Marine environments worldwide are affected by various anthropogenic activities, and many cetacean populations face increasing human pressures, especially those in coastal habitats. The key threats affecting common bottlenose dolphins (Tursiops truncatus) today are fishery interactions, prey depletion, habitat disturbance, pollution and climate change. The Mediterranean basin is one of the areas subjected to enormous pressure from human activities, in particular the Adriatic Sea, where bycatch represents the most frequent cause of dolphin mortality related to fisheries, followed by larynx strangulations, long-term tail entanglement and presence of fishing gear residue in the stomach. In this study, we present the first published case of a resident bottlenose dolphin from the Adriatic Sea population with a known observation history and confirmed cause of death observed in the Croatian part of the Adriatic Sea. By comparing the photographs of the dolphin’s dorsal fin taken during the post mortem examination with those obtained from boat-based surveys, we were able to identify the individual L_1834, which has been observed since 2018 along the eastern coast of the northern Adriatic Sea. Over three decades of monitoring live bottlenose dolphins and their systematic mortality surveillance in Croatian waters enabled us to gain insight into the ranging and residency pattern of the dolphin stranded in 2023 due to larynx strangulation with fishing net parts.

The smallscale codlet, Bregmaceros nectabanus Whitley, 1941, is a small gadiform fish native to the Indo-West Pacific and the Red Sea. It is considered non-indigenous in the Mediterranean Sea, with its first records appearing in the early 2000s. This paper reports the first confirmed occurrence of B. nectabanus in Montenegrin waters. The specimen was caught by beach seine in the interior of Boka Kotorska Bay at a depth of less than 20 m. Morphometric measurements were compared with existing Adriatic and Mediterranean records, revealing general consistency, although minor deviations were attributed to intraspecific variability, ontogeny, or ethanol-induced shrinkage. An updated overview of Mediterranean records from 2002 to 2024 is provided. While the overall distribution pattern supports a Lessepsian migration pathway, the occurrence of the species in areas of intensive maritime traffic suggests that secondary dispersal via ballast water may contribute to its spread. These findings extend the known range of B. nectabanus in the Adriatic Sea, indicating an ability to exploit shallow coastal environments. Further monitoring and genetic studies are recommended to clarify the mechanisms underlying its ongoing expansion.

Marine recreational fishing has significantly increased in recent years, especially in the Northern Adriatic Sea, where it accounts for equivalent up to 45% of artisanal fishery catches. Despite its relevance, few studies have investigated the potential impact of recreational fishing, particularly on vulnerable elasmobranch species, some of which are commercially targeted but face significant conservation problems. In this study, through online questionnaires administered to recreational fishers, we collected information on recreational fishing activities and their interaction with the most common demersal elasmobranchs along the western coast of the Northern Adriatic Sea. The responses revealed an intense fishing effort throughout the coastal area, especially around port entrances. The target species resulted primarily in those with high commercial value, while elasmobranchs are mostly bycatch, particularly Mustelus spp. Although 83% of fishers claimed to release them alive, the lack of studies on post-release survival rates makes it difficult to assess the impact of this fishing activity on elasmobranch populations.

The present study aims to describe Greek overseas fisheries from the beginning of the sector in the mid-20th century up to today. The Greek overseas fisheries expanded, from the northern African countries to the Atlantic and Indian Ocean, peaking in the 1970s. However, starting in the 1990s, the sector exhibited a sharp decline in landings and active vessels, which was caused by several issues, such as the increased territorial restrictions, high operational costs, unorganized market structures, and insufficient fish processing facilities. The historical evolution of the Greek overseas fisheries high- lights the need for improved market integration and smart policy interventions.

The study presents an exceptional number of records of the devil firefish Pterois miles along the Croatian coast. These records are based on 122 confirmed sightings of the species recorded between June 2024 and January 2025, providing evidence of a rapid and extensive expansion of the species in the eastern Adriatic waters. Most records originated from citizen science via direct reports of sightings, complemented by monitoring of social networks and online media platforms. The highest number of sightings was recorded around the islands of Lastovo and Vis, while the area around Dubrovnik had the highest number of sightings along the mainland coast. The majority of individuals (72.7%) were sighted within the first 15 meters of depth, with most individuals estimated to be 15 cm or smaller in length. No correlations between depths and lengths of individuals, as well as between time and latitude of sighting were detected. Most sightings occurred during diving activities, with a few involving captured specimens. The observed expansion is likely a result of larval transport via sea currents and subsequent settlement, as the pattern of records aligns with general circulation patterns along the eastern Adriatic coast. Given the species’ biological traits, which facilitate rapid and extensive establishment in invaded areas, this expansion poses certain ecological risks, particularly in key coastal habitats that host ecologically and economically important fish species. We encourage targeted removal strategies, particularly in ecologically significant areas such as Marine Protected Areas (MPAs), commercialization of the species and reduction of fishing pressure on natural predators as mitigation measures.

This paper presents an assessment of the amount, composition and spatial distribution of seafloor marine litter in the southern part of the Adriatic Sea (GSA 18). Surveys were performed during a six-year period (2019-2024) from 24 hauls. Sampling was carried out using a bottom trawl during regular fishing activities (Fishing for Litter - FFL). Seafloor marine litter was classified into nine main categories (plastic, metal, rubber, cardboard/paper, textile/natural fibres, glass/ceramics, processed wood, and two categories of unclassified waste) in the laboratory of the Institute of Marine Biology, Kotor. The total average density of collected litter was 260.89 items/km2. The highest concentration of marine litter was determined in the Boka Kotorska Bay area, near the shoreline, at a depth range of 35-40 metres with an average density of 597.39 items/km2. The lowest value was recorded in the open part of the Montenegrin coast at depths of between 60 and 120 metres (148.74 items/km2). The highest concentration of marine litter near the coast is a consequence of increasingly intensive urbanisation, river inflows and the hydrological characteristics of the area. Plastic represents the dominant category in terms of the number of items, followed by metal and textiles/natural fibres. Marine litter related to fishing activities accounted for 3.34 % of the total litter collected on the seafloor.

