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

Protected Areas and Mediterranean Biodiversity, and the
CMS agreement on conservation of Mediterranean and
Black Sea cetaceans mentioned in earlier chapters), little
progress has been made toward understanding the causes of
the short-beaked common dolphin’s regional decline; and
no concrete measures have been taken to arrest and reverse
this trend.
Contamination by xenobiotics, such as PCBs, and a decrease
in prey quality or availability have been implicated in
the common dolphin’s regional decline (Bearzi 2001; Politi
and Bearzi in press; Fossi et al. in press). Indeed, it is
possible that these factors have been acting synergistically,
with the poor nutritional status of individuals prompting the
mobilization of lipophilic contaminants that would otherwise
be “stored” in their blubber. However, the relative
importance of these and other factors is not understood, and
it is therefore difficult to design and implement mitigation
measures. Bycatch and intentional killing may have had an
impact in some areas (e.g., Silvani et al. 1999), but these
factors do not seem to have played a significant role in some
of the Mediterranean areas where common dolphins have
declined (e.g., in the northern Adriatic Sea)(Bearzi and
Notarbartolo di Sciara 1995; Bearzi et al. 2001). Although
the Mediterranean Sea represents less than 1% of the
planet’s water surface area, it hosts 15% of all commercial
traffic and 30% of all hydrocarbon ship commerce. The
impacts of overfishing and chemical pollution in the
Mediterranean are extensive and relatively well document-
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ed (e.g., Stanners and Bourdeau 1995; FAO 1997; EAA/
UNEP 2000).
Remaining issues: No specific management measures
have been taken to protect the few remaining groups of
common dolphins in the central and eastern Mediterranean
even though it is well known that they are exposed to direct
disturbance by vessel traffic, bycatch in fishing gear, and
habitat degradation (e.g., chemical pollution, possibly prey
depletion). Although the lack of scientific information is a
serious problem in attempting to pinpoint and address specific
threats, it does not justify continued inaction.
Conservation recommendations: In addition to stressing
the importance of more research (Project 47, Chapter 5), the
CSG recommends that a small number of pilot conservation
and management projects be implemented immediately
in selected areas where relict groups of common
dolphins are known to reside. Two such areas could be
waters adjacent to the island of Kalamos in Greece, and near
the island of Ischia in Italy. Both areas are known to provide
critical habitat for small populations of common dolphins.
The dolphins around Kalamos have declined dramatically
within the past eight years (Politi and Bearzi in press). The
immediate establishment of protected areas should be accompanied
by experimental management plans that include
intensive monitoring of the dolphins, restrictions on vessel
traffic and fishing activity, education efforts directed at the
local fishing communities and recreational users, and
focused research.