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The objective of the present study is to characterize the metabolic and antioxidant profile of white muscle of shi drum in two sites of the body, anterior dorsal (AM) and posterior dorsal (PM) portions. In addition, it will be analyzed the possible effect of starvation and a subsequent refeeding, with two different protocols, pair feeding and ad libitum. Activities of key enzymes of intermediary metabolism and of antioxidant enzymes, as well as lipid peroxidation, as an index of oxidative stress, were evaluated. The results indicate the existence of a regional asymmetry of the metabolic capacities of the white muscle of shi drum, which is likely related to the different contribution to swimming of the body regions examined. Starvation induces a metabolic depression that is more marked in those activities that support burst swimming in PM, while those activities supporting maintenance requirements are conserved. The greatest energy demands during starvation appear to lie in AM, which showed the highest oxidative metabolism rate. The increased use of fatty acids as energy source for AM leads to oxidative stress. A period of more than four weeks of refeeding for full restoration of metabolic capacities in AM is needed, probably related to the higher muscle mass located in this region. On the contrary, all enzyme activities in PM returned to control levels in both refeeding protocols, but pair feeding seems to be advantageous since compensatory growth has been taking place without signs of oxidative stress. This work was addressed to gain knowledge on the physiology of a promising fish species in aquaculture like shi drum. The results displayed here show how the starving and further re-feeding events could generate oxidative stress situations characterized by high lipid peroxidation levels which may influence negatively on the quality of the edible part of the fish. This study opens an interesting field on this fish species which deserves being investigated in the future., Graphical abstract fx1, Highlights • Research on the metabolism of a new fish species with potential aquaculture practices is depicted. • Starving and refeeding promote different metabolic alterations depending on body region of white muscle. • Fasting and refeeding may influence the quality of the edible part of the fish.

SUMMARY The posterior lateral line system (PLL) of teleost fish comprises a number of mechanosensory organs arranged in defined patterns on the body surface. Embryonic patterns are largely conserved among teleosts, yet adult patterns are highly diverse. Although changes in pattern modify the perceptual abilities of the system, their developmental origin remains unknown. Here we compare the processes that underlie the formation of the juvenile PLL pattern in Thunnus thynnus, the bluefin tuna, to the processes that were elucidated in Danio rerio, the zebrafish. In both cases, the embryonic PLL comprises five neuromasts regularly spaced along the horizontal myoseptum, but the juvenile PLL comprises four roughly parallel anteroposterior lines in zebrafish, whereas it is a simple dorsally arched line in tuna fish. We examined whether this difference involves evolutionary novelties, and show that the same mechanisms mediate the transition from embryonic to juvenile patterns in both species. We conclude that the marked difference in juveniles depends on a single change (dorsal vs. ventral migration of neuromasts) in the first days of larval life.

An international workshop on marine integrated contaminant monitoring (ICON) was organised to test a framework on integrated environmental assessment and simultaneously assess the status of selected European marine areas. Biota and sediment were sampled in selected estuarine, inshore and offshore locations encompassing marine habitats from Iceland to the Spanish Mediterranean. The outcome of the ICON project is reported in this special issue as method-oriented papers addressing chemical analyses, PAH metabolites, oxidative stress, biotransformation, lysosomal membrane stability, genotoxicity, disease in fish, and sediment assessment, as well as papers assessing specific areas. This paper provides a background and introduction to the ICON project, by reviewing how effects of contaminants on marine organisms can be monitored and by describing strategies that have been employed to monitor and assess such effects. Through the ICON project we have demonstrated the use of an integrating framework and gleaned more knowledge than ever before in any single field campaign about the impacts contaminants may have in European marine areas., SI

Marine litter is one of the main sources of anthropogenic pollution in the marine ecosystem, with plastic representing a global threat. This paper aims to assess the spatial distribution of plastic macro-litter on the seafloor, identifying accumulation hotspots at a northern Mediterranean scale. Density indices (items km–2) from the MEDITS trawl surveys (years 2013-2015) were modelled by generalized additive models using a Delta-type approach and several covariates: latitude, longitude, depth, seafloor slope, surface oceanographic currents and distances from main ports. To set thresholds for the identification of accumulation areas, the percentiles (85th, 90th and 95th) of the plastic spatial density distribution were computed on the raster data. In the northern Mediterranean marine macro-litter was widespread (90.13% of the 1279 surveyed stations), with plastic by far the most recurrent category. The prediction map of the plastic density highlighted accumulation areas (85th, 90th and 95th percentiles of the distribution, respectively, corresponding to 147, 196 and 316 items km–2) in the Gulf of Lions, eastern Corsica, the eastern Adriatic Sea, the Argo-Saronic region and waters around southern Cyprus. Maximum densities were predicted in correspondence to the shallower depths and in proximity to populated areas (distance from the ports). Surface currents and local water circulation with cyclonic and anticyclonic eddies were identified as drivers likely facilitating the sinking to the bottoms of floating debris, Sí

