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There are three different species of redfish (Sebastes spp.) in the waters of the Flemish Cap (Division 3M, NAFO Regulatory Area): S. fasciatus, S. mentella, and S. norvegicus. Historically, S. fasciatus and S. mentella have been managed together as a single stock because of similar biology and difficulty in species identification. Here we use multivariate autoregressive state-space models to examine the abundance trajectories of the three species and to determine whether they can be treated as a single stock for management purposes or whether they should be treaty separately. We also included covariates to evaluate relationships with climate, commercial catch, and the abundance of predators and (or) competitors and prey. We did two separate analyses: (i) a single-period analysis over the full time series and (ii) a blocked, two-period analysis over different regulatory periods. In both analyses, the best-fit model included separate trajectories for each species at each depth but one overall stock growth rate; both also included commercial catches as a covariate. These analyses suggest that a single assessment for the Sebastes complex is acceptable., Sí

17 pages, 2 figures, 3 tables, supporting information https://doi.org/10.1111/mms.12945, Identifiable food remains were analyzed from 46 stomachs of striped dolphins (Stenella coeruleoalba) stranded in southern Spain between 2007 and 2014. Results suggest that the species feeds mainly on mesopelagic and neritic fish, but also on oceanic squids. Fish species of the family Myctophidae were the main prey in terms of numerical importance and reconstructed prey weight (62% N and 29% W), followed by squids of the family Ommastrephidae (20% W) and bogue (Boops boops) (15% W). The most important prey taxa according to the General Importance Index (GII) were C. maderensis, Ommastrephidae gen. spp., Notoscopelus spp., and M. punctatum. Higher number of mesopelagic myctophids were found in dolphins from the Mediterranean (73% vs. 29% N), while more demersal gobiids and European hake (Merluccius merluccius) were found in those from the Atlantic (44% vs. 1% and 8% vs., This work was carried out in the Oceanographic Centre of Vigo (Spanish Institute of Oceanography of the Spanish National Research Council; IEO-CSIC) partially funded by the Spanish Ministry of Economy and Competitiveness Demographic Challenge (MITECO) through the Commission [28-5307] for “Technical Scientific Advice for the Protection of the Marine Environment: Assessment and Monitoring of Marine Strategies, Monitoring of Marine Protected Areas of State Competence (2018–2021).” M.G.P., carried out this work while registered with the “Campus do Mar doctorate program.” J.G. was supported by the Spanish National Program “Juan de la Cierva-Formación” (FJC2019-040016-I). The contribution of J.G. and R.D.S. was partially supported by the EcoCet Project from the MITECO [CGL2011-25543] and the “Fundación Biodiversidad”, through the FEMP, Pleamar programme. [...] This work acknowledges the “Severo Ochoa Centre of Excellence” accreditation (CEX2019-000928-S) to the Institute of Marine Science (ICM-CSIC)

Dinoflagellates are a group of protists whose exceptionally large genome is organized in permanently condensed nucleosome-less chromosomes. In this study, we examined the potential role of repetitive DNAs in both the structure of dinoflagellate chromosomes and the architecture of the dinoflagellate nucleus. Non-denaturing fluorescent in situ hybridization (ND-FSH) was used to determine the abundance and physical distribution of telomeric DNA and 16 microsatellites (1- to 4-bp repeats) in the nucleus of Gambierdiscus australes. The results showed an increased relative abundance of the different microsatellite motifs with increasing GC content. Two ND-FISH probes, (A)20 and (AAT)5, did not yield signals whereas the remainder revealed a dispersed but nonrandom distribution of the microsatellites, mostly in clusters. The bean-shaped interphase nucleus of G. australes contained a region with a high density of trinucleotides. This nuclear compartment was located between the nucleolar organizer region (NOR), located on the concave side of the nucleus, and the convex side. Telomeric DNA was grouped in multiple foci and distributed in two polarized compartments: one associated with the NOR and the other peripherally located along the convex side of the nucleus. Changes in the position of the telomeres during cell division evidenced their dynamic distribution and thus that of the chromosomes during dinomitosis. These insights into the spatial organization of microsatellites and telomeres and thus into the nuclear architecture of G. australes will open up new lines of research into the structure and function of the nucleosome-less chromatin of dinoflagellates., Deteccion innovadora de proliferaciones algales toxicas: una necesidad frente al calentamiento global, SI

14 pages, 10 figures, 2 tables, 1 appendix, [EN] Marine protected areas (MPAs) are a promising management tool for the conservation and recovery of marine ecosystems, as well as fishery management. MPAs are generally established as permanent closures but marine systems are dynamic, which has generated debate in favour of more dynamic designs. As a consequence, the identification of priority areas should assess their persistence in space and time. Here, we develop a step-by-step approach to assess the spatiotemporal dynamics of fishery management priority areas using standard fishery-independent survey data. To do so, we fit Bayesian hierarchical spatiotemporal SDM (species distribution model) models to different commercially important demersal species and use the resulting maps to fit different spatial prioritisation configurations. The proposed method is illustrated through a western Mediterranean case study using fishery-independent trawl survey data on six commercially important species collected over 17 years. We use these results to assess the spatiotemporal dynamics of fishery priority areas. We identified two fishery priority area patterns in the study area, each predominant during a different time period of the study, asserting the importance of regularly reassessing MPA designs, [FR] Les aires marines protégées (AMP) constituent un outil de gestion prometteur pour la conservation et le rétablissement des écosystèmes marins, ainsi que pour la gestion des pêches. Si les AMP sont généralement établies comme zones interdites à la pêche permanentes, le caractère dynamique des systèmes marins est à l’origine d’arguments en faveur d’une conception plus dynamique de ces aires. La délimitation de secteurs prioritaires devrait ainsi comprendre une évaluation de leur persistance dans l’espace et le temps. Nous présentons une approche par étape pour évaluer la dynamique spatiotemporelle de secteurs prioritaires pour la gestion des pêches qui fait appel à des données d’évaluation indépendantes des pêches standards. Pour ce faire, nous ajustons des modèles de répartition d’espèces (MRE) spatiotemporels hiérarchiques bayésiens à différentes espèces démersales d’importance commerciale et utilisons les cartes ainsi produites pour ajuster différentes configurations de priorisation spatiale. La méthode proposée est illustrée par une étude de cas de l’ouest de la mer Méditerranée qui fait appel à des données de relevés au chalut indépendantes de la pèche pour six espèces d’importance commerciale, recueillies sur 17 années. Nous utilisons ces résultats pour évaluer la dynamique spatiotemporelle de secteurs prioritaires pour la pêche. Nous cernons deux motifs de secteurs prioritaires pour la pêche dans la région d’étude, chacun étant prédominant durant différentes périodes de l’étude, ce qui souligne l’importance d réévaluer régulièrement la conception des AMP, MEDITS project has been co-funded since 1994 by the EU through the European Maritime and Fisheries Fund (EMFF) within the National Program of collection, management and use of data in the fishery sector and support for scientific advice regarding the Common Fisheries Policy. IP would like to thank the Fundación Biodiversidad (Spanish Ministry of Agriculture and the Environment) for the funding provided and the invaluable help provided to access the required data. DC and ALQ also thank the Spanish Ministerio de Ciencia e Innovación—Agencia Estatal de Investigación for grant PID2019-106341GB-I00 (jointly financed by the European Regional Development Fund, FEDER). MGP also thanks the IMPRESS (RTI2018-099868-B-I00) project, ERDF, Ministry of Science, Innovation and Universities—State Research Agency. JG was supported by the Spanish National Program Juan de la Cierva-Formación (FJC2019-040016-I). This work acknowledges the “Severo Ochoa Centre of Excellence” accreditation (CEX2019-000928-S) to the Institute of Marine Science (ICM-CSIC)

Harmful Algal Blooms (HAB) pose a severe socio-economic problem worldwide. The dinoflagellate species Alexandrium catenella produces potent neurotoxins called saxitoxins (STXs) and its blooms are associated with the human intoxication named Paralytic Shellfish Poisoning (PSP). Knowing where and how these blooms originate is crucial to predict blooms. Most studies in the Chilean Patagonia, were focused on coastal areas, considering that blooms from the adjacent oceanic region are almost non-existent. Using a combination of field studies and modelling approaches, we first evaluated the role of the continental shelf off northern Chilean Patagonia as a source of A. catenella resting cysts, which may act as inoculum for their toxic coastal blooms. This area is characterized by a seasonal upwelling system with positive Ekman pumping during spring-summer, and by the presence of six major submarine canyons. We found out that these submarine canyons increase the vertical advection of bottom waters, and thus, significantly enhance the process of coastal upwelling. This is a previously unreported factor, among those involved in bloom initiation. This finding put this offshore area at high risk of resuspension of resting cysts of A. catenella. Here, we discuss in detail the physical processes promoting this resuspension., DETECCIÓN INNOVADORA DE PROLIFERACIONES ALGALES TÓXICAS: UNA NECESIDAD FRENTE AL CALENTAMIENTO GLOBAL, DIANAS, SI

