DOI: 10.5061/dryad.nvx0k6f0c
title: Identifying gaps in the protection of Mediterranean seagrass habitats using network-based prioritization

description: Aim Seagrass meadows represent a key marine ecosystem owing to the
 significant biodiversity they host. Protection actions are often
 implemented without considering connectivity between habitats. In this
 paper, we map and prioritize Mediterranean seagrass habitats (Posidonia
 oceanica and Cymodocea nodosa) based on their high potential as
 sources/retention of dispersal propagules or as stepping-stones. We use
 this information to identify gaps in the protection of highly ranked
 habitats. Location Mediterranean Sea Methods We use highly
 spatial resolved marine environmental predictors and species distribution
 models (SDMs) to map the seagrasses distribution. Then, we use a
 network-based approach to rank all predicted seagrass habitats based on
 their contribution to the landscape in terms of patch area (dPCintra
 index), potential as source/retention of propagules (dPCflux index), and
 stepping-stone (dPCconnector index). Finally, by overlaying our ranking
 with the spatial distribution of Marine Protected Areas (MPAs), we
 identify potential gaps in the protection of important seagrass habitats
 across the Mediterranean and its basins.  Results Most
 of the identified seagrasses habitat patches are not included in MPAs,
 with a protection coverage exceeding half of the identified patches only
 in the northwestern Mediterranean. Relatively few patches contribute
 disproportionately to connectivity. Top ranked habitat patches are
 systematically excluded from the existing MPAs network, both at the
 Mediterranean scale and for most basins, with largest gaps for the
 source/sink role in the Aegean and Ionian Sea, and largest gaps for the
 stepping-stone role in the Adriatic, Ionian, and Tyrrenean Sea. Main
 conclusions Our results suggest that the current MPAs network fails to
 protect highly relevant seagrasses habitats in the large majority of the
 Mediterranean basins. However, this gap could be filled by a few
 well-placed MPAs. Overall, we provide novel insights for the
 identification of key habitats and planning novel coastal MPAs in the
 region.
description: Data generated by using highly spatial resolved marine
 environmental predictors and species distribution models (SDMs) to map the
 seagrasses (P. oceanica and C. nodosa) distribution for the Mediterranean
 sea. Connectivity indices for habitat patches calculated with a
 network-based approach (CONEFOR): to describe a) patches contribution to
 the landscape in terms of patch area (dPCintra index); b) potential as
 source/retention of propagules (dPCflux index); and c) stepping-stone role
 (dPCconnector index).
description: # Connectivity indices for mediterranean seagrass habitats
 [https://doi.org/10.5061/dryad.nvx0k6f0c](https://doi.org/10.5061/dryad.nvx0k6f0c) Data generated by using highly spatial resolved marine environmental predictors and species distribution models (SDMs) to map the seagrasses (P. oceanica and C. nodosa) distribution for the mediterranean sea. Connectivity indices for habitat patches calculated with a network-based approach (CONEFOR): to describe a) patches contribution to the landscape in terms of patch area (dPCintra index); b) potential as source/retention of propagules (dPCflux index); and c) stepping-stone role (dPCconnector index). ## Description of the data and file structure Data provided in .csv format. Column names: * FID: identification code for the geographic point * lon_WGS84: point longitude in WGS84 reference system * lat_WGS84: point latitude in WGS84 reference system * patch_ID: ID of the habitat patch the point belongs to * mpa_type: numeric code of the Marine Protected Area (MPA) the point belongs to. 0: point not included in MPA; 1: point included in international MPA; 2: point included in regional MPA; 3: point included in national MPA * basin: mediterranean basin the point belongs to. alb: Alborean Sea; nwm: north-west Mediterranean; swm: south-west Mediterranean; tyr: Tyrrhenian Sea; ion: Ionian sea; adr: Adriatic sea; arg: Aegean sea; lev: Levantine sea * dPCintra: connectivity index; see doi: 10.1111/j.1600-0587.2009.05760.x * dPCflux: connectivity index; see doi: 10.1111/j.1600-0587.2009.05760.x * dPCconnector: connectivity index; see doi: 10.1111/j.1600-0587.2009.05760.x