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22 pages, 9 figures, 4 tables, 3 appendices, We evaluated seasonal patterns of biodiversity of the megabenthic non-crustacean invertebrates on soft bottoms of the continental shelf and slope of the Catalan Sea (Balearic Sea, Northwestern Mediterranean). Scientific demersal trawls were carried out between 30 and 400 m during winter and summer of 2013 in 37 and 45 stations respectively. Among a total of 188 species, a limited number of echinoderms, cephalopods and occasionally ascidians dominated the bulk of the community, covering up to 95% of the total wet weight. Seasonal and bathymetric variations were found in the different biodiversity patterns, with higher values in summer and in shallower depths, regarding overall wet weight (>14,000 kg/km2), density (>1 million ind/km2), richness and diversity (143 species; H’=1.74). The statistical differences in density and wet weight between bathymetric strata reflected in particular groups of species typifying each environment, but without any exclusiveness in depth preferences, since generalist species were the main components of the community. Depth was the main driver of statistical differences in the community structure, but a combined influence of geographic location was also identified from an interaction effect. Sediment type may be influencing habitat preferences, with echinoderms (especially crinoids Leptometra and Antedon), dominating on sandy substrates, and cephalopod mollusks (especially cephalopods Illex, Eledone, Octopus) dominating on muddy substrates. Trawling activity may also influence the dominance of some target and non-target species. Several infrequent bivalves, opistobranchs and species from phyla Porifera, Cnidaria, Bryozoa and Sipuncula constituted an important understudied component of the richness of this community. This is the first study dealing with bathymetric variation of the megabenthic non-crustacean community of the Catalan Sea within this gradient of depths above the middle slope and also considering seasonal variability, Financial support to conduct this research was provided by the Spanish National Project ECOTRANS, whose members participated in the in study design and the collection, analysis and interpretation of data

9 pages, 5 figures, 5 tables, In marine communities, energy of small planktonic organisms is transferred to their predators through feeding. The energy accumulated as organic substances by the different plankton organisms (Energetic Density content, E) has been analysed in high latitudes and tropical areas, but not in the Mediterranean Sea. In this study, we approach this type of investigation for Mediterranean plankton through measures of total calorimetric content using an oxygen bomb calorimeter. We examined the spatiotemporal variation in the E of microplankton (50–200 μm) and mesozooplankton (200–2000 μm), and two plankton-consumers, sardine (Sardina pilchardus) and anchovy (Engraulis encrasicolus) larvae. The study was carried out during the winter and summer of 2013 off the Ebro River Delta (NW Mediterranean Sea). Both plankton fractions showed a more coastal distribution and higher biomasses during winter, the period of sardine larvae occurrences, in front of a wider cross-shelf distribution and lower biomasses in summer, when anchovy appeared. E values increased with the size of each plankton component, i.e., microzooplankton < mesozooplankton < fish larvae. A tendency for higher plankton E in the winter period was observed, although being only significant for coastal zone, associated to the more productive waters there. Sardine and anchovy larvae showed an increasing trend in the amount of energy during development, with significantly lower E between early larvae (6–10 mm standard length) and late postflexion stages (16–20 mm standard length). Small larvae of both species departed from a similarly low E content, but in the next two size classes sardine larvae showed higher E values than anchovy, being significantly higher in the 16–20 mm size class. Information on larval feeding patterns and larval growth rates for each species were used to discuss differences in energy allocation strategies, This study forms a contribution to the project ECOTRANS (CTM201126333, Spanish Ministry of Economy and Competiveness, Spain) and to the Master's thesis of Z.B.

9 pages, 4 figures, 4 tables, Anchovy and sardine in the Mediterranean are known to share the same habitat and, consequently, to interact with one another. These two sympatric pelagic species are planktivorous and consume a wide range of planktonic prey items during all their developmental stages, potentially overlapping their ecological niches, although the feeding interactions between these species have been poorly investigated. Here we compare the dietary habits of the juvenile phases of anchovy and sardine during different seasons in the northwestern Mediterranean Sea, through analysis of their stomach contents and of their feeding-related anatomical characteristics. In this study we show that juveniles of anchovy and sardine do not compete for food, and we describe significant dietary differences between anchovy and sardine due to their different alimentary tract morphology. © 2014 Elsevier B.V., This researchwas conductedwithin the European project SARDONE (FP6 – 44294)

