Modeling of transport processes of invasive carp eggs in channels and rivers*

We developed a stochastic egg drift model, SDrift, to study the transport processes of invasive carp eggs in rivers. SDrift is a Lagrangian particle tracking model that incorporates egg characteristics in water as a function of post-fertilization time and temperature. Turbulent velocities are simulated using the solution for the governing stochastic differential equation. We examined the longitudinal dispersion of simulated eggs in a variety of channels with an increasing complexity of river morphology, including a straight open channel, an idealized curved channel, and an 8-km reach in the Lower Missouri River. The hydrodynamics in the straight channel were constructed using classic flow and turbulence profiles in open channels. The hydrodynamics in the idealized curved channel and the river reach were determined using three-dimensional computational fluid dynamics simulations. In the river reach case, the simulations were calibrated with measured water surface elevation and validated with measured velocity distributions in 22 cross sections at two river discharges. The results show that the model can adapt to a wide range of mixing conditions, and reveal the effect of localized turbulence on egg retention and detention, which may have strong influences on the survival of fish.