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Increasing sea temperature is a driver of change for many fish traits, particularly for fast-growing epipelagic species with short life spans. With warming, altered spawning phenology and faster growth may produce substantially larger body sizes of the new cohort, affecting fishery productivity. We present an individual-based model (IBM) that predicts the distribution of fish length at catch under observed and projected thermal scenarios, accounting for mortality, temperature-dependent spawning phenology, temperature- and photoperiod- dependent growth. This IBM was demonstrated with Coryphaena hippurus (common dolphinfish), a circumglobally-distributed and highly thermophilic species sustaining commercial and recreational fisheries where it is present. The model projected a 13.2% increase in the average length at catch under marine heatwave conditions compared to the current thermal regime (1995–2005 average). Projections under RCP scenarios 4.5 and 8.5 by the end of the century led to 5.1% and 12.8% increase in average length, respectively. Furthermore, these thermal scenarios affected spawning phenology differently, producing higher variance in body size under RCP 8.5 scenario with respect to marine heatwave conditions. This study highlights how the environmental effects of climate change can alter the distribution of species length at catch., The present paper is part of the CERES project (H2020, EU 678193). Part of the data was obtained from the FAO-Copemed and FAO-Copemed II projects (http://www.faocopemed.org/). This study has been conducted using E.U. Copernicus Marine Service Information. V. Moltó acknowledges a predoctoral grant funded by the Regional Government of the Balearic Islands and the European Social Fund, A. Ospina Álvarez was supported by H2020 Marie Skłodowska-Curie Actions (746361), and S. Pérez-Mayol salary was founded by PN Project DREAMER (CTM2015-66676-C2-1-R). We also acknowledge Andreina Fenech, Marie Louise Pace, and Roberta Mifsud from the Department of Fisheries and Aquaculture of Malta for the data collection and provision.

The spatial distribution of deep-sea fishes is commonly related to major water masses or regional circulatory features that in turn may reflect differences in food-web structure and productivity. Aphanopus carbo is a benthopelagic species that undergoes horizontal and vertical migrations driven by spawning and by feeding, and for which a large-scale clockwise migration around the NE Atlantic is hypothesized. In this work, the adequacy of otolith microchemical composition used as tool to discriminate A. carbo specimens caught at different areas was investigated. Furthermore, potential birth areas and spatial pattern migration throughout the species life cycle were studied. Trace element concentration (TEC) in the otolith edge allowed the discrimination of the locations where specimens were caught and supported the separation between the northern and the southern distribution areas. The existence of two natal sources was suggested based on the separation of otolith core TEC into two groups. Longitudinal multivariate analyses applied to TEC data also sustained the separation of the otoliths into two main groups, but the mixing between them gives support to the species migratory hypothesis. The acceptance of both southern and northern spawning grounds and of migratory movements along the NE Atlantic in both northward and southward directions implies changes to the current migratory hypothesis that might be translated into new definitions of A. carbo stock structure and therefore fisheries management., This work was supported by the Portuguese Foundation for Science and Technology (FCT – Fundação para a Ciência e Tecnologia) [Grant SFRH/BD/64434/2009 to I. Farias]; the Portuguese Fisheries Operational Program (2007–2013) (PROMAR – Programa Operacional Pescas), co-financed by the European Fisheries Fund (EFF) (2007–2013), under project CERTIFICA (2011–2015), MSC Certification in Portugal - Acquiring the knowledge and studying the viability for its application to coastal and artisanal fisheries; and the Portuguese Government Development Investments and Expenses Program (PIDDAC – Programa de Investimentos e Despesas de Desenvolvimento da Administração Central) under the EU/DG Fisheries' Data Collection Framework (DCF).

The spatial and temporal variation of the early growth patterns (EGP) of anchoveta (Engraulis ringens), were analyzed and compared among three geographic areas, i.e., Northern zone (18–24°S); North-central zone (26–30°S) and Southern zone (33–42°S) off the Chilean coast over three years (i.e., 2015, 2016 and 2019). EGP were determined through otolith microstructure analysis for juveniles ranging from 2.0 to 12.0 cm in total length (TL), corresponding to ages from 28 to 187 days. The comparative growth analysis between the three study areas for the 2015, 2016 and 2019 cohorts showed significant differences in the Laird-Gompertz growth parameters and the absolute growth rate at the inflection point (0.67–1.11 mmd−1). A generalized additive models (GAM) was used to analyze changes in mean daily increment width profiles (IW) as related to the area, monthly cohort, sea surface temperature (SST) and Chlorophyll concentration (Chloa) as predictive variables. The GAM did not show significant difference in mean IW between northern and north-central areas (7.9 ± 3.9 vs 8.3 ± μm), although they significantly varied with respect the southern area, where the lower values of IW were found (5.6 µm). The GAM showed higher IW partial residuals when SST was above 14 °C and Chloa concentration was lower than 2 m gm−3. Overall results showed a high plasticity in the early growth pattern of E. ringens, indicating interannual and spatial variability, with SST playing a pivotal role across a wide latitudinal gradient off Chilean coast.