pdf, Thousands of potentially toxic chemical substances are introduced into the oceans every day. Even following decades of research and monitoring there is still a limited understanding of their effects on marine organisms and ecosystems. A complicating factor is the general lack of a direct relationship between elevated concentrations of contaminants in the tissues of marine organisms and effects. In addition, some biological responses have been shown to occur even at very low contaminant concentrations. A development and deployment of biological effects measurements (biomarkers and bioassays) along with analytical chemistry has increasingly been used as early warning signals of adverse environmental change in marine ecosystems. Contaminant-related biomarker responses include physiological or biochemical responses in organisms exposed to certain class of contaminants. Biomarker responses in fish from natural populations appear to be more sensitive than other methods, as they provide integrated information about contaminant exposure and effects as well as indicate acute pollution incidences. In vivo and in vitro bioassays contribute to our understanding of how pollutants affect living organisms but can also aid in deducing general mechanisms of action, to aid in categorization and overall assessment of effects. Fish is the most diverse class of vertebrates and can bridge human and ecological health in ecotoxicology studies. Benthic fish are suitable organisms for marine chemical pollution studies and the assessment of its health is it is not only an issue of conservation ecology but has clear links to utilisation of marine resources and human health. The main aims of this thesis were to clarify sublethal effects of environmental chemical contaminants on biological responses in three benthic fish species (Lepidorhombus boscii, Callionymus lyra and Mullus barbatus) from Spanish marine areas as well as to develop the use of contaminant-related biological responses in fish into an integrated framework for future Spanish pollution environmental monitoring programmes. This thesis comprises five scientific papers [I-V], all of which have been published in peer-reviewed international journals. Benthic fish were sampled under different field scenarios: i) from the northern Spanish shelf shortly after a medium oil spill ii) and repeatedly in the same area over a period of three years, iii) from chronically polluted areas on the Spanish Mediterranean inner shelf iv) and from the Mar Menor coastal lagoon (SE Spain). In all scenarios, fish were also simultaneously sampled from reference areas to allow a direct comparison. Standardised protocols were developed and implemented to minimise variability due to environmental and biological factors. In addition to direct use, the methods were evaluated and data from both monitoring and laboratory studies used to develop a framework for monitoring contaminants in marine ecosystems. The biological measurements investigated as part of this thesis comprised validated contaminant-related biomarkers, such as detoxification enzymes related to biotransformation phase I, e.g. ethoxyresorufin-O-deethylase activity (EROD) and biliary concentrations of hydroxylated metabolites of polyaromatic hydrocarbons (PAHs). Other contaminant-related biomarkers, whose applicability in marine fish is still under discussion and need further research, such as enzymes related to the organic xenobiotic biotransformation phase II (gluthatione-S-transferase activity (GST)), antioxidant enzymes (glutathione reductase (GR) and catalase (CAT)), metallothionein (MT) and DNA integrity were also studied. In addition, the in vitro ER-LUC reporter gene assay was used as a screening tool to estimate the total exposure to estrogenic active compounds in bile from fish collected in different areas as well as the estrogenic potency of hydroxylated PAHs and alkylphenols. Chapter 2 presents results from analyses of a range of hepatic biomarker responses five months after the Prestige oil spill using the two benthic fish species four-spot megrim, L. boscii, and the dragonet, C. lyra. The fish were collected from different areas along the northern Iberian shelf, to clarify the spatial extent of effects from the spill, as well as species-dependent responses [paper I]. No data were available for the concentration of chemical contaminants in the fish at the time of the study. Biomarker responses did however suggest that fish from some areas were affected by existing chronic pollution before the Prestige oil spill happened. Due to the lack of pre-spill biomarker data from the available species and this region, it was not possible to directly attribute biological effects observed in fish to the petroleum hydrocarbon components of the spilled oil. As a follow-up, Chapter 3 is a study to determine whether biomarker responses, in the same fish species, would vary over the immediate years following the Prestige oil spill [paper II]. The results indicated significantly decreasing hydrocarbon-associated biological responses over time and a subsequent recovery to presumed baseline levels. Overall, biomarker responses were in agreement with oil slick trajectories and the spatial distribution of tar aggregates found on the bottom shelf after the accident. The results of these studies showed that sublethal effects in fish were lasting for at least 2-3 years following the spill and they have been the first to show that an oil spill in open waters may affect benthic fish species hundreds of kilometres away. Chapter 4 presents the guideline document that was prepared to formalise the sampling design, species selection and the selection of appropriate biological effects techniques. The guideline focused particularly on toxicity assessment and strategies for monitoring biological effects associated with oil spills, with particular reference to European coastal waters [paper III]. The guideline document concluded that it is critical to have ongoing effects-based biomonitoring programmes in areas with high risk of oil-spill accidents. In Chapter 5, an integrated study was used to clarify whether contaminant concentrations in chronically polluted coastal areas in the Iberian Mediterranean inner shelf were at levels that cause adverse health effects in the benthic fish Mullus barbatus [paper IV]. The study combined chemistry in biota and surface sediments, biomarker responses as well as reproductive and nutritional physiological indicators. The study included a coastal area dominated by metal contamination (Portmán). The results showed alterations of some biomarkers, i.e. EROD, DNA integrity, muscle lipid content and gonadosomatic index, in fish from the more contaminated areas, although responses were not dramatic. The contaminant body burden in fish only partly reflected the presence of the same contaminants in the sediments of the study areas, presumably due to varying bioavailability and biotransformation capacity of the fish. Finally, Chapter 6 presents an integrated chemical and biological study to assess exposure to estrogenic contaminants to male fish [paper V]. The use of the in vitro ER-LUC reporter gene assay combined with chemical analyses in bile extracts highlighted some of the challenges using chemical analyses in that only a minimal fraction of the total estrogenic activity observed in male fish could be explained by the observed concentrations of estrogenic substances included in the chemical analyses. The results reported in chapter 2 and 3 have shown that L. boscii and C. lyra are appropriate species for monitoring programmes along much of the northern Iberian shelf. Similarly, the results reported in chapter 5 and 6 support the use of M. barbatus as a target species for monitoring programmes in Spanish Mediterranean waters. Interspecies differences in constitutive levels of biomarker responses were found for the three species, particularly for EROD activity and catalase activity. Results obtained in this thesis made it possible to establish preliminary assessment criteria (AC) for EROD activity in the three studied species and preliminary baseline levels of PAHs bile metabolites and bile estrogenicity in M. barbatus. A general discussion of the studies included in the thesis as well as recommendations for future biomonitoring programmes of chemical pollution in marine Spanish waters can be found in Chapter 7. Final concluding remarks and future perspectives are presented in Chapter 8.

