Methods

Data collection

The study area lies in the Albertan Rocky Mountain foothills and includes 8 headwater streams located in both the Red Deer River and North Saskatchewan River watersheds. The headwater streams sampled were North Burnt Timber, Elk, Rocky, Rough, Trout, Wilson, Wildhorse, Yara. Sampling occurred in July and August of 2020 and 2021. All streams were sampled for aquatic invertebrates using three-minute kick sampling with fine mesh D-nets. Separate kick samples were completed in riffles, pools, and runs at each site so that up to three kick samples were done at each site. This was done to ensure a fair representation of invertebrates from each stream. The number of sites completed on each stream is dependent on electrofishing results and therefore site numbers vary between streams. The kick samples were frozen in the field and brought back to the lab where the invertebrates were then identified down to the family level according to Clifford (1991). Where family level could not be identified, invertebrates were identified to the nearest taxonomic level. Finally, the data was entered into a table based on their family and site. Standardized electrofishing sampling was conducted in all the streams, however, not all sampled streams showed any signs of any of the three trout species in question and will as a result not be considered for this project.

Data Analysis

The analysis for this project was based on measuring correlation between the total beta diversity of aquatic invertebrates and the abundance of trout, as well as between the components of beta diversity, replacement and nestedness, and trout abundance. Trout abundance was broken down into total trout abundance as well as into each of the three species. This analysis was conducted via the use of residual plots and regression analysis. In order to determine if other factors were influencing the results, this analysis was also done for the alpha diversity of aquatic invertebrates and trout abundance, as well as for aquatic invertebrate abundance and trout abundance.

The data analysis was completed in R version R.4.1.1 utilizing the ggplot2 package.