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Turbidity‐Induced Changes in Reactive Distance of Rainbow Trout
Author(s) -
Barrett Jeffrey C.,
Grossman Gary D.,
Rosenfeld J.
Publication year - 1992
Publication title -
transactions of the american fisheries society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.696
H-Index - 86
eISSN - 1548-8659
pISSN - 0002-8487
DOI - 10.1577/1548-8659(1992)121<0437:ticird>2.3.co;2
Subject(s) - rainbow trout , turbidity , foraging , trout , environmental science , sediment , fish <actinopterygii> , predation , fishery , biology , ecology , paleontology
We used artificial stream channels to conduct feeding trials with wild rainbow trout Oncorhynchus mykiss at three levels of suspended sediment. To examine the effects of turbidity on reactive distance and pursuit speed, we fed rainbow trout (87–185 mm standard length) pieces of mealworms Tenebrio sp. as test prey. A video camera system was used to record the pursuit speed and reactive distance of fish during foraging bouts. Turbidity had a consistent and negative effect on reactive distance (analysis of variance, P < 0.05). On average, reactive distances in the 15‐ and 30‐NTU (nephelometric turbidity units) treatments were only 80% and 45%, respectively, of those observed at ambient turbidities (4–6 NTUs). By contrast, turbidity did not significantly affect pursuit speed. Pursuit speed varied greatly among individuals but was similar for each fish across turbidity levels. These results indicate that sediment‐producing activities, such as logging and road building, could reduce foraging success within trout populations.