An updated checklist of chondrichthyans of Calabria (Central Mediterranean, southern Italy), with emphasis on rare species

In this contribution the checklist of chondrichthyans of Calabria (Central Mediterranean, southern Italy) is reported. Data presented is derived from twenty years of opportunistic and active surveys from 2000 to 2020. A total of 55 species of chondrichthyans is present in Calabrian seas: 33 sharks, 20 rays, and 2 chimaeras. These species represent approximately 62% of the total reported for the Mediterranean. Approximately 71% of Calabrian species have been reported in the Tyrrhenian Sea, 49% in the Ionian Sea, and 33% in the Strait of Messina. According to IUCN criteria, new records of Endangered and Critically Endangered species (i.e., Carcahrodon carcharias [Linnaeus, 1758], Lamna nasus [Bonnaterre, 1788], Cetorhinus maximus [Gunnerus, 1765], Mobula mobular [Bonnaterre, 1788], Sphyrna zygaena [Linnaeus, 1758]) are reported, together with the first record of Raya brachyura Lafont, 1873 for the Ionian coasts and probably third confirmed record of the rare chimaera Hydrolagus mirabilis (Collett, 1904) for the Mediterranean

Bioaccumulation of Trace Elements in the Muscle of the Blackmouth Catshark Galeus melastomus from Mediterranean Waters

Environmental pollution, particularly in the marine environment, has become a significant concern due to the increasing presence of pollutants and their adverse effects on ecosystems and human health. This study focuses on the bioaccumulation of trace elements in the muscle tissue of the blackmouth catshark (Galeus melastomus) from different areas in the Mediterranean Sea. Trace elements are of interest due to their persistence, toxicity, and potential for bioaccumulation. This research aims to assess the distribution and accumulation of trace elements in the muscle tissue of G. melastomus and investigate their potential impact on the deep-sea environment of the Mediterranean. The focused areas include the Ligurian Sea, the northern and central Tyrrhenian Sea, the southern Tyrrhenian Sea, the Ionian Sea, the Pantelleria Waters, and the Gela Waters. Samples were collected following established protocols, and trace element analysis was conducted using inductively coupled plasma mass spectrometry. The study provides data on the concentrations of 17 trace elements, namely aluminum, arsenic, cadmium, cobalt, copper, manganese, molybdenum, nickel, zinc, selenium, strontium, lead, chromium, iron, barium, bismuth, and uranium. The findings contribute to a better understanding of trace element bioaccumulation patterns in elasmobranch species, specifically G. melastomus, and highlight the potential risks associated with chemical contamination in the Mediterranean Sea. This research emphasizes the importance of studying the impacts of pollutants on marine organisms, particularly those occupying key ecological roles, like sharks, to support effective conservation and management strategies

First toxicological study in two commercial shark species from a Mediterranean Marine Protected Area

Large urban and industrial settlements, and the intense maritime traffic make the Mediterranean one of the most polluted areas in the world. This basin hosts considerable marine biodiversity, including many elasmobranchs, which are extremely vulnerable to environmental contamination due their life history traits. The impact of this threat on the cartilaginous fishes is still poorly studied, as well as the possible consequences for human health, in case of consumption of sharks, are uncertain. To fill this knowledge gap, quantitative and qualitative assessments of three groups of persistent organic pollutants (POPs) were carried out in the muscle and liver of two shark species, Mustelus punctulatus and Mustelus mustelus, caught in the Marine Protected Area (MPA) of Egadi Islands (South-Central Mediterranean Sea) between 2021 and 2023. As sharks are one of the top predators inhabiting the MPA, they can be considered a bioindicator of the local environmental status. Paradoxically, although M. punctulatus and M. mustelus have considerable commercial value for human consumption in the MPA, they are listed as Vulnerable by the IUCN in the Mediterranean. Regarding POPs levels, the results showed a trend of PCBs > DDTs >> HCB in liver and muscle for both species. Our results can significantly contribute to clarify the toxicological status of these species, allowing a first evaluation of the real risks both for the local marine life and for human health

