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This study reports the first attempt to quantitatively describe a Dendrophyllia ramea population on the Apollo bank (Ionian Sea), revealed in summer 2021 through a remotely operated vehicle (ROV) survey. The habitat description, bathymetric distribution, population density, and structure of the species were assessed by image analysis. A well-developed population of D. ramea, located on boulders on a sedimentary plateau at 70–80 m depth, was observed. The density ranged on average between 0.17 ± 0.04 and 0.8 ± 2.4 colonies m–2 with dense patches up to 8 colonies m–2. The population consisted primarily of many isolated single corallites and colonies of various sizes, some of which reached a maximum height of more than 40 cm. Deepwater fishing activities, primarily longline fishing, negatively affected this species. The newly collected data add knowledge about this vulnerable scleractinian coral. The documented negative effect of fishing activities on vulnerable marine ecosystem (VME) species further highlights the need for urgent conservation measures.

The Mediterranean Sea supports high levels of biodiversity and complexity but is facing increasing human pressures, so that strategies to protect and recover its ecosystems must be a priority in environmental policies. Benthic cartography represents the first step of marine spatial planning for the proper management and protection of our sea. Univocal habitat classification systems are thus needed to map, monitor, and inventory marine habitats, and to guarantee common and shared frames for a harmonized interpretation of the Mediterranean habitat types. In this paper we reviewed the existing classification systems of marine benthic habitats, to discuss the process of revision and updating of one of the first system developed under the Barcelona Convention (BC) in 1998 and adopted by all the Mediterranean countries. The BC classification was revised including the new habitats discovered in the last 30 years, and consistently with the criteria used to revise the EUropean Nature Information System (EUNIS), which is a comprehensive pan-European system for habitat identification. The updated BC classification is hierarchical with 5 levels, which allows representing the most suitable habitat level with respect to the restitution scale of the map. Each habitat is univocally identified by an alpha-numeric code, name and general description following the bionomic approach traditionally adopted in the Mediterranean benthic cartography since the late nineteen century. The new BC classification lists 128 main habitats up to the level 4, which may also contain sub-habitats at the level 5, i.e. associations and facies, totalising 394 habitat types (54% of new habitats with respect to the first BC classification). The updated BC classification system has been used for the selection of reference marine habitats that support two fundamental processes of environmental management: i) identification of Specially Marine Protected Areas according to the SPA/BD Protocol of Barcelona Convention; ii) selection of habitats to be monitored, as requested by the Integrated Monitoring and Assessment Programme and the European Directives (e.g., Water Framework and Marine Strategy). The new list of reference habitats, selected because of their high ecological and conservation value, contains 267 habitats, corresponding to 68% of the total habitats listed in the updated BC classification.

39 pages, 6 figures, 2 tables, This paper presents major gaps and challenges for implementing the UN Decade of Ocean Science for Sustainable Development (2021-2030) in the Mediterranean region. The authors make recommendations on the scientific knowledge needs and co-design actions identified during two consultations, part of the Decade preparatory-phase, framing them in the Mediterranean Sea’s unique environmental and socio-economic perspectives. According to the ‘Mediterranean State of the Environment and Development Report 2020’ by the United Nations Environment Programme Mediterranean Action Plan and despite notable progress, the Mediterranean region is not on track to achieve and fully implement the Sustainable Development Goals of Agenda 2030. Key factors are the cumulative effect of multiple human-induced pressures that threaten the ecosystem resources and services in the global change scenario. The basin, identified as a climate change vulnerability hotspot, is exposed to pollution and rising impacts of climate change. This affects mainly the coastal zones, at increasing risk of extreme events and their negative effects of unsustainable management of key economic assets. Transitioning to a sustainable blue economy is the key for the marine environment’s health and the nourishment of future generations. This challenging context, offering the opportunity of enhancing the knowledge to define science-based measures as well as narrowing the gaps between the Northen and Southern shores, calls for a joint (re)action. The paper reviews the state of the art of Mediterranean Sea science knowledge, sets of trends, capacity development needs, specific challenges, and recommendations for each Decade’s societal outcome. In the conclusions, the proposal for a Mediterranean regional programme in the framework of the Ocean Decade is addressed. The core objective relies on integrating and improving the existing ocean-knowledge, Ocean Literacy, and ocean observing capacities building on international cooperation to reach the “Mediterranean Sea that we want”, With the institutional support of the ‘Severo OchoaCentre of Excellence’ accreditation (CEX2019-000928-S)

