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En las últimas décadas, se viene registrando en el Atlántico noreste un cada vez mayor número de citas de especies ictiológicas de aguas cálidas más meridionales. Diversos trabajos relacionan este fenómeno con el aumento de la temperatura de las costas europeas como consecuencia del calentamiento global. En este contexto, se documenta para el mar Cantábrico la primera cita de un ejemplar de góbido del género Zebrus de distribución principalmente mediterránea y con tan solo unas pocas citas en el océano Atlántico. ABSTRACT: In recent decades, an increasing number of records of ichthyological species from more southern warm waters have been recorded in the northeast Atlantic. Several studies relate this phenomenon to the increase in the temperature of European coasts as a consequence of global warming. In this context, here we document the first record for the Cantabrian sea of a specimen of a gobid fish belonging to Zebrus genus, which typically exhibit a Mediterranean distribution with only a few records in the Atlantic Ocean.

Climate change is triggering shifts in species distribution eventually altering communities' biogeography. The composition of a community in terms of its species' ecological niche informs of a community's response to environmental conditions and impacts, which is central for a timely conservation. While the thermal niche has been widely explored, given it offers a direct link of warming effects on an assemblage, acknowledging the multivariate nature of a species niche can provide relevant insights of the reorganizations taking place at a community-level. We studied the mean and variance of 10 ecological traits at the community level in two regional ecosystems in the temperate East-Atlantic and the Mediterranean Sea, characterized by a distinct exposure to warming. Our findings revealed major temporal changes and spatial structuring in the traits and ranges explored over the last decades. Apart from confirming the expected general poleward, deep-ward shift, our results highlighted a widening of thermal and latitudinal ranges, possibly related to a ‘flexibilitation’ of the communities in a context of global change. In addition, temporal patterns reflected how communities have adjusted around regime shifts known in both areas. Regional differences arose concerning the variance of depth ranges and area of distribution, as well as to the global evolution of the communities, which we argue are consequence of their different geographical features and ecological history. The comparison of two large multitaxon assemblages has disclosed a broad-scale motion of response to warming in the bentho-demersal domain. We expect this study will contribute to the understanding of the multivariate nature of global-change effects on marine fauna, which ultimately informs adaptive management.

The assessment of the status of fisheries resources is pivotal due to the importance of marine resources in global food security and to halt the ongoing decline in marine biodiversity. Norway lobster (Nephrops norvegicus) is one of the most valuable resources in the Northeast Atlantic. However, overfishing has caused the decline of several Nephrops stocks over the last decades, particularly in the Nephrops Functional Units (FUs) 25 (NW Spain), 26-27 (NW Spain and North Portugal) and 31 (Cantabrian Sea, North Spain). Since 2003, the information provided by the very low level of landings and fishing effort of these three stocks was insufficient to carry out an adequate analytical assessment, so the base of the assessment has been the trends from commercial catch per unit effort (CPUE). The objective of this study was to carry out the first assessment of these three stocks with an analytical MSY-based model. A review of the available data was made and the stochastic Surplus Production Model in Continuous Time (SPiCT) was fitted for each FU. The results indicate an extremely low biomass for FUs 25 and 26-27 since the mid-nineties well below the reference points. For FU 31, on the other hand, estimated biomass is larger. Our findings also identified long-term temporal and spatial changes in the population dynamic of Nephrops in the Northwest Iberian coast. The results were compare with those obtained in the same stocks with other data-limited methods. Also the role of abiotic factors on the observed dynamic of the stocks was explored. The results of this study are not only relevant for the sustainable exploitation of Norway lobster stocks off the Northwest Iberian coast but provide valuable insights into the suitability and limitations of production models for the assessment of crustacean stocks in general.

