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18 pages, 5 figures, 3 tables, supplementary information https://doi.org/10.1007/s11160-023-09787-2, N. norvegicus supports one of the most commercially-important fisheries in the Mediterranean, and there is considerable interest in developing non-invasive sampling stock assessment methods. Currently, stock assessments are conducted via trawling or by UnderWater TeleVision (UWTV) surveys with limited capacity to provide direct population data due to the burrowing behavior of the species. Here, we used acoustic telemetry to characterize the burrow emergence and movement patterns of N. norvegicus in relation to internal tides and inertial currents in deep-sea habitats of the northwestern Mediterranean. We deployed acoustic tags on 25 adults between May and June 2019, and collected up to 4 months of detection data from each tag. Tagged lobsters spent approximately 12% of their time in door-keeping (i.e., detections at burrow entrance with no displacements) but differences existed among the different behavioral rhythms identified. We observed that mixed day-night, tidal and inertial rhythms in field settings were similar to those observed in laboratory tests. The presence of mixed day-night and tidal periodicity poses the question of why N. norvegicus exhibits flexible responses to environmental cues other than photoperiod. It is possible that tidal regulation of locomotor activity could reduce energy expenditure in relation to hydrodynamic drag. Inertial periodicity occurs in animals with no clear burrowing-oriented activity (always present on the seabed). Possibly, inertial-related movements are the result of a disruption of the biological clock. Our results are discussed in the context of how burrow emergence rhythms may bias UWTV surveys and how novel in situ monitoring approaches address these biases, Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. Ministerio de Ciencia e Innovación, RESNEP (CTM2017-82991-C2-1-R), RESBIO (TEC2017-87861-R), PLOME (PLEC2021-007525/AEI/10.13039/501100011033), PhD-fellowship5642. (ref. PRE2021-099558) under the BITER project (PID2020-114732RBC-31),Antoni Sánchez-Márquez,Severo Ochoa Centre of Excellence (CEX2019-000928-S), LIFE programme, LIFE20 NAT/ES/001270 LIFE ECOREST, DAMIANOS CHATZIEVANGELOU, H2020 Marie Skłodowska-Curie Actions,893089, Ivan Masmitja

10 pages, 4 figures, 3 tables, supplementary material https://doi.org/10.1016/j.fishres.2022.106552.-- Data availability: Data will be made available on request, Discards represent a loss of natural resources and negatively affect the sustainability of fisheries. Information on discards, such as diversity and size of the species discarded is essential to better manage trawl fisheries. Thus, this study aims to gain knowledge on discards from the Catalan bottom trawl fisheries in the NW Mediterranean Sea to offer information needed for fisheries management. Discard ratios, species composition of discards and lengths of the discards were analyzed from data collected on board commercial trawlers, from November 2018 to December 2020 and analyzed by depth, zone, and season. Discard ratio varied among depths from 30.5% in the shallowest depth (20 – 70 m) to 14.3% in the deepest (400–700 m), with depth being the main factor determining the species composition of discards. This study also focused on the discards of six main commercial species, i.e. European hake (Merluccius merluccius), red mullet (Mullus barbatus), black-bellied angler (Lophius budegassa), poor cod (Trisopterus capelanus), deep-water pink shrimp (Parapenaeus longirostris) and Norway lobster (Nephrops norvegicus). The length at which 50% of individuals were discarded (L50d) was lower than the Length at First Maturity (LFM) and the Minimum Conservation Reference Size (MCRS) for the six species. These findings provide relevant information to comply with the Marine Strategy Framework Directive’s (EU Directive 2008/56/EC) ecosystem approach to fisheries and to evaluate the implementation of measures for fisheries’ best management practices, such as gear selectivity and spatial planning, This work was supported by the Catalan Institute for Ocean Governance Research (ICATMAR), trawl surveys were financed by European Maritime and Fisheries Fund (EMFF) and the Catalan General Directorate of Marine Policy and Sustainable Fisheries by projects PESCAT (ARP029/18/00003) and CGCAT (ARP140/20/000006). This work acknowledges the accreditation of the 'Severo Ochoa Center of Excellence' (CEX2019-000928-S)

16 pages, 4 figures, 2 tables, Increasing interest in the acquisition of biotic and abiotic resources from within the deep sea (e.g., fisheries, oil–gas extraction, and mining) urgently imposes the development of novel monitoring technologies, beyond the traditional vessel-assisted, time-consuming, high-cost sampling surveys. The implementation of permanent networks of seabed and water-column-cabled (fixed) and docked mobile platforms is presently enforced, to cooperatively measure biological features and environmental (physicochemical) parameters. Video and acoustic (i.e., optoacoustic) imaging are becoming central approaches for studying benthic fauna (e.g., quantifying species presence, behavior, and trophic interactions) in a remote, continuous, and prolonged fashion. Imaging is also being complemented by in situ environmental-DNA sequencing technologies, allowing the traceability of a wide range of organisms (including prokaryotes) beyond the reach of optoacoustic tools. Here, we describe the different fixed and mobile platforms of those benthic and pelagic monitoring networks, proposing at the same time an innovative roadmap for the automated computing of hierarchical ecological information on deep-sea ecosystems (i.e., from single species’ abundance and life traits to community composition, and overall biodiversity), This work was developed within the framework of the Tecnoterra (ICM-CSIC/UPC) and the following project activities: ARIM (Autonomous Robotic sea-floor Infrastructure for benthopelagic Monitoring; MartTERA ERA-Net Cofound), ARCHES (Autonomous Robotic Networks to Help Modern Societies; German Helmholtz Association), RESBIO (Grant TEC2017-87861-R; Ministerio de Ciencia, Innovación y Universidades), RESNEP (Grant CTM2017-82991-C2-1-R; Ministerio de Ciencia, Innovacion y Universidades), MERCES (Marine Ecosystem Restoration in Changing European Seas - GA No. 689518), and IDEM (Implementing the MSFD to the Deep Mediterranean Sea, GA No. 11.0661/2017/750680/SUB/ENV.C2)

