Habitat metrics to assess the behavior of white sturgeon in a regulated river /by Shaun K. Parkinson.

White sturgeon is one of several species-of-concern affected by hydropower operations in the north-west of the United States. Juveniles are thought to be a vulnerable life-stage of sturgeon, although in general little is known about this ancient species that can live more than 100 years and grow to over 6m in length. White sturgeon used to be anadromous, but are now land-locked and their range has become fragmented due to the construction of large dams during the past century throughout the Columbia Basin. Recent advances in telemetry technologies providing information on individual location and metabolic rates are combined with high resolution hydrodynamic modeling to provide a detailed picture of how sturgeon respond to a regulated flow regime in a confined study reach on the Snake River through Hells Canyon. The conditions studied were sustained low flows, sustained high flows and diurnal fluctuating flow conditions caused by varying demand for hydroelectric power. Traditional indices used in aquatic habitat modeling based on velocity and depth fail to capture the behavior of the juvenile fish. The data from this field study allowed 31 separate parameters of meso- and micro-scale habitat to be evaluated. The fish are shown to select locations in the river that maximize the potential for drift food consumption while minimizing the energy expenditure necessary to maintain that position. This approach reduced the errors in expected fish location by a factor of 2 over the traditional aquatic habitat modeling approach. The analytical solutions obtained for the maximum flux of potential drift food over the depth and measures of energy expenditure offer parameters that may be useful for assessing other species in regulated rivers.Thesis (Ph. D., Civil Engineering)--University of Idaho, 2007