In a groundbreaking journey across the Southern Ocean, scientists have harnessed the power of DNA technology to shed new light on the diverse marine life thriving in this remote and vulnerable region. By combining cutting-edge environmental DNA (eDNA) analysis with traditional zooplankton sampling methods, researchers are gaining unprecedented insights into the intricate web of life that exists beneath the waves. This research, published in the Science of The Total Environment journal, not only promises to enhance long-term monitoring of Southern Ocean ecosystems but also provides a crucial tool for detecting and mitigating the threat of non-native species introductions, which could have devastating consequences for the region’s delicate balance.
The Power of eDNA Monitoring
While the traditional means of zooplankton monitoring in the Southern Ocean (by Continuous Plankton Recorder (CPR)) provides important long-term data for biotic communities over this region, it is limited by spatial resolution and temporal coverage [7]. Nevertheless, this method is also not ideal as many delicate and gelatinous organisms are often crushed or missed.
Scientists have released a fuller account of the region’s animals near and far, this time moving into the new frontier of DNA analysis. The scientists identified a greater diversity of zooplankton species through the genetic signatures they detected in seawater samples, compared with traditional CPR ranks. So not only does this unique method account for a broader view of the ecosystem, but it also has implications for identifying non-native or invasive species that could threaten the delicate Antarctic interior.
Sailing in the Southern Ocean
This study demonstrates the value of using eDNA and traditional sampling in concert to obtain a more complete ecological picture, particularly for Southern Ocean marine communities. The CPR is great for detecting sturdy organisms like crustaceans, but more delicate and elusive species such as gelatinous zooplankton can be identified using DNA.
An integrated approach such as EPDD allows useful information to be extracted from sound data which can be easily forgotten. Its importance only increases as the impacts of climate change continue to change the face of the Southern Ocean. By analyzing shifts in zooplankton communities, scientists can learn more about the surrounding ecosystem and potentially recognize important transition points or responses to changes in the environment. This knowledge is key to providing what’s needed for conservation and policy shaping, to protect the exclusive and tender Antarctic marine wilderness.
Protecting the Biosecurity of Antarctica
The findings also have wider implications in that human-introduced invading species could pose a serious risk if they were to colonize the Southern Ocean, as biosecurity is already at risk here from non-indigenous marine invasive species. The eDNA analysis also detected the presence of several non-native or potentially invasive species, especially closer to Tasmania where these species are already found.
Although the researchers warn that in some cases these detections could be non-viable or possibly dead organisms, the ability for hull biofouling to bring non-native species to Antarctica is a serious concern. The Australian Antarctic Program has taken steps to mitigate this on its new icebreaker the RSV Nuyina, with a comprehensive biofouling management plan which will help reduce the risk of invasions.
This formation of Antarctic MIKU, coupled with the power of a new technique in eDNA monitoring, will engage both scientists and conservationists to monitor and act on these threats for this precariously balanced ecosystem of the Southern Ocean. With the whole region suffering the impacts of a warming world, this technology will be a key tool as we work to protect the unique marine biodiversity in Antarctica.
