Biodiversity and Ecosystem (EO 1)

Common Indicator 3: Species distributional range - Seabirds

Geographical scale of the assessment:
Regional, Mediterranean Sea
Contributing countries:
Mid-Term Strategy (MTS) Core Theme:
2-Biodiversity and Ecosystems
Ecological Objective:
EO1: Biological diversity is maintained or enhanced. The quality and occurrence of coastal and marine habitats and the distribution and abundance of coastal and marine species are in line with prevailing physiographic, hydrographic, geographic and climatic conditions.
IMAP Common Indicator:
Common Indicator 3 (CI3): Species distributional   range (related to seabirds)
Indicator Assessment Factsheet Code:

GES Definition: The species continues to occur in all their Mediterranean natural habitat.

GES Targets:

  • State: No significant shrinkage in the population distribution in the Mediterranean in all indicator species, and for colonial-breeding seabirds (i.e., most species in the Mediterranean).
  • State: For colonies: New colonies are established and the population is encouraged to spread among several alternative breeding sites.



The Mediterranean Sea is considered an important habitat for seabirds, including particularly the Critically Endangered Balearic shearwater (Puffinus mauretanicus), the endemic Yelkouan shearwater (Puffinus yelkouan) and the little tern (Sterna alibifrons). In addition to these species, a number of other seabird species are listed in the Annexes of the Protocol Concerning Specially Protected Areas and Biological Diversity in the Mediterranean of the Barcelona Convention (SPA-BD Protocol).

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Assessment methods               

The breeding distribution range of a seabird species may be assessed using a wide diversity of methodological approaches, most of them quite simple. For the most visible species, such as gulls and terns, simple visual inspection of the most suitable habitat might suffice, as these birds use open nests and have daily activity at the colony. Shags might be more difficult to confirm as breeders, as they often breed sparsely along coastal cliffs and islets and use crevices or caves that may be difficult to detect. In such cases, specific surveys from coastal vantage points or (even better) boats might be useful to confirm their breeding in some sites.

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Results and Status, including trends

Important breeding or feeding grounds for the region’s seabirds are difficult to define because there are only a few countries with active long-term seabird research programmes.

A summary of the presence/absence of the species selected for monitoring is shown in Table 1, per sub-region and country. As with other biodiversity components, seabirds show a higher diversity to the west and north of the Mediterranean basin (Coll et al., 2008).

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The southeast to northwest increasing diversity gradient might be partly influenced by prospection/monitoring effort. For many eastern and southern countries, as well as some Adriatic countries, the information on seabird breeding populations or occurrence at sea is patchy or completely lacking. This might be partly because the birds are actually rare or absent there, but could also be related to lack of data. Particularly little information is available for Algeria, Egypt, Israel, Lebanon, Syria, Cyprus and Turkey, as well as Albania. There is no information from Bosnia-Herzegovina, but this country has extremely limited coastal area, and most likely has no relevant seabird breeding populations. Information from Libya is also patchy, and focuses on terns.

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Key messages 

  • Despite breeding distribution patterns are relatively easy to assess, information is patchy and often lacking.
  • A southeast to northwest increasing diversity gradient has been observed, in agreement with productivity patterns in the region, but this might be confounded by larger data gaps in the southernmost and easternmost countries.

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The reference list includes Works that are not specifically quoted in the text but have been consulted to assess distribution and population figures:

Abelló, P., Arcos, J. M., & Gil De Sola, L. 2003. Geographical patterns of seabird attendance to a research trawler along the Iberian Mediterranean coast. Scientia Marina 67: 69–75.

Afán, I., Y. Aranda, T. Gómez, D. Oro y M.G. Forero. 2010. Nueva colonia de gaviota de Audouin en las islas de Alhucemas. Quercus 25 (290): 22-27.

Arcos, J.M. (compiler) 2011. International species action plan for the Balearic shearwater, Puffinus mauretanicus. SEO/Bird-life & Bird-life International.