In this study, the feeding habits of seven pelagic forage fish species inhabiting the Adriatic Sea, were evaluated by applying the stomach content analysis. Each month from June 2023 till September 2024 all biological samples were collected along the eastern Adriatic by commercial purse seiner “srdelara”. A total of 742 stomach samples were analysed. Small pelagic species such as sardine (Sardina pilchardus (Walbaum, 1792)), anchovy (Engraulis encrasicolus (Linnaeus, 1758)) and round sardinella (Sardinella aurita Valenciennes, 1847) primarily consumed copepods, while medium pelagic species including Atlantic horse mackerel (Trachurus trachurus (Linnaeus, 1758)), Mediterranean horse mackerel (Trachurus mediterraneus (Steindachner, 1868)), Atlantic chub mackerel (Scomber colias Gmelin, 1789), and bogue (Boops boops (Linnaeus, 1758)) favoured larger prey such as mysids, euphausids, and decapod larvae. Seasonal variations were observed, with copepods dominating diets during warmer months and larger prey items during the colder part of the year. Lower differences between small and medium species diets occurred in warmer months, linked to increased zooplankton availability in the investigated area. The results obtained in this study indicated potential competition among the observed pelagic species, particularly under resource-limited conditions, highlighting the necessity of adopting an ecosystem-based approach in fisheries management. Such an approach would undoubtedly ensure the sustainable exploitation of these renewable resources in the Adriatic Sea.

In the circalittoral zone of the Mediterranean Sea, the nursehound Scyliorhinus stellaris lays eggs in spawning areas located at depths between 25 and 50 m in the red gorgonian meadows. Given the evident decline of the nursehound population in the Mediterranean and its high vulnerability, investigating spawning and potential nursery areas is crucial for the conservation of this species. Using non-invasive techniques such as diving activities with the help of R.O.V. (Remote Operated Vehicle), spawning areas have been identified along the Tuscany coast in Italy. In addition, B.R.U.V.S. (Baited Remote Underwater Video System) was used as an auxiliary method to diving activities in order to record the presence of nursehound individuals. Between 2018 and 2024 (except for 2022), 66 eggs were spotted around Monte Argentario peninsula on the Argentarola Island, Grotta del Corallo, Cala Grande, Capo D’Uomo, Cala della Maddalena and around Giannutri Island in Punta Scaletta. The highest number of eggs was observed around the Argentarola Island, Grotta del Corallo, and Cala Grande, both daily and during the entire study period, which suggests that these three sites represent spawning areas. Furthermore, two adult nursehound individuals have also been sighted near Argentarola Island, suggesting this site could represent a potential nursery area. Further data will be collected in these sites through more in-depth investigation in order to understand spatial distribution patterns, relative abundance, population estimates and behavior of this species along the Tuscany coast.

The polyopisthocotylan Microcotyle erythrini was first described from the common pandora (Pagellus erythrinus) collected off Brest, Northeast Atlantic, and subsequently recorded from various sparid hosts across the Mediterranean. Recent studies combining morphometric and molecular data resolved this complex into distinct species, including M. isyebi from Boops boops and M. whittingtoni from Dentex dentex. Here, we investigate Microcotyle from Pagrus pagrus off Tunisia (Western Mediterranean), combining morphological and molecular barcodes (28S rRNA and cox1). The cox1 sequence divergence between Microcotyle from P. pagrus off Tunisia and M. erythrini sensu stricto from P. erythrinus in the Mediterranean was 0-3 %, suggesting the presence of a single species. Newly generated cox1 sequences clustered with high support within the M. erythrini sensu stricto clade reported from P. erythrinus in France and Spain and P. pagrus in Spain and Algeria. Phylogenetic analyses based on partial 28S rDNA sequences corroborated this, as the newly generated 28S sequences of M. erythrini from P. pagrus off Tunisia clustered alongside isolates from P. pagrus and P. erythrinus across the Western Mediterranean. We also provide novel morphometric and anatomical data for M. erythrini sensu lato based on Adriatic specimens (Montenegro) and discuss host specificity patterns in Microcotyle spp. from the Mediterranean. These findings emphasize the importance of comprehensive taxonomic revisions and highlight the complexity of Microcotyle species associated with sparid hosts in the Mediterranean.

Native to the Indo-Pacific region, the sacoglossan species complex Elysia cf. marginata-grandifolia is considered a Lessepsian migrant and an alien species in the Mediterranean Sea, following its first record along the coast of Turkey in 2001, and consecutive observations in the area. Subsequent studies have reported its presence in the Levantine basin along the coasts of Turkey, Israel, Lebanon, and Cyprus, with uncertainties around its taxonomic assignment. This paper highlights the presence of two alien Elysia species included in these reports, separated now for the first time. We also present new findings of Elysia sp. 2’s range, marking its first occurrence in the Aegean Sea in July 2024 along the coast of Lipsi Island, Greece. This record represents the species’ westernmost distribution in the Mediterranean basin, highlighting a potential ongoing range expansion. Although further examinations in the region would be needed to fully ascertain whether an established population is present in the Aegean Sea, this report demonstrates the importance of continuous monitoring in the early detection of the presence of alien and invasive species, to inform conservation and management strategies.