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Ecosystem based management requires assessment of human activities and generated pressures that cause physical disturbance and loss of the seabed within the Mediterranean, also accounting for the strength of their interaction. To support the implementation of Descriptor 6 of the Marine Strategy Framework Directive (MSFD), the present work aimed at testing the applicability of an exposure-effect methodology and harmonizing - across countries sharing the same marine waters - the identification of the MSFD key physical pressures on benthic habitats and their relative importance at different spatial scales (national, subregional, regional) in the Mediterranean Sea. The methodology uses 24 MSFD relevant human activities, five physical pressures, and 13 Broad Habitat Types (BHT). Τhe links between human activities, physical pressures and the different MSFD Broad Habitat Types affected are identified and scored using three criteria; namely Spatial Extent, Frequency of Occurrence, and Degree of Impact. The methodology assesses the risk of pressures in a semi-quantitative way, integrating both quantitative (data) and qualitative (expert judgement) information, where quantitative data is not available, and allows the ranking of the physical pressures affecting the seafloor. The methodology was applied in the marine waters of Italy, Slovenia, Croatia and Greece. Abrasion (e.g., related to fishing or boating) and sealing (e.g., caused by structures) were ranked as top pressures; the former is widespread over different BHTs, in a persistent manner and presents intense impacts; the latter appears locally, at specific sites, and persistently, generating an acute impact. According to the results, the infralittoral and circalittoral habitats are those most affected by physical pressures. The identification of major pressures can assist considerably towards the elimination or mitigation of the impacts through actions on the human activities, as it enables the prioritisation of tailor-made measures to achieve or maintain the Good Environmental Status (GES) in the region. • Screening and assessing physical pressures affecting seafloor integrity. • Testing an exposure-effect methodology relevant to MSFD Descriptor 6. • Addressing key physical pressures on benthic habitats in a harmonised way. • Assisting decision makers in prioritizing management actions for the seafloor. • Ecosystem-based management in the Mediterranean region. [ABSTRACT FROM AUTHOR]

Conservation of fish habitat requires a deeper knowledge of how species distribution patterns are related to environmental factors. Habitat suitability modelling is an essential tool to quantify species’ realised niches and understand species-environment relationships. Cephalopods are important players in the marine food web and a significant resource for fisheries; they are also very sensitive to environmental changes. Here a time series of fishery-independent data (1998–2011) was used to construct habitat suitability models and investigate the influence of environmental variables on four commercial cephalopods: Todaropsis eblanae , Illex coindetii , Eledone moschata and Eledone cirrhosa , in the central Mediterranean Sea. The main environmental predictors of cephalopod habitat suitability were depth, seafloor morphology, chlorophyll-a concentration, sea surface temperature and surface salinity. Predictive maps highlighted contrasting habitat selection amongst species. This study identifies areas where the important commercial species of cephalopods are concentrated and provides significant information for a future spatial based approach to fisheries management in the Mediterranean Sea. [ABSTRACT FROM AUTHOR]

Abundance, composition, and distribution of macro-litter found on the seafloor of the Strait of Sicily between 10 and 800 m depth has been studied using data collected by bottom trawl surveys MEDITS from 2015 to 2019. Three waste categories based on the items use were considered: single-use, fishing-related and generic-use. Over 600 sampling sites, just 14% of these were litter-free. The five-years average density of seafloor litter was 79.6 items/km2 and ranged between 46.8 in 2019 and 118.1 items/km2 in 2015. The predominant waste type was plastic (58% of all items). Regardless of material type, single-use items were a dominant (60% of items) and widespread (79% of hauls) fraction of litter with a mean density of 48.4 items/km2. Fishing-related items accounted for 12% of total litter items. Percentage of dirty hauls and litter density increased with depth. Analysis of the relation density-depth indicates a progressive increase of litter density beyond depth values situated within the interval 234–477 m depending on the litter category. A significant decrease in litter density by categories was observed over the period. Patterns of spatial distribution at the higher depths (200–80 0m) resulted stable over the years. Density hotspots of fishing-related items were found where the fishing activity that uses fish aggregating devices (FADs) is practised and in the proximity of rocky banks. Single-use and generic-use objects densities were greater on the seafloor along main maritime routes than other areas. Comparisons between the percentage of hauls littered with anthropic waste from the mid-1990s against those in 2018–19 highlighted an increase of about 10.8% and 15.3% for single-use items and fishing-related items respectively, and a decrease of 18.6% for generic-use items. This study provides a snapshot of the current situation of littering in the central Mediterranean Sea and represents a solid baseline against which the effectiveness of current and future mitigation strategies of the litter impact on marine environment can be measured. Image 1 • The density of seafloor macro-litter in the Strait of Sicily increases with depth. • Single-use and generic-use items accumulate along shipping routes. • Fishing-related items are associated with specific fishing areas. • The occurrence of litter is higher than in the '90s but decreases from 2015 to 2019. • Baseline information useful for mitigation policies of seafloor macro-litter. Main findings: Higher density of litter distribution at deeper bottoms. Single-use and generic-use items accumulate along main shipping routes; fishing-related items are associated with specific fishing activities. [ABSTRACT FROM AUTHOR]

Abstract: Generalised Linear Models, combined with a Geographic Information System, were used to map the habitats of ten demersal elasmobranch taxa (five skates, four sharks and a stingray) in the eastern English Channel, based on an annual fishery-independent bottom trawl survey conducted each October, and covering 21years. Habitat models showing mean density levels were developed for the most frequently occurring species, whilst binomial occurrence habitat models were built for less frequent species. The main predictors of elasmobranch habitats in the eastern English Channel were depth, bed shear stress and salinity, followed by seabed sediment type and temperature. Habitat maps highlighted contrasting habitat utilisation across species. Raja clavata, and to a lesser extent Scyliorhinus canicula, showed ontogenetic differences in habitat utilisation, with early life history stages found in shallow coastal waters, sheltered from strong tidal currents and typically with softer sediments. Spatial segregation by sex was also evident for S. canicula, with females found at higher densities on some harder grounds in the study area. An improved knowledge of habitat utilisation by elasmobranchs (particularly for important life history stages and all seasons) is required if spatial management is to be considered for these species. [Copyright &y& Elsevier]