Preprint volume - SIBM

Pre-print Volume - Posters
MANAGEMENT OF THE COASTAL ZONE COMMITEE
S. BUSSOTTI, P. GUIDETTI
Lab. di Zoologia e Biologia Marina, DiSTeBA, Univ. del Salento, Via Prov.le Lecce-Monteroni - 73100 Lecce,
Italia.
simona.bussotti@unisalento.it
FISH FAUNA OF MARINE CAVES
IN FOUR ITALIAN MARINE PROTECTED AREAS
FAUNA ITTICA DI GROTTA
IN QUATTRO AREE MARINE PROTETTE ITALIANE
Abstract – In this study the fish fauna associated with submerged caves was investigated using visual
census in 14 marine caves located within 4 Marine Protected Areas. Species richness varied between 21
and 5 species within each cave, which could reflect the non negligible variability among the investigated
caves in terms e.g. of morphology, length and presence/absence of light in the innermost portions. This
study stresses that fish assemblages hosted inside marine caves are fairly variable, but they often contribute
to increase local diversity.
Key-words: fish fauna, caves, biodiversity, marine parks, Mediterranean Sea.
Introduction - Marine caves are among the few marine habitats protected by the
European Community (Habitat Directive 92/43EEC) due their uniqueness and fragility
(see Cicogna et al., 2003; Bussotti et al., 2006; Parravicini et al., 2010). Mediterranean
marine caves host several fish species (e.g. Abel, 1959; Riedl, 1966; Bussotti &
Guidetti, 2009) that include both cryptic and shy species typical of caves, and species
that are also associated with rocky reefs outside. This study aims at evaluating 1) the
variability in fish species richness in 14 marine caves at 4 Italian Marine Protected
Areas (MPAs) and 2) the contribution of such environments to local fish diversity.
Materials and methods - Fish sampling was carried in September-October 2009 in 14
submerged caves at 4 MPAs: Capo Caccia (SS), 6 caves (between ~5 and 18 m depth);
Lampedusa (AG), 2 caves (~10-19 m depth); Plemmirio (SR), 4 caves (~18-30 m
depth); Porto Cesareo (LE), 2 caves (~8-10 m depth). The investigated caves were
blind or with several openings and varied remarkably in terms of morphology and
length, presence/absence of the ceiling and characteristics of the bottom (e.g. rocky vs
muddy). Fish abundances and size were estimated using a modified transect visual
census method (Bussotti & Guidetti, 2009): transects were 10 to 35 m long (in relation
to shape and morphological discontinuities of each cave, like walls, ceiling, bottom)
and 2 m wide.
Results and conclusions - A total of 37 species was recorded considering all 14
investigated caves: 27 species at Capo Caccia, 18 at Porto Cesareo, 16 at Plemmirio
and 15 at Lampedusa. The highest number of species (n=21) was found inside the
Nereo cave at Capo Caccia MPA and the lowest number (n=5) at Plemmirio MPA
inside the Mazzare cave (Fig. 1). A higher number of species was usually associated to
cave walls compared to ceilings or bottoms. The complete darkness in the innermost
cave portions was a condition necessary but not sufficient to host the strictly
speleophilic fish Grammonus ater. Apogon imberbis was found in all caves. The
speleophilic gobids Corcyrogobius lichtensteini and Thorogobius ephippiatus were
41 st S.I.B.M. CONGRESS Rapallo (GE), 7-11 June 2010
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