13 pages, 11 figures, 3 tables, 1 appendix supplementary material https://doi.org/10.1016/j.biocon.2012.06.029, The Mediterranean endemic starry ray (Raja asterias) is one of the few demersal skates that are still present in Mediterranean exploited ecosystems. However, this species has declined with time, its presence in survey data is scarce, and limited information is available about its ecology and the impact of fishing on its populations. We examined key ecological features of this species such as reproduction, trophic behaviour and growth. We assessed the ecological role of this species within the food web using an ecological model of a North-Western Mediterranean ecosystem and setting the new information in an ecosystem context. We then explored impacts of fishing on the starry ray population using a dynamic temporal model and we developed fishing scenarios aiming at recovering the species. Field and modelling results showed that the starry ray is a potentially ecologically important predator of the Mediterranean demersal ecosystems, but its ecological importance in the food web is moderate-low since it is present at a low abundance. Results confirmed that the species has been and still is highly impacted by fishing and it is very sensitive to increasing fishing impacts. However, alternative fishing scenarios showed that Mediterranean starry ray populations may respond under decreasing trawl fishing effort and could substantially recover. The recovery of the starry ray may be accompanied by recovery of other demersal species and could have wider ecosystem impacts. Therefore, this skate could be a good sentinel species to indicate ecosystem health in current Mediterranean Sea ecosystems. These new insights may be useful to ensure the recovery and conservation of this species while triggering the recovery of exploited marine communities in the Mediterranean Sea, M.C. was funded by the European Commission through the Marie Curie International Outgoing Fellowships to the ECOFUN Project (FP7-PEOPLE-2007-4-1-IOF) and the Spanish National Program Ramon y Cajal. J.N. was supported by a postdoctoral contract of the Juan de la Cierva program (MICINN-JDC, Spanish Ministry of Science and Innovation)

15 pages, 8 figures, 5 tables, Recruitment of European anchovy has been traditionally thought to largely depend on the passive transport and dispersion of eggs and larvae from spawning to nursery areas. Knowledge of the factors influencing the vertical distribution of fish early stages, and consequently influencing the transport, is a crucial issue in fisheries science. The aim of this study is to assess the relevance of diel vertical migration (DVM) as a mechanism involved in the transport of European anchovy larvae toward nursery areas taking into account age/stage-dependent vertical migration (i.e., the maximum migration). We developed a simplified vertical migration sub-model for anchovy larvae included in an Individual-based (IBM) hydrodynamic coupled model. Two types of simulation experiments were conducted: (1) ‘Pure’ Lagrangian (passive) transport experiments and (2) biological behavior transport experiments with a realistic scheme for egg-buoyancy, larval growth, and DVM scheme. We detected high variability in the trajectory and final position of larvae with 14 mm length between the passive and biological behavior experiments. The particles were less clustered in the passive transport experiment. In the biological experiment the particles were aggregated depending on the mesoscale oceanographic structures, evidencing a transport associated to filaments and meanders. The formation of schools was facilitated by the transport in filaments and larvae transported within filaments generally avoided the nucleus of the eddies and the central part of the North Current. Moreover, our results suggest that there is interconnectivity between all the anchovy sub-populations in the NW Mediterranean and that the Gulf of Lions and the shelf waters surrounding the Ebro River Delta are the most important areas for anchovy reproduction in this region. Additionally, we detected that the pre-recruitment is higher in those years when the larvae retention is favored. We underline that bottlenecks in larval transport modeling are related to the scarcity of knowledge in developmental biology and behavior of anchovy larvae and emergent mechanistic processes, This research was conducted within the European project SARDONE (FP6-44294). Egg samples were obtained from the MPOCAT-DEPM surveys financed by Generalitat de Catalunya. A. Ospina-Alvarez benefited from a PhD grant of the JAE program (CSIC)

