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Contents  

Dolphin abundance and distribution
Interactions between dolphins and fisheries
Impact of human activities
Supporters
Collaborations and agreements
Contributions on Adriatic cetaceans
Field station
Boats
Photo album

 

Dolphin abundance and distribution

 
 
 

We investigate the distribution, movements, habitat use, population abundance, status and trends of dolphins along the entire coast of the Veneto region, up to 12 nautical miles (22 km) offshore. The study area covers approximately 3000 km2.

To identify important dolphin habitat we use advanced analytical tools such as distribution modelling, based on navigation along transects that produces presence/absence data weighted on observation effort and sea conditions.

Regular monitoring contributes to the understanding of cause-effect mechanisms and to the identification of management strategies that may ensure dolphin conservation.

 
 
 

Surveys are conducted from small boats, to minimise disturbance to the dolphins and ease individual photo-identification. This research method — relatively simple but powerful and uninvasive — relies on high-resolution digital photographs of long-term natural marks on the animals' dorsal fins.

The ongoing photo-identification effort generates an increasingly comprehensive catalogue of individual common bottlenose dolphins (Tursiops truncatus) occuring in this part of the Adriatic.

30,000 dorsal fin photographs have been filed so far, resulting in a catalogue of about 520 individuals photo-identified off the coast of Veneto. This information allowed to estimate the abundance of dolphins occurring in these waters on a monthly and annual basis. Such estimates also include those individuals that, not having natural markings on their dorsal fins, cannot be photo-identified.

 
 
 
 
Interactions between dolphins and fisheries
 
 
 

Off the coast of Veneto bottlenose dolphins regularly interact with fishing boats, especially otter trawlers and midwater pair trawlers. These dolphins may forage behind trawlers while the nets are being dragged and hauled.

Our work at sea allows to study this opportunistic behaviour, contributing to the identification of problems and solutions.

 
 
 

 
Impact of human activities
 
 
Human impact on the waters off Veneto is considerable.
 
 

Italy's longest rivers, Po and Adige, end here, discharging nutrient-rich waters into the Adriatic Sea. Their hydrographic basins encompass much of northern Italy, also conveying land pollutants.

Figure: the hydrographic basins of rivers Po and Adige

 

The commercial fishing fleet, largely composed of trawlers, is among the largest in Italy. Fishing pressure in the northern Adriatic has been high for decades and fish populations are in crisis as a result of the over-exploitation and mismanagement of marine resources.

In recent years, offshore mariculture has boomed, with large portions of sea being set apart for mussel farming. The region's ports host thousands of pleasure and sport-fishing boats. A large liquid natural gas offshore terminal ('Adriatic LNG'), built in 2009, is located in the center of the study area.

Despite an intensive use and exploitation of the sea, little is known about present human impact on cetaceans in the northern Adriatic. Our work contributes to a better understanding of the impacts of fisheries, aquaculture and industrial activities on the dolphins of Veneto.

 

 
 
Supporters
 
Dolphin research and conservation projects conducted by DBC in Italy and Greece — including Dolphins of Veneto — have been consistently supported by:
 
Collaborations and agreements
 
 
 
 
Contributions on Adriatic cetaceans
 

(in chronological order)

Notarbartolo di Sciara G., Bearzi G., Bonomi L. 1991. Bottlenose dolphins off Croatia: Photoidentification and behavioral observations. 9th Biennial Conference on the Biology of Marine Mammals, Chicago, Illinois, 5-9 December 1991.

Bearzi G., Notarbartolo di Sciara G., Bonomi L. 1992. Bottlenose dolphins off Croatia: a socio-ecologic study. European Research on Cetaceans 6:130-133.

Notarbartolo di Sciara G., Bearzi G. 1992. Cetaceans in the northern Adriatic Sea: past, present, and future. Rapports de la Commission Intérnationale de la Mer Méditerranée 33:303.

Bearzi G., Notarbartolo di Sciara G., Lauriano G. 1993. The Cres-Losinj Dolphin Reserve: Proposal for the institution of a marine reserve in the waters adjacent to the east coast of Cres and Losinj. Tethys Research Institute Report TRI/ADP 93-01. 18 pp.

