While GCN samples could be analysed for other species, this is not recommended due to the small volume of water processed (90 ml) which limits the amount of eDNA that can be captured and will likely result in lower detection rates. Instead, we recommend collecting a larger sample (up to 3 L) and filtering the water using our Aquatic eDNA Kits. Email eDNA-lab@naturemetrics.co.uk for more information on these kits and available analyses.