Microbial communities provide essential information about host ecology and could be helpful as a tool to improve species conservation efforts. However, microbes can also infect and compromise the host development process and viability. Caretta caretta is the most widespread marine turtle species in the Mediterranean basin and is the only species of sea turtle nesting along the Italian coasts. Little is known about the microbiota composition of the nest of sea turtles and its correlation with hatching failures. In this study, the microbial composition of two nests of C. caretta featuring different rates of hatching success from a nesting beach in Lampedusa (Italy) was analyzed and compared. The bacterial community was determined using culture-dependent methods and next-generation sequencing based on 16S rRNA gene metabarcoding analysis. Our results showed five dominant bacterial phyla (Proteobacteria, Bacteroidetes, Actinobacteria, Verrucomicrobia, and Firmicutes) and indicated different bacterial families (Pseudomonadaceae and Brucellaceae) as likely causes of hatching failures. Besides, our findings demonstrated the nests’ active role in modulating the sand’s bacterial communities. This study suggests microbiological analysis could be a valuable tool in monitoring nests to take preventive actions and reduce hatching failures.

Sexual dimorphism, ontogenetic variation and allometric shape changes related to variation in size were considered and eliminated before performing discriminant analyses on geographic variation of Apodemus sylvaticus in central Mediterranean areas. Preliminary multivariate analyses of A. sylvaticus populations showed influences of sex and age in the ordination results. Giantism, i.e. size increase and shape-related change, was more pronounced on islands like Pantelleria and Marettimo. By principal component analysis, we found an allometric factor which proved statistically correlated to insularity parameters (area, distance from mainland, and altitude) but not to the number of predator and competitor species in the seven islands. Application of Burnaby's procedure permitted a 'size-free' multivariate analysis, (canonical variate analysis and related Mahalanobis distances, their UPGMA clustering and minimum spanning tree), which showed ordination of populations independent of within-group size variation and sample composition. The resulting pattern of geographic variation was considered an example of independent divergence of island populations. The wood mouse in Algeria and Tunisia is morphometrically related to the northern Italian population; a second cluster grouped the seven islands and the Calabrian population. The latter and that of Marettimo appear to be the more phenetically separated populations. Pantelleria and Malta form a distinct sub-group separated from Sardinia and Sicily. The minimum spanning tree joined the north-eastern Sicilian populations to those of the small islands and to Calabria, whereas the south-western populations proved to be connected to those of Tunisia. These relationships in skull morphometrics may result from adaptation to similar ecological conditions or can probably be traced to Holocene colonization events.

Atmospheric CO2 concentrations can reach high levels inside natural caves, representing a hazardous condition for both humans frequenting the underground environment and its safeguard due to the corrosion of speleothems induced by the acidification of atmospheric moisture. These issues are particularly critical for the eco-sustainable management of caves protected as nature reserves and undergoing touristic exploitation. In this paper we present the results of the C6 project, which was activated in 1999 for the monitoring of air quality inside three caves protected as nature reserves in Sicily (Italy). Near-real-time and spot measurements of air temperature and CO2 concentration have been carried out since the year 2000, giving the opportunity of evaluating the gas hazard for visitors and its potential impact on the protected underground environments, as well as the influence of meteorological and hydrological conditions in driving carbon dioxide accumulations. The analysis of data acquired in the hypogeal atmosphere, and their comparison with analogous epigeal measures, indicates that carbon dioxide accumulation is controlled by a complex interaction among cave topography, meteorological dynamics, gaseous exchanges between groundwaters and the atmosphere, and human fruition. This last factor, under particular conditions, can surprisingly diminishing underground CO2 concentrations.