Bearzi G., Notarbartolo di Sciara G., Politi E., Lauriano G. 1993. Social ecology and behavior of bottlenose dolphins in the waters adjacent to the island of Losinj (Croatia). 10th Biennial Conference on the Biology of Marine Mammals, Galveston, Texas, 12-15 November 1993.

Notarbartolo di Sciara G., Bearzi G. 1993. Cetaceans in the northern Adriatic Sea: past, present and future. Proceedings of the 4th Congress of Croatian Biologists. Croatian Biological Society, Zagreb. Pp. 86-87.

Peharda M., Bearzi G. 1993. Surfacing patterns of bottlenose dolphins in the Cres-Losinj area (Northern Adriatic Sea). European Research on Cetaceans 7:73-76.

Bearzi G. 1994. Dolphins of the Cres-Losinj Archipelago. An illustrated educational book for children. Published by the Tethys Research Institute and Europe Conservation in Croatian, Italian, German and French. 29 pp.

Bearzi G., Notarbartolo di Sciara G., Politi E., Lauriano G. 1994. Ecology and behaviour of bottlenose dolphins (Tursiops truncatus) near the islands of Losinj and Cres (Croatia). Pp. 399-400 in the Proceedings of the Fifth Congress of Croatian Biologists, Pula, Croatia, 3-7 October 1994.

Notarbartolo di Sciara G. Holcer D., Bearzi G. 1994. Past and present status of cetaceans in the northern and central Adriatic Sea. Proceedings of the 5th Congress of Croatian Biologists. Croatian Biological Society, Zagreb. Pp. 401-402.

Bearzi G., Notarbartolo di Sciara G. 1995. A comparison of the present occurrence of bottlenose dolphins, Tursiops truncatus, and common dolphins, Delphinus delphis, in the Kvarneric (northern Adriatic Sea). Annales (Annals for Istrian and Mediterranean Studies) 7:61-68.

Bearzi G., Politi E., Notarbartolo di Sciara G. 1996. Photoidentification-based short-term tracking of bottlenose dolphins resident in the Kvarneric (northern Adriatic Sea). European Research on Cetaceans 9:132-138.

Bearzi G. 1997. A "remnant" common dolphin observed in association with bottlenose dolphins in the Kvarneric (northern Adriatic Sea). European Research on Cetaceans 10:204.

Bearzi G., Notarbartolo di Sciara G. 1997. Bottlenose dolphins following bottom trawlers in the Kvarneric (northern Adriatic Sea). European Research on Cetaceans 11:202-204.

Bearzi G., Notarbartolo di Sciara G., Politi E. 1997. Social ecology of bottlenose dolphins in the Kvarneric (northern Adriatic Sea). Marine Mammal Science 13(4):650-668.

Bearzi G., Politi E., Notarbartolo di Sciara G. 1997. Il comportamento diurno del tursiope nel Quarnerolo (Adriatico Settentrionale). III National Meeting on Cetaceans, Napoli, Italy, 5-6 December 1997.

Fortuna C.M., Bearzi G., Delfino G. 1997. Surfacing pattern of bottlenose dolphins following bottom trawlers in the Kvarneric (northern Adriatic Sea). European Research on Cetaceans 10:244.

Fortuna C.M., Bearzi G., Notarbartolo di Sciara G. 1997. Analisi dei modelli respiratori di tursiopi (Tursiops truncatus, Montagu, 1821) in Adriatico settentrionale. III National Meeting on Cetaceans, Napoli, Italy, 5-6 December 1997.

Oehen S., Bearzi G., Borsani J.F. 1997. Acoustic behaviour of free-ranging bottlenose dolphins in the Kvarneric (northern Adriatic Sea). European Research on Cetaceans 11:230.

Wilson B., Arnold H., Bearzi G., Fortuna C., Gaspar R., Liret C., Pribanic S., Read A.J., Ridoux V., Urian K.W., Wells R.S., Wood C., Thompson P.M., Hammond P.S. 1997. A comparison of epidermal disease in eight populations of bottlenose dolphins. European Research on Cetaceans 11:268.

Wilson B., Pribanic S., Fortuna C.M., Bearzi G. 1997. Epidermal lesions on free-ranging bottlenose dolphins in the Kvarneric. European Research on Cetaceans 11:269.

