Assessment of a new gear to sample walleye eggs

Abstract

A new gear for sampling walleye Sander vitreus eggs, egg sampling disks, is described, and the ability of these disks to estimate walleye egg density on mud, cobble, and rip-rap substrates is demonstrated. Each egg sampling disk was a concave steel disk covered with outdoor carpet. The ability of the disks to estimate walleye egg density and total egg deposition on a defined area was tested at Sherman Reservoir, Nebraska. The average cost of each egg sampling disk was US$8.00. An array of 10 disks could be processed (retrieved, complete the egg recovery procedure, and redeployed) in approximately 1 h. The egg sampling disks were an appropriate gear for estimating egg deposition on mud, cobble, and rip-rap substrate and could also be useful for estimating the total egg deposition of walleyes and other demersally spawning fish.