Tracking Brown Trout (Salmo trutta) in the Little Juniata River: the Undergraduate Experience
Start Date
13-11-2015 8:00 PM
End Date
13-11-2015 9:59 PM
Description
The objective of our study is to identify factors that influence the movement of brown trout (Salmo trutta) in the Little Juniata River. Brown trout are a non-native species popular in Pennsylvania for recreational sport fishing. The Little Juniata River is a tributary of the Juniata River in the Susquehanna River watershed and is 51.7 km-long. The optimal water temperature range for brown trout is between 12°-19°C; temperatures of 27°C and higher are lethal. Stretches of the Little Juniata regularly exceed 27°C each summer. To track their movement, we surgically implanted Lotek MST930MT transmitters into fish starting in March 2015. We selected fish that were 13 inches or greater (about 340g) because the transmitter had to weigh less than 2% of the body weight of the fish. The initial goal of the study was to investigate where brown trout moved during these lethal periods. The battery life of the transmitter is approximately 400 days, so we have expanded the study to determine other factors that could influence the movement of these fish including storm events, low flow, spawning season, low temperature. Depending on ease of access and flow conditions, we drove, kayaked, or walked a 32 km stretch of the river to locate the tagged fish. Our preliminary results show that under optimal water temperatures and high flow, fish movement was primarily driven by storm events. Storm events were also associated with high turbidity and higher fecal coliform counts. Dissolved Oxygen, pH, and conductivity did not change significantly. In August, high temperatures and low flows were associated with movement of fish. We will continue data collection until the batteries of the transmitters fail. Our sample size is relatively small (24 fish) so we plan to increase our sample size next spring to improve the robustness of our results. Another finding that we would like to explore is the cause of detached transmitters. While we did not have mortality associated with surgery, we did find transmitters that had somehow been detached from the fish. We think it likely that these transmitters have been expelled by the fish through the body wall. We plan to test this theory by implanting mock transmitters on hatchery fish.
Type
Poster
Language
eng
Tracking Brown Trout (Salmo trutta) in the Little Juniata River: the Undergraduate Experience
Elaine Langone Center, Terrace Room
The objective of our study is to identify factors that influence the movement of brown trout (Salmo trutta) in the Little Juniata River. Brown trout are a non-native species popular in Pennsylvania for recreational sport fishing. The Little Juniata River is a tributary of the Juniata River in the Susquehanna River watershed and is 51.7 km-long. The optimal water temperature range for brown trout is between 12°-19°C; temperatures of 27°C and higher are lethal. Stretches of the Little Juniata regularly exceed 27°C each summer. To track their movement, we surgically implanted Lotek MST930MT transmitters into fish starting in March 2015. We selected fish that were 13 inches or greater (about 340g) because the transmitter had to weigh less than 2% of the body weight of the fish. The initial goal of the study was to investigate where brown trout moved during these lethal periods. The battery life of the transmitter is approximately 400 days, so we have expanded the study to determine other factors that could influence the movement of these fish including storm events, low flow, spawning season, low temperature. Depending on ease of access and flow conditions, we drove, kayaked, or walked a 32 km stretch of the river to locate the tagged fish. Our preliminary results show that under optimal water temperatures and high flow, fish movement was primarily driven by storm events. Storm events were also associated with high turbidity and higher fecal coliform counts. Dissolved Oxygen, pH, and conductivity did not change significantly. In August, high temperatures and low flows were associated with movement of fish. We will continue data collection until the batteries of the transmitters fail. Our sample size is relatively small (24 fish) so we plan to increase our sample size next spring to improve the robustness of our results. Another finding that we would like to explore is the cause of detached transmitters. While we did not have mortality associated with surgery, we did find transmitters that had somehow been detached from the fish. We think it likely that these transmitters have been expelled by the fish through the body wall. We plan to test this theory by implanting mock transmitters on hatchery fish.