Marine Spatial Planning (MSP) is a relatively new approach to ocean management and has been widely implemented worldwide. Ideally, MSP should be established as a public process that analyzes and distributes human activities across space and time to achieve ecological, economic and social goals, which historically have been accomplished exclusively in the political arena. However, in most cases MSP seems to be driven primarily by economic interests rather than by sociocultural goals. In this paper, we discuss how integrating the missing sociocultural layers into MSP can help to reduce governance rigidity, promote adaptability in decision-making, support environmental justice, and improve MSP acceptance and uptake. In particular, we focus on identifying possible points of connection between MSP and frameworks based on social-ecological system theory, including co-management and other democratic and empowering alternatives. We conclude by proposing a new definition of the MSP process that is more inclusive, and mindful of users’ rights and sociocultural objectives. If we bridge the gap between the dominant economic rhetoric and a de facto sociocultural-ecological system approach, we are likely to improve the chances of the MSP process succeeding on both the human and nature fronts., SI

Natural resources management deals with highly complex socioecological systems. This complexity raises a conundrum, since wide-ranging knowledge from different sources and types is needed, but at the same time none of these types of knowledge is able by itself to provide the basis for a viable productive system, and mismatches between the two of them are common. Therefore, a growing body of literature has examined the integration of different types of knowledge in fisheries management. In this paper, we aim to contribute to this ongoing debate by integrating the evolutionary theory of innovation—and specifically the concept of proximity—and the theory of perception. We set up a theoretical framework that is able to explain not only why the different types of knowledge differ, but also why they should differ and why this divergence is useful to develop fisheries management. This framework is illustrated through a well-known complex scenario, as was the implementation of the Landing Obligation (LO) in Europe. We conclude that diversity (distance) between types of knowledge is essential for interactive learning, innovation, the incorporation of new ideas or to avoid lock-in, etc. At the same time, cognitive, institutional, geographical, etc. proximity is needed for effective communication, participation and dialogue, SI

