Preprint volume - SIBM
Preprint volume - SIBM
Preprint volume - SIBM
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Pre-print Volume - Oral presentations<br />
Topic 2: MARINE ORGANISMS AND ECOSYSTEMS AS MODEL SYSTEMS<br />
M. BO, C.G. DI CAMILLO, M. BERTOLINO, P. POVERO 1 , C. MISIC 1 , M. CASTELLANO 1 ,<br />
A. COVAZZI HARRIAGUE 1 , G.P. GASPARINI 2 , M. BORGHINI 2 , K. SCHROEDER 2 ,<br />
G. BAVESTRELLO<br />
1 DisMar, Università Politecnica delle Marche - 60131 Ancona, Italia.<br />
m.bo@univpm.it<br />
2 DipTeRis, Università degli Studi di Genova - 16132 Genova, Italia.<br />
3 CNR-ISMAR - 19036 La Spezia, Italia.<br />
THE MEGABENTHIC ASSEMBLAGES OF THE VERCELLI SEAMOUNT<br />
(NORTH TYRRHENIAN SEA)<br />
LE COMUNITÀ MEGABENTONICHE DEL VERCELLI SEAMOUNT<br />
(MAR TIRRENO SETTENTRIONALE)<br />
Abstract - The megabenthic assemblages of the Vercelli Seamount (North Tyrrhenian Sea) were studied<br />
through ROV imaging from 60 to 500 m depth and a peculiar benthos zonation was observed. The<br />
shallower rocky peak (60-100 m depth) hosted a very reach coralligenous community characterized, on the<br />
top by the kelp Laminaria rodriguezii, by gorgonian assemblages on the southern flank and by sponges-soft<br />
corals assemblages on the northern one. On the detritic bottom at the base of the peak, a very dense<br />
population of the crinoid Leptometra phalangium was observed. On the edge of the detritic plain, around<br />
180-200 m depth, a ring of the yellow scleractinian coral Dendrophyllia cornigera, mainly dead, was<br />
recorded. The rocky slopes from 200 to 500 m depth, covered by a thick iron-manganese crust, were very<br />
poorly colonized, mainly by encrusting sponges and serpulids. This research is the first detailed<br />
investigation, through ROV imaging, of megabenthic communities living on a Mediterranean seamount,<br />
representing therefore a study model for this peculiar ecosystem.<br />
Key-words: benthos, seamounts, Tyrrhenian Sea, ROV imaging.<br />
Introduction - Seamounts are considered to be hotspots of marine biodiversity being<br />
characterised by rich benthic suspension-feeding communities of hard substrates<br />
mainly composed of sponges, hydrozoans, scleractinians, antipatharians and<br />
gorgonians providing habitat for numerous smaller, mobile invertebrates and hosting<br />
an abundant and diversified ichthyofauna (e.g. Samadi et al., 2007). The Mediterranean<br />
seamounts have been relatively well investigated from the geological point of view<br />
(e.g. Zhuleva, 1988), but few data are available concerning the composition of their<br />
megabenthic assemblages. An example is the description of a rich algal community and<br />
the mollusc fauna on the top of the Amendolara Bank in the Ionian Sea by dredging<br />
program (from 20 m depth) (Cecere & Perrone, 1988). Also the benthic fauna of the<br />
top of the Eratosthenes Seamount (750 m depth) was studied by trawl and grab, to the<br />
south of Cyprus, in the Eastern Mediterranean Sea (Galil & Zibrowius, 1998). Recently<br />
ROV surveys were used to describe the coralligenous assemblages from 80 to 170 m<br />
depth on four seamounts along the Spanish coast (Aguiliar et al., 2009). Moreover, the<br />
biodiversity of several banks and shoals has been investigated along the continental<br />
shelf of the North Tyrrhenian Sea, Sicily Strait, and the Aegean Sea. Studies focusing<br />
on deep coral assemblages were made on some rocky shoals along the Calabrian<br />
mesophotic zone (Bo et al., 2009) and on the white coral reefs found in the Ionian Sea<br />
and mainly composed by the scleractinians Lophelia pertusa and Madrepora oculata.<br />
The Tyrrhenian bathyal plain is spotted by at least 14 large and intermediate<br />
seamounts. Their peaks are generally several hundred metres beneath the surface of the<br />
sea, Vercelli Seamount however, together with Strabo Seamount, are shallow<br />
41 st S.I.B.M. CONGRESS Rapallo (GE), 7-11 June 2010<br />
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