Passive Gauze-Based eDNA Sampler Proves Efficient and Cost-Effective in the Marine Environment

Abstract

While environmental DNA (eDNA) is an increasingly valuable tool for marine biodiversity monitoring, the high cost of conventional eDNA sampling methods may limit long-term or large-scale applications. Here, we present the first empirical comparison of the metaprobe 2.0, a low-cost, passive eDNA sampler, against an industry standard Sterivex filtration method using dip-collected 1-L water samples (“water bottles”). Although the metaprobe has been used in a limited number of prior studies—primarily in comparison to traditional net-based sampling—its adoption remains limited, and this is the first study to benchmark its performance directly against a widely used eDNA sampling methodology. Across 14 joint deployments, we assessed detection and quantification of eDNA of two elasmobranch and two teleost species. While Sterivex filters outperformed metaprobes in detecting copies of DNA, metaprobes showed comparable detection performance within biologically significant margins and exhibited a lower variance among sampling replicates. Our study is the next step in the upscaling of this passive sampler and establishes a workflow for integrating metaprobes into biodiversity and species monitoring in marine ecology. We outline the methodological deviations from a “traditional” Sterivex filter eDNA workflow and identify how metaprobes might widen the accessibility of eDNA monitoring in the future through their simple yet effective sampling, filtering, and preservation protocols.