Oral Presentations
Presentation Type
Presentation
Faculty Mentor’s Full Name
Art Woods
Faculty Mentor’s Department
Division of Biological Sciences
Abstract / Artist's Statement
This study examines how warming and drying affect the performance and survival of giant salmonfly nymphs (Pteronarcys californica), which are important economically, ecologically, and culturally throughout the mountain west. My experiments were motivated by a dam malfunction that occurred in late November 2021 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. The effects of such events on aquatic insects are unknown, and my experiments were designed to assess how long salmonfly nymphs could survive in still water as well as in air depending on temperature and relative humidity. For the first portion of my study, I exposed salmonfly nymphs in the laboratory to four temperatures (5, 12.5, 20, and 25 ℃) in still water. I then measured survival, feeding, and growth, as well as a behavior called ‘push-ups’ – a stereotypic respiratory movement that ventilates gills and increases oxygen supply rates. My study demonstrates that temperature has a significant effect on the rate of pushups performed and the survival of salmonfly nymphs. The results for feeding and growth were not significant. In the second part of my study, I exposed nymphs to dry conditions – representing extreme dewatering – at five temperatures (5, 12.5, 20, and 25 ℃) and two relative humidities (75% and 100%) and measured how long they survived. Temperature and humidity influenced survival; survival times declined at higher temperatures and were especially short in the lower humidity. Regardless no salmonfly survived outside of water longer than four days at either humidity. However, 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 of the nymphs in air died.
Category
Life Sciences
Effects of warming and drying on the survival and performance of giant salmonfly nymphs (Pteronarcys californica)
UC 330
This study examines how warming and drying affect the performance and survival of giant salmonfly nymphs (Pteronarcys californica), which are important economically, ecologically, and culturally throughout the mountain west. My experiments were motivated by a dam malfunction that occurred in late November 2021 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. The effects of such events on aquatic insects are unknown, and my experiments were designed to assess how long salmonfly nymphs could survive in still water as well as in air depending on temperature and relative humidity. For the first portion of my study, I exposed salmonfly nymphs in the laboratory to four temperatures (5, 12.5, 20, and 25 ℃) in still water. I then measured survival, feeding, and growth, as well as a behavior called ‘push-ups’ – a stereotypic respiratory movement that ventilates gills and increases oxygen supply rates. My study demonstrates that temperature has a significant effect on the rate of pushups performed and the survival of salmonfly nymphs. The results for feeding and growth were not significant. In the second part of my study, I exposed nymphs to dry conditions – representing extreme dewatering – at five temperatures (5, 12.5, 20, and 25 ℃) and two relative humidities (75% and 100%) and measured how long they survived. Temperature and humidity influenced survival; survival times declined at higher temperatures and were especially short in the lower humidity. Regardless no salmonfly survived outside of water longer than four days at either humidity. However, 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 of the nymphs in air died.