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Effect of brown trout body size on post‐stocking survival and pike predation
Author(s) -
Hyvärinen P.,
Vehanen T.
Publication year - 2004
Publication title -
ecology of freshwater fish
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 55
eISSN - 1600-0633
pISSN - 0906-6691
DOI - 10.1111/j.1600-0633.2004.00050.x
Subject(s) - pike , esox , brown trout , stocking , predation , trout , salmo , biology , fishery , hatchery , piscivore , fish <actinopterygii> , ecology , zoology , predator
– A total of 40 (20 age‐3 + 20 age‐4) radio‐tagged hatchery‐reared brown trout ( Salmo trutta L.) and 40 wild radio‐tagged northern pike ( Esox lucius L.) were released into a regulated river. Age‐3 brown trout were predicted and observed to be highly vulnerable to predation by pike (50% mortality), whereas age‐4 brown trout were predicted and observed to enjoy an almost absolute size refuge from predation (5% mortality). Almost half of the fish from both age groups similarly emigrated and survived from the river within 3 days of the release. However, there was a considerable difference in survival between age groups for fish that remained in the river for a longer period. Of these, all except one age‐3 brown trout were eaten by pike, whereas all but one age‐4 fish survived predation.