Abstract
As the use of environmental-DNA (eDNA) expands as a method to detect the presence and quantity of aquatic taxa, factors potentially impacting the efficacy of this technique must be investigated. Many studies have examined the effects of abiotic parameters on the degradation of environmental-DNA (e.g. UV radiation, pH, temperature, etc.), however, few have focused on biotic effectors. Through high-filtering rates coupled with dense colonization, Asian clams (Corbicula fluminea) are able to drastically alter the quantity of particulate matter through translocation into the sediment, potentially including sources of eDNA in lotic and lentic systems. Using a longitudinal, laboratory experiment, we tested the effect of varying densities of Asian clams on the translocation rate of common goldfish (Carassius auratus) DNA. Target DNA in testing tanks was quantified through quantitative PCR (qPCR) at regular intervals and compared. Tanks housing the highest density of Asian clams produced significantly lower DNA concentrations over time compared to tanks of lower densities. These results show, for the first time, a density-dependent reduction of local eDNA sources by bivalve filtration that may lead to the obstructed detection of target species through the sampling of eDNA. Based on these findings, we recommend highly concentrated bivalve populations be taken into consideration when choosing the time and locality of eDNA sampling efforts.
Highlights
One of the first steps in conserving imperiled taxa is to gain a better understanding of their distributions and abundances [1]
The model testing the effect of varying clam densities on environmental DNA (eDNA) concentrations produced significant interaction terms such that high-density tanks decreased by 0.134 (+/-0.0666 confidence interval (CI)), 0.139 (+/-0.0689 CI), and 0.11007 (+/-0.07101 CI) more cycle threshold (CT)-units per hour than control, low and medium density tanks respectively (p = 0.000152, 0.000142, & 0.0029)
No collection or extraction controls were successfully amplified by quantitative PCR (qPCR), thereby indicating that no cross contamination of target DNA occurred in the field or laboratory setting
Summary
One of the first steps in conserving imperiled taxa is to gain a better understanding of their distributions and abundances [1]. The difficulty of conserving imperiled taxa, is contingent upon the taxa in question, its abundance, and its respective habitat [2]. Sampling for aquatic individuals with low populations in large systems can often make gathering necessary distribution and abundance data challenging and/or impractical. A relatively new technique to assist with these issues is the collection and use of aquatic environmental DNA (eDNA).
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