The European hake Merluccius merluccius is the third most valuable species for the North-East Atlantic and the Mediterranean fisheries. European hake has been rated as overexploited in the Mediterranean, thus careful management is advisable. Mediterranean hake is well-differentiated from Atlantic hake, but sub-population structure within the Mediterranean, and how this structure could be translated into stocks (operative management units), is still an elusive topic. Otolith shape and chemistry (concentration of trace elements) have been systematically used to distinguish fish stocks. Our aim was therefore to assess the discrimination capability (assigning fish to the correct geographical unit) of otolith shape and microchemistry at two geographical scales within the Mediterranean: (1) the official geographical subareas (GSAs), and (2) three larger units previously suggested by genetic markers (i.e., Western Mediterranean, Adriatic with Central Mediterranean, and Eastern Mediterranean). Two complementary analyses were completed because shape is more easily analyzed than chemistry. First, a large sample of juvenile hake (n = 1656) from 40 Mediterranean GSAs subunits was used for shape analysis. Second, a subsample of those fish (n = 154) from 10 GSAs was analyzed for both otolith shape and microchemistry. Irrespective of the type of data (shape and/or chemistry) and geographical scale (GSAs versus the 3-units), between-unit differences were always statistically significant. However, according to the large within-unit variability, discrimination capability was always poor but better at the GSA scale, and even better when both shape and microchemistry were combined. Moreover, unsupervised clustering methods (the number and limits of the units are data-driven and not a priori defined as above) failed to find an optimal structure. Overall, these results are fully compatible with the hypothesis of a continuous gradient, within which discrete spatial units cannot be safely recognized., Sílvia Pérez-Mayol's salary was co-funded by the Direcció General de Política Universitària i Recerca of the Balearic Government, Spain and the Consejo Superior de Investigaciones Científicas, Spain (TEC/001/2018). Thibault Kersaudy’s salary was funded by the MED_UNITs contract. This study was part of the MED_UNITs contract (Specific Contract No. 03EASME/EMFF/2017/1.3.2.3/01/ SI2.793201 -SC03– MED_UNITs).

Assessing the motivations and wildlife-related value orientations (WVOs) of outdoor recreations, such as recreational fishing (RF), is of key importance to understand the human dimensions of natural resource use and to inform management actions. Using a national random telephone survey, we contrasted the participation rate, the socio-economical profile, and the motivations and WVO of the participants of RF, outdoor recreation (OR), consumptive outdoor recreation (COR), and indoor recreation (IR) in Spain. Participation rates of the four subgroups were 6.6, 15.3, 49.4, and 28.4%, for RF, COR, OR, and IR, respectively. The four subgroups differed in socio-economic characteristics, with women being substantially less involved in RF compared to COR, OR, and IR. Moreover, we found higher incomes and educational degrees of the participants in the three outdoor modalities compared to IR. Motivations to engage in RF, COR, OR, and IR were different. Recreational fishers placed significantly more importance on the motives “to be close to nature,” “to experience tranquility,” “to get away from the usual demands of life,” “to relax psychically,” “to stay with family,” and “to get exercise” compared to the other recreational groups, being very different from the ones to practice IR. We did not find significant differences in the WVO among the participants of the four recreational activities. We conclude that recreational fishing is a widespread recreational activity in Spain, embedded in all the segments of the society, thereby generating substantial psychological benefits, which are not equally produced by other forms of indoor and outdoor recreation., JA was supported by the Ramón y Cajal Grant (Grant no. RYC2018-024488-I), funded by the Spanish Ministry of Science and Innovation (MICINN), and he also received funding from the CLOCKS R&D Project (grant no. PID2019-104940GA-I00) funded by the MICINN and the Agencia Estatal de Investigación, and the intramural research project, JSATS (Grant no. PIE202030E002) funded by the MICINN and the Spanish National Research Council (CSIC). RA acknowledges funding from the German Ministry of Education and Research (marEEshift: 01LC1826D, Aquatag 033W046A).

