The yield of wild and hatchery trout from Big Spring Creek, Montana
by Norman Walter Peterson
A thesis submitted to the Graduate Faculty in partial fulfillment of the requirements for the degree of
MASTER OF SCIENCE in Fish and Wildlife Management
Montana State University
© Copyright by Norman Walter Peterson (1970)
Abstract:
Estimates on the yield of wild and hatchery trout were made on a portion of Big Spring Creek,
Montana, during the fishing seasons of 1968 and 1969. The stream was divided into two study sections
(A and B) based on habitat quality, trout populations and fishing intensity. Rainbow trout represented
about 80 percent of the wild trout populations within each sampling subsection (A1 and B1) during
both years. An estimated 49 percent in 1968 and 55 percent in 1969 of all fishermen were interviewed.
Total fishermen-hours were estimated by using "fishing intensity curves". The total fishermen-days per
stream mile was 635 for 1968 and 534 for 1969. The total fisher-men-days per acre for the respective
years was 128 and 104. In 1968, 11,986 game-fish (hatchery trout included) were caught during 5,077
fishermen-days for an average of 2.36 game-fish per fishermen-day.
In 1969, 7,774 game-fish were caught during 4,109 fishermen-days for an average of 1.89 game-fish
per fishermen-day. The yield of wild game-fish increased 14.3 percent from 1968 to 1969 while the
catch-rate of wild trout increased from 0.27 per hour to 0.36. The correlation coefficient for the
relationship between late summer wild trout populations and yield was 0.97. Wild rainbow trout were
not caught and kept in proportion to their relative abundance with respect to size and age. Age groups
IIand III contributed propor-tionally more to the yield than did age group I. The effects of a 50 percent
reduction in stocked hatchery trout on yield, fishing pressure, percent returned, and catch-rate are
discussed. S t a t e m e n t o f P e r m i s s i o n t o Copy
In p r e s e n tin g t h i s
th e sis
in p a r ti a l
fu lfillm e n t o f th e re q u ire ­
m e n ts f o r an a d v a n c e d d e g r e e a t M o n tan a S t a t e U n i v e r s i t y , I a g r e e t h a t
t h e L i b r a r y s h a l l make i t
fre e ly
a v a ila b le fo r in sp e c tio n .
a g re e t h a t p e r m is s io n f o r e x t e n s i v e co p y in g o f t h i s
th e sis
a r l y p u r p o s e s may b e g r a n t e d b y my m a j o r p r o f e s s o r , o r ,
absence, by th e D ire c to r of L ib ra r ie s .
co p y in g o r p u b l i c a t i o n o f t h i s
th e sis
It
is
fo r sc h o l­
in h is
u n d e r s to o d t h a t any
fo r f in a n c ia l g ain s h a l l n o t
b e a l l o w e d w i t h o u t my w r i t t e n p e r m i s s i o n .
S ig n a tu re
D a te
I fu rth e r
/ f 7
O
I
THE YIELD OF WILD AND HATCHERY TROUT
FROM BIG SPRING CREEK, MONTANA
by
NORMAN WALTER PETERSON
A - t h e s i s ■s u b m i t t e d t o t h e G r a d u a t e F a c u l t y i n p a r t i a l
f u l f i l l m e n t o f t h e r e q u i r e m e n t s , f o r t h e -degree
of
MASTER OF SCIENCE,
in
F i s h a n d W i l d l i f e M an a g em en t
H ead, M a jo r,D e p a rtm e n t
C h a irm a n , E x am in in g C om m ittee -
G r a d u a t e D ean
MONTANA STATE UNIVERSITY
Bozem an, M o n tan a .
J u n e , , 1970
I
iii
ACKNOWLEDGMENT
T he - a u t h o r w i s h e s t o e x t e n d - h i s a p p r e c i a t i o n t o t h o s e .who
a s s i s t e d him d u r i n g t h e c o u r s e o f t h e s t u d y . .
D r. R i c h a r d 1J . .
G raham d i r e c t e d t h e . s t u d y , a i d e d i n f i e l d w o r k , a n d a s s i s t e d i n
■ p r e p a r a t i o n o f t h e m a n u s c r i p t ; Mr. R i c h a r d J o h n s o n , R i c h a r d B aldesa n d R o n a l d .M a r c o u x o f t h e - M o n t a n a F i s h a n d Game D e p a r t m e n t ^ o f f e r e d
many s u g g e s t i o n s - a n d a i d e d i n t h e f i e l d w o r k ; Mr. E d w a rd F u r n i s h ,
D r.. W i l l i a m G o u l d , N e i l M a r t i n , a n d v a r i o u s p e r s o n n e l , o f t h e
M o n t a n a - F i s h - a n d Game D e p a r t m e n t a i d e d i n t h e f i e l d w o r k ; D r . ■
R i c h a r d E.; L u n d a i d e d w i t h s t a t i s t i c a l
a n a ly sis;
a n d my w i f e
E l a i n e g a v e e n c o u r a g e m e n t and. a s s i s t e d w i t h t h e m a n u s c r i p t .
The
i n v e s t i g a t i o n w a s . f i n a n c e d by t h e M o n tan a C o o p e r a ti v e F i s h e r y U nit,
a n d t h e M o n t a n a F i s h a n d -Game D e p a r t m e n t u n d e r F e d e r a l -Aid t o FishR e s t o r a t i o n P r o j e c t s - F - 5 - R - 1 8 "and F - 5 K R - 1 9 .
P e r s o n a l su p p lem en ts,
w e r e r e c e i v e d t h r o u g h t h e N a t i o n a l S c i e n c e -F o u n d a t i o n t r a i n e e s h i p
program
iv
TABLE OF CONTENTSPage
V I T A .........................
ii
ACKNOWLEDGMENT
..........................
. . . . . .
.....................
LIST OF TABLES .
v
LIST OF FIGURES
ABSTRACT .
.
.
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.
iii
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,
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.......................... .....
vi ■
v ii
INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . .
I
DESCRIPTION OF STUDY AREA
3
METHODS
.
.
RESULTS
DISCUSSION ..
.
.
. . ..
.
. . . . . . . . . . . . . . . . . .
.
.
. .
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,
.
.
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. .
. .
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............................... ....................................................... ,
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6
10 ■
30
LITERATURE CITED . . . . . . . . . . . . . . . . . . . . . . .
32
A P P E N D IX ..........................■............................. ............................................................................
34
V
LIST OF TABLES
T ab le
1.
Page
-
P e r c e n t . o f d a y s , w i t h c l e a r , murky-, a n d muddy w a t e r a t
t h r e e s t a t i o n s bn B i g S p r i n g C r e e k , 1 9 6 8 a n d 1 9 6 9 , a n d
a t .o n e s t a t i o n on t h e E a s t F o r k t r i b u t a r y ,. 1969 .....................
35
2.
T o t a l num ber o f fis h e r m e n - d a y s and a v e ra g e num ber o f
f is h e r m e n p e r day ( i n p a r e n t h e s i s ) f o r e a ch o f f i v e s t r a t a
f o r B i g S p r i n g C r e e k , 1968 a n d 1969 ...................................................
16
3.
P o p u l a t i o n and y i e l d e s t i m a t e s o f . w i l d ra in b o w and-brow n
t r o u t ; i n -two s e c t i o n s o f B ig S p r i n g C r e e k , 1 9 6 8 a n d 1 9 6 9 .
( T o t a l , p o u n d s i n p a r e n t h e s i s .and c o n f i d e n c e , i n t e r v a l s
u n d e r l i n e d ) . . , . . . . .. . .
........................................................ 19
4.
E s t i m a t e d g a m e - f i s h y i e l d .and c a t c h - r a t e f o r B ig S p r i n g
C r e e k , 1 9 6 8 a n d 1969
.................................... ..................................................
21
5.
E stim a te d t o t a l -y ie ld o f g am e-fish f o r each o f f i v e
s t r a t a o n w e e k d a y s a n d w e e k e n d s - h o l i d a y s f o r B ig S p r i n g
C r e e k , 1 9 6 8 a n d 1969
. . .
..........................23
6.
E stim a te d t o t a l . y i e l d o f g am e-fish f o r each o f f iv e
s t r a t a f r o m s e c t i o n A a n d B f o r B ig S p r i n g C r e e k , 1968
a n d 1 9 6 9 ' . ■. , ............................... .......................................................................23
7.
C atch -p e r h o u r i n c l u d i n g a l l g a m e - f is h com p arin g w eekdays
w i t h w i t h w e e k e n d s - h o l i d a y s , 1 9 6 8 a n d 1969
...............................
24
P o p u l a t i o n and y i e l d o f w i l d ra in b o w t r o u t by s i z e
i n t e r v a l s f o r s e c t i o n s A a n d B f o r B ig S p r i n g C r e e k ,
1968 and 1969.
(P ercen t in p a r e n th e s is )
. . . . . . . .
26
8.
vi
LIS T OF-FIGURES ■
F ig u re
Page
1 . - S t u d y a r e a , s'h o w in g l o c a t i o n o f s t u d y s e c t i o n s A a n d B
on B ig S p r i n g C r e e k
.......................... 2
2.
F i s h i n g i n t e n s i t y c u r v e s - f o r t h e w e e k e n d s - h o l i d a y s .of
s t r a t u m o n e , (tw o l a r g e r c u r v e s ) a n d s t r a t u m 5 (tw o
s m a l l e r c u r v e s ) f o r B ig S p r i n g C r e e k
. ........................... .....
11
3.
F is h in g i n t e n s i t y cu rv es f o r th e w e ek en d s-h o lid ay s o f .
s t r a t u m 4 f o r B ig S p r in g C ree k
, . ... . . . . . . , . . 1 2
4.
F is h in g i n t e n s i t y c u r v e s ,f o r th e w eekdays o f s tr a tu m 4.
f o r B ig S p r i n g C r e e k
. . . . . . ... . . . . . . , . .
13
v ii
ABSTRACT
E s t i m a t e s on t h e y i e l d o f w i l d a n d h a t c h e r y t r o u t w e r e made on
a p o r t i o n o f - B ig S p rin g C re e k , M o n tan a, d u r in g th e f i s h i n g s e a s o n s
o f 1968 an d 1969.
T he s t r e a m w as d i v i d e d i n t o tw o s t u d y s e c t i o n s
(A a n d B) b a s e d on h a b i t a t q u a l i t y , t r o u t p o p u l a t i o n s a n d f i s h i n g
in te n sity .
R a in b o w t r o u t r e p r e s e n t e d a b o u t 80 p e r c e n t o f t h e w i l d
t r o u t p o p u l a t i o n s w i t h i n e a c h s a m p l i n g s u b s e c t i o n (A^ a n d B^) d u r i n g
b o th y e a r s .
An e s t i m a t e d 49 p e r c e n t i n .1968 a n d 55 p e r c e n t i n 1969
o f a l l fis h e rm e n .w e re ,in te rv ie w e d ,
T o t a l fis h e r m e n -h o u rs w ere e s t i ­
m ated by u s i n g " f i s h i n g , i n t e n s i t y c u r v e s " .
