Effects of turbulence exposure on zebra mussel (Dreissena polymorpha) larval survival

Abstract

To more accurately predict recruitment of zebra mussels (Dreissena polymorpha) in waterbodies downstream of a source population, factors that control the successful transport of zebra mussel larvae need to be quantified. Turbulence has been identified in previous studies as a likely factor in larval morality in rivers and streams where turbulent energy dissipation can be orders of magnitude greater than in lakes. To investigate the impact of turbulent energy dissipation on zebra mussel larval mortality, we conducted a series of experiments using lake water collected from Lake Minnetonka, Minnesota containing veligers in a jar test device. Results indicate that zebra mussel larval mortality is a function of veliger size, turbulent energy dissipation, and exposure time. The mortality at 24 h of turbulence exposure was fit to a function of d^*, the ratio of shell size to Kolmogorov length scale, to develop a dose–response curve. Mortality rate constants were estimated by fitting mortality data from specified turbulence regimes to a first-order model. The mortality rates ranged from 0.09 to 1.71 day⁻¹ and were correlated to energy dissipation.