12 pages, 7 figures, 1 table, supplementary data https://doi.org/10.1016/j.dsr.2021.103496, Ecological niche modelling is used in deep-sea research to investigate the environmental preferences and potential distribution of data-poor species. We present a mesoscale assessment of Mediterranean seascape suitability for the cold-water coral Lophelia pertusa (= Desmophyllum pertusum, Linnaeus, 1758). We estimated seascape suitability and uncertainty maps using an ensemble approach of three machine-learning algorithms (Generalized Boosting Model, Random Forest, Maximum Entropy) based on environmental predictors. Bathymetry, bathymetric slope and pH were the most important predictors for the models. Overall the models reached good to excellent performance, with a very reliable prediction of the most suitable areas. In the Mediterranean Sea, L. pertusa encounters environmental settings close to its physiological limits but, despite the highly variable quality of the Mediterranean seascape, we identified high suitability areas mostly along the upper slope and at submarine canyons of the Western and Central margins. The existing MPAs do not overlap with high suitability areas, and therefore L. pertusa is only protected at the deepest fringe of its potential distribution by the implementation of the bottom trawling exclusion beyond 1000 m depth. This seascape suitability assessment may assist future research, including high-resolution modelling targeting high-suitability areas, investigation on the resilience of L. pertusa populations and development of conservation actions, The first author was funded by a PhD grant from Fundação para a Ciência e Tecnologia (FCT) (SFRH/BD/92433/2013). [...] This study was partially funded by FCT/MCTES by the financial support to CESAM (UIDP/50017/2020+UIDB/50017/2020), through national funds. [...] With the funding support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S), of the Spanish Research Agency (AEI)

Investigadors i tècnics especialitzats presenten els conceptes de capacitat de càrrega de l’ecosistema, enfocament ecosistèmic, gestió adaptativa, cogovernança, i defineixen les directrius per a una protecció harmonitzada i efectiva, i uns usos sostenibles dels ecosistemes marins costaners. La Taula de Cogestió Marítima del Litoral del Baix Empordà promou que en el seu entorn marítim i costaner de ric patrimoni natural, sòcio-econòmicament molt dinàmic, i també molt sensible a causa del canvi climàtic, s’apliquin estratègies de gestió adaptativa, consensuades per tots els agents implicats, tot ajustant les activitats i les pressions sobre els ecosistemes amb la finalitat de preservar el bon estat ecològic dels hàbitats i les espècies.

30 pages, 7 figures, 4 tables, The megafauna of deep continental margin of the exclusive economic zone (EEZ) of Uruguay have been little studied. The present study includes deep-sea trawling operations and represents the first analysis in detail of the deep-sea community of decapod crustaceans. Cluster analysis of bottom trawl data indicated that benthic megafauna are grouped in four bathymetric ranges along the continental margin: A, 250 > 1100 m; B, 1100 > 2000 m; C, 2000 > 3000 m; and D, 3000–3800 m, while pelagic species are not grouped by depth strata. The decapod individuals belong to 79 different species from which 64% correspond to shrimps (suborder Dendrobranchiata and infraorder Caridea), and the third most important group corresponds to the infraorder Anomura (18%). From those, previously 67% were not reported off Uruguay and 47% in the southwestern Atlantic Ocean. The bathymetric range of the identified decapods was enlarged by 32%. Moreover, the frequency distribution of species occurrences was rare since 56% of the species were only sampled once, thus indicating that the decapod community of this area is still far unknown. The benthic species were also more diverse than the pelagic decapods, and their abundance and biomass were higher. The biomass of the decapod community was dominated by the geryonid crab, Chaceon notialis, mainly located in the shallowest depth strata (representing 97% of the total biomass). To detect possible changes in the structure, biomass, and diversity of benthic assemblages, we recommend the implementation of long-term monitoring programs in the continental slope off Uruguay before fishing or mining exploitation is developed

This chapter describes how a small fishing community in Mediterranean Spain has taken charge over the management of the local red shrimp fishery. In Catalonia, the deep-sea red shrimp (Aristeus antennatus) is the most important commercial species, targeted by trawler fleets located in the numerous harbours along the Costa Brava. In recent years, it has become increasingly obvious that the heavy exploitation of the shrimp populations is no longer sustainable. As they faced decreasing catches and overcapacity, the fishermen in one of the fishing communities, Palamos, joined up with marine scientists from Barcelona to discuss the crisis. Together, they developed a management plan to secure a sustainable fishery. In this chapter, we describe the inspiring story of a bottom-up management initiative and discusses the mix of factors that made it into a success.

13 pages, 2 figures, 2 tables, We aim to study the sea spider specimens collected from a deep cruise in the economic exploitation zone of Uruguay from 250 to 3800 m with the Marianne fishing vessel. We gather the information from deep-sea Uruguayan pycnogonids from literature together with the ones reported in a recent checklist of sea spiders present in Uruguayan waters published by Scarabino et al. (2019) and including some biogeographic considerations. This new cruise includes two new species for Uruguayan waters and a great enlarging new bathymetric distribution of an already identified species in the area