Bearzi G., Fortuna C.M., Notarbartolo di Sciara G. 1998. Unusual sighting of a striped dolphin (Stenella coeruleoalba) in the Kvarneric, Northern Adriatic Sea. Natura Croatica 7(3):169-176.

Bearzi G., Politi E., Notarbartolo di Sciara G. 1999. Apparent lack of seasonal patterns in the behaviour of bottlenose dolphins in the Kvarneric (northern Adriatic Sea). European Research on Cetaceans 12:202.

Bearzi G., Politi E., Notarbartolo di Sciara G. 1999. Diurnal behavior of free-ranging bottlenose dolphins in the Kvarneric (northern Adriatic Sea). Marine Mammal Science 15(4):1065-1097.

Fortuna C.M., Bearzi G., Notarbartolo di Sciara G. 1999. Analysis of respiration patterns of bottlenose dolphins observed in the Kvarneric (northern Adriatic Sea, Croatia). European Research on Cetaceans 12:151-155.

Wilson B., Arnold H., Bearzi G., Fortuna C., Gaspar R., Ingram S., Liret C., Pribanic S., Read A.J., Ridoux V., Schneider K., Urian K.W., Wells R.S., Wood C., Thompson P.M., Hammond P.S. 1999. Epidermal lesions on bottlenose dolphins: a product of pollution or the natural environment? European Research on Cetaceans 12:123.

Wilson B., Arnold H., Bearzi G., Fortuna C.M., Gaspar R., Ingram S., Liret C., Pribanic S., Read A.J., Ridoux V., Schneider K., Urian K.W., Wells R.S., Wood C., Thompson P.M., Hammond P.S. 1999. Epidermal diseases in bottlenose dolphins: Impacts of natural and anthropogenic factors. Proceedings Royal Society London B - Biological Sciences 266:1077-1083.

Barbieri G., Bearzi G. 2000. Behaviour of a solitary, "sociable" bottlenose dolphin in southern Italy. European Research on Cetaceans 14:107-109.

Bearzi G., Ferretti S. 2000. Rare report of a bottlenose dolphin foraging in the Venice Lagoon, Italy. European Research on Cetaceans 14:110-114.

Bearzi G., Politi E., Fortuna C.M., Mel L., Notarbartolo di Sciara G. 2000. An overview of cetacean sighting data from the northern Adriatic Sea: 1987-1999. European Research on Cetaceans 14:356-361.

Bearzi G., Reeves R.R., Notarbartolo di Sciara G., Politi E., Canadas A., Frantzis A., Mussi B. 2003. Ecology, status and conservation of short-beaked common dolphins (Delphinus delphis) in the Mediterranean Sea. Mammal Review 33(3):224-252.

Bearzi G., Holcer D., Notarbartolo di Sciara G. 2004. The role of historical dolphin takes and habitat degradation in shaping the present status of northern Adriatic cetaceans. Aquatic Conservation: Marine and Freshwater Ecosystems 14:363-379.

Bearzi G., Bruno S., Politi E., Costa M., Gramolini R., Pierantonio N., Bastianini M. 2005. Distribuzione del tursiope in Adriatico settentrionale in rapporto alle caratteristiche geografiche e batimetriche del bacino: primi risultati. 36th Conference of the Italian Society for Marine Biology (SIBM), Trieste, Italy, 9-13 May 2005.

Bearzi G., Politi E., Azzellino A., Costa M., Pierantonio N., Bastianini M. 2006. Distribuzione del tursiope in rapporto alle caratteristiche del bacino. Workshop intermedio progetto INTERREG III Italia-Slovenia per l’Adriatico Settentrionale. 31 gennaio 2006. ISMAR Venezia.

Bearzi G., Politi E., Costa M., Azzellino A., Bastianini M. 2006. Dolphins in the northern Adriatic Sea: historical data and present occurrence. Conference “Cetaceans, sea turtles and sharks of the Adriatic Sea”, 26– 28 October 2006, Cattolica, Italy.

Bearzi G., Politi E., Azzellino A., Costa M., Bastianini M. 2007. Delfini dell’Adriatico settentrionale: dati storici e presenza attuale. Conference “L’Alto Adriatico: il mare unisce i paesi che separa”, 12-13 April 2007, Venice, Italy.

