Methods:
Sampling sites:
In collaboration with other UMBS faculty and researchers, before dam removal, we selected three sites in the Maple River below the (former) dam where joint physical and biological data were collected. Our three downstream, 100-m reference sites along the main Maple River below Lake Kathleen were sampled in June/July both before and after dam removal. Our upcoming sampling year (2023) occurs five years post dam removal. In addition to our mainstem sites, in 2019 (the first summer post dam removal) we added two additional sites above the dam at the former site of Lake Kathleen. These sites are each 100 meters in length and have been sampled once per summer since 2019 with the exception of the summer of 2022.
Fish abundance:
We will collect fish abundance data via two-pass electrofishing using paired, backpack electrofishers (Smith Root, WA) to collect fishes. All fishes will be held separately by pass in shaded coolers with air stones until both passes are completed. Once electrofishing is completed, fishes will be identified to species, enumerated, and all individuals in the Salmonid family will be measured to the nearest millimeter. Fish will then be released. If we are unsure of a species identification, a voucher specimen will be collected for identification in the lab.
Fish habitat use:
All five sites will be sampled by snorkeling on two separate occasions. Two pairs of one snorkeler and one buddy/recorder will slowly move upstream in tandem. The snorkeler will identifu and estimate the length of all salmonids and note other species. Microhabitat data including stream velocity, substrate, depth, and fish depth will be recorded at the salmonid focal point (tip of the nose).