Demersal fish assemblages on the rocky bottoms of the Aeolian Archipelago were investigated using a Remotely Operated Vehicle (ROV) within the framework of research activities aimed at drawing up the zoning proposal of a new Italian national marine protected area. Visual assessments were conducted around the seven main islands by means of a total of 36 ROV transects. Video material was divided into 3 parts belonging to 3 Archipelago sectors (Western, Central and Eastern) and into 3 depth ranges (20-50, 51-120, 121-190). Thirty taxa of teleosts (29 species and 1 genus) belonging to 16 families were recorded. The assemblages were numerically dominated by some schooling fishes, such as Anthias anthias, Callanthias ruber and Chromis chromis, which exhibited a depth related partitioning of space, and three non-gregarious species, i.e. Serranus cabrilla, Coris julis and Lappanella fasciata. In terms of species composition, the assemblages observed in the sectors of the Archipelago largely overlapped. No significant sector-related differences were detected in fish species richness, diversity and total density. Species composition and the investigated assemblage parameters were significantly affected by depth. The pattern of variation in species richness among depth ranges changed depending on the archipelago sectors. No significant interaction between the factors depth range and sector was observed for species diversity and total density. Diversity values at 20-50 and 121-190 m depth were similar and significantly higher than that at 51-120 m depth. Fish total density showed a clear decreasing trend with increasing depth, though significant differences were detected between the 20-50 and 51-120 depth layers and the deepest one. Overall, the demersal fish assemblage of the Aeolian Archipelago was poorly diversified and depleted, most likely due to overfishing. This information highlighted the importance of the adoption of specific measures aimed at the recovery of overexploited resources and the restoration of the whole marine ecosystems.

The Mediterranean Sea is one of the most polluted marine basins and currently serves as a hotspot for marine litter. The seafloor represents the ultimate sink for most litter worldwide. Nevertheless, the knowledge about litter distribution and its interactions with benthic organisms in deep water is poorly understood. In 2018, we investigated spatial patterns of macro- and micro-litter distribution, and their effects on benthic communities in the Ligurian Sea. An oceanographic survey was carried out with a remotely operated vehicle and a multibeam echosounder on seven seamounts and canyons, at depths ranging from 350 to 2200 m. High litter accumulations were discovered at the mouth of the Monaco canyon, where estimated densities of up to 3.8 × 104 items km−2 were found at 2200 m depth. The highest abundance of urban litter items was found on the soft substrate, at the bottom of the deeper parts of the submarine canyons, which seem to act as conduits carrying litter from the shelf towards deeper areas. In contrast, fishing-related items were most abundant in the upper layer of the seamounts (300–600 m depths). Furthermore, more than 10% of the observed deep gorgonian colonies were entangled by lost longlines, indicating the detrimental effects of this fishing gear on benthic habitats. The discovery of new litter hotspots and the evaluation of how deep-sea species interact with litter contribute to increasing the knowledge about litter distribution and its effects on the deep ecosystem of the Mediterranean basin. All the observations recorded in this study showed substantial and irreversible changes in the deep and remote areas of marine environments, and these changes were found to be caused by humans. Our findings further stress the need for urgent and specific measures for the management of deep-sea pollution and the reduction of litter inputs in the environment.

Scleractinian cold-water corals (CWCs) are among the main habitat engineers of the deep Mediterranean Sea, hosting a high diversity of species and playing a significant ecological role. In the last two decades, many new living scleractinian CWC sites throughout the Mediterranean Basin have been recorded and their distribution has been updated. In the summer of 2018, new scleractinian CWC assemblages were discovered by means of remotely operated vehicle (ROV) and multibeam echosounder (MBES) surveys on the Aceste–Tiberio seamount and Marettimo bank in the southern Tyrrhenian Sea, at depths ranging from 240 to 310 m. In the explored areas, megabenthic communities were dominated by habitat-forming species, some of which have never been reported before on these submarine structures. Healthy patches of Madrepora oculata and Desmophyllum pertusum, together with the solitary coral D. dianthus, were found on rocky pinnacles between inclined silted bottoms, as well as on a wreck. Deep-water fishing activities, mainly longline fishing, negatively affected these communities, particularly coral species. The discovery of these new sites adds new knowledge about the distribution of scleractinian CWCs in the Mediterranean Sea. Moreover, the documented negative effect of fishing activities on CWC species further stresses the need for urgent and specific conservation measures. In this regard, the co-occurrence of several long-lived, slow-growing, and vulnerable species on these seamounts and banks supports the establishment of specific marine protected areas [i.e., offshore Natura 2000 sites, in accordance with the Habitats Directive (92/43/EEC) - Habitat 1170 - Reefs].

