Irreplaceable area extends marine conservation hotspot off Tunisia: insights from GPS-tracking Scopoli’s shearwaters from the largest seabird colony in the Mediterranean
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Recent meta-analyses identified conservation hotpots at the scale of the Mediterranean, yet those may be crude by lack of detailed information about the spatial ecology of the species involved. Here, we identify an irreplaceable marine area for >95 % of the world population of the Scopoli’s shearwater (Calonectris diomedea), which is endemic to the Mediterranean and breeds on the island of Zembra off Tunis. To this end, we studied the three-dimensional at-sea movements of 50 breeding adults (over a total of 94 foraging trips) in 2012 and 2013, using GPS and temperature–depth recorders. Feathers were also collected on all birds to investigate their trophic status. Despite Zembra being the largest seabird colony in the Mediterranean (141,000 pairs), the per capita home-range of Scopoli’s shearwaters foraging from this colony was not larger than that of birds from much smaller colonies, indicating highly beneficial feeding grounds in the Gulf of Tunis and off Cap Bon. Considering depleted Mediterranean small pelagic fish stocks, supposed to be Scopoli’s shearwater prey base, we therefore speculate that birds may now also largely feed on zooplankton, something which is supported by our stable isotopic analyses. Crucially, shearwater at-sea feeding and resting areas showed very little overlap with a conservation hotspot recently defined on the western side of the Gulf of Tunis using meta-analyses of species distributions relative to anthropogenic threats. We therefore propose a major extension to this conservation hotspot. Our study stresses the importance of detailed biotelemetry studies of marine megafauna movement ecology for refining large-scale conservation schemes such as marine protected area networks.
KeywordsIsotopic Niche Small Pelagic Fish Important Bird Area Yelkouan Shearwater Isotopic Niche Width
Fieldwork for this study was funded by the PIM initiative (Petites Iles de Méditerranée), while all electronic equipment was provided by the CEFE-CNRS Montpellier. Clara Péron was funded by the French agency for marine protected areas (AAMP) within the “Programme PACOMM, Natura 2000 en mer”. We are grateful to Ana Rodrigues for ‘irreplaceable’ advice, Marta Coll for providing us with the exact outline of the Tunisian conservation hotspot as defined in Coll et al. 2012, to Nory El Ksabi for preparing feathers samples prior to isotopic analyses, and to Owen McFarlane for checking our English. This work would have not been possible without the permission, the human and logistics support of the Tunisian Agence de Protection et d’Aménagement du Littoral (APAL), to whom we are most grateful.
Conflict of interest
The authors declare that they have no conflict of interest.
Data collection was performed under permits from the Agence de Protection et d’Aménagement du Littoral (APAL, Permit No. 1864/12) and from the Direction des Services Vétérinaires (Permit No. 34-369).
- BirdLife International (2010) Marine important bird areas toolkit: standardised techniques for identifying priority sites for the conservation of seabirds at sea. BirdLife International, Cambridge. Version 1.2: February 2011Google Scholar
- Blondel J, Aronson J, Bodiou J, Boeuf G (2010) The Mediterranean region: biological diversity through time and space. Oxford University Press, OxfordGoogle Scholar
- Cecere JG, Catoni C, Maggini I, Imperio S, Gaibani G (2013) Movement patterns and habitat use during incubation and chick-rearing of Cory’s shearwaters (Calonectris diomedea diomedea) (Aves: vertebrata) from Central Mediterranean: influence of seascape and breeding stage. Ital J Zool 80:82–89. doi: 10.1080/11250003.2012.710654 CrossRefGoogle Scholar
- Defos du Rau P, Bourgeois K, Ruffino L, Dromzée S, Ouni R, Abiadh A et al (2012) New assessment of the world’s largest colony of Scopoli’s Shearwater Calonectris diomedea. In: Proceedings of the 13th Medmaravis pan-Mediterranean Symposium, pp 26–28Google Scholar
- Delord K, Barbraud C, Bost CA, Deceuninck B, Lefebvre T, Lutz R, Micol T, Phillips RA, Trathan PN, Weimerskirch H (2014) Areas of importance for seabirds tracked from French southern territories, and recommendations for conservation. Mar Pol 48:1–13. doi: 10.1016/j.marpol.2014.02.019 CrossRefGoogle Scholar
- Drira Z, Belhassen M, Ayadi H, Hamza A, Zarrad R, Bouïn A, Aleya L (2010) Copepod community structure related to environmental factors from a summer cruise in the Gulf of Gabès (Tunisia, eastern Mediterranean Sea). J Mar Biol Assoc UK 90:145–157. doi: 10.1017/S0025315409990403 CrossRefGoogle Scholar
- Fort J, Pettex E, Tremblay Y, Lorentsen S-H, Garthe S, Votier S, Pons J-B, Siorat F, Furness RW, Grecian JW, Bearhop S, Montevecchi WA, Grémillet D (2012) Meta-population evidence of oriented chain migration in northern gannets (Morus bassanus). Front Ecol Environ 10:237–242. doi: 10.1890/110194 CrossRefGoogle Scholar
- GFCM (General Fisheries Commission for the Mediterranean) (2013) Report of the fifteenth session of the Scientific Advisory Committee. Rome, 8–11 April 2013. FAO Fisheries and Aquaculture Report No. 1042. 96 ppGoogle Scholar
- Laneri K, Louzao M, Martinez-Abran A, Arcos J, Belda E, Guallart J, Sánchez A, Giménez M, Maestre R, Oro D (2010) Trawling regime influences longline seabird bycatch in the Mediterranean: new insights from a small-scale fishery. Mar Ecol Prog Ser 420:241–252. doi: 10.3354/meps08847 CrossRefGoogle Scholar
- Masello JF, Mundry R, Poisbleau M, Demongin L, Voigt CC, Wikelski M, Quillfeldt P (2010) Diving seabirds share foraging space and time within and among species. Ecosphere 1(19). doi: 10.1890/ES10-00103.1
- NOAA National Geophysical Data Center. GEODAS grid translator—design a grid. http://www.ngdc.noaa.gov/mgg/gdas/gd_designagrid.html
- Parnell A, Inger R, Bearhop S, Jackson AL (2008) SIAR: stable isotope analysis in R. http://cran.r-project.org/web/packages/siar/
- Péron C, Grémillet D (2014) Habitats marins des puffins de France métropolitaine. Agence des Aires Marines ProtégéesGoogle Scholar
- 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. Biol Conserv 168:210–221. doi: 10.1016/j.biocon.2013.09.006 CrossRefGoogle Scholar
- R Core Team (2014) R: a language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. http://www.R-project.org/
- Ramos R, González-Solís J, Forero MG, Moreno R, Gómez-Díaz E, Ruiz X, Hobson KA (2009) The influence of breeding colony and sex on mercury, selenium and lead levels and carbon and nitrogen isotope signatures in summer and winter feathers of Calonectris shearwaters. Oecologia 159:345–354. doi: 10.1007/s00442-008-1215-7 CrossRefGoogle Scholar
- Ramos R, Granadeiro JP, Rodríguez B, Navarro J, Paiva VH, Bécares J, Reyes-González JM, Fagundes I, Ruiz A, Arcos P, González -Solís J, Catry P (2013) Meta-population feeding grounds of Cory’s shearwaters in the subtropical Atlantic ocean: implications for the definition of marine protected areas based on tracking studies. Divers Distrib 19:1284–1298. doi: 10.1111/ddi.12088 CrossRefGoogle Scholar