Can analyzing DNA in water and sediment samples replace the collection of live specimens? Recent studies suggest that Environmental DNA (eDNA) collection may be a viable, safe, and cost effective alternative for biodiversity studies in marine environments.
Battelle is working with the oil and gas industry to validate eDNA methods for marine environments, from near-shore lagoons to deepwater benthic environments. Recent studies comparing eDNA to traditional collection methods have produced encouraging results. In the near future, eDNA studies could be used to supplement or supplant more costly collection methods for environmental monitoring and impact studies.
Traditional biodiversity studies require experts to spend extensive time in the field to collect, observe and identify species. eDNA studies compare DNA extracted from shed cells and excretions found in water and sediment samples to a catalog DNA sequences of known species for fast and easy species identification in the lab. This means that biodiversity studies can be completed with significantly fewer field personnel, reducing costs and risks.
Battelle completed proof-of-concept studies in marine environments off of the North Slope of Alaska and in a deepwater environment off of French Guiana. Environmental DNA studies of sea water from Elson Lagoon, near Barrow, Alaska demonstrated a high level of agreement with both subsistence fishing and scientific collecting methods in the identification of fish present in the lagoon. The eDNA study also identified several fish species that were not caught by traditional methods, as well as four species of marine mammals and numerous invertebrates, suggesting that eDNA may be a superior method for detecting the presence of rare, endangered or hard-to-capture species. Studies of mollusks, crustaceans and annelids in deepwater environments demonstrated more mixed results, in large part because many of these deepwater species have not been sequenced and added to DNA catalogs. As more species are sequenced and cataloged, eDNA studies in deepwater environments will become more accurate and complete.
Regulatory agencies are starting to take notice of these new analytical methods. Battelle’s validation studies are an important step toward getting regulatory approval to replace or supplement traditional study methods for required environmental impact studies and monitoring. For example, eDNA could be a cost-effective way to monitor “sentinel species” to evaluate environmental impacts over time.
Battelle is continuing to advance the science of eDNA collection and analysis for the oil and gas industry. One exciting possibility for the future is the marriage of eDNA analysis with automated sampling techniques using Autonomous Underwater Vehicles (AUVs) like Bluefin. Combining robotic sample collection with eDNA analysis would further reduce the time, costs and risks of field biodiversity studies and long-term monitoring.