The involvement of citizen scientists is increasingly recognised as a crucial component of public engagement in conservation science projects. The ease of use and wealth of information that can be gathered using environmental DNA (eDNA) samples has made collection of eDNA samples a preferred and popular citizen science activity. However, for the collected samples to be effectively used in species monitoring, there is a need to standardise the volume of water filtered at each sampling location.
In this report, a systematic literature search was combined with a grey literature search to identify the most promising manual filtration methods for the processing of water samples by citizen scientists. The top three methods were subsequently trialled by nine volunteers to assess the manual difficulty of each method and to determine the volume of water filtered.
Filtration using a syringe attached to a 0.45 um sterivex filter assisted by a silicone gun was found to have the lowest scores for physical difficulty and pain, whilst also filtering comparable water volumes to the other trialled methods. DNA concentrations and quality were comparable across the three trialled methods. Based on the results from this work an number of recommendation were made for designing eDNA sampling protocols using manual filtration methods.