Effect of biotic and abiotic factors on the production and degradation of fish environmental DNA: An experimental evaluation

Abstract

Species monitoring is essential for effective management of aquatic resources as it provides crucial information about the distribution and abundance of species (Gibbs, 2000). While efficient and obviously useful, traditional methods used for fish population surveys (e.g., gillnets, seine, scuba diving, etc.) can be invasive, costly, time consuming, and selective. This may result in a biased estimation of species occurrence (Boivin-Delisle et al., 2021;Lodge et al., 2012;Sigsgaard et al., 2015). A more time-efficient tool that has been recently developed is environmental DNA (eDNA), which can also greatly reduce the cost of species monitoring by lowering both the

Integrating physiology and environmental dynamics to operationalize environmental DNA (eDNA) as a means to monitor freshwater macro‐organism abundance

“…Previous experiments examining the effect of temperature on eDNA production typically do so across a small number of temperature treatments (e.g., 2–3 treatments) (e.g., Jo et al, 2019; Klymus et al, 2015; Lacoursière‐Roussel, Rosabal, et al, 2016; Robson et al, 2016; Takahara et al, 2012); future experiments should attempt to quantify the effect of temperature on eDNA concentrations across a wider (and finer) gradient of temperatures to deduce the general shape of the temperature dependency function of eDNA production. Most previous experiments have also been conducted at temperatures above 10°C, with only a handful of previous studies experimentally evaluating the effect of temperatures below that threshold (Caza‐Allard et al, 2021; Lacoursière‐Roussel, Rosabal, et al, 2016; Takahara et al, 2012); there is also an acute need to study the effect of low temperatures on eDNA concentrations, particularly for temperate species.…”

“…Research has demonstrated conflicting effects of temperature on eDNA concentrations (Caza‐Allard et al, 2021; Curtis et al, 2020; Jo et al, 2019; Klymus et al, 2015; Lacoursière‐Roussel, Rosabal, et al, 2016). This may result from a focus on steady‐state concentrations of eDNA in experimental replicates, as opposed to a focus on eDNA production rates, per se (Jo et al, 2019).…”

Thirteen novel ideas and underutilised resources to support progress towards a range‐wide American eel stock assessment

“…American eel densities, a valuable parameter in stock assessments, are available only in scattered locations (Table S5). eDNA concentrations change with seasonal cycles of eDNA release, and degradation dispersion varies with physical and chemical water characteristics and currents (Caza‐Allard et al, 2022; Kasai et al, 2020; Laporte et al, 2020; Takeuchi et al, 2019). eDNA concentrations explained 57% of the variation in estimated aquatic species abundance in 25 studies conducted in natural waters (Yates et al, 2019).…”

Environmental DNA reveals fine‐scale habitat associations for sedentary and resident marine species across a coastal mosaic of soft‐ and hard‐bottom habitats

“…One explanation for this effect could be that plaice were less abundant at the study sites in summer (late June) compared with spring (late April), potentially moving to deeper waters to avoid the higher water temperatures and thereby causing a higher proportion of samples to yield zero amplifications. Alternatively, eDNA particles are known to degrade more rapidly when exposed to higher temperatures (Caza‐Allard et al, 2021; Saito & Doi, 2021a), which could also explain the observed temperature effect for plaice. However, no similar effects of temperature were found for the remaining three focal species (95% CI's included zero, Figure S8), making it more likely that the effect in plaice was due to a temperature‐driven shift in the spatial distribution of plaice within the study area, a trend at least partly confirmed by BRUVS observations (Figure S7c).…”