Vol. 43 (2020)
Research Project Ecology

Developing a baseline understanding of gill lice distribution, prevalence, and infestation intensity in the Upper Snake River Watershed

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  • William Fetzer,
  • Robert Al-Chokhachy,
  • Jeff Baldock,
  • Clark Johnson,
  • Diana Miller,
  • Annika Walters,
  • Chad Whaley
William Fetzer
Assistant Professor, Department of Zoology and Physiology, University of Wyoming, Laramie, WY
Robert Al-Chokhachy
Research Fisheries Biologist, Northern Rocky Mountain Science Center, United States Geological Survey, Bozeman, MT
Jeff Baldock
PhD Student, Department of Zoology and Physiology, University of Wyoming, Laramie, WY
Clark Johnson
Fisheries Biologist, Wyoming Game and Fish Department, Jackson, WY
Diana Miller
Fisheries Biologist, Wyoming Game and Fish Department, Jackson, WY
Annika Walters
Assistant Unit Leader, Wyoming Cooperative Research Unit, United States Geological Survey and Associate Professor, Department of Zoology and Physiology, University of Wyoming, Laramie, WY
Chad Whaley
Fisheries Biologist and Aquatic Invasive Species Coordinator, Grand Teton National Park, Moose, WY
a wide river bend among pine trees underneath a cloudy sky

Published 2020-12-15

Abstract

Climate change is altering temperature, precipitation, and snowpack dynamics, which will affect aquatic ecosystem thermal and flow regimes. Pathogens are an emerging threat that also has the potential to interact with climate change to affect fish population dynamics. Our research addresses: 1) What species of gill lice are present within the USR, 2) What is their distribution, prevalence, and infection intensity, and 3) Does gill lice infestation negatively affect metrics of fish condition? During 2020 and 2021, our team observed gill lice on 307 out of 7,255 fish inspected. Of twelve species inspected, gill lice were only observed on Snake River Cutthroat Trout and Mountain Whitefish. Our preliminary results suggest that the current distributions of gill lice within USR is primarily limited to the Snake River and immediately adjacent tributaries and infection prevalence and intensity remain low. While conditions in the USR have not reached the level of concern observed in other locations, a greater understanding of what factors could increase the extent and intensity of gill lice is needed to develop management strategies to improve the resilience of fish populations and communities to multiple stressors, including climate change, non-native species, and emerging pathogens.

 

Featured photo by Yellowstone National Park on Flickr (https://flic.kr/p/2h6Zmfw).

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