Detecting the movement and spawning activity of bigheaded carps with environmental DNA.

Richard A Erickson,Christopher B Rees,Liza Walleser,Sunnie G Mccalla,Christopher M Merkes,Katherine F Touzinsky,Jon J Amberg,Alison A Coulter,Reuben R Goforth

doi:10.1111/1755-0998.12533

Richard A Erickson, Christopher B Rees + Show 7 more

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https://doi.org/10.1111/1755-0998.12533

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Abstract

Bigheaded carps are invasive fishes threatening to invade the Great Lakes basin and establish spawning populations, and have been monitored using environmental DNA (eDNA). Not only does eDNA hold potential for detecting the presence of species, but may also allow for quantitative comparisons like relative abundance of species across time or space. We examined the relationships among bigheaded carp movement, hydrography, spawning and eDNA on the Wabash River, IN, USA. We found positive relationships between eDNA and movement and eDNA and hydrography. We did not find a relationship between eDNA and spawning activity in the form of drifting eggs. Our first finding demonstrates how eDNA may be used to monitor species abundance, whereas our second finding illustrates the need for additional research into eDNA methodologies. Current applications of eDNA are widespread, but the relatively new technology requires further refinement.

Highlights

Invasive species adversely affect both ecosystem functions and economic activities by outcompeting native species, degrading habitats and decreasing the quality of recreational activities (Lockwood et al 2007; Pejchar & Mooney 2009; Simberloff et al 2013)
We found relationships among water discharge, environmental DNA (eDNA) and individual bigheaded carp movement that could be used to evaluate when spawning or other mass movements occur
We did not find a relationship between egg density and the other variables, which may be due to field sampling limitations or laboratory detection restrictions

Summary

Introduction

Invasive species adversely affect both ecosystem functions and economic activities by outcompeting native species, degrading habitats and decreasing the quality of recreational activities (Lockwood et al 2007; Pejchar & Mooney 2009; Simberloff et al 2013). Bigheaded carps (Hypophthalmichthys spp.), a subgroup of Asian carps, are invasive species that have aThese authors contributed to this work. Spread across North America via the Mississippi River system (Kolar & Lodge 2002). These species can outcompete native fishes (Irons et al 2007) and degrade habitat by changing both plankton communities (Sass et al 2014) and aquatic vegetation (Buck et al 2010). Several potential routes have been identified by which bigheaded carp may invade the Great Lakes (US Army Corps of Engineers 2010), including via the Wabash and Maumee Rivers through Eagle Marsh near Fort Wayne, IN, USA ( Eagle Marsh is scheduled to be closed in spring 2016; Jeff Heath, USACE, personal communication). While steps have been taken to help maintain separation at many of these possible invasion routes, species invasions may still be possible

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