Date of Award:

5-2014

Document Type:

Thesis

Degree Name:

Master of Science (MS)

Department:

Watershed Sciences

Committee Chair(s)

Phaedra Budy

Committee

Phaedra Budy

Committee

John Shivik

Committee

Charles Hawkins

Abstract

Brook trout are native to the east and Midwestern United States. Brook trout have become a popular sport fish in the western United States and are currently widely stocked to provide sport fishing opportunities throughout the west. The Utah Division of Wildlife Resources (UDWR) regularly stocks brook trout into high mountain lakes in the Uinta Mountains to provide one of these popular fisheries. Stocking non-natives to high mountain lakes can cause competition with native species for food and habitat resources and provides source populations for dispersal of non-natives downstream. Triploid (sterile) fish may provide an opportunity to stock non-native fish to potentially sensitive environments like high mountain Uinta lakes. The UDWR stocked triploid and diploid (fertile) brook trout into nine lakes in the Uinta Mountains as a part of this study.

In this study, I examined the potential differences in growth and survival (relative performance) of stocked triploid and diploid brook trout. I also developed two models to explain the factors that may limit relative performance of stocked brook trout, independent of ploidy (triploid or diploid) level in high mountain Uinta lakes. I did not find any differences in relative performance of triploid compared with diploid brook trout based upon indices of diet, growth and survival. The models indicated that factors associated with lake size and fish density affected relative performance of stocked brook trout. Lakes with higher fish densities contained brook trout in poor condition versus lakes with lower fish densities. Additionally, smaller shallower lakes contained very few fish compared to larger deeper lakes of this study. These findings suggest that brook trout may survive better and grow larger if stocked at lower densities. The results also suggest that survival is low in small shallow lakes. Harsh over-winter conditions in high mountain Uinta lakes may provide an explanation of poor survival in these small shallow lakes. Results of this study provide evidence that triploid brook trout are a viable alternative to stocking diploid, fertile brook trout to diminish the potential negative effects of stocking a non-native species. This study also suggests an evaluation of the stocking regime in high mountain Uinta lakes in order to improve the size and survival of stocked brook trout.

Checksum

1e3ff8e79ff2a696cfa00b8f01b652e7

Download

Share

COinS

Copyright for this work is retained by the student. If you have any questions regarding the inclusion of this work in the Digital Commons, please email us at .