Special issue Egg Production Methods in Marine Fisheries.-- 10 pages, 7 figures, 1 table, Small pelagic fish populations exhibit reproductive strategies resulting from past natural selection pressure, by which certain traits become more or less common in a population, allowing them to adapt and become better suited to certain habitats. One such adaptation is the buoyancy of eggs, which is observed as density changes during development. This is an important issue in fisheries and modeling science, as it affects the vertical distribution of eggs and, therefore, egg transport. Recently, individual-based models for anchovies in the Mediterranean have focused on developing adequate biological algorithms to simulate realistic spatial variations of eggs and larvae. Some models that include movements of particles according to Stokes’ law also assume a constant value of egg density during egg development. However, field observations show differences in the vertical distribution of eggs when egg density during development is considered. We address the problem of egg density and its vertical distribution within a biological context. In Mediterranean waters, the incubation time for anchovy eggs during peak spawning is approximately 48–70 h; during these first hours, egg density has an influence on the horizontal and vertical trajectories of eggs, as well as their routes and hatching zones. In this study, we introduce an algorithm describing the egg density of European anchovy eggs throughout development. Egg density measurements were carried out in a density gradient column (DGC). We fitted a polynomial model that estimated egg density, as a function of time from fertilization and that was dependent on temperature. Simulations to study the vertical transport of eggs in the Mediterranean were carried out using ICHTHYOP/MARS3D. The vertical distribution of pelagic eggs was determined by a set of interacting biological and physical parameters related to eggs (density, diameter) and ambient seawater (density, viscosity, turbulence), respectively. The egg buoyancy model introduced here was validated and will provide insight for the design of anchovy egg surveys, as the vertical position of the eggs in the water column during development can be inferred by the hydrographic structure of seawater, This research was conducted within the European project SARDONE (FP6 – 44294). Egg samples were obtained from the MPOCAT-DEPM surveys financed by Generalitat de Catalunya. A. Ospina-Alvarez benefited from a PhD grant of the JAE program (CSIC). We are indebted with AZTI-Tecnalia for providing us with the Density Gradient Column used to conduct our experiments. Thanks to Anne Elizabeth Mohan for proofreading the English. We are grateful to P. Garreau and A. Nicolle for their support with MARS-3D hydrodynamic model outputs, as well as to P. Verley for his assistance in ICHTHYOP code. Finally, the authors gratefully acknowledge the assistance of the captain and crew of the RV Garcia del Cid for their help during the cruise

8 pages, 4 figures, 1 table, Understanding how marine ecosystems are structured and how they function is a scientific challenge. Nowadays, to learn about ecosystem trophic dynamics ecologists use two complementary methodological approximations, mass-balance ecosystem models and isotopic tools. However, despite the wide applications of these methodologies, the comparison and combination of both are still scarce. The aim of this study was to examine the trophic dynamics of representative species of the South Catalan marine ecosystem (North-western Mediterranean) using the Ecopath ecosystem modelling tool and the stable isotope approach. By using the two methodologies we depicted the trophic position (trophic level and δ15N values) and trophic width (omnivory index and total isotopic area) of several species of fish, cephalopods, cetaceans, seabirds and one sea turtle. Our results show a clear correlation between the trophic levels estimated by the Ecopath model and the δ15N values, which validate the trophic position of several species in the study area and indicate that both methodologies are useful to determine the trophic position of marine species in Mediterranean marine food webs. In contrast, the two estimators of trophic width (the omnivore index and the total isotopic area) were not strongly related, since the relationship between modelling and stable isotope results was evident only for some species. Further comparisons of trophic width calculated in other marine food webs may provide a better understanding of our results and validate the accuracy of both methodological approaches to calculate trophic width, Research funds were provided by three projects from the Spanish Government (REN2000-0878/MAR, P06-RNM-02362, REN2002-00450). J. N. was supported by a postdoctoral contract of the Juan de la Cierva programme (MICINNJDC, Spanish Ministry of Science and Innovation). M. C. was funded by the European Commission through the Marie Curie International Outgoing Fellowships (ECOFUN project, FP7-PEOPLE-2007-4-1-IOF). M.L. was funded by a PhD fellowship of the Balearic Government, as well as by a postdoctoral contract of the Spanish Ministry of Education and Science (EX-2007-1148) and Marie Curie Individual Fellowship (PIEF-GA-2008-220063)

13 pages, 5 figures, 2 tables, This study presents a comparative analysis of protected and exploited Mediterranean Sea food webs using standardized ecological models of two ecosystems: the Central-North Adriatic Sea (highly exploited) and the Miramare Natural Marine Reserve (Northern Adriatic Sea, protected since 1986). Food webs are analysed in terms of structural and functional traits including trophic levels, transfer efficiency, trophic role of species and keystoneness, trophic spectra and other synthetic ecological indicators. Our results highlight similarities between food webs of the Adriatic Sea, differences that are likely due to the impact of fishing and differences that should be related to other factors. Analysis of biomass distribution along functional groups and of trophic spectra indicates that protected area presents higher mean trophic level of the community, higher biomasses, lower production and generally lower transfer efficiency than fished area. Our results indicate that measures of food web complexity (system omnivory index and ascendency), as well as pelagic/demersal and fish/invertebrates biomass ratios are higher in the protected area than in exploited ecosystem due to fishing-induced changes. Thus, this study highlights that marine protected areas can efficiently contribute to maintain structural and functional traits of marine ecosystems, This work was developed within the context of the SESAME project—EC Contract No. GOCE-036949, funded by the Sixth Framework Programme. M.C. was supported financially by postdoctoral fellowships from the Spanish Ministry of Science and Technology and by the European Community Marie-Curie Post-doctoral Fellowship through the International Outgoing Fellowships (IOF) (Call: FP7-PEOPLE-2007-4-1-IOF) to the ECOFUN project

