A New Era of Biodiversity Monitoring: eDNA technology and its applications for conservation

In a world of rapidly changing biodiversity and climate conditions, characterised by irreparable damage and fundamental changes to key marine, terrestrial, and freshwater ecosystems, there is a pressing need to overhaul conventional biodiversity monitoring systems. We urgently require rich, accurate data if we’re to halt and reverse biodiversity loss and hit nature restoration targets. Conventional systems are resource-intensive, difficult to scale, and often produce large gaps in key data sets as hard-to-detect species evade conventional monitoring. These data gaps can lead to an over-reliance on ‘indicator species' as proxies for measuring ecosystem health.

Whilst the use of indicator species is an effective response to the limitations posed by conventional monitoring, new technologies mean there is no need to be limited. Earth observation has been posed as a solution to the problems of cost and scale, but for detailed species level insight - a crucial requirement for high-integrity projects - environmental DNA technology has become the gold standard.

What is eDNA?

All life on earth – from bacteria and fungi to blue whales – leave tiny traces of DNA in the environment. eDNA technology allows us to sample the environment - soil, water, or air - for these fragments of DNA to reveal a comprehensive picture of the biodiversity of that ecosystem. It has a wide range of applicability, already helping businesses and organisations belonging to a wide range of sectors.

Samples can also be collected by non-experts. Academic institutions and conservation groups have leveraged citizen scientists to scale monitoring efforts in a range of habitats, from UK rivers to Colombian rainforests.This enhances the technology’s accessibility and scalability, increasing the reach of surveying organisations and keeping costs down.

Broadly, there are two types of eDNA surveying. Firstly, users can test for specific species. Common examples of this in the UK would be monitoring for great crested newts, european eels and signal crayfish. The other type of test is metabarcoding, which tests for multiple species in a single sample. This establishes comprehensive biological baselines from which changes in biodiversity, good and bad, can be detected; they become the yardstick by which the success of a project is measured.

For example, fungi to bacteria could be surveyed on sites set for woodland creation or on a farm looking to implement regenerative practices. An increase in the ratio of fungal functional diversity vs. bacterial functional diversity would indicate an increase in soil health.

The earlier that a baseline occurs in a project, the better, as longer time periods provide higher integrity data. eDNA provides very robust baselines, particularly compared with conventional biodiversity monitoring techniques, whilst also being scalable, affordable and easily repeatable.

How can eDNA help the conservation sector?

For the conservation sector, the data that is accrued through eDNA surveying has a wide range of applications, including detecting elusive, invasive, or endangered species of interest. For instance, recent eDNA surveying undertaken in Somerset led to the alarming finding that eels had vanished from the area, despite consistent historical abundance, and action has now begun to reintroduce and protect eels in the region. Overseas, eDNA has been used to boost conservation efforts of critically endangered pygmy hippos and Amazon river dolphins, as well as to slow the spread of the invasive zebra mussel, which is hugely damaging to habitats and infrastructure, which is strong supporting evidence of the unique capabilities of the technology.

eDNA data can also be used to inform biodiversity offsetting and habitat creation projects. Nature is incredibly complex, and far more so than the climate - particularly as there is no equivalent to CO2 in nature. Therefore, effectively mitigating and offsetting biodiversity harm is difficult. However, the comprehensive results and insights produced by eDNA surveys can be crucial to increasing the integrity of habitat creation and restoration projects. A good example is the work undertaken by the engineering firm Jacobs, who used soil-based eDNA surveying to identify almost 3,000 species. Using this data, they were then able to visualise the difference in soil biodiversity between grassland and woodland habitats at their site, enabling them to characterise the ‘gap’ that needed to be bridged through habitat creation.

How are NatureMetrics enabling conservation efforts?

At NatureMetrics, much of our work is related to these applications, with many of our customers in the conservation space having incorporated eDNA into their operations to positive effect. For example, a recent project undertaken by Forestry England in partnership with Forest Research involved the eDNA analysis of samples of both the soil and the forest canopy in North Yorkshire’s forests. It yielded some incredible results, detecting more than 2,400 fungal sequences and more than 200 species of invertebrates. The traps in the canopies and in shrub layers also identified over 300 different arthropods.

These findings, Forestry England believe, could represent the start of a shift towards a whole new system of forest biodiversity monitoring, characterised by free data-sharing between conservation projects. This would lead to an improvement in our collective understanding of the biodiversity of the nation’s forests, and the changes they will be going through as a result of climate change, helping conservation groups to improve their forest management techniques.

Dr Andrew Stringer, Head of Environment for Forestry England explained “It's mind-blowing. The volume of data means we are no longer looking at a handful of "indicator species", such as birds and butterflies, to understand woodland biodiversity, but whole communities. This means we could begin to robustly monitor entire woodland ecosystems. It feels a bit like looking through a microscope for the first time to a whole new world of detail.”

Ushering in a new era

eDNA offers a truly transformative solution to the urgent biodiversity monitoring problems that continue to prevent sufficiently meaningful progress in the pursuit of nature positive. Though flawed, the sentiment ‘you can’t improve what you can’t measure’ still holds sway in many quarters and eDNA is helping break down these artificial barriers by radically increasing what we can measure and how well we can measure it.

Katie Cruickshanks, UK Conservation and Rewilding Business Development Manager, and Ecologist at NatureMetrics.

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