The impact of acute and chronic marine pollution on the population changes of individual fish remains mostly unknown. In this paper, we share our study and review similar published work, emphasising fish health monitoring in European Seas and illustrating it using case studies. Arguably, an integrative approach is needed to assess the impact on population of chemical contaminants, beginning with field observations and complemented with experimental (laboratory and mesocosm) studies and modelling. Field surveys and monitoring using fish biomarkers should be intensified and ideally integrated with population statistics and fish ecology knowledge. Moreover, the indirect effects of chemicals – altering ecosystem functions – and the monitoring of immunological biomarkers and fatal diseases in wild fish populations should receive more attention, Sí

The impact of acute and chronic marine pollution on the population changes of individual fish remains mostly unknown. In this paper, we share our study and review similar published work, emphasising fish health monitoring in European Seas and illustrating it using case studies. Arguably, an integrative approach is needed to assess the impact on population of chemical contaminants, beginning with field observations and complemented with experimental (laboratory and mesocosm) studies and modelling. Field surveys and monitoring using fish biomarkers should be intensified and ideally integrated with population statistics and fish ecology knowledge. Moreover, the indirect effects of chemicals – altering ecosystem functions – and the monitoring of immunological biomarkers and fatal diseases in wild fish populations should receive more attention., SI

This paper reports a full assessment of results from ICON, an international workshop on marine integrated contaminant monitoring, encompassing different matrices (sediment, fish, mussels, gastropods), areas (Iceland, North Sea, Baltic, Wadden Sea, Seine estuary and the western Mediterranean) and endpoints (chemical analyses, biological effects). ICON has demonstrated the use of a framework for integrated contaminant assessment on European coastal and offshore areas. The assessment showed that chemical contamination did not always correspond with biological effects, indicating that both are required. The framework can be used to develop assessments for EU directives. If a 95% target were to be used as a regional indicator of MSFD GES, Iceland and offshore North Sea would achieve the target using the ICON dataset, but inshore North Sea, Baltic and Spanish Mediterranean regions would fail., SI

Understanding the status of contaminants in the marine environment is a requirement of European Union Directives and the Regional Seas Conventions, so that measures to reduce pollution can be identified and their efficacy assessed. The international ICON workshop (Hylland et al., 2017) was developed in order to test an integrated approach to assessing both contaminant concentrations and their effects. This paper describes and assesses the concentrations of trace metals, polycyclic aromatic hydrocarbons, and polychlorinated biphenyls in sediments, mussels, and fish collected from estuarine, coastal and offshore waters from Iceland to the Mediterranean Sea. For organic contaminants, concentrations progressively increased from Iceland, to the offshore North Sea, to the coastal seas, and were highest in estuaries. Metals had a more complex distribution, reflecting local anthropogenic inputs, natural sources and hydrological conditions. Use of internationally recognised assessment criteria indicated that at no site were concentrations of all contaminants at background and that concentrations of some contaminants were of significant concern in all areas, except the central North Sea., SI

Gilthead seabream and European sea bass are two of the most commonly farmed fish species. Larval development is critical to ensure high survival rates and thus avoid unacceptable economic losses, while nutrition and immunity are also important factors. For this reason this paper evaluates the ontogenetic development of seabream and sea bass digestive and immune systems from eggs to 73 days post- fertilisation (dpf) by assessing the expression levels of some nutrition-relevant (tryp, amya, alp and pept1) and immune-relevant (il1b, il6, il8, tnfa, cox2, casp1, tf, nccrp1, ighm and ight) genes. The results point to similar ontogenetic development trends for both species as regard nutrition and differences in some immunity related genes., SI

In the present paper, we describe the performance of a bite-and-pull feed-demand system adapted to the behavior of European sea bass. The system is activated by the fish biting and pulling on, which generates an electrical signal that triggers the feed distributor. Experiment I was designed to test the sensor under laboratory conditions, using four groups of four naive fish per sensor (non-trained fish, NTF) and eight groups of four fish per sensor (small groups) that had been trained to use the system 1 year earlier (TF). Experiment II compared the bite-and-pull trigger (BPT) with a screened hanging-rod trigger (ST) using 16 groups of 48 sea bass per sensor (medium groups) under laboratory conditions. Experiment III evaluated the performance of the BPT sensor under farming conditions using four groups of 1000 sea bass per sensor (large groups) held in sea cages. Some of the advantages of the BPT sensor over other sensors are: (1) a shorter learning period, 11-12 days in exp. I, 1-2 day in exp. II and 1 day in exp. III; (2) absence of temporal constraints, allowing sea bass to feed at night (60% of nocturnal demands in exp. II; 23% and 47% of nocturnal demands in September and February, respectively, exp. III); (3) prevents accidental activation by fish, wind or waves; (4) low feed waste when reward level is set correctly; and (5) low costs, durability, and easy replacement of its components. All these features make the BPT a useful system for sea bass self feeding in sea cages.

