Northern Adriatic IMMA

Area Size

33 437 km2

Qualifying Species and Criteria

Common bottlenose dolphin – Tursiops truncatus

Criterion A; B (2); C (1); D (1)

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The shallow continental shelf area of the Northern Adriatic hosts an estimated 6,000 Vulnerable Mediterranean common bottlenose dolphins (Tursiops truncatus). Genetic evidence reveals a fine-scale genetic structure, with differentiation between north and south-central areas, as well as between the west and east coasts. In addition, evidence suggests that the Gulf of Trieste hosts another unit, with significant genetic differentiation from the rest of the Adriatic Sea. Residency patterns have been identified along coastal areas of the eastern Adriatic with at least three distinct local communities across the Gulf of Trieste, the Kvarnerić, and north Dalmatia. Three EU Natura 2000 Special Areas of Conservation have been designated for common bottlenose dolphins in Croatian waters.

Description of Qualifying Criteria

Criterion A – Species or Population Vulnerability

The IUCN classifies the Mediterranean subpopulation of common bottlenose dolphin as Vulnerable on Red list of Threatened Species. These animals live in a region of high anthropogenic use. The continental shelf of northern Adriatic is one of the most heavily exploited area for fisheries (trawling, shells dredging, pelagic trawling and purse-seining, set nets, longlines), shipping, and pollution in the Mediterranean. In addition, tourism and recreational traffic is increasing during the summer months, causing physical disturbance and increased noise levels.

Criterion B: Distribution and Abundance

Sub-criterion B2: Aggregations

Aerial surveys in summers of 2010 and 2013 produced high estimates of abundance for common bottlenose dolphin in the area. Estimated abundance of Tursiops truncatus based on 2010 aerial survey, corrected for availability and perception bias (group size, time on surface), in the shallow continental shelf area of northern Adriatic was 6,577 (CV 20,3%; 95% CI 4,412-9,805). The high abundance has been further confirmed with predicted abundance using surface density models.

Criterion C: Key Life Cycle Activities

Sub-criterion C1: Reproductive Areas

Species is present year-round in the area, hence reproduction takes place within the area. Apart from aerial surveys and dedicated long-term photo-identification research surveys confirming observations of young animals, year-round monitoring of bycatch in midwater pair trawling fleet of Italy, operating in the northern Adriatic between 2006-2013 produced thousands of observations of different group sizes of T. truncatus in the whole northern Adriatic basin throughout the year. Numerous observations of newborns, calves and juvenile animals confirm that further.

Criterion D: Special Attributes  

Sub-criterion D1: Distinctiveness

Tursiops truncatus seems almost uniformly distributed throughout the Adriatic basin. However, genetic evidence rejected the hypothesis of a single stock. Pairwise estimates of genetic differentiation at 17 microsatellite loci, and mitochondrial DNA, revealed diverse levels of genetic differentiation among the Adriatic Sea. The results suggest that bottlenose dolphin exhibits population structures that correspond well to the main Adriatic basins, and that the genetic differentiation is not correlated to geographic distances. At a nuclear level, common bottlenose dolphins revealed a fine-scale genetic structure, showing a differentiation between north and central-south areas, as well as between the west and east coast. In addition, individuals from the Gulf of Trieste seem to belong to a group of animals significantly differentiated from the rest of the Adriatic Sea.

Supporting Information

Fortuna, C.M., Acquarone, M., Annunziatellis, A. et al. 2013. MSFD Supporting document on the Initial Assessment on Cetaceans, including methodology, data used and results. ISPRA, Rome, p. 62.

Fortuna, C.M., Holcer, D., Filidei Jr, E., Donovan, G.P., Tunesi, L., 2011. The first cetacean aerial survey in the Adriatic Sea: summer 2010. 7th Meeting of the ACCOBAMS Scientific committee, p. 16.

Fortuna, C.M., Filidei Jr, E., 2013. Annual Report on the implementation of Council Regulation (EC) 812/2004 – 2012. Rapporto tecnico preparato per il Ministero delle politiche agricole, alimentari e forestali. ISPRA

Fortuna, C.M., Mackelworth, C.P., Holcer, D., 2014. Toward the identification of EBSAs in the Adriatic Sea: hotspots of megafauna. Mediterranean Regional Workshop to Facilitate the Description of Ecologically or Biologically Significant Marine Areas (EBSAs). Convention on Biological Diversity, Málaga, Spain, p. 5.

Fortuna, C.M., Holcer, D., Mackelworth, C.P., 2015. Conservation of cetaceans and sea turtles in the Adriatic Sea: status of species and potential conservation measures. Report produced under WP7 of the NETCET project, IPA Adriatic Cross-border Cooperation Programme, p. 135.

Genov, T. (2011) Ecology of the bottlenose dolphin (Tursiops truncatus) in the northern Adriatic. Graduation thesis, University of Ljubljana.

Genov, T., Angelini, V., Hace, A. et al. 2015. Mid-distance re-sighting of a common bottlenose dolphin in the northern Adriatic Sea: insight into regional movement patterns. J. Mar. Biol. Assoc. U.K. 96, 909-914.

Gaspari, S., Holcer, D., Mackelworth, P., Fortuna, C., Frantzis, A., Genov, T., Vighi, M., Natali, C., Rako, N., Banchi, E., Chelazzi, G., Ciofi, C., 2013. Population genetic structure of common bottlenose dolphins (Tursiops truncatus) in the Adriatic Sea and contiguous regions: implications for international conservation. Aquat. Conserv.: Mar. Freshwat. Ecosyst. 25, 212–222.

Gaspari, S., Scheinin, A., Holcer, D., Fortuna, C., Natali, C., Genov, T., Frantzis, A., Chelazzi, G., Moura, A., 2015. Drivers of population structure of the bottlenose dolphin (Tursiops truncatus) in the Eastern Mediterranean Sea. Evolutionary Biology 42, 177–190.

Gomerčić, T., Huber, Đ., Đuras Gomerčić, M., Gomerčić, H., 2011. Presence of the Mediterranean Monk Seal (Monachus monachus) in the Croatian Part of the Adriatic Sea. Acquatic Mammals 37, 243-247.

Holcer, D., Fortuna, C.M., Mackelworth, P.C., 2014. Current state of knowledge of Cetacean species in the Adriatic Sea. Scientific Committee of The International Whaling Commission. IWC, Bled, Slovenia, p. 19.

Holcer, D., Mackelworth, C.P., Fortuna, C.M.,2014. Status and Conservation of Cetaceans in the Adriatic Sea – draft. Mediterranean Regional Workshop to Facilitate the Description of Ecologically or Biologically Significant Marine Areas. UNEP-MAP-RAC/SPA, Malaga, Spain, p. 70.

Holcer, D., Fortuna, C.M., 2015. Atlas of Cetacean and sea turtle distribution in the Adriatic Sea. Blue World Institute, Veli Lošinj, p. 24.

Cushman-Rosin, B., Gačić, M., Poulani, P., Artegiani, A., (Eds), 2001. Physical oceanography of the Adriatic Sea. Past, present and future. Kluwer Academic Publishers, Dordrecht.


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