Table 3 Extracted variables, characteristics, and examples

Year

Year in which the study was published

Country

Country where the study was realized (independently if the authors or the institution that realized the research are from a different country)

Data availability

Public access to sequences runs obtained by environmental DNA (Those data are presented mainly in the form of SRA accession numbers, or bioproject numbers)

Studied group

Taxonomic groups studied or identified through eDNA framework (fishes, plants, fungi, mammals, etc.)

Platform

The sequencing platform used for the genetic material obtained via eDNA (Illumina, 454, Nanopore, etc.)

Technique focus

The technique employed for amplify, assign, and/or process the eDNA sample (metabarcoding, Whole Genome Sequencing, Transcriptomics, etc.)

V region

The hypervariable region reported to be used in the study, for taxonomic resolution of eDNA analysis (V4, V5, V6, etc.)

Fragment

Any of the conserved regions or fragments in case they were reported (16S, 18S, COI, rubcL, ITS, etc.)

Fraction used

The environmental matrix where eDNA was obtained (water, sediment, mixed sample containing water and sediment, etc.)