Proceedings of the Second Mediterranean Symposium on Marine

PROCEEDINGS OF THE SECOND MEDITERRANEAN SYMPOSIUM ON MARINE VEGETATION (ATHENS, 12-13 DECEMBER 2003)
154
CYSTOSEIRA SPP. ASSOCIATIONS IN THE NORTH-EASTERN
MEDITERRANEAN: THE CASE OF EVOIKOS GULF
(CENTRAL AEGEAN SEA, GREECE)
Ioanna VARKITZI 1 , Panayotis PANAYOTIDIS 1 and Barbara MONTESANTO 2
1 Hellenic Centre for Marine Research, Institute <strong>of</strong> Oceanography, POB 712, Anavissos 19013, Greece
2 A<strong>the</strong>ns University, Section <strong>of</strong> Ecology & Taxonomy, Panepistiomiopolis 15784, A<strong>the</strong>ns, Greece
Ioanna Varkitzi: e-mail address: ioanna@ath.hcmr.gr
ABSTRACT
The species composition <strong>of</strong> <strong>the</strong> Cystoseira associations was studied on a gradient <strong>of</strong>
decreasing wave energy (from <strong>the</strong> exposed sou<strong>the</strong>rn part <strong>of</strong> <strong>the</strong> gulf to <strong>the</strong> sheltered
nor<strong>the</strong>rn part). Samplings were carried out at four sites <strong>of</strong> <strong>the</strong> Greek NATURA 2000
network. Phytosociological analysis and statistical treatment grouped toge<strong>the</strong>r <strong>the</strong> two
sites at <strong>the</strong> exposed and transitional part <strong>of</strong> <strong>the</strong> gulf. In <strong>the</strong>se sites <strong>the</strong> dominant species
was Cystoseira crinitophylla and this association corresponded to Cystoseiretum crinitae
Molinier 1958. The two sheltered sites formed two distinct groups. The dominant species
was Cystoseira foeniculacea f. tenuiramosa but <strong>the</strong> accompanying species were
different. Despite <strong>the</strong> absence <strong>of</strong> C. sauvageauana, <strong>the</strong> accompanying species make
<strong>the</strong>se two aspects similar to Cystoseiretum sauvageauanae Giaccone 1994. However,
<strong>the</strong>y do not correspond clearly to any <strong>of</strong> <strong>the</strong> Cystoseira associations described so far.
Therefore, <strong>the</strong>y could indicate a new type <strong>of</strong> Cystoseiretum sauvageauanae or even a
new association.
KEYWORDS: Cystoseira, NATURA 2000, <strong>Mediterranean</strong>, Aegean
INTRODUCTION
The genus Cystoseira C. Agardh (Fucales, Phaeophyceae) is part <strong>of</strong> <strong>the</strong> biological identity
<strong>of</strong> <strong>the</strong> <strong>Mediterranean</strong> Sea (Roberts, 1978). Cystoseira species are <strong>the</strong> dominant element
<strong>of</strong> <strong>the</strong> photophilic algal associations on undisturbed hard substrates <strong>of</strong> <strong>the</strong> upper
infralittoral zone (Margalef, 1985). Many studies have dealt with <strong>the</strong> photophilic Cystoseira
associations <strong>of</strong> <strong>the</strong> W Meditarranean so far (Feldmann, 1937; Molinier, 1960; Giaccone,
1968; Boudouresque, 1969; Verlaque, 1988; Ballesteros, 1990b; Giaccone and Bruni,
1973; Cormaci et al., 1992; Rodriguez and Polo, 1996). In <strong>the</strong> Eastern <strong>Mediterranean</strong>,
Huvé (1972) first studied <strong>the</strong> distribution and ecology <strong>of</strong> <strong>the</strong> Cystoseira species in <strong>the</strong>
Aegean Sea. Following researches added more information about <strong>the</strong> phytosociology,
phytogeography and ecology <strong>of</strong> <strong>the</strong> Cystoseira species in <strong>the</strong> Greek coastal areas
(Haritonidis, 1978; Athanassiadis, 1987; Montesanto and Panayotidis, 2000).
Pérès and Picard, (1964) suggested that <strong>the</strong> algal associations <strong>of</strong> <strong>the</strong> genus Cystoseira
should be considered as <strong>the</strong> final stage (climax stage) in <strong>the</strong> ecological succession <strong>of</strong> <strong>the</strong>
photophilic algal associations in <strong>the</strong> <strong>Mediterranean</strong>. Striking differences have been found by