Source: GNS Science
A team of scientists from GNS Science, the Cawthron Institute and Otago University will this week start taking samples from some of the country’s most southern and high-altitude lakes.
The sampling is part of a nationwide project called ‘Our lakes’ health – past, present, future’ which aims to determine the health, wellness and history of New Zealand’s 3,800 lakes.
The team will analyse samples from about 300 lakes, which will provide vital clues to the health of the lakes over the past 1000 years.
“Lake sediments are natural archives that continuously record environmental history, providing measures of current and historical aquatic communities and water quality,” says co-project leader Marcus Vandergoes from GNS Science.
We’ll sample seven lakes around Queenstown which are all above the treeline, using a range of new methods such as environmental DNA and scanning techniques to study these globally distinct lakes
“We take sediment cores from the deepest part of the lakes, and the data collected from the sediment is equivalent to a millennium of monitoring.“
The team will spend two weeks sampling a range of lakes, including the team’s highest lake to date: Lake Alta at 1800 m in The Remarkables above Queenstown.
Co-programme leader and freshwater scientist Susie Wood from the Cawthron Institute is particularly excited about the high alpine lakes.
“New Zealand has over 600 alpine lakes and we know next to nothing about them – or the animals and plants that live in them.
“We’ll sample seven lakes around Queenstown which are all above the treeline, using a range of new methods such as environmental DNA and scanning techniques to study these globally distinct lakes.”
The alpine lakes are also critical for exploring the impact of climate change, according to Chris Moy from University of Otago.
“Because most of New Zealand’s alpine lakes have not been impacted by factors such as land-use change or the introduction of non-native species, these systems are the ideal place to explore how past climate shifts have impacted lake ecosystems,” Dr Moy says.
The team has been sampling lakes across New Zealand for just over 12 months, so we’re really excited to hit 200!
The project utilises cutting edge research equipment operated by Otago University. This includes an Itrax core scanner which enables the chemical composition of the sediment cores to be very rapidly characterised. This will provide exciting new insights into the how water quality and the land around the lakes has changed.
The project also uses a unique type of lake sediment corer, a Mackereth corer operated by Sean Fitzsimons from the University of Otago, which is integral for sampling the deep lakes in New Zealand.
The team have consulted with Ngai Tahu about the sampling process and timetable, and are now engaging with a group of rangatahi working on an environmental monitoring scheme, Te Nohoaka o Tukiauau.
During this field campaign the team will reach a significant milestone, sampling their 200th lake.
“The team has been sampling lakes across New Zealand for just over 12 months, so we’re really excited to hit 200!”, Dr Vandergoes says.
“We are generating some really exciting results which are highlighting differences in how lake health has changed across New Zealand.”
For more information please visit the project website: https://lakes380.com