The t o t a l f i s h e r m e n - d a y s
p e r s t r e a m m i l e w as ,635 f o r 1 9 6 8 a n d 5 3 4 f o r 1 9 6 9 .
The t o t a l . f i s h e r
m e n - d a y s p e r a c r e f o r t h e r e s p e c t i v e y e a r s was 128 a n d 1 0 4 .
I n 1968
1 1 , 9 8 6 g a m e - f i s h ■( h a t c h e r y t r o u t , i n c l u d e d ) w e r e c a u g h t d u r i n g 5 , 0 7 7
fis h e rm e n -d a y s f o r an a v e ra g e o f 2 .3 6 g a m e -fish p e r f is h e r m e n -d a y .
In 1 969, 7 ,7 7 4 g a m e - fis h w e re c a u g h t d u r in g 4 ,109 f is h e r m e n - d a y s
f o r an a v e r a g e o f 1 .8 9 g a m e - f i s h p e r f i s h e r m e n - d a y ,
The y i e l d o f
w i l d ■g a m e - f i s h i n c r e a s e d 1 4 . 3 p e r c e n t f r o m 1968 to. 1969 w h i l e t h e
c a t c h - r a t e o f w i l d t r o u t i n c r e a s e d fro m 0 .2 7 p e r h o u r t o 0 . 3 6 .
The
c o r r e l a t i o n c o e f f i c i e n t f o r t h e r e l a t i o n s h i p b e t w e e n . l a t e summer
w i l d t r o u t p o p u l a t i o n s a n d y i e l d w as 0 . 9 7 .
W ild r a i n b o w t r o u t w e r e
n o t c a u g h t and k e p t . i n p r o p o r t i o n t o . t h e i r r e l a t i v e ab u n d an ce w ith
r e s p e c t to s i z e and ag e .
Age g r o u p s I I a n d I I I c o n t r i b u t e d p r o p e r - ,
t i o n a l l y m o r e . t o t h e y i e l d th a n d i d ag e group I .
The e f f e c t s o f a
50 p e r c e n t r e d u c t i o n i n , s t o c k e d h a t c h e r y t r o u t - o n y i e l d , f i s h i n g
p r e s s u r e , p e r c e n t r e t u r n e d , and' c a t c h - r a t e a r e d i s c u s s e d .
INTRODUCTION
E stim a te s o f t o t a l fis h in g e f f o r t ,
c a t c h - r a t e and t h e g a m e - f i s h •
p o p u l a t i o n w e r e made - f o r t h e . u p p e r 9 m i l e s o f B i g - S p r i n g C r e e k i n
C e n t r a l M o n ta n a d u r i n g t h e f i s h i n g s e a s o n s o f 1968 a n d 1 9 6 9 .
d a ta w ere e v a lu a te d to d e te rm in e th e y i e l d o f w ild t r o u t ,
re la tio n sh ip
o f ^ y ield to
c e rta in
p o p u la tio n s ., and t h e . e f f i c i e n c y
c h a ra c te ris tic s
b a sin s,
th e
of th e w ild fis h
a n d e f f e c t o f. s t o c k i n g r a i n b o w t r o u t . ■
B ig S p r i n g C r e e k ;h a s a h i s t o r y
a n d f i v e f l o o d c o n t r o l dams
The
of flo o d in g d u rin g s p rin g ru n o ff
w hich w i l l a l s o s e r v e as s e t t l i n g
a r e p lan n ed f o r t r i b u t a r i e s
u p s tr e a m from t h e c i t y o f
L e w i s t o w n . ( M a r c o u x , 1 9 6 9 ) , . The y i e l d - m a y a l s o p r o v i d e a b a s i s - f o r
e v a lu a tin g th e f u t u r e e f f e c ts , o f th e s e dam s.
—2 —
L E Wl S T O WN
------O
SECTI ON
East Fork
SECTI ON
LEGEND
STATE
FISH
FISH
P OP UL ATI ON
ESTIMATE
o
C E NS US
__ SECTI ON
—
HATCHERI ES
AREAS
CARD
DE P OS I T OR I E S
DI VI S I ONS
HI GHWAY
MILES
O
F ig u re I .
I
2
S tu d y a r e a , s h o w in g l o c a t i o n o f s t u d y s e c t i o n s A and B
o n B ig S p r i n g C r e e k .
DESCRIPTION OF STUDY AREA
B i g S p r i n g C r e e k a r i s e s . . f r o m - s e v e r a l - s p r i n g s -9 m i l e s s o u t h e a s t
o f L ew isto w n ,
L o c a t e d n e a r t h e s t r e a m ' s o r i g i n a r e tw o M o n t a n a F i s h
a n d Game D e p a r t m e n t t r o u t . h a t c h e r i e s .
N um erous b r i d g e s
(2 .3 p e r
s t r e a m m i l e ) , M o n t a n a S t a t e F i s h a n d Game D e p a r t m e n t a c c e s s a r e a s ,
p r i v a t e ac cess, a r e a s , and a r e a s w here th e s tre a m b o r d e r s
p ro v id e c o n s id e ra b le fish erm e n a c c e s s .
t h e hig h w ay
S ev en ty -tw o p e r c e n t o f th e
p e r m a n e n t hom es on ,,the f l o o d p l a i n a r e l o c a t e d w i t h i n t h e l o w e r 3 . 3
stre a m m ile s o f th e s tu d y a r e a .
T h e s t u d y a r e a w a s ■d i v i d e d - i n t o tw o s t u d y s e c t i o n s .
S tu d y
s e c t i o n A b e g a n a t t h e . h i g h w a y b r i d g e 600 f e e t d o w n s t r e a m f r o m t h e
l o w e r t r o u t h a t c h e r y a n d c o n t i n u e d d o w n s t r e a m 1 ; 9 s t r e a m m i l e s to,
t h e c o n f lu e n c e o f ,th e E a s t F o rk t r i b u t a r y ..(F ig u re I ) .
S e c tio n B:
b e g a n a t t h e m o u th o f t h e E a s t F o r k t r i b u t a r y a n d c o n t i n u e d 6 . 1
stre a m m ile s to th e c i t y
lim its
o f L e w isto w n :
T he u p p e r 3 , 5 6 8 f e e t .
( s u b s e c t i o n A j) o f s e c t i o n A h a d an a v e r a g e w i d t h o f 3 6 .5 f e e t and
an a v e ra g e d i s c h a r g e o f 1 2 6 .6 c f s
(M arcoux, 1 9 6 9 ).
A sam p lin g
s e c t i o n b e g i n n i n g a b o u t 2 m i l e s b e l o w t h e m o u th o f - t h e E a s t F o r k
a n d e x t e n d i n g 5 , 8 4 3 f e e t ■.( s u b s e c t i o n B^) h a d a n a v e r a g e w i d t h o f 4 3 . 4
f e e t an d . an a v e r a g e d i s c h a r g e o f ,1 3 4 ,1 c f s .
An a r e a 3 , 7 0 4 f e e t .,long"'
n e a r t h e l o w e r - e n d o f s e c t i o n B w h e r e t h e s t r e a m c h a n n e l w as a l t e r e d
h a d an a v e r a g e w id th a n d .a v e r a g e d i s c h a r g e o f 3 4 .2 f e e t and 1 4 3 .9 c f s ,
re sp e c tiv e ly .
-
4-
'
T he g r a d i e n t f r o m t h e . u p s t r e a m . b o u n d a r y . o f - s e c t i o n A t o t h e down-s t r e a m b o u n d a r y o f s e c t i o n B w as 2 7 . 5 f e e t p e r s t r e a m m i l e .
T u rb id ity -m easu rem en ts
( i n J a c k s o n , u n i t s ) w e r e m ade i n ..each . s u b ­
s e c t i o n a n d n e a r t h e l o w e r e n d o f s e c t i o n B d u r i n g 1 9 6 8 a n d 1969 an d
on t h e E a s t F o r k t r i b u t a r y n e a r i t s
m o u th i n - 1 9 6 9 on. m o s t d a y s when,
c r e e l c e n s u s w as t a k e n .
D a ta , w e r e d i v i d e d i n t o t h r e e - c a t e g o r i e s b a s e d .
on w a t e r c l a r i t y :
( 0 - 3 p p m ) , m u rk y ( 3 + - 7 p p m ) , a n d ..mtiddy (74—.
c le a r
5 0 0 + p p m ) . ■ S e c t i o n A h a d t h e . g r e a t e s t .num ber - o f - c l e a r w a t e r d a y s a n d
t h e s t a t i o n a t t h e lo w e r e n d . o f s e c t i o n B h a d t h e g r e a t e s t num ber o f
m u rk y a n d / o r muddy d a y s
( A p p e n d i x , T a b l e -.1) .
T he E a s t - F o r k t r i b u t a r y
h a d t h e . h i g h e s t p e r c e n t o f muddy w a t e r d a y s i n 1 9 6 9 .
T u rb id ity in ­
c r e a s e d m o re i n t h e E a s t - F o r k a n d s e c t i o n B thai> i n s e c t i o n A f o l l o w i n g
show ers.
R ain b o w -tro u t
- (Satme g a iv d n e ri) a n d b r o w n , t r o u t (Salmo tv u tta )
w e re the, p r e d o m in a n t w i l d .g a m e -fis h s p e c i e s o c c u r r i n g i n b o th s tr e a m
se c tio n s.
M a r c o u x f o u n d ' t h a t - t h e s e tw o s p e c i e s , r e p r e s e n t e d a b o u t 99
p e r c e n t o f t h e w i l d g a m e - f i s h i n 1967 and 1 9 6 8 •p o p u l a t i o n e s t i m a t e s .
A fe w b r o o k t r o u t
(S a lv e ttLnus. f o n tln a lls ) , m o u n t a i n w h i t e f i s h (Pppso-
■pium w illia m so n i), a n d . a r c t i c g rayling - (ThymallUs a ra tla u s) w e r e
p r e s e n t..-.
The l a t t e r p r o b a b ly r e s u l t e d
r e le a s e i n . 1966.
f r o m an i n a d v e r t e n t h a t c h e r y
O n ly 4 s u c k e r s p e r a c r e , i n c l u d i n g lo n g n o s e s u c k e r
(Catostomus ■oatestem us)■ a n d w h i t e s u c k e r (Catostomus GormersonD3 w e r e
t a k e n i n s u b s e c t i o n A j , b u t 186 w e r e t a k e n i n s u b s e c t i o n B^ a n d .247 i n
-5 -th e a l t e r e d
area
( M a r c o u x , 1 9 .6 9 ).
M arcoux, (1969) fo u n d t h a t t h e f i s h
p o p u l a t i o n - i n - t h e a l t e r e d p o r t i o n of, s e c t i o n B w a s - s i m i l a r t o s u b ­
s e c tio n
T h is a l t e r e d
a r e a w as n o t , s a m p l e d i n 1 9 6 9 .
