1.13 This area offers great potential for the
conservation of a large number of nationally important habitats and
species. Certain species (the European shag, the giant limpet Patella
ferruginea) are present in numbers which provide the nucleus
of genetically stable populations that may be considered source populations
capable of providing the starting point for colonization (natural
or artificial) of potential habitats, to differing degrees, depending
on the manner in which the larvae and individual representatives of
those species are distributed. This area of the Strait of Bonifacio
is thus of vital importance for declining populations or small sub-populations
of species. For example, conservation of the national gene pool of
threatened meta-populations of species such as the giant limpet could
allow it to be reintroduced into areas of the Mediterranean where
it is now extinct.
1.14 The care of this area is also very important
to marine avifauna. This is a major site for the European shag (Phalacrocorax
aristotelis aristotelis) and for sizeable numbers of Cory's
shearwater (Calonectris diomedea). The Strait of Bonifacio
is also a main point for the passage, roosting and feeding of the
Yelkouan shearwater. The whole area is a feeding ground for these
species.
1.15 The European shag population does not exceed
10,000 pairs across the whole of its small area of distribution in
the Mediterranean. The Strait of Bonifacio has high priority in the
conservation of this species. In 2001, the nesting population of the
Strait of Bonifacio represented more than 50 per cent of the French
population and 7 per cent of the world population. The main problems
for this species are disturbance to nesting sites, accidental capture
during small-scale fishing and the disappearance of habitats owing
to the expansion of tourism.
1.16 The nesting population of Cory's shearwater
accounts for 40 per cent of the national nesting total. With 345 pairs,
the Lavezzu island colony is the most numerous in France. This species
is on the decline owing to the introduction of allocthonous species
(dogs, cats and rats), the removal of eggs from certain colonies and
the development of tourism, which disturbs colonies and destroys habitat.
1.17 With around 200 nesting pairs within the
perimeter of the area, the population of the highly unobtrusive storm
petrel (Hydrobates pelagicus) represents around one third
of the French Mediterranean population and between 15 and 18 per cent
of the French population including Atlantic birds. Europe's smallest
marine bird (15 cm) is in steep decline in the Mediterranean, mainly
owing to the introduction of predators such as the black rat (Rattus
rattus). The colonies are now highly localized and concentrated,
making them very vulnerable.