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 article 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. If you use these data or code, please cite the article:

Voss, N. S., Bowersox, B. J., Nolfi, D. C., and Quist, M. C. 2026. Patterns of recent brook trout invasion in bull trout streams in relation to habitat, source connectivity, biotic resistance, and disturbance. Canadian Journal of Fisheries and Aquatic Sciences 83:1-15.

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.