H a tc h e ry
r a i n b o w t r o u t ^were p l a n t e d i n b o t h s e c t i o n s ' p r i o r t o a n d d u r i n g
th e stu d y ,
METHODS
B e g i n n i n g on o p e n i n g d a y (May 1 9 , 1 9 6 8 a n d May 1 8 , 1 9 6 9 ) o f e a c h
s tu d y y e a r and c o n t i n u i n g t o S ep tem b er 1 5 , 1968 and S ep te m b e r 14,
1 9 6 9 , f i s h e r m e n . w e r e c e n s u s e d a m inim um o f f i v e d a y s p e r w e e k w i t h
th e r e s t r i c t i o n
t h a t . a l l w eekends and h o l i d a y s b e i n c l u d e d .
The
s e l e c t i o n o f t h e t h r e e w e e k d a y s c e n s u s e d w as m ade f r o m a t a b l e o f
ra n d o m n u m b e r s .
I f a h o l i d a y f e l l on a w e e k d a y n o t n o r m a l l y c e n ­
s u s e d , t h a t d a y w as a l s o c h e c k e d m a k i n g a t o t a l o f s i x
f o r t h a t w eek.
F ish in g p re s s u re e s tim a te s
c e n s u s days
f o r n o n -c e n s u s weekdays
w e re o b t a i n e d fro m a v e ra g e d d a t a o f t h e c e n s u s e d w eek d ay s f o r t h a t
w eek.
A sim ila r p a r tia l
s t u d i e d by B e st and B o les
T he d a i l y
c e n s u s ■m e t h o d - w a s • t h e m o s t , a c c u r a t e o f f o u r
(1 9 5 6 ).
d i s t r i b u t i o n o f - f i s h i n g i n t e n s i t y w as d e t e r m i n e d by
c o u n t i n g f i s h e r m e n . a t - 7 , 8 , a n d 11 a . m .
and I ,
4,6,
a n d 8 p .m .
( M o u n t a i n D a y l i g h t . T i m e ) . . A h i g h w a y p a r a l l e l e d t h e s t r e a m a t no
g r e a te r , d i s t a n c e th a n 0 .2 6 m ile and fis h e r m e n w ere r e a d i l y v i s i b l e
f r o m t h e h i g h w a y o n - . a t - l e a s t 90 p e r c e n t o f t h e s t r e a m .
w e re, made a s r a p i d l y
as p o s s i b l e
A l l co u n ts
f r o m a v e h i c l e . ■ O nly, i n d i v i d u a l s
who w e r e a c t u a l l y f i s h i n g o r , w a l k i n g t o t h e . s t r e a m w i t h f i s h i n g r o d
i n hand w ere c o u n te d .
As many f i s h e r m e n a s p r a c t i c a b l e w e r e i n t e r v i e w e d f r o m 7 a . m . t o
d a r k .to o b t a i n . l e n g t h o f t i m e f i s h e d ,
t o t a l num ber i n t h e f i s h i n g p a r t y .
-7 t h e g e n d e r an d r e s i d e n c e o f e a c h . i n d i v i d u a l , and t h e s p e c i e s , n u m b er,
w e ig h t,
and t o t a l - l e n g t h
o f ■f i s h
c a u g h t..
C ensus c a r d s w e re g iv e n t o f is h e r m e n
th e y w o u ld c o n t i n u e f i s h i n g
th e cards
(o r p a r t i e s )
a f t e r t h e i n t e r v i e w was m a d e .
c o r r e s p o n d e d t o n u m b e r s on t h e i n t e r v i e w
form s.
o f c a r d r e t u r n w as - e n c o u r a g e d b y , r e q u e s t i n g o n l y p a r t y
num ber o f t r o u t c a u g h t and num ber r e l e a s e d .
stam ped, c a r d s w e re p r o v i d e d .
th a t in d ic a te d
Num bers on
A h ig h r a t e
f i n is h in g tim e ,
P e n c ils and s e l f - a d d r e s s e d
C ards c o u l d . b e r e t u r n e d i n an y -o n e o f
f i v e boxes c o n v e n ie n tly p la c e d a lo n g th e s tre a m o r r o a d ,( F ig u r e I ) .
D u r i n g t h e s t u d y p e r i o d o f 1968 i t
seem ed t h a t a p r o p o r t i o n a t e l y
h i g h e r p e r c e n t o f i n t e r v i e w s w e r e m ade a r o u n d c e r t a i n
as com pared t o
th e r e s t o f th e stre a m .
corresp o n d ed to tr o u t p la n tin g s i t e s
b i a s e d to w ard h a t c h e r y
re c o v e rie s
fish .
access p o in ts
S ev eral access p o in ts
so t h a t c a tc h d a ta .m a y have been
O t h e r s t u d i e s show t h a t m o s t , h a t c h e r y ,
o c c u r w i t h i n a s h o r t ‘d i s t a n c e o f t h e . p l a n t i n g s i t e s
t h e sum m er m o n t h s
also
d u rin g
( B u t l e r and B o rg e s o n , 1 9 6 5 ; and C o o p e r, 1 9 5 2 ).
E l e c t r o - f i s h i n g d a t a f r o m my s t u d y s h o w e d t h a t t h e m a j o r i t y o f h a t c h e r y
ra in b o w - t r o u t w e re l o c a t e d w i t h i n 1 ,0 0 0 f e e t d o w n stream fro m t h e p l a n t ­
in g s i t e s .
The 1 ,0 0 0 f e e t im m e d ia te ly d o w n stream from p l a n t i n g s i t e s
w ere d e s ig n a te d as a c c e s s a r e a s .
I f a p o o l a n d / o r ru n was p r e s e n t
im m e d ia te ly .above a p l a n t i n g s i t e ,
access a rea.
i t was i n c l u d e d as p a r t o f th e
In 1 9 69, t h e num ber o f f is h e r m e n o b s e rv e d and t h e num ber
c o n t a c t e d i n ■10 a c c e s s , a r e a s w e r e e a c h c o m p a r e d t o c o r r e s p o n d i n g
num bers f o r t h e r e s t o f t h e s t r e a m .
-8 P o p u la tio n e s tim a te s
in s u b se c tio n s
and
o f . w i l d , r a i n b o w a n d b r o w n - t r o u t :w e r e made
(F ig u re I ) •
T h e s e w e r e made d u r i n g t h e l a t e
sum m ers o f 1968 a n d 1969> d u r i n g M a r c h , 1 9 6 8 i n s u b s e c t i o n
d u r i n g M a r c h , 1969 i n s u b s e c t i o n A j .
and
T he 1968 summer e s t i m a t e s
b o t h s u b s e c t i o n s w e re o b t a i n e d fro m M a rc o u x ,( 1 9 6 9 ) .
fo r
E stim a te s o f
w i l d t r o u t w e r e made a t 2 - i n c h s i z e i n t e r v a l s , e x c l u d i n g f i s h
less
t h a n 6 . 0 i n c h e s t o t a l l e n g t h , to , c o m p e n s a t e f o r d i f f e r e n t i a l e f f i ­
c ien c y o f - c a p tu r e .
C o m p u t a t i o n s w e r e .made u s i n g t h e B a i l e y M o d i f i ­
c a tio n o f th e P e te rse n e s tim a to r
C o n fid en ce i n t e r v a l s
(fo rm u la . 3 .7 o f R i c k e r , 1 9 5 8 ).
a t t h e 95 p e r c e n t l e v e l w e r e c o m p u t e d u s i n g
fo rm u la 6 o f th e M ich ig an I n s t i t u t e
fo r F is h e r ie s R esearch
(1 9 6 0 ).
F is h p o p u l a t i o n s w e re sam p led w i t h a v a r i a b l e - v o lta g e , p u ls e d D. C. g e n e r a t o r .
C ap tu red , f i s h w e re a n e s t h e s i z e d , m e a s u r e d , w e ig h e d ,
te m p o r a r ily m a rk e d ;w ith a c a u d a l punch o r - a p a r t i a l
c a u d a l .c lip , and
re le a s e d n e a r .t h e c a p tu re s i t e .
H a t c h e r y r a i n b o w t r o u t p l a n t e d i n t h e s t u d y a r e a . t o t a l e d a b o u t ',
1 0 ,0 0 0 i n 1968 and 5 ,0 0 0 i n 1 9 6 9 .
At th e tim e o f p l a n t i n g j
ra n g e d fro m an a v e r a g e w e ig h t o f 2 .6 p e r pound e a r l y , i n
to one p e r pound l a t e
i n t h e 1969 s e a s o n . . .
th e fis h
t h e 1968 s e a s o n ■
B e tw e e n f i v e a n d s e v e n •
p l a n t i n g s o c c u r r e d e a c h summer f r o m May 1 4 xt o th e . l a s t week, i n J u l y .
On e a c h ^ p l a n t i n g d a y , f i s h w e r e d i s t r i b u t e d . a t a n a v e r a g e o f s e v e n
a c c e ss p o in ts in th e stu d y a r e a . ■ P la n tin g s i t e s
and d a t e s w ere s i m i l a r
b e t w e e n y e a r s b u t t h e n u m b e r i n i n d i v i d u a l p l a n t s w as r e d u c e d b y 50
-9 p e r e e n t . -in 1 969.
F i s h s t o c k e d i n 1968 w e re m arked by re m o v in g t h e
a d ip o s e f i n . ■ In 1969, c o lo re d dyes o f v a r io u s
je c te d in tra c u ta n e o u sly in to
th e l e f t
c o m b in a tio n s w ere i n ­
an d /o r rig h t m a n d ib le s.
u s e d w e r e ch ro m iu m o x i d e a n d N a t i o n a l F a s t B l u e 8GXM.
r e p o r t e d t h a t t h e s e dyes w ere e x t e r n a l l y v i s i b l e
K e lly
Dyes
(1967)
i n 100 p e r e n t o f
th e f i s h . f o r a t l e a s t one y e a r a f t e r m ark in g .
An , a d d i t i o n a l 1 , 6 2 5 r a i n b o w t r o u t i n .1968 a n d 1 , 1 5 0 i n 1 9 6 9 w e r e
p la n te d n e a r o r,b e tw e e n th e h a tc h e r ie s .
m arked t o
d e te rm in e i f
T h o s e s t o c k e d i n 1969 w e r e
th e y d r if te d , in to , th e . stu d y a r e a .
RESULTS
F ish in g i n t e n s i t y
h o lid ay s.
d a t a w ere d iv id e d i n t o w eekdays and w eekends-
D a ta w e re f u r t h e r g ro u p e d i n t o
seasonal d is trib u tio n p a tte rn s
one i n c l u d e s
one o f f i v e s t r a t a
and t o f a c i l i t a t e
estim a te s.
t o com pare
S tra tu m
o p e n in g day and t h e f o l l o w i n g t h r e e w e e k s ; s t r a t a
and 4 in c lu d e c o n s e c u tiv e fo u r-w ee k p e r io d s
2, 3,
f o llo w in g s t r a t u m o n e ; and
s t r a t u m 5 c o n t a i n s t h e f i n a l tw o w e e k s .
