Oceanographic and anthropogenic variables driving marine litter distribution in Mediterranean protected areas: Extensive field data supported by forecasting modelling.

Marine litter concentration in the Mediterranean Sea is strongly influenced both by anthropogenic pressures and hydrodynamic factors that locally characterise the basin. Within the Plastic Busters MPAs (Marine Protected Areas) Interreg Mediterranean Project, a comprehensive assessment of floating macro- and microlitter in the Pelagos Sanctuary and the Tuscan Archipelago National Park was performed. An innovative multilevel experimental design has been planned ad-hoc according to a litter provisional distribution model, harmonising and implementing the current sampling methodologies. The simultaneous presence of floating macro- and microlitter items and the potential influences of environmental and anthropogenic factors affecting litter distribution have been evaluated to identify hotspot accumulation areas representing a major hazard for marine species. A total of 273 monitoring transects of floating macrolitter and 141 manta trawl samples were collected in the study areas to evaluate the abundance and composition of marine litter. High mean concentrations of floating macrolitter (399 items/km2) and microplastics (259,490 items/km2) have been found in the facing waters of the Gulf of La Spezia and Tuscan Archipelago National Park as well in the Genova canyon and Janua seamount area. Accordingly, strong litter inputs were identified to originate from the mainland and accumulate in coastal waters within 10-15 nautical miles. Harbours and riverine outfalls contribute significantly to plastic pollution representing the main sources of contamination as well as areas with warmer waters and weak oceanographic features that could facilitate its accumulation. The results achieved may indicate a potentially threatening trend of litter accumulation that may pose a serious risk to the Pelagos Sanctuary biodiversity and provide further indications for dealing with plastic pollution in protected areas, facilitating future management recommendations and mitigation actions in these fragile marines and coastal environments.

Monitoring the composition, sources and spatial distribution of seafloor litter in the Adriatic Sea (Mediterranean Sea) through Fishing for Litter initiatives.

Although the seafloor is an important sink for marine litter, its less accessible environment makes seafloor litter the least studied component. Nevertheless, detailed monitoring of its composition and spatial distribution is urgently needed to develop appropriate mitigation strategies in areas exposed to multiple anthropogenic pressures, such as the Adriatic Sea. Commercial fisheries such as bottom trawls can serve as an opportunistic platform for collecting data on seafloor litter and help researchers in addressing the lack of data through Fishing for Litter initiatives. In this study, the crews of twelve trawlers from two Italian Adriatic ports collected seafloor litter as part of their Fishing for Litter initiatives. In addition to the classical scheme, the collected litter was sorted on board into different bags, and speed, duration and geographical coordinates of each haul were recorded to allow an assessment of both densities and spatial distribution. More than 600 kg of litter was removed from the seafloor by the fishers in approximately 1 month and characterised by the researchers on the docks. Most of the found items were made of synthetic polymers and related to packaging, fisheries and aquaculture activities. Abandoned, lost or discarded fishing gear and mussel nets were identified as of particular concern in the maritime compartment of Chioggia and Civitanova Marche, respectively. Three hotspots for marine litter were identified: near the Venice lagoon, in the centre of the northern basin and at greater depth in the central Adriatic. This study provides a detailed picture of the spatial distribution and composition of seafloor litter in the areas studied and highlights the importance of increased cooperation between fishermen and scientists to improve the identification of hotspots and sources while removing marine litter from the seafloor and raising awareness of the problem.

Immigration as the main driver of population dynamics in a cryptic cetacean.

Empirical evidence about the role and interaction of immigration with local demographic processes in shaping population dynamics is still scarce. This knowledge gap limits our capability to derive a conceptual framework that can be used to inform conservation actions. Populations exposed to nonstationary environment do not converge to a stable stage distribution, implying the need for evaluating the demographic role of both vital rates and stage distribution using appropriate tools. This is particularly important for species with larger generation times like cetaceans. We explored the relative demographic role of vital rates and population structure of a poorly known cetacean, the Mediterranean Cuvier's beaked whale, while accounting for the exposure to nonstationary environments. We performed a retrospective analysis through transient life table response experiments (tLTRE) using demographic rates and population structure of both sexes obtained from an integrated population model. The contribution of immigration to variation in realized population growth rates was 4.2, 7.6, and 12.7 times larger than that of female apparent survival, proportional abundance of breeding females with a 2-year-old calf, and proportional abundance of breeding females with a 3-year-old calf, respectively. Immigration rate and proportional abundance of breeding females with a 2- or 3-year-old calf explained, respectively, 65% and 20% of total temporal variability in realized population growth rates. Changes in realized population growth rate between successive years were mainly driven by changes in immigration and population structure, specifically the proportional abundance of breeding females with a 2-year-old calf. Our study provides insight into the demographic processes that affect population dynamics and in a cryptic cetacean. We presented an analytical approach for maximizing the use of available data through the integration of multiple sources of information for individuals of different distinctiveness levels.

Microplastic abundance and biodiversity richness overlap: Identification of sensitive areas in the Western Ionian Sea.

Plastic pollution in the Mediterranean Sea has been widely reported, but its impact on biodiversity has not been fully explored. Simultaneous sampling of microplastics (MP) with a manta net and surveys of large marine vertebrates were conducted along the coastal waters of Sicily (Western Ionian Sea). A total of 17 neustonic samples have been collected and 17 marine species (cetaceans, sea turtles, seabirds, and fish) have been sighted in the target area. Kernel density estimation was evaluated to highlight a possible overlap between the presence of large marine fauna and MP densities to provide a preliminary risk assessment. The highest biodiversity and MP concentration (0.197 ±â€¯0.130 items/m2) were observed in the southernmost part of the studied area. The overlap between biodiversity hotspots and the occurrence of MP, potential contribute to the identification of sensitive areas of exposure in a poorly studied region.

