This article was originally published in Chagos News, The Periodical Newsletter of the Chagos Conservation Trust and Chagos Conservation Trust US, Issue No. 57, December 2020.
The British Indian Ocean Territory Marine Protected Area is famous for its size, yet at this scale the monitoring responsibilities present major logistical and financial challenges.
At NatureMetrics, we are helping CCT to establish new DNA-based biodiversity monitoring tools to increase the power of the data obtained and increase the pace at which it’s collected.
CCT has been proactively seeking novel ways to monitor the islands of the Chagos Archipelago, namely due to 95% of the landmass being classed as degraded and conventional monitoring methods being time consuming and costly.
The degradation is mostly caused by habitat destruction and the presence of invasive rats, both resulting in a marked reduction of biodiversity. Without healthy seabird populations supplying nutrients, the coral reefs are less likely to thrive, and there are many more wildlife relationships that are being threatened as biodiversity is lost.
Conducting wide-scale spatial biodiversity surveys is a large undertaking, and doing them regularly adds another layer of costly considerations.
Biodiversity monitoring and field surveys for marine and terrestrial habitats typically require teams of specialists being deployed to remote locations, who then spend several weeks in the field gathering data using conventional monitoring techniques (e.g. dive transects, BRUV, tagging, rodent trapping, camera trapping, fish netting, bird transects etc.).
With a greater number of specialists needed in the field to identify and monitor a wide range of taxonomic groups, the health and safety risks to staff–as well as costs in terms of person days in the field–increase exponentially.
Biodiversity monitoring is hugely valuable, and we rely on the resulting data for managing our natural world. The scientific community has therefore set out to develop new ways to improve the speed at which we can collect biodiversity data, and improve the resolution at which we can detect different plants, animals and even microfauna.
Here at NatureMetrics, we’re using a biomonitoring method called environmental DNA metabarcoding.
Environmental DNA, or eDNA, is the DNA that is left in the environment by living things. Similar to a crime scene where humans leave their DNA behind, animals do the same whenever they interact with their habitat–even in the air.
Whether it’s a fish swimming amongst a coral reef, or an invasive rat foraging on land, all living things leave traces of their DNA in the environment. We capture this DNA, using the NatureMetrics filter pictured, and identify which animals are living where, and when.
We have had huge successes with using eDNA-based surveys for marine and terrestrial life. From fishes to dolphins and lizards to birds, we can capture biodiversity data for whole ecosystems just based on the DNA that the animals have left behind.
In coral reefs, it’s possible to simply collect water samples from a boat and then send the samples back to the lab, where we can tell you what DNA has been found in your water sample.
This can describe coral reef health in a way that is objective, rapid and reliable, especially when there is limited time or financial resources. It’s these inventories of whole vertebrate communities that allow us to start understanding what lives in a system, and how it changes over time.
Having learned about these DNA-based methods, CCT saw the potential in using these methods for wide-scale monitoring of the Chagos Archipelago and reached out to NatureMetrics for advice on monitoring firstly the presence of rats, and secondly the marine life in the Chagos Archipelago that is inextricably linked to the presence of seabird communities and rats.
Both types of data could be used to inform long-term monitoring of the impact of invasive species, as well as the success of eradication programmes and habitat restoration on the associated reef ecosystems of the islands.
By identifying the challenge and approaching NatureMetrics, CCT is now in a position to readily generate big datasets that can impact real-world solutions.
For more information on eDNA, metabarcoding and molecular techniques for biodiversity monitoring please visit the NatureMetrics website or e-mail their team directly – firstname.lastname@example.org and email@example.com.