Connecting the DOTs: eDNA Technology and Marine Conservation

Welcome aboard!

Today, we embark on an exciting journey into the depths of marine conservation, guided by the innovative technology of environmental DNA, or eDNA. In this weeks topic, we'll explore the transformative power of eDNA in revolutionising our approach to preserving the oceans' delicate ecosystems. We shall be uncovering what eDNA is and how it's changing the game in marine conservation, exploring the diverse applications of eDNA technology, its potential impact, and the challenges faced in implementing it. Through our exploration, we'll uncover the untapped potential of eDNA to revolutionise how we understand and protect our oceans.

So, grab your snorkel and let's dive in! 🌊

How eDNA Works:

eDNA technology allows the monitoring and analysis of biodiversity in marine ecosystems. It works by detecting traces of genetic material shed by organisms into their surrounding environment, such as water or sediment. When organisms swim, shed skin cells, excrete waste, or leave behind other biological materials, they release DNA into their surroundings. This can then be collected from water samples and analysed using advanced molecular techniques, such as polymerase chain reaction (PCR) and DNA sequencing.

These molecular methods allow scientists to amplify and sequence specific regions of DNA, enabling the identification of the organisms present in a given sample. By comparing the genetic sequences obtained from environmental samples to known reference sequences in genetic databases, researchers can determine the presence and abundance of various species within a marine environment. This non-invasive approach eliminates the need for direct observation or capture of organisms, making it ideal for studying elusive or rare species and monitoring biodiversity over large spatial scales.

Moreover, eDNA analysis can provide insights into the broader ecological dynamics of marine ecosystems, including interactions between species, habitat preferences, and responses to environmental changes. By harnessing the power of eDNA technology, researchers can gain a deeper understanding of marine biodiversity and ecosystem health, informing conservation efforts and management strategies (1).

Applications of eDNA in Marine Conservation:

eDNA technology has revolutionised marine conservation efforts by offering a non-invasive and highly sensitive method for monitoring biodiversity and ecosystem health. The applications of eDNA in marine conservation are diverse and encompass various aspects of ecosystem management and protection.

1. Biodiversity Monitoring: One of the primary applications of eDNA in marine conservation is biodiversity monitoring. By analysing eDNA samples collected from different marine environments, researchers can identify the presence and abundance of a wide range of species, from fish and marine mammals to microorganisms and algae. This information helps scientists track changes in species distributions, monitor the spread of invasive species, and assess the effectiveness of conservation measures.
   

2. Habitat Assessment: The tech can be also used to assess the quality and condition of marine habitats. By analysing eDNA samples collected from different habitats, such as coral reefs, seagrass meadows, and mangrove forests, researchers can evaluate the health and resilience of these ecosystems. This information is crucial for identifying areas in need of conservation intervention and prioritising habitat restoration efforts.
   

3. Species Conservation: It plays a vital role in species conservation by providing data on the distribution and status of endangered or threatened species. By monitoring eDNA samples from known habitats or potential habitats, conservationists can assess the viability of populations, detect population declines, and inform conservation strategies to protect vulnerable species.
   

4. Biosecurity and Invasive Species Management: It can help with biosecurity and invasive species management efforts. By analysing eDNA samples from water bodies and ports, researchers can detect the presence of invasive species at an early stage and implement rapid response measures to prevent their establishment and spread. This proactive approach is essential for protecting native biodiversity and ecosystems from the negative impacts of invasive species.
   

5. Climate Change Research: eDNA technology is increasingly used in climate change research to assess the impacts of environmental changes on marine ecosystems. By monitoring eDNA samples over time, researchers can track shifts in species distributions, pollution, changes in community composition, and other ecological responses to climate change. This information helps scientists understand the resilience of marine ecosystems and develop strategies to mitigate the impacts of climate change on marine biodiversity (2).
   

