Seagrass Meadows in The Greek Seas
|Author(s)||Panayotidis Panayiotis1, Papathanasiou Vasillis2, Gerakaris Vasilis1, Fakiris Elias3, Orfanidis Sotiris2, Papatheodorou Georgios3, Kosmidou Maria2, Georgiou Nikos3, Drakopoulou Paraskevi1, Loukaidi Vasiliki1|
|Affiliation(s)||1 : Hellenic Centre for Marine Research (HCMR), Institute of Oceanography
2 : Fisheries Research Institute (FRI), Hellenic Agricultural Organization-DEMETER
3 : Laboratory of Marine Geology and Physical Oceanography (Oceanus-Lab), Geology Department, University of Patras
|Keyword(s)||seagrass, posidonia oceanica, wide-scale mapping, satellite, sidescan sonar, Eastern Mediterranean Sea|
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 Hellenic territory. Seagrass meadows were recorded at approximately 70% of the Hellenic coastline (Eastern Ionian, Aegean and Levantine Seas), and their surface area exceeded 2,673.1 km2. Posidonia oceanica is -by far- the dominant seagrass species of the Hellenic 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, which, however, presenting local presence and limited areal extent. Habitat suitability in terms of the seabed spatial extent that is available for the growth of seagrass meadows (i.e., the spatial extent of coastal areas between the shoreline and the isobath of 20m) 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.