What is eDNA?
Environmental DNA and RNA (eDNA) is the genetic material organisms leave behind in their environment, including in water.
Water is essential for all life and holds valuable information about the health of our communities and the environment. Modern methods have been developed to monitor water more holistically, including detecting multiple pathogens and evaluating ecosystem health using eDNA (and eRNA) sequencing. eDNA monitoring offers a non-invasive, cost-effective, and rapid method to assess population health, agricultural health, and ecosystem health – informing decision-making for supporting health for communities, individuals, public health and industries, at both regional and national scales.
How Does eDNA Surveillance Work?
eDNA for Wastewater Monitoring
Wastewater based surveillance (WBS) has been implemented in many communities across Canada and around the world to track disease-causing organisms (pathogens). When people who are sick use the washroom, their waste is carried through the sewer system to a wastewater treatment facility. Samples taken from the sewer/facility are then analyzed to determine which pathogens are present and how abundant they are. WBS is transformative in that it is more rapid and cost-effective, plus it enables surveillance of entire communities/areas more inclusively (e.g. surveying those with and without access to a doctor). It also enables earlier detection of certain pathogens – providing more lead time to respond. WBS has further been used to detect important trends in pathogens gaining resistance to the drugs used to treat infections. Collectively, such environmental sequence-based monitoring is a revolutionary technology that can cost-effectively and inclusively enable Learning from Water, directly saving lives, and can be initiated within a community, providing a more wholistic view of disease that complements more limited, biased case-based testing.
A wastewater treatment facility. Image credit: Cleantech Water
eDNA for Biodiversity and Climate Change Monitoring
A melting glacier. Image credit: David Suzuki Foundation
Human activities are leading to accelerating climate change around the world. Climate change results in extreme weather, forest fires, fluctuating temperatures, drought and melting permafrost, which all impact the interconnected life that our environment supports – challenging food production, impacting persistence of disease, and changing ecosystems including non-native and invasive species. eDNA monitoring can help us monitor our current situation by cataloging the biodiversity that currently exists and predicting how it can change in the coming years and decades. For many Indigenous communities, it can also provide important information about where species that are important as their food sources are now located. In mining, monitoring an environment before and after mining activity can help ensure land is returning back to its natural state before mining occurred. This collective information can be used to inform conservation strategies, plan environmental remediation, and inform approaches to ensure food security – both nationally and more locally.
eDNA for One Health / One Ecosystem Health
One Health is an approach that recognizes that the health of humans, animals and ecosystems are interconnected and rely on each other. This approach encourages cross-collaboration between physicians, veterinarians, public health entities, those engaged in food production & animal husbandry and any groups whose activities might influence the interconnected web of life on our planet. One Health takes an integrated approach to disease control and health threats such as growing resistance of pathogens to antibiotics (antimicrobial resistance; AMR) and pathogens that can impact a wider variety of animals (for example, bird flu / avian influenza H5N1). The integrated One Health – or even One Ecosystem – approach recognizes that addressing challenges in an integrated fashion (such as tackling AMR impacting both the agri-foods industry and people) is needed for optimal results. This can also have significant economic impacts, as for example AMR incurs tremendous healthcare costs (~$1.4 billion/year in Canada, and by 2050 costing is estimated to exceed $100 trillion in lost productivity globally – not including impacts on food production failure. eDNA monitoring can help to track threats (such as AMR and bird flu) by enabling cost-effective, rapid monitoring of many different physical environments simultaneously. This allows scientists to determine where the sources of health threats might lie, and how they are moving through different animal species, humans, and locations. Such information can inform decision making to help reduce spread of disease and foster holistic practices that promote health.
A One Health approach recognizes the interdependence of all life and the environment. Image credit: Minimizing AMR Mission