Fig 1.
Studied catchment area and localization of the sampling sites.
(A) Map of the studied catchment area and localization of the sampling sites: The dotted red lines show the eDNA sampling trajectory on the Aiguebelette lake: La = Left/West bank (4.7 km) trajectory, Lb = Right/East bank (6,7 km) trajectory, Lc = Middle (3,5 km) trajectory; IM1 and IM2, sampling sites on the impoundment respectively 0.2 km and 1.3 km from the lake outlet; R0, R1 and R2, sampling sites on the Tier river respectively 1.7, 3.6 and 6.9 km downstream from the lake outlet. Pictures of Aiguebelette Lake from the south side (B), impoundment at IM1 (C) and Tier River at R0 (D), R1 (E) and R2 (F). Photo credits: M. Bouron (B) and R. Civade (C to F).
Table 1.
Sampling site characteristics for the Aiguebelette lake, the impoundment and the Tier River downstream from the dam.
Table 2.
Fish species detected using eDNA metabarcoding (three filtrations) and gillnets during the sampling campaigns operated together in 2014 in the Aiguebelette lake.
Table 3.
Fish species detected using eDNA metabarcoding (six filtrations) and complete electrofishing during the sampling campaigns operated together in 2014 at the R1 site.
Table 4.
Fish species detected using eDNA metabarcoding (six filtrations) and complete electrofishing during the sampling campaigns operated together in 2014 at the R2 site.
Table 5.
Fish species detected using eDNA metabarcoding (three filtrations in 2014) and the seven gillnets sampling campaigns (from 1995 to 2014) within the Aiguebelette lake.
Table 6.
Fish species detected using eDNA metabarcoding (12 filtrations in 2014) and the 13 electrofishing sampling campaigns (from 1988 to 2015) within the Tier River.
Fig 2.
First factorial map of the correspondence analysis based on the whole dataset.
Color codes for the different localities sampled in 2014 using eDNA metabarcoding (dots): lake (L, green), impoundment (IM1 and IM2, red), Tier River (R0: dark blue, R1: light blue, R2; pink). The results of the different filtrations are indicated by a letter following the site name: three for L (a-c) and R0 (a-c), six for R1 (a-f) and R2 (a-f). Traditional fish samples added as supplementary individuals (crosses for previous fishing sessions and triangles for simultaneous fishing sessions in 2014): green (Lake), dark blue (R0), light blue (R1), pink (R2) and orange colors (other river sites). The plain and dashed line ellipses define the area encircling 95% of the samples for a given site for the eDNA analysis and the combined traditional fishing campaigns, respectively. Bottom left, histogram of the inertia distribution per axis.
Table 7.
Fish species detected by eDNA metabarcoding in 2014 within the impoundment (IM1 and IM2 samples) and at the R0 site (downstream from the dam, three filtrations).