Georgia Thomson-Laing1
1Cawthron Institute, Aotearoa / New Zealand
Biography:
Georgia Thomson-Laing is an early-career researcher and molecular ecologist at Cawthron Institute in Nelson, Aotearoa New Zealand. Her research uses environmental DNA (eDNA) to understand lake ecosystems and how taonga species, including native fish, and biological communities respond to environmental change. Georgia completed a Master’s researching eel reproductive biology at the University of Otago in 2017 and a PhD at Victoria University of Wellington in 2024, using sedimentary eDNA to investigate historical changes in native fish communities. She is currently part of the Our Lakes Our Future research team and holds a Marsden Fast-Start grant investigating the extinct New Zealand grayling.
Abstract:
Lakes are sentinels of environmental change, recording the effects of natural and anthropogenic pressures on freshwater ecosystems. Many lakes in Aotearoa New Zealand are undergoing rapid ecological change, making it increasingly important to understand how biodiversity responds to these pressures. Environmental DNA (eDNA) has emerged as a powerful tool for tracking biodiversity. However, translating eDNA data into ecological insights requires an understanding of how sampling design, spatial heterogeneity, species ecology, and environmental conditions influence species detection and community patterns. Our research combines contemporary eDNA surveys with sedimentary DNA (sedDNA) and paleolimnological approaches to investigate freshwater ecosystem change across timescales. Contemporary studies focus on improving the application of eDNA in lake ecosystems to ensure biodiversity assessments accurately represent present-day communities. These insights provide a foundation for extending DNA-based approaches into the past. Lake sediments preserve biological and environmental archives spanning decades to millennia, allowing the reconstruction of historical communities and ecosystem trajectories. By integrating sedDNA with other paleolimnological indicators, we investigate biological responses to major environmental pressures, including non-native fish introductions, agricultural intensification, and extreme weather events. In this presentation, I will highlight how eDNA can move beyond a contemporary biodiversity snapshot to reveal long-term patterns of ecological change, resilience, and recovery.