Spawning surveys are the primary monitoring tool for monitoring bull trout and anadromous fish species in Oregon (Jacobs et al. 2009, Gallagher et al. 2007, Jacobsen et al. 2014,). Randomized redd counts are utilized to monitor steelhead escapement on coastal Oregon tributaries (Jacobsen et al. 2014).
Numerous studies of disparate salmonid species have shown positive significant relationships between redd counts and estimates of escapement (Gallagher et al. 2007), redd counts are strongly correlated with adult escapements (Dunham et al. 2001) and bull trout redd counts can detect a 50% decline in the population over 10 years (Howell and Sankovich 2012). However, redd counts can have significant sources of bias and error (Dunham et al. 2001), 5 year trends in redd counts can be misleading (Howell and Sankovich 2012) and redd counts should be conducted by experienced surveyors (Howell and Sankovich 2012, Muhlfield et al. 2006).Keyword Tags: