Preprint volume - SIBM
Preprint volume - SIBM
Preprint volume - SIBM
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
Pre-print Volume - Oral presentations<br />
Topic 1: BIODIVERSITY AND CONSERVATION SCIENCE: CONTRIBUTING TO MANAGEMENT<br />
an area of 400 cm 2 (Bianchi et al., 2003). For each of the 16 samples (more 16<br />
replicates), the main macroalgal taxa were identified; Molluscs (Poliplacophora,<br />
Gasteropoda and Bivalvia), Polychaetes and Decapods were identified at specific level<br />
(Bianchi et al., 2003). The quantitative and qualitative results as well as the<br />
environmental factors, like seasonal hydrodynamism, wind exposition and substratum,<br />
were analyzed through Cluster Analysis, n-MDS Analysis, and Symper Analysis using<br />
Primer v6 β. The biodiversity level was assessed by means of Shannon-Weaver Index.<br />
As regard Posidonia oceanica beds, shoots density in upper, middle, and lower zones,<br />
maximum depth and type of the lower limit were analyzed (Buia et al., 2003). In<br />
addition, a Pinna nobilis population, present in upper zone of the southern meadow,<br />
was studied in detail; for each specimen, settlement depth was noted down, maximum<br />
width and length of the bigger valve were measured.<br />
Results – The northern coast is in front of the open sea and exposed to winter winds<br />
action (high hydrodynamism area); the southern coast is located inside the Viticcio<br />
Gulf and sheltered from these winds (low hydrodynamism area). Photophilic algae<br />
community is typical of mesolittoral and upper infralittoral hard substrata: Cystoseira<br />
spp., Padina pavonica, Stypocaulum scoparium, Rissoella verrucolosa, Acetabularia<br />
spp. are the main observed taxa. In N area 2591 specimens, belonging to 98 species (37<br />
Molluscs, 49 Polychaetes, and 12 Decapods), were identified compared to the 2201<br />
ones, belonging to 157 species (63 Molluscs, 73 Polychaetes and 21 Decapods), in S<br />
area. Thirty-eight species characterized N area, 93 species the S one; 64 species are<br />
common to both areas. In the southern part of the istmus, species typical of high<br />
hydrodynamic conditions, such as the Polychaetes Syllis armillaris and Perinereis<br />
cultrifera (Bellan, 1969), were found.<br />
In the two sites, Polychaetes are the richest taxon as regard the number both of species<br />
and specimens; a conspicuous quali-quantitative increase of this taxon is evident in<br />
September, more pronounced in respect to the other taxa.<br />
The total biodiversity level is high in all the stations: Shannon-Weaver Index shows<br />
noticeable values, especially as regard the samples relevant to the S area (Fig. 2).<br />
Fig. 2 - Shannon-Weaver Index. N area samples (sample and replicate), in black, S area samples (in<br />
grey).<br />
Indice di Shannon-Weaver per i campionamenti (campione e replica) nell’area N (in nero) e<br />
nell’area S (in grigio).<br />
41 st S.I.B.M. CONGRESS Rapallo (GE), 7-11 June 2010<br />
63<br />
Legend<br />
RE = rocky bottom, E side, N area<br />
SE = rocky bottom, E side, S area<br />
RW = rocky bottom, W side, N<br />
area<br />
SW = rocky bottom, W side, S<br />
area<br />
BN = quay, N side, N area<br />
ME = mole, E side, S area<br />
BW = quay, W side, N area<br />
MW = mole, W side, S area<br />
-M = samples of May<br />
-S = samples of September