This study evaluates the fishing pressure exerted by the most common recreational and professional, small-scale fishing practices on vulnerable target and bycatch species in coastal and offshore waters of the western Mediterranean. By combining multiple data sources, we assembled a unique dataset on catches at multiple sites in these areas by recreational (RF) and small-scale fisheries (SSF), covering the period from 1997 to 2015. Furthermore, a framework with which to identify the vulnerable species among all the species caught is provided; it is based on the IUCN Red List, international conventions for the protection of flora and fauna, the Habitats Directive and the intrinsic vulnerability index of marine fish. Overall, about a quarter of exploited species targeted by SSF and RF in coastal waters were vulnerable, making up nearly 50% of the total SSF catch and nearly 20% of the total recreational catch. In offshore waters, 100% of the RF and SSF catch was made up of vulnerable species. Among the species caught as bycatch in both areas by SSF and RF, there was a total of 27 vulnerable vertebrate species, which included birds, cetaceans, elasmobranchs and sea turtles. Our results highlight the need to differentiate between different fishing methods or gears when studying the fishing impacts on vulnerable species. The results also indicate that, although RF and SSF are often considered to have a relatively low ecological impact, a range of different fishing methods are affecting vulnerable species in coastal or offshore waters in the western Mediterranean Sea, be they targeted or taken unintentionally as bycatch.

The present study provides updated information on the occurrence, abundance and biomass distribution patterns and length frequencies of Merluccius merluccius in the Mediterranean Sea, by analysing a time series of data from the Mediterranean International Trawl Surveys (MEDITS) from 1994 to 2015. The highest values of abundance and biomass were observed in the Sardinian Seas. The use of a generalized additive model, in which standardized biomass indices (kg km^–2) were analysed as a function of environmental variables, explained how ecological factors could affect the spatio-temporal distribution of European hake biomass in the basin. High biomass levels predicted by the model were observed especially at 200 m depth and between 14°C and 18°C, highlighting the preference of the species for colder waters. A strong reduction of biomass was observed since the year 2009, probably due to the strengthening of the seasonal thermocline that had greatly reduced the availability of food. The general decrease in biomass of several stocks of anchovy and sardine, preys of European hake, might be indirectly connected to the decreasing biomass detected in the present study. The length analysis shows median values lower than 200 mm total length of most of the investigated areas.

This study aimed to test the effectiveness of a “guarding net”, a device placed at the bottom of a trammel net, for reducing unwanted catches in the caramote prawn trammel net fishery of the Ligurian Sea. This specialized and profitable fishery is affected by unwanted catches that generate high discard rates and damage to the nets, with environmental impacts and costs for fishermen. The experimental study consisted in comparing the catches of a standard trammel net (STN) with those of two “experimental” trammel nets, e.g. STNs provided with a guarding net of 19 cm (TGN20) and 24 cm height (TGN25), respectively. The guarding net, a strip of gillnet placed at the bottom of the net, can be considered a by-catch reducer device (BRD). Some fishermen of the investigated fishery have been using this device for several years. The results of the 15 experimental fishing trials performed from June to July 2016 indicate that the guarding nets significantly reduce discards (e.g. crabs and other invertebrates); the biomass of the unwanted species caught was 75% lower than that produced by the STN. The catch rates of the target species obtained with TGN20 and TGN25 were also significantly lower than those of the STN, though of a lesser amount. Nonetheless, this economic loss can be compensated by the decrease in sorting time and material and labour costs that can be achieved using the guarding net.

The time series of elasmobranch catch rates off the Tuscany coasts (NW Mediterranean) were investigated by means of min/max auto-correlation factor analysis in order to estimate variations in population abundance and evaluate the influence of environmental and anthropogenic factors. The analyses highlighted a general decreasing trend in the catch rates of sharks and skates from 1961 to the mid-1990s, mainly influenced by the increase in fishing effort. Since the 1990s, the EU Common Fishery Policy for the Mediterranean has promoted the reduction of fishing fleets through incentives to vessel demolition. The Porto S. Stefano trawl fleet has decreased by about 50%, leading to a decrease in fishing effort which seemed to be the most relevant factor affecting the increasing trend shown by the catch rates of Galeus melastomus, Scyliorhinus canicula and skates from 1991 to 2009. The elasmobranch assemblage did not undergo major shifts but the weighted frequency of occurrence shows that elasmobranchs were more frequent in the past. Particular caution should be paid in interpreting the recent rebound of some species as an early sign of recovery: trawl survey data and landing data show that over the last 50 years elasmobranch fauna have undergone a drastic decline and that recent rebounds are still far from a recovery to historical levels.

The Mediterranean Sea has a long-lasting history of fishery exploitation that, together with other anthropogenic impacts, has led to declines in several marine organisms. In particular, elasmobranch populations have been severely impacted, with drastic decreases in abundance and species diversity. Based on their experience, fishers can provide information on marine species occurrence, abundance and behavioural traits on a long-term scale, therefore contributing to research on the poorly studied biological aspects of elusive or rare elasmobranch species. In this study, for the first time, the use of the Local Ecological Knowledge (LEK) of fishers was applied to study the behavioural traits of sharks, rays and skates in 12 FAO-GFCM geographical sub-areas (GSAs) of the Mediterranean Sea. This study found both new insight and proved the reliability of LEK-based catch seasonality, reflecting seasonal movements, by comparing LEK-based findings and available literature on five elasmobranch taxa (Mustelus spp., Squalus acanthias, Raja spp., Myliobatis aquila and Scyliorhinus stellaris) in the Adriatic Sea and 7 taxa (Mustelus spp., Raja spp., Prionace glauca, Scyliorhinus canicula, Torpedo spp., Pteroplatytrygon violacea and Isurus oxyrinchus) in the remaining Mediterranean GSAs. In addition, LEK provided new insights into a novel comprehensive representation of species aggregations (Mustelus spp., S. acanthias, M. aquila and S. canicula) in the sampled GSAs and supplied the first descriptions of the size, number of individuals and sex composition of the aggregations. When the limits and shortcomings of LEK-based research are considered, this methodology can be a complementary and cost-effective tool used to study elasmobranchs in either a data-poor scenario or a scenario in which a baseline is missing. LEK can also be useful for the evaluation and inclusion of fishers’ perceptions on bottom-up management and to provide important evidence for conservation plans.