The effects of water currents on walleye (Sander vitreus) eggs and larvae and implications for the early survival of walleye in Lake Erie

Abstract

Advection of teleost early life stages from nursery habitats can greatly impact year-class strength. Few studies test the effects of current on retention in freshwater fish eggs and larvae, so we used walleye (Sander vitreus) to assess current effects throughout egg and larval development and the role of substrate on egg retention. Eggs were removed from sand substrates at currents of 12 cm·s–1, but much higher speeds were required for removal from tile or stones. Larvae exhibited biphasic swimming ability, with slow swimming below 21 mm total length and rapidly increasing ability above 21 mm. These data necessitate adjusting models currently used to link water current and nursery advection in this and similar species, as the current effects were clearly substrate- and size-dependent.