CRI Scientists Are Using Environmental DNA to Study Wetlands in Grand Lake Meadows
Wetlands are a precious resource for Canadians, threatened by encroachment from development and society’s ever-increasing demands for water. Scientists at the Canadian Rivers Institute are working to improve our knowledge around wetlands protection by carrying out an ambitious study on one of New Brunswick’s most threatened wetlands - the Grand Lake Meadows area of the lower Saint John River. Dr Donald Baird and Dr Wendy Monk of Environment and Climate Change Canada, located in the Biology Department at the University of New Brunswick in Fredericton and their team are using cutting-edge ecological survey methods, linking aerial observations of wetland extent to ground-level experiments to measure how critical wetland ecosystem functions including organic matter processing vary across a gradient of human activity. Their aim is to understand the role played by biodiversity - the variety of animals, plants and micro-organisms which live in an area - in sustaining key wetland functions which support the many rare and endangered species which inhabit the Grand Lake Meadows and the adjacent Portobello Creek National Wildlife Area.
The Saint John river floodplain is one of the few largely intact large river floodplains on either side of the Atlantic Ocean, and is an area rich in biodiversity. (Photo: Natalie Rideout).
Using internationally-groundbreaking techniques developed in collaboration with Dr Mehrdad Hajibabaei’s lab at the University of Guelph, samples collected from wetland habitats are being used to provide a map of biodiversity and ecosystem function at an unprecedented level of detail. “Many people will be familiar with the use of BioBlitz methods for rapid survey of conservation areas,” says Dr Baird “but although these allow rapid collection of specimens, it may take years or even decades to complete necessary identifications. These new environmental DNA techniques allow us to extract DNA from routine environmental samples of water or sediment. This extract potentially contains the DNA sequences of all organisms living in an area - and once analysed, provides researchers with immediate access to a list of the organisms present at a site. This new 'made-in-Canada' technique is revolutionising environmental monitoring, and will allow us to rapidly assess river and wetland ecosystems to better understand the consequences of development.
Silver maple, seen here at the Portobello Creek National Wildlife Area, contribute leaf litter which provides a critical energy source sustaining aquatic foodwebs in the Saint John River floodplain (photo: Natalie Rideout).
Dr Baird’s student, Natalie Rideout is using these techniques to study how long-term change in Grand Lake wetlands is associated with historical development in the area, including the construction and operation of dams in the upper Saint John watershed, and the building of an elevated highway which traverses the wetland. She is examining the role played by a key floodplain species - the silver maple - in providing a food source for the base of the food web which sustains fish and wildlife habitat. She is also studying the importance of functional diversity - the variety of ecological roles present in the invertebrate community, and how this is linked to biodiversity.
CRI MSc student Natalie Rideout with an array of leaf decomposition packs ready to deploy at a Grand Lake Meadows wetland site. (Photo: Kristie Heard)
Also part of the team studying Grand Lake Meadows this summer are two European science exchange students: Renske Anema from the Netherlands, and Sonia Stefani from Germany.
CRI summer intern Renske Anema making friends with a local at a Grand Lake Meadows study site. (Photo: Natalie Rideout)
Zoe O'Malley, Dr Monk's student, is comparing these new genomic techniques with traditional sample methods to try and identify critical habitat characteristics for a local insect species-at-risk and the broader insect predator community. Through these studies, the CRI is highlighting the important role played by wetland conservation areas in the Lower Saint John River, which are of national and international significance in terms of species conservation. By studying the entire ecosystem, we gain new perspectives on the connectedness of plants, invertebrates and wildlife, helping us to sustain key species valued by society, and preserving the natural beauty of wetlands for future generations.
The work described in this article has received support from the the University of New Brunswick (Grand Lake Meadows Fund), the Province of New Brunswick (Wildlife Trust Fund, Environmental Trust Fund) and from Environment and Climate Change Canada. This work is also associated with the Mactaquac Aquatic Ecosystem Study (MAES), funded through a Collaborative Research and Development Grant from the Natural Sciences and Engineering Research Council of Canada.
For more information, contact: Dr Donald Baird, Environment and Climate Change Canada / Canadian Rivers Institute (firstname.lastname@example.org).