Proceedings of the Second Mediterranean Symposium on Marine

CONTRIBUTION TO THE KNOWLEDGE OF THE BENTHIC MARINE
MACROALGAE FROM MANI REGION (MESSINIAKOS GULF, GREECE)
Anastasia TSIRIKA, Dimitris PATOUCHEAS & Sawas HARITONIDIS
Aristotle University <strong>of</strong> Thessaloniki, Department <strong>of</strong> Biology, Institute <strong>of</strong> Botany, GR- 541 24, Thessaloniki, GREECE
ABSTRACT
Limited information is available on <strong>the</strong> benthic marine flora <strong>of</strong> Peloponnese and no data
are provided for <strong>the</strong> Southwestern part <strong>of</strong> Mani region (Messiniakos Gulf). The current
study, including certain biotopes <strong>of</strong> <strong>the</strong> Mani region (Hotassia, Oitilo and Aeropolis), aims
at a broader contribution to <strong>the</strong> survey <strong>of</strong> <strong>the</strong> Greek marine flora. All sample collections
were accomplished with SCUBA-diving during <strong>the</strong> spring and autumn <strong>of</strong> 2002 and 2003.
The studied sites are characterized by <strong>the</strong> intense presence <strong>of</strong> hard substrate from 0m
down to 50m depth, with <strong>the</strong> exception <strong>of</strong> few sandy coasts. Samples were collected
from 0-2m and 35-40m depth. In total, <strong>the</strong> samples contained 147 taxa. From <strong>the</strong>
identified species, <strong>the</strong> red algae dominate qualitatively with 99 representatives, whereas
<strong>the</strong> phaeophyceae and green algae participate with 28 and 20 representatives,
respectively. The Cystoseira spp. communities constitute a source <strong>of</strong> floristic richness on
hard substrate, form a productive belt that plays an important ecological role and shape
most <strong>of</strong> <strong>the</strong> rocky underwater landscape in <strong>the</strong> <strong>Mediterranean</strong> Sea. Concerning <strong>the</strong> depth
<strong>of</strong> 0-2m, significant was <strong>the</strong> presence <strong>of</strong> <strong>the</strong> photophilus association <strong>of</strong> Cystoseira
amentacea and <strong>the</strong> photophilus association <strong>of</strong> Cystoseira compressa accompanied by
Cystoseira barbatula and Chondrophycus papillosus. Moreover, at <strong>the</strong> lower midlittoral
and upper sublittoral zone <strong>the</strong> red alga Tenarea tortuosa covered extended areas. At <strong>the</strong>
depth <strong>of</strong> 35-40m <strong>the</strong> association <strong>of</strong> Cystoseira spinosa and <strong>the</strong> association <strong>of</strong> Cystoseira
foeniculacea f. schiffneri were recorded. At that depth very important was <strong>the</strong> presence
<strong>of</strong> <strong>the</strong> brown alga Sargassum acinarium accompanied by dense populations <strong>of</strong> <strong>the</strong>
epiphytic and epilithic Callithamnion granulatum. All over <strong>the</strong> substrate at 35-40m depth
dense turfs <strong>of</strong> <strong>the</strong> filamentous red macroalga Womersleyella setacea occurred. This
species, described originally from <strong>the</strong> Hawaiian Islands and later reported from o<strong>the</strong>r
tropical localities, has recently become widespread in <strong>the</strong> <strong>Mediterranean</strong> Sea. In Greece,
it has been observed at North and South Aegean Sea. No sporangia or sexual
reproductive structures were observed at <strong>the</strong> specimens <strong>of</strong> <strong>the</strong> studied site. Ano<strong>the</strong>r pantropical
to temperate-warm water species that is currently experiencing a dramatic and
continuous spread throughout most <strong>of</strong> <strong>the</strong> <strong>Mediterranean</strong> Sea was recorded at <strong>the</strong>
studied sites. The green alga Caulerpa racemosa occurred at 0-2m, as well as at 35-40m
depth, expanding on rocky substrate, benthic fauna, encrusting algae as Corallinaceae
and Peyssonnelia spp., turf species and erect algae. The species expansion was much
more significant at deep water than at shallow water biocommunities. Specimens <strong>of</strong>
Caulerpa racemosa from Mani region possessed uncrowded radial to distichous
branchlets and <strong>the</strong> branchlets shape was clavate with rounded apex. The morphology <strong>of</strong>
<strong>the</strong> specimens indicates that <strong>the</strong>y belong to <strong>the</strong> invasive variety Caulerpa racemosa var.
occidentalis. The species Laurencia chondrioides and Osmundea pelagosae are
recorded for <strong>the</strong> first time at <strong>the</strong> Greek coasts in <strong>the</strong> present study. Both species were
found to grow as epiphytes at <strong>the</strong> depth <strong>of</strong> 35-40m.
ACTES DU DEUXIEME SYMPOSIUM MEDITERRANEEN SUR LA VEGETATION MARINE (ATHENES, 12-13 DECEMBRE 2003)
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