Preprint volume - SIBM
Preprint volume - SIBM
Preprint volume - SIBM
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Pre-print Volume - Posters<br />
BENTHOS COMMITEE<br />
The most abundant macroalgae species were the Phaeophyceae Ascocyclus orbicularis<br />
(J. Agardh) Kjelman and Sphacelaria sp., the Rhodophyta Acrothamnion preissii<br />
(Sonder) E.M. Wollaston and Gayliella flaccida (Harvey ex Kutzing) T.O. Cho & L.J.<br />
McIvor; the most abundant species among the fauna were the Hydrozoa Plumularia<br />
obliqua (Johnston, 1847), the Bryozoa Electra posidoniae (Gautier, 1957),<br />
Fenestrulina malusii (Audouin, 1826) and Tubulipora flabellaris (O. Fabricius, 1780)<br />
and the Foraminifera .<br />
Concerning the red encrusting algae, it was very difficult to define the percentage<br />
cover of each present species (Hydrolithon boreale (Foslie) Y.M. Chamberlain,<br />
Hydrolithon cruciatum (Bressan) Y.M. Chamberlain, Hydrolithon farinosum (J.V.<br />
Lamouroux) D. Penrose & Y.M. Chamberlain, Pneophyllum fragile (Kutzing, 1843),<br />
so we defined one group (Hydrolithon- Pneophyllum spp.) which included all species<br />
of both genera (Giovannetti et al., 2006).<br />
The results showed that the macroalgal epiphytic assemblage (specific percentage<br />
cover) is more developed on transplanted shoots than on natural shoots; the result was<br />
opposite for the animal epiphytic assemblage. Concerning the epiphytic assemblage in<br />
its totality, the results highlighted that the specific richness was more abundant on<br />
transplanted shoots.<br />
ANOVA analysis showed a significant difference between natural and transplanted<br />
shoots only for Foraminifera and Electra posidoniae.<br />
PERMANOVA analysis showed a significant difference among natural and<br />
transplanted shoots and the nMDS ordination of epiphytic assemblage showed 2<br />
separate groups.<br />
Conclusions – The results illustrated a possible difference in the structure of<br />
assemblages of P. oceanica epiphytes between natural and transplanted shoots.<br />
However, it is necessary to highlight the different shoot density in the two studied<br />
conditions. Competition for light plays an important role in structuring marine<br />
communities and there is circumstantial evidence to indicate that light is a primary<br />
factor influencing algal recruitment and growth (Trautman & Borowitzka, 1999): it is<br />
likely that the reduced shoot density of artificial meadow (20 shoots/m 2 ) has permitted<br />
a higher irradiation on the transplanted shoots, which may have influenced the<br />
epiphytic algal community’s abundance and composition.<br />
The results obtained suggest that future studies aimed at detecting epiphytic<br />
community’s difference between natural and transplanted shoots should specifically be<br />
focused on density shoots and seasonality of sampling.<br />
References<br />
ANDERSON M.J. (2001) - A new method for a non-parametric multivariate analysis of variance.<br />
Aust. Ecol., 26: 32-46.<br />
CINELLI F.L., BOCCALARO F., CINELLI F., BURGASSI M., PIAZZI L., RENDE F., ZANELLA<br />
M. (2007) - Utilizzo sperimentale in mare di sistemi tecnici già impiegati dall'ingegneria<br />
naturalistica terrestre. Biol. Mar. Mediterr., 14 (2): 342-343.<br />
GIOVANNETTI E., MONTEFALCONE M., BIANCHI C.N., MORRI C., ALBERTELLI G. (2006)<br />
- Structural variability of the epiphytic community in a Posidonia oceanica meadow (Ligurian<br />
Sea, NW Mediterranean). Biol. Mar. Mediterr., 13 (4): 145-148.<br />
TRAUTMAN D.A., BOROWITZKA M.A. (1999) - Distribution of the epiphytic organisms on<br />
Posidonia australis and P. sinuosa, two seagrasses with differing leaf morfology . Mar. Ecol.<br />
Prog. Ser., 179: 215-229.<br />
41 st S.I.B.M. CONGRESS Rapallo (GE), 7-11 June 2010<br />
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