Putting Utilization Distributions to Good Use; a Novel Application of Static Interaction Modellng to Assess Space Use by White Sturgeon

We used static interaction analyses to determine if reproductively mature female white sturgeon Acipenser transmontanus responded to spawning habitat enhancement within a known spawning reach of the Kootenai River, Idaho, USA.  Fine-scale movements of white sturgeon were obtained with a telemetry positioning system during two spawning seasons; the first preceding placement of boulders within a discrete patch within the spawning area as a habitat enhancement feature and the second after placement of boulders.  Static interaction analysis was used to first evaluate fish space use of the area prior to enhancement and then to evaluate fish space use of the altered area.  Locations of mature female white sturgeon indicated avoidance of the area prior to enhancement and no association after enhancement, suggesting that spawning females were not attracted to the boulder patch.  This study showed the utility of a method for evaluating fish space use that is independent of measurements of microhabitat conditions and independent of indices of abundance.