DNA-based monitoring of the alien invasive North American crayfish Procambarus clarkii in Andean lakes (Ecuador)

Abstract

In 2013 the red swamp crayfish (Procambarus clarkii) was introduced in Lake Yahuarcocha, a tropical, high altitude lake located in the Andes of northern Ecuador. Abundance of this alien invasive species has increased to such extent that it is disturbing the autochthonous aquatic ecosystem. Little is known about its distribution throughout Ecuador. Monitoring is therefore important to assess the current distribution and to control future spread. A molecular method based on environmental DNA (eDNA) was developed and used to assess the distribution of P. clarkii at 21 sites in Lake Yahuarcocha, and three sites each at Lake Mojanda and Lake San Pablo in the Ecuadorian highlands. The molecular detection of crayfish from water samples were compared to catch-based distribution patterns obtained from traditional trapping. Results showed an eDNA detection accuracy of 86% in water samples, without any false positives. The results indicate that this budget-friendly method is easy to use and can provide important information on the occurrence of alien species in the tropics.

Opportunities and Challenges for the Sustainability of Lakes and Reservoirs in Relation to the Sustainable Development Goals (SDGs)

“…The most obvious form of habitat loss is the direct physical destruction of the habitats themselves upstream or downstream or in the surrounding area, and the loss of connectivity between them. The disruption of natural hydromorphological processes can moreover alter biotic and abiotic conditions that are vital for the natural ecosystem functioning, in some cases leading to the emergence of invasive species and evolution towards very different ecosystem components and processes [26]. In some of these cases, vectors responsible for the transfer of diseases can become more abundant due to a lack of predators [27].…”

Meta‐analysis shows that environmental DNA outperforms traditional surveys, but warrants better reporting standards

“…Categorical data for eDNA versus traditional methods were either based on results from the same study (83% of papers), or TA B L E 1 Types of traditional biodiversity surveys, which have been compared to eDNA method (Riascos et al, 2018) Blacklight traps (Maslo et al, 2017) Bottle trapping (Cai et al, 2017) Bottom trawling (Thomsen et al, 2012 Cast netting (Fujii et al, 2019) Dip netting (Fujii et al, 2019) Electrofishing (Fernández et al, 2019) Fungi fruiting body collection (Shirouzu et al, 2016) Fyke netting Gill netting (Gillet et al, 2018) Hand picking (Doi et al, (Lopes et al, 2017) Hydroacoustics (Coulter et al, 2018) Telemetry (Mize et al, 2019) F I G U R E 1 Workflow of this study consisted of three main steps: building paper database, extracting key information from papers, and conducting analysis of quantitative and categorical data a comparison made by the authors with historical traditional survey methods (17% of papers). Authors of comparative studies used three criteria: sensitivity, cost-effectiveness, and number of detectable species.…”

Detection and Control of Invasive Freshwater Crayfish: From Traditional to Innovative Methods

“…Alternatively, it may serve to confirm if an eradication plan has been effective in removing the target NICS. In the recent past, eDNA has been applied in a variety of studies for detecting invasive crayfish species, such as P. clarkii [28,74,75], Faxonius rusticus and P. leniusculus [71,73,76]. Crucial in eDNA studies are the sampling methods, in order to avoid contamination and to produce robust and repeatable eDNA results [77].…”

“…Advances in science and application of methodologies from other branches of biology have updated, and in some cases, transformed branches of research linked to the study of ecosystems and invasive species. Undoubtedly, aspects of self-cloning crayfish [25], the development of environmental DNA [26][27][28], studies on population genetics [29,30] and other approaches from molecular biology [31,32] have increased the limits of detection and expanded the knowledge on the route of spread and physiology of invasive species. Risk analysis and forecasting models along with focused surveillance have proven to foster efficient management actions [33].…”