Arcos, J.M., Bécares, J., Villero, D., Brotons, L., Rodríguez, B. & Ruiz, A. 2012. Assessing the location and stability of foraging hotspots for pelagic seabirds: an approach to identify marine Important Bird Areas (IBAs) in Spain. Biological Conservation 156: 30-42.

Arcos, J.M., Bécares, J., Cama, A. & Rodríguez, B. 2012. Estrategias marinas, grupo aves: evaluación inicial y buen estado ambiental. MAGRAMA, IEO & SEO/BirdLife.

Baccetti, N., Nissardi, S., Zenatello, M. 2014. GPS-tags reveal strong links to North Africa Larus audouinii breeding in Sardinia. Mediterranean Waterbirds Bulletin 2.

Bianchi, C.N. & Morri, C. 2000. Marine Biodiversity of the Mediterranean Sea: Situation, Problems and Prospects for Future Research. Marine Pollution Bulletin 40: 365-376.

BirdLife International. 2013. IUCN Red List for birds. Downloaded from

BirdLife International. 2014. Important Bird Areas factsheet: Malta-Gozo Channel. Available at

BirdLife International. 2016. IUCN Red List for birds. Downloaded from

Bourgeois, K. & Vidal, E. 2008. The Endemic Mediterranean shearwater Puffinus yelkouan: distribution, threats and a plea for new data. Oryx 42: 187-194.

Bourgeois K., P. Gillet, I. Budinski, B. Cadiou, D. Portolou, J. Borg & J. Sultana. 2012. Yelkouan shearwater Puffinus yelkouan, updated state of knowledge and conservation of the nesting populations of the Small Mediterranean Islands Initiative PIM, 24 p.

Boyd, I., Wanless, S. & Camphuysen, C.J. 2006. Top predators in marine ecosystems: their role in monitoring and management. Cambridge University Press.

Coll M., Piroddi C., Steenbeek J., Kaschner K., Ben Rais Lasram F., et al. (2010). The Biodiversity of the Mediterranean Sea: Estimates, Patterns, and Threats. PLoS ONE 5(8): e11842. doi:10.1371/journal.pone.0011842

Croxall, J.P., S.H.M. Butchart, B. Lascelles, A.J. Stattersfield, B. Sullivan, A. Symes & P. Taylor. 2012. Seabird conservation status, threats and priority actions: a global assessment. Bird Conservation International 22: 1-34.

Gabrié C., et al., (2012) 'The Status of the Marine Protected Areas in the Mediterranean Sea', MedPAN & RAC/SPA. Ed: MedPAN Collection.

Fric, J., Portolou, D., Manolopoulos, A. & Kastritis, T. 2012. Important Areas for Seabirds in Greece. LIFE07NAT/GR/000285. Hellenic Ornithological Society (HOS/BirdLife Greece). Athens.

Gutiérrez, R. & Figuerola, J. 1995. Wintering distribution of the Balearic Shearwater (Puffinus yelkouan mauretanicus) off the northeastern coast of Spain. Ardeola 42(2): 161-166.

Ledant J.P., Jacob J.P., Jacobs P., Malher F., Ochando B. & Roché J. 1981. Mise à jour de l’avifaune algérienne. Le Gerfaut 7: 295–398.

Louzao, M., Hyrenbach, K. D., Arcos, J. M., Abelló, P., Sola, L. G. De, & Oro, D. 2006. Oceanographic habitat of a critically endangered Mediterranean Procellariiform: implications for the design of Marine Protected Areas. Ecological Applications 16 (5): 1683–1695.

Louzao, M., Becares, J., Rodriguez, B., Hyrenbach, K., Ruiz, A., & Arcos, J. (2009). Combining vessel-based surveys and tracking data to identify key marine areas for seabirds. Marine Ecology Progress Series, 391.

Louzao, M., García, D., Rodríguez, B. & Abelló, M. 2015. Marine Ornithology 43: 49-51

Meier, R. E., Wynn, R. B., Votier, S. C., Mcminn Grivé, M., Rodríguez, A., Maurice, L., Guilford, T. 2015. Consistent foraging areas and commuting corridors of the critically endangered Balearic shearwater Puffinus mauretanicus in the northwestern Mediterranean. Biological Conservation 190, 87–97.