A n g lin g i n t e n s i t y
d istrib u tio n s
in te n sity
i n h o u r s w a s e s t i m a t e d b y sum m ing t h e d a i l y
o f fis h e r m e n i n . e a c h s t r a t u m and c o n s t r u c t i n g " f i s h i n g
curves"
( e . g . , F ig u re s 2 ,
3, and 4 ).
T o ta l fis h in g p re ssu re
f o r any s t r a t u m th u s becam e t h e t o t a l f i s h e r m e n - h o u r s u n d e r t h a t - , p e r i ­
o d 's
curve.
T o t a l f i s h e r m e n - h o u r s w as c o m p u te d a s t h e sum o f t h e
num ber o f fis h e r m e n u n d e r t h e c u rv e a t e a c h h o u r .
T he l e f t s i d e o f
e a c h c u r v e w as c l o s e d t h r o u g h e x t r a p o l a t i o n f r o m e a r l y m o r n i n g s t a r t i n g
tim e s r e c o r d e d on i n t e r v i e w
form s.
The r i g h t s i d e was c l o s e d b y . e x t r a ­
p o l a t i o n f r o m t h e f i n i s h i n g t i m e s r e c o r d e d on c e n s u s c a r d s u s i n g o n l y
d a t a fro m f i s h e r m e n f i n i s h i n g a f t e r 8 p .m .
A n . e s t i m a t e d 49 p e r c e n t o f a l l f i s h e r m e n w e r e i n t e r v i e w e d i n 1 9 6 8
a n d 55 p e r c e n t i n 1 9 6 9 .
The' r e t u r n o n t h e c e n s u s c a r d s g i v e n t o i n t e r ­
v i e w e d f i s h e r m e n , i n 1 9 6 8 , w as 72 p e r c e n t
1 9 6 9 , w a s - 71 p e r c e n t
(12 p e r c e n t b y m a i l ) .
(2 1 .p e rc e n t by m a il)
T h ere was l i t t l e
and, in
d iffe re n c e
i n th e p e r c e n t r e t u r n b etw e en s t r a t a o r b etw een w eekdays and w eek en d s- .
h o lid a y s.
Observed
19 6 8
Observed
19 6 9
Extrapolated
Ui 1 0 0
5a.m. 6
F ig u re 2.
10
11
12
1p.m. 2
TI ME
OF
3
DAY
F is h i n g i n t e n s i t y c u r v e s f o r th e w e e k e n d s - h o lid a y s o f s t r a t u m one
c u r v e s ) a n d s t r a t u m 5 (tw o s m a l l e r c u r v e s ) f o r B ig S p r i n g C r e e k .
(tw o l a r g e r
-------- O b s e r v e d
1968
--------- O b s e r v e d
19 6 9
--------- E x t r a p o l a t e d
ui 100
r
so
5a.m. 6
1p.m. 2
TI ME
F ig u re 3.
F ish in g i n t e n s i t y
B ig S p r i n g C r e e k .
DAY
cu rv es f o r th e w eek en d s-h o lid ay s of s tra tu m 4 fo r
—13—
_____ O b s e r v e d
19 6 8
--------- O b s e r v e d
1969
--------- E x t r a p o l a t e d
Z 180
1p.m. 2
F ig u re 4.
F ish in g i n t e n s i t y
B ig S p r i n g C r e e k .
T I ME
DAY
c u rv e s f o r th e w eekdays o f s tr a tu m 4 f o r
-1 4 C h a ra c te ristic p a tte rn s
in th e d i s t r i b u ti o n of fis h in g e f f o r t
have been d em o n strated f o r v a rio u s ty p e s o f f i s h e r i e s .
d esc rib ed a s i t u a t io n
Cope (1 9 5 5 )
on Y e llo w s to n e L ake s i m i l a r t o t h e w e e k e n d s -
h o I i days p a t t e r n i n s t r a t u m one
(F ig u re 2) as a " r e s o r t " s i t u a t i o n .
E s c h m e y e r • (19.35) r e p o r t e d a s i m i l a r b i m o d a l d i s t r i b u t i o n
t h a t had a
m o rn in g p e a k fro m 8 t o 10 a .m . an d an e v e n in g p e a k fro m 6 t o
w i t h o v e r 10 p e r c e n t o f a l l
T he d i s t r i b u t i o n s
7 p .m .
f is h in g e f f o r t in th e l a t t e r p e rio d .
o f a n g l i n g . i n t e n s i t y on w e e k e n d s - h o lid a y s f o r
b o t h s t u d y y e a r s on B i g S p r i n g C r e e k w e r e , i n g e n e r a l , b i m o d a l
s t r a t u m o n e ; F ig u r e -2); b u t ,
pea k , a t 4 p . m .
(e .g .,
(e .g .,
a fe w s t r a t a w e r e t r i m o d a l w i t h a n o t h e r ,
1968, F ig u re 3 ).
T he m o r n i n g mode d e c r e a s e d
m o re t h a n t h e . e v e n i n g mode a s t h e s e a s o n p r o g r e s s e d . t h r o u g h A u g u s t
(F ig u re 3 ).
S t r a t u m 5 w a s a p e r i o d o f lo w f i s h i n g i n t e n s i t y . c h a r a c ­
t e r i z e d by a b e l l - s h a p e d d i s t r i b u t i o n .
d u r i n g t h e sum m er p e r i o d o n tw o l a k e s ,
C h u r c h i l l a n d Snow ( 1 9 6 4 ) f o u n d , ,
a b e ll-s h a p e d d is t r i b u ti o n sim i­
l a r to th e w e e k e n d s-h o lid a y s p a t t e r n in stratu m . 5 (F ig u re 2 ) .
(1969)
V in ce n t .
d e s c r i b e d a h e l l - s h a p e d d i s t r i b u t i o n on t h e M a d i s o n R i v e r ,
M o n tan a.
T he d i s t r i b u t i o n
of in te n s ity
on w e e k d a y s , d u r i n g b o t h y e a r s , was
g e n e r a l l y bim o d al f o r e a c h o f th e f i r s t
mode w a s , i n . e a c h
f o u r s t r a t a ; h o w e v e r, t h e 8 p .m .
c a s e , much h i g h e r t h a n t h e 11 a . m . m o d e , ( F i g u r e 4 ) .
T h i s s u g g e s t s t h a t t h e w e e k d a y . i n t e n s i t y w as p r i m a r i l y l o c a l ;
Week­
days . i n s t r a t u m 5 w e re c h a r a c t e r i z e d by a b e l l - s h a p e d d i s t r i b u t i o n and.
-1 5 lo w a n g l i n g i n t e n s i t y .
S i m i l a r d i s t r i b u t i o n p a t t e r n s , w i t h o n l y m inor-
f l u c t u a t i o n s , e x i s t e d f o r t h e sam e s t r a t a b e t w e e n y e a r s
2,
(e .g .,
F ig u re s
3, and 4 ) .
T o t a l f i s h e r m e n - h o u r s w e r e e s t i m a t e d t o b e 1 3 , 1 8 5 i n 1968 com­
p a r e d t o 1 1 ,2 4 4 i n 1969.
h o u r s a t 6 a .m .
T he e s t i m a t e d p e r c e n t o f t o t a l - f i s h e r m e n -
a n d e a r l i e r w as 1 . 3 i n 1 9 6 8 a n d 0 . 5 i n 1 9 6 9 .
The
m a j o r i t y o f . e a r l y m o r n i n g i n t e n s i t y w as on w e e k e n d s - h o l i d a y s .
p e r c e n t o f ; t o t a l f i s h e r m e n - h o u r s a t 9 p .m .
years.
Hunt
The
and l a t e r was 3 .1 f o r b o th
(1966) fo u n d t h a t e a r l y m o rn in g and l a t e e v e n in g f i s h i n g
r e p r e s e n te d o n ly a s m a ll p e r c e n t o f th e o v e r a l l f i s h i n g i n t e n s i t y .
T h e d e c r e a s e i n t o t a l f i s h e r m e n - h o u r s i n 1969 w as d u e t o a d e ­
c r e a s e i n l o c a l f i s h e r m e n : , ( r e s i d i n g i n L ew isto w n an d V i c i n i t y ) .
The
p e r c e n t o f l o c a l f i s h e r m e n - d e c r e a s e d :-from 62 i n 1 9 6 8 t o 52 i n 1 9 6 9 . •
I n 1 9 6 8 , c o n s t r u c t i o n p e r s o n n e l - and- t h e i r . f a m i l i e s ,- t o t a l i n g
a p p ro x i­
m a t e l y - 1 , 1 0 0 p e o p l e , m o v e d - i n t o -L e w i s t o w n a n d r e m a i n e d u n t i l j u s t
b e f o r e t h e - o p e n i n g o f t h e 1969 f i s h i n g , s e a s o n . . T hey -p r o b a b l y c o n ­
tr ib u te d to g re a te r fis h in g in te n s ity
a n d t e n d e d t o c o n c e n t r a t e m o re
i n a c c e s s a r e a s . t h a n o t h e r l o c a l f i s h e r m e n ; . I n 1 9 6 9 , 45 p e r c e n t o f
f i s h e r m e n o b s e r v e d a n d 44 p e r c e n t c o n t a c t e d w e r e i n a c c e s s a r e a s .
T h is i n d i c a t e s
t h a t fish erm e n , w ere c o n t a c t e d i n p r o p o r t i o n t o t h e i r
observed d i s t r i b u t i o n
on t h e s t r e a m .
D u r i n g 1 9 6 8 , the- l e n g t h o f the., a v e r a g e f i s h e r m e n - d a y , a s d e t e r ­
m ined by i n t e r v i e w and c e n s u s . c a r d d a t a ,
on w e e k d a y s w as 2 . 3 6 h o u r s
-1 6 a n d on w e e k e n d s - h o l i d a y s 2 . 9 0 h o u r s .
D u r i n g 1 9 6 9 , i t w as 2 . 6 7 and
2 .8 1 h o u r s , r e s p e c t i v e l y .
T he t o t a l n u m b e r o f f i s h e r m e n - d a y s f o r e a c h s t r a t u m w as d e t e r ­
m ined by d i v i d i n g t h e t o t a l num ber o f f is h e r m e n - h o u r s by t h e a v e ra g e
fish erm e n -d ay f o r t h a t s tra tu m .
days rem ain ed f a i r l y
w as g r e a t e r i n 1 9 6 8
On w e e k d a y s , t h e n u m b e r o f f i s h e r m e n -
c o n s t a n t f o r s t r a t a one th ro u g h 4 (T a b le 2 ) , b u t
( a v e r a g e 6 7 2 ) t h a n i n 1969
(av erag e 5 2 2 ).
In
s t r a t u m 5 , t h e n u m b e r o f f i s h e r m e n - d a y s d r o p p e d 78 a n d 88 p e r c e n t
T a b le 2.
T o t a l num ber o f f is h e r m e n - d a y s and a v e r a g e num ber o f f i s h e r ­
men p e r d a y ( i n p a r e n t h e s i s ) f o r e a c h o f f i v e s t r a t a f o r
B ig S p r i n g C r e e k , 1968 a n d 1 9 6 9 .
1968
S tra tu m
I
2
3
4
'5
T o tal
W eekdays
I/
381 ( 2 7 . 2 )
754 ( 3 9 . 7 )
845 ( 4 2 . 3 )
709 ( 3 5 . 4 )
153 ( 1 7 . 0 )
2 ,8 4 2
1969
W eekendsH o lid ay s
723
461
543
402
106
(9 0 .4 )
(5 1 .2 )
(6 7 .8 )
(5 0 .2 )
(2 1 .2 )
2 ,2 3 5
W eekdays
500 ( 3 5 . 7 )
500 ( 2 6 . 3 )
533 ( 2 6 . 6 )
554 ( 2 7 . 7 )
65 ( 7 . 2 )
2 ,1 5 2
W eekendsH o lid ay s
681
513
351
301
111
(8 5 .1 )
(57.0)
(4 3 .9 )
(3 7 .6 )
(2 2 .2 )
1 ,9 5 7
I / Due t o a d v e r s e w e a t h e r , t h e n o r m a l n u m b e r o f f i s h e r m e n - d a y s p r o b a b l y
was d e c r e a s e d .
f r o m t h e p r e v i o u s s t r a t u m d u r i n g 1968 a n d 1 9 6 9 , r e s p e c t i v e l y .
The
n u m b e r o f f i s h e r m e n - d a y s . on w e e k e n d s - h o l i d a y s sh o w e d a g e n e r a l d e ­
c r e a s e fro m s t r a t u m o n e t h r o u g h 5 f o r b o t h y e a r s .
W e e k e n d s - h o l i d a y s sh o w e d a h i g h e r f i s h i n g i n t e n s i t y p e r day t h a n
w eekdays
(T a b le 2 ) .
D u rin g b o th y e a r s ,
49 p e r c e n t o f t h e t o t a l
ts
-17f l s h e r a e n - h o u r s w as - on w e e k e n d s - h o l i d a y s .
w as o b s e r v e d b y v a r i o u s o t h e r a u t h o r s
C h u r c h i l l a n d Snow, 19 ,6 4 ).
A h i g h e r w eekend i n t e n s i t y
(B ro w n , 1 9 6 9 ; C o p e , 1 9 5 5 ; a n d
T o t a l f i s h e r m e n - d a y s p e r s t r e a m m i l e was
635 f o r 1968 a n d 534 f o r -1 9 6 9 .
V in cen t
( 1 9 6 9 ) f o u n d 490 a n d 590
f i s h e r m e n - d a y s p e r m i l e on t h e M a d i s o n R i v e r
d u r i n g 1966 a n d 1 9 6 7 , r e s p e c t i v e l y ,
( a much w i d e r s t r e a m )
f o r s e a s o n s of co m p arab le l e n g t h .
T o t a l f i s h e r m e n - d a y s p e r a c r e on B ig S p r i n g C r e e k w as 128 f o r 1968 a n d
104 f o r 1 9 6 9 .
M cF adden ( 1 9 6 1 ) f o u n d t h a t f o r t h r e e y e a r s on L a w r e n c e
C reek, a s tre a m c o n s id e re d to have h ig h f i s h i n g i n t e n s i t y
f o r W is­
c o n s i n , t h e a n n u a l f i s h e r m e n - d a y s p e r a c r e r a n g e d b e t w e e n 170 a n d 2 1 8 .
B a s e d o n M o n t a n a F i s h a n d Game D e p a r t m e n t p o s t a l s u r v e y e s t i m a t e s o f
fish in g p re ssu re ,
t h e B ig S p r i n g C r e e k s t u d y a r e a w as c o n s i d e r e d t o
have a h ig h f is h in g i n t e n s i t y
re la tiv e
t o o t h e r s t r e a m s i n M o n tan a.
S e c t i o n A r e p r e s e n t e d 24 p e r c e n t o f th e , s t u d y a r e a , b u t c o n t a i n e d
36 p e r c e n t o f t h e f i s h i n g i n t e n s i t y
i n 19.68 a n d 28 p e r c e n t i n 1 9 6 9 .
The d i s p r o p o r t i o n a t e i n t e n s i t y b e tw e e n s e c t i o n s d e c r e a s e d a s t h e s e a s o n
progressed.
T h i s d i f f e r e n c e i n i n t e n s i t y may h a v e r e s u l t e d
from e a r l y
s e a s o n t u r b i d i t y w h i c h w as g r e a t e r i n s e c t i o n B ( A p p e n d i x , T a b l e I ) .
On d a y s o f h i g h t u r b i d i t y
d u r i n g b o t h y e a r s , o v e r 50 p e r c e n t o f t h e
i n t e n s i t y w as i n s e c t i o n A.
O f f i s h e r m e n i n t e r v i e w e d i n 1 9 6 8 , 69 p e r c e n t w e r e m a l e s , 10 p e r ­
c e n t w e r e f e m a l e s , a n d 21 p e r c e n t u n l i c e n s e d j u v e n i l e s .
p e r c e n ta g e s w ere 72, 9 , and 1 9 , r e s p e c t i v e l y .
In 1969, th e s e
-1 8 I n 1 9 6 8 , t h e num ber o f ra in b o w e x c e e d in g 5 .9 i n c h e s i n . l e n g t h
r e p r e s e n t e d 85 p e r c e n t o f t h e w i l d t r o u t p o p u l a t i o n i n s u b s e c t i o n
a n d 81 p e r c e n t i n s u b s e c t i o n
I n 1969 t h i s s p e c i e s
p e rc e n t o f th e t r o u t in b o th s u b s e c tio n s .
r e p r e s e n t e d 80
The g r e a t e s t n u m b e r a n d
pounds, p e r , a c r e ,o f a l l t r o u t w ere i n s e c t i o n A d u r i n g b o t h s t u d y y e a r s
(T a b le 3 ) .
T h e -siz e d i s t r i b u ti o n
( T a b l e 8 ) show s t h e r e w as a g r e a t e r
p e r c e n t a g e o f l a r g e r ra in b o w t r o u t i n s u b s e c ti o n
A^.
th an in su b se c tio n
T r o u t p o p u l a t i o n d y n a m i c s f o r B ig S p r i n g C r e e k w e r e d e s c r i b e d b y
M arcoux ( 1 9 6 9 ) .
T he o n l y p r e - s e a s o n e s t i m a t e s t h a t c o u l d b e made w e r e '
i n s u b s e c t i o n B^ i n 1 9 6 8 a n d s u b s e c t i o n A^ i n 1 9 6 9 .
C o m p a rin g t h e 1 9 6 8
l a t e summer p o p u l a t i o n s . o f w i l d t r o u t w i t h t h e 1969 s p r i n g p o p u l a t i o n s ■
in d ic a te s
is
an i n c r e a s e i n p o p u l a t i o n s
d u rin g th e w in te r .
a p e rio d o f d e c lin e because o f m o rta lity
N o rm a lly t h i s
and s lo w g r o w t h .
c r e a s e may b e d u e t o i m m i g r a t i o n a n d / o r s a m p l i n g e r r o r .
The i n ­
M cF adden
(1961) fo u n d t h a t c h a n g e s i n num ber an d w e ig h t o f b r o o k t r o u t w i t h i n
a s i n g l e s t r e a m s e c t i o n a r e i n f l u e n c e d c o n s i d e r a b l y b y m ovem ent o f
fish .
D u r i n g b o t h y e a r s , t h e y i e l d w as e s t i m a t e d a s t h e p r o d u c t o f t h e
to ta l fish in g p ressu re
( f i s h e r m e n - h o u r s ) and th e c a t c h - r a t e
(fish p er
h o u r a s t a k e n f r o m i n t e r v i e w i n f o r m a t i o n o n l y ) . . T he y i e l d s w e r e c a l ­
c u l a t e d f o r w e e k d a y s , w ee k e n d s - h o I i d a y s , a n d f o r e a c h s t r a t u m t o
co m p en sate f o r p o s s i b l e d i f f e r e n c e s .
The, t o t a l y i e l d . f o r e a c h s t u d y
y e a r t h e n b e c a m e t h e sum o f t h e s t r a t a y i e l d s .
T he h a r v e s t i n p o u n d s
T a b le 3.
P o p u l a t i o n ■a n d y i e l d e s t i m a t e s o f w i l d r a i n b o w a n d b ro w n t r o u t i n tw o s e c t i o n s
o f B ig S p r i n g C r e e k , 1 9 6 8 a n d 1 9 6 9 .
( T o ta l pounds i n p a r e n t h e s i s and c o n f id e n c e
____________ i n t e r v a l s u n d e r l i n e d ) .
_________ ______________________________________________________ •
S ectio n
A
B
S p rin g P o p u la tio n s
P e r A cre
1968
RAINBOW TROUT■
L a t e Summer P o p u l a t i o n s
P e r A cre .
312 (9 7 )
2 7 6-348
E stim a te d Y ie ld
P e r A cre
198 (8 1 )
1969
460 ( 1 6 4 )
410.-510
282 ( 1 1 8 )
2 3 8-326
1968
232 .(1 4 5 )
189-276
131 ( 6 7 )
103-158
43 (2 2 )
166 ( 1 1 4 )
1 41-191
80 (4 9 )
1969
128
(4 8 )
. BROWN TROUT
A
B
1968
55 (6 5 )
42-67
19 (2 3 )
12
1969
78 (6 4 )
61-94
70 (6 3 )
56-84
1968
35 (3 2 )
24-46
31 (3 0 )
22-40
8 (7)
41 (4 0 )
3 4 -4 8
12 (9 )
1969
(1 0 )
-2 0 w as e s t i m a t e d a s t h e p r o d u c t o f t h e y i e l d s
a v e r a g e w e i g h t .of t h e t r o u t
w ere c a u g h t d u r in g 5 ,0 7 7 fis h e r m e n -d a y s
(T a b le 4 ) .
and th e
caught f o r th e v a rio u s d iv is io n s .
In 1 968, an e s t i m a t e d 1 1 ,9 8 6 g a m e - f is h
p e r fish erm e n -d ay
( t o t a l num bers)
(h a tc h e ry t r o u t ' in c lu d e d )
f o r an a v e ra g e o f . 2 .3 6 f i s h
I n 1 9 6 9 , an e s t i m a t e d 7 ,7 7 4 g a m e - f is h
w ere c a u g h t d u r in g 4 ,1 0 9 f is h e r m e n - d a y s f o r an a v e ra g e 1 .8 9 f i s h p e r
fish erm e n -d ay
(T a b le 4 ) .
