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All organisms leave traces of their DNA in the environment they live in. This environmental DNA (eDNA) can be used to detect and monitor single species as well as communities, and potentially be utilized in early warning systems to detect alien species. In this report, we give an overview of eDNA-based methods used to detect and monitor alien species, and give examples of speciesspecific assays designed to identify species that are alien to Norwegian nature or have the potential to establish viable populations in Norway (doorknockers). We emphasize the need for several stages of testing before species-specific assays can be operational, and discuss the importance of including models to assess detection probabilities. Going through standards for sampling and analyses, we suggest a number of minimum requirements for eDNA sampling, laboratory practice, bioinformatics and the use of reference libraries, as well as for reporting results from eDNA studies. The origin and fate of eDNA in different environments can influence its usefulness in detecting and monitoring alien species. We outline factors for terrestrial, freshwater and marine ecosystems and provide examples from six case studies where eDNA has been used to detect and/or monitor alien invasive species: invertebrates and vascular plants in soil of imported ornamental plants, freshwater crayfish and crayfish plague, Gyrodactylus salaris, pink salmon, Canadian pondweed, and American lobster. We provide a decision diagram for detection and monitoring of invasive species starting with early considerations for implementation of a monitoring program, and ending with management decision points depending on detection outcomes at different stages. Finally, we provide some key recommendations for the use of eDNA in assessments of alien and doorknocker species. Bruk av miljø-DNA og DNA-baserte metoder for å vurdere og overvåke fremmede arter og dørstokkarter. The use of eDNA and DNA-based methods to assess and monitor alien and doorknocker species

We set sail from Longyearbyen on 30.6.2021 to collect surface sediments, long sediment archives, water and plankton samples. The study area is located north of Svalbard, within the seasonal and permanent sea ice covered Arctic Ocean. We took stations N of Svalbard, near Nordaustlandet, Sophia Basin, Yermak Plateau and on the shelf east of Svalbard. In total, we had 52 stations. We deployed the multicorer at least once at every station and sampled the core tops already onboard. These samples will be included in the Arctic Surface Sediment DNA Database, which we will use to establish new aDNA based sea ice proxies. We recovered gravity cores from 12 stations that can be used to reconstruct the Arctic sea ice history in the Holocene, last glacial and likely also Last Interglacial. We collected ice and water and filtered these for eDNA and biomarkers, and water for tracing the isotope signal of the different water masses in the region (Atlantic Water, Polar Water). publishedVersion

Despite their importance in shaping the structure and function of marine microbial food webs, little is known about factors regulating marine virus abundance. Previous work demonstrated clearance of laboratory-cultured Emiliania huxleyi virus by the appendicularian Oikopleura dioica; however, the applicability of this interaction to natural virus assemblages was not investigated. Here, we conducted controlled laboratory experiments using O. dioica and mesocosm water containing natural virus assemblages with high densities of virus, and measured removal of virus by O. dioica using both flow cytometry and molecular methods. Bayesian models based on flow cytometry quantification of virus particles demonstrated efficient removal of viruses (mean 90.3 mL ind−1 d−1), with a clearance efficiency of 42.6% relative to food algae. Molecular detection of virus removal by quantification of viral mcp gene copies revealed a mean clearance rate of 68.1 mL ind−1 d−1. Fecal pellets from these experiments demonstrated that viruses in fecal pellets retain infectivity despite passage through the O. dioica gut. Shotgun metavirome analysis demonstrated O. dioica removal of large virus groups, notably the Phycodnaviridae. The results demonstrate the removal of E. huxleyi virus from natural virus assemblages by O. dioica and the maintenance of viral infectivity when incorporated into fecal pellets, prompting further investigation on the fate of fecal-packaged viruses and their impact on host dynamics. Furthermore, our results indicate the generality of this interaction for other large algal viruses, raising questions about the implications of this mechanism of marine virus redistribution on the broader marine virus community. publishedVersion

MetaMon (2018-2021) was a project at the NORCE Molecular Ecology Research Group aimed at maturing eDNA for sediment offshore environmental monitoring. Findings include (i) guidelines for sampling and processing, (ii) a 97 station metabarcoding study showing metabarcoding de novo biotic indices performed comparable to the morpho-taxonomic NSI index and co-occurrence networks for impacted and non-impacted sites. Two ddPCR assays were developed and tested as a proof of concept. Finally, (iii) a gap analysis was done for online databases, (iv) several species were individually sequenced, and (v) COI metabarcoding of bulk animal tissue evaluated. With these deliverables together with an ambitious program for communication and outreach MetaMon has significantly advanced progress towards use of metabarcoding data in offshore environmental monitoring, yet findings need to be consolidated with further data and time series validation.

Source at https://www.miljodirektoratet.no/publikasjoner/2021/juni-2021/kunnskapsstatus-for-bruk-av-molekylare-verktoy-i-kartlegging-og-overvakning-av-biologisk-mangfold-i-marine-miljo/ Denne rapporten er bestilt av Miljødirektoratet fra NorBOL (Norwegian Barcode of Life), et nasjonalt nettverk av forskningsinstitusjoner som koordineres av NTNU Vitenskapsmuseet. Universitetsmuseet i Bergen har hatt prosjektledelsen. Rapporten gir en oppsummering av dagens status på DNA-basert metodikk som verktøy i kartlegging og overvåking av biologisk mangfold i det marine miljø. Fokus har vært på innsamlingsmetodikk og protokoller for DNA-analyser av arter og artsgrupper. Metodikken er evaluert opp mot kartleggings- og overvåkingsaktivitet i regi av Miljødirektoratet, og kommer med anbefalinger for videre framdrift for å ta metodikken i bruk i nasjonal kartlegging og overvåking. Rapporten har også en gjennomgang og evaluering av eksisterende referansemateriale og referansesekvenser for relevante arter og artsgrupper som inngår i Miljødirektoratets kartleggings- og overvåkingsaktivitet.