The hexactinellid sponge Asconema setubalense Kent, 1870 is a deep-sea species characterized by its expansive cup-shaped morphology, which contributes significantly to the three-dimensional complexity of the marine ecosystems. This sponge forms grounds that offer protection to pelagic organisms and juvenile stages. Despite its ecological relevance, there is a lack of information on the ecology, behavior and population structure of this species. The research aimed to conduct a multitemporal analysis of this sponge in the Aviles Canyon System over a ten-year period, focusing on spatial distribution and abundance. Changes in fishing pressure were estimated using the presence of fishing gears as a proxy. Additionally, the study sought to provide a detailed morphometric description through 3D photogrammetric reconstructions based on the latest data. The multi-temporal analysis revealed a subtle increase in sponge density, particularly at depths ranging from 320 to 390 m, exhibiting an irregular spatial distribution in 2022, with maximal values of 0.08 individuals/m2. Despite a small decrease on the loss of fishing gears in the overlapping area between samplings in 2012 and 2022, there was not a clear indication of a decline in fishing pressure over the years. Notably, more sightings of fishing gears were found in transect IC222TV_16 (0.07 gears/m2) than in IC222_TV02 (0.04 gears/m2) in 2022, suggesting potential spatial preferences for fishing activities. Visual analysis of temporal populations revealed an increase of 7% in specimen perturbations over ten years, with the population in IC222_TV16 being healthier (9% of the individuals presenting severe deformations) than in IC222_TV02 (40%). High-density fishing gear locations coincided with areas inhabited by sponges displaying the highest perturbation levels in both transects. Morphometric analysis using data from 2022 indicated a prevalence of individuals with heights concentrated between 0.18 and 0.38 m, osculum and flounce diameters reaching 0.4 and 0.56 m and osculum and flounce surfaces of 0.02–0.04 and 0.06–0.19 m2 respectively. Over 80% of measured specimens exhibited a high degree of asymmetry. Strong correlations were observed between heights and osculum and flounce surfaces, but external factors may be included for explaining wall deformities. These findings contribute valuable insights into the characterization of A. setubalense , serving as a foundation for future research in the area. Moreover, this work highlights the promising potential of photogrammetry as an efficient tool for monitoring of vulnerable marine ecosystems (VME) and marine protected areas. • Photogrammetry effectively studies benthic communities without disturbance. • The Asconema setubalense population modestly increased from 2012 to 2022. • This rise may be attributed to protective policies, demonstrating their efficacy in preserving biodiversity. • Our current research has significantly expanded our understanding of the morphometric parameters associated with this species. [ABSTRACT FROM AUTHOR]

In the present work we focus on the distribution of two species of sponges. One of these is Asconema setubalense, a sponge found in rocky substrate that was sampled with a photogrammetric vehicle through georeferenced images. The other is Pheronema carpenteri, which inhabits soft bottoms and was sampled by beam trawl. For the spatial distribution modeling of both sponges, the geomorphological variables of depth, slope, broad and fine scale bathymetric position index (BPI), aspect, and types of bottoms were used, all with a resolution of 32 m. Additionally, layers of silicates and currents near the bottom were extracted from Copernicus Marine Environment Monitoring Service (CMEMS), with a resolution of ∼4 and ∼9 km, respectively. Due to the low resolution of the layers, it was considered necessary to validate their use by model comparison, where those that included these variables turned out to be more explanatory than the others. The models were developed in a complex continental break of the Central Cantabrian Sea, which comprises several submarine canyons and a seamount (Le Danois Bank). On the one hand, a very high resolution (32 m) spatial distribution model based on A. setubalense presence was developed using the MaxEnt maximum entropy model. On the other, depending on the availability of density data, generalized additive models (GAMs) were developed for P. carpenteri distribution, although in this case the sampler only allowed a maximum resolution of almost 1 Km. For the A. setubalense, the variables that best explained their distribution were ground types and depth, and for P. carpenteri, silicates, slope, northness, and eastward seawater velocity. The final model scores obtained were an AUC of 0.98 for the MaxEnt model, and an R squared of 0.87 for the GAM model.

In this work, we identified non-crustose invasive (Codium fragile subsp. fragile) and native Codium spp. (Codium tomentosum and Codium vermilara) in the central Cantabrian Sea using DNA barcoding (tufA and rbcL genes). We designed a new FCOtufA genetic marker for identifying Codium spp. in fresh and herbarium material. The tufA and rbcL sequences revealed three different single haplotypes for each of the species and a lack of intraspecific genetic diversity. The FCOtufA genetic marker revealed one new haplotype of C. fragile within the native region (South Korea), suggesting the possibility of higher genetic diversity in the donor region of this invasive species. [ABSTRACT FROM AUTHOR]

Background: Herpesvirus infections in cetaceans have always been attributed to the Alphaherpesvirinae and Gammaherpesvirinae subfamilies. To date, gammaherpesviruses have not been reported in the central nervous system of odontocetes. Case presentation: A mass stranding of 14 striped dolphins (Stenella coeruleoalba) occurred in Cantabria (Spain) on 18th May 2019. Tissue samples were collected and tested for herpesvirus using nested polymerase chain reaction (PCR), and for cetacean morbillivirus using reverse transcription-PCR. Cetacean morbillivirus was not detected in any of the animals, while gammaherpesvirus was detected in nine male and one female dolphins. Three of these males were coinfected by alphaherpesviruses. Alphaherpesvirus sequences were detected in the cerebrum, spinal cord and tracheobronchial lymph node, while gammaherpesvirus sequences were detected in the cerebrum, cerebellum, spinal cord, pharyngeal tonsils, mesenteric lymph node, tracheobronchial lymph node, lung, skin and penile mucosa. Macroscopic and histopathological post-mortem examinations did not unveil the potential cause of the mass stranding event or any evidence of severe infectious disease in the dolphins. The only observed lesions that may be associated with herpesvirus were three cases of balanitis and one penile papilloma. Conclusions: To the authors' knowledge, this is the first report of gammaherpesvirus infection in the central nervous system of odontocete cetaceans. This raises new questions for future studies about how gammaherpesviruses reach the central nervous system and how infection manifests clinically. [ABSTRACT FROM AUTHOR]

The occurrence of the flexed verticord, Halicardia flexuosa (Verrill & S. Smith [in Verrill], 1881), is reported for the first time from the Bay of Biscay (North Iberian Peninsula). This rare bivalve was collected from deep waters (1200 m depth) of the Avilés Canyon Systems (Central Cantabrian Sea). We provide a detailed description and illustration of the species, as well as brief notes on its ecology at the new locality and its global biogeography. [ABSTRACT FROM AUTHOR]

The accumulation of contaminants in aquatic organisms is of concern to human health due to the potential for exposure through the consumption of seafood. This dataset presents the levels of 17 polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), and 12 dioxin-like polychlorinated biphenyls (DL-PCBs) (PCB-81, PCB-77, PCB-126, PCB-169, PCB-123, PCB-118, PCB-114, PCB-105, PCB-167, PCB-156, PCB-157 and PCB-189) in bivalves collected annually between 2008 and 2023 from the four Shellfish Production Areas of the Basque coast (southeastern Bay of Biscay). Additionally, data on 6 non-dioxin like polychlorinated biphenyls (NDL-PCBs) (PCB-28, PCB-52, PCB-101, PCB-153, PCB-138 and PCB-180) is provided for the 2012-2023 time period. Depending on the availability of bivalves at each Shellfish Production Area, different species, such as mussels ( Mytilus galloprovincialis ) and oysters ( Magallana gigas and Ostrea edulis ) were used for the evaluation. Bivalve samples were analyzed at the accredited Laboratory of Dioxins of the Institute of Environmental Assessment and Water Research - CSIC in Spain, following standardized methodologies according to the specific requirements established at the corresponding EU Regulation. Concentrations and the World Health Organization-Toxic Equivalents (WHO-TEQ) were calculated. Considering the data from the four Shellfish Production Areas and the study period, WHO-TEQ values ranged from 0.12 to 0.64 pg g -1 wet weight for PCDD/Fs and from 0.45 to 2.23 pg g -1 wet weight for DL-PCBs, whereas concentrations ranged from 7.45 to 51.10 ng g -1 wet weight for NDL-PCBs. This database is useful for (i) assessing the spatial and temporal trends of PCDD/Fs and various PCBs in bivalves from the Basque coast, (ii) determining the relative contribution of different congeners, (iii) comparison with levels for human consumption and environmental quality standards, as well as with levels of other biogeographical areas, and (iv) the management of Shellfish Production Areas on the Basque coast., (© 2023 The Authors. Published by Elsevier Inc.)

Abstract The cold-water coral (CWC) Dendrophyllia cornigera is widely distributed in areas of both high and low productivity, suggesting a significant trophic plasticity of this coral depending on the food available in the environment. In this study, lipid biomarkers and their isotopic signature were compared in colonies of D. cornigera and sediment from the highly productive Cantabrian Sea (Northeast Atlantic Ocean) and the less productive Menorca Channel (Western Mediterranean Sea). Lipid content and composition in coral tissue clearly reflected the contrasting productivity in the two areas. Cantabrian corals presented higher content in fatty acids (FA), fatty alcohols and sterols than Menorca corals. Energy storage (saturated + mono-unsaturated FA) to structural (poly-unsaturated FA) ratio was higher in Cantabrian than in Menorca corals. The high ΣC20:1 content as well as PUFA (n-3) /PUFA (n-6) ratio suggest that Cantabrian corals mainly feed on phytoplankton and herbivorous grazers. This is also supported by the higher mono-unsaturated fatty alcohols (MUOH) and long chain mono-unsaturated fatty alcohols (LCMUOH) content in Cantabrian compared to Menorca corals. Conversely, higher PUFA (n-6) content in Menorca corals, with the dominance of C22:4 (n-6) and C20:4 (n-6) , as well as the dominance of cholesterol and norC 27 Δ5,22 among sterols, point to a higher trophic role of dinoflagellates and invertebrates. The observed geographical variability in trophic ecology supports a high trophic plasticity of D. cornigera , which may favour the wide distribution of this CWC in areas with highly contrasted food availability. Highlights • Higher lipid content in D. cornigera in Cantabrian Sea than in Menorca Channel. • Lipid composition and δ 13C values reflected contrasted food captured by corals. • Feeding on phytoplankton and herbivorous grazers by Cantabrian D. cornigera. • Main trophic role of dinoflagellates and invertebrates for Menorca D. cornigera. • High trophic plasticity of D. cornigera. [ABSTRACT FROM AUTHOR]

A new species of holothurian of the genus Psolus Oken, 1815 is described. Psolus rufus sp. nov. was found in the central Cantabrian slope (Bay of Biscay) at 1500 m depth. The new species is characterized by having: ovoid body, reddish colour in vivo ; dorsal area enclosed in a complete test composed of imbricating scales; 10 triangular plates of the same size surrounding mouth; 10 oral tentacles; no dorsal papillae; tube feet in two rows in the ventrolateral radii but one single row in the medial third or the body; ossicles are big dorsal plates and small plates in the sole, which are smooth, irregular and perforated. The molecular study of the COI gene supports the morphological results, grouping P. rufus sp. nov. together with other members of the genus. However, the new species is genetically distinct from the two groups (Antarctic and Canadian) of the available sequenced Psolus species. Furthermore, a key to the Psolus species of the north-eastern Atlantic Ocean is provided. [ABSTRACT FROM AUTHOR]

Guilds first emerged at the heart of the feudal mode of production, but when this disappeared and they were banned, they had to adapt to new mode of production and now remain an essential part of the small-scale fishing system on the Cantabrian Sea and elsewhere within the Spanish State. Fishing businesses used cooperation mechanisms originating from the old guilds, reconverting them into strategic alliances for market economies. That has been one of the basic reasons for their hyperlongevity, despite the fact that frequently a bleak future had been forecast for them. Many specific demands related to the fishing needs of each port have arisen over such a long period of time and over such a large area. The cofradías, the current version of ancient guilds, have been the tool used to deal with these demands by taking advantage of the potential provided by their flexibility and their possibilities for addressing problems cooperatively in each specific circumstance. Once such a tool had been designed, the small-scale fishing subsector then had a mechanism at its disposal with great potential for addressing countless problems related to the production of goods and services that needed cost and risk distribution among its members. In the case of the most recent alliance variants involving cooperation, cofradías have been associated with other fishing bodies – both public and private – who share similar interests over fish stocks and markets. That is why they retain currently the trust and financial backing of the small-scale fishing sector. [ABSTRACT FROM AUTHOR]

Recent changes in climate and oceanographic conditions have been affecting the dynamics and composition of species communities worldwide, increasing the occurrence of tropical-subtropical species within a specific biogeographic area. This phenomenon defined as tropicalization is occurring in the Cantabrian Sea (Bay of Biscay), a transitional zone between two different regions of the North Atlantic. In this study we present new records of the tropical-subtropical gastropod species Plicopurpura patula and Monoplex parthenopeus in the European Atlantic, which constitute their northernmost distribution in the Atlantic Ocean to date. We provide a detailed characterization of both species, combining morphological and molecular features. Finally, supported by provided evidence and justification, we propose both species as two new potential bioindicators of the tropicalization phenomenon in the North Atlantic waters. • The Cantabrian Sea (Bay of Biscay) is an interesting area to study the tropicalization. • This regional sea constitutes a transitional zone between two different ecoregions. • News records of two tropical/subtropical gastropods in the Cantabrian Sea, constituting their northernmost distribution in the Atlantic. • Cantabrian P. patula and M. parthenopeus specimens were morphologically and genetically characterized. • We propose both species as two new bioindicators of tropicalization in the Atlantic. [ABSTRACT FROM AUTHOR]

“El Cachucho” Marine Protected Area (MPA), which comprises Le Danois Bank and its intraslope basin, was included during 2008 in the Nature 2000 network mainly because of the presence of the habitat “1170 Reefs” according to the EU Habitat Directive. To review the effectiveness of existing management measures, several activities aimed at characterizing the most structurally complex hard-bottom habitats were planned and carried out during the ESMAREC 0514 survey. For identification of these habitats, several transects using the photogrammetric towed sled Politolana were carried out on Le Danois Bank, in the depth range between 427 and 1379 m, searching for the sea beds with higher values of slope and backscatter. Photogrammetric techniques were used for image scaling, so we could determine the surface areas of different substrata types (facies) and their species densities. A total area of 28,762 m 2 was analyzed in the still images of 23 transects, verifying that 85% of the substrata of our study area are occupied by 4 different facies: Bedrock, bedrock with mixed sediments, mixed sediments with pebbles and boulders, and mixed sediments. Acoustic data and ground-truth visual data were combined to evaluate distinctive benthic scenarios. The relative abundances of the 123 epibenthic species identified by image analyses show that the most abundant are sponges (29%), cnidarians (26%), crustaceans (26%) and echinoderms (14%), i.e. mostly sessile species or those with low mobility. The keystone species of the “1170 Reefs” habitat are 3 cnidarians: Callogorgia verticillata , Paramuricea cf. placomus and Dendrophyllia cornigera, and 3 sponges, Asconema setubalense , Geodia msp.1 and Phakellia robusta . Eight new habitats (biotopes) have been identified on Le Danois Bank, six of which occur on the hard bottoms, with depth, substratum, BPI (Bathymetric Position Index) and slope as determining environmental variables that explain their spatial distributions. [ABSTRACT FROM AUTHOR]

Low concentrations of azaspiracids have been found in bivalve molluscs all over the Northern and Northwestern coast of the Iberian Peninsula. The detections started in June 2016 and lasted until March 2017. The observed toxin profile was dominated by AZA2, followed by AZA1 and some other AZAs that were detected only in some samples. Some compounds producing fragments characteristics of AZAs but that do not fit with any of the known ones were also found. The causative agent has not been identified but, in sight of the toxin profile in the bivalves, it seems that it should be a new species or strain. The detections of AZAs in bivalves in the Northern Coast was linked to downwelling or upwelling relaxation and, in the Galician Rías, took place (with only a few exceptions) in the outer (more oceanic) part, suggesting that the responsible species develops at the open sea and that the populations are advected to the shore. [ABSTRACT FROM AUTHOR]

Discard management needs to draw on scientific research and advice, usually supported by specific statistical modeling analysis. A wide range of statistical analysis methods were applied to fishery data in an attempt to distinguish factors that influence the species discard composition. While such approaches are important, they are still incomplete for disaggregating the economic and spatial-temporal factors for analyzing of this process and obtain a whole view of this issue. Our study aims to fill this gap by identifying, describing, and quantifying factors that influence discards of trawl fisheries using a multivariate approach based on five complementary aspects: “economic”, “vessel characteristics”, “spatial”, “temporal” and “environmental”. In addition, a spatial multi-criteria approach were used to investigate discard hot-spot areas using ecological criteria such as vulnerability and resilience of the discarded species. Using these ecological criteria will concentrate conservation efforts on the most relevant sites minimizing discards of a variety of potentially vulnerable species. This approach was applied to a case study of a multi-species demersal bottom trawl fisheries in north Spain, Cantabrian Sea (ICES area VIIIc). Results showed how spatial and economic factors highly affect species discard composition, identifying specific spatial-temporal discard hot-spots to be preferentially avoided by fishers. Mitigation measures for future fisheries management strategies should be implemented at multiple stages of the discarding process, both in the selection of the fishing grounds and the economic valorization of the discarded species. [ABSTRACT FROM AUTHOR]

This work assesses for the first time the offshore wind energy resource in Asturias, a region in the North of Spain. Numerical model and observational databases are used to characterize the gross wind energy resource at different points throughout the area of study. The production of several wind turbines is then forecasted on the basis of each technology power curve and the wind speed distributions. The results are mapped for a better interpretation and discussion.