10 pages, 6 figures, 5 tables, supplementary material https://doi.org/10.3989/scimar.05106.007, [EN] The age and growth patterns of the mesopelagic fish Ceratoscopelus maderensis (family Myctophidae) of the western Mediterranean Sea were described throughout its entire life cycle (from larvae to adult stages) using the sagittae otoliths of 59 individuals collected in December 2009. Three characteristic zones were identified along the cross-section of the sagittae (larval, metamorphic and juvenile-adult zones). Assuming growth rings as daily increments, the age of the analysed individuals (from 3.5 to 64 mm standard length [SL]) would range from 7 to 332 days. The relationship between the number of increments and the fish SL was fitted to a von Bertalanffy growth model (SL=70.5899×(1–exp(–0.0501(t+2.6705))). The growth pattern of C. maderensis in the western Mediterranean Sea was similar to that reported for this species in the northeast Atlantic Ocean. Though from a body size of 40-45 mm SL, growth rates declined more slowly in individuals from the western Mediterranean Sea, growth differences between these individuals and those from the northeast Atlantic Ocean were not statistically significant. This study provides new insights into the age and growth patterns of one of the most abundant mesopelagic fish species in the Mediterranean Sea that have clear implications for the study and management of marine ecosystems, [ES] En el presente trabajo se describen la edad y los patrones de crecimiento desde la fase larvaria hasta la fase adulta del pez mesopelágico Ceratoscopelus maderensis (familia Myctophidae) del Mediterráneo occidental. Para ello, se analizó el otolito sagitta de 59 individuos capturados en diciembre de 2009. Se identificaron tres zonas en la sagitta, cada una de las cuales se corresponde con una fase del desarrollo ontogenético del pez: larvaria, metamórfica y juvenil-adulta. Asumiendo que los anillos de crecimiento son diarios, la edad de los individuos analizados (de 3.5 a 64 mm de longitud estándar [SL]) oscilaría entre 7 y 332 días. La relación entre el número de incrementos y la SL de los peces se ajustó al modelo de crecimiento de von Bertalanffy (SL=70.5899×(1–exp(–0.0501(t+2.6705))). El patrón de crecimiento de C. maderensisen el Mediterráneo occidental fue similar al previamente descrito para esta especie en el Noreste del Océano Atlántico. A pesar de que, a partir de 40-45 mm SL, las tasas de crecimiento disminuyeron más lentamente en los individuos del Medi-terráneo occidental, las diferencias de crecimiento entre estos individuos y los del Noreste del Océano Atlántico no fueron estadísticamente significativas. Los resultados de este estudio aportan nuevos conocimientos sobre la edad y el crecimiento de una de las especies más abundantes del Mar Mediterráneo, lo cual tiene claras implicaciones de cara al estudio y la gestión de los ecosistemas marinos, The authors are very grateful to the IDEADOS project (CTM2008-04489-C03-02) and for the technical sup-port offered by José Manuel Fortuño (ICM) and Silvia Pérez-Mayol of the Sclerochronology Service at IME-DEA (UIB-CSIC), With the funding support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S), of the Spanish Research Agency (AEI)

[EN] We determined the efficacy of marking the otoliths of three small-sized progenetic gobies to validate their increment periodicity. These small gobies have high mortalities and rearing difficulties, making direct validation difficult. The otoliths were marked by immersing the fish in a bath of alizarin red S. The fishes were euthanatized and the number of increments in their otoliths laid down after the fluorescent mark were counted and compared with the number of elapsed days. The results validated the daily periodicity of Aphia minuta and Pseudaphya ferreri. The high mortality hindered the validation of Crystallogobius linearis., [ES] Se determinó la eficacia en el marcado de los otolitos de tres góbidos progenéticos de pequeña talla con el fin de validar la periodicidad en la deposición de los incrementos de crecimiento. Estos pequeños góbidos presentan altas mortalidades y dificultades en su cría, por lo que la validación directa de su crecimiento es difícil. Los otolitos fueron marcados con rojo de alizarina S (ALR). Los peces fueron eutanasiados y el número de incrementos depositados después del marcaje con el colorante fluorescente se contó y comparó con el número de días transcurridos. Los resultados obtenidos validaron la periodicidad diaria para Aphia minuta y Pseudaphya ferreri. La elevada mortalidad impidió la validación en Crystallogobius linearis., SP’s salary was cofunded by the DGPUR of the Balearic Govern-ment and the CSIC. This contribution is a result of the “Unidad Asociada IMEDEA-LIMIA”.