Breakdown of a DOT Sampler:

The Deployment of a Drifting Oscillating Tube (DOT) sampler is a commonly used method for collecting eDNA samples from marine environments. The DOT sampler consists of a cylindrical tube equipped with a membrane filter at one end and a weight at the other end. The sampler is deployed in the water column, where it drifts with ocean currents, collecting eDNA from the surrounding water. After a designated period, typically ranging from a few hours to several days, the sampler is retrieved, and the filter is removed for eDNA analysis. This method allows researchers to collect eDNA samples from specific depths and locations in the water column, providing valuable insights into the distribution of marine organisms and their habitats. See a graphic breakdown below:

(3) Breakdown of a DOT eDNA sampler

eDNA and Impact:

The technology holds significant promise for improving impact measurement in marine conservation efforts. By analysing eDNA samples collected from marine environments, scientists can gain valuable insights into the presence and abundance of species, assess habitat quality, and monitor changes in biodiversity over time. This data allows for more accurate and efficient evaluation of conservation initiatives, helping to determine their effectiveness and guide future management strategies. Furthermore, the innovative nature of eDNA technology attracts investment and fosters innovation in the field of marine conservation. Investors recognise the potential of eDNA technology to provide actionable insights for conservation decision-making, driving funding and support for research and development in this area. As eDNA technology continues to advance, it offers new opportunities for collaboration between scientists, policymakers, and investors, leading to more effective and sustainable solutions for protecting our oceans.

Future Implications/challenges

One of the key challenges of eDNA technology in marine conservation is the potential for environmental variability to affect the detection and interpretation of genetic signals. For instance, factors such as water temperature, salinity, and microbial activity can influence the degradation and persistence of eDNA in aquatic environments. This variability may lead to false-positive or false-negative results, affecting the accuracy and reliability of eDNA-based assessments of biodiversity and ecosystem health. Additionally, standardising sampling protocols and data analysis methods across different studies and environments remains a challenge, hindering comparability and reproducibility of results. Addressing these challenges requires ongoing research and methodological refinement to improve the robustness and applicability of eDNA technology in marine conservation (4).

Reflections and Thanks

From uncovering the mysteries of eDNA and its applications in biodiversity monitoring to confronting the challenges and opportunities it presents, we've covered significant ground in understanding its role in marine conservation. Looking ahead, I'm thrilled to announce that next week, we'll be diving into the realm of artificial intelligence (AI) for marine conservation.

In wrapping up our exploration of eDNA in marine conservation, I want to extend my sincere gratitude to you for taking the time to read this blog. Your engagement and support are invaluable as we continue to delve into innovative solutions for protecting our oceans. I invite you to share your feedback, suggestions, and recommendations for future topics you'd like to explore.

Until next week, keep the conversation going, and let's continue working together to protect our blue planet.

Sources/further reading

1. Deiner, K., Bik, H. M., Machler, E., Seymour, M., Lacoursiere-Roussel, A., Altermatt, F., ... & Bernatchez, L. (2017). Environmental DNA metabarcoding: transforming how we survey animal and plant communities. Molecular Ecology, 26(21), 5872-5895.

2. Beng, K.C. and Corlett, R.T., 2020. Applications of environmental DNA (eDNA) in ecology and conservation: opportunities, challenges and prospects. Biodiversity and Conservation, 29, pp.2089-2121.

3. Hendricks, Andre & Mackie, Connor & Luy, Edward & Sonnichsen, Colin & Smith, James & Grundke, Iain & Tavasoli, Mahtab & Furlong, Arnold & Beiko, Robert & Laroche, Julie & Sieben, Vincent. (2023). Compact and automated eDNA sampler for in situ monitoring of marine environments. Scientific Reports. 13. 10.1038/s41598-023-32310-3.

4. Barnes, M. A., Turner, C. R., Jerde, C. L., Renshaw, M. A., & Chadderton, W. L. (2014). Environmental conditions influence eDNA persistence in aquatic systems. Environmental Science & Technology, 48(3), 1819-1827.