Response to Technical Assistance Request #1096: Mitigate threats to native amphibian populations from exotic bullfrogs in Salt Wash and Courthouse Wash, Arches National Park
Medley CN. 2017. Response to Technical Assistance Request #1096: Mitigate threats to native amphibian populations from exotic bullfrogs in Salt Wash and Courthouse Wash, Arches National Park. WRD/Fish Program. Fort Collins, CO
In 2012, ARCH submitted a Technical Assistance Request (TAR 1096, Appendix 1) to the Biological Resources Division (BRD) of the Natural Resource Stewardship and Science Directorate (NRSS) requesting recommendations on how to control non-native bullfrogs in ARCH to reduce presumed predation on decreasing native amphibian populations. Upon an initial review of the TAR (Appendix 2; May 29th, 2013) by the Fish Program of the Water Resources Division (WRD), it was suggested that the presence of non-native fish could also be a major cause of reduced native amphibian populations via predation on juvenile aquatic life stages. Previously, on June 16, 2010, fisheries biologists from WRD (John Wullschleger, Nic Medley) observed numerous non-native “bullhead” in the ponded area of Salt Wash, upstream of the park road bridge, in the vicinity of Wolfe Ranch. These taxa are known to be voracious predators of aquatic organisms. The presence of bullhead had not previously been documented at this location indicating that the distribution of fishes had changed in the 27 years since the last fish survey (Webb 1988). Consequently, to better understand the possible relationship between low amphibian abundance and the presence of potential non-native predators within the park, it was recommended that a combined fish and amphibian survey be conducted in the two major perennial drainages of ARCH.
- Type
- Technical Assistance Report
- Authors
- Medley, Carl
- Date of Issue
- 2017-03-02
- Publisher
- WRD/Fish Program
- Units
- ARCH
- Keywords
- Amphibians, bullfrogs, Fish, native, non-native, otter, roundtail chub, speckled dace
- Subjects
- Ecological Framework: Biological Integrity | Focal Species or Communities | Fishes , Ecological Framework: Biological Integrity | Focal Species or Communities | Amphibians and Reptiles