Dataset DOI: 10.5061/dryad.bzkh189q2

Description of the data and file structure

These data and code are associated with Canadian Journal of Fisheries and Aquatic Science manuscript ID cjfas-2025-0293 focused on examining the drivers between patterns of Brook Trout (BKT) occupancy between a historical period (1999-2004) and contemporary period (2022-2023) in central Idaho. Detailed methodologies are provided in the manuscript. Column headers in the first dataset (Voss_FieldProject_FinalDataset_FieldNamesForDryad.csv) correspond exactly to the names of covariates in the manuscript. The second dataset (Voss_FieldProject_FinalDataset.csv) is identical to the first, except that the column headers match those used in the R script (Voss2025_CJFAS_analysis.R); this is the CSV that should be imported into R. Finally, the third dataset (Voss_BLTxBKT_FieldProject_BKTdensities.csv) contains the brook trout densities used to create Figure 3 in the manuscript.

Files and variables

File: Voss_FieldProject_FinalDataset_FieldNamesForDryad.csv

Description: This is a reader-friendly version of the main dataset. Field names correspond exactly to the variable names in the accepted manuscript.

Variables

• SiteName: Name of sampling location
• RecoveryUnit: USFWS Bull Trout Recovery Unit
• CoreArea: USFWS Bull Trout Core Area
• huc10: Ten-digit hydrologic unit codes for watershed delineations provided by the national hydrography dataset
• SiteLength_m: Length of the site in m
• SampYear_h: Year in which the site was sampled during the historical period
• BKT_pres_hist: Denoting whether Brook Trout >= 70 mm were detected during the historical period
• SampYear_c: Year in which the site was sampled during the contemporary sampling period
• BKT_pres_contemp: Denoting whether Brook Trout >= 70 mm were detected during the contemporary period
• BKT_colonized: Denoting whether a historically unoccupied site was colonized by Brook Trout
• BKT_survived: Denoting whether a historically occupied site continued to be occupied by Brook Trout
• RBT: Denoting whether O. mykiss was present during the historical period
• M_BLT: Denoting the presence of a migratory Bull Trout life history during the historical period
• TEMP: Estimated historic mean August water temperature (C)

File: Voss2025_CJFAS_analysis.R

Description: This is the R script used to perform the analyses presented in this manuscript.

File: Voss_FieldProject_FinalDataset.csv

Description: This CSV is identical to Voss_FieldProject_FinalDataset_FieldNamesForDryad.csv, except that the variables retain their original names and are fully compatible with the R script Voss2025_CJFAS_analysis.R.

Variables

• SiteName: Name of sampling location
• SampYear_c: Year in which the site was resampled during the contemporary period.
• ReachLength_c: Length of the site in meters
• BKT_pres_c: Denoting whether Brook Trout >= 70 mm were (1) or were not (0) detected during the contemporary period
• BeaverDam: Denoting whether a beaver dam was present (p) or absent (a) during contemporary resampling
• SampYear_h: Year in which the site was sampled during the historical period
• BKT_pres_h: Denoting whether Brook Trout >= 70 mm were (1) or were not (0) detected during the historical period
• RBTpres_h: Denoting whether O. mykiss were (1) or were not (0) present during the historical period
• BKT_colonized: Denoting whether Brook Trout were (1) or were not (0) detected in a historically unoccupied site during contemporary resampling
• BKT_survived: Denoting whether Brook Trout were (1) or were not (0) detected in a historically occupied site during contemporary resampling
• BKT_abandoned: Denoting whether Brook Trout were (0) or were not (1) detected in a historically occupied site during contemporary resampling
• weighted_mean_ww_site: mean wetted width of the site using measurements collected during field sampling
• huc8: Name of 8-digit hydrologic unit code
• huc10: Name of 10-digit hydrologic unit code
• huc12: Name of 12-digit hydrologic unit code
• norwest_MeanAugTemp_hist_c: Estimated historic mean August water temperature (C)
• RecoveryUnit: USFWS Bull Trout Recovery Unit
• CoreArea: USFWS Bull Trout Core Area
• OnSite_slope_pct_new_noInt: Maximum–Minimum site elevation / site length (%)
• dist_to_nearest_SourcePop_km: Hydrologic distance between site i and nearest source population (km)
• prop_US_mtbs_high_burn: Proportion of upstream catchment burned by severe wildfire (1999–2023)
• S1_93_11_max: Highest norwest_MeanAugTemp_hist_c between site i and nearest source population (°C)
• VIC_MA_max: Highest annual mean daily discharge between site i and nearest source of Brook Trout (cfs)
• VLI_SLOPE_max: Highest upstream stream gradient between site i and nearest source of Brook Trout (%)
• BLT_gt400_pres_h_final: Denoting the presence of a migratory Bull Trout life history during the historical period

File: Voss_BLTxBKT_FieldProject_BKTdensities.csv

Description: 

Variables

• SiteName: Name of sampling location
• BKT_per_100m2: Estimated density of Brook Trout >= 70mm within the site, computed as the number of fish per 100 m^2

Code/software

Voss2025_CJFAS_analysis.R is compatible with R version 4.3.3; later versions and package updates may cause unforseen issues.

This code requires locally saved versions of Voss_FieldProject_FinalDataset.csv and Voss_BLTxBKT_FieldProject_BKTdensities.csv. All needed data imports, manipulations, summaries, and analyses are encoded in the annotated script therein.

Access information

Other publicly accessible locations of the data:

• None

Data was derived from the following sources:

• Idaho Department of Fish and Game, U.S. Forest Service, U.S. Bureau of Reclamation, and Idaho Cooperative Fish and Wildlife Research Unit (University of Idaho) datasets.