Fractionation of the bioactive extract of a culture of the marine derived actinomycete Streptomyces cyaneofuscatus M-157 led to the isolation of the known 3-hydroxyquinaldic acid (4), its amide (5) and three new derivatives (1–3) containing different amino acid residues. The structures of the new molecules (1–3), including their absolute configuration, were determined by the analysis of their ESI-TOF MS and one-dimensional (1D) and two-dimensional (2D) NMR spectra and advanced Marfey’s analysis of their hydrolyzation products. Compound 3 spontaneously dimerized in solution to give the disulfide derivative 6. Unfortunately, none of the new compounds isolated confirmed the antimicrobial activity found in the bacterial extract, perhaps indicating that such antibacterial activity might be due to presence in the extract at the trace level of larger bioactive 3-hydroxyquinaldic acid derivatives from which compounds 1–3 are biosynthetic precursors. Cytotoxicity tests confirmed the moderate and weak IC50 values of 15.6 and 51.5 µM for compounds 5 and 1, respectively.

The potent antimicrobial extract of a culture of the marine derived actinomycete Streptomyces cyaneofuscatus M-169 was fractionated by reversed phase flash chromatography and preparative HPLC to yield the new Gram-positive antibiotic, anthracimycin B (1), together with its congener, anthracimycin (2). The structure of the new compound was established by analysis of its ESI-TOF MS and 1D and 2D NMR spectra, and comparison with data published for anthracimycin and anthracimycin BII-2619 (3). Notably, anthracimycin seemed to be the major and almost unique component of the extract detected by HPLC-UV-MS, making our S. cyanofuscatus strain an excellent candidate for further biosynthetic studies of this potent antibiotic.

Diet analysis of larval fish may clarify the role that zooplankton—not only its abundance but also its size structure and taxonomic composition—may have on larval growth and subsequent recruitment levels. Taking into account the increase in size during larval stages, we followed a larval size-dependent approach for the analysis of prey size in the diet of larval sardine (Sardina pilchardus). Studies on feeding patterns of clupeid larvae typically involve a problem due to regurgitation and defecation of gut contents during capture. Therefore, an alternative sampling method was tested in this study, but no significant differences from conventional methods were found. Despite the low feeding incidence observed (23%), we found a circadian feeding pattern with the highest mean gut contents after dawn, decreasing during the day and with the lowest values at night. Diet was mostly composed of copepod developmental stages, mainly nauplii, and prey size increased with larval size following a power function. Maximum and mean prey size were related to larval mouth gape, though other factors may be restricting the maximum prey size ingested, since most prey width values were between 20 and 40% of larval mandible width.

Size fractionated mesozooplankton biomass, abundance and copepod grazing were investigated over an annual cycle (1998) at two stations off Cudillero (central Cantabrian Sea). Mesozooplankton biomass was higher in summer/early autumn, reaching ~3000 mg dw m-2 in September. Copepods were the most abundant taxonomic group, representing 91 and 81% of the total mesozooplankton abundance in the coastal and shelf-break station respectively. Copepod gut contents were higher in summer at the coastal station, while the shelf-break station showed maximum gut contents in April. Gut contents were linearly related to integrated chlorophyll, except in the case of large animals at the shelf break station. Copepod community carbon ingestion was higher from June to September at both stations, reaching a maximum value of ~165 mg C m-2 day-1. Calculated grazing rates translates into an average daily consumption values of 8.7% (coast) and 5.25% (shelf-break) of total chlorophyll stock, or 20% (shelf-break) of total primary production.

Background: The introduction of NIS to estuaries and coastal embayment is of great concern. Commercial ships' ballast water discharge and the northwards progression of species due to the ongoing climate change arise as the main factors explaining the rising occurrence of NIS species in Northern Atlantic waters. In this regard, regular monitoring of the plankton communities is paramount as to be able to respond properly to this potential issue. Results: While monitoring the invasive copepod Acartia tonsa populations in the estuaries of Bilbao and Urdaibai (Basque country, Spain), we report here the Asian copepod Pseudodiaptomus marinus for the first time in the Iberian Peninsula waters. Individuals from both species were collected from July to October, 2013 for DNA sequencing of mitochondrial cytochrome c oxidase subunit I gene (MT-CO1). Phylogenetic analysis of MT-CO1 confirmed P. marinus identity. Conclusions: Phylogeographic distribution of A. tonsa haplotypes in Europe along with the Bilbao port traffic patterns suggested a secondary invasion from an European source to Basque estuaries. The successful establishment of the A. tonsa population and the appearance of Pseudodiaptomus marinus confirm the need for regular plankton monitoring of estuarine and port waters. This applies also to nearby systems as these populations could represent a source of future dispersal. [ABSTRACT FROM AUTHOR]

