Panayotidis 2022. Seagrass Meadows in the Greek Seas: Presence, Abundance and Spatial Distribution

Panayotidis, Panayiotis, Vasillis Papathanasiou, Vasileios Gerakaris, Elias Fakiris, Sotiris Orfanidis, Georgios Papatheodorou, Maria Kosmidou, Nikos Georgiou, Vivi Drakopoulou, and Valia Loukaidi. 2022. “Seagrass Meadows in the Greek Seas: Presence, Abundance and Spatial Distribution.” Botanica Marina. doi: 10.1515/bot-2022-0011.

Combined use of optical (satellite imagery) and acoustic (sidescan sonar) remote sensing techniques, as well as in situ methodologies (visual census; SCUBA diving, Towed Underwater Cameras, and Remotely Operated Vehicles) was employed to map the spatial distribution of seagrass habitats in the coastal waters of the Greek territory. Seagrass meadows were recorded over approximately 70% of the Greek coastline (Eastern Ionian, Aegean and Levantine Seas), and their surface area exceeded 2749.07 km2. Posidonia oceanica is clearly the dominant seagrass species in Greek Seas, covering the vast majority of seabed at depths between the shoreline and 25–30 m (or deeper in insular areas), followed by the species Cymodocea nodosa , Zostera noltei , and Halophila stipulacea , that are not widely distributed but are locally abundant in specific areas. Habitat suitability in terms of the of the seabed that is available for the growth of seagrass meadows (i.e., the spatial extent of coastal areas between the shoreline and the isobath of 20 m) and the seawater clarity conditions are highlighted as the critical factors for the formation of well-structured and extensive meadows. The results of this study are of great importance and usefulness for the effective management and conservation of valuable marine ecosystems and are given in the form of an openly accessible shapefile.