Biodiversity of coral forests and occurrence of Derelict Fishing Gears (DFGs) have been assessed in canyon systems of the western Ligurian Sea (Dramont, Monaco, Bordighera, Arma di Taggia and Bergeggi) exposed to different anthropic pressures. Arborescent cnidarians were elected as representative species due to their role as structuring organisms and their vulnerability to DFGs damage; hence, their occurrence, density and distribution were correlated to the presence of DFGs. The canyon systems were mapped using a Multibeam Echo Sounder and visually surveyed by means of a Remotely Operated Vehicle between 20 and 445 m depth. With the exception of the Bergeggi canyon system, all sites host rich assemblages of structuring anthozoans, accounting for more than 2000 colonies belonging to 11 species, predominantly Eunicella cavolinii, Paramuricea clavata, Corallium rubrum, Dendrophyllia cornigera, and E. verrucosa. We noticed that the large structuring gorgonians were affected most, with a high number of entangled colonies. DFGs represent 85% of the marine litter found, and are the most serious threat to resident sessile communities, most noticeably in the eastern canyons. Ports, size and fishing effort of local fleets, and socio-economical differences in the fishing activities, strongly influence the fishing footprints. Our study further confirms the role of submarine canyons as site of high coral biodiversity and vulnerability to the mechanical damages by fishing-related littering, calling for adequate management measures to reduce fishery pressure and concomitant DFGs discharge.

The Natura 2000 (N2k) network is an important site-based protection tool for the protection of biodiversity in Europe. However, for highly mobile and adaptable marine species, such a tool might not be the most effective way to achieve conservation objectives, unless this includes a broader consideration of the direct threats to these species throughout their range. Considering that the N2k network requires that a ‘significant proportion’ of 60% of the population be under protection, this creates a challenge for the conservation of these wide-ranging species. This paper reviews the efficacy of the N2k network as it is presently implemented within the Adriatic Sea for the conservation of two highly mobile marine species - the common bottlenose dolphin and the loggerhead turtle. In particular, it considers the appropriateness of the current Sites of Community Importance (SCIs) in the region and the relevance of the existing marine N2k network for the conservation of these species. It provides new insights on the approach used to evaluate SCI designations highlighting important weaknesses in the system, including threat identification after SCI designation, and the relevance of SCI size in relation to management commitments. Data from two basin-wide aerial surveys were used to define areas of relative high density of these species, in comparison to other areas in the basin. Given the ambitious 60% conservation target of the N2k network, analysis shows that site-based protection tools are unlikely to be sufficient to protect a ‘significant proportion’ of either species, unless very large areas are designated as SCIs. However, given that the main threats known to affect these species in this region (i.e. fishery bycatch and seismic surveys) are present throughout the basin, these large SCIs would still have limited conservation success without implementing other wide-scale mitigation measures. For these two species, the Member States and the European Union authorities should give higher priority to the implementation of another pillar of the Habitats Directive, mitigating accidental catches in fishing gear and other human-induced mortalities. This should take into consideration the full effects of these mortalities on the populations of these two species through regular transboundary monitoring programs.

The fish assemblages of the coastal area of the promontory of Cape Milazzo (Italy, Central Mediterranean), which has been recently designated by the Italian Law to become a national marine protected area (MPA), were characterized by visual censuses carried out over different habitats (rocky algal reef, Posidonia oceanica meadow and soft bottom) and depth ranges (0-3, 4-7, 12-16 and 24-30 m) to identify areas of major concern for the MPA zoning. The study area was divided into 6 sectors to assess spatial-related differences in the assemblage parameters, such as species composition and richness, and the size structure of species of recreational (e.g. SCUBA diving) interest. Fifty-eight taxa (56 species and 2 genera) and 20 families of fishes were totally recorded. Species composition was significantly affected by habitat and depth, whereas no significant changes were detected among sectors. Conversely, species richness and total density of fish showed no significant differences among sectors, habitat types and depth ranges. The majority of species of recreational value was recorded only off the northwestern part of the promontory. The implementation of fishing ban in such an area, characterized by the presence of a rocky bank, would contribute to the recovery of populations of some emblematic species (e.g. groupers and other large predator) and to the enhancement of environmentally sustainable activities such as scuba diving. Throughout the investigated area and, especially, in the eastern and southwestern coasts of the promontory, several species were almost exclusively represented by small and medium sized individuals, a likely consequence of an intense fishing pressure.