Bone resorption in the first spine of the first dorsal fin of Atlantic bluefin tuna (ABFT) has long been considered for age estimation studies. In the present paper spine bone resorpion was assessed in wild (aged 1 to 13 years) and captive-reared (aged 2 to 11 years) ABFT sampled from the Mediterranean Sea. Total surface (TS), solid surface (SS) and reabsorbed surface (RS) were measured in spine transverse sections in order to obtain proportions of SS and RS. The spine section surface was found to be isometrically correlated to the fish fork length by a power equation. The fraction of solid spine bone progressively decreased according to a logarithmic equation correlating SS/TS to both fish size and age. The values ranged from 57% in the smallest examined individuals to 37% in the largest specimens. This phenomenon was further enhanced in captive-reared ABFT where SS/TS was 22% in the largest measured specimen. The difference between the fraction of SS of wild and captive-reared ABFT was highly significant. In each year class from 1- to 7-year-old wild specimens, the fraction of spine reabsorbed surface was significantly higher in specimens collected from March to May than in those sampled during the rest of the year. In 4-year-old fish the normal SS increase during the summer did not occur, possibly coinciding with their first sexual maturity. According to the correlations between SS/TS and age, the rate of spine bone resorption was significantly higher, even almost double, in captive-reared specimens. This could be attributed to the wider context of systemic dysfunctions occurring in reared ABFT, and may be related to a number of factors, including nutritional deficiencies, alteration of endocrine profile, cortisol-induced stress, and loss of spine functions during locomotion in rearing conditions., SI

Marine protected areas (MPAs) may be important for protecting the marine environment, but they may also have substantial socio-cultural impacts about which very little is currently known, or acknowledged. In the Mediterranean, few data are available on the socio-economic consequences of MPAs. The present study reviews the existing data on MPAs in Spain, France, Italy and Greece. A general increase in tourist activities in Mediterranean MPAs is evident, as are increases in the abundances of larger fish species, although there are no data indicating yields for fisheries increase adjacent to MPAs. A large increase in the number of divers and vessels using MPAs has already had impacts on natural benthic communities as a result of diver damage, mooring and the feeding of large fish by divers. Emphasis has been given in only a few MPAs to promoting public awareness of these impacts. Although the conservation of nature should be considered the fundamental objective of MPAs, neglecting their social, cultural and economic impacts has at times led to poor local consensus, if not hostility. We believe that planning and managing MPAs should be conducted on a multidisciplinary basis. Nonetheless, no single model can be considered valid for the whole Mediterranean. The very variable characteristics of coastal areas, from those of small uninhabited islands to those of cities, require different weightings to be assigned for each factor in order to achieve a durable equilibrium and realize the original objectives of each MPA. Only with such flexibility of management will it be possible to reach a greater understanding of the MPA system and create a lasting consensus in favour of conservation, a consensus which would mean an overwhelming majority of people actively avoiding damaging nature and preventing others from doing so. This paper was realized with funds from the EU CEC DGXII–MAST III contract number: MAS3-ct97–0155.

Alcohol polyethoxylates (AEOs) are the most commercially important type of nonionic surfactants, used in a wide variety of products such as household cleaning detergents, industrial cleaners, textiles, adjuvants in pesticides, wetting and dispersing agents, and emulsifiers. Our main objective in this work was to develop a methodology for the extraction, isolation and analysis of these compounds and their main degradation products and precursors (polyethylene glycols, PEGs) in solid environmental matrices. First, analytes were extracted by pressurized liquid extraction (PLE) using methanol at 120 °C as solvent and 3 cycles (5 min per cycle). Clean-up and concentration of the extracts were carried out by solid-phase extraction (SPE), using Oasis HLB cartridges and a mixture dicloromethane/methanol 1:1 as eluting solvent. Recovery percentages were usually between 54% and 106% for most compounds. Identification and quantification of analytes were performed using a liquid chromatography–mass spectrometry (LC–MS) system equipped with an electrospray interface (ESI) operating in positive ionization mode. Water content, cone voltage and adduct formation were optimized to this end. Limits of detection were usually below 50 ng g−1, being higher for some shorter ethoxymers (>100 ng g−1) because of poor ionization. Finally, the protocol proposed here was applied to the determination of the concentration of AEOs and PEGs in selected surface sediment samples collected in Mar Menor Lagoon (Murcia, Spain). In this sense, this paper presents some of the first data relative to the occurrence of these analytes in coastal sediments, showing relatively high concentrations of PEGs (up to 9000 ng g−1) compared to those measured for AEOs (, Sí