Este artículo contiene 12 páginas, 5 tablas, 8 figuras., [EN]Decapod crustacean fisheries play a crucial role on the northwestern Mediterranean coast due to their high commercial value. Although knowledge of larval ecology and recruitment dynamics of these species is essential to establish a sustainable fisheries management, they are still poorly known. In this paper, we describe the composition, abundance and distribution of decapod crustacean larvae in the submarine canyon off Blanes (northwestern Mediterranean Sea) during summer thermal stratification conditions. Samples were collected in September 2011 with a multi-net system and a 60-cm bongo net at 22 stations with bottom depths of between 100 and 1800 m. A total of 635 larvae from 60 genera were identified. The most relevant taxa were Aristeus antennatus (7.93 individuals/1000 m3), the family Sergestidae (7.24) and Alpheus glaber (6.78). These three taxa were dominant (>20% of total decapod larvae) at more than half of the stations. Decapod larval communities were found to be richer and more diverse at the canyon head, a finding which could be explained by the higher retention rates when compared with the upstream and downstream walls and the canyon axis.[ES]Las pesquerías de crustáceos decápodos juegan un papel crucial en la costa del Mediterráneo noroccidental debido a su alto valor comercial. Aunque la información sobre la ecología larvaria y las dinámicas de reclutamiento de estas especies es esencial para establecer una gestión sostenible de estas pesquerías, estos aspectos son aún poco conocidos. En este estudio, se describe la composición, abundancia y distribución de las larvas de crustáceos decápodos en el cañón submarino de Blanes (Mediterráneo noroccidental) durante las condiciones de estratificación térmica estival. Las muestras fueron tomadas en septiembre de 2011 con un sistema multi-red y una red bongo de 60 cm de diámetro en 22 estaciones con fondos de entre 100 y 1800 m de profundidad. Un total de 635 larvas de 60 géneros fueron identificadas. Los taxones más relevantes fueron Aristeus antennatus (7.93 individuos/1000 m3), la familia Sergestidae (7.24) y Alpheus glaber (6.78). Estos tres taxones fueron dominantes (>20% del total de larvas de decápodos) en más de la mitad de las estaciones. Se encontró que las comunidades larvarias de decápodos son más ricas y diversas en la cabecera del cañón, lo cual podría explicarse por los altos índices de retención que presenta esta zona en comparación con las paredes del cañón y su eje., This research was carried out within project OAMMS (CTM2008-03983), financed by the Spanish Ministerio de Economía y Competitividad. Molecular analyses were done by AllGenetics (A Coruña, Spain)., With the funding support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S), of the Spanish Research Agency (AEI)

Crustacean Genomics: Implications for Physiology and Systematic Studies.-- 22 pages, 7 figures, 4 tables, supplementary material https://doi.org/10.1007/s10750-018-3521-3, The Norway lobster Nephrops norvegicus is the most important commercial crustacean species in Europe. Recent decline in wild captures and a reduction in total abundance and size at first maturation indicate that the species is overexploited. Increasing knowledge of its reproduction, specifically at the molecular level will be mandatory to improving fisheries management. The current study investigated differences between immature and mature N. norvegicus females using Next Generation Sequencing technology applied to multiple tissues. Ovarian maturation-related differential expression patterns were observed for 4362 transcripts in ovary, hepatopancreas, eyestalk, brain, and thoracic ganglia in N. norvegicus. Transcripts detected in the study include vitellogenin, crustacean hyperglycaemic hormone, retinoid X receptor, heat shock protein 90 and proteins encoding lipid and carbohydrate metabolizing enzymes. From the study, data were collected that can prove valuable in developing more comprehensive knowledge of the reproductive system in this lobster species during the ovarian maturation process. Additional studies will be required, however, to identify potential novel genes and to develop a molecular toolkit for crustacean species that can be applied to improving sustainable future production, The current study was supported by a Marie Curie International Research Staff Exchange Scheme Fellowship within the 7th European Community Framework Programme (612296-DeNuGReC) and a USC International PhD scholarship to Tuan Viet Nguyen

9 pages, 7 figures, 1 table, Commercial bottom trawling causes some of the largest impacts on the sea floor, and it has been identified as one of the major drivers of sediment resuspension on continental slope regions, particularly in areas surrounding submarine canyons. To assess whether there have been significant trawling-induced alterations in the sediment dynamics within the Foix Canyon (Northwestern Mediterranean) during the past century, sediment accumulation rates obtained using Pb and Cs radiochronology were compared between sediment cores retrieved in 1993 and in 2013 from the canyon axis at 860 m depth. The results indicate an almost two-fold increase in the sedimentation rate in the 1960–70s, from 0.5 cm·y to 0.9 cm·y, as a consequence of the rapid industrialization of the fishing sector at that time. Sedimentation rates further doubled to 1.8 cm·y in the early 2000s. This period was characterized by the construction of bigger trawlers with more powerful engines as well as the modernization of the engines of existing vessels, all of which were largely under-declared. These results provide compelling evidence of the increasing impact of bottom trawling due to the modernization of trawling fleets at the beginning of the XXI century, This research has been supported by PERSEUS (GA 287600) European grants, by FORMED (CGL2012-33989) and ABIDES (CTM2015-65142-R) Spanish grants, by the Generalitat de Catalunya supporting grants 2014 SGR-1642 and 2014 SGR-1356, as well as a predoctoral F.P.U. grant from the Spanish government

13 pages, 9 figures, 4 tables, 1 appendix, Crustacean suprabenthic abundance, community structure, α-diversity (both taxonomic and trophic) and β-diversity were studied along a West-East gradient of oligotrophy in the deep Mediterranean Sea. The assemblages were sampled with a suprabenthic sledge in three regions (western, central and eastern basins) at three water depths (1200, 2000 and 3000 m) in May-June 2009. Environmental data were obtained at each sampling location including sediment properties, oceanographic variables near the seafloor and in the water column, and proxies of epipelagic productivity at the surface. Our results, concerning the crustacean component of the suprabenthos, showed complex trends in community structure and biodiversity across different spatial scales (longitudinal, bathymetric, and near-bottom distribution). A decrease in the number of species and abundance, accompanied by changes in the trophic structure of the assemblages were observed from West to East. In the eastern region the assemblages were impoverished in number of trophic guilds and trophic diversity. The West-East oligotrophic gradient was identified as the main driver in community structure as shown by the significant correlation with trophic environmental variables. Differences in community structure across regions were more marked at greater depths, while at the shallower sites assemblages were more similar. Within each basin, abundance, number of species and number of trophic groups decreased with depth, showing high turnover rates between 1200 and 2000 m depths. The small-scale (0–150 cm) vertical distribution of the suprabenthos was interpreted in relation to the species’ functional traits (e.g. swimming activity, migratory behaviour, bottom dependence, feeding habits). Bottom-dependent and more mobile components of the suprabenthos were apparently responding differently to the various environmental challenges imposed by the large-scale longitudinal and bathymetric gradients. We propose that the bathyal suprabenthos in the Mediterranean Sea may be essentially modulated by environmental sorting, but while the more mobile faunal component has more efficient dispersal mechanisms, the bottom-dependent component may be affected by limited dispersal. However, this empirical interpretation has still to be proved given the important caveats of our study (e.g. typically low densities of the Mediterranean bathyal suprabenthos; limited number of samples; difficulties in standardization inherent to suprabenthic sampling operations in the deep sea), This work was funded through the BIOFUN project (CTM2007-28739-E) within the framework of the EuroCores EuroDEEP programme (European Science Foundation). This study was partially funded by Fundação para a Ciência e Tecnologia (FCT) under the projects PEst-C/MAR/LA0017/2013 and UID/AMB/50017/2013. The first author was funded by a PhD grant from FCT (SFRH/BD/69450/2010).

