No abstract

This protocol was established for the Nordic Blue Carbon Project (2017–2020) for tracking the presence of kelp DNA in marine sediments, providing preliminary quantitative information on the original kelp biomass. Nordic blue forests are coastal vegetated habitats, such as kelp forests, eelgrass meadows and rockweed beds, that are important natural sinks for carbon and thereby climate regulation. They also play an important role in climate adaptation. Simultaneously, blue forests are at high risk from climate change and other human impacts, such as eutrophication and coastal development. The advent of eDNA methods for tracking animal or vegetal organisms in water or sediment matrices, has enabled not only geographical detection without collection of the organism but also temporal study of their presence in dated sediment cores. The fate of eDNA and its persistence in the environment is intimately related to its biophysical surroundings. eDNA entrapped in sediments may be preserved on long time scales, up to centuries, enabling historical tracking of the presence of a species on a site. The present protocol was developed for tracking eDNA of a predominant Norwegian kelp species, Laminaria hyperborea, in dated marine sediment cores. This approach enables confirmation of species specific contribution to carbon sequestration in an effort to evaluate marine sediments operating as carbon sinks. This work was financed by the Norwegian Environment Agency (Miljødirektoratet) contract #17080044 and published in a NIVA report ISBN 978-82-577-7384-7, Norwegian Environment Agency Report M-2090|2021, Blue Carbon eDNA – A novel eDNA method to trace macroalgae carbon in marine sediments. .