Periodic Reporting for period 4 - LeDNA (Global measure of biodiversity by understanding biogeochemical cycling of environmental DNA in lakes)
Okres sprawozdawczy: 2024-09-01 do 2025-02-28
The global loss and redistribution of biodiversity is a hallmark of the Anthropocene. Our challenge is to generate information about how altered biodiversity influences ecosystems and use this information to change our impact on the biosphere. To meet this challenge, we must know where species are, how their distributions change in time and why. However, current methods for determining species distributions is expensive, time intensive and hard to do for multiple species and large geographic regions- rendering global trend analysis near infeasible. We therefore need a paradigm shift. In this project we utilize the biotechnology of the fourth industrial revolution (i.e. inexpensive sequencing and computational power) to empirically change how we sample animal and plant biodiversity to solve the infeasibility problem of tracking multiple species distributions on large spatial scales. We tested if lakes act as accumulators of eDNA in the landscape by receiving transported eDNA from rivers. We investigated:
1. how chemical, physical, and biotic processes cause eDNA to decay and model its transport potential in the environment,
2. how much eDNA from a catchment is transported into a lake, and
3. in a global set of lakes, we tested whether eDNA measures biodiversity for large spatial scales.
If lakes accumulate eDNA from their catchments, sampling them will provide the paradigm shift needed to vastly change the cost, speed and geographic scale with which species can be surveyed through time to understand what effect their change has on the biosphere.
1. how chemical, physical, and biotic processes cause eDNA to decay and model its transport potential in the environment,
2. how much eDNA from a catchment is transported into a lake, and
3. in a global set of lakes, we tested whether eDNA measures biodiversity for large spatial scales.
If lakes accumulate eDNA from their catchments, sampling them will provide the paradigm shift needed to vastly change the cost, speed and geographic scale with which species can be surveyed through time to understand what effect their change has on the biosphere.
The LeDNA project developed a comprehensive framework to understand environmental DNA (eDNA) persistence and transport across different environmental states—cellular, membrane-bound, extracellular, and particle-bound. In vitro experiments with diverse species revealed that dissolved eDNA degrades fastest, while bacterial presence had minimal impact on degradation, challenging prior assumptions. Differences between plant and animal cells were negligible, though only dissolved DNA fit an exponential decay model. A novel study also revealed that microplastics may prolong eDNA stability by adsorbing DNA to their surfaces.
Fieldwork across eight lake catchments (237 samples) empirically separated eDNA into three states, showing that while dissolved and particle-bound eDNA have limited transport potential, membrane-bound DNA persists and can travel from streams into lakes—up to 40% of OTUs were shared upstream to downstream. Hydrological modelling of 217 inlets showed that eDNA reaches lakes within minutes to hours, although signals are less strong than expected, emphasizing the need to understand lake interface dynamics. Importantly, intracellular DNA is now confirmed as the most transportable state, with different states yielding unique biodiversity signals.
At the global scale, transport models indicated most of 1.4 million lakes could accumulate eDNA rapidly. A citizen science campaign sampled over 400 lakes across 121 ecoregions, covering over 6 million km². Initial analyses from 362 lakes detected over 87,000 OTUs, offering unprecedented biodiversity snapshots. Hypotheses about latitudinal diversity gradients are being tested, with early findings suggesting that DNA-based diversity patterns may differ from traditional expectations.
Technological innovations include a high-throughput qPCR multiplex system and a novel, patent-pending filtration device enabling global-scale, citizen-led biodiversity monitoring. Collectively, the project demonstrates how eDNA state separation, persistence studies, and transport modeling can transform biodiversity research and inform global conservation efforts under frameworks like the Kunming-Montreal Agreement.
Fieldwork across eight lake catchments (237 samples) empirically separated eDNA into three states, showing that while dissolved and particle-bound eDNA have limited transport potential, membrane-bound DNA persists and can travel from streams into lakes—up to 40% of OTUs were shared upstream to downstream. Hydrological modelling of 217 inlets showed that eDNA reaches lakes within minutes to hours, although signals are less strong than expected, emphasizing the need to understand lake interface dynamics. Importantly, intracellular DNA is now confirmed as the most transportable state, with different states yielding unique biodiversity signals.
At the global scale, transport models indicated most of 1.4 million lakes could accumulate eDNA rapidly. A citizen science campaign sampled over 400 lakes across 121 ecoregions, covering over 6 million km². Initial analyses from 362 lakes detected over 87,000 OTUs, offering unprecedented biodiversity snapshots. Hypotheses about latitudinal diversity gradients are being tested, with early findings suggesting that DNA-based diversity patterns may differ from traditional expectations.
Technological innovations include a high-throughput qPCR multiplex system and a novel, patent-pending filtration device enabling global-scale, citizen-led biodiversity monitoring. Collectively, the project demonstrates how eDNA state separation, persistence studies, and transport modeling can transform biodiversity research and inform global conservation efforts under frameworks like the Kunming-Montreal Agreement.
The major outcome of this project is a novel method for monitoring biodiversity on large spatial scales with a hand pump system that anyone can use. Additionally we invented a new way to sample eDNA from canopies of trees. In the short-term, the study of eDNA in lakes and their complete catchments, tested the limits of what could be spatially be inferred from transported eDNA and determined whether lakes act as accumulators in the landscape integrating biodiversity over large areas. While the results vary across Earths surface and further research is needed to determine the scale of sampling needed, we showed that lakes do receive transported eDNA from their catchments and that different states of eDNA do behave differently in natural waters. While lake water interface remains a challenge to study, we can say that measuring diversity at river inflows to a lake will represent diversity that is found in each rivers catchment, substantially changing the scale of sampling a needed to measure diversity on larger spatial scales that can be used for estimating regional animal and plant biodiversity. The lake survey throughout the world demonstrated the participatory power of eDNA sampling to facilitate collection of biodiversity information on large spatial scales and produce the first map with estimates of animal and plant biodiversity for terrestrial and aquatic across latitudes and ecoregions of the world based on an environmental DNA survey.