The reproductive success of aquatic animals depends on a complex web of relationships between the environment, the attributes of the reproductive individuals and human-induced selection. All of them are manifested directly or indirectly through parental effects, which can also compensate for certain external impacts. Parental effects refer to the influence that the phenotype and environmental conditions in which individuals develop exert on the phenotype of their offspring, and they can even have transgenerational impact. This paper describes the different types of parental effects and reviews the published literature to analyze the causes of their variation and their impact on reproductive resilience and population dynamics., SI

Anthropogenic litter is considered a potential vector for the dispersal of non-indigenous species (NIS) in marine ecosystems. Using the bay of Gijon (Southwestern Bay of Biscay) as a case study, we studied the composition and potential transfer of the communities inhabiting three different environment components: 1) natural and artificial substrates from the international port of Gijon, 2) six proximate rocky beaches and 3) floating litter collected in the adjacent coast. A total of 717 organisms were morphologically identified and DNA barcoded using COI and 18S genes. In total 23 NIS were detected, six of them considered invasive in the area. The taxonomic profiles of the three environment components were significantly different, flotsam containing higher proportions of Hexanauplia and less mollusks, echinoderms and polychaetes than ports and beaches. Contrary to expectations, floating litter showed higher densities of native and exotic species than beaches or port surfaces. This and shared haplotypes between port, flotsam and beaches in some invasive species may indicate that marine litter could represent a new habitat for species to disperse into new areas., SI

15 pages, 6 figures, 2 tables.-- This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY), Flemish Cap cod collapsed in the early 90’s after facing multiple threats due to climate variability and anthropogenic pressures. A master 35-year cod growth chronology was reconstructed in the present study by using sclerochronology techniques. Three additional chronologies were developed to account for the age-dependent effect of maturity and fishing intensity on growth. All chronologies showed that cod growth has decreased over the years and it is currently at the minimum level in the historic of data series. Hierarchical mixed-effects models were applied to the master chronology to identify extrinsic drivers of growth. The master chronology was divided into 3 periods: Premoratorium (1988-1998), Moratorium (1999-2009), and Postmoratorium (2010-2019). Our results showed that drivers of cod growth in the Flemish Cap varied between periods (Premoratorium: bottom temperature and fishing mortality, Moratorium: cod and pandalus abundance, and Postmoratorium: cod abundance and thickness of the cold intermediate layer). Our results suggest that density-dependence processes, food availability, and global warming may be behind the lack of recovery of the Flemish Cap cod stock. The Flemish Cap cod growth chronology shows variations on growth over time and identifies its drivers, having the potential to be included in the NAFO stock assessments or to be used to set dynamic reference points that guarantees the stock sustainability, The samples analyzed in this study were collected during the Flemish Cap survey that are co-funded by the European Union through the European Maritime and Fisheries Fund (EMFF) within the National Program of collection, management and use of data in the fisheries sector and support for scientific advice regarding the Common Fisheries Policy

Fishery data is one of the most accessible sources of information currently used for ecological studies and stock assessments. Unlike scientific surveys that are usually restricted to a given time of the year, fisheries dependent data is almost continuously available in time. Moreover, the information collected from the fisheries is less expensive and time consuming. However, for use as a relative abundance index, fishery-dependent data requires standardization as catch-per-unit-effort (CPUE) in order to remove the impact of vessel-specific differences and fishing behavior. Understanding the key factors that influence the population dynamics of fish species implies assessment of their spatial distribution and seasonal habitat selection but, spatio-temporal dependence issues are often not explicitly included in the modeling process. This study standardizes sardine fishery-dependent data obtained from the west coast of Portugal as CPUE by means of a Bayesian hierarchical spatio-temporal model using integrated nested Laplace approximation (INLA). This is one of the first studies of the region to provide maps of the relative abundance of this species for all months of the year. The best model included length of the vessel, vessel ID, month, year and location (latitude, longitude), while none of the five environmental covariates (Chl-a, SST, bathymetry, current velocity and direction) were relevant. In terms of spatial distribution, sardines were more abundant in the northern area, especially during the last quarter of the year. The applied methodology has contributed to improve our knowledge of European sardine distribution throughout the year, providing accurate predictive maps and insights into the standardization process of fishery-dependent data that could also be applied to other fish species and areas., Improving scientific advice to fishery managenent for resources of interest for Spain in Atlantic waters, IMPRESS, FCT (PTDC/MAT-STA/ 28243/2017), SARDINHA2020 (PO Mar2020, MAR-01.04.02- FEAMP- 0009)

SI

15 pages, 4 figures, 7 tables, Length-based methods have been widely applied to estimate biological parameters and understand the dynamics of marine resource populations within data-limited stocks. However, to date few studies have tested the sensitivity of parameters in length-based methods examining stocks with different traits and fishery contexts. In the Bay of Biscay and the Iberian Coast ecoregion, SE Europe (International Council for the Exploration of the Sea - ICES, Divisions 8 and 9a), many commercial resources are considered data-limited, and either little is known about their fisheries stock statuses or gaps remain in currently available assessments. Therefore, this study focuses on two of the most used length-based methods, which ICES considers to be the most appropriate to evaluate data-limited stocks, namely length-based indicators (LBI) and the length-based spawning potential ratio (LBSPR). Both methods have been applied to assess the stock statuses of various relevant species in the study area, such as: the small-spotted catshark (Scyliorhinus canicula), European anchovy (Engraulis encrasicolus), blackspot seabream (Pagellus bogaraveo), pouting (Trisopterus luscus), pollack (Pollachius pollachius), and Norway lobster (Nephrops norvegicus). For each stock, model results were compared with available knowledge on their current status. Furthermore, this paper discusses whether unexpected results are related to violations of the main model assumptions (constant total mortality and recruitment, and logistic selectivity) or to a lack of representativeness of stock length composition. A sensitivity analysis was conducted on the two most important input parameters: L∞ (von Bertalanffy asymptotic average maximum body size) and M/k (ratio of natural mortality to von Bertalanffy growth rate). This analysis concluded that the variation/misspecification of both parameters (M/k and L∞) had a considerable impact on the results given by both methods, and that this effect is more significant in the case of the L∞ parameter, thus highlighting the importance of its accuracy in a given assessment. Furthermore, the sensitivity analysis indicated that, among the LBI and LBSPR indicators, the least robust indicator was the LBI Pmega indicator. The remaining LBI method indicators can be considered more robust than the LBSPR indicators when there is uncertainty in the life history input parameters (M/k and L∞). Among LBSPR indicators, SPR is more affected than F/M (relative fishing mortality) by the variation/misspecification of parameter L∞, whereas under the variation of M/k both indicators perform similarly. However, it is important to consider that LBI indicators are very rough measures of stock statuses, whereas LBSPR measures describe stock statuses more explicitly. Thus, both measures can be used together to obtain more precision in estimating stock status. Nevertheless, when critical parameters are uncertain (e.g., L∞) and the results of both methods contradict one another, LBI method indicators, with the exception of Pmega, are more trustworthy than LBSPR indicator, This study is a contribution to the IMPRESS project (RTI2018–099868-B-I00), ERDF, Ministry of Science, Innovation and Universities - State Research Agency and also of GAIN (Xunta de Galicia), GRC MERVEX (nº IN607-A 2018–4)

The common sole (Solea solea) is a species of flatfish of great commercial relevance in the northern Atlantic Iberian waters. Although many studies investigated the early life-stage of this species, little is known on the adult phases and the size structure of the population. Here we provide an analysis of the spatiotemporal distribution of adult’s common sole occurrence, conditional-to-presence biomass and median length in northern Atlantic Iberian waters using a Bayesian approach and three different spatiotemporal model structures that characterize the fundamental distributional patterns of fish as either persistent, opportunistic or progressive. Results highlight that the distribution of common sole adults in the area has been persistent over the years and that is partially affect by the bathymetry. Three main abundance hotspots were identified coinciding with spatial closure areas restricted to the fishing activity. Additionally, results show that small specimens tend to aggregate in shallower waters, while larger specimens inhabit deeper waters. Understanding the spatiotemporal distribution of the common sole population could improve our knowledge of this species and help to design more accurate biomass index that could be used to calibrate stock assessment models., SI

Harmful algal blooms (HABs) cause harm to human health or hinder sustainable use of the marine environment in Blue Economy sectors. HABs are temporally and spatially variable and hence their mitigation is closely linked to effective early warning. The European Union (EU) Interreg Atlantic Area project “PRIMROSE”, Predicting Risk and Impact of Harmful Events on the Aquaculture Sector, was focused on the joint development of HAB early warning systems in different regions along the European Atlantic Area. Advancement of the existing HAB forecasting systems requires development of forecasting tools, improvements in data flow and processing, but also additional data inputs to assess the distribution of HAB species, especially in areas away from national monitoring stations, usually located near aquaculture sites. In this contribution, we review different novel technologies for acquiring HAB data and report on the experience gained in several novel local data collection exercises performed during the project. Demonstrations include the deployment of autonomous imaging flow cytometry (IFC) sensors near two aquaculture areas: a mooring in the Daoulas estuary in the Bay of Brest and pumping from a bay in the Shetland Islands to an inland IFC; and several drone deployments, both of Unmanned Aerial Vehicles (UAV) and of Autonomous Surface vehicles (ASVs). Additionally, we have reviewed sampling approaches potentially relevant for HAB early warning including protocols for opportunistic water sampling by coastguard agencies. Experiences in the determination of marine biotoxins in non-traditional vectors and how they could complement standard routine HAB monitoring are also considered., SI

The link between the dynamic organization of the ovary and spawning dynamics was investigated in pelagic fishes with indeterminate fecundity. Αn array of laboratory methods and statistical approaches was applied to samples of gonadal material from three commercial NE Atlantic fish species: the sardine, Sardina pilchardus, the horse mackerel, Trachurus trachurus, and the mackerel, Scomber scombrus. Methods included the application of clustering analysis algorithms in histological specimens and the application of particle analysis on whole mounts. More specifically, various attributes of ovarian dynamics such as the oocyte size frequency distribution, the ratio of total to batch fecundity, the number of oocyte cohorts, and the recruitment of early secondary growth oocytes were related to historic estimates of spawning interval and oocyte growth rate. It was shown that indeterminate spawners can display varying proportions of oocytes at the size range between primary and secondary growth based on the seasonal pattern of oocyte recruitment. This finding indicates that determinacy and indeterminacy should rather be recognized as end-points along a continuum which is controlled by the degree of overlap between oocyte recruitment period and spawning period. It was also demonstrated that fishes like sardine with long spawning intervals and fast oocyte growth exhibit relatively few, clearly separated oocyte cohorts, while fishes like mackerel with shorter spawning interval display increased number of coexisting cohorts. Ultimately, these aspects may provide a proxy of spawning interval and thereby spawning frequency which is a variable of paramount importance in biomass assessments of commercial fish stocks through egg production methods., SI

13 pages, 8 figures, 2 tables, In the Iberian Coast region, the common sole (Solea solea) is considered a very relevant species due to its high commercial value. Despite its importance, the current status of this stock is still poorly known due to the scarcity of available data to apply formal assessment methods. In data-poor situations length-based methods have been widely applied to estimate biological parameters and to understand the dynamics of marine stocks. In this study we evaluate the status of common sole in the Iberian Coast region using the following three different length-based methods: (1) the length-based indicators, (2) the length-based spawning potential ratio and (3) the mean length-based mortality estimators. Overall, the three methods agree that this stock appears to be exploited at the maximum sustainable yield level, the immatures are well preserved whereas the proportion of large mature individuals is relatively low, although it has been increased in the last years. Assessing the status of this valuable stock through data-limited methods is the first step towards designing and implementing effective management measures, This study is a contribution to the project IMPRESS (RTI2018-099868-B-I00), ERDF, Ministry of Science, Innovation and Universities - State Research Agency and also of GAIN (Xunta de Galicia), GRC MERVEX (nº IN607-A 2018-4)

A new species of the marine dinophyte genus Heterocapsa Stein is described. Two clonal strains originating from Argentinean coastal waters were examined with light and electron microscopy and LSU and ITS rDNA sequence data were obtained. Heterocapsa claromecoensis sp. nov. is described as a distinctive species with a conical epitheca, a similar sized and rounded hypotheca, a single reticulate chloroplast situated in the periphery of the cell, and a large pyrenoid in the episome, above an ellipsoidal to rounded nucleus in the hyposome. The plate tabulation pattern of Po (pore plate), cp (cover plate), X (X-plate or canal plate), 5ꞌ, 3a, 7ꞌꞌ, 6c, 5s, 5ꞌꞌꞌ, 2ꞌꞌꞌꞌ was as for most other species of Heterocapsa. H. claromecoensis sp. nov. differs from all other species of Heterocapsa by the microarchitecture of two different types of organic body scales, which uniquely were different in height. Phylogenetic trees based on LSU and ITS rDNA sequences placed H. claromecoensis in a separate branch, with a sequence assigned to H. orientalis being the closest match based on LSU rDNA., Sí

Identifying the mechanisms controlling the temporal dynamics of ecological communities is key to understand their vulnerability to natural and anthropogenic impacts and to identify early warnings of critical transitions. At community level, inter-specific synchrony is an important indicator of ecosystem stability and variation in function. Using wavelet analysis on time-series of abundance of 12 dominant diatom species, sampled monthly (1994-2009) in a coastal upwelling embayment at the northern limit of the Canary Current Upwelling System, we find a sudden onset of synchrony between 1998 and 2002, concomitant with an increase in the amplitude of the upwelling index at different temporal scales. To better understand the underlying mechanism that could generate this sudden onset of synchrony among competitors, we analyzed a general model of competition between two species for two essential nutrients (e.g., nitrogen and silicate). We incorporate environmental variation by varying the concentration of one of the essential nutrients entering the system. Increase in the amplitude of environmental variation always leads to greater synchrony among competitors. This occurs because the system shifts from a state in which species are limited by different nutrients to one where species are often limited by the same nutrient. We show that the transition from asynchronous to synchronous dynamics can occur suddenly as the amplitude of environmental variation increases. While it is not possible to rule out alternative mechanisms, our model demonstrates that sudden changes in the extent of synchronization should be a common feature when species compete for essential nutrients in variable environments., SI

8 pages, 5 figures, 2 tables, supplementary data https://doi.org/10.1016/j.marenvres.2022.105702, Although there is a great knowledge about individual anthropogenic threats to different fish species in the Mediterranean Sea, little is known about how these threats accumulate and interact to affect fish species richness in conjunction with environmental dynamics. This study assesses the role of these threats in the fish richness component and identifies the main areas where the interaction between fish species richness and threats is highest. Our results show that fish richness seems to be higher in saltier and colder areas where the chlorophyll-a and phosphate concentrations are lower. Among the anthropogenic threats analyzed, the costal impact and the fishing effort seems to be the more relevant ones. Overall areas with high fish richness are mainly located along the western and northern shores, with lower values in the south-eastern regions. Areas of potential high cumulative threats are widespread in both the western and eastern basins, with fewer areas located in the south-eastern region. By describing the spatial patterns of the fish richness and which drivers explain these patterns we can also identify which anthropogenic activities can be managed more effectively to maintain and restore marine fish biodiversity in the basin, MGP to the project IMPRESS (RTI2018-099868-B-I00), ERDF, Ministry of Science, Innovation and Universities - State Research Agency. MC acknowledges partial funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 869300 (FutureMares project) and the Spanish project ProOceans (Ministerio de Ciencia e Innovación, Proyectos de I + D + I (RETOS-PID2020-118097RB-I00). MC acknowledges the institutional support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S). D.C. would like to thank the Spanish Ministerio de Ciencia e Innovación - Agencia Estatal de Investigación for grant PID2019-106341 GB-I00 (jointly financed by the European Regional Development Fund, FEDER). J.M.-M. would like to thank the Ministry of Science, Innovation and Universities for PID2020-115882RB-I00 research project

16 pages, 5 figures, supplementary material https://doi.org/10.3354/meps14125, Small pelagic fish (SPF) species such as European sardine Sardina pilchardus, European anchovy Engraulis encrasicolus, round sardinella Sardinella aurita and European sprat Sprattus sprattus play important ecological roles in the Mediterranean Sea marine ecosystem. However, changes in SPF abundance and biomass have recently been observed in the basin. Therefore, uncovering the trophic importance of SPF to their predators is key to unravelling potential ecological causes and consequences of SPF population changes related to predator dynamics. Here, we reviewed 101 published studies reporting the presence of the SPF species named above in the diet of marine predators inhabiting the Mediterranean Sea. We found that the number of species preying on SPF was highest for teleost fish species, followed by elasmobranchs, seabirds, marine mammals, cephalopods and sea turtles. These predators were both commercial and non-commercial taxa, and vulnerability ranged from medium to very high. From a conservation point of view, most predator species were considered Least Concern by the IUCN, with few exceptions such as the Balearic shearwater Puffinus mauretanicus, a Critically Endangered species. Geographic information showed that the European sardine was more important in the diet of predators from the western Mediterranean basin, while European anchovy consumption was higher on the eastern side. Round sardinella was consumed in high amounts in the Tyrrhenian Sea, and European sprat was anecdotally consumed. The importance of SPF in the diet of Mediterranean predators may indicate bottom-up control of the marine ecosystem; however, limited temporal information precluded the evaluation of temporal changes, highlighting the need to develop new studies in this area, This study was carried out within the Spanish Research project PELWEB (CTM2017-88939-R) funded by Spanish Ministry of Science, Innovation and Universities and the European Research Contract SPELMED (EASME/EMFF/2016/032) funded by ECEASME. J.OC. was supported by Universitat de Barcelona through the PREDOCS- UB grant (2021). J.G. was supported by the Spanish National Program Juan de la Cierva-Formación (FJC2019-040016-I). J.N. was supported by the Spanish National Program Ramon y Cajal (RYC-2015-17809). M.G.P. thanks the project IMPRESS (RTI2018-099868-B-I00), ERDF, Ministry of Science, Innovation and Universities—State Research Agency and also of GAIN (Xunta de Galicia), GRC MER VEX (no. IN607-A 2018-4). E.FC. was funded by the Spanish Ministry of Universities (FPU predoctoral research grant no. 05523). We acknowledge the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S) to the Institute of Marine Science (ICM-CSIC)

13 pages, 7 figures, 1 table, supplementary data https://doi.org/10.1093/icesjms/fsac077.-- Data availability statement: The questionnaire data are available at https://github.com/Jrehren/ICES-2021-Rehren-Evaluating-impacts-of-fishing-gear-regulations. The other data underlying this article will be shared on reasonable request to the corresponding author, Ecosystem models, such as Ecopath with Ecosim (EwE), are useful tools for developing ecosystem-based management strategies. Model development, however, requires data for the estimation of input parameters including time series for calibration. Most small-scale fisheries lack such information, making it difficult to reliably use ecosystem models for management strategy exploration. This is the case for the Chwaka Bay fishery (Zanzibar), where an increase in dragnets has led to concerns for unsustainable development. While EwE could help to explore the impacts of gear regulations in the bay, this is hampered by the lack of time series to estimate the predator–prey interactions (vulnerabilities) in the model. Here, we explore available approaches for estimating the vulnerabilities to simulate the effects of a dragnet prohibition with and without reallocation of fishing effort. Simulations suggest that banning dragnets would be beneficial for the fishing community judged by the increase in biomass of functional groups and fishers’ profits, but not if dragnet fishers were to continue fishing in the bay by reallocating to other gears, indicated by the reduced fish biomass and fishers’ profits. The overall trend (decreasing or increasing) in the changes of functional groups, ecosystem indicators, and profits were relatively consistent across vulnerability settings, illustrating that an unfitted EwE model can be used for qualitative management strategy exploration, This project was funded by the German Research Foundation (DFG) within a research fellowship programme (RE 4358/1–1). The data used in the analysis were collected in 2014 within a PhD programme (SUTAS) funded by the Leibniz Gemeinschaft. The questionnaires on fishers' perception of historical fisheries catches were conducted within the National Geographical Society Early Career Grant, #EC-67901C-20. MC acknowledges funding support by the European Union's Horizon 2020 research and innovation programme under grant agreement No 869300 (FutureMares). VC acknowledges support from the Natural Sciences and Engineering Research Council of Canada (NSERC), Discovery Grant RGPIN-2019–04901. This work acknowledges the “Severo Ochoa Centre of Excellence” accreditation (CEX2019-000928-S) to the Institute of Marine Science (ICM-CSIC)

8 pages, 3 figures, 2 tables, supplementary data https://doi.org/10.1016/j.seares.2022.102170, Cetacean strandings represent unique opportunities to collect biological material from these wild animals and obtain information on their population statuses. Here, we apply biological and pathological perspectives to analyze stranded cetaceans collected along the Sardinian coast (Italy) between 2006 and 2011. We quali-quantitatively explore the primary causes of deaths, and use Bayesian Hierarchical Models (BHMs) to explore the potential effects of cetacean sex, age, body length, and month, year, and stranding location on Dicloro Difenil Tricloroetano (DDT) and Polychlorinated Biphenyl (PCB) contaminant loads. Although natural causes, such as bacterial and virus infections, were identified to be the main causes of death among the stranded cetaceans, fisheries also played an important role among the anthropogenic causes of death. The BHMs revealed that both contaminants were positively related to the length, sex and age of the cetaceans, and that higher concentrations of these contaminants were mainly found in larger and older individuals. Despite the scattered nature of these data, the present study contributes valuable insights into the major causes of death of stranded cetaceans, and adds to growing worldwide efforts to biomonitor cetaceans, This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. J.G. was supported by the Spanish National Program ‘Juan de la Cierva-Formación’ (FJC2019-040016-I). This study acknowledges the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S) to the Institute of Marine Science (ICM-CSIC)

15 pages, 2 tables, 7 figures.-- This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY), The dinoflagellate genus Prorocentrum includes several harmful toxigenic species, predominantly benthic ones. In the past, fast-acting toxicity in mice has been observed in extracts of the epibenthic species P. borbonicum, with the finding of two compounds termed as borbotoxins-A and -B. The presence of palytoxin-like compounds was also suggested from electrophysiological experiments. In the present study, a strain of P. borbonicum was isolated in the continental coast of Colombian Caribbean, in seagrass beds of Thalassia testudinum in Bonito Gordo, Tayrona National Natural Park (PNNT). The morphological and molecular characteristics were consistent with the original and former descriptions for this species. Typical haemolytic activity due to palytoxin was confirmed in P. borbonicum extracts in presence of ouabain, the toxin contents being estimated as 1.9 pg palytoxin equivalents cell-1. HPLC-HRMS analyses of these extracts unambiguously identified the presence of borbotoxins and 42-hidroxy-palytoxin (42-OH-PLTX). This is the first report of palytoxin-like compounds in another dinoflagellate genus than Ostreopsis and the first record of P. borbonicum in Colombia and the Caribbean region, This work was funded by the following entities: the Ministry of Science, Technology and Innovation of Colombia - MINCIENCIAS (COLCIENCIAS), the Marine and Coastal Research Institute “Jose Benito Vives de Andreis” (INVEMAR, Contribution number: 1340) and Environmental and Sustainable Development Ministry (MINAMBIENTE) through BPIN project, the International Atomic Energy Agency (IAEA) through the Research Contract RC#18827 (“Bentox Project”) and the Technical Cooperation projects RLA/7/014 and RLA/7/020, the Spanish national project CCVIEO (CNIEO-CSIC), with additional funds of the Axencia Galega de Innovación (agreement GAIN-IEO), la Universidad Nacional de Colombia-UNAL Sede Caribe (within the Project “Influencia de recursos y reguladores en la abundancia de dinoflagelados bentónicos del Caribe”, Hermes Code: 40410). EA-S was supported by a COLCIENCIAS grant (call No. 727–2015)

In February 2019, seamounts of the Discovery Rise, SE Atlantic (41–45°S, 3°W - 3°E), were explored in support of the application of the Ecosystem Approach to Fisheries Management in the Southeast Atlantic Fisheries Organization (SEAFO) Convention Area. Video records of the seafloor were produced by the Video-Assisted Multisampler System (VAMS) along 15 valid transects conducted in plateau and flank areas of Shannon, Tablemount, Discovery and Heardman seamounts at depths ranging from 394 to 1839 m. Nine benthic seascapes were classified and described based on substrate hardness, texture, slope, physical and biological modifiers as observed in the video images. Predominant water masses were estimated from temperature, salinity and dissolved oxygen vertical profiles obtained by CTD casts in the vicinity of each transect. A total of 366 fishes were seen (total observation time = 25.0 h) and classified in 32 morphotypes, included in 9 orders and 12 families. Most fish morphotypes (14) were included in the Macrouridae family. Family Moridae, on the other hand, included 65.3% of all fish records (239), with two particularly abundant morphotypes: Laemonema sp. (116) and Guttigadus sp. (92). Thirteen cephalopods were observed and classified in five morphotypes; the oegopsid squid Moroteuthopsis ingens was the most abundant of them (6). Despite the taxonomic uncertainties associated with video identifications, the explored region was found to contain a mixture of tropical – subtropical and subantarctic faunas of the Atlantic. Similarities of fauna composition and non-directional beta diversity estimates revealed some degree of seamount identity, but 57.5–61.9% of morphotypes were shared among seamounts (Jaccard = 0.425, Sørensen = 0.381). Fishes and cephalopods were more frequently observed on the shallower plateau areas under the influence of warmer and more oxygenated Antarctic Intermediate Waters. Depth and related factors did not influence richness, but dissimilarities in fauna composition between video transects increased with increasing depth intervals. Spatial habitat heterogeneity may have accounted for the increased beta diversity within seamounts. The most widely explored Tablemount seamount contained the most diverse observed sites, but also a considerable spatial variability likely associated with seascape heterogeneity. In two sites (transects 11 and 14), there were exceptionally high aggregations of the morid cods Laemonema sp., at the shallowest ‘gravely’ site explored (397 m), and Guttigadus sp., at a site of intermediate depth (1020 m) covered mostly by soft sediments. Neither of these species (or congenerics) have been previously classified as ‘seamount-aggregating” species. On the other hand, the Patagonian toothfish (Dissostichus eleginoides) and other commercial species known to aggregate in these seamounts were not found in the explored areas., SI

13 pages, 5 figures, 2 tables, supplementary material https://doi.org/10.1016/j.pocean.2022.102745, Small pelagic fish (SPF) are key organisms for the functioning of pelagic marine ecosystems. In recent decades, these species have undergone significant changes in biomass, growth and body condition in the Mediterranean Sea. Seasonal and spatial information about changes in biological and ecological traits of SPF and their relationship with environmental variables is still missing. Here, we have investigated along a latitudinal gradient in the Northwestern Mediterranean Sea the seasonal patterns of fish fitness (in terms of body condition, fat content and reproduction activity) of two important Mediterranean SPF, European anchovy (Engraulis encrasicolus) and European sardine (Sardina pilchardus). We used non-parametric multivariate analyses and Generalized Additive Models (GAMs) to investigate which environmental and trophic variables could explain observed variations during 2018–2019. Mean fat content values, relative condition index (Kn) and gonadosomatic index (GSI) were calculated monthly. We also measured individual’s stable isotope composition in muscle. Chlorophyll-a, sea surface temperature and salinity were used as environmental descriptors. The results revealed spatial and temporal variations for both species in terms of body condition, fat content and reproduction indices, as well as of stable isotopic values. GAMs showed that the variability in fitness for both species was mostly explained by environmental variables, in addition to the spatial and seasonal factors. Trophic variables contributed to explain the variability of the indices, mostly in the case of anchovy. This study provides insights into the spatial and seasonal interplay of the fitness of two important commercial species along a latitudinal gradient, and contributes to understand the fluctuations of SPF population and recent declining trends to inform proactive fisheries management at local and regional scale, E.L.-L. was supported by a FPU grant (FPU1704395, Spanish Ministry of Education associated). J.G. and J.N. were supported by the Spanish National Program Juan de la Cierva-Formación (FJC2019-040016-I) and Ramon y Cajal (RYC-2015-17809), respectively. This study is a contribution to the project PELWEB (CTM2017-88939-R, Ministry of Science and Innovation, Spain) and PELCAT (CAT 152CAT00013, TAIS ARP059/19/00005). [...] This work acknowledges the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S) to the Institute of Marine Science (ICM-CSIC)

12 pages, 7 figures, 3 tables, Fish-killing blooms of Heterosigma akashiwo and Pseudochattonella verruculosa have been devastating for the farmed salmon industry, but in Southern Chile the conditions that promote the growth and toxicity of these microalgae are poorly understood. This study examined the effects of different combinations of temperature (12, 15, 18 °C) and salinity (10, 20, 30 psu) on the growth of Chilean strains of these two species. The results showed that the optimal growth conditions for H. akashiwo and P. verruculosa differed, with a maximum rate of 0.99 day−1 obtained at 15 °C and a salinity of 20 psu for H. akashiwo, and a maximum rate of 1.06 day−1 obtained at 18 °C and a salinity of 30 psu for P. verruculosa. Cytotoxic assays (2 × 101 – 2 × 105 cell mL−1; cells, filtrates, and cell lysates) performed at salinities of 20 and 30 psu showed a 100% reduction in the viability of embryonic fish cells exposed to intact cells of H. akashiwo and a 39% reduction following exposure to culture filtrates of P. verruculosa. Differences in the fish-killing mechanisms (direct cell contact vs. extracellular substances) and physiological traits of H. akashiwo and P. verruculosa explain the recent occurrence of very large blooms under contrasting (cold-brackish vs. hot-salty) extreme climate conditions in Chile, This study was funded by project REDI170575 (Patricio A. Díaz) from the International Cooperation Programme of the National Agency for Research and Development (ANID), Chile. Dr. Carlos Molinet was funded by the FONDAP Project N° 15110027 (INCAR)

20 pages, 7 tables, 5 figures.-- This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY), Shorewatch is a citizen science project, managed by Whale and Dolphin Conservation (WDC), that records the occurrence of cetaceans during regular, standardized watches from a series of locations along the coast of Scotland (United Kingdom). Observer training and a clearly defined protocol help deliver a valuable source of information about cetacean occurrence and activity along the coast. Between 2005–2018, over 52000 watches generated over 11000 sightings of at least 18 cetacean species. Generalized Additive Models based on sightings for the five most commonly sighted species (bottlenose dolphin, harbor porpoise, minke whale, Risso’s dolphin, and common dolphin), at those sites with the longest time series, demonstrated seasonal, geographical and year-to-year differences in their local occurrence and relative abundance. Bottlenose dolphins are mainly present at observation sites located on the east coast of Scotland, being uncommon on the west coast, while harbor porpoise and minke whale are principally present at sites located on the west coast. The seasonality observed in cetacean occurrence is consistent with peak abundance in summer months described by previous studies in the area. Mean depth around the observation sites is the static variable that apparently has the greatest influence on species presence and number of sightings, except for Risso’s dolphin. All the species except bottlenose dolphin showed upward trends in occurrence and number of sightings over the period 2012–2018. Evidence of temporal autocorrelation was found between results from consecutive watches at the same site on the same day as well as between results from consecutive days at the same site. The power to detect declines in local abundance over a 6-year period depends on the underlying sighting rate of each cetacean species, the number of watches performed and the rate of decline. Simulations performed to determine the power to detect a decline suggest that the current intensity of observation effort in some observation sites, of about 2500 watches per year, may offer good prospects of detecting a 30% decline of the most frequently sighted species (95% of the time) over a 6-year period, although a more even distribution of observation effort in space and time is desirable. The data could potentially be used for monitoring and 6-yearly reporting of the status of cetacean populations., This work was funded by Whale and Dolphin Conservation (WDC) and NatureScot (formerly Scottish Natural Heritage)

17 pages, 10 figures, 1 table.-- Open Access under Creative Commons by Attribution Licence, Organic carbon mineralization and nutrient cycling in benthic environments are critically important for their biogeochemical functioning, but are poorly understood in coastal upwelling systems. The main objective of this study was to determine benthic oxygen fluxes in a muddy sediment in the Ria de Vigo (NW Iberian coastal upwelling), by applying the aquatic eddy covariance (AEC) technique during 2 campaigns in different seasons (June and October 2017). The main drivers of benthic fluxes were studied and compared among days in each season and between seasons. The 2 campaigns were characterized by an upwelling-relaxation period followed by a downwelling event, the last of which was due to the extratropical cyclone Ophelia in October. The mean (±SD) seasonal benthic oxygen fluxes were not significantly different for the 2 campaigns despite differences in hydrodynamic and biogeochemical conditions (June: −20.9 ± 7.1 mmol m−2 d−1 vs. October: −26.5 ± 3.1 mmol m−2 d−1). Benthic fluxes were controlled by different drivers depending on the season. June was characterized by sinking labile organic material, which enhanced benthic fluxes in the downwelling event, whereas October had a significantly higher bottom velocity that stimulated the benthic fluxes. Finally, a comparison with a large benthic chamber (0.50 m2) was made during October. Despite methodological differences between AEC and chamber measurements, concurrent fluxes agreed within an acceptable margin (AEC:benthic chamber ratio = 0.78 ± 0.13; mean ± SD). Bottle incubations of water sampled from the chamber interior indicated that mineralization could explain this difference. These results show the importance of using non-invasive techniques such as AEC to resolve benthic flux dynamics, M.A.S. and N.V.R. were funded by the Spanish Government through a Formación de Profesorado Universitario fellowship (FPU 18/05051) and a Juan de la Cierva-Formación fellowship (FJCI-2017−34290), respectively. Financial support was provided by the Spanish Ministry of Science and Innovation through the i-SMALL project (CTM2014-56119-R) and by the European Union FEDER project MarRISK (0262_MarRISK_1_E). This study was also supported by grants from the US National Science Foundation (OCE-1550822, OCE-1824144) and the University of Virginia

Competitive interactions between marine mammals and fisheries represent some of the most complex challenges in marine resource management worldwide. The development of commercial fisheries and recovering marine mammal populations have contributed to a decrease in fish availability. Whilst ecosystem-based fisheries management (EBFM) can counteract this decrease, achieving the EBFM objectives faces certain major obstacles including insufficient or unreliable data, inapplicable assessment models, as well as inadequate management decisions that do not account for fisheries-induced morphological alterations (FIMA) and marine mammal management. Despite a body of evidence addressing various aspects of marine mammal−fisheries competition, little is known about the effects of marine mammal−fisheries biological interactions affecting the fish viability and food web stability. We review the research on marine mammal− fisheries competitive biological interactions (hereafter biological competition) by focussing on (1) the prerequisites for marine mammal−fisheries biological competition and the relevant metho - dologies to explore them and (2) recent studies revealing the implications of FIMA and trophic interactions for the biological competition. We also discuss the implications of FIMA, eco-evolu- tionary feedback and prey−predator dynamics for EBFM implementation in contemporary har- vested ecosystems. Our main findings reveal a lack of data about marine mammals’ prey choice and selectivity, the need for better representation of marine mammals in modelling approaches and lastly, the necessity for additional research linking FIMA, trophic interactions and the EBFM objectives. To conclude, interdisciplinary approaches may serve to link all of the efforts needed to effectively and holistically support the implementation of EBFM., SI

A new warm-water benthic dinoflagellate species, Coolia guanchica sp. nov., is described from the Canary Islands (NE Atlantic Ocean), a subtropical archipelago with a rich benthic biodiversity. Samples of benthic microalgae were collected at Tenerife, and three strains of a previously unreported ribotype of the genus Coolia were found. Identification was carried out by combining morphological (light microscope, LM; and scanning electron microscope, SEM) and molecular (large subunit ribosomal gene, LSU rRNA; and internal transcribed spacer region, ITS1-5.8S-ITS2 rRNA) data from clonal cultures. Phylogenetic analyses revealed that the new strains formed a well-supported clade, sister to Coolia canariensis. The genetic distance of more than 0.20 for LSU and 0.30 for the ITS region (uncorrected p values) from the closest members of the genus (C. canariensis and C. cf. canariensis) showed species-level divergence to justify the description of a new species, Coolia guanchica sp. nov. A bioassay with Artemia salina was used to check the toxicity of the species, with negative results. Coolia guanchica has rounded cells, with plate 4′ as the largest plate of the epitheca and plate 6′′ about twice as wide as long, similar to C. canariensis and C. areolata. It differs morphologically from the other two ribotypes in the C. canariensis complex in having a lighter hypothecal ornamentation, larger thecal plate pores scattered randomly throughout the cell and higher pore density per thecal plate., Sí

