No pump, no problem: evaluating passive eDNA sampling for marine biomonitoring of a nuisance macroalga

Passive environmental DNA (eDNA) sampling proves equally effective as active filtration for detecting the nuisance macroalga Chondria tumulosa in remote marine environments, offering a cost-effective and scalable alternative. The study found that 15-minute deployments of passive eDNA samplers (PEDS), when paired with increased qPCR replicates, matched the detection sensitivity of traditional active filtration methods, successfully identifying C. tumulosa at low abundances (<1%) in all known cases within the Papahānaumokuākea Marine National Monument. While PEDS showed higher probabilities of false-positives and false-negatives compared to active sampling, they performed comparably across stationary buoys and roving SCUBA divers, with absorbent cotton rounds outperforming research-grade filters in DNA yield reliability. The findings highlight the potential of passive eDNA sampling for biomonitoring cryptic taxa in resource-limited settings, though further optimization is needed to minimize erroneous detections.

Nichols, P. K., & Marko, P. B. (2025). No pump, no problem: evaluating passive eDNA sampling for marine biomonitoring of a nuisance macroalga. PeerJ, 13, e19939. Portico. https://doi.org/10.7717/peerj.19939