Environmental DNA (eDNA) collection techniques across diverse ecosystems: a mini-review of promising new tools for eDNA metabarcoding

Abstract

Environmental DNA (eDNA) analysis has significantly transformed the way biodiversity assessment and monitoring are conducted in many environments. This review study synthesizes findings from multiple studies to provide a comprehensive overview of eDNA collection strategies in diverse settings. The review examines the techniques used for sampling eDNA in water, air, soil, sediment, and coral reef ecosystems. Water filtration, sediment sampling, and passive sampling devices are commonly used methods for collecting eDNA in aquatic environments. These techniques provide non-invasive ways to identify and track aquatic organisms, offering vital information about the interactions within the community and the global distribution of species. Similarly, the use of airborne eDNA sampling techniques is becoming increasingly promising for evaluating biodiversity on land, although there is room for improvement. Soil eDNA extraction techniques involve the use of soil coring to collect samples, followed by DNA extraction from these samples, and the application of metabarcoding methods. These techniques allow for thorough investigations of biodiversity in the soil. Specialized techniques for collecting eDNA are required for coral reef ecosystems due to their intricate habitat structure and fluctuating water conditions. The importance of choosing appropriate techniques for eDNA collection based on ecosystem parameters and research objectives is emphasized by comparative analysis. This mini-review consolidates knowledge from a selected body of recent studies and serves as a helpful resource for scholars and practitioners involved in biodiversity monitoring and conservation across diverse ecosystems.

Keywords: Biodiversity monitoring; Metabarcoding; Passive method; Rapid method; eDNA.