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The survival of Atlantic salmon (Salmo salar), an increasingly rare anadromous species, has declined dramatically during its marine phase, with disproportionate impacts on the poorly understood early post-smolt period. Logistical constraints on collecting oceanic data to inform this issue pose a formidable obstacle. To advance understanding of post-smolt distributional ecology in the North-east Atlantic, a comprehensive analysis of existing information was undertaken. Data were synthesized from 385 marine cruises, 10,202 individual trawls, and 9,269 captured post-smolts, spanning three decades and ~4.75 million km2 of ocean, with 3,423 individuals genetically assigned to regional phylogeographic origin. The findings confirm major migrational post-smolt aggregations on the continental shelf-edge off Ireland, Scotland and Norway, and an important marine foraging area in the Norwegian Sea. Genetic analysis shows that aggregational stock composition does not simply reflect distance to natal rivers, with northern phylogeographic stock groups significantly under-represented in sampled high-seas aggregations. It identifies a key foraging habitat for southern European post-smolts located in international waters immediately west of the Vøring Plateau escarpment, potentially exposing them to a high by-catch mortality from extra-territorial pelagic fisheries. Evidence of the differential distribution of regional stocks points to fundamental differences in their migration behaviours and may lead to inter-stock variation in responses to environmental change and marine survival. The study shows that understanding of post-smolt marine ecology, as regards to stock-specific variations in habitat utilization, biological performance and exposure to mortality factors, can be significantly advanced by data integration across studies and exploiting genetic approaches.

[EN] Conservation and sustainable management of aquatic ecosystems is a priority in environmental programs worldwide. However, these aims are highly dependent on the efficiency, accuracy and cost of existent methods for the detection of keystone species and monitoring of biological communities. Rapid advances in eDNA, barcoding and metabarcoding promoted by high-throughput sequencing technologies are generating millions of sequences in a fast way, with a promising cost reduction, and overcoming some difficulties of the traditional taxonomic approaches. This paper provides an updated broad perspective of the current developments in this dynamic field presented in the special session (SS) “The use of molecular tools in ecological and biodiversity assessment of aquatic ecosystems” of the XIX Congress of the Iberian Association of Limnology (AIL2018), held in Coimbra, Portugal. Developments presented are mainly focused on the Iberian Peninsula (Portugal and Spain, including Atlantic Macaronesian islands) but include studies in France, Germany, Finland, Russia (Siberia) and South America. The networks within which these researchers are involved are yet even broader, profiting from existing molecular facilities, and traditional taxonomic expertise, which can be viewed as a characteristic of this new research area. It was evident in the SS that the use of molecular tools is widespread, being used to study a diversity of aquatic systems, from rivers’ headwaters to estuaries and coastal lagoons, and volcanic, mountain and frozen lakes to hot springs. The organisms targeted are likewise varied and include fish, macroinvertebrates, meiofauna, microalgae such as diatoms and dinoflagellates, other protists, fungi, and bacteria (cyanobacteria and other). Some studies address the whole biodiversity (i.e., all species present independently of the taxonomic group) from environmental samples of water, biofilms and preservative solution from field samples (e.g., ethanol from macroinve, [ES] A conservação e gestão sustentável dos ecossistemas aquáticos é uma prioridade nos programas ambientais em todo o mundo. No entanto, esses objetivos são altamente dependentes da eficiência, precisão e custo dos métodos existentes para detectar espécies e monitorizar comunidades biológicas. Avanços recentes no que respeita ao ADN ambiental e ‘barcoding’ e ‘meta-barcoding’, promovidos por tecnologias de sequenciação designadas ‘high-throughput sequencing’, têm gerado milhões de sequências de forma rápida, com uma promissora redução de custos num futuro próximo, e superando algumas dificuldades das abordagens taxonómicas tradicionais. Este artigo vem fornecer uma perspetiva atualizada e abrangente dos desenvolvi-mentos neste campo que foram apresentados na sessão especial (SE) “O uso de ferramentas moleculares na avaliação ecológi-ca e da biodiversidade dos ecossistemas aquáticos”, no XIX Congresso da Associação Ibérica de Limnologia (AIL2018) realizado em Coimbra, Portugal.Os desenvolvimentos apresentados centram-se principalmente na Península Ibérica (Portugal e Espanha, incluindo as ilhas atlânticas), mas também em França, Alemanha, Finlândia e Rússia (Sibéria). No entanto, as redes em que estes investigadores estão envolvidos são ainda mais amplas, aproveitando as infraestruturas moleculares e o conhecimento taxonómico existentes. Ficou claro na SE que o uso de ferramentas moleculares está disseminado, sendo usado numa diversidade de sistemas aquáti-cos, desde as cabeceiras dos rios aos estuários e lagoas costeiras, e desde lagos vulcânicos, de montanha e congelados, a fontes termais. Os organismos estudados são também variados e incluem peixes, macroinvertebrados, meiofauna, microalgas tal como diatomáceas e dinoflagelados, outros protistas, fungos e bactérias (cianobactérias e outros). Alguns estudos abordam toda a biodiversidade a partir de amostras ambientais de água, biofilmes e solução conservante. Grandes avanços foram reconhecidos na sessão especial, n

Many Atlantic salmon Salmo salar populations in Europe are threatened by previous stocking with foreign hatchery strains. Temporal patterns of genetic characteristics of salmon from northern Spain, the southernmost European populations, were compared before and after species decline and heavy stocking with specimens from northern Europe. Eleven microsatellite loci were analysed in archival (scales from 1958-1960) and contemporary (2007-2008) samples from the River Sella. Temporal analyses revealed a similar heterozygosity between archival and contemporary samples, despite a drastic decrease in population abundance, while the contemporary sample showed a higher allelic richness due to the occurrence of foreign alleles. Considering only the alleles with at least 4% frequency in the archival sample, 2 alleles exclusive to the River Sella were absent in the contemporary sample, and 14 alleles showed a decrease of at least 4% frequency. Four alleles common in Scotland showed a high occurrence in the contemporary sample, so they are good candidates as markers of introgression of foreign genes. The heavy stocking with non-native Scottish broodstocks between 1970 and 1990 caused the introgression found in the contemporary sample when compared with the pristine population. An abrupt decrease was evident when the estimates of effective number of breeders were adjusted to take into account overlapping generations (Nb), effective population size (Ne) estimated from Nb, and number of breeders estimated using the sibship assignment method (Nb). The very low effective size values found in the contemporary sample, together with the detrimental synergy between genetic drift and high rates of introgression, represent a severe risk for the conservation of native salmon.

This study was supported by the Regional Government of Asturias (Grant GRUPIN-2014-093). M. Muñoz-Colmenero holds a national Spanish Grant (reference AP-2010-5211)., Fish consumption has many health benefits, but may encompass some risks such as allergic reactions. The main responsible of fish allergy is parvalbumins, being one of the most common parvalbumin beta 1 proteins (Pvalb1) in many fish species. IgE-mediated cross-reactivity may occur between Pvalb1 of different species, and there are also cases of species-specific allergic reactions for only a few fish species. The frequent exchanges Salmo and Oncorhynchus genera found in commercial products demonstrate the great need to continue investigating new tools for the control of mislabeling. In this study, we have amplified by PCR, the parvalbumin beta 1 gene, and analyzed the intron and exon diversity in three genera (Oncorhynchus, Salmo, and Salvelinus), to evaluate the variability of this gene in Salmonids’ group. High variability and occurrence of species-specific SNPs found make this gene suitable as powerful species identification tool. In addition, three putative proteins were inferred from translated DNA sequences, which are worthy to investigate, because of their potentially different effect in the fish allergic reaction of salmonid-sensitive consumers., Depto. de Genética, Fisiología y Microbiología, Fac. de Ciencias Biológicas, TRUE, pub

Atlantic salmon (Salmo salar L.) populations from different river origins mix in the North Atlantic during the marine life stage. To facilitate marine stock identification, we developed a genetic baseline covering the European component of the species' range excluding the Baltic Sea, from the Russian River Megra in the north-east, the Icelandic Ellidaar in the west, and the Spanish Ulla in the south, spanning 3737 km North to South and 2717 km East to West. The baseline encompasses data for 14 microsatellites for 26 822 individual fish from 13 countries, 282 rivers, and 467 sampling sites. A hierarchy of regional genetic assignment units was defined using a combination of distance-based and Bayesian clustering. At the top level, three assignment units were identified comprising northern, southern, and Icelandic regions. A second assignment level was also defined, comprising eighteen and twenty-nine regional units for accurate individual assignment and mixed stock estimates respectively. The baseline provides the most comprehensive geographical coverage for an Atlantic salmon genetic data-set, and a unique resource for the conservation and management of the species in Europe. It is freely available to researchers to facilitate identification of the natal origin of European salmon.

This study was supported by the Principality of Asturias under the Grant GRUPIN-2014-093. MMC holds a Spanish National Grant (FPU) (reference AP-2010-5211)., Mislabeling of seafood species has negative economic, social and ecological consequences, from consumer losses due to fraudulent exchange, undermining consumer awareness, to hiding illegal and unreported catches. Salmonids are no exception. They are an important part of the culture and economy of many countries in the northern hemisphere, and identifying possible causes of salmon mislabeling is of great interest, even more so where wild species and species from aquaculture are consumed. Here different types of commercial unrecognizable salmonid products (111 in total) from Asturias in Northwest Spain (Atlantic Ocean), and Alaska and Vancouver Island in Northwest America (Pacific Ocean) were analyzed by DNA Barcoding. The Spanish and Northwest American samples were mislabeled 6% and 23.8% respectively. Species substitutions were respectively wild-farmed and wild-wild, substitute species being cheaper. Economic reasons and social preference of wild over farmed products seem to be the main drivers in the exchanges detected in this study. Enhancing controls over the unrecognizable products to prevent this type of fraud is essential and strongly recommended., Depto. de Genética, Fisiología y Microbiología, Fac. de Ciencias Biológicas, TRUE, pub

This study has been funded by the Spanish Ministry of Economy and Competitiveness, Grant CGL-2013-42415-R and the Principality of Asturias (Spain), Grant GRUPIN-2014-093. This is a contribution from the Marine Observatory of Asturias (OMA). Alba Ardura is recipient of a Postdoctoral Fellowship with reference Clarin-CO-FUND-PCTI-FICYT. Laura Clusa holds a PCTI Grant from the Asturias Regional Government, referenced BP14-145., The tubeworm Ficopomatus enigmaticus is a highly invasive species with an increasingly expanding distribution in Europe and America. In port areas it causes damage to structures and sewage systems because it is an active reef builder. Having short generation time and high reproduction capacity it is especially important to detect the species before it is fully settled down. Here we have designed a PCR-based species-specific molecular marker within the Cytochrome Oxidase subunit I gene (COI). The new marker was validated in vitro and from field water samples obtained in southwest Bay of Biscay ports (north of Spain). The species was detected only from eDNA in Villaviciosa port, where it was not found de visu in the intertidal zone and floating structures. Adults were found in the same port one year later as confirmed taxonomically and by conventional barcoding, which confirms the utility of the new eDNA marker for early detection of F. enigmaticus. This new and cheap molecular tool could be used for routine monitoring of coastal areas, in order to early detecting this invasive species., Depto. de Genética, Fisiología y Microbiología, Fac. de Ciencias Biológicas, TRUE, pub

The Next Generation Sequencing methodologies are considered the next step within DNA-based methods and their applicability in different fields is being evaluated. Here, we tested the usefulness of the Ion Torrent Personal Genome Machine (PGM) in food traceability analyzing candies as a model of high processed foods, and compared the results with those obtained by PCR-cloning-sequencing (PCR-CS). The majority of samples exhibited consistency between methodologies, yielding more information and species per product from the PGM platform than PCR-CS. Significantly higher AT-content in sequences of the same species was also obtained from PGM. This together with some taxonomical discrepancies between methodologies suggest that the PGM platform is still pre-mature for its use in food traceability of complex highly processed products. It could be a good option for analysis of less complex food, saving time and cost per sample., Ministerio de Universidades, Principado de Asturias, Fundación Mafre, Depto. de Genética, Fisiología y Microbiología, Fac. de Ciencias Biológicas, TRUE, pub

