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Partitioning of the Pelagos Sanctuary (north-western Mediterranean Sea) into hotspots and coldspots of cetacean distributions

  • Aurélie Moulins (a1), Massimiliano Rosso (a1), Marco Ballardini (a2) and Maurizio Würtz (a3)


This study used Monte Carlo methods to generate simulations that considered the effort distribution to determine the locations of significant aggregations of cetacean sightings inside the northern Pelagos Sanctuary (north-western Mediterranean Sea). For three years, monitoring has been conducted from five motor vessels covering about 30,050 km. The most frequently encountered species were the striped dolphin Stenella coeruleoalba representing 64.7% of all sightings, the fin whale Balaenoptera physalus (17.0%), Cuvier's beaked whale Ziphius cavirostris (9.9%), Risso's dolphin Grampus griseus (4.3%) and the sperm whale Physeter catodon (2.2%). Sightings' positions and effort coverage were distributed over a grid of 5′ longitude and 5′ latitude. Spatial concentrations of sightings were analysed according to the distribution of effort to identify ‘hotspots’ (locations where the species occurred at a significantly greater frequency than expected), and ‘coldspots’ (locations with a significantly lower frequency than expected). Most fin whale hotspots (14) were located on the bathyal plain between 2000 and 2500 m, four hotspots were around the 1000 m isobaths, and one is located close to the seamount off Genoa. Fin whale coldspots were mainly along the coast. Striped dolphin hotspots were widely distributed over two main areas, in waters with depths between 2000 and 2500 m and at the continental slope; coldspots for this species were also mainly along the coast in the northern part of the study area. Many hotspots were found in the Genoa Canyon, and hotspots of striped dolphins, Cuvier's beaked whales, sperm whales and Risso's dolphins overlapped in this region. Some of the hotspots of Cuvier's beaked whales were identified at the seamount in the study area, where no other species was sighted frequently. Risso's dolphin hotspots were mainly near the 1000 m isobath. For sperm whales, several hotspots were identified: three associated with steep slope features (such as canyons or the continental slope), and one was in the centre of the flat area of Pelagos where the depth is 2500 m. This study highlights the ecological importance of particular locations inside the Pelagos Sanctuary—locations that should be protected from anthropogenic degradations for marine mammal conservation.


Corresponding author

Correspondence should be addressed to: Aurélie Moulins, Interuniversity Research Center for Environmental Monitoring—CIMA, Via Cadorna 7, 17100 Savona, Italy email:


