ecological effects of marine protected areas empafish project ...

EMPAFISH Booklet no. 1 Ecological effects of Atlanto-Mediterranean MPAs in the EU
Contacts
Ente Parco Nazionale Arcipelago Toscano
Via Guerrazzi, 1, I-57037, Portoferraio (LI), Italy
Tel: +39-0565-919411 / Fax: +39-(0)565-919428
Email: parco@islepark.it
Website: www.islepark.it
Tuscany archipelago: ecological studies
� General
o Benthic communities
The ecology of benthic assemblages was investigated in the area since the
late 1990s. Patterns of variability of mid-shore and low-shore algal and
invertebrate assemblages on Tuscany Archipelago rocky shores were
investigated at several scales in space and time. It was documented large
variability of organisms across the vertical gradient of the shore and
horizontal variability mainly at small (10s of cm) and large (100s to 1000s of
m) spatial scale (Benedetti-Cecchi 2001). As part of these studies,
assemblages of rocky shores on islands were compared to those of the
mainland in order to examine if insular assemblages could be considered
unique because they are exposed to particular patterns of
colonization/extinction depending on distance from other sources of colonists
and on size of islands, or if islands provide different habitats, regardless of
potential effects of size and isolation. Structure of assemblages, mean
abundance of common taxa and magnitude of spatial and temporal variance
in abundance at mid-shore and low-shore habitats differed between islands
and the mainland, indicating that islands in the Tuscany Archipelago
contributed to diversity and complexity of rocky shore assemblages over and
above any possible effect of size and isolation (Benedetti-Cecchi et al. 2003a).
Patterns in distribution and demography were analysed in detail for the
barnacle Chthamalus stellatus, indicating large temporal and spatial variability
at different scales, probably driven by pre-emption of the substratum and
mortality of juveniles (Benedetti-Cecchi et al. 2000a).
Data from experiments of exclusion of limpets documented the importance of
grazing by limpets in maintaining differences between mid-shore and lowshore
algal assemblages, with patterns generally independent of the
inclination of the substratum, but largely variable in space and time
(Benedetti-Cecchi et al. 2000b, 2001a). Empirical data were also related to
predictions obtained from simulations, indicating that the understanding of
effects of consumer documented could be implemented by including in foodweb
models changes in variance of trophic interactions (Benedetti-Cecchi
2000).
The occurrence of canopy-forming algae in the genus Cystoseira in the area of
Tuscany Archipelago appeared related to anthropogenic disturbance, as
indicated by their dominance on relatively pristine shores and their virtual
absence in urban areas, where, in contrast, they were replaced by turf-
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