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eDNA: The new science behind measuring biodiversity

Biodiversity is the living pulse of our planet, from the smallest microorganism to the giants of the African savannah.

It underpins the delicate balance of countless ecosystems, which are vital for both human survival and nature on a wider scale. 

ICMM members have pledged to help create a nature positive future. But to do this, they must be able to measure their effect on the environment and biodiversity. 

Environmental DNA is an innovative tool for understanding biodiversity within local environments and ecosystems. Scientists analyse water samples from sites of interest, extracting genetic markers that enable them to quickly build up a picture of biodiversity in the area.

In Western Australia, BHP is using eDNA to help track and monitor the endangered Pilbara Olive Python. And Anglo American is sharing its eDNA information with a global databank to support wider conservation science.

Pilbara Olive Python, Australia

In the rugged landscapes of Western Australia's Pilbara region, a cryptic and elusive inhabitant, the Pilbara Olive Python, is the focus of a ground-breaking two-year monitoring programme. 

The python spends most of its life in rocky habitats and dense vegetation, evading conventional detection methods. Consequently, the project is using innovative tracking technologies to follow the pythons as they live and move within their habitat. It is a multi-team effort, involving BHP, programme consultants Helix solutions and Biota Environmental Sciences, and the eDNA Frontiers Laboratory at Curtin University.

Environmental DNA extraction techniques are used to survey species composition and communities at specific locations. Samples are taken from water sources, and the team analyse genetic material to record python activity. It is both cost-effective and non-invasive.

The team are also tagging pythons with high-frequency radio transmitters. The process involves capturing individual pythons and fitting radio tags under anaesthetic, in accordance with state regulations for this kind of work.

While still in its early stages, the programme is already providing an enhanced understanding of the python's basic biology and ecology, as well as valuable insights into the pythons’ abundance and activity patterns across changing seasons.

BHP is now looking at opportunities to expand the programme to include additional sites and obtain a wider, regional perspective of the Pilbara Olive Python population.

Biodiversity in caves

In the Carajás Mountains of northern Brazil, the Vale Institute of Technology is investigating the region’s ferruginous underground cavities - also known as iron-rich caves.

The enormous cave system is a surprisingly rich ecosystem, home to bats, a variety of plants and fungi, as well as insects and other organisms.

The institute is combining state-of-the-art genomic tools and molecular biology, including eDNA and population genetics, to uncover the biodiversity that is hiding underground. Combined with telemetry and bioacoustics, it is enabling the Vale team to create strategies to improve the management and protection of nature

A global atlas of life 

The fight to prevent mass extinction is being hampered by huge gaps in scientific knowledge, particularly locations and frequencies of species. The eBioAtlas programme, launched in 2021, aims to fix this by gathering huge amounts of eDNA data to better understand biodiversity on a global scale.

Initially, the project is targeting dozens of high-risk areas where nature is under threat. Over 30,000 water samples are being collected in the first three years, using specially designed eDNA kits to stabilise the genetic material in the water for later analysis. 

Back in the lab, the eBioAtlas team sequences DNA fragments to build up a picture of the species that live in those areas. By analysing multiple samples, they can identify the range and distribution of land animals, fish, birds and amphibians within each ecosystem. This technique has several advantages over traditional biodiversity surveys, which rely on teams of experts being on-site to identify species by sight or from camera footage.

Several eDNA-gathering projects have already been run by Anglo American across sites in South Africa, Zimbabwe, Finland and Peru. In the UK, the company’s research at the Woodsmith polyhalite project has identified 522 distinct taxonomic groups of invertebrates and 67 groups of vertebrates.

Scientists have also detected over 500 species of aquatic insects, which give them a baseline measurement of biodiversity and ecosystem health at the site, to compare against in future years. Understanding and quantifying the numbers of species in this way is a crucial step towards restoring biodiversity.

Anglo American is sharing its eDNA biodiversity data with the eBioAtlas initiative, to help build a worldwide databank of species information. It is also sharing information with local organisations to help build genetic reference libraries and support regional monitoring and research.

There are clear, tangible benefits to the use of eDNA in mining. Anglo American is utilising the data to monitor and evaluate its biodiversity performance, so that when an operation closes, it has a precise roadmap to rejuvenate the environment and ecosystems to better than its pre-mining state. This is only the start of the transformative potential of measurement in forging a nature positive future.