This study reports the quantification and analysis of the ecosystem services (ESs) value of Posidonia oceanica (L.) Delile (1813) meadows in Italy (Liguria, Tuscany, Latium, Campania, Calabria, Apulia, Sardinia, and Sicily regions). The ES evaluation method of P. oceanica meadows applied in this study was obtained from a previous study in which the site-specific approach for the definition of the benefits and services was applied. The distribution of P. oceanica and the ESs economic value have been managed through an open-source geographic information system (QGIS), focusing on five essential ESs: carbon sequestration, bioremediation, oxygen production, erosion protection, and food production. The average value of the ESs obtained on the Italian national scale is €21,660.5 ha⁻¹ yr⁻¹, which is comparable with the values reported in the international literature concerning P. oceanica ESs. The results of this study confirm that the economic evaluation of ESs is an essential tool for the management of the coastal marine environment, especially considering the modularity of the applied approach. The value of the total benefits, considering the entire extension of the national P. oceanica meadows, represents significant value with respect to the Italian gross domestic product, and the individual budgets of the considered Italian regions.

Posidonia oceanica (L.) Delile meadows are recognized to be one of the most productive ecosystems of the Mediterranean basin. Due to the impacts of human activities in coastal areas, seagrasses are experiencing a critical decline. In this context, the understanding of the dynamics of production and photosynthesis in response to the environmental factors is essential to address efficient conservation strategies that limit this trend and to assess the ecological status of marine ecosystems. Pulse Amplitude Modulated (PAM) fluorometry has been widely implemented to assess seagrass health and productivity. Here we analyzed the photosynthetic dynamics of P. oceanica according to its bathymetric distribution and daily light availability along a depth gradient to be used as baseline for monitoring purposes on the health status of the seagrass meadows in the Northern Tyrrhenian Sea. Moreover, to investigate the effects of the environmental factors on the health status of P. oceanica within the study area through a multidisciplinary approach, the models contained in the Civitavecchia Coastal Environmental Monitoring System were used. In this study, significant photo-physiological changes have been observed among the investigated meadows. Moreover, the integration of physiological and hydrodynamic information allowed the description of how P. oceanica modulates its photosynthetic capacity at different environmental conditions.

The aim of the study was to evaluate the effectiveness of the application of multiple environmental descriptors through an asymmetrical sampling design to detect possible impacts related to the Costa Concordia event on the coastal marine environment. The Costa Concordia shipwreck occurred on a submerged rocky reef in the north-western Mediterranean Sea and the wreck was removed 2 years later. To achieve the proposed objective two main coastal ecosystems, the seagrass Posidonia oceanica and coralligenous assemblages were studied using two ecological indices, PREI and ESCA, respectively. Both indices show a lower ecological quality in the disturbed sites compared with the control ones. Differences between the disturbed and control sites observed in both studied ecosystems would seem to indicate an increase of turbidity around the shipwreck as the most plausible cause of impact. The concurrent use of different ecological indices and asymmetrical sampling designs allowed detection of differences in ecological quality of the disturbed sites compared with the controls. This approach may represent an interesting tool to be employed in impact evaluation studies.

Epiphytes cover on Posidonia oceanica leaves in the area affected by Costa Concordia wreck (Giglio Island, Tuscany, Italy) have been assessed as indicator of environmental quality within the integrated monitoring plan set up after the accident. Bryozoans have wide habitat distribution and are one of the most common sessile organisms in the epiphytic community of P. oceanica, have large species diversity and so are potential indicators of environmental factors and changes. The samples were taken from shortly after the sinking of the ship until just before the removal of the wreck in July (2012, 2013 and 2014). Three sampling sites were selected according to an asymmetric hierarchical experimental design. Three sampling areas of approximately 5 × 5 m and tens of meters apart from each other were randomly selected in each site. Five orthotropic shoots were collected haphazardly for each area. The sites were differently related to the influence of the wreck; one impact and two control sites. Percentage cover of bryozoan species was evaluated on the whole internal face of the four outer leaves per shoot. The analysis of the epiphyte community allowed us to identify most species normally present on these substrates. Besides a high natural spatio-temporal variability, feeble differences in the bryozoan assemblages were detected between the site near the wreck and the control sites, probably as a consequence of several synergic effects, firstly to the physical presence of the wreck and of the wreck removal yard.

Epiphytes cover on Posidonia oceanica leaves in the area affected by Costa Concordia wreck (Giglio Island, Tuscany, Italy) have been assessed as indicator of environmental quality within the integrated monitoring plan set up after the accident. Bryozoans have wide habitat distribution and are one of the most common sessile organisms in the epiphytic community of P. oceanica, have large species diversity and so are potential indicators of environmental factors and changes. The samples were taken from shortly after the sinking of the ship until just before the removal of the wreck in July (2012, 2013 and 2014). Three sampling sites were selected according to an asymmetric hierarchical experimental design. Three sampling areas of approximately 5 × 5 m and tens of meters apart from each other were randomly selected in each site. Five orthotropic shoots were collected haphazardly for each area. The sites were differently related to the influence of the wreck; one impact and two control sites. Percentage cover of bryozoan species was evaluated on the whole internal face of the four outer leaves per shoot. The analysis of the epiphyte community allowed us to identify most species normally present on these substrates. Besides a high natural spatio-temporal variability, feeble differences in the bryozoan assemblages were detected between the site near the wreck and the control sites, probably as a consequence of several synergic effects, firstly to the physical presence of the wreck and of the wreck removal yard.