Event Title

Exotic Crayfish Removal from Red Butte Reservoir, Utah

Location

Space Dynamics Laboratory

Event Website

http://water.usu.edu/

Start Date

3-25-2004 10:50 AM

End Date

3-25-2004 11:00 AM

Description

Red Butte Reservoir is a small (8.75 acres) impoundment currently used as a refugia for threatened and endangered, native fish. The Northern crayfish, Orconectes virilis, was introduced (probably by fishermen) in the late 1990’s. Since the appearance of this crayfish, there has been a significant increase in turbidity as well as loss of most macrophytes. There is concern that this introduction will negatively affect the endangered fish community that has thrived so well due to limnological and food web changes. In the summer of 2003, we attempted to identify potential mechanical control methods to decrease or eradicate the crayfish. An initial population estimate of 7,381 (± 1,100) was obtained by using a mark-recapture technique (based on 1,357 marked individuals). After this initial estimate, we removed 3,932 unmarked crayfish throughout the summer. We then performed another mark-recapture estimate and found the final population to be 11,660 (± 2,089) crayfish. Our removal methods were not successful, undoubtedly due to reproduction that occurred throughout our effort.

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Mar 25th, 10:50 AM Mar 25th, 11:00 AM

Exotic Crayfish Removal from Red Butte Reservoir, Utah

Space Dynamics Laboratory

Red Butte Reservoir is a small (8.75 acres) impoundment currently used as a refugia for threatened and endangered, native fish. The Northern crayfish, Orconectes virilis, was introduced (probably by fishermen) in the late 1990’s. Since the appearance of this crayfish, there has been a significant increase in turbidity as well as loss of most macrophytes. There is concern that this introduction will negatively affect the endangered fish community that has thrived so well due to limnological and food web changes. In the summer of 2003, we attempted to identify potential mechanical control methods to decrease or eradicate the crayfish. An initial population estimate of 7,381 (± 1,100) was obtained by using a mark-recapture technique (based on 1,357 marked individuals). After this initial estimate, we removed 3,932 unmarked crayfish throughout the summer. We then performed another mark-recapture estimate and found the final population to be 11,660 (± 2,089) crayfish. Our removal methods were not successful, undoubtedly due to reproduction that occurred throughout our effort.

https://digitalcommons.usu.edu/runoff/2004/AllPosters/15