W ild an d h a t c h e r y ra in b o w t r o u t c o n t r i b u t e d 9 6 .3 p e r c e n t o f gam efish
t a k e n d u r i n g 1968 a n d 9 3 . 9 i n 1969
(T a b le 4 ) .
The b r o w n ' t r o u t
c a tc h c o n t r i b u t e d m ost to t h e re m a in in g p e r c e n ta g e d u r in g b o th y e a r s ,
w h ile a r c t i c
g r a y l i n g and b ro o k t r o u t w e re r a r e l y
ra in b o w t r o u t , m arked and u n m a rk e d , c o n t r i b u t e d
ta k e n .
H a tc h e ry
7 1 .0 p e r c e n t o f a l l
g a m e - f i s h t a k e n i n 1968 a n d 4 7 . 9 p e r c e n t i n 1 9 6 9 .
From 1 9 6 8 t o 1969
t h e r e w as a b o u t a 1 4 . 3 p e r c e n t i n c r e a s e i n t h e y i e l d o f - w i l d g a m e - f i s h
and a 5 6 .3 p e r c e n t d e c r e a s e i n th e y i e l d o f a l l h a tc h e r y f i s h .
The y i e l d s
o f w i l d ra in b o w and brow n t r o u t i n 1 9 6 8 , w e re 1 ,3 8 2
a n d 402 p o u n d s ; a n d i n 1 9 6 9 , 1 , 9 3 7 a n d 360 p o u n d s , r e s p e c t i v e l y .
D u rin g b o th y e a r s
t h e n u m b e r o f r a i n b o w t r o u t was 91 p e r c e n t o f t h e
w i l d t r o u t c a u g h t . i n s e c t i o n A.
trib u te d
I n s e c t i o n B, ra in b o w t r o u t con­
a b o u t 86 p e r c e n t f o r b o t h y e a r s .
T he c o n t r i b u t i o n o f r a i n b o w
t r o u t b y w e i g h t i n s e c t i o n A w as 79 p e r c e n t . i n 1 9 6 8 a n d 83 p e r c e n t i n
1969.
I n s e c t i o n B, i t w as 76 a n d 85 p e r c e n t , r e s p e c t i v e l y .
n ite re la tio n sh ip
A d e fi­
e x i s t e d b e tw e e n t h e y i e l d i n num bers p e r a c r e and .
T ab le 4 .
E s t i m a t e d ■g a m e - f i s h y i e l d a n d c a t c h - r a t e f o r B ig S p r i n g C r e e k , 1968 a n d . 1 9 6 9 .
G a m e-fish
W ild ra in b o w t r o u t
B ro w n . t r o u t
M arked h a t c h e r y ra in b o w t r o u t
( c a u g h t sam e s e a s o n a s p l a n t )
M a rk e d h a t c h e r y r a i n b o w t r o u t ■
(caught seaso n a f t e r p la n t)
I/
U n m ark ed h a t c h e r y r a i n b o w t r o u t —
1968
C atch
P ercen t
N u m b er. o f T o t a l ■ P e r Hour ■
B rook t r o u t
T o tal
C atch
P e r H our
3 ,0 3 3
2 5 .3
0 .2 4
3 ,576
4 6 .0
0 .3 2
407
3 .4
0 .0 3
462
5 .9
0 .0 4
8 ,3 0 5
6 9 .3
3 ,212
41.3,
36
0 .5
—
453
5 ,8
—
22
0 .3
61
14.7
0 .6 5 -/
0 .5 ^ /
—
1 .2
—
M a r k e d h a t c h e r y r a i n b o w t r o u t ■.
p l a n t e d above and " d r i f t i n g "
in to stu d y s e c tio n
A rc tic g ra y lin g
Number
1969
P ercen t
of T o tal
0 .3 3 ^ /
28
0 .2
—
5
0 .1
—
' 5
0 .1
—
8
0 .1
—
1 1 ,9 8 6
0 .9 2
and t o a l e s s e r . d e g r e e ,
7 ,7 7 4
I/
I d e n t i f i c a t i o n b a s e d on e r o d e d f i n s
c o lo ra tio n .
2/
A p p ro x im a te ly 1 0 ,0 0 0 m arked t r o u t w e re s t o c k e d i n t h e s t u d y a r e a i n 1967.
3/
A l l h a t c h e r y com b in ed .
0 .6 9
-2 2 t h e l a t e sum m er p o p u l a t i o n n u m b e r s f o r b o t h r a i n b o w a n d b ro w n t r o u t .
T he s i m p l e c o r r e l a t i o n
th e I p e rc e n t l e v e l .
c o e f f i c i e n t w as 0 . 9 7 w h i c h w as s i g n i f i c a n t a t
F e w e r b ro w n t r o u t w e r e c a u g h t i n p r o p o r t i o n t o
t h e i r a b u n d a n ce i n t h e s t r e a m t h a n w e re w i l d ra in b o w t r o u t .
d i f f e r e n c e i n c a t c h a b i l i t y w as n o t s u f f i c i e n t t o g r e a t l y
c o rre la tio n
T h is
r e d u c e . ,the
c o e ffic ie n t.
S t r a t u m 2 a c c o u n t e d f o r 3 1 . 7 p e r c e n t o f th.e t o t a l y i e l d i n 1968
a n d s t r a t u m o n e a n d 2 e a c h a c c o u n t e d f o r 2 8 . 6 p e r c e n t i n .1969
5 ).
(T a b le
T h e l a r g e s t y i e l d on w e e k d a y s w as i n s t r a t u m 2 a n d on w e e k e n d s -
h o lid a y s i n s tr a tu m one d u rin g b o th y e a r s .
H a rv e s t,o n w eekdays
a c c o u n t e d f o r 5 0 . 9 p e r c e n t o f t h e e s t i m a t e d y i e l d d u r i n g 1968 a n d 5 1 . 4
in
1969 ( T a b l e 5 ) .
S e c t i o n B ,p r o v i d e d 6 1 .8 and 7 1 .4 p e r c e n t o f t h e
t o t a l y i e l d , d u r i n g 1968 and 1 9 6 9 , r e s p e c t i v e l y
(T a b le 6 ) .
D u rin g b o th '
y e a r s , m o re g a m e - f i s h w e r e c a u g h t p e r a c r e o f s t r e a m i n . s e c t i o n A , t h a n
i n s e c t i o n B.
T h e r e w as a n i n c r e a s e i n t h e c d t c h - r a t e o f w i l d t r o i i t ,
fr o m 0 . 2 7
p e r h o u r i n 1968 t o 0 . 3 6 i n 1 9 6 9 , w h i c h w a s a c c o m p a n i e d b y a 50 p e r ­
c e n t d e c r e a s e .i n th e c a t c h - r a t e o f a l l h a tc h e ry f i s h
( T a b 16 4 ) .
The
w e i g h t e d a v e r a g e c a t c h - r a t e i n 1 9 6 8 w as h i g h e r t h a n i n 1 9 6 9 ( T a b l e 7 ) .
L ittle
d i f f e r e n c e ■e x i s t e d i n t h e w e i g h t e d a v e r a g e c a t c h - r a t e b e t w e e n
w e ek d ay s. and w e e k e n d s - h o lid a y s .w ith in each y e a r .
D iffe re n c e s d id e x - .
i s t b e tw e e n s t r a t a , h o w e v e r, a n d . t h e h i g h e s t c a t c h - r a t e was g e n e r a l l y
i n s tr a tu m 2.
C a tc h -ra te s
d e te r m in e d fro m i n t e r v i e w
i n f o r m a tio n w ere
T ab le 5 .
E s t i m a t e d t o t a l y i e l d o f g a m e - f i s h f o r e a c h o f ■f i v e s t r a t a - o n w e e k d a y s a n d
w e e k e n d s - h o l i d a y s f o r B ig S p r i n g C r e e k , 1 9 6 8 a n d 1 9 6 9 .
1968
S tra tu m
W eekdays
I
2
3
4
5
T o tal
1969
W e e k e n d s-h o lid a y s
1 ,8 5 8
1 ,6 0 1
1 ,6 9 2
643
94
5,888
892
2 ,2 0 1
1 ,4 8 8
1 ,275
242
6 ,0 9 8
W eekdays
W e ek en d s-h o lid ay s
-864
1 ,0 9 7 '
889
1 ,0 3 2 .
113
3 ,995
1 ,366
1 ,1 3 0
632
365
286
3 ,7 7 9
I
K>
W
I
E s t i m a t e d t o t a l y i e l d o f g a m e - f i s h f o r . e a c h o f f i v e s t r a t a - - f r o m s e c t i o n A a n d BL
f o r B ig S p r i n g C r e e k , 1968 a n d 1 9 6 9 . .
T ab le 6.
1968
S tra tu m
•
I
2
3
4
5
T o tal
T o ta l p e r acre ■
1969
S ectio n A
S ectio n B
S e c tio n A
1 ,2 9 1
1 ,6 8 7
963
527
113
4 ,5 8 1
536
1 ,459
2 ,1 1 5
2 ,2 1 7
1 ,3 9 1
223
7 ,405
238
600
812
. 466
. 304
61
2 ,2 4 3
263
S e c tio n B
1 ,630
1 ,4 1 5 •
1 ,0 5 5
1 ,0 9 3
338
5 ,5 3 1
178
X
T a b le 7.
C a t c h p e r h o u r .i n c l u d i n g a l l .g a m e - f i s h c o m p a r i n g w e e k d a y s w i t h w e e k e n d s - . .
h o l i d a y s , 1 9 6 8 a n d 1969___________ _______________.
________________
S tra tu m
W eekdays
W e ek en d s-h o lid ay s
In te rv ie w
■I
2
3
4
5
W e ig h te d A v erag e
In fo rm atio n
1968
1969
1968
1969
0 .9 9
1 .2 4
0 .7 5
0 .7 6
0 .6 8
0 .6 5
0 .8 2
0 .6 2
0 .7 0
0 .6 5 .
0 .8 9
1 .2 0
1 .0 7
0 .5 5
0 ,3 1 .
0 .7 1
0 .7 9
0 .6 4
0 .4 3
0 .9 2
0 .9 2
0 .7 0
0 .9 2 ■
0 ,6 9
C ensus C ard I n f o r m a t i o n
I
2
3
4
5
W e ig h te d A v erag e
0 .8 1 .
1 .0 0
0 ,8 4
0 .7 1
0 .7 7
0 .6 2
0 .6 4
0 ,6 7
0 .6 3
0 ,6 0
0 .8 1 .
1 .1 9
1 .0 5 •
0 .5 4
0 .6 4
0 .4 9
0 .7 3
0 ,6 7
0 .6 5
0 .4 2
0 .8 4
0 .6 4
0.86
0 .6 3
i
-F-.
