Figure 3. Location and number of white sturgeon spawning events, Kootenai River near Bonners Ferry, Idaho, 1994–2001. Spawning data provided by Idaho Department of Fish and Game, written commun., 2005. Spawning event per unit effort (SEPUE) is the number of times fertilized eggs were detected on an egg mat resting on the riverbed at a sampling site divided by the time the mat was deployed. Egg mats were retrieved, examined, and replaced every 24 to 48 hours.