Length-Weight Relationship and Asymptotic Length for Lake Trout

The purpose of this modeling exercise was to provide Alaska-specific estimates of the length-weight relationship in lake trout, as well as the possible relationship between lake area and asymptotic weight, as a means to further refine the modeling framework described in Lester et al. (yyyy) for estimation of Maximum Sustained Yield of lake trout in Alaska.

Data were provided from [source??] and compiled by Region III biologists as relevant. Data represent a total of:

• 82 lakes
• 137 sampling events from 1960-2022
• 34,362 fish sampled
• 34,107 length measurements
• 3,894 weight measurements
• 3,887 paired length x weight measurements from
  • 24 lakes
  • 57 sampling events from 1960-2022

Repository contents

flat_data/

• lake_morphometry.csv gives lake-level data (area, latitude, etc)

• length_weight.csv gives fish-level data (length, weight, etc)

R/

• 1_laketrout_lwdata.R reads data and does some basic cleaning for the purpose of length-weight relationship

• 2_laketrout_lwmodels.R fits an exhaustive set of length-weight models (log-log regression), with all possible combinations of slope and intercept parameters:

  • common for all lakes
  • separate for all lakes but hierarchically distributed
  • trending with log-area
  • trending with latitude

Reference

Lester, et al. citation