Bachelor of Science
School or Department
Forestry and Conservation
Wildlife Biology – Terrestrial
Faculty Mentor Department
Biological Sciences, Division of
Madison River, Flow, Aquatic invertebrates
Other Animal Sciences
Rising temperatures and anthropogenic influences threaten to alter aquatic ecosystems as oxygen supply and demand is altered depending on temperature, flow, and water presence. In late November of 2021, a dam malfunction occurred on the Madison River in Montana that caused the river to dry rapidly downstream of the dam and reduced flow by 70% for 50 hours. My experiments were designed to determine the effects of this event by assessing how long giant salmonfly nymphs (Pteronarcys californica) can survive in still water and in air depending on temperature and relative humidity. In the laboratory, we exposed salmonfly nymphs to four temperatures (5, 12.5, 20, and 25 ℃) in still water. We measured survival, feeding, and growth, as well as time spent performing ‘push-ups’ – a common respiratory movement that ventilates gills and increases oxygen supply rates. My study demonstrates that increases in temperature significantly increase the rate of pushups performed and decrease the survival of salmonfly nymphs. Next, we exposed nymphs to air – representing extreme dewatering – at five temperatures (5, 12.5, 20, 25, and 35 ℃) and two relative humidities (75% and 100%) to measure their survival. Survival times declined at higher temperatures, particularly in lower humidity, with an average survival of less than a day. Notably, the most significant factor influencing salmonfly survival was the type of medium they were in, as most of the nymphs in still water were able to survive the duration of the two weeks, while all the nymphs in air died.
Honors College Research Project
GLI Capstone Project
Todd, Kailie, "Effects of warming and drying on the survival and performance of giant salmonfly nymphs (Pteronarcys californica)" (2023). Undergraduate Theses, Professional Papers, and Capstone Artifacts. 449.
© Copyright 2023 Kailie Todd