The health of many of our lakes is deteriorating, yet our ability to make informed assessments at a national scale is hampered by a paucity of critical knowledge. Of the 3,800 lakes greater than one hectare in New Zealand, we have knowledge on lake health for fewer than 5%.
A simple fix might be to initiate more monitoring programmes. However, this costly process only focuses on present and future conditions and would not necessarily tell us how or why deterioration has occurred. In order to tailor successful restoration programmes, we need to know what drivers are behind the historical and current environmental conditions of each lake.
The solution can be found in the lakes sediments. Laid down year upon year, sediments preserve indicators of lake life and water quality, equivalent to centuries of monitoring. These natural archives can provide the deeper understanding we seek to properly restore the vitality of our lakes.
This project will characterise the health of our lakes by uncovering their environmental history from sediment cores taken from 380 lakes. We will use a combination of traditional environmental reconstruction techniques and more recent methods such as environmental DNA and high resolution core scanning. Our data will allow us to characterise current lake health and explore rates and causes of change over the last 1000 years.
Working with iwi and hapū, we will learn from their mātauranga and oral histories that draw upon long associations of tangata whenua interactions with lakes. This knowledge sharing will help to enrich and inform our joint aspirations for environmental reconstructions. The knowledge from this project will be used to assess water quality, characterise biodiversity and inform and prioritise mitigation strategies, on a national scale.