20 pages, 9 figures.-- Issue title: "Ecological Functioning of the Iberian Seas: A synthesis of GLOBEC Research in Spain and Portugal"., In the NW Mediterranean Sea, anchovy (Engraulis encrasicolus) and sardine (Sardina pilchardus) are the most important small pelagic fish in terms of biomass and commercial interest. Round sardinella (Sardinella aurita) and Sprat (Sprattus sprattus) are also present in this region. This paper provides a general insight into the ecology of these species through a revision of the information available in an environmental context and in relation to exploitation features. Spawning habitats of the two main species, anchovy and sardine, are clearly differentiated based on water mass characteristics reducing the overlapping between their early developmental stages. Larval distribution is also related to major productivity mechanisms of the respective spawning seasons. In spite of the different environmental regimes in which larvae of these species develop, growth rates are fairly similar. Trophic modeling highlights the important ecological role of small pelagic fish in North Western Mediterranean ecosystems. This review points out the gaps in knowledge necessary to understand the dynamics of small pelagic fish in the region and to progress towards a precautionary and adaptive management

34 pages, 12 figures, 8 tables, 1 appendix, An exploited ecosystem from the continental shelf and upper slope of the Northwestern Mediterranean Sea was described by means of an Ecopath mass-balance model with the aim of characterising its functioning and structure and describing the ecosystem impacts of fishing. This application included some complexities added to the general modelling methodology due to the high biodiversity of the Mediterranean Sea and the multispecific nature of the fishery, and to the difficulties of working with fishing data which are usually irregularly or imprecisely collected. The model comprised 40 functional groups including primary producers, the main species of benthic, demersal and pelagic invertebrates, fishes and non-fish vertebrates and three detritus groups. In addition, trawling, purse seine, longline and troll bait fishing fleets were included., Results showed that the functional groups were organized into four trophic levels with the highest levels corresponding to anglerfish, dolphins, large pelagic fishes and adult hake. The system was dominated by the pelagic fraction, where sardine and anchovy prevailed in terms of fish biomasses and catches. Detritus and detritivorous groups also played key roles in the ecosystem and important coupled pelagic-demersal interactions were described. Considering Odum's theory of ecosystem development, the ecosystem was placed on an intermediate-low developmental stage due, at least partially, to the impact of fishing activity. This highlighted the high intensity of fishing in the ecosystem, in accordance with the general assessment of western Mediterranean marine resources, and fishing fleets were ranked as top predators of the system. The low trophic level of the catch was in line with the long history of exploitation in the area. However, the steady decline of pelagic landings between 1994 and 2003, coupled with a decrease of the pelagic biomass within the system, underlined the low resistance of the system in front of perturbations. This decline was reproduced under Ecosim dynamic simulations combining different scenarios of moderate increase of fishing effort and an environmental forcing affecting the availability of preys to small and medium-sized pelagic fishes under wasp-waist flow control, This research was funded by the Spanish research project CICYT.REN 2000-0878/MAR. During the work M.C. was supported financially by a FPI followship from the MYCT of the Spanish Government

A composite quantitative index for the percentage of primary production required to sustain fisheries and the average trophic level of catch (%PPR–TLc) was employed to develop ecosystem-based reference functions suitable for fisheries management. Established ecosystem models, characterized by pairs of %PPR–TLc, were classified as either sustainably exploited or ecosystem overfished, on the basis of the results of factorial correspondence analysis applied to selected ecological indices, and on information from various sources. Canonical discriminant analysis of these pairs was applied to establish the discriminant function to separate the two exploitation classes. Next, reference functions related to different probabilities of ecosystem overfishing were developed to obtain an operational framework for ecosystem-based fisheries management. Values of ecosystem-based maximum sustainable catches associated with different probabilities of belonging to a sustainable situation were calculated. Overall, results show that most current fishing scenarios entail high risks of ecosystem overfishing.