8 pages, 6 figures, 2 tables, This study describes the distribution and composition of litter from the Gulf of Cadiz (Northeastern Atlantic,Spain), a region of confluence between the Atlantic and Mediterranean, with intense maritime traffic. Several geological features, such as canyons, open slopes and contourite furrows and channels, were surveyed by remotely operated vehicle (ROV) observations between depths of 220 and 1000 m. Marine litter was quantified by grouping the observations into six categories. Our results indicate the presence of markedly different habitats in which a complex collection of different types of litter accumulate in relation to bottom current flows and maritime and fishing routes. This result justifies a seascape approach in further anthropogenic impact studies within deep-sea areas, The present study was developed in the framework of the Tecnoterra (ICM-CSIC/UPC) Associate Unit and the following project activities, funded by the Spanish Government MOWER (CTM2012-39599-C03), FAUCES (CTM2015-65461-C2-1-R) and RESBIO (TEC2017-87861-R), plus the ARIM (Autonomous Robotic sea-floor Infrastructure for benthopelagic Monitoring) funded by the MartTERA ERA-Net Cofound. Francescangeli M. was funded by the European Project ERASMUS grant 2017. Mecho A. was partially funded by the Pure Ocean Fund, managed by the King Baudouin Foundation, With the funding support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S), of the Spanish Research Agency (AEI)

Special issue Bridging the gap between the shallow and deep oceans: The key role of submarine canyons.-- 13 pages, 8 figures, 4 tables, supplementary material https://doi.org/10.1016/j.pocean.2018.02.022, Submarine canyons and adjacent slopes from the NW Mediterranean Sea are subjected to high seasonal and inter-annual variability in hydrodynamic processes. Such an environmental setting has a profound influence in the spatial and temporal variability of deep-sea benthic assemblages. We analyzed the suprabenthic crustacean assemblages from the Blanes Canyon and the adjacent slope along a bathymetric gradient. Macer-Giroq sledge hauls were taken from 900 to 2250 m depth in the canyon axis and southwestern adjacent slope in the autumn of 2008, 2009 and 2012. From the twenty four hauls sampled, one hundred and seventy one species were identified. Major changes in densities, number of species and diversity were only found at particular depths or years. In general the samples yielded variable densities (from approx. 10 to 539 ind.100 m), mostly owing to temporal fluctuations in motile fauna such as amphipods and mysids, in relation to the occurrence of energy-driven events. The environmental conditions associated to these events coupled with particular topographic features at the shallowest sites (namely at 900 m depth) lead to contrasting biodiversity patterns in the canyon and adjacent slope: high dominance and subsequent depressed diversity in the canyon and the highest diversity on the slope at similar depths. At the deepest sites, suprabenthic diversity reached similar values in the canyon and adjacent slope, probably owing to the decreased influence of disturbance processes at greater depths. Trophic diversity decreased with depth only in the slope, while in the canyon it remained constant likely owing to the relatively enhanced trophic conditions found in the canyon at all depths. However, the community composition differed significantly between the canyon and adjacent slope and at contrasting depths (1200 m). At shallowest depths, the canyon sites were characterized by a high contribution of motile omnivores while the slope sites were characterized by a high contribution of detritivores to the total abundance. Highly motile predators on zooplankton were dominant at deepest sites in both environments. Our results suggest that taxonomic and trophic diversity in the northwestern Mediterranean may be influenced by the abrupt topography and its interaction with hydrodynamic conditions (intensification of currents; variable intensity of disturbance/hydrodynamic events; food pulses linked to food availability). These are major drivers which influence the spatial and temporal availability of food sources to the various faunal compartments eventually propagating up the food web, The present work was funded by the MICYT Project PROMETEO (CTM2007-66316-C02/MAR), the European Science Foundation Project BIOFUN (CTM2007-28739-E) and Project DOS MARES (CTM2010-21810-C03-03). This work was supported by CESAM (UID/AMB/50017) funds, granted by FCT/MEC through national funds, and the co-funded by FEDER, within the PT2020 Partnership Agreement and Compete 2020. The first author was funded by a PhD grant from FCT (SFRH/BD/69450/2010).

