distribution of seagrass meadows in Greek waters.

This information is needed for identifying priority conservation sites and to help coastal ecosystem managers and stakeholders to develop conservation strategies and design a resilient network of protected marine areas. The results were based on an object-based image analysis of 50 Landsat-8 satellite images. The time window of image acquisition was between June 2013 and July 2015. In total, the seagrass coverage in Greek waters was estimated at 2619 km2. The largest coverages of individual seagrass meadows were found around Lemnos Island (124 km2), Corfu Island (46 km2), and East Peloponnese (47 km2). The accuracy assessment of the detected areas was based on 62 Natura 2000 sites, for which habitat maps were available. The mean total accuracy for all 62 sites was estimated at 76.3%.

• For the first time, the seagrass beds’ distribution in Greek waters is mapped.
• The results were based on an object-based analysis of 50 Landsat-8 images.
• The seagrass coverage in Greek waters was estimated at 2619 km2.
• Results can be used to design a resilient network of protected marine areas.
• The produced maps are ideal for identifying priority conservation sites

The produced vector with the seagrass coverage can be downloaded from ZENODO database (DOI:10.5281/zenodo.1120338).

Reference: Konstantinos Topouzelis, Despina Makri, Nikolaos Stoupas, Apostolos Papakonstantinou, Stelios Katsanevakis, Seagrass mapping in Greek territorial waters using Landsat-8 satellite images, International Journal of Applied Earth Observation and Geoinformation, Volume 67, May 2018, Pages 98-113, https://doi.org/10.1016/j.jag.2017.12.013.