Bearzi G., Azzellino A., Politi E., Costa M., Bastianini M. 2008. Influence of seasonal forcing on habitat use by bottlenose dolphins Tursiops truncatus in the northern Adriatic Sea. Ocean Science Journal 43(4):175-182.

Bearzi G., Fortuna C.M., Reeves R.R. 2008. Ecology and conservation of common bottlenose dolphins Tursiops truncatus in the Mediterranean Sea. Mammal Review 39(2):92-123.

Pino d'Astore P., Bearzi G., Bonizzoni S. 2008. Cetacean strandings in the Province of Brindisi, Italy, southern Adriatic Sea. Annales, Series Historia Naturalis 18(1):29-38.

Bearzi G., Costa M., Politi E., Agazzi S., Pierantonio N., Tonini D., Bastianini M. 2009. Cetacean records and encounter rates in the northern Adriatic Sea during the years 1988-2007. Annales, Series Historia Naturalis 19(2):145-150.

Bearzi G., Pierantonio N., Bonizzoni S., Notarbartolo di Sciara G., Demma M. 2010. Perception of a cetacean mass stranding in Italy: the emergence of compassion. Aquatic Conservation: Marine and Freshwater Ecosystems 20:644-654.

Bearzi G., Pierantonio N., Affronte M., Holcer D., Maio N., Notarbartolo di Sciara G. 2011. Overview of sperm whale Physeter macrocephalus mortality events in the Adriatic Sea, 1555–2009. Mammal Review 41(4):276–293.

Bearzi G., Reeves R.R., Remonato E., Pierantonio N., Airoldi S. 2011. Risso’s dolphin Grampus griseus in the Mediterranean Sea. Mammalian Biology 76:385–400.

Begoña Santos M., Zuur A.F., Bearzi G., Saveliev A., Smeenk C., Pierce G.J. 2011. Long-term trends in strandings of sperm whales in the North and Adriatic Seas. 19th Biennial Conference on the Biology of Marine Mammal, Tampa, FL, 26 November—2 December 2011.

Genov T., Bearzi G. 2012. Dolphins of Slovenia: marine mammals at the end of the Adriatic Sea. Digital photo book. 54 pp.

Genov T., Bearzi G., Bonizzoni S., Tempesta M. 2012. Long-distance movement of a lone short-beaked common dolphin (Delphinus delphis) in the central Mediterranean Sea. Marine Biodiversity Records. doi:10.1017/S1755267211001163. Vol. 5; e9.

Pierantonio N., Bearzi G. 2012. Review of fin whale mortality events (1728–2011) in the Adriatic Sea, with a description of a previously unreported killing. Marine Biodiversity Records 5, e109 doi:10.1017/S1755267212000930

Pierce G., Santos M.B., Zuur A.F., Bearzi G., Saveliev A., Smeenk C. 2014. Long-term trends in strandings of sperm whales in the North and Adriatic Seas. Workshop "Marine Mammals as Indicators of Historical Changes", 28th Annual Conference of the European Cetacean Society. Liège, Belgium, 5–9 April 2014.

Bearzi G., Bonizzoni S. 2018. Interazioni fra delfini e pesca in Adriatico settentrionale. Resoconto tecnico. Consulenza e supporto tecnico-logistico per Università degli Studi di Padova. 26 pp.

Bonizzoni S., Furey N.B., Bearzi G. 2020. Bottlenose dolphins (Tursiops truncatus) in the north-western Adriatic Sea: spatial distribution and effects of trawling. Aquatic Conservation: Marine and Freshwater Ecosystems 31:635-650.

Bearzi G., Bonizzoni S., Riley M.A., Santostasi N.L. 2020. Bottlenose dolphins in the north-western Adriatic Sea: abundance and management implications. Aquatic Conservation: Marine and Freshwater Ecosystems 31:651-664.

 
 
Field station
 

From 2017 we rely on a field station situated in Loreo (RO), Veneto, Italy.

This base, together with our central base in Cordenons (PN), Friuli Venezia Giulia, Italy, allows to conduct surveys encompassing a vast sector of sea.

 
 
Boats
 

Sea Pro 196 cc — since 2018

 
 

Novamarine RH 580 — between 2010 and 2019

 
 
All photos in this site @ Dolphin Biology and Conservation