ecological effects of marine protected areas empafish project ...

EMPAFISH Booklet no. 1 Ecological effects of Atlanto-Mediterranean MPAs in the EU
Ustica Island: ecological studies
� General
o Fish assemblage
Some circumstantial information on the fish fauna of the Ustica island prior to
protection is available in De Cristofaro (1970). In this report a total of 75 fish
species were listed.
Fish assemblage structure has been studied only after the effective
enforcement of the reserve. Structure and composition of coastal fish
assemblages were investigated by underwater visual census (UVC) and
experimental trammel nets (Arculeo et al. 1994, 1996; Vacchi et al. 1998; La
Mesa & Vacchi 1999; Palmeri 2004). Most studies focused on the nektobenthic
fish fauna associated to the photophilic rocky infralittoral (Vacchi et al.
1998; La Mesa & Vacchi 1999), although patchy information on other habitats
(e.g. barrens and seagrass meadows) are also available along the island
coasts (Arculeo et al. 1994, 1996; Palmeri 2004). Overall 102 species were
recorded, representing the 19.2% of the whole Mediterranean Basin (Riggio &
Milazzo 2004). Among these 20 cryptobenthic species belonging to Blenniidae,
Gobiidae, Tripterygiidae, Scorpaenidae and Gobiesocidae were recorded.
Species composition, diversity and relative density of these cryptic species
were also investigated in relation to habitat macro- and micro- characteristics
(La Mesa et al. 2006), and a similar approach was used to assess microhabitat
requirements of juvenile dusky grouper (Epinephelus marginatus) (La Mesa et
al. 2002). Habitat selection and habitat use of two coastal species
(Thalassoma pavo and Chromis chromis) was also investigated (Badalamenti
2004).
Findings worth mentioning for biogeographical and ecological reasons are the
constant and increasing presence of some subtropical fish species mainly of
Atlantic origin – such as Sphyraena viridensis, Sparisoma cretense, Scorpaena
maderensis, Thorogobius ephippiatus, Gobius vittatus and Caranx crysos
(Vacchi et al. 1999) – although such information can be generally extended to
the whole Southwestern Mediterranean region.
o Benthic communities
Riggio & Milazzo (2004) reviewed the major results of the scientific research
carried out in the Ustica Island coastal waters (within 50 m depth) during the
latest 30 years. The list of taxa censused showed that local species richness
exceeds the values expected on account of the coastal perimeter and bottom
area of the island. Benthic biodiversity described was on average 24.8% of the
total Mediterranean Sea. This is definitely an underestimation since not all the
habitats have been investigated in the Ustica waters.
Phytobenthos (rodophytes, chlorophytes, pheophytes and phanerogams) with
450 species represents 33% of the Mediterranean marine flora (Giaccone
1967, 1968, 1983; Giaccone et al. 1985; Buia et al. 1999; Furnari et al. 2003
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