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Lake trout population modeling and annual assessment of suppression netting

Duration

September 2016 - August 2021

Narrative

- The Native Fish Conservation Plan specifies that the goal for lake trout suppression is to reduce lake trout population growth rate to 0.85 for 10 years (secondary desired outcome). Thus, lake trout catch per unit effort (C/f) in distribution netting (i.e., assessment netting) will decrease 15% per year to 0.1 fish per 100-m net night if suppression is successful. The goal for Yellowstone cutthroat trout abundance is to increase C/f above 10.

Annual distribution netting conducted by the National Park Service is a prerequisite for assessing population metrics. Data from distribution netting will be used to estimate temporal change in C/f using linear models and paired t-tests. Distribution netting data will be used to estimate size structure for Yellowstone cutthroat trout and lake trout using length-frequency histograms and cumulative-frequency distributions. Lake trout and Yellowstone cutthroat trout age data collected by the National Park Service will be used to create an age-length key to estimate age structure and total annual mortality will be estimated using catch curves. Lake trout total annual mortality will be converted to an estimate of exploitation (Miranda and Betolli 2007). Exploitation represents the fraction of the population being removed; therefore, lake trout abundance will be reconstructed by dividing total catch by the exploitation rate (Syslo et al. 2011). Reconstructed population estimates for will be evaluated for trend (Syslo et al. 2011).

 

Current Staff

Federal Staff: 2

Masters Students: 15

Phd Students: 2

Post Docs: 0

University Staff: 3

5 Year Summary

Students graduated: 16

Scientific Publications: 26

Presentations: 47

 

Personnel

Funding Agencies

  • Yellowstone National Park

Links

Montana Cooperative Fishery Research Unit Cooperators

  1. Montana Department of Fish, Wildlife and Parks
  2. Montana State University
  3. U.S. Geological Survey