Dolphins, Whales and Porpoises: 2002-2010 Conservation - IUCN

Figure 33. Common bottlenose dolphins – mother and calf – race along the surface near the coast of the
Greek island of Kalamos in the eastern Ionian Sea. Photo: Tethys Research Institute/Sebastiano Bruno.
49. Develop and test approaches to reducing conflicts
between bottlenose dolphins and smallscale
fisheries in the Mediterranean Sea
There is a long history of interactions between bottlenose
dolphins and coastal, small-scale commercial fisheries in
the Mediterranean Sea. In recent years, issues related to
perceived competition and direct conflict between dolphins
and fisheries have become major concerns. A workshop
sponsored by Italy’s Institute for Applied Marine Research
was held in Rome in May 2001 to investigate and evaluate
efforts by fishermen and others to deter dolphins from nets
(Reeves et al. 2001a). It was concluded that although the
problem of dolphin depredation has become a major issue in
the eyes of Mediterranean fishermen (and therefore deserves
to be addressed in a responsible manner by government
agencies and conservation groups), there is a danger
that the ad hoc and even experimental use of noise-making
deterrence devices could have unintended adverse effects on
other species (e.g., Critically Endangered Mediterranean
monk seals, Monachus monachus). Such devices may also
prove ineffective for reducing fishery-dolphin conflicts.
The workshop produced a series of recommendations for research
and development, and concluded that high-intensity
acoustic devices that are typically used to keep pinnipeds
away from aquaculture facilities are inappropriate for use in
alleviating conflicts between dolphins and fisheries in the
Mediterranean.
This project consists of implementing the recommendations
made by the Rome workshop. As an initial step, it is
necessary to obtain detailed quantitative information on the
characteristics of bottlenose dolphin populations in the
Mediterranean (Project 48) and on the spatial, seasonal, and
operational features of small-scale coastal trammel and gillnet
fisheries in the region. Identification of hotspots where
overlap occurs (i.e., high dolphin densities matched with
high levels of fishing activity) should be followed by rigorous
site-specific studies to characterize and quantify the
costs of dolphin depredation. Where serious problems are
found to exist, rigorous tests of potential solutions should be
conducted after extensive consultations with fishermen as
well as technical experts. It is important that due consideration
be given to the real or potential adverse side effects
of any mitigation approach. The workshop concluded that
non-acoustic means of reducing conflicts, such as changes
in methods of gear deployment or the use of quieter engines,
hold promise and deserve to be evaluated.
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