Since 1995, bluefin tuna (Thunnus thynnus) have been caught by purse seine in order to place the live fish in floating cages, feed them during various months with fish and pelagic cephalopods and later kill them for shipment mainly to the Japanese market. As a result of this practice, the natural stocks of this species are in an overfished state and therefore it has been necessary to implement catch limits (TACs). Since the tunas cannot be manipulated at the time of their capture, the estimate of the biomass of tunas caught must be carried out by visual methods using video cameras that are placed at the time when the tunas are transferred from the purse seine net to the towing cage. Therefore, there are no direct data on the catch until the animals are killed some months later, when evidently there is a variation in their weight. On the other hand, the regulation of the fishery requires immediate knowledge of the catch in order to close the fishery when the quota has been reached. This paper proposes the development of a system that permits estimating the number and the biomass of bluefin tunas by acoustic means, both at the time of transfer as well as during their fattening in the floating cages. 0

[EN] In this paper, an experimental setup to estimate the biomass of caged bluefin tuna (Thunnus thynnus) in the Spanish Mediterranean coast is presented. Aims are to monitor individual tuna during all stages of growth, to control the transfer of fish caught in purse seines to towing cages and to be able to estimate the total number of specimens and the biomass transferred. To do this, we propose a combined system of acoustic and optical techniques (both non-intrusive), in order to obtain direct values of acoustical target strength (TS) and information on the orientation of tuna inside the acoustic beam and their size. To achieve complete information, ventral and dorsal acoustic measurements are done using in a first attempt a multiplexed scientific echosounder with two 200 KHz split-beam transducers, while a stereoscopic video system provides optical information and allows estimating the size and the weight of the specimens. Preliminary results indicate that this combined use of techniques provides precise information to determine the TS as a function of fish orientation and for proper monitoring of tuna in floating cages., [FR] Le présent document décrit une expérience visant à estimer la biomasse du thon rouge mis en cages (Thunnus thynnus) sur la côte méditerranéenne espagnole. Le but recherché est de faire un suivi de chaque thon pendant tous les stages de la croissance, de contrôler le transfert des poissons capturés par les senneurs vers les cages des remorqueurs et de pouvoir estimer le nombre total de spécimens et la biomasse transférée. A cette fin, nous proposons un système combiné de techniques acoustiques et optiques (les deux non invasives), en vue d'obtenir des valeurs directes de la force acoustique cible (TS) et des informations sur l'orientation des thons à l'intérieur du rayon acoustique, ainsi que sur leur taille. Afin d'obtenir des informations complètes, des mesures acoustiques ventrales et dorsales sont réalisées à l'aide, tout d'abord, d'un échosondeur scientifique multiplexe doté de deux transducteurs de type split beam de 200 KHz, tandis qu'un système vidéo stéréoscopique fournit des informations optiques et permet d'estimer la taille et le poids des spécimens. Les résultats préliminaires indiquent que cet emploi combiné de techniques fournit des informations précises visant à déterminer la force cible comme une fonction de l'orientation des poissons et à effectuer un suivi adéquat des thons dans les cages flottantes., [ES] En este documento se presenta un diseño experimental para estimar la biomasa de atún rojo introducido en jaulas (Thunnus thynnus) en la costa española mediterránea. Los objetivos son realizar un seguimiento de los atunes a nivel individual, durante todas las fases de crecimiento, controlar la transferencia de ejemplares capturados por los cerqueros a las jaulas de remolque y estimar el número total de ejemplares y la biomasa transferida. Para ello, se propone un sistema combinado de técnicas acústicas y ópticas (ambas no intrusivas) con el fin de obtener valores directos de la fuerza de la señal acústica (TS) e información sobre la orientación de los atunes dentro del haz acústico y sobre su talla. Para conseguir información completa, las mediciones acústicas dorsales y ventrales se realizaron utilizando en un primer intento ecosonda científica multiplexeada con dos transductores de 200 KHz con haz dividido, mientras que el sistema de vídeo estereoscópico proporciona información óptica y permite estimar la talla y peso de los ejemplares. Los resultados preliminares indican que este uso combinado de técnicas proporciona información precisa para determinar la TS como una función de la orientación de los peces y para realizar un seguimiento adecuado de los atunes en las jaulas flotantes.

