Bull trout (<em>Salvelinus confluentus</em>) telemetry and associated habitat data collected in a geodatabase from the upper Boise River, southwestern Idaho

Abstract

For an overview of USGS information products, including maps, imagery, and publications, visit http://store.usgs.gov. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this information product, for the most part, is in the public domain, it also may contain copyrighted materials as noted in the text. Permission to reproduce copyrighted items must be secured from the copyright owner.

Thermal heterogeneity, migration, and consequences for spawning potential of female bull trout in a river–reservoir system

“…Of the remaining 25 fish with contents in their stomachs, fish made up the largest percentage (98%) by weight of the dietary contents and was dominated by yellow perch ( Perca flavescens ) and salmonids (Salmonidae). Bull trout appeared to track the fish species with greater relative abundance (MacCoy et al, 2017), which is similar to bull trout in other systems (Beauchamp & Van Tassell, 2001; Fraley & Shepard, 1989; Lowery & Beauchamp, 2015). Based on data from the diet contents and quarterly fish surveys from 2011 to 2014 (MacCoy et al, 2017), we estimated a range of energy densities from approximately 4,000 J/g to 6,000 J/g, which include fish and invertebrates (Beauchamp & Van Tassell, 2001; Hanson et al, 1997).…”

“…To evaluate the migratory behaviors displayed by bull trout in the Boise River basin, we used previous telemetry observations (Flatter, 2000; MacCoy, Shephard, Benjamin, Vidergar, & Prisciandaro, 2017; Maret & Schultz, 2013; Monnot et al, 2008; Salow & Hostettler, 2004). Most migratory bull trout overwinter (October to March) in Arrowrock Reservoir, return to the MF or NF Boise River between March and July, remain in the headwaters until fall spawning, and then return to Arrowrock Reservoir.…”

“…Bull trout appeared to track the fish species with greater relative abundance (MacCoy et al, 2017), which is similar to bull trout in other systems (Beauchamp & Van Tassell, 2001; Fraley & Shepard, 1989; Lowery & Beauchamp, 2015). Based on data from the diet contents and quarterly fish surveys from 2011 to 2014 (MacCoy et al, 2017), we estimated a range of energy densities from approximately 4,000 J/g to 6,000 J/g, which include fish and invertebrates (Beauchamp & Van Tassell, 2001; Hanson et al, 1997). To account for uncertainty in the quality of the prey being consumed, in model simulations we randomly assigned daily prey energy density using a normal distribution (Mean = 5,000 J/g; SD = 1,270 J/g).…”

“…Some bull trout occupied more than one water segment (e.g., upper and lower SF Boise River; different arms of Arrowrock Reservoir). We attempted to estimate P Cmax by sections of the watershed based upon migration timing of radio‐tagged fish (MacCoy et al, 2017). We estimated mean P Cmax for Arrowrock Reservoir ( P Cmax = 0.26; SD = 0.14; n = 6), for SF Boise River (mean P Cmax = 0.22; SD = 0.05; n = 4), and for MF Boise River (mean P Cmax = 0.19; assumed SD = 0.05; n = 1).…”

“…On average, timing of upstream migration to spawning grounds was on 01 June. Downstream migration was on 01 October (sensu MacCoy et al, 2017; Monnot et al, 2008).…”