Funding Este estudio fue parcialmente financiado por el Máster Erasmus Mundus en Conservación de la Biodiversidad Marina y la Consejería de Educación y Ciencia del Principado de Asturias y por la Beca SV-PA-13-ECOEMP-41 del Principado de Asturias., The subfamily Polycerinae includes four genera with around 46 species described to date. This subfamily is characterized by a limaciform body, which may have simple tentacular processes on the margin of the oral veil. Phylogenetic relationships between the genera of the subfamily Polycerinae (Polyceridae) have not yet been studied, and therefore, the only available information is based on morphological descriptions. The present study reports the first phylogenetic analysis of Polycerinae based on the mitochondrial genes cytochrome oxidase subunit I and the large ribosomal subunit (16S rRNA) using maximum likelihood and Bayesian methods. Our results showed that Polycerinae is monophyletic, but the relationships within the subfamily as well as within Polycera remain unresolved. A key finding of this study is that there are clearly two sympatric species of Polycera present in South Africa: Polycera capensis Quoy and Gaimard, 1824 also found in Australia and an undescribed Polycera sp. On the other hand, the studied specimens of the genus Gymnodoris were clustered within Polycerinae, reopening the problem of the systematic position of this genus. Additional genes and species of Polycerinae and Gymnodoris would provide more information and probably fully resolve this situation., Principado de Asturias, Depto. de Genética, Fisiología y Microbiología, Fac. de Ciencias Biológicas, TRUE, pub

Visual species identification of cetacean strandings is difficult, especially when dead specimens are degraded and/or species are morphologically similar. The two recognised pilot whale species (Globicephala melas and Globicephala macrorhynchus) are sympatric in the North Atlantic Ocean. These species are very similar in external appearance and their morphometric characteristics partially overlap; thus visual identification is not always reliable. Genetic species identification ensures correct identification of specimens. Here we have employed one mitochondrial (D-Loop region) and eight nuclear loci (microsatellites) as genetic markers to identify six stranded pilot whales found in Galicia (Northwest Spain), one of them of ambiguous phenotype. DNA analyses yielded positive amplification of all loci and enabled species identification. Nuclear microsatellite DNA genotypes revealed mixed ancestry for one individual, identified as a post-F1 interspecific hybrid employing two different Bayesian methods. From the mitochondrial sequence the maternal species was Globicephala melas. This is the first hybrid documented between Globicephala melas and G. macrorhynchus, and the first post-F1 hybrid genetically identified between cetaceans, revealing interspecific genetic introgression in marine mammals. We propose to add nuclear loci to genetic databases for cetacean species identification in order to detect hybrid individuals.

This study was supported by the Spanish project MICINN CGL2009-08279 and the Regional Project FICYT IB09-0023. P.T. holds a PCTI grant (reference BP08-077)., Human activities have an impact on extant biotic communities, and may have had just as important an impact in the past. We assess human impact on limpet assemblages during the Upper Palaeolithic in Asturias (north-west Spain). The intensely exploited genus Patella exhibited a marked size decrease and a change in species assemblage composition, substituting the larger species P. vulgata for the smaller P. depressa. The present Patella assemblages in the upper tidal level exhibit the same pattern as those of the Epipalaeolithic (approx. 12 000 to 6000 years before the present). Although climate change may have contributed to such species replacement, spatial differences between close areas with different densities of Palaeolithic human settlements indicate unequivocal human impact. Present Patella species sampled from the region exhibit genetic signatures of past bottlenecks in mitochondrial DNA, which also indicate recent demographic expansion, suggesting that old impacts have been sufficiently important to leave genetic traces in current populations., Depto. de Genética, Fisiología y Microbiología, Fac. de Ciencias Biológicas, TRUE, pub