Preprint volume - SIBM
Preprint volume - SIBM
Preprint volume - SIBM
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
Pre-print Volume - Oral presentations<br />
Topic 1: BIODIVERSITY AND CONSERVATION SCIENCE: CONTRIBUTING TO MANAGEMENT<br />
Conclusions – Results of the comparison between PITs and visual quadrats highlight a<br />
high variability among quadrats that hides the differences existing among sampling<br />
sites in zones subjected to a different protection regime. To overcame this limit a<br />
higher number of replicates is necessary, with a consequent increase in the amount of<br />
time spent underwater. On the contrary, PITs have a larger cost/time effectiveness,<br />
exhibit a lower variability among replicates and, because of their larger sampling size,<br />
should be better candidates to detect differences at larger spatial scales (Parravicini et<br />
al., 2009). The MDS plot also ordinates PIT replicates in a way that reflects the<br />
zonation of the MPA. However, the institution of the Isola di Bergeggi MPA is too<br />
recent, while a high number of studies (Claudet et al., 2008 and references therein)<br />
suggest that several years are necessary to make protection effects detectable. Our<br />
sampling sites were located along a inshore-offshore gradient, and the zonation of the<br />
‘Isola di Bergeggi’ MPA exactly superimposes over such a gradient. This might cause<br />
a problem in the future monitoring programs to discriminate protection effects from<br />
environmental constrains: a more appropriate design will be necessary to disentangle<br />
inshore-offshore and protection effects. Actually, visual quadrats and PITs are two<br />
complementary sampling techniques, because the former is able to detect the<br />
variability on the small scale, while the latter on the large scale.<br />
When comparing cover data with frequency data no significant differences between<br />
the two descriptors are found, both being able to collect the same information on<br />
benthic assemblages. However, we advocate the adoption of frequency to characterize<br />
benthic communities because it requests a comparatively shorter time for collecting<br />
data.<br />
References<br />
BIANCHI C.N., PRONZATO R., CATTANEO-VIETTI R., BENEDETTI-CECCHI L., MORRI C.,<br />
PANSINI M., CHEMELLO R., MILAZZO M., FRASCHETTI S., TERLIZZI A., PEIRANO A.,<br />
SALVATI E., BENZONI F., CALCINAI B., CERRANO C., BAVESTRELLO G. (2004) –<br />
Mediterranean marine benthos: a manual of methods for its sampling and study. Hard bottoms.<br />
Biol. Mar. Mediterr., 11: 185 215.<br />
CLAUDET J., OSEMBERG C.W., BENEDETTI-CECCHI L., DOMENICI P., GARCÍA-<br />
CHARTON J.A., PÉREZ-RUSAFA A., BADALAMENTI F., BAYLE-SEMPERE J., BRITO<br />
A., BULLERI F., CULIOLI J.M., DIMECH M., FALCÓN J.M., GUALA I., MILAZZO M.,<br />
SÁNCHEZ-MECA J., SOMERFIELD P.J., STOBART B., VENDEPERRE F., VALLE C.,<br />
PLANES S. (2008) – Marine reserves: size and age do matter. Ecology Letters, 11: 481-489.<br />
PARRAVICINI V., MORRI C., CIRIBILLI G., MONTEFALCONE M., ALBERTELLI G.,<br />
BIANCHI C.N. (2009) - Size matters more than method: visual quadrats vs photography in<br />
measuring human impact on Mediterranean rocky reef communities. Estuarine, Coastal and Shelf<br />
Science, 81: 358-367.<br />
Work partially done within the frame of the research project ‘The impacts of biological invasions and<br />
climate change on the biodiversity of the Mediterranean Sea’ (Italy–Israel co-operation, Italian<br />
Ministry of the Environment). Data were collected thanks to an agreement between DipTeRis and the<br />
MPA Authority Comune di Bergeggi.<br />
41 st S.I.B.M. CONGRESS Rapallo (GE), 7-11 June 2010<br />
41