Influence of growth, habitat, and density on emigration of coastal cutthroat trout (Oncorhynchus clarki clarki) from small streams, Prairie Creek Aquatics, Streelow Creek
Tussing SP. 2006. Influence of growth, habitat, and density on emigration of coastal cutthroat trout (Oncorhynchus clarki clarki) from small streams, Prairie Creek Aquatics, Streelow Creek. Humbold State University
From author's abstract: "Logistic regression models were used to explore which growth, density, and habitat attributes best explain downstream migration of coastal cutthroat trout (Oncorhynchus clarki clarki) within first and third order stream reaches of Prairie Creek, a small coastal stream in northern California. A total of 600 trout were tagged with passive integrated transponders in three watersheds, split evenly between the upper (first order) and lower (third order) stream reaches. For age 2+ trout from all reaches, relative condition factor the fall before spring migration best predicted migration with 69% correct classification. This result is largely attributable to the very high relative condition of non-migratory fish from upper reaches. The same models applied to solely lower reach data indicate that greater second and third year growth rates were primary determinants of migratory behavior correctly classifying 71% to 73% of trout. Models applied to upper reach data indicate that lower relative condition the fall before migration best explained migrants with 75% correct classification. A single phenotypically plastic response to developmental thresholds is not a sufficient explanation for migration at the sub-basin scale but is consistent with observed migratory relationships within reaches. Local adaptations to upper and lower reaches where greatest fitness is attained through different migratory life histories is a plausible explanation for migration being both a positive (higher growth rate) and negative (lower condition) developmental response. Differences in reach specific selective pressures and incomplete reproductive isolation through the long residence times of semi-permanent barriers (e.g. large woody debris) are consistent with this explanation."
- Type
- Academic
- Authors
- Tussing, Steven
- Date of Issue
- 2006-04
- Publisher
- Humbold State University
- Units
- REDW
- Keywords
- Anadromous Fish, Coastal Cutthroat Trout, Condition, Density, Distribution (Biodiversity), Ecology, Fish, Fish Ecology, Growth, Habitat, Migration, Modeling, Oncorhynchus clarki clarki, Prairie Creek, Prairie Creek Aquatics, Prairie Creek Bibliography, Presence (Biodiversity), Stream, Streelow Creek, Taxa Links To References, Thesis
- Subjects
- Ecological Framework: Biological Integrity | Focal Species or Communities | Fishes