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Aïssi, M., Celona, A., Comparetto, G., Mangano, R., Würtz, M. and Moulins, A. (2008) Large-scale seasonal distribution of fin whales (Balaenoptera physalus) in the Central Mediterranean Sea. Journal of the Marine Biological Association of the United Kingdom 88, in press.
Andersen, V., Vilan, P., Caparroy, P. and Gubanova, A. (2001) Zooplankton community during the transition from spring bloom to oligotrophy in the open NW Mediterranean and effects of wind events. 1. Abundance and specific composition. Journal of Plankton Research 23, 227242.
Archer, F.I. (1996) Morphological and genetic variation of striped dolphins (Stenella coeruleoalba Meyen 1833). PhD thesis, University of California, San Diego, USA.
ARPAL and Regione Liguria (2002) Relazione sullo stato dell'ambiente in Liguria: 1999–2000–2001. Technical Report, Genoa, 432 pp. []
Astraldi, M., Bianchi, C.N., Gasparini, G.P. and Morri, C. (1995) Climatic fluctuations, current variability, and marine species distribution: a case study in the Ligurian Sea (North-West Mediterranean). Oceanologica Acta 18, 139149.
Astraldi, M. and Gasparini, G.P. (1992) The seasonal characteristics of the circulation in the north Mediterranean basin and their relationship with the atmospheric–climatic conditions. Journal of Geophysical Research 97, 95319540.
Astruc, G. and Beaubrun, P. (2001) Fin whale (Balaenoptera physalus), summer feeding in the north-western mediterranean sea. In Evans, P.G.H. and O'Boyle, E. (eds) Proceedings of the fifteenth annual conference of the European Cetacean Society 6–10 May 2001. Cambridge: European Cetacean Society, pp. 289291.
Bérubé, M. et al. (1998) Population genetic structure of North Atlantic, Mediterranean Sea and Sea of Cortez fin whales, Balaenoptera physalus (Linnaeus 1758): analysis of mitochondrial and nuclear loci. Molecular Ecology 7, 585599.
Béthoux, J.-P., Gentili, B., Raunet, J. and Tailliez, D. (1990) Warming trend in the western Mediterranean deep water. Nature 347, 660662.
Béthoux, J.-P., Prieur, L. and Bong, J.-H. (1988) Le courant Ligure au large de Nice. Oceanologica Acta, Special Issue, 5967.
Bianchi, C.N. (2007) Biodiversity issues for the forthcoming tropical Mediterranean Sea. Hydrobiologia 580, 721.
Blanco, C., Azanar, J. and Raga, J.A. (1995) Cephalopods in the diet of striped dolphin Stenella coeruleoalba from the western Mediterranean during an epizootic in 1990. Journal of Zoology 237, 151158.
Blanco, C. and Raga, J.A. (2000) Cephalopod prey of two Ziphius cavirostris (Cetacea) stranded on the western Mediterranean coast. Journal of the Marine Biological Association of the United Kingdom 80, 381382.
Boucher, J., Ibanez, F. and Prieur, L. (1987) Daily and seasonal variations in the spatial distribution of zooplankton populations in relation to the physical structure in the Ligurian Sea Front. Journal of Marine Research 45, 133173.
Bourret, V.J.R., Macé, M.R.J.M. and Crouau-Roy, B. (2007) Genetic variation and population structure of western Mediterranean and northern Atlantic Stenella coeruleoalba populations inferred from microsatellite data. Journal of the Marine Biological Association of the United Kingdom 87, 265269.
Caddy, J.F., Refk, R. and Do-Chi, T. (1995) Productivity estimates for the Mediterranean: evidence of accelerating ecological change. Ocean Coastal Management 26, 118.
Davis, R.W. et al. (2002) Cetacean habitat in the northern oceanic Gulf of Mexico. Deep-Sea Research I 49, 121142.
Dalebout, M.L., Robertson, K.M., Frantzis, A., Engelhaupt, D., Mignucci-Giannoni, A.A., Rosario-Delestre, R.J. and Baker, C.S. (2005) Worldwide structure of mtDNA diversity among Cuvier's beaked whales (Ziphius cavirostris): implications for threatened populations. Molecular Ecology 14, 33533371.
Drouot, V., Bérubé, M., Gannier, A., Goold, J.C., Reid, R.J. and Palsbøll, P.J. (2004) A note on genetic isolation of Mediterranean sperm whales (Physeter macrocephalus) suggested by mitochondrial DNA. Journal of Cetacean Research and Management 6, 2932.
Drouot, V. and Gannier, A. (2004) Diving and feeding behavior of sperm whales (Physeter macrocephalus) in the Northwestern Mediterranean Sea. Aquatic Mammals 30, 419426.
Drouot-Dulau, V. and Gannier, A. (2007) Movements of sperm whale in the western Mediterranean Sea: preliminary photo-identification results. Journal of the Marine Biological Association of the United Kingdom 87, 195200.
Engelhaupt, D. (2004) Molecular ecology of the sperm whale in the Gulf of Mexico, Mediterranean Sea and North Atlantic. PhD thesis, University of Durham, UK.
Estrada, M. (1996) Primary production in the northwestern Mediterranean. Scientia Marina, Special Issue 2, 60, 5564.
European Environment Agency (1999) State and pressures of the marine and coastal Mediterranean environment. Technical Report. Environmental Issues Series, Luxembourg, no. 5, pp. 44. []
Franqueville, C. (1971) Macroplancton profond (invertébrés) de la Méditerranée nord-occidentale. Tethis 3, 1156.
Gannier, A. (1999) Diel variations of striped dolphin distribution off the French Riviera (Northwestern Mediterranean Sea). Aquatic Mammal 25, 123134.
Gannier, A. (2002) Summer distribution of fin whales (Balaenoptera physalus) in the northwestern Mediterranean marine mammals sanctuary. Revue d'Écologie (la Terre et la Vie), 57, 135150.
Gannier, A. (2005) Summer activity pattern of fin whales (Balaenoptera physalus) in the northwestern Mediterranean Pelagos Sanctuary. Mésogée 61, 3541.
Gannier, A. and Praca, E. (2007) SST fronts and the summer sperm whale distribution in the north-west Mediterranean Sea. Journal of the Marine Biological Association of the United Kingdom 87, 187193.
