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Field Evaluation of Four Strains of Rainbow Trout

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Field Evaluation of Four Strains of Rainbow Trout Field evaluation of four strains of rainbow trout (Salmo gairdneri) by Mary Ellen Mueller A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Fish and Wildlife Management Montana State University © Copyright by Mary Ellen Mueller (1985) Abstract: The performance of four strains of rainbow trout, (Salmo gairdneri) was evaluated under field conditions. Data on field performance of specific strains is needed in order to best utilize a particular fish in a natural environment. Growth, catchability and longevity data were collected in the field by a summer-long creel survey. Fish from each strain were stocked at equal densities in two ponds near Three Forks, Montana, for a replicated field evaluation. The Winthrop domestic strain grew faster and was harvested at a higher rate than were the Erwin, DeSmet or Arlee strains. The Winthrop strain had the highest catchabdlity followed by Aflee, Erwin and DeSmet. The DeSmet strain and the Winthrop strain appeared to remain in the fishery longer, being found in the highest proportions in a population estimate taken 5 months after termination of the creel survey. FIELD EVALUATION OF FOUR STRAINS OF RAINBOW TROUT (Salmo gairdneri) b y Mary Ellen Mueller A thesis submitted in partial fulfillment of the requirements for the degree o f Master of Science i n Fish and Wildlife Management MONTANA STATE UNIVERSITY Bozeman, Montana August 1985 MAIN LIB. fJsys' ii APPROVAL of a thesis submitted by MARY ELLEN MUELLER This thesis has been read by each member of the thesis committee and has been found to be satisfactory regarding content, English usage, format, citations, bibliographic style, and consistency, and is ready for submission to the College of Graduate Studi^= Approved for the D a t e Hcau , via jul ucyai. umeii u Approved for the College of Graduate Studies D a t e Graduate Dean iii STATEMENT OF PERMISSION OF USE In presenting this thesis in partial fulfillment of the requirements for a master's degree at Montana State University, I agree that the Library shall make it available to borrowers under rules of the Library. Brief quotations from this thesis are allowable without special permission, provided that accurate acknowledgment of source is made. Permission for extensive quotation from or reproduction of this thesis may be granted by my major professor, or in his/her absence, by the Director of Libraries when, in the opinion of either, the proposed use of the material is for scholarly purposes. Any copying or use of the material in this thesis for financial gain shall not be allowed without my written permission. Signature _ -v'1' D a t e iv ACKNOWLEDGEMENTS The author wishes to extend her sincere appreciation to the following, who among others, assisted her throughout the course of this study. Dr. Robert White directed the study and assisted in preparation of the manuscript. Drs. Ray White and Robert Eng who critically reviewed the manuscript. Pat Dwyer - for field assistance and help in reviewing the manuscript. All personnel at the Bozeman Fish Technology Center for field assistance and constructive suggestions, especially Robert G. Piper. Friends and other students offered suggestions and aided with field work, most especially Stacey J . Pederson without whose assistance and friendship this study would not have been possible. The midnight marauders assisted with gill netting. My special thanks to my family, and especially to my mother and step-father whose support both financial and moral saw me through. V TABLE OF CONTENTS P a g e L I S T O F T A B L E S ............................................................ v i L I S T O F F I G U R E S ......................................................... v i i i ABSTRACT .................... .. ......................................... x INTRODUCTION ............................... I DESCRIPTION OF STUDY SITE ............................................... 5 M E T H O D S .........................................................................5 in oo oo oo in S t o c k i n g .......................................... Strain Marking. ......................... Creel Census Sampling .............. .. Temperature and Water Chemistry Analysis ................. 10 Population Estimation ........................................... 10 Statistical Analyses ................. ................ .. „ . .12 RESULTS ......................... 13 C r e e l S u r v e y ......................................................... 13 Condition Factor ................................................... 14 G r o w t h .......................................... -..................... 2 9 T e m p e r a t u r e a n d W a t e r Q u a l i t y ................................29 P o p u l a t i o n E s t i m a t e ............................... 35 D I S C U S S I O N ................................................... .■ . .37 C r e e l S u r v e y ......................................................... 3 7 Temperature and Water Chemistry ............................. 39 P o p u l a t i o n E s t i m a t e ..............................................40 C o n c l u s i o n s a n d M a n a g e m e n t R e c o m m e n d a t i o n s ...............4 4 REFERENCES ................................................................ .45 A P P E N D I X ............................... 49 LIST OF TABLES T a b l e P a g e 1. Recorded catch of each strain of rainbow trout and extrapolated totals from creel census conducted at Pond I, Three Forks, Montana. June 8 to September 12 , 1 9 8 2 .......................................................... 1 6 2. Recorded catch of each strain of rainbow trout and extrapolated totals from creel census conducted at Pond 2, Three Forks, Montana. June 8 to September 12 , 1 9 8 2 .......................................................... 1 7 3. Length frequency distributions of rainbow trout strains from creel survey. Data for Pond I. Con­ ducted at Three Forks Ponds, Montana, 1982. (W=Winthrop, E=Erwin, D=DeSmet, A=Arlee; numbers represent numbers of fish caught of that strain) . 22 4. Length frequency distributions of rainbow trout strains from creel survey. Data for Pond 2. Con­ ducted at Three Forks Ponds, Montana, 1982. (W=Winthrop, E=Erwin, D=DeSmet, A=Arlee; numbers represent numbers of fish caught of that strain) . 24 5. Analysis of length frequency distributions of rain­ bow trout prior to stocking and from summer creel survey data for Three Forks Ponds, Montana ..... 26 6. Observed catch per hour of effort in each strata for Pond I, Three Forks, Montana. June 8 to September 12, 1982 . ........................................ 2 7 7. Observed catch per hour of effort in each strata for Pond 2, Three Forks, Montana. June 8 to S e p t e m b e r 12, 1 9 8 2 ............................................. 27 8. Mean condition factors for DeSmet, Winthrop, Erwin, and Arlee strains of rainbow trout at the beginning of the study and during creel survey, Three Forks P o n d s , M o n t a n a , 1 9 8 2 .................... ........ 28 9. Water chemistry and temperature data for Ponds I and 2. Three Forks, Montana, 1982 ......................... 34 vii LIST OF TABLES (continued) T a b l e P a g e 10. Percent by strain of catch from summer creel survey and January gill netting in Pond I, Three Forks, Montana, 1982-1983 ............................................. 3 6 11. Percent by strain of catch from summer creel survey and January gill netting in Pond 2, Three Forks, Montana, 1982-1983 36 viii LIST OF FIGURES Figure Page 1. Location of study site ............................................. 6 2. L o c a t i o n o f T h r e e Fo r k s p o n d s ................................ 7 3. Location and symbols used to distinguish strains. 9 4. Locations of sampling stations in Ponds I and 2, T h r e e F o r k s , M o n t a n a ....................................... .1 1 5. Percentage of total catch of rainbow trout creeled by strain in Ponds I and 2, Three Forks, Montana, 1982. (D=DeSmet, E=Erwin, W=Winthrop, A=Arlee). .15 6. Length frequency histograms of creel survey data from Ponds I and 2, Three Forks, Montana compared to pre-stocking data for Winthrop rainbow trout. (Numbers in blocks represent stratum in which fish w e r e c a u g h t ) ........................................................ 1 8 7. Length frequency histograms of creel survey data from Ponds I and 2, Three Forks, Montana compared to pre-stocking data for Erwin rainbow trout. (Numbers in blocks represent stratum in which fish were caught). ............. ...................... ............. 19 8. Length frequency histograms of creel survey data from Ponds I and 2, Three Forks, Montana compared to pre-stocking data for Arlee rainbow trout. (Numbers in blocks represent stratum in which fish were caught) ........................................................ 2 0 9. Length frequency histograms of creel survey data from Ponds I and 2, Three Forks, Montana compared to pre-stocking data for DeSmet rainbow trout. (Numbers in blocks represent stratum in which fish were caught) ................. .. .............................. .21 ix LIST OF FIGURES (continued) Figure Page 10. Relationship between time and mean weight of DeSmet rainbow trout in Ponds I and 2, Three Forks, Montana, 1982. Strata 1-8 represent two week intervals start­ ing June 6, 1982. The data points at stratum 14 are the average weights of fish collected by gill nets o n J a n u a r y 5 - 1 4 , 19 8 3 ............................................30 11. Relationship between time and mean weight of Erwin rainbow trout in Ponds I and 2, Three Forks, Montana, 1982. Strata 1-8 represent two week intervals start­ ing June 6, 1982. The data points at stratum 14 is the average weights of fish collected by gill nets o n J a n u a r y 5 - 1 4 , 1 9 8 3 .................................. .. 3 1 12. Relationship between time and mean weight of Winthrop rainbow trout in Ponds I and 2, Three Forks, Montana, 1982.
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