2.3 | Environmental Data
We collected temporal, hydrological, and thermal conditions associated with each ichthyoplankton sample. We used Julian date to account for temporal variation in larval fish presence based on seasonal variation in spawning for each taxon, regardless of environmental conditions. Next, we acquired hydrological data from United States Geological Survey and United States Army Corps of Engineers gauging stations nearest each site (Supplemental data). We calculated average weekly river discharge (m3/s) and coefficient of variation (CV) of each sample to estimate the magnitude and variability in hydrological conditions prior to sampling. Finally, we calculated average and CV of weekly river temperature (°C) using linear regression for each tributary based on field water temperature observations compared to gauging station values (Supplemental data).