Detection of a marine to terrestrial transition in lake sediment from Baffin Island, Arctic Canada, using sedimentary DNA

Mr Matthew Power1, Dr Sarah E. Crump2, Dr Mahsa  Mousavi-Derazmahalleh1, Professor Gifford H. Miller3, Professor Michael Bunce1, Professor Morten Allentoft1,4

1Curtin University, , Australia, 2University of California Santa Cruz, , United States of America, 3University of Colorado Boulder, , United States of America, 4University of Copenhagen, , Denmark

Abstract:

The recent development and refinement of the molecular toolkit to detect ancient DNA in sediment samples (sedaDNA) has allowed the high-resolution reconstruction of ancient ecological communities dating back thousands of years. Specifically, DNA from lake sediment has been used to derive continuous records of ecological community changes through variable paleoenvironmental conditions. These paleoecological reconstructions can be an important tool for understanding how ecosystems may respond to current and future warming, but reliable methods for taxonomic detection are needed in order make optimal use of these bioarchives. In this study, metabarcoding assays targeting mammals, birds, diatoms, and marine fauna have been carried out across a sediment core collected from Lake Qaupat, Baffin Island, Arctic Canada. While Lake Qaupat is currently ~30 m above sea level, it is located below the local marine limit related to isostatic adjustment after deglaciation. Consequently, initial sediment accumulation was in a marine environment. Combined results from the DNA assays indicate a transitional period around 6,000 years ago, during which marine-based fauna are systematically replaced by more terrestrial-based fauna. This research builds on previous studies to develop Baffin Island paleorecords in an effort to inform future changes to the Arctic system in the context of a rapidly warming world. Ultimately, these data showcase the power of sedaDNA to document dramatic ecosystem changes, with implications for ecological responses to future sea level change.


Biography:

Matt has worked as a research technician across New Zealand, Sweden and Australia for over 16 years. Since joining the Trend Laboratory at Curtin University in 2014, he has been involved in wide range of research projects utilising metabarcoding techniques, most notably analysis of complementary and alternative medicines, dietary analysis and biodiversity surveys of terrestrial and marine species and analysis of past floral distributions using sedimentary ancient DNA.

Matt is currently a Masters student using sedimentary ancient DNA collected from Arctic sediment cores to investigate past faunal distributions.

Date

Mar 21 - 23 2022
Expired!