Brittle stars constitute a common and highly diverse component of epibenthic communities, and they can form dense aggregations on the seabed of all oceans worldwide. Nevertheless, there is limited information on the diversity and distribution of these echinoderms in Northwest Africa. Between 2004 and 2012, 10 multidisciplinary Spanish and Norwegian surveys were conducted off Northwest Africa—between the Strait of Gibraltar and Sierra Leone border—from a depth of 19 to 1888 m. During these surveys, we sampled 1298 stations, and about one million individuals and 124 kg of brittle stars were collected from 502 stations. Forty-two species belonging to eight ophiuroid families considered as suspension feeders were collected from 296 stations and represented 93.4% of the total abundance and 75% of the total ophiuroid-specific richness. Ophiacanthidae was the richest and most abundant family, with 15 species and estimated densities up to almost 4 × 10⁵ by 0.1 square kilometre. The other families found abundantly were Amphiuridae, Ophiotrichidae and Ophiactidae, represented by six, five and four species each, respectively. Ophiotrichidae, Ophiacanthidae and Gorgonocephalidae presented the largest biomass among the suspension-feeder families (35.5%, 33.8% and 28.2%, respectively), and Ophiotrichidae is a well-represented family along the Northwest African coast. The most remarkable concentrations and highest diversity values were detected on the upper slope (depth, 400–600 m) off Western Sahara. Between 24°N and 22°N, we collected huge concentrations of Ophiacantha abyssicola and up to six species per station. This area has permanent and intense upwelling conditions and is out of the minimum oxygen zone. We also noted significant densities and richness at Cape Ghir and Cape Blanc, where important filaments of nutrient-rich waters occur, and at Guinea-Bissau, which is affected by nutrient river inputs. The multivariate analysis clearly separated the brittle stars into two main assemblages, across latitudinal and bathymetrical gradients: northern latitude (Morocco and Northern Sahara) from the area south of 24°N and from the continental shelf–upper slope to the deep slope., Sí

Sardine fisheries in the Iberian Atlantic shelf (36°N–44.5°N) show decadal-scale cycles. In the late 1990s, a positive phase in sardine stock was expected; on the contrary, catches have declined until now. Regime shifts in climatic and oceanographic variables on different scales (as forcing factor) and shifts in sardine stock (as result) have been used with the aim of identifying the physical variables that explain most of the sardine population variance in the region. Circa 1998, when last sardine regime shift was detected, the main patterns of large-scale atmospheric circulation in the Northern Hemisphere with influence in the study area namely Northern Atlantic Oscillation (NAO) and East Atlantic (EA) pattern changed and coupled in a combination that led to a rise in sea surface temperature and a decline in the coastal upwelling intensity. Several years with a downwelling situation in average in the main spawning and feeding Iberian sardine areas would have affected the stock abundance, averting the return to the projected positive regime. The sardine negative regime shift was detected first in the regions of the study located further north. The regional variable latent heat flux that groups a set of environmental processes related to the ocean–atmosphere heat exchanges and so with the turbulence manages to explain the 72% of sardine recruitment., Sí

Dinoflagellates in the genus Gambierdiscus are known to produce potent neurotoxins known as ciguatoxins. These toxins vector through the food web and can reach sufficiently high levels to cause ciguatera fish poisoning (CFP). In many regions of the Caribbean, little is known about the occurrence of CFP-causing species or the incidence of CFP, despite its apparent regional increase over the last few decades. Given the intraspecific variability in content and potencies of these toxins among Gambierdiscus species, the precise identification of local species of this genus is crucial. In this study we confirm the presence of the epibenthic dinoflagellate Gambierdiscus caribaeus in the Colombian continental Caribbean. Cells were collected in seagrass beds of Thalassia testudinum in Bonito Gordo, a site located on the western side of Bahía Concha, Tayrona National Natural Park, near the city of Santa Marta, Colombia. Subsequently, a single strain of Gambierdiscus could be established for further identification. Morphological (light and scanning electron microscopy), and molecular results (partial LSU and ITS rDNA sequencing) were consistent with the original description of G. caribaeus, as well as with the morphological characteristics shown by other authors in organisms obtained near the sampling area., SI

As industrialized fishing activities have moved into deeper water, the recognition of Vulnerable Marine Ecosystems (VMEs) has become important for the protection of the deep-sea. Our limited knowledge on the past and present distribution of VMEs hinders our ability to manage bottom fisheries effectively. This study investigated whether accounting for bottom fishing intensity (derived from Vessel Monitoring System records) as a predictor in habitat suitability models can (1) improve predictions of, and (2) provide estimates for a pre-fishing baseline for the distribution and biomass of a VME indicator taxon. Random Forest models were applied to presence/absence and biomass of Geodia sponges and environmental variables with and without bottom fishing intensity. The models including fishing were further used to predict distribution and biomass of Geodia to a pre-fishing scenario. Inclusion of fishing pressure as a predictive term significantly improved model performance for both sponge presence and biomass. This study has demonstrated a way to produce a more accurate picture of the current distribution of VMEs in the study area. The pre-fishing scenario predictions also identified areas of suitable Geodia habitat that are currently impacted by fishing, suggesting that sponge habitat and biomass have been impacted by bottom trawling activities., SI

Microplastics (, SI

The growth pattern and parameters of Atlantic chub mackerel in Northern Iberian waters were analysed for the first time in this study, using otolith analyses (direct age estimation-DAE, back-calculation-BC and otolith marginal analyses) and length frequency analyses (Bhattacharya, SLCA and PROJMAT methods), on a time series of data from 2011 to 2017. Two main different growth patterns were obtained, one slower (DAE, BC and PROJMAT) and other faster (Bhattacharya and SLCA). Otolith marginal analyses showed an annual periodicity in the formation of one hyaline and one opaque edge, with a prevalence of the opaque edge from June to December, what in addition to the unimodal distribution of the annuli radii and the obtained back-calculated mean lengths, similar to those obtained by DAE, support the age estimation criteria used here. The growth parameters obtained from DAE (L∞: 45.34, k: 0.28, t0: -1.18) are proposed for the upcoming stock assessment process., SI

15 pages, 6 figures, 3 tables, Organophosphate flame retardants (OPFRs) are (re-)emergent environmental pollutants increasingly being used because of the restriction of other flame retardants. The chlorinated OPFR, tris(1,3-dichloro-2-propyl) phosphate (TDCPP) is among those of highest environmental concern, but its potential effects in the marine environment have rarely been investigated. We exposed a widely used sentinel marine mussel species, Mytilus galloprovincialis, to 10 μg L−1 of TDCPP during 28 days and studied: (i) the kinetics of bioaccumulation and elimination of the compound, (ii) the effect on two molecular biomarkers, glutathione S-transferase (GST) and acetylcholinesterase (AChE) activities, and (iii) proteomic alterations in the gills, following an isobaric labeling quantitative shotgun proteomic approach, at two exposure times (7 and 28 days). Uptake and elimination of TDCPP by mussels were very fast, and the bioconcentration factor of this compound in mussels was 147 L kgww-1, confirming that this compound is not very bioaccumulative, as predicted by its chemical properties. GST activity was not affected by TDCPP exposure, but AChE activity was inhibited by TDCPP at both 7 and 28 days of exposure. Proteomic analysis revealed subtle effects of TDCPP in mussel gills, since few proteins (less than 2 % of the analysed proteome) were significantly affected by TDCPP, and effect sizes were low. The most relevant effects detected were the up-regulation of epimerase family protein SDR39U1, an enzyme that could be involved in detoxification processes, at both exposure times, and the down-regulation of receptor-type tyrosine-protein phosphatase N2-like (PTPRN2) after 7 days of exposure, which is involved in neurotransmitter secretion and might be related to the neurotoxicity described for this compound. Exposure time rather than TDCPP exposure was the most important driver of protein abundance changes, with 33 % of the proteome being affected by this factor, suggesting that stress caused by laboratory conditions could be an important confounding factor that needs to be controlled in similar ecotoxicology studies. Proteomic data are available via ProteomeXchange with identifier PXD019720, L.E. F.-G. is supported with a predoctoral fellowship from Xunta de Galicia (Consellería de Cultura, Educación e Ordenación Universitaria grant ED481A-2017/298) partially co-founded by operative program FSE Galicia 2014-2020. M.C. is supported by the Ramón y Cajal contract (Ministry of Science and Innovation of Spain). This study was funded by Xunta de Galicia (refs. ED431C 2017/36, ED431C 2017/46, ED431C 2020/05 and IN607B 2018/10) and the Spanish Agencia Estatal de Investigación (refs. CTM2017-84763-C3-R-2 and CTM2016-77945-C3), partially co-funded by the European Regional Development Fund (FEDER/ERDF)

Microplastics are gaining worldwide attention due to their omnipresence. The marine environment is one of the most affected systems; especially the sediment compartment. Microplastic separation from the sediment matrix is the first step to evaluate its abundance and availability. Nevertheless, a lack of consistency in extraction protocols is a fact. This paper describes the optimization of the microplastic extraction procedure from marine sediments. The Plackett-Burman saturated factorial design was used to identify the significant factors and to select optimum working conditions. With this purpose, the following variables were studied: the number of extractions; the amount of sediment; the settling time; the density separation solution volume; the agitation time and the suitability of using wet or freeze-dried sediment. The Plackett-Burman design has revealed that the most statistically significant variables were sediment mass and agitation time. The optimized method was applied for two marine sediments collected in the Mar Menor Lagoon., Sí