There is currently a global call for more use of an ecosystem approach to fisheries management (EAFM) to provide a holistic view of ecosystem–fisheries interactions. Trophic indicators could therefore be used to support the implementation of an EAFM by providing information on the state of the ecosystem. In this paper we propose a set of indicators such as the marine trophic index (MTI), the fishing in balance (FiB), the cutmarine trophic index (cutMTI) and the pelagic/demersal index (P/D) to assess the dynamics and the trophic changes in the Black Sea large marine ecosytem from 1970 to 2005. Our analysis shows a heavily exploited ecosystem where overfishing and anthropogenic eutrophication are probably responsible. The decline of the MTI, cutMTI and FiB together with the rising trend of the P/D index could be interpreted as a fishing down marine food web process with a strong decrease in abundance of high trophic level species and a considerable increase of low trophic level species. Key words: Trophic indicators, Ecosystem approach to fisheries management, Black Sea., Cada vez son más frecuentes las iniciativas para la aplicación de un enfoque del ecosistema para la gestión de la pesca (ecosystem approach to fisheries management, EAFM) que proporciona una visión holística de las interacciones entre la pesca y el ecosistema. Los indicadores tróficos pueden ser herramientas ideales para la aplicación de EAFM proporcionando información sobre el estado del ecosistema. En este trabajo se propone un conjunto de indicadores tales como el índice trófico marino (MTI), el índice pesca en equilibrio (FiB), el índice trófico marino rebajado (cutMTI) y el índice pelágicos/demersales (P/D) para evaluar la dinámica y los cambios tróficos en el Mar Negro desde 1970 hasta 2005. Nuestro análisis muestra un ecosistema muy explotado, donde la pesca excesiva y la eutrofización antropogénica son probablemente los responsables. El decremento en la tendencia del MTI, el cutMTI y el FiB conjuntamente con el incremento de la proporción P/D, se podría interpretar como una situación de la red trófica marina debida a la sobrepesca (fishing down marine food weeb situación). Este fenómeno implica una fuerte disminución en la abundancia de las especies de alto nivel trófico y un considerable aumento de las especies de bajo nivel trófico. Palabras clave: Indicadores tróficos, Enfoque del ecosistema para la gestión de la pesca, Mar Negro.

Depending on whether they are reared in cages or in the open sea and depending on the method of capture (electroslaughtering, shooting, etc.), differences are observed and changes take place in the organic nature of Blue Fin Tuna (Thunnus thynnus) meat, affecting appearance and quality. These changes are caused by an increase and accumulation of lactate, which negatively affects the quality. This drop in quality translates into loss of value of the meat in Japanese tuna markets (Tsukiji and Sashimi markets are the main destinations of tuna captured off the southeast coast of Spain). In order to evaluate these changes, Japanese experts are employed to carry out visual inspections, which therefore constitute a subjective assessment. This paper describes the development of an automated visual inspection system that can analyze, model and detect these changes. The ultimate aim is to establish quality indicators and classifiers that will accompany tuna meat from the time of capture and so make it possible to track this product in the main tuna meat export markets. In this way, we can establish a connection between variation of tuna meat quality and the feeding and slaughtering methods used, thus providing feedback to the fattening and slaughtering processes so as to improve the global quality of Blue Fin Tuna catches.

With the increasing economic importance of bluefin tuna (BFT) (Thunnus thynnus) and the need to supply a market on demand, the number of tuna farms is growing. This paper presents the results achieved in the improvement of tuna meat quality when slaughter on tuna farms was carried out using electrostunning and electrofishing techniques which have been used with small freshwater fishes for a century. This method was chosen because it offers a number of advantages: selection capacity and low stress level for tuna. Due to the large difference between freshwater and seawater conductivity, the discharge is applied using a harpoon rather than by generating an electric field. This study compares the meat quality obtained using different waveforms. Meat quality is assessed on the basis of two parameters: meat colour score and spinal injuries score. The waveforms tested were: constant current, high frequency pulsed direct current, complex pulse system, low frequency pulsed direct current, regulated alternating current and mixed signal. Only some of these had been tested in freshwater. According to the tests reported, only one of all the waveforms used in freshwater electrostunning was effective in seawater—that is the low frequency pulsed direct current, which caused moderate injuries. However, other waveforms which had not been tested in freshwater proved more effective. The best results were achieved with a mixed pulsed direct current and alternating current signal, which produced a reasonable quality level with moderate voltage and current and therefore has a low power requirement.

