Detection of environmental DNA of the invasive red-eared slider in ponds for evaluating their distribution with comparison to water quality

Abstract

Environmental DNA (eDNA) is a powerful tool for monitoring the distribution of aquatic macro-organisms. However, environmental factors, including the water temperature and water quality, can affect the inhibition and/or degradation of eDNA, which prevents accurate estimations of eDNA concentrations and the detection of the presence/absence of species in natural habitats. Also, very few eDNA studies have been conducted for reptiles, especially with respect to estimating their biomass and/or abundances. Here we examined the relationship between the visually-observed number of red-eared sliders (Trachemys scriptaelegans) and the eDNA concentrations. Additionally, we evaluated the effect of water quality on the eDNA concentration in 100 ponds. We found that there was a significant positive correlation between the observed number of red-eared sliders and the eDNA concentration in the ponds. On comparing various water quality indicators, including dissolved nitrogen, dissolved phosphorous, organic matter, and chlorophyll a (Chl. a), we found that only Chl. a had a negative correlation with the red-eared slider eDNA concentration, while we did not find any inhibitions in the quantitative PCR. We conclude that concentrations of eDNA can potentially be used for estimating the abundance of the red-eared slider. Additionally, Chl. a might indirectly influence the degradation of eDNA through the microorganisms bonded to the phytoplankton in the ponds, which microbial activity thought to be decreasing eDNA.

Environmental DNA degradation simulation from water temperature and DNA fragment length: A meta-analysis approach

“…Environmental DNA (eDNA) methods are innovative methods developed for monitoring macroorganisms, especially aquatic species (Ficetola et al, 2008; Takahara et al, 2012; Minamoto et al, 2012; Taberlet et al, 2012; Ushio et al, 2018; Tsuji et al, 2019; Kakuda et al, 2019). The eDNA method is used to investigate species distribution, so it is less invasive to the environment and organisms, and is especially useful for rare and endangered species, which generally have low tolerance to sampling disturbance.…”

Research and prospects of environmental DNA (eDNA) for detection of invasive aquatic species in East Asia

“…Successful eDNA surveys have been conducted to assess the distribution of Pacifastacus leniusculus in streams of Hokkaido (Ikeda et al, 2019). Further applications of eDNA methods have facilitated the detection of Lithobates catesbeiana and P. clarkii (Ogata et al, 2022), followed by an indepth analysis of the influence of water quality and the abundance of T. s. elegans on the eDNA concentration of T. s. elegans in ponds (Kakuda et al, 2019). In China, DNA metabarcoding techniques have been employed to monitor the invasion of P. canaliculata in the Suzhou area.…”