Using reverse-time egg transport analysis for predicting Asian carp spawning grounds in the Illinois River

• Published in: Ecological modelling 2018-09, Vol.384, p.53-62
• Main Authors: Zhu, Zhenduo, Soong, David T., Garcia, Tatiana, Behrouz, Mina Shahed, Butler, Steven E., Murphy, Elizabeth A., Diana, Matthew J., Duncker, James J., Wahl, David H.
• Format: Article
• Language: English
• Subjects: Asian carp; Egg dispersion; Egg drift; FluEgg; Illinois River; Reverse-time particle tracking; Spawning ground
• ISSN: 0304-3800; 1872-7026
• DOI: 10.1016/j.ecolmodel.2018.06.003

•An algorithm that back-casts spawning locations of Asian carp eggs was develop.•The algorithm was implemented into Fluvial Egg Drift Simulator program (FluEgg).•A case study was conducted using egg data collected from the Illinois River in 2015.•Tailwater section below the Locks and Dams appear to be preferred spawning locations.•The most upstream spawning location was in the upper Marseilles navigation pool. Identifying spawning grounds of Asian carp is important for determining the reproductive front of invasive populations. Ichthyoplankton monitoring along the Illinois Waterway (IWW) has provided information on abundances of Asian carp eggs in the IWW's navigation pools. Post-fertilization times derived from egg development stages and water temperatures can be used to estimate spawning times of Asian carp eggs, but estimating how far these eggs have drifted requires information on river hydraulics. A Fluvial Egg Drift Simulator (FluEgg) program was designed to predict the drift of Asian carp eggs in the riverine environment with egg growth considered. This paper presents a reverse-time particle tracking (RTPT) algorithm for back-casting the spawning location of eggs from their collection site. The RTPT algorithm was implemented as a module in FluEgg. The new version of FluEgg was coupled with an unsteady hydrodynamic model of the IWW to predict the spawning locations for 530 eggs that were collected in June 2015. The results indicate that tailwater sections below the Locks and Dams (L&Ds) in each navigation pool appear to be preferred spawning locations for Silver Carp (a species of Asian carp). From the data analyzed, the most upstream spawning location for the June 2015 spawning period was in the upper Marseilles navigation pool, downstream of the Dresden Island L&D. The RTPT algorithm can efficiently estimate spawning locations for multiple egg samples.