[Background] Syngnathid fishes (Actinopterygii, Syngnathidae) are flagship species strongly associated with seaweed and seagrass habitats. Seahorses and pipefishes are highly vulnerable to anthropogenic and environmental disturbances, but most species are currently Data Deficient according to the IUCN (2019), requiring more biological and ecological research. This study provides the first insights into syngnathid populations in the two marine Spanish National Parks (PNIA—Atlantic- and PNAC—Mediterranean). Fishes were collected periodically, marked, morphologically identified, analysed for size, weight, sex and sexual maturity, and sampled for stable isotope and genetic identification. Due the scarcity of previous information, habitat characteristics were also assessed in PNIA., [Results] Syngnathid diversity and abundance were low, with two species identified in PNIA (Hippocampus guttulatus and Syngnathus acus) and four in PNAC (S. abaster, S. acus, S. typhle and Nerophis maculatus). Syngnathids from both National Parks (NP) differed isotopically, with much lower δ15N in PNAC than in PNIA. The dominant species were S. abaster in PNAC and S. acus in PNIA. Syngnathids preferred less exposed sites in macroalgal assemblages in PNIA and Cymodocea meadows in PNAC. The occurrence of very large specimens, the absence of small-medium sizes and the isotopic comparison with a nearby population suggest that the population of Syngnathus acus (the dominant syngnathid in PNIA) mainly comprised breeders that migrate seasonally. Mitochondrial cytochrome b sequence variants were detected for H. guttulatus, S. acus, and S. abaster, and a novel 16S rDNA haplotype was obtained in N. maculatus. Our data suggest the presence of a cryptic divergent mitochondrial lineage of Syngnathus abaster species in PNAC., [Conclusions] This is the first multidisciplinary approach to the study of syngnathids in Spanish marine NPs. Habitat preferences and population characteristics in both NPs differed. Further studies are needed to assess the occurrence of a species complex for S. abaster, discarding potential misidentifications of genus Syngnathus in PNAC, and evaluate migratory events in PNIA. We propose several preferential sites in both NPs for future monitoring of syngnathid populations and some recommendations for their conservation., Study funded by Proyecto Hippoparques (1541S/2015 and 1580S/2015; Organismo Autónomo de Parques Nacionales—OAPN, Ministerio de Agricultura, Alimentación y Medio Ambiente, Spain). Project 1580S/2015 was in charge of genetics.

The reproductive biology of two species of pipefish, Syngnathus typhle and S. abaster, was investigated in western Mediterranean coastal waters, through determination of sex-ratio and maturity state, and histological assessment of gonads, brood pouch and embryos of these little-known syngnathid species. A total of 22 S. typhle and 13 S. abaster individuals were collected by towing-net on shallow seagrass meadows (Posidonia oceanica and Cymodocea nodosa) at Balearic Islands (Spain). Overall sex-ratio (male : female) was 1.0 : 1.2 for S. typhle and 1.0 : 2.7 for S. abaster. Regarding maturity, all stages of females were sampled while only immature or brooding males were collected. Males with embryos in the pouch were found in summer for both species, and mature females of S. typhle were found in summer whereas mature females of S. abaster were found in winter and summer, suggesting that each species might have a different reproductive cycle. This study contributes to the knowledge on the reproductive biology of the two most abundant pipefish species in W-Mediterranean coastal waters, which might help for further restocking and conservation management strategies., This study was partly funded by Proyecto Hippoparques (1541S/2015 and 1580S/2015; Organismo Autónomo de Parques Nacionales Ministerio de Agricultura, Alimentación y Medio Ambiente, Spain).

Pipefish are a vulnerable and diverse group of ichthyofauna tightly associated with seagrass meadows, key habitats in shallow marine areas. Despite their charismatic role, the main ecological features, habitat, and diet of this group remain largely unknown. This study focuses on assessing pipefish habitat and feeding preferences, including different hosting seagrasses such as Posidonia oceanica and Cymodocea nodosa from the Balearic Islands, western Mediterranean. Four species (Syngnathus typhle, S. abaster, Nerophis ophidion, and N. maculatus) were found associated to different seagrasses. S. typhle and N. maculatus were more frequent in P. oceanica meadows, while S. abaster and N. ophidion in C. nodosa. Individuals of all species captured in P. oceanica were larger than those living in C. nodosa, suggesting a size-dependent habitat preference. Feeding preferences, however, were driven by prey availability and fish features, e.g., head/snout morphology. For the first time in the western Mediterranean, a thorough description of the diet and potential prey of this group was carried out. Epifaunal assemblages (potential prey) were dominated in both habitats by harpacticoid copepods and gammarid amphipods, and they were also the primary prey according to stomach contents of all species. These results can contribute to future pipefish conservation and management actions, such as targeting crucial habitat identification and designing culture and reintroduction protocols., This study was funded by the research Project “Singnátidos de los Parques Nacionales de las Islas Atlánticas y del Archipiélago de Cabrera (541S/2015)” awarded to CSIC by Organismo Autónomo Parques Nacionales (Ministerio de Agricultura, Alimentación y Medio Ambiente, Programa Estatal de I+D+i Orientada a los Retos de la Sociedad, Plan Estatal de Investigación Científica y Técnica y de Innovación 2013-2016). Additional support was provided by the joint Associated Unit IMEDEA-LIMIA (Laboratorio de Investigaciones Marinas y Acuicultura, Dirección General de Pesca y Medio Marino, Govern Illes Balears).

Background: Syngnathid fishes (Actinopterygii, Syngnathidae) are flagship species strongly associated with seaweed and seagrass habitats. Seahorses and pipefishes are highly vulnerable to anthropogenic and environmental disturbances, but most species are currently Data Deficient according to the IUCN (IUCN, 2019), requiring more biological and ecological research. This study provides the first insights into syngnathid populations in the two marine Spanish National Parks (PNIA –Atlantic- and PNAC –Mediterranean). Fishes were collected periodically, marked, morphologically identified, analysed for size, weight, sex and sexual maturity, and sampled for stable isotope and genetic identification. Due the scarcity of previous information, habitat characteristics were also assessed in PNIA. Results: Syngnathid diversity and abundance were low, with two species identified in PNIA (Hippocampus guttulatus and Syngnathus acus) and four in PNAC (S. abaster, S. acus, S. typhle and Nerophis maculatus). Syngnathids from both National Parks (NP) differed isotopically, with much lower δ15N in PNAC than in PNIA. The dominant species were S. abaster in PNAC and S. acus in PNIA. Syngnathids preferred less exposed sites in macroalgal assemblages in PNIA and Cymodocea meadows in PNAC. The occurrence of very large specimens, the absence of small-medium sizes and the isotopic comparison with a nearby population suggest that the population of Syngnathus acus (the dominant syngnathid in PNIA) mainly comprised breeders that migrate seasonally. Novel 16S rDNA haplotypes and sequence variants were detected for H. guttulatus, N. maculatus, S. acus, and S. abaster. Our data suggest the presence of a cryptic Syngnathus species in PNAC. Conclusions: This is the first multidisciplinary approach to the study of syngnathids in Spanish marine NPs. Habitat preferences and population characteristics in both NPs differed. Further studies are needed to assess potential species misidentifications of genus Syngnathus in PNAC, and migratory events in PNIA. We propose several preferential sites in both NPs for future monitoring of syngnathid populations and some recommendations for their conservation.

The common dolphinfish (Coryphaena hippurus) is an epipelagic thermophilic species with a worldwide distribution in tropical and subtropical regions that is characterized by its migratory behavior and fast growth rates. This species is targeted by artisanal small-scale and recreational fisheries in most regions where it is found. This paper updates and analyzes the global scientific knowledge on the biology and ecology of this species, which was last revised at a regional level 20 years ago. This review showed an increase in knowledge about the population structure and regional differences in biological traits, in parallel with a notable lack of mechanistic and even empirical knowledge about the ecology of this species, which hampers a good understanding of the population dynamics and the potential impacts of environmental change. This paper also updates the information about the Mediterranean dolphinfish fishery, where the main four countries that exploit this species deploy 30% of fish aggregation devices (FAD) worldwide. The results suggest, among other effects, some temporal synchronicity in landings across countries, potential interannual stock movement affecting inter-country catches, diverging trends in prices and insufficient quality in the estimates of fishing effort. The authors propose a suite of specific measures to ameliorate this lack of knowledge and to better manage this complex living resource., Vicenç Moltó acknowledges a predoctoral grant funded by the Regional Government of the Balearic Islands and the European Social Fund. This work was partially funded by two FAO Projects: CopeMed phase II “Coordination to Support Fisheries Management in the Western and Central Mediterranean” and MedSudMed “Assessment and Monitoring of the Fishery Resources and the Ecosystems in the Straits of Sicily”, both co-funded by the Spanish and the Italian Ministries of Agriculture, Fishery and Food, and by the Directorate-General for Maritime Affairs and Fisheries of the European Commission (DG-MARE). The work was partially supported by project CERES (H2020, EU 678193).

Background: Syngnathid fishes (Actinopterygii, Syngnathidae) are flagship species highly associated to seaweed and seagrass habitats of marine ecosystems biodiversity. Seahorses and pipefish are highly vulnerable to anthropogenic and environmental disturbances, but most species are currently Data Defficient by IUCN (IUCN, 2019), requiring more biological and ecological research. This study provides the first insights on syngnathid populations in two Spanish National Parks (PNIA –Atlantic- and PNAC –Mediterranean-). Fish were collected periodically, marked, morphologically identified, analyzed for size, weight, gender and sexual maturity, and sampled for further stable isotope and genetic identification. Due the scarcity of previous information, habitat characteristics were also assessed in PNIA. Results: Syngnathid diversity and abundances were low, with two species identified in PNIA ( Hippocampus guttulatus and Syngnathus acus ) and four in PNAC ( S. abaster , S. acus , S. typhle and Nerophis maculatus ). Syngnathids from both NPs differed isotopically, with much lower δ15 N in PNAC. The dominant species were S. abaster in PNAC and particularly S. acus in PNIA. Syngnathids preferred less exposed sites in macroalgal assemblages in PNIA and Cymodocea meadows in PNAC. In S. acus from PNIA, the occurrence of very large specimens, the absence of small-medium sizes and the isotopic comparison with a nearby population suggest that the population is mainly founded by breeders that migrate seasonally. Novel 16S rDNA haplotypes and sequence variants were detected for Hippocampus guttulatus , N. maculatus , S. acus, and S. abaster . Our data suggest the presence of a cryptic Syngnathus species in PNAC, Conclusions: This is the first multidisciplinary approach to the study of syngnathids in Spanish marine NPs. Habitat preferences and population characteristics in both NPs differed. Further studies are needed to assess potential misidentifications of Syngnathus genus in PNAC, and migratory events in PNIA. We propose several preferential sites in both NPs for future monitoring of syngnathid populations and some recommendations to undertake.

Mediterranean small-scale fleets catch a substantial amount of untargeted fish that are sold at a low market price. Most of these catches are pooled into mixed-fish boxes (MFBoxes), which are usually labeled and sold as mixed-fish commercial categories (MFCategories). In this paper, we describe the MFBoxes and the MFCategories from the small-scale fleet of Mallorca Island in terms of species composition, size distribution and economic value. We used (i) daily sales records of MFCategories between 2004 and 2015 and (ii) a sample of 141 photographs of MFBoxes, collected over one year (2009–2010). MFCategories represent a non-negligible fraction of the landings, between 18 and 51 tons/year which represents 100–300 K€/year. Some of the sampled MFBoxes were sold as one of the three identified MFCategories, which differ in species composition, size and average price (3.9 €/kg for the category LARGE MORRALLA, 2.2 €/kg for SMALL MORRALLA and 7.0 €/kg for VARIAT). However, more than half (52%) of the sampled MFBoxes were actually labeled and sold not as MFCategories but as one of the most abundant species in the box. This strategy might seem unprofitable because the market price is lower for MFBoxes sold as non-mixed categories than for non-mixed boxes of the same category. However, we observed that the label itself does not affect the selling price, but species composition does. Therefore, when sorting fish into boxes, fishers may be trying to optimize the tradeoff between not selling some low-priced fish and mixing them with other more valued fish. This alternative marketing strategy should be explored in depth and properly assessed, not only to maximize profits but also to promote a zero-discard European policy., This research received funding from the European Commission’s Horizon 2020 Research and Innovation Programme under Grant Agreement No. 634495 for the project Science, Technology, and Society Initiative to minimize Unwanted Catches in European Fisheries (MINOUW). OPMallorcaMar and the Federació Balear de Confraries de Pescadors are thanked for their support and collaboration. J.A. and M. C-R were supported through Juan de la Cierva post-doc grants (grants no. FJCI-2014-21239 and FJCI-2014-20374, respectively) funded by the Spanish Ministry of Economy and Competitiveness.

Although inferring habitat selection and movement in wild fishes using otolith microchemistry has been the subject of much debate, experimental results suggest that complex environmental vs. life history interactions affect the incorporation of certain chemical elements into otoliths. We hypothesized that under relatively homogeneous hydrographic conditions, individual life history trait strategies should dominate signals of geochemical signatures. We tested our hypothesis by analyzing individual chronologies of otolith signals of strontium to calcium (Sr:Ca) and barium to calcium (Ba:Ca) ratios in a sedentary coastal fish (Diplodus annularis). Two areas from the same northwest Mediterranean region with different levels of fishing pressure were sampled: (1) a no-take marine protected area where the “bigger-is-better” strategy should prevail (energy allocation is biased toward growth to compensate for high natural mortality at small sizes) and (2) a highly exploited population where the “smaller-is-better” strategy should dominate (energy allocation is biased toward reproduction to compensate for high fishing mortality at large sizes). Significant differences in reproduction vs. growth trade-offs were observed between the sub-populations. Sr:Ca and Ba:Ca chronologies were compared between back-calculated ontogenetic stages (larvae, juveniles and adults) and sub-populations/life histories using a general linear mixed model. The Sr:Ca chronology successfully reproduced the allocation of energy for growth or reproduction according to the life history strategy of the individual, whereas correlation between ontogeny and otolith microchemistry was less obvious for Ba:Ca. We contend that the direct and/or indirect (e.g., the removal of large predators) effects of fishing pressure on microchemical signals should receive more attention in field studies, as trade-offs between mortality and growth/reproduction might alter microchemical patterns under a given a set of conditions.

In this essay, I review my career in fish and fisheries, describing my work in the context of the ideas of the period and how they have changed with time. My experience may be interesting especially for other women from social backgrounds that do not promote competitive careers. The main lessons that I have learned are that to be persistent and ambitious, to associate with top scientist, and good persons too! is rewarding at several levels. Not to try to be the one in the spotlight but to recognize other people merits gives good results in the long run. Moreover, to take risks from time to time and explore new territories, like science administration in my case, helps to reinvent yourself and keep the intellectual interest alive. I would like to encourage young scientists to persevere, be resilient and take, from time to time, risky decisions. Maybe one does not become rich, but the mental challenges, the networking, the travel and the exceptional places and life experiences make you rich in many worthy ways! One does never get bored.

A widely accepted practice to maximize the survival of mandatory or voluntary released aquatic animals that have ingested hooks is to cut the line, leaving the ingested hook in thousands of fish, sharks, turtles and marine invertebrates worldwide. Recent evidence suggests that the chemical composition (mainly metals) of ingested hooks can potentially be absorbed and retained within soft tissues of fish and can subsequently have adverse effects on their health. In this study, we tested the hypothesis that hard tissues (otoliths) should also show a chemical signal of hooking. Using the mulloway (Argyrosomus japonicus) as a case study, we have compared the microchemistry compositions (Ba, Ca, Co, Cr, Mn, and Sr) of the otoliths measured by Solution Inductively Coupled Plasma Mass Spectrometry (SO-ICPMS) among three groups: control fish (artificially-reared), treatment (deep-hooked) and wild fish. The multivariate Redundancy Analysis fitted to test the general chemical composition of the otoliths among groups revealed a significant chemical signature of hooking characterized by an increase in Sr and Co, and in a smaller effect Ca. Moreover, we found otolith microchemistry as a useful method to differentiate between artificially-reared and wild mulloway. Positive results across other taxa and different recreational and commercial fisheries should show the real magnitude of the chemical signals of hook ingestion, its utilization as a biological tag and its consequences for the health of released individuals.

Stock management should be guided by assessment models that, among others, need to be fed by reliable data of catch and effort. However, precise data are difficult to obtain in heterogeneous fisheries. Specifically, small-scale, multi-gear, multispecies fisheries are dynamic systems where fishers may lively change fishing strategy (i.e., métier) conditioned by multiple drivers. Provided that some stocks can be shared by several métiers, a precise categorization of métiers should be the first step toward métier-specific estimates of catch and effort, which in turn would allow a better understanding of the system dynamics. Here we propose an approach for predicting the métier of any given fishing trip from its landing records. This approach combines the knowledge of expert fishers with the existing sales register of landings in Mallorca (Western Mediterranean). It successfully predicts métiers for all the 162,815 small-scale fishery fishing trips from Mallorca between 2004 and 2015. The largest effort is invested in the métiers Cuttlefish/Fish and Spiny lobster, landings peak for Cuttlefish/Fish and Dolphinfish and revenues for Spiny lobster and Dolphinfish. Métier predictions also allowed us to describe the temporal (seasonal and between-year) trends experienced by each métier and to characterize the species (commercial categories) that are specific to each métier. Seasonal variability is by far more relevant than between-year variability, which confirms that at least some fishers are adopting a rotation cycle of métiers along the year. Effort (fishing trips), landings and gross revenues decreased in the last 12 years (2004–2015). The approach proposed is also applicable to any other fishery for which the métier for a fishing trip sample is known (e.g., on-board observers or logbooks), but relying on fishers expertise points more directly to fishers’ intention. Thus, métier predictions produced with the proposed approach are closer to the actual uses of fishers, providing better grounds for an improved management., This work has received funding from the European Union’s Horizon 2020 Research and Innovation program under Grant Agreements 634495 (MINOUW) and 678193 (CERES).

