Functional diversity of benthic assemblage associated to aquacultured and wild Mytilus galloprovincialis clumps in the northern Adriatic Sea.

The aim of this work was to evaluate the spatio-temporal variability in the functional structure of the fauna living in association with farmed and wild populations of mussel Mytilus galloprovincialis (Lamarck 1819). Five functional traits were analysed: Bioturbation, Body size, Feeding habit, Larval development and Adult mobility, each having more life modalities. Detailed literature analysis (284 papers and 4 internet databases) was performed and to each species life modalities of the 5 life traits were assigned, using fuzzy coding procedure. Univariate analyses of the calculated functional diversity indices (i.e., functional richness (FR), functional evenness (FE) and functional divergence (FD)) were done to test for differences between farm and natural habitats, sampling time and sites. Multivariate statistical analysis was carried out to test for differences in the functional structure of the macrobenthic community between habitats, time, and sites. The most abundant life modalities were Superficial modifier, body size 10-50 mm, Suspension/filter feeder, Direct development, and Swimmer. In general, a) functional richness was significantly higher in wild sites in autumn, b) functional evenness showed similar mean values between habitat type, time, and sites, while c) functional divergence was significantly higher in wild sites in both seasons. Functional structure of the benthic communities was significantly different between farm and natural habitats, times, sites and for the interaction time/habitat. These differences were due to the different species composition and abundance between habitat types and seasons, related to the different life cycles of the species, the different environmental conditions and anthropogenic disturbances present in these habitats. This thesis can be considered as a starting point for further studies regarding functional ecology of mussel beds, to improve their monitoring and carry out necessary management steps.