Estimating drivers and identifying uncertainties in smallmouth bass population dynamics in an invaded river network

Smallmouth bass (Micropterus dolomieu) is an important recreational sportfish and destructive non-native species when introduced into freshwater habitats. There is therefore a need to understand the drivers of, and uncertainties in, smallmouth bass population dynamics for various management objectives. We combined long-term smallmouth bass catch-effort and early life history data from a non-native population in the Green River sub-basin of the upper Colorado River to develop a demographic model that links interannual variability in environmental conditions to recruitment in three river reaches. We used the model to quantify how hydrology, river temperature, and exploitation drive smallmouth bass population dynamics. Early life stages were influenced by timing of hatching and discharge. Dispersal of age-0 fish and density-dependent dynamics were identified as primary sources of uncertainty. Determining the true nature of density-dependent dynamics is important, as the impact of exploitat..., We compiled smallmouth bass catch-effort data collected by boat electrofishing during non-native removal efforts in the Yampa and Green rivers in 2005 through 2022 . We used catch data from the Lily Park, Yampa Canyon, and Middle Green River reaches.  Each spring and summer, multiple sampling trips were conducted in each reach. We defined a trip as a full sampling occasion comprised of multiple electrofishing passes from the top of the reach to the bottom. Sampling trips typically lasted 2 – 4 days. On most trips, counts of removed fish were summarized by three size classes (<100 mm, 100-200 mm, and >200 mm). Catch-effort data for each study reach were extracted from annual reports which have sampling details (Lily Park: Project # 125/98c, Yampa Canyon: Project # 110, Middle Green: Project # 123a) and are publicly available on the Upper Colorado River Endangered Fish Recovery Program website (https://coloradoriverrecovery.org/uc/documents/work-plan-documents/annual-reports/)...., , # Estimating drivers and identifying uncertainties in smallmouth bass population dynamics in an invaded river network

[https://doi.org/10.5061/dryad.76hdr7t5z](https://doi.org/10.5061/dryad.76hdr7t5z)

## Description of the data and file structure

This data and code describe the population dynamics of smallmouth bass in the Green River sub-basin of the Colorado River. Data included in the model include catch-effort data for electrofishing passes fit to an age structured model. Data included observed catch of adults (greater than 200 mm TL), sub-adults (100-200 mm), and age-0 (<100 mm) smallmouth bass in each reach, summarized and standardized predicted end of summer lengths of age-0 fish, discharge conditions during the hatch, the number of electrofishing passes during each sampling trip (effort), and index information for organizing catch by electrofishing pass, year, and reach in the population model. 

### Files and variables

#### File: data\_revision.zip

**Description:** Contai...,