The Mediterranean bottlenose dolphin
Common bottlenose dolphins Tursiops truncatus. Photo © Tethys Research Institute.
Bottlenose dolphins are among of the best-known cetaceans worldwide. In the Mediterranean Sea, however, modern cetacean field studies did not start until the late 1980s. Bottlenose dolphins have been studied only in relatively small portions of the basin, and wide areas remain largely unexplored. Research and monitoring of population abundance and status must therefore play a major role in filling the gaps in knowledge.
Whilst intentional killing was likely the most important cause of mortality until the 1960s, important ongoing threats include incidental mortality in fishing gear and the reduced availability of key prey caused by region-wide overfishing and environmental degradation.
Additional potential or likely threats include the toxic effects of xenobiotic chemicals, epizootic outbreaks, direct disturbance from boating and shipping, noise, and the consequences of climate change.
The flexible social organization and opportunistic diet and behaviour of bottlenose dolphins may allow them to withstand at least some of the effects of overfishing and habitat degradation. However, dolphin abundance is thought to have declined considerably in the region (*) and appropriate management measures are needed to prevent further decline.
Management measures that could benefit bottlenose dolphins, involving sustainable fishing, curbing marine pollution and protecting biodiversity, are already embedded in much existing legislation and a large number of treaties. Compliance with those existing commitments and obligations represents the highest management priority.
For more information on Mediterranean bottlenose dolphins see:
Bearzi G., Fortuna C.M. 2006. Common bottlenose dolphin Tursiops truncatus (Mediterranean subpopulation). Pp. 64-73 in Reeves R.R., Notarbartolo di Sciara G. (compilers and editors). The status and distribution of cetaceans in the Black Sea and Mediterranean Sea. IUCN Centre for Mediterranean Cooperation, Malaga, Spain. (whole report: 2,752 Kb)