An amalgam of empirical data from laboratory and field studies is needed to build robust, theoretical models of climate impacts that can provide science-based advice for sustainable management of fish and shellfish resources. Using a semi-systematic literature review, Gap Analysis and multilevel meta-analysis, we assessed the status of empirical knowledge on the direct effects of climate change on 37 high-value species targeted by European fisheries and aquaculture sectors operating in marine and freshwater regions. Knowledge on potential climate change-related drivers (single or combined) on several responses (vital rates) across four categories (exploitation sector, region, life stage, species), was considerably unbalanced as well as biased, including a low number of studies (a) examining the interaction of abiotic factors, (b) offering opportunities to assess local adaptation, (c) targeting lower-value species. The meta-analysis revealed that projected warming would increase mean growth rates in fish and mollusks and significantly elevate metabolic rates in fish. Decreased levels of dissolved oxygen depressed rates of growth and metabolism across coherent species groups (e.g., small pelagics, etc.) while expected declines in pH reduced growth in most species groups and increased mortality in bivalves. The meta-analytical results were influenced by the study design and moderators (e.g., life stage, season). Although meta-analytic tools have become increasingly popular, when performed on the limited available data, these analyses cannot grasp relevant population effects, even in species with a long history of study. We recommend actions to overcome these shortcomings and improve mechanistic (cause-and-effect) projections of climate impacts on fish and shellfish., Sí

The phenotypical variability in otolith shape of anchoveta (Engraulis ringens) was analysed in three zones (I, II and III) from north to south along the Chilean coast, using juvenile and adult fish. Generalised additive models were used to analyse shape indices and canonical discriminant analysis was used to analyse elliptical Fourier harmonics. The form factor and ellipticity indices varied significantly among the three zones, whereas roundness, circularity and rectangularity indices only showed differences between Zones I and III. Fourier reconstructed outlines for five ontogenetic stages suggested important differences among sampling zones, which were larger for sampling Zone III, where, at the same fish length, otoliths were smaller than those sampled in Zones I and II, at least at the pre-recruit stage. Elliptical Fourier descriptors showed significant differences among the three units, with a total percentage of correct classifications for juveniles of 89 and 74% for raw data and cross-validated cases respectively, compared with >85 and ∼65% respectively for adult fish. The results support the hypothesis that juveniles and adults of anchoveta have remained segregated throughout their entire, or at least a fraction of, their life cycle, mainly between the extreme northward and southward zones., The sampling for this study was performed as part of the hydroacousti recruitment survey of anchoveta and the Spawning Monitoring Project, funded by the Chilean Ministry of Economy, Promotion and Tourism (Asesoría Integral en Pesca y Acuicultura, ASIPA, grants 2015 and 2016). Morphological analyses were funded by the Chilean Fund for Fisheries and Aquaculture Research (Fondo de Investigación Pesquera y Acuícola, FIPA, grant 2015–22).

Escape incidents of farmed fish involve economic losses to fish farms, interactions with local fisheries and environmental impacts to coastal ecosystems. In order to ensure a sustainable aquaculture activity it is advisable to gather any kind of information about the escapees for further management strategies. In this study, we aimed to trace the life history of escaped meagre (Argyrosomus regius) through otoliths microchemistry, based on the assumption that escaped fish experience different environmental conditions once they are outside the net-pen compared to their farmed conspecifics. Strontium (Sr88) and barium (Ba138) composition was analyzed using laser-ablation ICP-MS along core-to-edge transects of right sagittal otoliths on escaped and farmed meagre from the same coastal area in the W-Mediterranean Sea. Overall, results showed similar patterns of Sr concentrations throughout the otolith transects between farmed and escaped meagre, although some differences can be observed at specific periods of fish life for Ba concentrations. Consequently, temporal variations regarding otolith Sr:Ba ratios differed between farmed and escaped meagre, suggesting that farmed and escaped fish shared the same origin (rearing at coastal farms) but inhabited in different conditions from a certain time of their life. However, core-to-edge Sr:Ba values also differed among escaped individuals, which might indicate that each individual escaped in different periods. Consequently, the otolith Sr:Ba ratio seemed to be a good indicator of differences between fish groups, showing different temporal patterns. Nevertheless, the limitation of the low number of sampled individuals prevented to draw clearer conclusions. Further research is necessary in order to investigate the potential use of otolith microchemistry as a practical tool to trace of escaped fish, and consequently, to help solving potential conflicts among coastal users improving management of potential negative socioeconomic and ecological impacts., This work was partially supported by the “Adapting to the wild: assessing meagre otoliths escaped from culture cages and evaluation of possible risks in Mediterranean ecosystems” funded by the Department of Education, Culture and Sport of the Valencian Community, Spain (GV/2015/107). SPM's salary was cofunded by the DGPUR of the Balearic Government and CSIC. This study received Portuguese national funds from FCT - Foundation for Science and Technology through project UIDB/04326/2020.