First assessment of POPs and cytochrome P450 expression in Cuvier's beaked whales (Ziphius cavirostris) skin biopsies from the Mediterranean Sea.

The Cuvier's beaked whale (Ziphius cavirostris) is one of the least known cetacean species worldwide. The decreasing population trend and associated threats has led to the IUCN categorising the Mediterranean subpopulation as Vulnerable on the Red List of Threatened Species. This study aimed to investigate for the first time the ecotoxicological status of Cuvier's beaked whale in the NW Mediterranean Sea. The study sampled around the 20% of the individuals belonging to the Ligurian subpopulation, collecting skin biopsies from free-ranging specimens. The levels of polychlorinated biphenyl (PCBs), polybrominated diphenyl ethers (PBDEs) and induction of cytochrome's P450 (CYP1A1 and CYP2B isoforms) were evaluated. Results highlighted that the pattern of concentration for the target contaminants was PCBs > PBDEs and the accumulation values were linked to age and sex, with adult males showing significantly higher levels than juvenile. Concerns raised by the fact that 80% of the individuals had PCB levels above the toxicity threshold for negative physiological effects in marine mammals. Therefore, these findings shed light on this silent and serious threat never assessed in the Mediterranean Cuvier's beaked whale population, indicating that anthropogenic pressures, including chemical pollution, may represent menaces for the conservation of this species in the Mediterranean Sea.

Trends in summer presence of fin whales in the Western Mediterranean Sea Region: new insights from a long-term monitoring program.

BACKGROUND: The Mediterranean subpopulation of fin whale Balaenoptera physalus (Linnaeus, 1758) has recently been listed as Vulnerable by the IUCN Red List of threatened species. The species is also listed as species in need of strict protection under the Habitat Directive and is one of the indicators for the assessment of Good Environmental Status under the MSFD. Reference values on population abundance and trends are needed in order to set the threshold values and to assess the conservation status of the population. METHODS: Yearly summer monitoring using ferries as platform of opportunity was performed since 2008 within the framework of the FLT Med Network. Data were collected along several fixed transects crossing the Western Mediterranean basin and the Adriatic and Ionian region. Species presence, expressed by density recorded along the sampled transects, was inspected for assessing interannual variability together with group size. Generalized Additive Models were used to describe density trends over a 11 years' period (2008-2018). A spatial multi-scale approach was used to highlight intra-basin differences in species presence and distribution during the years. RESULTS: Summer presence of fin whales in the western Mediterranean area showed a strong interannual variability, characterized by the alternance of rich and poor years. Small and large groups of fin whales were sighted only during rich years, confirming the favorable feeding condition influencing species presence. Trends highlighted by the GAM can be summarized as positive from 2008 to 2013, and slightly negative from 2014 to 2018. The sub-areas analysis showed a similar pattern, but with a more stable trend during the second period in the Pelagos Sanctuary sub-area, and a negative one in the other two sub-areas. Our findings further confirm the need for an integrated approach foreseeing both, large scale surveys and yearly monitoring at different spatial scales to correct and interpret the basin wide abundance estimates, and to correlate spatial and temporal trends with the ecological and anthropogenic drivers.

Acoustic recordings of rough-toothed dolphin (Steno bredanensis) offshore Eastern Sicily (Mediterranean Sea).

Rough-toothed dolphin's abundance and distribution is largely unknown worldwide and evaluation of its conservation status in the Mediterranean Sea is necessary. A rough-toothed dolphin was sighted offshore Eastern Sicily (Mediterranean Sea) in July 2017 and acoustic data were acquired in the same area of Watkins, Tyack, Moore, and Notarbartolo di Sciara [(1987). Mar. Mamm. Sci. 3, 78-82]. An automatic detection algorithm was developed to identify the echolocation clicks recorded within both datasets and a recurrent inter-click interval value was identified during the new encounter. Distinctive whistle classes were also identified with similar contour shapes within both datasets.

Sexing free-ranging adult Cuvier's beaked whales ( Ziphius cavirostris ) using natural marking thresholds and pigmentation patterns.

Sex identification of adult cetaceans is an important ecological parameter that should be incorporated into studies such as population dynamics and animal behavior. In Cuvier's beaked whale ( Ziphius cavirostris ), sex determination may be achieved through genetics, observation of genitals, the presence/absence of erupted teeth, and calf association. However, these features are difficult to ascertain due to the shy behavior of this species. Therefore, this study aimed to create a robust sex identification method using only external characteristics. Particularly, this work analyzed pigmentation patterns and levels of natural marks from adult individuals of known sex in order to identify gender differences, using frequency analysis and generalized linear models. Photographic captures of 73 free-ranging animals were utilized. The frequencies of the individual pigmentation patterns were found to be sex dependent. The 63% of the animals could be classified into either a "soft" or "sharp" pigmentation cluster. The "soft" cluster was only displayed by females, while the "sharp" cluster was present in both the sexes. However, the model selection process indicated that natural marking is the best determinative factor for sex classification. The density of the visible intraspecific natural marks was found to differ between the sexes ( P value < 0.001) and was incorporated as a predictor variable into several candidate models. All candidate models had a high predictive power (mean area under the curve 0.973) and correctly predicted the sex, by means of a density threshold value, in 85-90% of the analyzed animals. The density threshold ranged from 4.1% to 6.4% according to the different body area analyzed. These density threshold values represent a robust post hoc sexing method to classify individuals to sex from opportunistic photos in the absence of other sexing methods.