This dataset shows the modelled spatial distribution of Posidonia oceanica seagrass in the Mediterranean Sea. Posidonia oceanica is endemic to the Mediterranean Sea, where it is the dominant seagrass. It is found in sandy and rocky areas down to depths of about 45 m. P. oceanica is a protected species under European and international law, as well as several national legislations.

The model was built based on an (observed) P. oceanica occurrence dataset extracted from a Mediterranean-wide database curated by Andrea Belluscio (University of Rome, Italy) - see Telesca et al. (2015) for further details. A Random Forest (i.e. a very effective Machine Learning technique) was trained on data from regions where information was available and then used to predict the probability of occurrence of P. oceanica where needed. Please refer to Scardi et al. (2013) for full details of the methodology used. The maps show interim model outputs, which are likely to be improved with additional species occurrence data.

The data layers may be used (1) to guide cost-effective future survey efforts towards poorly sampled areas that are more likely to support these two habitats, (2) to inform marine spatial planning (including conservation planning), (3) to inform marine policy development, and (4) for initial screening as part of an environmental impact assessment. The data layer should not be used for spatial measures targeting fisheries, without prior groundtruthing.

Credits: "Giannoulaki M, Belluscio A, Colloca F, Fraschetti S, Scardi M, Smith C, Panayotidis P, Valavanis V, Spedicato MT (Eds.) (2013). Mediterranean Sensitive Habitats (MEDISEH), final project report. DG MARE Specific Contract SI2.600741. Heraklion (Greece): Hellenic Centre for Marine Research. 557 p. URL: http://mareaproject.net/download/71 ; http://www.emodnetseabedhabitats.eu/default.aspx?page=1974","Telesca L, Belluscio A, Criscoli A, Ardizzone G, Apostolaki ET, Fraschetti S, Gristina M, Knittweis L, Martin CS, Pergent G, Alagna A, Badalamenti F, Garofalo G, Gerakaris V, Pace ML, Pergent-Martini C, Salomidi M. Seagrass meadows (Posidonia oceanica) distribution and trajectories of change. Scientific Reports 5: 12505. URL: http://www.nature.com/srep/2015/150728/srep12505/full/srep12505.html","Scardi M, Martin CS, Valavanis V, Fraschetti S, Belluscio A, Gristina M, Salomidi M, Punzo E, Panayotidis P, Giannoulaki M (2013). Task 1.3. Modelling of protected habitats using predictor variables. In: Mediterranean Sensitive Habitats (MEDISEH), final project report (Eds. M Giannoulaki, A Belluscio, F Colloca, S Fraschetti, M Scardi, C Smith, P Panayotidis, V Valavanis, MT Spedicato). DG - MARE, specific contract SI2.600741. Heraklion (Greece): Hellenic Centre for Marine Research. 557pp."]