I
-2 5 s l i g h t Iy . h ig h e r - t h a n t h o s e from c e n su s c a r d s .
I n 1 9 6 8 , t h e p re d o m in a n t s i z e o f w i l d ra in b o w t r o u t i n t h e c a tc h
w as i n t h e
8 . 0 - 1 1 .9 i n c h ra n g e w hich c o n t a i n e d 6 8 .1 p e r c e n t o f th e
t o t a l c a tc h i n s e c t i o n A and 6 7 .7 p e r c e n t i n s e c t i o n B (T a b le 8 ) .
M arcoux (1969) d e te r m in e d t h a t w i l d ra in b o w t r o u t i n s e c t i o n A a v e r ­
ag ed 7 .4 i n c h e s a t a n n u lu s I I and 1 0 .8 a t I I I i n 1968. • In s e c t i o n B ,
t h e y ■a v e r a g e d 8 . 1 a n d . 1 1 . 7 i n c h e s , r e s p e c t i v e l y ,
g ro w th r a t e s
it
B a s e d on t h e s e
and c o n s i d e r i n g g ro w th t h r o u g h o u t t h e f i s h i n g s e a s o n ,
a p p e a r s t h a t ag e g rq u p I I p r e d o m in a te d i n t h e 1968 c a t c h f o r b o t h
se c tio n s.
I n 1 9 6 9 , t h e p r e d o m i n a n t . . s i z e i n t h e c a t c h w as i n t h e 8 , 0 -
1 1 .9 in c h ra n g e
(7 2 .4 p e r c e n t )
i n a n n u a l g r o w t h r a t e . s ,- i t
i n s e c t i o n A. • A s s u m in g l i t t l e . c h a n g e
a p p e a rs t h a t age group I I p re d o m in a te d in .
t h e 19.69 c a t c h f o r s e c t i o n A.
M a r c o u x a l s o f o u n d - t h a t : t h e 1967 y e a r
c l a s s w a s q u i t e p r e d o m i n a n t i n s e c t i o n A,
g r e a te r p e rc e n ta g e o f 8 .0 -1 1 .9 in c h f is h
T h i s may a c c o u n t f o r t h e
i n th e c a tc h in 1969.
In
s e c t i o n B; th e 8 .0 -1 1 .9 in c h ran g e c o n ta in e d 5 1 .8 p e r c e n t and th e
1 2 .0 - 1 3 .9 in c h i n t e r v a l 3 4 .2 p e r c e n t .
Age g r o u p s I I a n d I I I w e r e
a p p a r e n t l y i m p o r t a n t i n t h e 1969 c a t c h i n t h i s s e c t i o n .
o f f is h in th e 6 ,0 -7 .9
in ch s i z e i n t e r v a l
T he c a t c h
(c o n sid e re d m o stly y e a r lin g s )
■ exceeded 6 . 0 p e r c e n t o n l y i n s e c t i o n A, 1 9 6 9 , w h e r e t h e y m ade up 1 6 . 1
p e rc e n t.
The l a t t e r a l s o r e f l e c t t h e s t r o n g 1967 y e a r c l a s s .
A l­
t h o u g h i t w as p e r m i s s i b l e t o k e e p f i s h u n d e r 6 . 0 i n c h e s , o n l y two
w ere o b s e rv e d d u rin g t h i s
stu d y .
No e v a l u a t i o n o f t h e b r o w n , t r o u t
T ab le 8.
P o p u la t io n and y i e l d o f w i l d ra in b o w t r o u t by s i z e i n t e r v a l s f o r s e c t i o n s
.A ,a n d B. f o r B i g S p r i n g ' C r e e k , 1968 a n d 1 9 6 9 . - ( P e r c e n t i n p a r e n t h e s i s ) .
1968
S tre a m
S e c tio n
A
S iz e
In te rv a l
T o tal
I/
Y ield
P o p u la tio n I /
Y ie ld
6 . 0 - 7 .9
8 .0 - 9 .9
1 0 .0 -1 1 .9
1 2 .0 -1 3 .9
1 4 .0 -1 5 .9
1 6 .0 -1 9 .9
20+
1 ,3 5 7
538
509
216
29
8
8
2 ,6 6 5
(5 0 .9 )
(2 0 .2 )
(1 9 .1 )
( 8 .1 )
( l.D
( 0 .3 )
( 0 .3 )
272
511
638
221
32
13
0
1 ,6 8 7
(1 6 .1 )
(3 0 .3 )
(3 7 .8 )
(1 3 .1 )
( 1 ,9 )
( 0.8)
( 0 .0 )
671
754
662
240
69
11
0
2 ,4 0 7
(2 7 .9 )
(3 1 .3 )
(27,5)
(10,0)
( 2.8)
( 0 .5 )
( 0.0)
62
386
404
201
26
9
4
1,092
6 . 0 - 7 .9
8 .0 - 9 .9
1 0 .0 -1 1 .9
1 2 .0 -1 3 .9
1 4 .0 -1 5 .9
1 6 .0 -1 9 .9
20+
614
1 ,2 2 8
996
809
403
16
0
4 ,066
(1 5 .1 )
(3 0 .2 )
(2 4 .5 )
(1 9 .9 )
( 9 .9 )
( 0.4)
( 0 .0 )
30
390
521
230
160
15
0
1 ,346
( 2.2)
(2 9 .0 )
(3 8 .7 )
(1 7 ,1 )
(1 1 .9 )
( 1 .1 )
( 0 ,0 ) •
485
1 ,3 4 3
1 ,492
1 ,3 1 1
475
57
0
5 ,1 6 3
( 9,4)
(2 6 .0 )
(28,9)
(2 5 .4 )
( 9,2)
( IiD
( 0 ,0 )
42 ■ ( 1 . 7 )
472
(1 9 .0 )
815
(3 2 .8 )
850
(3 4 .2 )
288
(1 1 .6 )
17
( 0 .7 )
0
( 0 .0 )
2 ,4 8 4
T o ta l
B
P o p u la tio n I /
1969
L a t e summer p o p u l a t i o n e s t i m a t e s p r o j e c t e d
fo r th e e n tir e s e c tio n .
( 5.7)
(3 5 .4 ) ■
(3 7 .0 )
(1 8 .3 )
( 2.4)
( 0.8)
( 0.4)
-
27
-
p o p u l a t i o n a n d y i e l d b y s i z e i n t e r v a l s w as made s i n c e n u m b e r s w e r e
sm a ll f o r b o th y e a r s .
An e s t i m a t e d 83 p e r c e n t o f t h e 1 0 , 0 0 0 m a r k e d h a t c h e r y r a i n b o w
t r o u t s t o c k e d i n . t h e s tu d y a r e a i n 1968 w e re c a u g h t by f is h e r m e n w h ile
64 p e r c e n t o f 5 , 0 0 0 s t o c k e d i n 1969 w e r e c a u g h t .
Of t h e m a r k e d h a t c h e r y f i s h
c a u g h t , i n 1 9 6 9 , 74 t o 89 p e r c e n t
w ere ta k e n w i t h i n 2 w eeks a f t e r s t o c k i n g .
fo u n d t h a t i t
B u t le r and B orgeson
(1 9 6 5 )
r e q u i r e d a n a v e r a g e . o f 6 , 5 d a y s t o h a r v e s t 75 p e r c e n t '
o f th e h a tc h e ry
f i s h .in C a lifo rn ia strea m s.
U n licen se d ju v e n ile s
f is h in g w ith o u t t h e i r p aren ts, had a la r g e r
p r o p o r t i o n o f m ark ed h a t c h e r y t r o u t t h a n was fo u n d i n t h e o v e r a l l
c a tc h
(T a b le 4 ) .
79 p e r c e n t ,
I n 1968 and 1 9 6 9 , h a t c h e r y
r e s p e c tiv e ly in t h e i r c a tc h .
f i s h r e p r e s e n t e d 87 a n d
I n 1 9 6 9 , 83 p e r c e n t w e r e
c o n t a c t e d i n a c c e s s a r e a s , w h e re m ark ed h a t c h e r y t r o u t w e re m ost
a v a ila b le .
The c a t c h o f " d r i f t i n g " h a t c h e r y r a i n b o w t r o u t p l a n t e d a b o v e t h e
s t u d y a r e a i n 1 9 6 9 , am ounted t o o n ly 0 . 3 p e r c e n t o f t h e t o t a ) . c a t c h .
Of t h e t o t a l n u m b e r o f f i s h
p e r c e n t w ere r e l e a s e d .
c a u g h t , i n 1 9 6 9 , a p p r o x i m a t e l y 27 '
T he p e r c e n t r e l e a s e d was a b o u t t h e sam e f o r
w e e k d a y s .and w e e k e n d s -h o lid a y s and b e tw e e n s t r a t a ,
ex cep t stratu m 5
w h e r e a b o u t 50 p e r c e n t w e r e r e l e a s e d .
F i s h i n g p a r t y s i z e ra n g e d from one to s e v e n i n 1968 and one to
10 i n 1 9 6 9 .
One w as t h e m o s t p r e d o m i n a n t s i z e d u r i n g b o t h y e a r s
—
28
—
r e p r e s e n t i n g 4 3 .7 a n d . 4 1 .4 p e r c e n t ,
num bers.
U sin g f i n i s h e d i n t e r v i e w
s u c c e s s o f p a r t i e s w as e s t i m a t e d .
r e s p e c tiv e ly , of th e t o t a l p a rty
and c a rd i n f o r m a t i o n ,
The p e r c e n t o f p a r t i e s
th e fish in g
c a t c h i n g a,
l i m i t o f 10 f i s h p e r i n d i v i d u a l w as 3 . 8 i n 1968 a n d 3 . 0 i n 1 9 6 9 .
percent of p a rtie s
t h e tw o y e a r s ,
c a t c h i n g f i v e o r m o r e . f i s h w as 1 7 . 7 a n d 1 2 . 4 f o r
re sp e c tiv e ly .
I f t h e b a g l i m i t h ad b e e n red u ced , to
f i v e and assu m in g t h a t t h e f i s h
o th e r fish erm en ,
by 1 ,9 8 8
" s a v e d " w o u ld n o t. h a v e b e e n c a u g h t by.
t h e t o t a l y i e l d .o f g a m e - f is h w o u ld .h a v e b e e n re d u c e d
(1 6 .6 p e r c e n t )
p ercent of p a rtie s
i n 1968 and .1 ,0 0 2
(1 2 .9 p e r c e n t )
t r o u t c a u g h t, th e c a t c h - r a t e ,
T he
th e t o t a l
and t h e t o t a l h o u rs f i s h e d p e r p a r t y
T he i n f o r m a t i o n f o r t h e s e r e l a t i o n s h i p s w as t a k e n
fro m ran d o m ly s e l e c t e d
sim p le c o r r e l a t i o n
c e n s u s c a r d s co m b in ed f o r b o t h y e a r s .