11 pages, 10 figures, 4 tables, The deep-sea red shrimp Aristeus antennatus is one of the most valuable demersal resources for bottom trawl fishery in the Mediterranean Sea. Nevertheless, this fishery lacks specific management at Mediterranean level, data availability is sparse and official records are often unreliable. In particular, misreporting of trawlers engine power is a widespread issue, complicating the process of fish stock assessments. In Catalonia (Northeast Spain), the red shrimp is particularly important and the stock has been traditionally exploited. The aim of this study was to investigate the long-term effects of intense fishing activities on this resource. For this purpose, we built a reliable series of fishing effort and catch per unit of effort (CPUE), integrating official data with information obtained by interviews to fishermen. Stock assessment at two different time periods, 1984-1989 and 2008-2010, was performed. In this study, we provide the first evidence of the remarkable increase of fishing effort in the Northwest Mediterranean Sea in the last decades. Overfishing of the red shrimp was detected at all years studied. A decrease in the yield per recruit and mean individual length over the two time periods considered was also detected. In addition, the CPUE presented a marked decreasing trend, indicating a possible reduction in the resource abundance. Our results show that an appropriate fishery management for this resource is needed, and should aim at reducing fishing mortality and increasing yield per recruit. These objectives could be achieved by reducing fishing effort and increasing size at first capture, The EC Program Science in Society EC. FP7 (ref # 266544-GAP2), the Generalitat de Catalunya Monitoring Project no.070105070011, the FPU grant of the Spanish Ministry of Education and the Marine Stewardship are acknowledged for financial support

Este artículo contiene 6 páginas, 6 figuras, 4 tablas., [EN]The deep-sea red shrimp Aristeus antennatus is one of the most valuable demersal resources in Catalonia (northeast Spain), and Palamós is the most important harbour for this fishery in the area. Here, a management plan published in 2013 established the use of a 40-mm square-mesh codend (40s), replacing the previously used 50-mm diamond mesh codend (50d). The objective was to decrease the amount of juveniles in the catches, but the regulation did not bring the expected results. In this study, we measured and compared the selectivity of the 40s and the 50d in this fishery. In addition, we experimented with the use of a 50-mm square-mesh codend (50s). According to our results, the 40s had a lower 50% selection length (L50) than the 50d, while the 50s had a substantially higher L50 than the other two. A transition analysis showed an increase in yield per recruit after the second year from a hypothetical implementation of the 50s. Our conclusion is that the 40s does not have a higher selectivity than the 50d, which (at least partially) explains the failure to reach the management objective in Palamós. Conversely, the use of a 50s would significantly benefit the fishery, increasing gear selectivity and yield per recruit.[ES]La gamba roja, Aristeus antennatus, es uno de los recursos demersales más valorados en Cataluña (noreste de España). Palamós es el puerto pesquero más importante para esta pesquería en la región. Una orden ministerial regulatoria y específica para este puerto, publicada en 2013, estableció la utilización de un copo de malla cuadrada con abertura mínima de 40 mm (40s), reemplazando el copo de malla romboidal de 50 mm (50d) utilizado hasta la fecha. El objetivo era disminuir la cantidad de juveniles en la captura, pero la regulación no consiguió los resultados esperados. En el presente estudio, se midió y comparó la selectividad del copo de 50d y 40s en esta pesquería. Además, se experimentó el uso de una malla cuadrada de 50 mm (50s). Los resultados mostraron que el copo de 40s presentaba una talla de retención del 50% (L50) menor comparado con el copo de 50d, mientras que el de 50s tenía una L50 considerablemente mayor que los demás copos. El análisis de transición mostró un aumento del rendimiento por recluta (Y/R) después del segundo año desde la hipotética implementación del copo de 50s. Nuestra conclusión es que el copo de 40s no tiene una selectividad mayor que el copo de 50d, explicando (por lo menos en parte) la falta de consecución de los objetivos de gestión en la pesquería de gamba de Palamós. En cambio, el copo de 50s mejoraría significativamente a la pesquería, aumentando la selectividad del arte y el Y/R., We are grateful for the financial support of the EC Programme Science in Society EC FP7 (ref. 266544-GAP2), the CONECTA research project (ref. CTM2014-54648-C2-1-R) funded by the Spanish Government, the FPU grant of the Spanish Ministry of Education and the Marine Stewardship Council.

Este artículo contiene 12 páginas , 7 figuras, 3 tablas, This study reports the composition and distribution of demersal megafauna from various north-western Mediterranean submarine areas such as canyons, seamounts and landslides between 60–800 m depth, based on remotely operated vehicle (ROV) observations. From a total of 30 h of video, 4534 faunistic observations were made and analysed in relationship to environmental factors (i.e. topography, substrate type and depth). In addition, anthropogenic impact was quantified by grouping observations in four categories: fishing nets, longlines, trawl marks and other litter. The different targeted environments showed similarities in faunal composition according to substrate, depth and topography. Our results also indicated the presence of anthropogenic impact in all the sampled areas in which litter and trawl marks were the most observed artefacts.

11 pages, 5 figures, 2 tables, The Norway lobster, Nephrops norvegicus is a target fishery species in European waters. The stock assessment of N. norvegicus is complicated because it is caught in commercial gear only when it emerges from its burrow. Landings are lower in winter, and feeding limitations have been hypothesized as the cause. Wild large-sized male lobsters were sampled each season (winter, spring, summer and autumn), and two groups of animals were kept in captivity for 90 d (fed and food-deprived). The hepatopancreas and muscle were dissected, weighted, frozen for biochemical analyses (proximal analyses and DNA/RNA) and fixed in Bouin solution for microscopic observations. The oxygen consumption rates in the wild individuals caught in the spring and in the captive animals after the treatments were measured. Significant differences among the experimental groups were observed in the lipid concentration of the hepatopancreas and muscle, the water content in the hepatopancreas, and the numbers of vacuoles and pyknotic nuclei in the cells of the tubules of the hepatopancreas. The results showed that the wild Norway lobsters generally presented intermediate values between those observed in the food-deprived and the fed lobsters kept in captivity, but the values were closer to those obtained for the fed animals. This finding indicates that the wild animals exhibit a good nutritional condition throughout the year. Therefore, the wild males of N. norvegicus do not face food deprivation during winter as is suggested by the pattern of commercial catches, the flow of organic matter, and the moulting period/reproductive behaviour of the species. Copyright © Marine Biological Association of the United Kingdom 2014, This paper is a product of the Spanish CICYT Project BIFICRUST (REN2001-0729), which involves L. Fernández and F. Sardà, and was supported by a grant from the Xarxa de Referència de Recerca en Aqüicultura of the Generalitat de Catalunya to G. Rotllant. Jacopo Aguzzi is a Postdoctoral Fellow of the ‘Ramon y Cajal’ Program (MICINN)