Coastal areas are environments of high diversity and severely threatened by hazards as marine litter and biological invasions. Citizens’ knowledge and awareness are drivers of changes needed to improve environment conservation. Density both of litter and IAS Cortaderia selloana were measured from six beaches in southwest Bay of Biscay along with awareness of inhabitants of the zone using a social survey. Relationship between beach littering, alien invasion and perception and awareness of adults and students were assessed. Litter levels were associated with port presence and showed relationship between environmental degradation, IAS and litter accumulation. Adults were more aware about both issues and their perception of litter and plant invasion were positively correlated. Results suggest enhancing marine awareness, with more effort addressed specifically to students. There is a misperception of the real magnitude of IAS and litter impacts that should be approached improving awareness about this topics in the younger generations., SI

Chromosomal markers of the diversity and evolution of dinoflagellates are scarce because the genomes of these organisms are unique among eukaryotes in terms of their base composition and chromosomal structure. Similarly, a lack of appropriate tools has hindered studies of the chromosomal localization of 5S ribosomal DNA (rDNA) in the nucleosome-less chromosomes of dinoflagellates. In this study, we isolated and cloned 5S rDNA sequences from various toxin-producing species of the genus Alexandrium and developed a fluorescence in situ hybridization (FISH) probe that allows their chromosomal localization. Our results can be summarized as follows: 1) The 5S rDNA unit is composed of a highly conserved 122-bp coding region and an intergenic spacer (IGS), the length and sequence of which are variable even within strains. 2) Three different IGS types, one containing the U6 small nuclear RNA (snRNA) gene, were found among four of the studied species (A. minutum, A. tamarense, A. catenella and A. pacificum). 3) In all strains investigated by FISH (A. minutum, A. tamarense, A. pacificum, A. catenella, A. andersonii and A. ostenfeldii), 5S rDNA gene arrays were separate from the nucleolar organizer region, which contains the genes for the large 45S pre-ribosomal RNA. 4) One to three 5S rDNA sites per haploid genome were detected, depending on the strains/species. Intraspecific variability in the number of 5S rDNA sites was determined among strains of A. minutum and A. pacificum. 5) 5S rDNA is a useful chromosomal marker of mitosis progression and can be employed to differentiate vegetative (haploid) vs. planozygotes (diploid) cells. Thus, the FISH probe (oligo-Dino5Smix5) developed in this study facilitates analyses of the diversity, cell cycle and life stages of the genus Alexandrium., DIANAS, DETECCIÓN INNOVADORA DE PROLIFERACIONES ALGALES TÓXICAS: UNA NECESIDAD FRENTE AL CALENTAMIENTO GLOBAL, SI

8 pages, 2 tables, A recently published study analyzed the phylogenetic relationship between the genera Centrodinium and Alexandrium, confirming an earlier publication showing the genus Alexandrium as paraphyletic. This most recent manuscript retained the genus Alexandrium, introduced a new genus Episemicolon, resurrected two genera, Gessnerium and Protogonyaulax, and stated that: “The polyphyly [sic] of Alexandrium is solved with the split into four genera”. However, these reintroduced taxa were not based on monophyletic groups. Therefore this work, if accepted, would result in replacing a single paraphyletic taxon with several non-monophyletic ones. The morphological data presented for genus characterization also do not convincingly support taxa delimitations. The combination of weak molecular phylogenetics and the lack of diagnostic traits (i.e., autapomorphies) render the applicability of the concept of limited use. The proposal to split the genus Alexandrium on the basis of our current knowledge is rejected herein. The aim here is not to present an alternative analysis and revision, but to maintain Alexandrium. A better constructed and more phylogenetically accurate revision can and should wait until more complete evidence becomes available and there is a strong reason to revise the genus Alexandrium. The reasons are explained in detail by a review of the available molecular and morphological data for species of the genera Alexandrium and Centrodinium. In addition, cyst morphology and chemotaxonomy are discussed, and the need for integrative taxonomy is highlighted, Support to DMA from the NOAA ECOHAB program (Grant #NA15NOS4780181) is gratefully acknowledged. Support to EG, AR, NS from the COPAs project (CTM2017-86121-R) is acknowledged. IGL and CJBS are COFFA-IPN and EDI-IPN fellows, With the funding support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S), of the Spanish Research Agency (AEI)

Some benthic dinoflagellates produce toxins that can affect other organisms including humans, and their proliferation seems to be related to the environmental variability. For this reason, the present study aims to compare the structural variation of potentially toxic dinoflagellates associated with the seagrass Thalassia testudinum from two nearby systems, with different environmental characteristics in Colombian Caribbean, corresponding to a brackish water coastal lagoon and an adjacent bay. Between January 2014 and December 2015, leaves of T. testudinum were collected monthly to obtain the dinoflagellates. Salinity, temperature, dissolved oxygen, pH, nutrients and total suspended solids (TSS) were measured, and precipitation data and the Oceanic Niño Index (ONI) were obtained. Dinoflagellates were detached from the leaves, morphologically identified by analyzing their thecal plates arrangements, and quantified using a Sedgewick-Rafter chamber. The information was analyzed using standard statistics and regression models. Fourteen species of potentially toxic epiphytic dinoflagellate belonging to four genera were recorded, being Prorocentrum the most representative in number of species. The maximum density, dominated by P. lima, were found in Bahía Chengue during the rainy season of 2014 (18452 and 20109 cells g−1 w.w.), with salinity of 35.50, high temperatures (>29.60 °C), dissolved oxygen >6 mg L−1, pH close to 8 and TSS >85 mg L−1. Densities at the Lagoon were lower than 80 cells g−1 w.w. with the highest values of Prorocentrum sp.1 under different environmental conditions. With the statistical relationships between the most abundant species and the main environmental variables, fundamental niche models were proposed in which cells could proliferate. The degree of risk to human health due to the presence of these potentially toxic epiphytic dinoflagellates will not be resolved until their toxicity discarded., Sí

Seabed litter of the Flemish Pass area (NW Atlantic Ocean) was analysed and described using data from the EU-Spain groundfish survey (2006-2017 period). This study presents baseline information on seabed litter in this area. The Flemish Pass is located in areas beyond national jurisdiction within the Northwest Atlantic Fisheries Organization Regulatory Area Division 3L. A total of 1169 valid bottom trawl hauls were analysed (104-1478 m depth). Litter was found in 8.3% of the hauls, with mean densities of 1.4±0.2 items km–2 and 10.6±5.2 kg km–2. An increasing pattern with depth was found, the highest densities of seabed litter being identified in the deepest areas located in the Flemish Pass channel and down the northeastern flank of the Grand Bank. Fishing was found to be the main source of marine litter, and 61.9% of the hauls with litter presence showed litter included in the fisheries-related litter category. Whereas in most cases the litter was composed of small fragments of rope, in other cases it was composed of entire fishing gears such as traps. Plastics, metal and other anthropogenic litter were the next most abundant categories, accounting for 18.6%, 16.5% and 12.4% of the total, respectively., La basura en los fondos marinos del área de Flemish Pass (Océano Atlántico Noroeste) ha sido analizada y descrita utilizando datos de las campañas demersales de EU-España (período 2006-2017). Este estudio presenta información de referencia sobre la basura en los fondos marinos de esta área. Flemish Pass está localizado en áreas más allá de las jurisdicciones nacionales dentro del Área Reguladora de la Organización para las Pesquerías del Atlántico Noroccidental División 3L. Se han analizado un total de 1169 lances de arrastre de fondo válidos (104-1478 m de profundidad). Se ha encontrado basura en el 8.3% de los lances con densidades medias de 1.4±0.2 ítems km–2 y 10.6±5.2 kg km–2. Se ha hallado un patrón de aumento con la profundidad, identificándose densidades mayores de basura marina en las áreas más profundas ubicadas en el canal Flemish Pass y en el flanco noreste del Gran Banco. Se ha descubierto que la pesca es la principal fuente de basura marina, el 61.9% de los lances con presencia de basura mostraron desechos incluidos en la categoría de basura relacionada con la actividad pesquera. Mientras que en la mayoría de los casos la basura estaba compuesta por pequeños fragmentos de cabo, en otros casos estaba compuesta por aparejos como nasas. Posteriormente, los plásticos, el metal y otros desechos antropogénicos fueron las categorías más abundantes, con 18.6%, 16.5% y 12.4%, respectivamente.

