Data from: Quantifying relative fish abundance with eDNA: a promising tool for fisheries management

Assessment and monitoring of exploited fish populations are challenged by
costs, logistics and negative impacts on target populations. These factors
therefore limit large-scale effective management strategies. Evidence is
growing that the quantity of eDNA may be related not only to species
presence/absence, but also to species abundance. In this study, the
concentrations of environmental DNA (eDNA) from a highly prized sport fish
species, Lake Trout Salvelinus namaycush (Walbaum 1792), were estimated in
water samples from 12 natural lakes and compared to abundance and biomass
data obtained from standardized gillnet catches as performed routinely for
fisheries management purposes. To reduce environmental variability among
lakes, all lakes were sampled in spring, between ice melt and water
stratification. The eDNA concentration did not vary significantly with
water temperature, dissolved oxygen, pH and turbidity, but was
significantly positively correlated with relative fish abundance estimated
as catch per unit effort (CPUE), whereas the relationship with biomass per
unit effort (BPUE) was less pronounced. The value of eDNA to inform about
local aquatic species distribution was further supported by the similarity
between the spatial heterogeneity of eDNA distribution and spatial
variation in CPUE measured by the gillnet method. Synthesis and
applications. Large-scale empirical evidence of the relationship between
the eDNA concentration and species abundance allows for the assessment of
the potential to integrate eDNA within fisheries management plans. As
such, the eDNA quantitative method represents a promising population
abundance assessment tool that could significantly reduce the costs
associated with sampling and increase the power of detection, the spatial
coverage and the frequency of sampling, without any negative impacts on
fish populations.