Distribution of coralligenous formations in the Mediterranean Sea.

<p>Red cells indicate planning units with the presence of coralligenous formations. Information on the spatial distribution of coralligenous formations was extracted from various sources which are provided as a supplementary material.</p

Distribution of marine caves in the Mediterranean Sea.

<p>Different colours indicate the variation in cave number per planning unit, warmer colours illustrating planning units with higher number of caves. Information on the spatial distribution of marine caves was extracted from various sources which are provided as a supplementary material.</p

Distribution of opportunity cost for commercial fishing, non-commercial fishing and aquaculture across the Mediterranean Sea.

<p>Darker shades indicate areas with higher opportunity cost (in Euros).</p

Spatial overlap between the identified priority conservation areas and existing MPAs in each ecoregion.

<p>Different colours have been used to illustrate the percentage of planning units for the A. Alboran Sea, B. Algero-Provencal Basin, C. Tunisian Plateau, D. Levantine Sea, E. Tyrrhenian Sea, F. Adriatic Sea, G. Ionian Sea, and H. Aegean Sea, that a) did not contain an MPA but was identified as priority area (red), b) contained an MPA and was identified as priority area (orange), c) did not contain an MPA and was not identified as a priority area (green) and d) contained an MPA but was not identified as priority area (blue).</p

Percentage of area cover and opportunity cost when planning at different spatial scales.

<p>Percentage area cover and percentage opportunity cost of planning units required in each ecoregion of the Mediterranean Sea for scenarios a and b (scenario a: selection of priority areas across the whole Mediterranean Sea, and b: selection of priority areas for each ecoregion separately).</p

Distribution of <i>Posidonia oceanica</i> meadows in the Mediterranean Sea.

<p>Green cells indicate planning units with the presence of <i>P. oceanica</i>. Information on the spatial distribution of <i>P. oceanica</i> was extracted from various sources which are provided as a supplementary material.</p

Map of the study area divided into 8 ecoregions, <i>sensu</i> Notarbartolo di Sciara and Agardy (2010).

<p>The study area comprises the entire Mediterranean Sea, excluding areas deeper than 1000</p

Distribution of habitats across ecoregions of the Mediterranean Sea.

<p>We calculated (i) the number of planning units in each ecoregion (N); (ii) the number of planning units with presence of each habitat in each ecoregion (<i>P. oceanica</i>: Ns, coralligenous: Nc, marine caves: Nmc), (iii) the percentage of Ns, Nc, Nmc across the Mediterranean Sea (N %), (iv) the percentage of Ns, Nc, Nmc across each ecoregion (Nr %); (v) the number of caves in each ecoregion (Nc) and (vi) the percentage of marine caves of each ecoregion across the Mediterranean Sea (Nc %).</p

Unpublished Mediterranean records of marine alien and cryptogenic species

Good datasets of geo-referenced records of alien species are a prerequisite for assessing the spatio-temporal dynamics of biological invasions, their invasive potential, and the magnitude of their impacts. However, with the exception of first records on a country level or wider regions, observations of species presence tend to remain unpublished, buried in scattered repositories or in the personal databases of experts. Through an initiative to collect, harmonize and make such unpublished data for marine alien and cryptogenic species in the Mediterranean Sea available, a large dataset comprising 5376 records was created. It includes records of 239 alien or cryptogenic taxa (192 Animalia, 24 Plantae, 23 Chromista) from 19 countries surrounding the Mediterranean Sea. In terms of records, the most reported Phyla in descending order were Chordata, Mollusca, Chlorophyta, Arthropoda, and Rhodophyta. The most recorded species was Caulerpa cylindracea, followed by Siganus luridus, Magallana sp. (cf. gigas or angulata) and Pterois miles. The dataset includes records from 1972 to 2020, with the highest number of records observed in 2018. Among the records of the dataset, Dictyota acutiloba is a first record for the Mediterranean Sea. Nine first country records are also included: the alga Caulerpa taxifolia var. distichophylla, the cube boxfish Ostracion cubicus, and the cleaner shrimp Urocaridella pulchella from Israel; the sponge Paraleucilla magna from Libya and Slovenia; the lumpfish Cyclopterus lumpus from Cyprus; the bryozoan Celleporaria vermiformis and the polychaetes Prionospio depauperata and Notomastus aberans from Malta.</p