The MARTEC18 Conference “International Conference on advances in marine technologies applied to discard mitigation and management” was held from May 2nd to 5th, 2018 in Vigo. MARTEC18 welcomed 118 attendees and 48 worldwide speakers from 17 Research Centers, Universities, 3 Business Companies and representatives from FAO, regional, national and European administration. After the conference, MARTEC18 Steering Committee offered participants to submit their works as research papers in a Special Issue. This Marine Policy Special Issue “Advances in marine technologies applied to discard mitigation and management” gathers 16 peer-reviewed research papers which summarize main outcomes on discard mitigation research as well as show the state-of-the-art both in reducing unwanted catch and increasing by-catch utilization, MARTEC18 was funded by the LIFE iSEAS project ‘Knowledge-Based Innovative Solutions to Enhance Adding-Value Mechanisms towards Healthy and Sustainable EU Fisheries’ (LIFE13 ENV/ES/000131) as a part of its dissemination activities

Plastic debris is found in nearly all marine regions and is a known threat to marine biota. This study evaluates the ingestion of plastic marine debris (macro and micro plastics) by a piscivorous predator, Alepisaurus ferox Lowe (1833). A total of 27 specimens were captured in 2015 and 2016 in the North Atlantic (around 34 degrees-36 degrees N and 10 degrees-16 degrees W) and their stomachs were dissected and inspected for plastic elements. Macroplastic particles were found in 37% of fish, with an average weight of 0.46 +/- 1.14 g with film being the most abundant category (60%). The main polymers characterized were Polypropylene (PP) and Polyethylene (PE). Microplastics were found in 74% of the stomachs, with item values per individual ranging from 0 to 16, with an average value of 4.7 +/- 4.8 items per stomach. Only microfibers and fragments were observed, with microfibers (similar to 85 %) being the dominant type, SI

10 pages, 13 figures, 2 tables, Monitoring plays a key role in all aspects of fisheries management, including those related to sustainable management of resources, the economic performance of the fishery, and the distribution of benefits from the exploitation of the fishery and environment. In this manuscript, an electronic device (the iObserver) is described, which aims to improve fisheries monitoring by identifying and quantifying fishing catches on board commercial vessels. This device is located over the conveyor belt in the fishing sorting area to automatically take pictures of the entire catch during fish separation. Each picture is analyzed using open source image recognition software to identify the number of individuals, the species and length of each individual based on skin descriptors (color, texture), and shape. The iObserver is equipped with a graphical and user-friendly interface. The information provided by the iObserver is sent to the RedBox software, where it is aggregated and augmented with vessel instrumentation data, such as location, velocity, and course. Then, the data are sent to a shore-based center to be used for different purposes, including the following: feeding mathematical models describing stock evolution; identifying those regions with a large presence of individuals below a Minimum Conservation Reference Size (MCRS); and supporting administrative decisions about a given fishing region, The authors acknowledge funding received from the EU LIFE+program (Project LIFE iSEAS–LIFE13 ENV/ES/000131)

The objective of this review is to summarize information on microfibers in seawater and sediments from available scientific information. Microfibers were found in all reviewed documents. An heterogeneous approach is observed, with regard to sampling methodologies and units. Microfibers in sediments range from 1.4 to 40 items per 50 mL or 13.15 to 39.48 items per 250 g dry weight. In the case of water, microfibers values ranges from 0 to 450 items·m− 3 or from 503 to 459,681 items·km− 2. Blue is the most common color in seawater and sediments, followed by transparent and black in the case of seawater, and black and colorful in sediments. Related with polymer type, polypropylene is the most common in water and sediments, followed by polyethylene in water and polyester in water and sediments. Some polymers were described only in water samples: high-density polyethylene, low-density polyethylene and cellophane, whilst only rayon was reported in sediments., Sí

Benthic dinoflagellates of the genus Gambierdiscus produce ciguatoxins, compounds that when metabolized in fish and consumed by humans cause ciguatera poisoning (CP). This syndrome, which is widespread in tropical and subtropical regions, has recently been reported also in subtropical-temperate latitudes such as the Canary Islands where CP events have been regularly detected since 2004. This study examined the effect of temperature on the growth of Gambierdiscus isolated from Canary waters: G. australes, G. caribaeus, G. carolinianus, G. excentricus, and G. silvae. From the temperature vs. growth curves, the maximum growth (µm), optimum temperature range for growth (Topt), and the temperature yielding maximum growth (Tm) were estimated for each species. The results revealed temperature-dependent differences in the growth parameters. G. caribaeus had the highest Tm and Topt, followed by G. australes, G. carolinianus, G. silvae, and G excentricus. G. australes tolerated the widest range of temperatures (from 15 ◦C to 29 ◦C), which may explain its broader geographic distribution, both worldwide and across the Canary archipelago. Neither G. excentricus nor G. silvae survived at 29 ◦C whereas G. caribaeus reached mean growth rates (± standard deviation) up to 0.19 ± 0.01 div.day− 1 at that temperature, followed by G. australes (0.16 ± 0.01 div.day− 1) and G. carolinianus (0.14 ± 0.04 div.day− 1). G. caribaeus showed no measurable growth at 19◦C, whereas G. excentricus and G. silvae along with G. australes appeared as the species better adapted to lower temperatures. In an intraspecific variability study of 12 strains of G. australes, the mean (± standard deviation) of µm and Tm were 0.17 ± 0.01 div.day− 1 and 27.7 ± 0.5 ◦C, respectively. An analysis of the shapes and position of the cell nuclei at the different temperatures showed that nuclei characteristic of vegetative cells appeared mainly at 26 ◦C but extreme temperatures resulted in nuclei with a more variable morphology. The presence of putative zygotes at extreme temperatures (17 ◦C, 19 ◦C and 29 ◦C) suggests that sexual reproduction is promoted as an adaptive strategy which could play an important role in the expansion of geographic distribution of Gambierdiscus species., SI

Few studies have mined social media platforms to assess environmental concerns. In this study, Twitter was scraped to obtain a ~140,000 tweet dataset related specifically to marine plastic pollution. The goal is to understand what kind of users profiles are tweeting and how and when they do it. In addition, topic modelling and graph theory techniques have allowed us to identify main concerns on this topic: i) impact on wildlife, ii) microplastics/water pollution, iii) estimates/reports, iv) legislation/protection, and v) recycling/cleaning initiatives. Results reveal a scarce influence of organizations involved in research and marine environmental awareness, so some guidelines are depicted that could help to adjust their communication plans. This is relevant to engage society through reliable information, change habits and reinforce sustainable behaviour. A visualization tool has been created to analyze the results over time., La lucha contra la basura marina en el Espacio Atlántico, This work was co-financed by both the European Regional Development Fund through the CleanAtlantic INTERREG (Atlantic Area) project [grant number EAPA_046/2016] and the Agencia Estatal de Investigación (Ministerio de Ciencia e Innovación, Government of Spain) through ANDROMEDA project [grant number PCI2020-112047]., CLEANATLANTIC, ANDROMEDA, SI

13 pages, 2 tables, 3 figures, Gaidropsarus Rafinesque, 1810 is a genus of marine fishes, commonly known as rocklings, comprising 14 living species and showing a high ecological diversity from the intertidal zone to the deep sea. The systematics of this group has been controversial due to a general lack of representative specimens and the conservative morphology exhibited. A multidisciplinary approach combining the analysis of meristic data and the DNA barcode standard was applied in a species delimitation approach. Individuals representing eight valid and three unnamed species were collected, morphologically identified and archived in several museum collections. Comparison of DNA sequences shows complex results, furthering the idea of the difficult identification of specimens based on traditional taxonomy. DNA barcoding supports synonymies, like G. biscayensis–G. macrophthalmus and G. guttatus–G. mediterraneus, agreeing with the extensive overlaps observed in the meristic variables analysed and suggesting a reduction in the number of species. Genetic distances showed pairs of closely related species like G. granti–G. vulgaris and G. argentatus–G. ensis, the latter being only distinguished by one main distinctive character. Four deep-water specimens, morphologically classified only to the genus level, constituted three independent taxa apart from the ones present in this study and with no barcode matches in the repository databases. They could represent new records for the North Atlantic or unknown species of this genus. The results obtained show that more studies will be necessary to solve the systematics of this branch of the Gadiformes, This work was funded through the research project ECOMARG 3, Ministry of Agriculture, Food and the Environment, Spain, and the EC LIFE 07/NAT/E/000732+ ‘Nature Biodiversity’ INDEMARES project. Oceanographic surveys were partially funded by the EU through the European Maritime and Fisheries Fund within the National Programme of data collection in the fisheries sector.

9 pages, 5 figures, 3 tables, The autodiametric method is a highly streamlined method for estimating fecundity of fish with determinate oocyte development pattern. Greenland halibut presents a peculiar reproductive strategy with two simultaneously cohorts one of large vitellogenic oocytes (for the current year) and another one of small vitellogenic oocytes (for the subsequent year). Results of this study showed that autodiametric method can be applied to estimate fecundity in Greenland halibut. Additionally, spatial differences in the autodiametric calibration curve were observed in the Northwest Atlantic, but did not translate into differences in fecundity at length. This is the first time that spatial differences between ACCs of the same species have been reported, what could be the result of (i) the unusual oocyte development pattern, or (ii) spatial differences in oocyte biochemistry. More research on the relative dynamics of oocyte cohorts simultaneously present in Greenland halibut ovaries and the factors (endo- or exogenous) influencing oocyte packing density could provide a better understanding of observed geographical differences, This work was funded by the Spanish and Canadian Governments within the Action of the Canadian-Spanish Cooperation Program “Analysis of Stock Reproductive Potential to promote sustainability of Greenland Halibut fishery” (ACI2008-0754)