Nicola Cantasano

In Calabria coastal regions, seaward and landward sides could be connected through the ecological role of fluvial catchments. Calabria Tyrrhenian coast shows a wilderness area, characterized by two terrestrial and marine Special Areas of Conservation (SACs) connected by the fluvial catchment of Verri stream. The bibliographic search was realized according to a Preferred Reporting Items for Systematic Reviews and Meta-Analysis, as a standardized method for screening the most relevant literature. The field survey, conducted in the study area, highlighted high biodiversity levels and a great natural heritage represented by 189 plant species and 130 animal ones. According to the resulting data, the basin represents a classical model of ecological corridor linking terrestrial and marine SACs, as cornerstones of Natura 2000 network, so representing the European assessment for biodiversity conservation. This paper highlights the high biological richness of a wilderness area showing the tight relationship between the continental and the marine districts of the same coastal region. The main goal of the research is to remark the fundamental role of fluvial corridors within a regional approach where riverine catchments could represent the connecting steps of the network. In Calabria it is hopeful to establish a functional connectivity amongst protected areas supported by fluvial corridors along the regional basins.

The Natura 2000 network is the main tool established by the European Union for biodiversity conservation. The cornerstones of this natural infrastructure are, actually, represented by the Special Areas of Conservation (SAC) and the Zones of Special Protection (ZPS). In the Calabria coastal region, this network is formed by 44 ZSCs widespread along the regional coastline. In this way, most of the Natura 2000 sites are located in continental areas, as 75% of the whole, and every key area includes some natural habitat types. In particular, the greater number of habitats is concentrated in transitional environments, as the case study located in the mouth of the Crati River, including 17 habitat types. However, the geographic distribution of Natura 2000 sites is quite unbalanced because most of the SACs are located in continental landscapes, 75% of the whole, while only 25% are concentrated in coastal regions. This irregular distribution of the network leads to a loss of biodiversity levels from continental to coastal areas. So, the implementation of the Natura 2000 network could be the main tool to connect terrestrial and coastal regions not only for biodiversity conservation but also to improve the social and economic conditions of local people.

Caulerpa cylindracea, Indo-Pacific and thermophilic macroalgal species, have spread in Italian coastal waters, especially in the western Mediterranean Sea. Also, along the Calabria coastline, this Invasive Alien Species (IAS) was able to colonize most of the western and eastern seasides of the region. This research was conducted between 1999 and 2021 through a detailed cost-effective citizen science program. The novelty of this research was to determine the overall distribution of Caulerpa cylindracea along Calabria seawaters from the Tyrrhenian to the Ionian coasts. The results of the monitoring survey highlighted the presence of Caulerpa cylindracea in 45 collecting stations throughout the Calabrian coastline. This regional assessment showed the extensive adaptability of the species to different environmental conditions: from exposed to sheltered sites, in shaded and sunny coastal areas and also throughout pristine and polluted waters. The rapid and increasing spread of the species could affect the structure of Mediterranean biota or, otherwise, could lead in time to new ecological niches. As highlighted in the most recent literature, it is necessary to update monitoring and mapping plans for the protection of marine biodiversity through close coordination between scientists, citizens and policy makers, all engaged to ensure effective management of invasive processes.

In the Mediterranean Sea, two critical issues affect marine benthic biocenosis: sedimentation and the increasing trend in marine biodiversity loss. These processes are very marked along the western side of the Calabrian coastline, where siltation is one of the main reasons for the regression of Posidonia beds in the regional coastal waters. This study investigates the relationships between the geomorphological features of the debris source areas, represented by fluvial basins, and the distribution of Posidonia meadows. So, a concise geomorphological study of the Tyrrhenian fluvial basins with an area greater than 200 km² was carried out, and we correlated the results with the mapping of the meadows in Calabria’s Tyrrhenian waters. Furthermore, to assess the increased level of burial in a Posidonia oceanica meadow and its health state over time, a program of Posidonia monitoring was undertaken between 2000 and 2010 in a test area located in the Marine Regional Park of Isca (Calabria, Southern Italy). The results of this survey highlighted that, at the beginning of the study period, the silting rate of 4–5 cm/year saw the meadow suffer a reduction in its photosynthetic ratio with a mortality rate of 50%. The siltation rate reached 12 cm/year in 2010, and the meadow began to disappear. Therefore, marine pollution via sedimentation represents a serious factor in the regression of Posidonia oceanica meadows and enhances the risk of a gradual loss of marine biodiversity.