A nursery area for the Antarctic silverfish Pleuragramma antarcticum at Terra Nova Bay (Ross Sea): first estimate of distribution and abundance of eggs and larvae under the seasonal sea-ice.

none7Pleuragramma antarcticum is the dominant pelagic fish in the waters of the continental shelf in high Antarctic regions, where it plays a key role in the food web. A nursery ground for eggs of this species was first identified in 2002 in Terra Nova Bay (Ross Sea), where eggs were found trapped in ice platelets under the sea-ice during the spring. As part of a monitoring program aimed atunderstanding the geographic and temporal characteristics of this nursery ground, the present study reports on surveys carried out in the austral springs of 2005 and 2006 using a simple and effective method for sampling from the sea-ice. These surveys enabled the evaluation of the spatial range ofthe nursery area of the Antarctic silverfish in the sea-ice ofthe coastal area of Victoria Land between the Coulman Island and the Drygalski Glacier Tongue. P. antarcticum eggs were concentrated in an area of Terra Nova Bay of about 270 km2, encompassing two adjacent sites, Gerlache Inlet and Silverfish Bay. The present results add informationon life cycle and hatching period of the Antarctic silverfish and confirm the importance of the Terra Nova Bay as a nursery area for this important species. Moreover, the survey points to the sea-ice cover and platelet ice as important environmental features of the nursery area.M.Vacchi; A.L. DeVries; C.W. Evans; M. Bottaro; L. Ghigliotti; L. Cutroneo; E. PisanoVacchi, M.; Devries, A. L.; Evans, C. W.; Bottaro, M.; Ghigliotti, Laura; Cutroneo, L.; Pisano, Ev

Spatiotemporal distribution of great white shark (Carcharodon carcharias, Linnaeus 1758) along Italian coasts: Records from international Medlem program and other contributions

The Great white shark (Carcharodon carcharias Linnaeus 1758), is an apex predator living in almost all the seas of the world, preferring cold-temperate and temperate waters among the 8 and the 25° C (Compagno et al., 2005). It is nevertheless present with important populations in only 8 areas of the globe: California and Baja California, Mexico, central Chile, New England, Mediterranean Sea, Western South Africa, southern Australia, New Zealand and Japan (Compagno et al., 2005). Recently it was added to IUCN redlist as vulnerable species (IUCN 2001). It is one of the 72 species that have been observed in Italian waters (Vacchi & Serena, 2010), the biology and ecology of this shark is still quite misunderstood. Despite being aware of the importance of this species in the marine ecosystem (Carey et al., 1982; Casey & Pratt, 1985; Klimley et al., 1992) and in spite attention paid to it by the public, much remains to be discovered about the Mediterranean Great White Shark. The aim of the present work was to organize and analyze data concerning the spatiotemporal pattern of distribution of white sharks along Italian coasts, collected by international LEM programme database and by other contributions

Abundance and distribution of the white shark in the Mediterranean Sea

Conservation of apex predators is a key challenge both in marine and terrestrial ecosystems. The white shark is a rare but persistent inhabitant of the Mediterranean Sea and it is currently assessed as “critically endangered” in the region. However, the population trends and dynamics of this species in the area are still unknown. Little is known about white shark distribution, habitat use and population abundance trends, aspects that are critical for conservation and management. In this study, we built the most comprehensive database of white shark occurrence records in the region. We collected 773 different records from different sources and used them to characterize the spatial and temporal patterns of abundance of Mediterranean white sharks between 1860 and 2016. We analysed these data by using generalized additive models and used spatially disaggregated information on human population abundance as a proxy of observation effort. Our results suggest a complex trajectory of population change characterized by a historical increase and a more recent reduction (61%, range 58%–72%) since the second half of the 20th century. In particular, analyses reveal a 52% (range 37%–88%) to 96% (range 92%–100%) overall decline in different Mediterranean sectors and a contraction in spatial distribution. Here, we provide the first reconstruction of abundance trends and offer new hypotheses regarding the drivers of change of white sharks in the Mediterranean. Our approach can be broadly applied to data-poor contexts to reconstruct change and inform the conservation of endangered top predators in the Mediterranean Sea and other intensely used marine regions