Cover Image

Cover Illustrations: (Right to left): (Image 1): Salmon farm in Norway; (Image 2): Urdaibai estuary and Sukarrieta in Bizkaia, Basque Country, from Atxarre; (Image 3): eDNA metabarcoding is a powerful tool for marine biosecurity surveillance and for environmental biomonitoring to inform management and conservation decisions; (Image 4): eDNA sampling around oil drilling platform in the North Sea; (Image 5): Research vessel Electra in Tvärminne, Finland; (Image 6): Sediment coring and subsampling from Friedrichshafen, Lake Constance, Germany; (Image 7): Researchers ‘counted’ Japanese jack mackerel in Maizuru Bay, Japan, through quantitative measurements of environmental DNA concentration; (Image 8): Brook Trout from lake in Kootenay National park; (Image 9): A lake trout looks out from the shore of Lake 224 after recovering from surgery during which an acoustic telemetry transmitter was implanted in its abdominal cavity. The movements of this lake trout will be monitored continuously for 3.5 years; (Image 10): eDNA sampling in a lentic water; (Image 11): Environmental DNA will improve detection of the elusive threatened species, Australian Grayling (Prototroctes maraena); (Image 12): Retrieval of the Continuous Plankton Recorder on the RSV Aurora Australis to collect zooplankton in the Southern Ocean and to compare traditional biodiversity survey methods to eDNA metabarcoding of small seawater samples, 2018; (Image 13): A net pen salmon farm in British Columbia; (Image 14): Sciaphilous benthic community sampled in Cabrera Island; (Image 15): The mayfly Serratella ignita is a key bioindicator of freshwater quality. the quality. Ficetola et al. developed a exasustive database with the barcodes of European freswhater benthic fauna, and evaluated the markers most appropriate to assess the freswhater quality using environmental DNA; (Image 16): The performance and efficiency for biological assessment and monitoring of DNA metabarcoding of ethanol used to preserve freshwater macroinvertebrate samples still requires validation and optimization. Here we show that while metabarcoding markers from three genomic regions (CO1, 18S and 16S) consistently detect the target taxa in silico, they often fail to detect the same taxa in mock and real samples. Through modelling, we show that low probabilities of detection are associated with taxa with low proportional abundance and high body armouring, after controlling for variation in sample read coverage; (Image 17): A crucian carp (Carassius carassius) individual caught by fyke nets in one of the Norfolk study ponds; (Image 18): DNA metabarcoding from sample to species identification; (Image 19): Specimen of Scinax pinima found during environmental DNA sampling. This species was last seen in 1987; (Image 20): Tiger leech, Haemadipsa picta, used for iDNA monitoring of mammals in Sabah, Borneo (RD); (Image 21): Environmental DNA is revolutionizing the monitoring of remote areas, such as the foreland of the Tiedemann Glacier in Canada (in the picture). Monitoring these areas with eDNA implicates that samples are to be preserved for a certain time. Our study evaluates how multiple approaches to the preservation of soil samples influence biodiversity analyses performed through eDNA metabarcoding, and provide guidelines for the choice of methods for soil sample preservation method; (Image 22): The photography depicts a study site in the catchment of the river Thur, Switzerland; (Image 23): Use of environmental DNA in water samples enabled rapid, efficient, multi‐year monitoring of endangered tidewater goby across its entire geographic range along 1350 KM of the California coast; (Image 24): Anchovy swarm in the kelp forest, Monterey Bay Aquarium, California; (Image 25): Aphodius spp. on cow dung, Denmark. Photo Credit: (Image 1): Tristan Cordier; (Image 2): Photographer unknown (©AZTI); (Image 3): WERNERWERKE GbR, Berlin and Thorsten Stoeck, Technische Universität Kaiserslautern; (Image 4): Jesper Goodley Dannisøe; (Image 5): Elias Broman; (Image 6): Anan Ibrahim; (Image 7): Reiji Masuda, Kyoto University; (Image 8): Dylan J. Fraser; (Image 9): IISD Experimental Lakes Area; (Image 10): Rein Brys; (Image 11): Tarmo A. Raadik; (Image 12): Bruce E. Deagle © Australian Antarctic Division; (Image 13): Scott R. Gilmore; (Image 14): Xavier Turon; (Image 15): Philippe Usseglioi‐Polatera; P. Wagner;(Image 16): Filipa M.S. Martins; (Image 17): John Bailey; (Image 18): Aline Joustra; (Image 19): Célio Haddad; (Image 20): Rosie Drinkwater; (Image 21): Gentile Francesco Ficetola; (Image 22): Elvira Mächler; (Image 23): Map data ©2021 Imagery ©2021 NASA, TerraMetrics; (Image 24): Peter Shum; (Image 25): Morten D. D. Hansen.