Special Issue Integrated study of a deep submarine canyon and adjacent open slopes in the Western Mediterranean Sea: an essential habitat.-- 11 pages, 7 figures, 2 tables, Throughout the deep oceans, diversity in the benthos peaks at intermediate slope depths. In the western Mediterranean lower slope an accumulation of biomass, but not diversity, at depths of 1200-1350. m has been observed. However, the precise causes of this biomass peak are unknown. We examined the patterns of megafauna benthic biomass in the Catalan sea open slope, from 900 to 1750. m depth, expanding the results in the context of the whole continental margin. Sampling was carried out by combining an Otter-Trawl Maireta System (OTMS) and an Agassiz trawl, during four different seasons in 2008/2009. At the same time, current speed, temperature and salinity were obtained year-round by means of near-bottom deployed sensors (current meters and temperature-conductivity sensors). Total biomass followed an inverted U-shaped pattern, peaking at depths of 1050-1350. m. Range-related ecological forcings between shallower and deeper species may have caused this biomass accumulation at intermediate slope depths. We also report on the seasonal variations of biomass in the studied depth range, identifying a dynamic zone above 1000. m depth where populations of highly mobile species perform year-round migrations throughout the slope, and a more static region below 1000. m (i.e. the twilight zone end) with substantially less inter-annual variations. The arrival of new Western Mediterranean Deep Water from the deep basin to the lower slope in March-May may have driven the accumulation of biomass at 900 and 1050. m depth over the same period. In addition, an adjacent submarine canyon was sampled with the same procedures to characterize its benthic megafauna community. Analyses revealed higher diversity, but not biomass, inside the canyon than in the adjacent open slope, and a significantly different assemblage composition between the two habitats. These results strengthen the concept of submarine canyons as hotspots of biodiversity and underline the importance of their conservation as diversity repositories. © 2013 Elsevier Ltd., The present work was funded by the MICYT Project PROMETEO (CTM2007-66316-C02/MAR), the European Science Foundation Project BIOFUN (CTM2007-28739-E) and the European Community HERMIONE Project (FP7/2007–2013, Grant agreement no. 226354). Physical analyses were also supported by the GRACCIE-CONSOLIDER (CSD2007-00067) research project, and a Generalitat de Catalunya ‘Grups de Recerca Consolidats’ grant (2009 SGR 1305). S.T. was funded by a JAE-PRE-2008 grant and ERLL by a JAE-DOC grant, both from the CSIC and co-financed by the European Union. J.A. and A.S. are postdoctoral fellows of the Ramón y Cajal program (MICINN)

Special issue Integrated study of a deep submarine canyon and adjacent open slopes in the Western Mediterranean Sea: an essential habitat.-- 15 pages, 10 figures, 2 tables, The distribution, type and quantity of marine litter accumulated on the bathyal and abyssal Mediterranean seafloor has been studied in the framework of the Spanish national projects PROMETEO and DOS MARES and the ESF-EuroDEEP project BIOFUN. Litter was collected with an otter trawl and Agassiz trawl while sampling for megafauna on the Blanes canyon and adjacent slope (Catalan margin, north-western Mediterranean) between 900 and 2700 m depth, and on the western, central and eastern Mediterranean basins at 1200, 2000 and 3000 m depth. All litter was sorted into 8 categories (hard plastic, soft plastic, glass, metal, clinker, fabric, longlines and fishing nets) and weighed. The distribution of litter was analysed in relation to depth, geographic area and natural (bathymetry, currents and rivers) and anthropogenic (population density and shipping routes) processes. The most abundant litter types were plastic, glass, metal and clinker. Lost or discarded fishing gear was also commonly found. On the Catalan margin, although the data indicated an accumulation of litter with increasing depth, mean weight was not significantly different between depths or between the open slope and the canyon. We propose that litter accumulated in the canyon, with high proportions of plastics, has predominantly a coastal origin, while litter collected on the open slope, dominated by heavy litter, is mostly ship-originated, especially at sites under major shipping routes. Along the trans-Mediterranean transect, although a higher amount of litter seemed to be found on the Western Mediterranean, differences of mean weight were not significant between the 3 geographic areas and the 3 depths. Here, the shallower sites, also closer to the coast, had a higher proportion of plastics than the deeper sites, which had a higher proportion of heavy litter and were often affected by shipping routes. The weight of litter was also compared to biomass of megafauna from the same samples. On the Blanes slope, the biomass of megafauna was significantly higher than the weight of litter between 900 and 2000 m depth and no significant differences were found at 2250 and 2700 m depth. Along the trans-Mediterranean transect, no significant differences were found between biomass and litter weight at all sites except in two sites: the Central Mediterranean at 1200 m depth, where biomass was higher than litter weight, and the Eastern Mediterranean at 1200 m depth, where litter weight was higher than biomass. The results are discussed in the framework of knowledge on marine litter accumulation, its potential impact on the habitat and fauna and the legislation addressing these issues, This study was funded by the PROMETEO project (CTM2007-66316-C02/MAR, CICYT), the BIOFUN project (CTM2007-28739-E, European Science Foundation and national funding agencies), the DOS MARES project (CTM2010-21810-C03-03) and the European Community’s Seventh Framework Programme under the HERMIONE project (Grant Agreement 226354). EZR is funded by a JAE-DOC CSIC postdoctoral grant with co-funding from the European Social Fund. MC was funded by EC Marie-Curie IOF Fellowship to ECOFUN and Spanish Fellowship Program Ramón y Cajal

Special issue Integrated study of a deep submarine canyon and adjacent open slopes in the Western Mediterranean Sea: an essential habitat.-- 11 pages, 4 figures, 3 tables, Due to their geomorphological structure and proximity to the coastline, submarine canyons may act as natural conduit routes for anthropogenic contaminants that are transported from surface waters to the deep-sea. Organisms dwelling in these canyon environments might thus be at risk of experiencing adverse health effects due to higher pollution exposure. To address this question, chemical and biochemical analyses were conducted on two of the most abundant deep-sea fish species in the study area, namely Alepocephalus rostratus and Lepidion lepidion, and the most abundant deep-sea commercial decapod crustacean Aristeus antennatus sampled inside Blanes canyon (BC) and on the adjacent open slope (OS). Persistent organic pollutants (POPs) levels, including polychlorinated biphenyl (PCB), dichlorodiphenyltrichloroethane (DDT) and derivatives, hexachlorocyclohexanes (HCHs) and hexachlorobenzene (HCB) were determined in muscle tissue of selected samples from 900. m and 1500. m depth. Potential effects resulting from contaminant exposure were determined using hepatic biomarkers such as ethoxyresorufin. -O-deethylase (EROD), pentoxyresorufin. -O-deethylase (PROD), catalase (CAT), carboxylesterase (CbE), glutathione-. S-transferase (GST), total glutathione peroxidase (GPX), glutathione reductase (GR) and superoxide-dismutase (SOD) enzyme activities and lipid peroxidation levels (LP). L. lepidion and A. antennatus tissues exhibited higher POP levels inside BC compared to the OS at 900. m depth. These findings were consistent with biomarker data (i.e. enzymatic response to presence of contaminant agents). Elevated xenobiotic-metabolizing (EROD and PROD) and antioxidant enzymes (CAT and GPX) indicated higher contaminant exposure in both species caught within BC. No difference in POP accumulation between sites was observed in L. lepidion at 1500. m depth, nor in biomarker data, suggesting that the pollution gradient was less pronounced at greater depths. This trend was further corroborated by the results obtained for A. rostratus at 1500. m depth. Hence, the present findings suggest the, at least temporary, existence of a pollution gradient between Blanes canyon and the open slope at shallower depths and this resulted in alterations of the physiology of deep-sea organisms dwelling within this area. © 2013 Elsevier Ltd., The present work was funded by the Spanish Science and Technology Ministry Projects PROMETEO (CTM2007-66316-C02-02/MAR to JBC), DOS MARES (CTM2010-21810-C03-03/MAR to JBC), BIOFUN (CTM2007-28739-E/MAR to Francesc Sardà) and HERMIONE Project (EC-FP7 Contract Number 226354). Samuel Koenig holds a PhD Grant (AFR 08/067) from the Fonds National de la Recherche (FNR), Luxembourg

7 pages, 4 figures, Recruitment of Aristeus antennatus over the species' entire depth range and distribution area in the Mediterranean Sea is described. Because of the dearth of information on the recruitment of deep-sea species in the literature, the findings reported here take on special significance. Samples were collected at depths between 900 and 2800 m on seven trawl surveys using three samplers: an OTMS trawl, an Agassiz bottom frame trawl, and a Macer-Giroq suprabenthic sledge, computing a total of 80, 26 and 14 trawls, respectively. Early juveniles (≤ 15 mm CL) were observed to be present down to a depth of 2800 m and to attain maximum percentage abundance between 1350 and 2000 m. Spring was the season of peak abundance for juveniles. Several hypotheses explaining this deep-sea recruitment are discussed, including oceanographic events coupled with enrichment of the bathyal bottoms and competitive exclusion in deep-sea species. Studying the deep-sea recruitment of A. antennatus contributes to our understanding of the species' life history and supplies knowledge essential to proper management and sustainable exploitation of the species, The authors are grateful to the crews of the R/V García del Cid and the R/V Sarmiento de Gamboa (CSIC). The PROMETEO and BIOFUN (ESF) programmes were funded by MINISTERIO DE CIENCIA E INNOVACIÓN (MICINN). Thanks to Samuele Tecchio and Joan Navarro for graphic assistance

17 páginas, 8 figuras, 5 tablas, 1 apéndice con 3 tablas., Blanes Canyon and its adjacent margin are important fishery areas (mainly by bottom trawling) located in a highly energetic oceanographic setting in the NW Mediterranean Sea. Here we assess the spatial and temporal variability in abundance, diversity and community structure of the suprabenthic peracarid assemblages in this region and examine this variability in relation to the natural and anthropogenic (trawling fisheries) disturbance regimes. The sampling was conducted between March 2003 and May 2004 in three main fishing grounds, the canyon head (average depth: 490 m), the canyon wall (average depth: 550 m) and the eastern adjacent slope (average depth: 820 m), as well as in two non-exploited areas in the western (at 900 m depth) and eastern (at 1500 m depth) slope near the canyon mouth. A total of 138 species were identified, with amphipods being the most speciose and abundant group, followed by mysids in terms of abundance. Our results show high spatial and temporal variability in suprabenthic assemblages. Densities were higher in the canyon head and western slope, which appear to be the preferential routes for water masses and particle fluxes in months of flood events, and other energetic processes. In the canyon head, where periodic erosion processes are more active, low diversity, high dominance and higher turnover (β-diversity) were observed, apparently coupled with significant temporal fluctuations in the densities of the highly motile component of suprabenthos (mysids, predatory and scavenging amphipods). In the sedimentary more stable eastern slope, high diversity values were observed, accompanied by a higher relative contribution of the less motile groups (i.e. amphipods, most isopods, cumaceans). These groups have a closer interaction with the sediment where they exploit different food sources and are more susceptible to physical disturbance. Temporal variability in their diversity may be related to changes in food quality rather than quantity. In the canyon wall, temporal fluctuations in diversity indices were only revealed in relation to the overall higher and more continued fishing pressure observed in the canyon wall fishing ground (Cara Norte/Sot site). Here, species richness and abundance declined with increasing fishing pressure but the lowest trophic and taxonomic diversities were observed under intermediate levels of disturbance. These findings underline (i) the differences between relatively low and highly motile taxa in terms of response to disturbance events; (ii) the differences between assemblages subjected to different levels of natural disturbance and trawling pressure, which modify the common bathymetric patterns of abundance and diversity often described from continental margins., This study was conducted within the framework of the project RECSII (REN02/04556/C02/ MAR) by the Spanish Science and Innovation Agency. The study is a contribution of D. Martin to the Consolidated Research Group 2014SGR120 of the Generalitat de Catalunya. The first author was supported by Fundação para a Ciência e Tecnologia: SFRH/BPD/ 21459/2005. C. Romano received funding from the People Programme (Marie Curie Action) of the European Union's Seventh Framework Programme (FP7/2007-2013) under REA grant agreement N. PIOF-GA-2013-628146. This study was partially funded by Fundação para a Ciência e Tecnologia (FCT) under the projects PEst-C/MAR/LA0017/2013 and UID/AMB/50017/2013.

