Environmental variables influencing downstream migration of juvenile coho salmon (Oncorhynchus kisutch) in three Northern California streams
Graduation Date
2007
Document Type
Thesis
Program
Other
Program
Thesis (M.S.)--Humboldt State University, Natural Resources: Fisheries, 2007
Committee Chair Name
Walter G. Duffy
Committee Chair Affiliation
HSU Faculty or Staff
Keywords
Linear stepwise regression, Fyke net, Probability of migration, Movement, Change in water temperature, Humboldt State University -- Theses -- Natural Resources, Coho smolts, Size frequency distribution, Discharge, Competition, Partial logistic model, Rating curve, Probability of capture, Flow, Bayes statistics, Environmental variables, Water temperature, Day of year, Change in flow, DARR, Trap efficiency, Akaike's Information Criterion, Downstream migration, Year, Degree days, PIT tags, Northern California, Coho salmon, Lunar cycle, Tukey's Honest Significant Difference, PIT tag antenna, Change in discharge, Binomial expansion, Darroch Analysis with Rank-Reduction
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.
Recommended Citation
Feola, Jennifer E., "Environmental variables influencing downstream migration of juvenile coho salmon (Oncorhynchus kisutch) in three Northern California streams" (2007). Cal Poly Humboldt theses and projects. 1158.
https://digitalcommons.humboldt.edu/etd/1158
https://scholarworks.calstate.edu/concern/theses/k3569684z