Results of the trials led to investigate the effect of filtration system (eDIYsampler vs. Nalgene filtration unit) on A) the volume filtered, B) the eDNA concentration when the same volume is filtered, C) the Ct-value found by qPCR when it comes to target C. quadricarinatus in Martinique rivers and D) the reads count recovered by metabarcoding, for fish and decapods detection.