Seasonal trends in eDNA detection and occupancy of bigheaded carps

Journal of Great Lakes Research
By: , and 

Links

Abstract

Bigheaded carps, which include silver and bighead carp, are threatening to invade the Great Lakes. These species vary seasonally in distribution and abundance due to environmental conditions such as precipitation and temperature. Monitoring this seasonal movement is important for management to control the population size and spread of the species. We examined if environmental DNA (eDNA) approaches could detect seasonal changes of these species. To do this, we developed a novel genetic marker that was able to both detect and differentiate bighead and silver carp DNA. We used the marker, combined with a novel occupancy model, to study the occurrence of bigheaded carps at 3 sites on the Wabash River over the course of a year. We studied the Wabash River because of concerns that carps may be able to use the system to invade the Great Lakes via a now closed (ca. 2017) connection at Eagle Marsh between the Wabash River's watershed and the Great Lakes' watershed. We found seasonal trends in the probability of detection and occupancy that varied across sites. These findings demonstrate that eDNA methods can detect seasonal changes in bigheaded carps densities and suggest that the amount of eDNA present changes seasonally. The site that was farthest upstream and had the lowest carp densities exhibited the strongest seasonal trends for both detection probabilities and sample occupancy probabilities. Furthermore, other observations suggest that carps seasonally leave this site, and we were able to detect this with our eDNA approach.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Seasonal trends in eDNA detection and occupancy of bigheaded carps
Series title Journal of Great Lakes Research
DOI 10.1016/j.jglr.2017.06.003
Volume 43
Issue 4
Year Published 2017
Language English
Publisher International Association for Great Lakes Research
Contributing office(s) Upper Midwest Environmental Sciences Center
Description 9 p.
First page 762
Last page 770