The benefit-risk analysis of omega-3 polyunsaturated fatty acids and heavy metals in seven smoked fish species from Siberia

In cold-smoked species of genus Coregonus, identified by molecular genetic analysis, contents of fatty acids and heavy metals and arsenic were measured. The highest content of sum of long-chain polyunsaturated fatty acids of omega-3 family (LC-PUFA), namely eicosapentaenoic (EPA) and docosahexaenoic (DHA) fatty acids, 6.53 ± 0.78 mg g−1 wet weight, was characteristic of tugun Coregonus tugun. This is the first quantitative estimation (mg LC-PUFA per g of product) of the nutritive value of smoked fish. Thus, to obtain a daily personal doze of EPA+DHA of 1 g, recommended for prevention of cardiovascular diseases, one needs to consume 153 g of the smoked tugun. Metals' contents did not exceed standards for fish meat except Pb in least cisco Coregonus sardinella. Accordingly, values of hazard quotients, which estimate benefit-risk ratio of fish intake, indicate that most of the smoked fish species are safe product for human nutrition, except least cisco regarding Pb content

Advances in the use of molecular tools in ecological and biodiversity assessment of aquatic ecosystems

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 macroinvertebrate samples). Great advances were acknowledged in the special session, namely in the use of metabarcoding for detecting hidden biodiversity, juvenile stages, low-abundance species, non-indigenous species and toxicity potential, and ultimately for ecological monitoring of diatoms and invertebrates. Yet, several drawbacks were highlighted and need further work, which include: taxonomic gaps in the reference databases (including gaps at species level and on intraspecific variability) or absence of public databases (e.g. for meiofauna), still high sequencing costs, the need of a substantial bioinformatics effort, difficulties in establishing the amount of environmental sample necessary for a good DNA extraction and the need for testing different genetic markers to obtain accurate results. 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 ‘metabarcoding’, 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 desenvolvimentos neste campo que foram apresentados na sessão especial (SE) “O uso de ferramentas moleculares na avaliação ecológica 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 aquáticos, 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, nomeadamente no uso de ‘metabarcoding’ para a deteção de biodiversidade críptica, estádios juvenis, espécies de reduzida abundância, espécies não nativas, do potencial de toxicidade e, finalmente, para a monitorização ecológica de diatomáceas e invertebrados. No entanto, dificuldades também foram assinaladas, que necessitarão de mais investimento futuro, e que incluem: lacunas taxonómicas das bibliotecas de referência (incluindo ao nível da espécie e da intra-variabilidade de espécies), ausência de bibliotecas públicas (por exemplo, para meiofauna), altos custos de sequenciação, a necessidade de um esforço substancial de bioinformática, dificuldades em estabelecer a quantidade de amostra ambiental necessária para uma boa extração de DNA e a necessidade de testar diferentes marcadores genéticos para obter resultados precisos

Advances in the use of molecular tools in ecological and biodiversity assessment of aquatic ecosystems

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 macroinvertebrate samples). Great advances were acknowledged inWe are grateful to all participants of the special session "The use of molecular tools in ecological and biodiversity assessment of aquatic ecosystems" for the productive discussions during the AIL 2018 meeting (XIX Iberian Association of Limnology meeting in Coimbra (Portugal, June 2018). M.J. Feio is supported by MARE strategic program (UID/MAR/04292/2013); SFP Almeida is supported by GeoBioTec strategic program UID/GEO/04035/2019. R. Cordeiro was supported by a Ph.D. Grant (M3.1.a/F/017/2011) from Fundo Regional da Ciencia e Tecnologia (FRCT); A.F. Filipe and A. Garcia-Raventos were supported by FRESHING Project "Next-generation biomonitoring: freshwater bioassessment and species conservation improved with metagenomics" funded by the Portuguese Foundation for Science and Technology (FCT) and COMPETE (PTDC/AAG-MAA/2261/2014 -POCI-01-0145-FEDER-356 016824); F.M.S. Martins was supported by a FCT PhD grant (SFRH/BD/104703/2014); A.R. Calapez was supported by a grant from the FCT-PhD programme FLUVIO (PD\BD\52510\2014); A.M. Pujante acknowledges the BIOWAT-KIT_E!11892 Eurostars project; Maria Fais and Sofia Duarte were supported, respectively, by a PhD (SFRH/BD/113547/2015) and a post-doc fellowship (SFRH/BPD/109842/2015), from FCT; and C. Murria acknowledges the Fundacio Aigues de Barcelona for funding his research