Mínguez, E., Oro, D., de Juana, E., & Martínez-Abraín, A. 2003. Mediterranean seabird conservation: what can we do? Scientia Marina 67: 3–6.

Paleczny M, Hammill E, Karpouzi V, Pauly D (2015) Population Trend of the World’s Monitored Seabirds, 1950-2010. PLoS ONE 10(6): e0129342. doi:10.1371/journal.pone.0129342

Parsons, M., Mitchell, I., Butler, A., Ratcliffe, N., Frederiksen, M., Foster, S., & Reid, J. B. 2008. Seabirds as indicators of the marine environment. – ICES Journal of Marine Science 65: 1520–1526.

Péron, C., Grémillet, D., Prudor, A., Pettex, E., Saraux, C., Soriano-Redondo, A., Authier, M. & Fort, J., 2013. Importance of coastal Marine Protected Areas for the conservation of pelagic seabirds: The case of Vulnerable yelkouan shearwaters in the Mediterranean Sea. Biological Conservation 168: 210-221.

Piatt, J.F., Sydeman, W.J. & Wiese, F. 2007. Introduction: a modern role for seabirds as indicators. Marine Ecology Progress Series 352: 199-204.

Raine, A. F., Raine, H., Borg, J. J., & Meirinho, A. 2011. Post-fledging dispersal of Maltese Yelkouan Shearwaters Puffinus yelkouan. Ringing and Migration 26(2): 94–100.

Raine, A. F., Borg, J. J., Raine, H., & Phillips, R. A. 2013. Migration strategies of the Yelkouan Shearwater Puffinus yelkouan. Journal of Ornithology 154(2): 411–422.

Ruffino et al., (2009). Invasive rats and seabirds after 2,000 years of an unwanted coexistence on Mediterranean islands. Biological Invasions 11(7):1631-1651 · August 2009

STECF (Scientific, Technical and Economic Committee for Fisheries). 2016. Mediterranean assessments part 1 (STECF-16-22); Publications Office of the European Union, Luxembourg

Tarzia, M., Hagen, C. & Wanless R. 2015. Review of the Status, Threats and Conservation Action Priorities for the Seabird Populations Covered by the Agreement. Report to the African-Eurasian Waterbird Agreement. 150 pp.

UNEP-MAP-RAC/SPA. 2010. Report presenting a georeferenced compilation on bird important areas in the Mediterranean open seas. By Requena, S. and Carboneras, C. Ed. RAC/SPA, Tunis: 39pp.

UNEP/MAP (2015). Strategic Action Programme to Address Pollution from Land Based Activities in the Mediterranean region (SAP-MED) and National Action Plans’ (NAP) implementation 2000 – 2015, UNEP/MAP, Athens, 2015.

UNEP/MAP (2016). Mediterranean Strategy for Sustainable Development 2016-2025. Valbonne. Plan Bleu, Regional Activity Centre.

UNEP-MAP-RAC/SPA. 2014. Status of Seabirds in the Alboran Sea. By J.M.Arcos. Draft internal report for the purposes of the Mediterranean Regional Workshop to Facilitate the Description of Ecologically or Biologically Significant Marine Areas, Malaga, Spain, 7-11 April 2014.

UNEP/MAP /SPA/RAC, 2017, Draft updated Action Plan for the Conservation of Marine and Coastal Bird Species listed in Annex II of the Protocol concerning Specially Protected Areas and Biological Diversity in the Mediterranean, UNEP(DEPI)/MED WG.431/5.

Yesou, P., Sultana, J., Walmsley, J. & Azafzaf, H. 2016. Conservation of Marine and Coastal Birds in the Mediterranean. Proceedings of the UNEP-MAP-RAC/SPA Symposium, Hammamet, Tunisia 20-22 February 2015. 180 pp.

Zotier, R., Bretagnolle, V. & Thibault, J.C. 1999. Biogeography of the marine birds of a confined sea, the Mediterranean. Journal of Biogeography 26, 297-313.