12 páginas, 6 figuras, 5 tablas., There is a general hypothesis that species inhabiting deep-sea waters have lower fecundity and larger eggs than shallower species. However, there are few comparative studies which explore this trend because of the complexity of sampling in deep waters, especially in fishes. We present here the first analysis of fecundity and egg size with depth along an isothermal environment. We calculate the relative fecundity and egg size of 11 species of demersal deep-sea fish from the western Mediterranean and included in our analyses published data for an additional 14 species from the same geographic area. The results show that the relative fecundity (eggs per g of individual) of the analyzed fishes slightly decreased along the bathymetric gradient, whereas egg size increased with depth. When the analysis was conducted including only species from the order Gadiformes, the most speciose group in the region and with the widest depth range of distribution (50–2000 m), there was no relationship between relative fecundity and depth, while the deepest species had larger egg sizes than shallower ones. The finding of similar relative fecundities but larger egg sizes suggests that these deep-sea species are investing a higher amount of energy in the production of offspring than shallower water counterparts. The results are discussed in relation to the isothermal characteristics of the deep Mediterranean Sea and ecological adaptations for reproductive success., This study was conducted within the framework oft he RECS(REN02/04556/C02/MAR), PROMETEO(CTM2007-66316-C02/MAR) and DOSMARES (CTM2010-21810-C03-03/MAR) projects by the Spanish Science and Innovation Ministry respectively, to JBC.

5 pages, 4 figures, Bottom trawling is a non-selective commercial fishing technique whereby heavy nets and gear are pulled along the sea floor. The direct impact of this technique on fish populations1, 2 and benthic communities3, 4 has received much attention, but trawling can also modify the physical properties of seafloor sediments, water–sediment chemical exchanges and sediment fluxes5, 6. Most of the studies addressing the physical disturbances of trawl gear on the seabed have been undertaken in coastal and shelf environments7, 8, however, where the capacity of trawling to modify the seafloor morphology coexists with high-energy natural processes driving sediment erosion, transport and deposition9. Here we show that on upper continental slopes, the reworking of the deep sea floor by trawling gradually modifies the shape of the submarine landscape over large spatial scales. We found that trawling-induced sediment displacement and removal from fishing grounds causes the morphology of the deep sea floor to become smoother over time, reducing its original complexity as shown by high-resolution seafloor relief maps. Our results suggest that in recent decades, following the industrialization of fishing fleets, bottom trawling has become an important driver of deep seascape evolution. Given the global dimension of this type of fishery, we anticipate that the morphology of the upper continental slope in many parts of the world’s oceans could be altered by intensive bottom trawling, producing comparable effects on the deep sea floor to those generated by agricultural ploughing on land, This work was supported by various research projects: HERMIONE (226354 and CTM2010-11084-E), DOS MARES (CTM2010-21810-C03),OASIS DEL MAR—Obra Social ‘‘la Caixa’’, GRACCIE-CONSOLIDER (CSD2007-00067) and REDECO (CTM2008-04973-E). We also received support from Catalan Government Grups de Recerca Consolidats grants (2009 SGR 899 and 1305). VMS data and support were provided by the Spanish General Secretariat of Maritime Fishing (SEGEMAR). Assistance at sea by the crews of RV Hespérides, RV Sarmiento de Gamboa and RV García del Cid is also acknowledged. J.M. was funded through a JAE-DOC contract granted by Consejo Superior de Investigaciones Científicas and co-financed by the European Social Fund. F. Sarda and T. Milligan provided comments on the manuscript. The final document benefited from a review by P. Talling

12 pages, 10 figures, 6 tables, Macrourid fish are one of the most abundant marine species on continental margins worldwide. Although they play an important role in the ecosystem, little is known about their overall biology. We report here a large data set of the most abundant macrourid in Mediterranean waters, Trachyrincus scabrus, showing the main population and reproductive characteristics. The study was based on 3,239 specimens collected between 300 and 1,500 m depth on the northwestern Mediterranean in 2003–2004 and 2008–2009. The population showed a depth-related structure with the largest individuals at 1,100 m depth and the smallest (i.e., immature) at shallower depths. Macroscopic and microscopic analyses of the gonads showed that T. scabrus has a highly seasonal reproductive pattern. Spawning females were found during winter when the organic matter fluxes were highest on the continental slope. T. scabrus is a batch spawner with group-synchronous oocyte development and present low average fecundity of 14,191 oocytes, The authors would like to thank the Officers and crews of the R/V Garcia del Cid, F/V Montse III and Virgen del Vilar for helping to provide samples and the data necessary for our study. We also thank I Quagio-Grassiotto, M Metaksakis and C Cerviño for helping with the histological analyses and JA Garcia for developing the study area map. This study was conducted within the RECS, PROMETEO and DOS MARES projects by the Spanish Science and Innovation Ministry CICYT (REN02/04556/C02/MAR; CTM2007-66316-C02/MAR; CTM2010-21810-C03-03/MAR, respectively, to JBC) and European Community’s Seventh Framework Programme under the HERMIONE project (Grant Agreement 226354, to ERLL). UF-A is funded by a Spanish PhD doctoral fellowship FPI-2008. ERLL is funded by a Spanish JAE-CSIC postdoctoral grant. This paper is a contribution number 580 from AZTI Tecnalia (Marine Research Division)