Environmental DNA (eDNA) for the management of marine living resources
Developments in the field of genetics have transformed our understanding of the natural world. In a fisheries context, it has helped us identify species, define population structures, begin to understand the genetic basis of adaptive traits, and monitor adaptive population changes. Typically, such insights have been gained from the analysis of DNA obtained from tissue samples collected directly from individuals across a study area. Additionally, the analysis of DNA through metabarcoding from a bulk sample composed of a mixture of individuals of different zooplankton and/or macroinvertebrate species has enabled cost-effective and efficient biodiversity assessments. Recently, a new source of DNA is being used for analysis of macro species - so-called “environmental DNA” (eDNA), made up of DNA shed from individuals into the natural environment. Uptake of novel approaches using eDNA promises to revolutionize biodiversity monitoring by allowing the detection of larger organisms without the need to directly sample them, or of small/rare ones whose presence would not be otherwise picked up. This is of particular use in the marine environment where traditional sampling is often challenging.
Management and monitoring
Ecosystem-based management increasingly demands regular monitoring of the marine environment and its living resources. Progress with recent genetic technologies and their routine employment have provided powerful and reliable tools to address a diversity of issues spanning biosurveillance, biosecurity, conservation, ecosystem and biodiversity monitoring, and aquaculture and fisheries management. eDNA is the genetic material released from an organism into its environment through physiological and mechanical processes. It persists in the environment for some time and can be collected for analysis. In the case of fish, eDNA stems from waste products, skin/tissue, scales, eggs and sperm, mucus, blood, and carcasses. In contrast to DNA extracted from tissue samples, or community DNA where DNA is extracted from whole organisms, eDNA does not require sampling the target organisms.
The benefits of using eDNA based approaches are numerous and can prove invaluable in monitoring marine environments. The field is relatively new, but developing at a fast pace, with new applications continuously being optimized, including the deployment of autonomous underwater vehicles (AUV). At a time when the marine environment is under threat, eDNA-based techniques are a cost-effective resource to provide information to managers and policy-makers, and hence aid in the conservation and sustainable exploitation of aquatic living resources.
The full article can be found at ices.dk