Posidonia oceanica is an endemic species of the Mediterranean Sea that in pristine coastal waters forms extensive meadows, which are, actually, exposed to natural and anthropogenic pressures, causing their regression throughout the basin. The aim of our study is to summarise and evaluate current knowledge about the characterisation of Posidonia oceanica along the Western Algerian coast, in order to provide new evidence about the distribution and health status this species. To realize our objectives, we combined extracted data from published articles, theses, results of project reports, in situ observations and laboratory analysis. The results show the presence of the meadows in fifteen coastal zones of Western Algeria, mainly located in shallow surface waters from 0.5 to 18 metres depth.The mean leaf length across all sites ranged from 153 to 667 mm. The mean number of leaves/shoot ranged between 4.7 ± 0.9 and 6.0 ± 0.5 leaves/shoot. Leaf length showed a highly significant difference between the cold and hot season. The data analysis shows that the leaf biometric values and the shoot densities of the P. oceanica are greater than those of Mediterranean samples although these measures tend to decrease deeply. The analyses carried out on structural features of P. oceanica show that the Western Algerian meadows are, globally, in good health status according to standardised scale. The available data on P. oceanica summarised in this article represent an important starting point to build effective plans for understanding levels of environmental threats and for supporting conservation strategies for these important ecosystems. Conversely, the limited information available on this seagrass along the Western Algerian costs only allows the description of some structural features, and permits us to draw overall conclusions on its general health status.

General remarks * THE MAIN ISSUE ADDRESSED BY THE RESEARCH IS THE ANALYSIS OF TOURIST ACTIVITIES AND THEIR IMPACTS ON THE CULTURAL HERITAGE OF ZIMBABWE. * THE ARTICLE IS VERY INTERESTING BEACUSE IT SUGGESTS A NEW KIND OF ANALYSIS BASED ON CITIZEN...

The main issue addressed by the research is the evaluation of the hydrologic, geomorphic and vegetation parameters to assess natural, living and hardened shorelines along a coastal region. The topics discussed in the manuscript is very interesting b...

In the Mediterranean Sea, there are two critical issues affecting marine benthic biocenosis: the sedimentation process and the increasing trend in marine biodiversity loss. These processes are very marked along the western side of Calabria coastline where siltation is one of the main reasons for the regression of Posidonia beds in the regional coastal waters. This research aims to investigate the relationships between the geomorphological features of the debris source areas, represented by fluvial basins, and the distribution of Posidonia meadows. So, a geomorphological study of the Tyrrhenian fluvial basins with area greater than 200 km2 and its correlation with the mapping of the meadows in the Calabria Tyrrhenian waters was carried out. Furthermore, in order to assess the increased level of burial in a Posidonia oceanica meadow and its health state over time, a program of Posidonia monitoring was undertaken between 2000 and 2010, in a test area located in the Marine Regional Park of Isca (Calabria, Southern Italy). The results of this survey highlighted that, at the beginning of the study period, for a silting rate of 4 - 5 cm/year, the meadow suffered a reduction of its photosynthetic ratio with a rate of mortality of 50%. In the following years, the siltation rate reach 12 cm/year in 2010 and the meadow began to disappear. Therefore, the marine pollution by sedimentation represents a serious factor for the regression of Posidonia oceanica meadows, enhancing the risk of a gradual loss in marine biodiversity.

Climate changes are affecting the fate of Posidonia oceanica meadows. Actually, the Mediterranean Sea is threatened by abiotic, biotic and climate changes coupled with human pressures regarding coastal regions. In this way, Posidonia oceanica is able to counteract the effects of climate changes through the high thermotolerance of the species, range shift processes of the meadows and variations in the community composition of this valuable marine ecosystem. Anyway, the power of acclimatization to temperature shifts and the adaptative capacity of Posidonia oceanica meadows against human pressures let to suggest a positive trend in the long evolutionary pathway of the species.

Posidonia oceanica (Linnaeus) Delile is one of the most important endemic species of the Mediterranean Sea. The long phylogenetic pathway of this species deserves special attention because its evolutionary history allows us to think back over the debated issue of life evolution on Earth. Hence, this marine plant, by terrestrial origin, was born from an ancient ancestor named Posidonia cretacea Hosius & Von der Marck. This seagrass species, currently extinct, lived in the coastal waters of the Tethys Ocean about 100 million years ago, during the geological times of the late Cretaceous. In the following Cenozoic Era, during the Miocene period, in the time lag from sixty to forty million years ago,a long process of allopatric speciation by separate areas led to eight species of Posidonia genus developed in the northern and southern hemispheres. Posidonia oceanica is established in the boreal marine regions, so representing, within the long and winding road of life evolution on Earth, a typical example of paleo-Mediterranean relict. Nowadays, Posidonia oceanica meadows perform important ecological functions in the Mediterranean Sea, not only for biodiversity conservation but also to mitigate climate change. In this way, meadows play a leading role in carbon sequestration, reducing the concentration of carbon dioxide in coastal waters. Lastly, the meadows of Posidonia oceanica promote an effective removal process of plastic debris from Mediterranean sea waters.