9 páginas, 3 figuras, 4 tablas. [EN] The present paper reports the results of an interlaboratory variability study of a bioassay using larval stages of the marine sea urchin Paracentrotus lividus. This exercise was developed in two different phases and included four laboratories, each of which determined the toxicity of six sediment samples. The samples were collected from different Spanish ports and were characterized by exposing sea urchin embryos for 48 h to sediment elutriates. Phase I was used to redesign test parameters and to avoid possible interfering factors when interpreting test results. Laboratories were more homogeneous in the classification of sediments according to the toxic responses in Phase II despite the high variability of the elutriate testing protocols. Based on our results, the test seems suitable to characterize dredged material, the interlaboratory variability being similar to that found for other bioassays in previous studies. [ES] El presente trabajo resume los resultados del ejercicio realizado para estudiar la variabilidad interlaboratorio del ensayo con estadios larvarios del erizo de mar Paracentrotus lividus. Este ejercicio, que se desarrolló en dos fases distintas, incluyó cuatro laboratorios cada uno de los cuales estudió la toxicidad de las seis muestras de sedimento distribuidas. Las muestras, provenientes de distintos puertos de la costa española, se caracterizaron mediante la exposición de embriones del erizo de mar Paracentrotus lividus durante 48 h a los lixiviados de los sedimentos. La Fase I se utilizó para rediseñar las condiciones del ensayo y evitar posibles factores de confusión al interpretar los resultados. Los resultados de la Fase II fueron más homogéneos al clasificar las muestras según la toxicidad registrada, a pesar de la variabilidad en los protocolos de obtención y ensayo de los lixiviados. De acuerdo con estos resultados, el ensayo es adecuado para la caracterización de este tipo de muestras con una variabilidad interlaboratorio similar a la encontrada para otros bioensayos en estudios interlaboratorio previos. Este estudio fue parcialmente desarrollado bajo subvención del Ministerio Español de Ciencia y Tecnología (REN2002_01699/TECNO). El diseño de los ensayos agudos para la caracterización de materiales de dragado se realizó en un proyecto conjunto entre el CEDEX y la Universidad de Cádiz (2001 y 2003). MC Casado-Martínez agradece la financiación del Ministerio Español de Educación y Ciencia en el programa de becas de Formación de Personal Investigador (FPI).

Red mullet (Mullus barbatus, Linnaeus, 1758) is one of the fish species used as bioindicator in the Mediterranean Pollution Monitoring Programme (MEDPOL). This paper presents the results of a field study on the induction of hepatic metallothioneins (MT) in red mullet as specific biomarker of metal contamination. Specimens of M. barbatus were collected in six areas with different degrees of anthropogenic activities along the Iberian Mediterranean coast. The environmental exposure to heavy metals of the populations was determined through the analyses of surface sediments collected in each study area. The MT levels obtained showed statistically significant differences between areas, but not between specimens of different sex. Furthermore, the highest MT levels were found in the most polluted areas. Hepatic MT levels in red mullet reflect the metal contamination present in surface sediments, especially for Cu, for which a significant linear regression was found. The MT levels are better correlated with Cu and Cd concentrations than with Zn and Hg concentrations. The MT values obtained in this study are the first to be reported for this species in the Iberian Mediterranean and they should help in the interpretation of MT levels and to establish MT background levels for M. barbatus in the western Mediterranean.

Fresh water electrofishing techniques have been adapted in order to be used in sea water for electrofishing of some fish species such as the Bluefin Tuna (BFT). The effect of the current flow from the harpoon through the spine may damage it, decreasing the final quality of the meat obtained. This paper describes a project that approaches the development of a non conventional electronic power converter that allows to study different waveforms and its effect on the quality of the product, as well as an automatic system of visual inspection for the objective evaluation of shape and the quality of tuna meat., Techniques de pêche électrique: Abattage et analyse de la qualité du thon rouge. Les techniques de pêche électrique en eau douce ont été adaptées afin d´être utilisées en eau de mer pour la pêche électrique de quelques espèces de poissons tels que le thon rouge. Le passage du courant du harpon à travers la colonne vertébrale peut causer des dommages, et diminuer la qualité finale de la viande obtenue. Cet article décrit un project qui envisage le développment d´un convertisseur électronique de puissance non conventionnel qui permette d´étudier différentes formes dónde et leur effet sur la qualite du produit, ainsi qu´un systéme automatique d´inspection visuelle pour l´évaluation objetive de la forme et la qualité de la viande de thon., Sí