Prof. Susie Wood1, Dr John Pearman, Prof Marcus Vandergoes, Prof Jamie Howarth, Dr Georgia Thomson-Laing
1Lincoln University, , New Zealand
Biography:
Susie is a Professor at Lincoln University and co-director of Waterways Centre in Canterbury, Aotearoa New Zealand. Her research focuses on understanding toxic cyanobacteria dynamics in freshwater systems, developing molecular techniques to monitor aquatic ecosystems, and integrating cutting-edge techniques with traditional paleolimnological approaches. She has more than 250 peer-reviewed scientific publications and attracts funding from the New Zealand government and various tiers of government and industry for collaborative funding for a range of water quality issues. She received the Kilham Lecture Award from the International Limnology Society in 2022, and the New Zealand Freshwater Sciences Society medal in 2019.
Abstract:
Aotearoa New Zealand provides a unique natural laboratory for investigating long-term drivers of lake ecosystem change. The arrival of Māori approximately 750 years ago established a relatively recent anthropogenic baseline, marked by forest clearance through burning, landscape modification, and the introduction of mammalian predators. European settlement from the early 1800s further transformed catchments through widespread vegetation loss, agricultural development, species introductions, and, by the early twentieth century, intensified farming practices and phosphate fertilizer use. Here, we apply sedimentary ancient DNA (sedaDNA) analysis to approximately 100 lake sediment cores spanning the last century to reconstruct ecological change across a broad gradient of lake types and catchments. Multi-gene metabarcoding was undertaken on a subset of lakes using markers targeting bacteria (16S rRNA), eukaryotes (18S rRNA, COI), plants (trnL, rbcL), and vertebrates (12S rRNA), enabling integrated assessment of biodiversity responses across multiple trophic levels. Using selected case-study lakes, we evaluate how biological communities respond to both short-term natural disturbances, including extreme climate events, earthquakes, and volcanic eruptions, and longer-term anthropogenic pressures such as land-use change and agricultural intensification. Comparisons across lakes reveal differing trajectories of ecological resilience, recovery, and transformation. This study highlights both the opportunities and challenges of applying sedaDNA approaches across large spatial scales, including issues of taxonomic resolution, preservation, and comparability among sites. By integrating multi-trophic records from numerous lakes, we demonstrate the potential of sedaDNA to improve understanding of ecosystem responses to environmental change and inform future lake management and restoration efforts.