The distribution of gold coral Savalia savaglia is modified on the basis of bibliographic information and recent occurrence data, collected using a ROV (Remotely Operated Vehicle) and SCUBA divers. The species is long-lived, rare and has been exploited in the past by divers for collection purposes. S. savaglia is listed in Annex II of the SPA/BD Protocol of the Barcelona Convention and has a wider distribution than previously thought, including both the Mediterranean Sea and the Atlantic Ocean. Our results highlighted that specimens mainly live at a depth range of 15-90 m, but may reach as deep as 900 m in the Mediterranean Sea. This species can form monospecific facies of hundreds of colonies, as observed in Montenegro (Adriatic Sea), between 10 and 20 m, and in the Canary Islands, at a depth range of 27-70 m. Recent data highlighted numerous cases of specimens that were endangered by lost fishing gear, which exposed this species to further threats. Considering its longevity and structural role, it is urgent to develop an effective protection measure for S. savaglia, thereby increasing research efforts and implementing protection areas for this species.

a b s t r a c t In this study we assess the existence of gradients of abundance (density and biomass) of the sea breams Diplodus puntazzo, Diplodus sargus and Diplodus vulgaris across the boundaries of the Portofino MPA (NW Mediterranean) in order to evaluate reserve effect and to provide evidence of spillover. Fish were visually censused in shallow rocky habitat (4-7 m depth) at replicate sites within the different MPA zones and in adjacent unprotected areas. Higher values of sea breams size, density and biomass were usually observed inside MPA compared to unprotected areas, likely due to the enforcement of protection. We found evidence of negative gradients of sea bream density and biomass across the MPA boundaries, although shape and steepness of gradients changed depending on species, sampling time and boundary orientation. Fish density and biomass decreased abruptly just 100 m outside the MPA and remained close to zero off the western boundary. A partial recovery in fish density was recorded eastward, about 1 km apart from the MPA boundary. Overall, our results were consistent with the presence of a moderate fish spillover, considering that a high fishing effort close to the MPA boundaries could have prevented any potential increase in abundance just outside the MPA. © 2011 Elsevier B.V. All rights reserved.

The Ligurian Sea is a deep basin in the northernmost sector of the western Mediterranean which shows peculiar hydrodynamic and meteo-oceanographic features. The coasts of the Ligurian Sea are among the most urbanised and industrialised along the Italian coastline: the main causes of disturbance being littoral urban development and harbour activities, the building of littoral rail- and highways, and the presence of several polluted discharges. This review, by evaluating the huge scientific output published in the last three decades, describes and discusses the most important geological, hydrological and biological characteristics of the Ligurian Sea. We show that this regional sea has largely been investigated in terms of its geological and structural evolution, as well as in terms of the sedimentation dynamics of the littoral and deep bottoms, with particular attention to the sedimentation balance of the beaches and their erosive processes. We report that the prevalent hydrodynamic and meteo-oceanographic conditions favour a continuous exchange of coastal water masses, and that the seasonal and interannual dynamics of water masses can effects the local climate, with direct and indirect consequences on fish and benthic communities documented in the last decade. We stress that although recent studies offer good knowledge of the distribution of coastal benthic communities, only scant information is available for the whole continental shelf, the submarine canyons and the rocky bathyal bottoms. Our meta-analysis reveals that significant fishing activities are monitored, but also that certain sectors of the biological resource are suffering, and suggests the set up of appropriate management measures. The Ligurian Sea hosts a number of Marine Protected Areas (MPAs) of high relevance, while the institution of the Whale Sanctuary completes the protection policy of the Regione Liguria. Our meta-analysis points out the need for long-term studies, based primarily on the analysis of those areas of the Ligurian Sea that have been little investigated to date. Finally, only properly addressed studies, using experimental approaches and along appropriate spatial and temporal scales, might allow us to understand the functioning of the Ligurian marine ecosystems, evaluate their health conditions and the dynamics of the main variables that affect the distribution of the single species (including species of high economic value) and benthic communities.

The main objective of this study is to improve the knowledge of the coastal fish assemblage of ‘Cinque Terre’ Italian national Marine Protected Area (Ligurian Sea), focusing on the characterization of the fish fauna in the core zone A (no entry–no take). The study relates to the main sea-bottom types and bathymetric ranges, and evaluates the effect of the protection on fish abundance and size composition in this 5-yr-old MPA. Field activities were carried out in 2003 by means of visual census techniques. In the A zone, fish-assemblage composition are strictly related to depth and sea-bottom type. Recorded data did not permit detection of a clear reserve effect on fish fauna, probably due to the recent institution of the MPA. Several significant differences were detected only considering the size-class composition of target species.

In July 2010 and August 2011 a subadult and an adult porbeagle shark Lamna nasus were respectively caught as by-catch by an artisanal fishery boat using a gill net in the central Adriatic Sea. The specimens, a mature 200 and a maturing 150 cm total length male, were photorecorded, measured and identified on the basis of meristic traits. Such two occurrences are discussed in the context of recent and historical information available on the presence of this species in the Mediterranean Sea. Overall, data confirmed on the one hand the rarity of the porbeagle shark in the Adriatic Sea also, and, on the other hand, they suggested some relation between the density of the findings for this species and the presence of a pit zone in the central part of the Adriatic Sea.