The
c o e f f i c i e n t b e tw e e n t o t a l h o u r s p e r p a r t y and t h e
n u m b e r o f f i s h e r m e n i n t h e . p a r t y w as .0 .6 5
cent le v e l) .
i n 1969.
c a t c h i n g n o f i s h w as 2 9 . 4 i n 1 9 6 8 a n d 3 7 . 4 i n 1 9 6 9 .
R e l a t i o n s h i p s b e tw e e n num bers i n t h e f i s h i n g p a r t y ,
w e re com p u ted .
T he
T h e •r e g r e s s i o n
( s ig n if ic a n t a t th e I p e r­
c o e f f i c i e n t w as 2 . 9 3
( i . e . , as t h e num ber
i n t h e p a r t y i n c r e a s e d , f r o m . o n e t o tw o , th e h o u rs f i s h e d i n c r e a s e d
from 2 .5 t o 5 . 4 o r 1 : 2 . 2 ) .
T h i s i n d i c a t e d t h a t t h e a v e r a g e ■f i s h i n g
tim e p e r i n d i v i d u a l i n c r e a s e d w ith , an i n c r e a s e i n t h e , p a r t y
T he s i m p l e c o r r e l a t i o n
and t o t a l t r o u t
siz e .
c o e f f i c i e n t b etw een t o t a l h o u r s p e r p a r t y
c a u g h t w as 0 . 4 3
( s ig n if ic a n t a t th e I p e rc e n t le v e l) .
T he r e g r e s s i o n c o e f f i c i e n t w as 0 , 4 4
(i;e .,,
as th e h o u rs f is h e d
'
-2 9 i n c r e a s e d from one t o tw o , t h e t r o u t c a u g h t i n c r e a s e d fro m 1 .7 to 2 .1
or 1 :1 .2 ).
th e r a te
T h is i n d i c a t e d t h a t as th e h o u rs i n , t h e p a r ty
a t w h ich th e y c a u g h t f i s h
in c re a se d
d ecreased .
T he s i m p l e . c o r r e l a t i o n c o e f f i c i e n t b e t w e e n t o t a l h o u r s p e r p a r t y
a n d t h e c a t c h - r a t e w as - 0 . 1 6
( s i g n i f i c a n t a t th e I p e rc e n t l e v e l ) .
The r e g r e s s i o n , c o e f f i c i e n t w as - 0 . 5 9 .
t o t a l h ours p e r p a rty
The p a r t i a l c o r r e l a t i o n b e tw e e n
and a p a r t i c u l a r p a r t y s i z e h a v in g a d j u s t e d f o r
t h e c a t c h - r a t e was n o t s i g n i f i c a n t T h e
l a t t e r c o r r e l a t i o n c o u l d mean
t h a t th e c a t c h - r a t e d id n o t i n f lu e n c e th e le n g th o f tim e p e o p le s ta y e d
e v e n t h o u g h t h e r e w as a s i m p l e . c o r r e l a t i o n b e t w e e n t o t a l h o u r s p e r
p a r ty and c a t c h - r a t e .
B u t , t h e s i m p l e c o r r e l a t i o n w as b a s e d . on f i s h i n g
p a r t y s i z e , w h i c h w as u s u a l l y g r e a t e r t h a n o n e .
to sta y
L arger p a r tie s
ten d ed
lo n g e r and c a tc h f i s h a t a slo w e r r a t e . •
F ro m .th e se t h r e e r e l a t i o n s h i p s
i t w o u ld a p p e a r t h a t t h e l a r g e r
f i s h i n g p a r t i e s w ere n o t as e f f i c i e n t i n . c a t c h i n g
n o n -fis h in g p e rio d s
t o t h e c e n s u s • c a r d s .■
fish
a n d / o r added
DISCUSSION
T h e re w a s . an i n c r e a s e i n .th e c a t c h o f w i l d t r o u t i n 1969■d e s p i t e
a d e c r e a s e o f som e 2 , 0 0 0 ■ f i s h e r m e n - h o u r s
(1 4 .7 p e r c e n t )
fro m t h e p r e ­
v i o u s : s e a s o n . ' T he i n c r e a s e i n y i e l d f o r b o t h w i l d r a i n b o w a n d b ro w n
t r o u t ;w a s i n s e c t i o n B.
A s s u m in g t h a t t h e l a t e sum m er f i s h p o p u - .
I a t i o n s w ere i n d i c a t i v e o f th o s e f o r t h e e n t i r e s e a s o n ,
w ild tr o u t p a r a lle le d
th e y ie ld of
c h a n g e s i n a b u n d a n c e m o re t h a n c h a n g e s i n
fish in g p re ssu re.
A r e d u c t i o n o f 50 p e r c e n t i n t h e n u m b e r o f m a r k e d h a t c h e r y r a i n ­
bow t r o u t s t o c k e d i n 1 9 6 9 c o m p a r e d to. 1 9 6 8 , r e s u l t e d i n . a
r e d u c t i o n i n t h e c a t c h o f m arked h a t c h e r y f i s h .
71 p e r c e n t -
The c a t c h - r a t e de­
c r e a s e d b y a b o u t , t h e e x p e c t e d 50 p e r c e n t ..b u t t h e i n - r s e a s o n r e t u r n o f
m a r k e d h a t c h e r y t r o u t d e c r e a s e d f r o m 83 t o 64 p e r c e n t .
b e tw e e n , t h e r e t u r n
(19 p e r c e n t )
T he d i f f e r e n c e
o f m arked h a t c h e r y f i s h w a s .p r o b a b ly
due to t h e 1 4 .7 p e r c e n t d e c r e a s e i n f i s h i n g - p r e s s u r e v
D u rin g b o t h y e a r s , w i l d ra in b o w t r o u t w e re n o t c a u g h t and k e p t
in p ro p o rtio n to t h e i r , r e l a t i v e
p a rtic u la rly
abundance w ith re s p e c t to s i z e ,
th o s e u n d e r 1 0 .0 i n c h e s ..
It
i s p ro b a b le t h a t a h ig h
p e r c e n t a g e o f t h e f i s h . r e l e a s e d w e re -under 1 0 .0 i n c h e s .
In h e a v ily
f i s h e d L a w r e n c e C r e e k ,. W i s c o n s i n ^ y e a r l i n g b r o o k t r o u t made- up 48 t o
8 9 . p e r c e n t .o f t h e n u m e r i c a l y i e l d , e x p l o i t a t i o n o f a g e g r o u p I I . r e ­
su lte d in a s c a rc ity
o f o l d e r f i s h and t h e s t a b i l i t y
o f th e popu­
l a t i o n w as b e c o m i n g d e p e n d e n t u p o n t h e r e p r o d u c t i o n o f a s i n g l e a g e
-
group
(M cFadden, 1 9 6 1 ).
31
-
I n B ig S p r i n g C r e e k , a g e g r o u p I l w i l d , r a i n - -
bow t r o u t u s u a l l y p r e d o m i n a t e d i n t h e
p e r c e n t o f age group I I I
and o l d e r
c a tc h w h ile th e e s tim a te d
( lo n g e r th a n 1 2 .0 in c h e s ) v a r ie d -
fr o m 1 5 . 8 t o 4 6 . 5 b e t w e e n y e a r s a n d s e c t i o n s .
age group s t r u c t u r e im p a r ts
T he p r e s e n c e o f m u l t i p l e
a d a m p in g e f f e c t u p o n p o p u l a t i o n f l u c t u ­
a t i o n s , i n t h a t r e p r o d u c t i o n i s n o t d e p e n d e n t.u p o n a s i n g l e age group
(R ic k e r,
1954).
M a rc o u x ,(1 9 6 9 )
d isc u sse d th e e f f e c t s
of h a b ita t q u a lity
on t h e
a b u n d a n c e o f t r o u t p o p u l a t i o n s i n B ig S p r i n g C r e e k , p a r t i c u l a r l y
b elo w t h e E a s t F o rk t r i b u t a r y .
S in c e t h e y i e l d fo llo w e d p o p u la tio n
a b u n d a n c e i t may b e u s e d a s a n i n d i r e c t e s t i m a t o r o f c h a n g e s i n t h e
q u a lity
of h a b ita t
f o l l o w i n g w a te r s h e d im p ro v e m e n ts.
LITERATURE CITED
B e s t , E.- A. a n d H. D. B o l e s .
1956.
An e v a l u a t i o n o f c r e e l c e n s u s
m eth o d s.
C a l i f . D e p t., o f F i s h a n d Game.
42(2):
1 09-115.
B row n, B. E.
1969.
An a n a l y s i s o f t h e O k lah o m a s t a t e . l a k e c r e e l
su rv ey to im p ro v e.c r e e l su rv ey d esig n .
P h .D . T h e s i s , O k l a .
S t . U n i v . , 164 p p .
B u t l e r , R, L. a n d D. P . B o r g e s o n .
tro u t.fis h e ry .
C a l i f . D e p t,
1 2 7 , 47 p p .
1965.
C a lifo rn ia , " c a tc h a b le "
o f F i s h a n d Game.
F is h . B u ll.
C h u r c h i l l , W a r r e n a n d H ow ard Snow.
1964.
C h a r a c t e r i s t i c s o f th e
s p o r t f i s h e r y i n som e n o r t h e r n W i s c o n s i n l a k e s .
W ise. Cons.
D e p t . B u l l . 3 2 , 48 p p .
C o o p e r , E. L .
1952.
R e tu rn s fro m p l a n t i n g s o f l e g a l - s i z e d b ro q k i
b ro w n .a n d ra in b o w t r o u t i n P ig e o n R i v e r , O tseg o C o u n ty ,
M ic h ig an .
T r a n s . A m er, F i s h . S o c . 8 2 :
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APPENDIX
T a b l e - -1« ■ P e r e e n t - o f d a y s -w i t h - c l e a r ,- m u rk y * - a n d muddy - w a t e r -at- .- t h r e e s t a t i o n s o n B ig
S p r in g C re e k , 1968 and 1 9 6 9 , and a t one s t a t i o n on t h e E a s t F o rk t r i b u t a r y , .
1969.
STATION
CLEAR
(0-3 p p m ) - 1968.
1969
MURKY
( 3 + - 7 ppm)
1968
1-969 -
MUDDY;
(7 + - 5 0 0 + ppm)
1968
1969
S u b s e c tio n Aj
73%
83%
8%
. 11% •
19%
6%
S u b sectio n
56%
48%
20% .
37%
24%
15%
L ow er e n d o f - s e c t i o n B
45%
26%
31%
46%
24%
28%
E a st F ork T r i b u t a r y
7%
"34%
59%
I
W
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I
MONTANASTATEUNIVERSITYLIBRARIES
3 762 1001
/
83 4
J
*
N378
-
P446
cop.2
Peterson, N o rman W.
The y i e l d of wi l d and
h a t c h e r y trout f r o m B ig
S p r i n g Creek, M o n t a n a
NAm C
AKlO A D D R E S S
c0 ^ 3 . X