Table 1. Main characteristics of the six existing conservation plans in the Mediterranean Sea (additional information in SOM).

Name of Initiative	Type of Organisation	Motivation	Approach1	Criteria	Planning Tool	Reference	Map viewable in Figure	% included (of tot Med Sea area)
National initiatives/ Present MPAs	Governmental; aggregation of national initiatives	Legally binding	mainly biodiversity driven; in some indirect socioeconomic and threat considerations; most have been selected opportunistically	various criteria	Mainly expert judgement	Abdulla et al. 2008, Abdulla et al. 2009 (first MPA was established in 1963)	1. a	3.8%
EU/Nationally designated areas (CDDA)	Governmental; aggregation of EU member-states initiatives	Legally binding	mainly biodiversity driven	Biodiversity: Designation types used with the intention to protect species, habitats and landscapes; statutes under sectorial, legislative and administrative acts providing adequate protection relevant to species and habitat conservation; private statute providing durable protection for species and habitats	Expert judgement	http://www.eea.europa.eu/data-and-maps/data/nationally-designated-areas-national-cdda-3 (inventory started in 1985)	1. b	1.3%
UNESCO/Marine World Heritage Sites	Inter-governmental Convention	Legally binding	Cultural and Biodiversity driven	Biodiversity: important biological and ecological processes for the evolution of species, important habitats for high biodiversity and for threatened species. Geological: significant geological processes and geomorphic features. Cultural and aesthetic uniqueness	Expert judgement	http://whc.unesco.org/en/list (first marine world heritage site listed in 1983)	1. c	N/A
Barcelona Convention SPA-BD protocol/Specially protected areas of Mediterranean Importance (SPAMIs)	Inter-governmental treaty	Legally binding	Biodiversity driven; consideration of scientific, aesthetic, cultural or educational importance	Biodiversity (species distribution and habitats): 5 main criteria: 1. Uniqueness; 2. Natural representativeness; 3. Diversity; 4. Naturalness; 5. Presence of habitats that are critical to endangered, threatened or endemic species; and Cultural representativeness	Expert judgement, political decision (nomination of sites by the party/parties concerned)	SPA/BD 1995	1. c	N/A
EU/Natura 2000 network	Inter-governmental body (EU)	Legally binding	Biodiversity driven	Biodiversity (species distribution and habitats): 9 broad habitat types and 10 priority species (relevant for the Mediterranean); criteria: representativeness, % coverage, size, degree of conservation, degree of isolation, evaluation of the overall value of the site for priority species and habitats	Expert judgement	Habitats Directive (EC, 1992); Birds Directive (EC, 2009); Process initiated in 1996 – on-going expansion of the network	1. d	1.3%
Ramsar, Convention on Wetlands	Inter-governmental treaty	Legally binding	Biodiversity driven	Biodiversity (species distribution and habitats): 9 criteria for the importance of the included habitats, bird and fish populations, endangered species and communities, and their role as spawning/nursery areas, feeding grounds, or migration paths (see details in Suppl. 1)	Expert judgement, quantitative data and analysis	Ramsar Convention Secretariat, 2010 (strategic framework and guidelines first adopted in 1999)	1. e	0.1%

¹Biodiversity driven: The priority areas were selected considering biophysical data only; Threats: The priority areas were selected after consideration of biophysical data and threats to habitats/species/ecosystems; Socioeconomic considerations: The priority areas were selected after consideration biophysical and socio-economic data and were located in places were conservation goals where achieved with minimum socio-economic cost.