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Fattorini & Dapporto
Revista de Gestão Costeira Integrada / Journal of Integrated Coastal Zone Management 14(2):185-197 (2014)
1. INTRODUCTION
The Mediterranean basin is occupied by almost 12,000
islands and islets (Arnold, 2008). Most of the Mediterranean
islands have an area less than 3 km2; only 162 Mediterranean
islands are more than 10 km2 large, 15 have an area over
500 km2, and 9 present an area over 1000 km2 (Morey &
Martinez, 2000).
Because of the high “perimeter/area” ratio that
characterizes small islands, their environmental diversity
tends to be mostly represented by coastal ecosystems. Thus,
although small islands occupy only a very small fraction of
Earth surface, they may play an important role in conserving
coastal ecosystems. Usually, the smaller the island, the
higher the proportion of coastal valued and/or threatened
ecosystems (Morey & Martinez, 2000). The total area of the
Mediterranean islands is about 13% of the sea area, but they
have a coastal length of 24,622 km, only 15% less than the
mainland coastline.
In an attempt to achieve sustainability of Mediterranean
coastal areas, fourteen Contracting Parties of the Barcelona
Convention signed the Integrated Costal Zone Management
Protocol in 2008, thus recognizing the need for management
policies that are based on a holistic viewpoint of the
functions that makeup the complex and dynamic nature
of interactions in the coastal environment. This Protocol
was then ratified by the European Union in 2010. In 2002,
the European Parliament and the European Council also
adopted a Recommendation on Integrated Coastal Zone
Management which stressed the need to cover “the full
cycle of information collection, planning, decision-making,
management and monitoring of implementation” (http://
ec.europa.eu/environment/iczm/home.htm).
As small islands are largely coastal entities of reduced
surface, they are areas where the problems of sustainability
are exacerbated (see, for example, Saffache & Angelelli,
2010, for a discussion on the Lesser Antilles case) and
present therefore the need for a urgent rethinking about
their management (Dias et al., 2010). Coastal ecosystems
in small islands can be threatened by a number of reasons,
including pollution, coastal land occupation by tourist
installations, concrete structures and networks of roads,
population increase and increase in tourist pressure, resulting species vulnerability and used this information to identify
in a general landscape degradation and biodiversity loss
(Morey & Martinez, 2000). Rising in sea level due to global
warming is another important threat for coastal habitats of
small islands (see Manne 2013 for a general discussion).
With their environment more fragile and vulnerable than
that of continental sites of similar areas, Mediterranean
small islands should be therefore considered as valued
threatened lands, needing special protection (Morey &
Martinez, 2000). In terms of biodiversity, small islands
host exclusive assortments of species, sometimes including
endemic taxa, usually represented by small populations,
which enhance their conservation value (Fattorini, 2006a;
Whittaker & Fernández-Palacios 2007). Thus, for an
integrated management of islands it is essential to know
where biodiversity is concentrated and where it is most
imperilled, in order to prioritise conservation actions and
adopt the most urgent decisions.
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The distribution of small islands in the western and
eastern sectors of the Mediterranean Basin is uneven. In the
Western Mediterranean there are some large islands (the
Balearics, Corsica, Sardinia, Sicily) with relatively few small
islands (usually associated with the largest ones), whereas in
the Eastern Mediterranean there are few large islands but an
extraordinary large number of small islands, especially in the
Adriatic Sea (near the coast of the former Yugoslavia) and in
the Aegean Sea. Placed in the centre of the Mediterranean,
the Italian peninsula is at the interface between the Western
and the Eastern sectors. Thus, some Italian small islands are
placed in the Western Mediterranean, a few other in the
Eastern Mediterranean. Moreover, Italian small islands vary
greatly in their isolation (distance from the mainland and/
or other islands) and geographical position with respect to
major island systems and mainland areas which might act
as source of species: for example, some islands are closer to
the Sardinia-Corsican area and North African coasts than to
the Italian peninsular ones. Thus, although not so numerous
as those forming the Greek archipelagos, the Italian islands
represent a biogeographically very heterogeneous assemblage
of areas in most cases under strong human pressure.
Our knowledge of the biodiversity of Italian small islands
varies considerably among islands and taxa, so only for the
best investigated taxa (such as butterflies, Dennis et al., 2008)
and archipelagos (such as the Tuscan Islands or the circum-
Sicilian islands. Fattorini, 2009a, 2010a) wide comparisons
and cross-taxon biogeographical and conservation analyses
are possible. Among the best sampled taxa for which there
are a large number of well explored islands, the beetles
belonging to the family Tenebrionidae are particularly
interesting for the conservation of coastal ecosystems
because they represent a conspicuous component of the
beetle fauna inhabiting Mediterranean coastal ecosystems in
terms of species richness, individual abundance and biomass
(Fattorini, 2008a; Fattorini et al., 2012a and references
therein).
Taking advantage of a series of previous researches
(Fattorini, 2006a, 2008a, 2009a,b, 2011a; Fattorini &
Fowles, 2005) we were able to obtain virtually complete
tenebrionid species lists for most of the Italian small islands
and to use these data in the present paper to investigate
conservation priorities. For this, we evaluated tenebrionid
the islands that host the most imperilled tenebrionid
communities.
2. MATERIAL AND METHODS
We collected presence data on tenebrionid species for 57
Italian small islands (Figure 1). These data were obtained
from literature sources (reviewed in Fattorini, 2008, plus
data provided in Fattorini, 2009a,b, 2010a, 2011a,b) and
personal new records.
Study islands varied greatly for their size and distance
from the mainland. Island geographical characteristics are
given in Table 1 whereas their conservation status is given in
Table 2. Island area varied from 0.0000249 km2 (a very small
islet in the Tuscan Archipelago) to 223.5 km2 (Elba Island)
(mean ± SD: 12.185 ± 32.669). Distance to the mainland
varied from 0 km (Mount Argentario, a fossil island currently
connected to the mainland by three narrow strips of land) to