This series of digital images is inspired by the ancient hand paintings discovered in caves close to the Cantabrian Sea along the northern coast of Spain. The five images are a further contribution to New Male Studies by the Danish photographer Jan H. Andersen. [ABSTRACT FROM AUTHOR]

An annotated check-list of the marine benthic flora of the Spanish Basque coast, based on literature records and original data, is presented. According to the present taxonomy, the known list of algae totals 372 taxa (354 species and 18 infraspecific taxa), distributed as follows: 23 Cyanophyta, 221 Rhodophyta, 74 Heterokontophyta and 54 Chlorophyta. In addition, 16 taxa are considered as taxa inquirenda and 8 as taxa excludenda. For each taxon the vertical distribution, abundance estimation, and two first published records are given. Remarks on the most noteworthy features of the flora of the study area are included. The floristic character of Spanish Basque coast flora was compared with nearby regions applying Cheney’s ratio [(Rhodophyta+ Chlorophyta)/Phaeophyta, or (R+C)/P]. The resulting high value (4,09) indicates its warm-water character, which was already noted at the end of the XIX century. From a physionomical point of view, Basque benthic vegetation resembles more closely that of southern regions (S Portugal, Morocco). The warming process of waters off the Basque coast during summer up to 22 ºC is responsible for the absence or very rare occurrence of cold temperate species like large fucoids and kelps, which are common in Galicia and Brittany, and explains the abundance of numerous warm-temperate species as ceramiaceous algae.

In an attempt to detect changes in the diet and the feeding intensity of demersal fish caused by fishery discarding, two hauls were carried out 22 h apart at a depth of 90 m in an area of the Cantabrian Sea closed to trawling. Before the second haul, dead fauna that were not common in the sampling area under natural conditions, such as Micromesistius poutassou and squat lobster (Munida spp.), which are both usually discarded by the fleet and mainly found in deeper water, were thrown overboard. A total of 319 stomach contents from 12 demersal fish species caught in both hauls were analysed. The percentage emptiness decreased in the second haul (32%) with respect to the first (43%), and at the same time the feeding intensity of scavenger species such as Trachinus draco, Pagellus acarne, Scyliorhinus canicula, Raja montagui and Leucoraja naevus increased. Discards of M. poutassou was actually found in the stomach of a typically planktophagous species, Pagellus bogaraveo. Observed changes in trophic structure of the species analysed as a response to discards are discussed.

There are currently no dedicated recruitment survey data available in support of the assessment of the abundance and distribution of Northeast Atlantic (NEA) mackerel (Scomber scombrus), one of the most widespread and commercially important fish stocks in the North Atlantic. This is despite the fact that an estimate of recruitment is an important requirement for the provision of advice to fishery managers. The work here addresses this by compiling catch rates of juvenile mackerel from bottom-trawl surveys conducted between October and March during 1998-2012 and applying a log Gaussian Cox (LGC) process geostatistical model incorporating spatio-temporal correlations. A statistically significant correlation between the modelled catch rates in adjacent quarters 4 and 1 (Q4 and Q1 ) demonstrates that bottom-trawl surveys in winter are an appropriate platform for sampling juvenile mackerel, and that the LCG model is successful in extracting a population abundance signal from the data. In this regard, the model performed appreciably better than a more commonly used raising algorithm based on survey swept-area estimates. Therefore, the LCG model was expanded to include data from the entire survey time-series, and a recruitment index was developed for use in the annual ICES stock assessment. We hypothesize that catchability is positively density-dependant and provides supporting evidence from acoustic observations. Various density-dependant transformations of the modelled catch rates were furthermore found to improve the correlation between the derived annual recruitment index and recruitment estimated by back-calculation of adult mackerel data. Square root transformation led to the strongest correlation, so this is recommended for further analysis of mackerel abundance. Finally, we provide maps of spatial distributions, showing that the most important nursery areas are around Ireland, north and west of Scotland, in the northern North Sea north of 59°N and, to some extent, also in the Bay of Biscay. [ABSTRACT FROM AUTHOR]