Abstract:
Recently completed sedimentological and palaeontological analyses of the Messinian deposits of western Sardinia yielded
dating, palaeoenvironmental and new sequence stratigraphic interpretations.
The Basal Marls and the Capo San Marco Formation are referred to the Messinian. Both formations were deposited in a
ramp setting, whereas the overlaying Sinis Limestone Formation is interpreted as a carbonate platform of wide extent, probably
equivalent to part of the Terminal Carbonate Complex. All these deposits are considered to have formed under normal marine
conditions. The three formations developed during one and a half cycles of progradation –retrogradation.
Compared with other Messinian Mediterranean carbonate platforms, the Sinis Peninsula exhibits several unusual
features:
(1) The notable absence of scleractinian coral reefs is related to dominantly cool seawater in this area.
(2) The Capo San Marco Formation contains widespread microbial –bryozoan –serpulid carbonate buildups, partially
associated with upwelling currents.
(3) The breccias at the top of the Sinis Limestone Formation are regarded as resulting from a major seismic shock
over the whole peninsula
We investigated the applicability of the Pearson–Rosenberg (P–R) conceptual model describing a generalized pattern of response of benthic communities in relation to organic enrichment to Mediterranean Sea coastal lagoons. Consistent with P–R model predictions, benthic diversity and abundance showed two
different peaks at low (>2.5–5 mg g_1) and high (>25–30 mg g_1) total organic carbon (TOC) ranges, respectively. We identified TOC thresholds indicating that risks of reduced benthic diversity should be relatively low at TOC values < about 10 mg g _1, high at TOC values > about 28 mg g, and intermediate at values in-between. Predictive ability within these ranges was high based on results of re-sampling simulation.
While not a direct measure of causality, it is anticipated that these TOC thresholds should serve as a general screening-level indicator for evaluating the likelihood of reduced sediment quality and associated bioeffects in such eutrophic systems of the Mediterranean Sea.
Abstract:
Mapping of benthic assemblages of the coastal zone was realised in the Marine Protected Area of Sinis - Mal di Ventre (Western Sardinia) in order to identify the suitable areas for the anchoring of pleasure boats. Based of the nature of substrata and benthic assemblages different solutions for the management of anchoring were proposed.
