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Interaction of sauger Sander canadensis and walleye Sander vitreus in a large, shallow northern river
Author(s) -
Haxton Tim,
Friday Mike
Publication year - 2019
Publication title -
journal of fish biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.672
H-Index - 115
eISSN - 1095-8649
pISSN - 0022-1112
DOI - 10.1111/jfb.14080
Subject(s) - biology , interspecific competition , sander , abundance (ecology) , ecology , range (aeronautics) , competition (biology) , fishery , mechanical engineering , materials science , engineering , composite material
The objectives of this study were to: (1) determine the relative abundance of sauger Sander canadensis and walleye S. vitreus within the Rainy River using a standardized index netting technique; (2) assess the life‐history characteristics of the two species in a northern river; (3) examine the spatial distribution of the two species; (4) assess year‐class synchrony. At a larger scale, relative abundance of S. canadensis and S. vitreus were similar among sections of the river. However, at a finer scale, S. canadensis were the dominant species over more area (24%) of the river than S. vitreus (12%). Life‐history traits for both species were within the range reported for North American. Mortality rates were similar, suggesting that anglers were not affecting one species more than the other. Year‐class strengths were not synchronous between S. canadensis and S. vitreus ( r = 0.07). There was evidence of S. canadensis potentially outcompeting S. vitreus with a strong year class of S. canadensis followed by a very weak class of S. vitreus . Additionally, S. canadensis were larger than S. vitreus in most sections of the river when adjusted for mean size. However, the potential interspecific competition was not to the exclusion of S. vitreus . Turbidity was probably the factor that enable S. canadensis to survive sympatrically with S. vitreus given their inability to segregate by depth within the river.