Environmental variables influencing downstream migration of juvenile coho salmon (Oncorhynchus kisutch) in three Northern California streams
Feola JE. 2007. Environmental variables influencing downstream migration of juvenile coho salmon (Oncorhynchus kisutch) in three Northern California streams. Humboldt State University, Natural Resources: Fisheries
Author's abstract: The primary objective of this study was to study the migration of coho salmon (Oncorhynchus kisutch) smolts in three coastal streams to determine if the probability of migration was correlated with environmental variables. Streams studied were Boyes, Streelow and Prairie Creeks, all located in Redwood National and State Parks, Humboldt County, California during 1999-2003. Smolt migration data consisted of daily catches from fyke net traps operated from 2 March to 6 June each year. Environmental variables included in models included: year, day of year, water temperature, change in water temperature, cumulative degree-days, discharge, change in discharge, lunar cycle, and the interactions of these variables. A partial logistic model using linear stepwise regression was used for analysis of environmental variables affecting coho salmon smolt movement. Akaike’s Information Criterion and Bayes statistics were used to select the best models. In Boyes Creek, the significant (p < 0.05) variables included within the best model were: year, day of year, day of year2, discharge, change in discharge, the interaction of day of year and discharge, the interaction of day of year and change in discharge and the interaction of water temperature and discharge. In Streelow Creek, the significant (p < 0.05) variables included within the best model were day of year and the interaction of day of year and water temperature. In Prairie Creek, the significant (p < 0.05) variables included within the best model were: day of year, discharge, water temperature, degree-days and the interaction of day of year and discharge. Another objective of this study was to evaluate the use of PIT (passive integrated transponder) tag antennae in measuring downstream migration of coho salmon smolts during the 2003 smolt migration. The pit tag antennae detected 96% of the pit tagged fish that moved past the antennae into live boxes. Seventy-eight percent of the tagged fish moved between the hours of 20:00 and 07:59.
- Type
- Academic
- Authors
- Feola, Jennifer
- Date of Issue
- 2007-08
- Publisher
- Humboldt State University, Natural Resources: Fisheries
- Units
- REDW
- Keywords
- Akaike's Information Criterion, Bayes statistics, binomial expansion, Boyes Creek, change in discharge, change in flow, change in water temperature, Coho Salmon, coho smolts, Competition, DARR, Darroch Analysis with Rank-Reduction, day of year, degree days, Difference, Discharge, downstream migration, environmental variables, Flow, fyke net, Humboldt County, linear stepwise regression, lunar cycle, Movement, Northern California, partial logistic model, PIT tag, PIT tag antenna, Prairie Creek, probability of capture, probability of migration, rating curve, Redwood National and State Parks, size frequency distribution, Streelow Creek, Thesis, trap efficiency, Tukey's Honest Significant, Water Temperature, year