Slide 1
Project Objective
Develop an empirically based modeling approach to quantify the effects of environmental variables on distribution of the two ecotypes in the Yakima Basin
Key Concepts
O. mykiss are phenotypically plastic
Interbreeding between ecotypes occurs
Cross-ecotype production occurs
Rainbow trout populations can give rise to anadromous populations and vice versa
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Key Model Components
Summary of Model Functions
Daily growth
Flow and temp effects on freshwater survival
Summer carrying capacity
Over-winter survival
Size-dependent marine survival
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Spatial Structure
Modeling Effects of Flow on Carrying Capacity
Modeling Growth in Freshwater
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Age-Dependent Resident Maturation
Fecundity vs Body Size
Cross-Ecotype Production
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Conclusions
Distribution of ecotypes appears to be a function of flow and temperature conditions, stream size and population location within the watershed.
Increases in flow and decreases in stream temperature during summer create conditions that favor a resident life-history.
Tributaries represent the best opportunity for increased production of anadromous
O. mykiss
in the Yakima Basin.
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