Gaspari, S., Airoldi, S. and Hoelzel, A. (2007) Risso's dolphins (Grampus griseus) in UK waters are differentiated from a population in the Mediterranean Sea and genetically less diverse. Conservation Genetics 8, 727732.
Gordon, J.C.D., Matthews, J.N., Panigada, S., Gannier, A., Borsani, F.J. and Notarbartolo di Sciara, G. (2000) Distribution and relative abundance of striped dolphins, and distribution of sperm whales in the Ligurian Sea cetacean sanctuary. Journal of Cetacean Research and Management 2, 2736.
Haury, L., Frey, C., Newland, C. and Genin, A. (2000) Zooplankton distribution around four eastern North Pacific seamounts. Progress in Oceanography 45, 69105.
Johnson, M., Madsen, P.T., Zimmer, W., Aguilar de Soto, N. and Tyack, P.L. (2004) Beaked whales echolocate on prey. Proceedings of the Royal Society B (Special Issue) 271, S383S386.
Jones, P.J.S. (1994) A review and analysis of the objectives of marine nature reserves. Ocean and Coastal Management 24, 149178.
Littaye, A., Gannier, A., Laran, S. and Wilson, J.P.F. (2004) The relationship between summer aggregation of fin whales and satellite-derived environmental conditions in the northwestern Mediterranean Sea. Remote Sensing of the Environment 90, 4452.
MacLeod, C.D. and Mitchell, G. (2006) Key areas for beaked whales worldwide. Journal of Cetacean Research and Management 7, 309322.
Manca, B., Burca, M., Giorgetti, A., Coatanoan, C., Garcia, M.J. and Iona, A. (2004) Physical and biochemical averaged vertical profiles in the Mediterranean regions: an important tool to trace the climatology of water masses and to validate incoming data from operational oceanography. Journal of Marine Systems 48, 83116.
McGehee, D.E., Demer, D.A. and Warren, J.D. (2004) Zooplankton in the Ligurian Sea: Part I. Characterization of their dispersion, relative abundance and environment during summer 1999. Journal of Plankton Research 26, 14091418.
Meinesz, A., Lefevre, J.R. and Astier, J.M. (1991) Impact of coastal development on the infralittoral zone along the southeastern Mediterranean shore of continental France. Marine Pollution Bulletin 23, 343347.
Millot, C. (1999) Circulation in the Western Mediterranean Sea. Journal of Marine Systems 20, 423442.
Monestiez, P., Dubroca, L., Bonnin, E., Durbec, J.-P. and Guinet, C. (2006) Geostatistical modelling of spatial distribution of Balaenoptera physalus in the Northwestern Mediterranean Sea from sparse count data and heterogeneous observation efforts. Ecological Modelling 193, 615628.
Moulins, A., Rosso, M., Nani, B. and Würtz, M. (2007) Aspects of distribution of Cuvier's beaked whale (Ziphius cavirostris) in relation to topographic features in the Pelagos Sanctuary (north-western Mediterranean Sea). Journal of the Marine Biological Association of the United Kingdom 87, 177186.
Moulins, A. and Würtz, M. (2005) Occurrence of a herd of female sperm whales and their calves (Physeter macrocephalus), off Monaco, in the Ligurian Sea. Journal of the Marine Biological Association of the United Kingdom 85, 213214.
Nesis, K.N. (1993) Cephalopods of seamounts and submarine ridges. In Okutani, T. et al. (ed.) The recent advances in cephalopod fishery biology. Tokyo: Tokai University Press, pp. 365373.
Notarbartolo di Sciara, G., Agardy, T., Hyrenbach, D.K., Scovazzi, T. and Van Klaveren, P. (2007) The Pelagos Sanctuary for Mediterranean marine mammals. Aquatic Conservation: Marine and Freshwater Ecosystems 17, in press.
Panigada, S., Notarbartolo di Sciara, G., Zanardelli Panigada, M., Airoldi, S., Borsani, J.F. and Jahoda, M. (2005) Fin whales (Balaenoptera physalus) summering in the Ligurian Sea: distribution, encounter rate, mean group size and relation to physiographic variables. Journal of Cetacean Research and Management 7, 137145.
Panigada, S., Zanardelli, M., Canese, S.P. and Jahoda, M. (1999) How deep can baleen whales dive? Marine Ecology Progress Series 187, 309311.
Redfern, J.V. et al. (2006) Techniques for cetacean–habitat modeling. Marine Ecology Progress Series 310, 271295.
Santos, M.B., Pierce, G.J., Herman, J., López, A., Guerra, A., Mente, E. and Clarke, M.R. (2001) Feeding ecology of Cuvier's beaked whale Ziphius cavirostris: a review with new information on the diet of this species. Journal of the Marine Biological Association of the United Kingdom 81, 687694.
Valle-Levinson, A., Castro, A.T., Gutiérrez de Velasco, G. and Gonalez Armas, R. (2004) Diurnal vertical motions over a seamount of the southern Gulf of California. Journal of Marine Systems 50, 6177.
Viale, D. (1985) Cetaceans in the Northwestern Mediterranean: their place in the ecosystem. In Barnes, M. (ed.) Oceanography and marine biology: an annual review. Aberdeen: Aberdeen University Press, pp. 491571.
Watwood, S.L., Miller, P.J.O., Johnson, M., Madsen, P.T. and Tyack, P.L. (2006) Deep-diving foraging behaviour of sperm whales (Physeter macrocephalus). Journal of Animal Ecology 75, 814825.
Würtz, M. and Marrale, D. (1993) Food of striped dolphin, Stenella coeruleoalba, in the Ligurian Sea. Journal of the Marine Biological Association of the United Kingdom 73, 571578.
Yen, P.P.W., Sydeman, W.J. and Hyrenbach, K.D. (2004) Marine bird and cetacean associations with bathymetric habitats and shallow-water topographies: implications for trophic transfer and conservation. Journal of Marine Systems 50, 7999.


Partitioning of the Pelagos Sanctuary (north-western Mediterranean Sea) into hotspots and coldspots of cetacean distributions

  • Aurélie Moulins (a1), Massimiliano Rosso (a1), Marco Ballardini (a2) and Maurizio Würtz (a3)


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