Kitty McKnight, Dr Kathryn Korbel1, Prof Grant Hose
1Macquarie University, Sydney, Australia
Biography:
Kitty has a background in aquatic ecotoxicology and risk assessment, with experience working on a range of industry and research projects. More recently she has been working in a freshwater ecology team, focusing on groundwater ecosystems. She works on team projects including ecological risk assessments, ecosystem health monitoring, and studies on natural and human-induced changes to groundwater ecosystems.
In 2024, she completed a Master of Research investigating the effects of groundwater extraction on groundwater biota and chemistry. Currently, Kitty is pursuing a PhD investigating the spatiotemporal variability of groundwater ecosystems across New South Wales, Australia, with a focus on groundwater ecological communities.
Abstract:
Groundwater is an important resource in arid and semi-arid areas, where it sustains groundwater dependent ecosystems and can be the primary source of water for human use. Shallow alluvial aquifers are often highly connected to surface waters and are influenced by recharge events and groundwater extraction. Changes to groundwater levels, often induced by extraction, can impact groundwater chemistry and alter hydrology, however our understanding of the impacts of water level change on biota is largely unknown.
To understand the impacts of prolonged groundwater extraction on groundwater levels and ecosystems, a 28-day pumping experiment was undertaken in a shallow alluvial aquifer in Maules Creek, NSW. Groundwater samples (eDNA, stygofauna and water chemistry) were collected from 13 bores in impacted and reference locations before and immediately after the pump experiment, and throughout a three-month recovery period post pumping. Traditional sampling methods were combined with eDNA methods to give a more complete view of the biological community within the region. Although the planned experiment was impacted by major flooding during the pumping phase, this presented opportunities to investigate the impact of recharge events in combination with abstraction. Results demonstrated temporal differences in groundwater biological communities, with water chemistry indicating potential recharge events. Biological communities, particularly fungi and stygofauna, also displayed differences that could be attributed to both extraction and recharge events. Results indicate the potential impacts that changes to water levels can have on groundwater ecosystems and can aid our understanding and management of this resource.