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Gillnet selectivity for lake trout (Salvelinus namaycush) in Lake Superior

Canadian Journal of Fisheries and Aquatic Sciences

By:
, , , and
DOI:10.1139/f97-156

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Abstract

Gillnet selectivity for lake trout (Salvelinus namaycush) was estimated indirectly from catches in nets of 102-, 114-, 127-, 140-, and 152-mm stretch measure. Mesh selectivity was modeled as a nonlinear response surface that describes changes in the mean, standard deviation, and skewness of fish lengths across mesh sizes. Gillnet selectivity for lake trout was described by five parameters that explained 88% of the variation in wedged and entangled catches, 81% of the variation in wedged catches, and 82% of the variation in entangled catches. Combined catches of wedged and entangled lake trout were therefore described more parsimoniously than separate catches of wedged and entangled lake trout. Peak selectivity of wedged and entangled fish increased from 588 to 663 mm total length as mesh size increased from 102 to 152 mm, and relative selectivity peaked at a total length of 638 mm. The estimated lake trout population size-frequency indicated that gillnet catches were negatively biased toward both small and large lake trout. As a consequence of this bias, survival of Lake Superior lake trout across ages 9-11 was underestimated by about 20% when the catch curve was not adjusted for gillnet selectivity.

Additional publication details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Gillnet selectivity for lake trout (Salvelinus namaycush) in Lake Superior
Series title:
Canadian Journal of Fisheries and Aquatic Sciences
DOI:
10.1139/f97-156
Volume:
54
Issue:
11
Year Published:
1997
Language:
English
Publisher:
NRC Research Press
Contributing office(s):
Great Lakes Science Center
Description:
8 p.
First page:
2483
Last page:
2490
Online Only (Y/N):
N
Additional Online Files (Y/N):
N