Kokanee Spawning Ecology and Recruitment Response to Water Level Management in Lake Pend Oreille, Idaho Thesis uri icon

Overview

abstract

  • Thesis (M.S., Natural Resources) | Kokanee were the centerpiece of a productive commercial and recreational fishery in Lake Pend Oreille, Idaho for decades, before declining substantially in the late 1960s. The decline has been attributed to poor recruitment caused by a reduction in quality shoreline spawning habitat, which was linked to a hydropower-related shift to a lower minimum water level. This thesis evaluated the effects of habitat characteristics and water level on shore-spawning kokanee incubation success using a laboratory experiment, two in situ incubation studies, and a stock assessment model. All three incubation studies found that substrate size composition was a poor predictor of survival. The in situ studies found that kokanee eggs deposited at depths >10 m were viable and intragravel survival appeared to be enhanced by downwelling in habitat that was ostensibly poor. The egg box investigations and stock assessment model together suggested that water-level management is not an effective strategy for increasing the recruitment of shore-spawning kokanee.

publication date

  • December 15, 2013

has major professor

  • Quist, Michael  Associate Professor and Assistant Leader, Idaho Cooperative Fish and Wildlife Research Unit

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