TAqGIK'? STITDIES TO GETER1IINE
THE OFFSHORE-INSHORE; EXCHAI'JGE
OF GROUNDFISH O F F ORERIN AND WASHINGTON
PROGFEBS REPORT NO.
4
I'YITED STATES ATObIIC E;I.'ERGY COMF'IISSION
C0NTR.ACT NO. ~ ~ ( ~ 5 - 1 ) 1 7 3 1
ATTTIN R. MAGILL AND SARY 5. MILBURN
?I% COF4MISSION OF OR?3rX)N
INTRODUCTION
The d i s p o s a l of r a d i o a c t i v e waste
s c i e n t i s t s and t h e public.
F ~ O ~ U Ci ~s Sa
s e r i o u s problem f a c i n g
One s o l u t i o n proposed i s t o dump t h e s e waste
products a t sea, with t h e area of northern Oregon and southern Washington i n
100 t o 1,000 fathoms a s one a r e a of consideration,
However, one of t h e
problems t o be resolved i s t h e subsequent d i s t r i b u t i o n of f i s h e s present in
t h e a r e a where t h e s e wastes would be dumped,
Do t h e s e f i s h move i n s h o r e t o
become a v a i l a b l e t o f i s h e r i e s and hence u t i l i z e d by man?
The most p r a c t i c a l method p r e s e n t l y a v a i l a b l e t o determine t h e migration
of t h e s e deep water f i s h e s i s by tagfring.
Recoveries of tagged f i s h by t h e
inshore f i ~ h e r i e swould rrovide information on t h e offshore-inshcre novements
of t h e s e f i s h .
This i s t h e f o u r t h i n a s e r i e s of annual progress r e p o r t s on a
cooperative study by t h e Atomic Energy Commission ( AEC ) , Bureau of Commercial
F i s h e r i e s (BCF), a d Oregon Fish commission (oFC) t o determine t h e
o f f shore-inshore movements of Dover s o l e (Mi c r o s t omus pacif icus ) and s a b l e f i s h
(Anoplopoma f i b r i a ) ,
Funds f o r t h i s study a r e made a v a i l a b l e from t h e AEC on
a yearly contractual basis,
This r e p o r t w i l l present a b r i e f summary of t h e
work accomplished s i n c e t h e i n i t i a t i o n of t h e study i n 1961 and a more d e t a i l e d
summary of t h e proEress made during t h e past y e a r ( ~ e t o b e r1, 1964 t o
September 30, 1965).
SUMMARY OF PREVIOUS ACTIVITIES
During t h e p r i o d Prom June 1961 t o May 1964, 3,013 Dover s o l e and 4,647
s a b l e f i s h were tagged and released a t various depths from 50 t o 450 fathoms
i n a 35-mile-long area southwest of t h e Columbia River ( ~ i g u r e1 ) .
The
t a g g i n g was done from t h e BCF v e s s e l John N. Cobb and BCF chartered v e s s e l
F i ; u r e 1.
Area of investigation o f f n o r t h e r n oreeon and
sout he pn Washinpt,on.
Commaqda.
T l e d a t e s , d e ~ t h , :nd numbers c f f i s h t l o 7 e d x . 3 r e l e a s e d a r e
shown i n Tzbles 1 and 2,
The t a p r e d f i s h a r e brcuoht i n a s pclrt of t h e c e t c h o f commercial
t r a w l e r s znd, i n t h e cnse o f s a b l e f i s h , o c c a s i o n a l l y l o n g l i n e r s .
The t a g s
a r e recovered by d a i l y c x i v a s s i ~ gof t h e f i s h p r o c e s s i n g p l a n t s i n t h e
A s t o r i a and Warrenton a r e a s a n d i n t e r v i e w i n g t h e v e s s e l s k i p p e r s and f i s h e r m e n
as t h e y unload,
S i n c e t h e t r a x l v e s s e l s u n l o a d bottomfish a t s e v e r a l p o r t s
a l o n g t h e Orecon c o a s t and t h e p r o j e c t b i o l o g i s t i s s t a t i o n e d a t A s t o r i a , it
i s n e c e s s a r y t o t r a v e l t h e c o e s t a t s ~ p r o x i n a t e l ymonthly i n t e r v a l s t o pick up
t a u s and e a t h e r c z t c h d a t a .
reward of $, 50 t o $.
given, has been
aid
A s an i n c e n t i v e f o r p e r s o n s t o r e t u r n a l l t a g s , a
75 p e r t a g , depending on t h e amount o f r e c o v e r y i n f o r m a t i o n
s i n c e 1962,
Wnenever p o s s i b l e , t h e c c n p l e t e t a g - b e a r i n g
f i s h i s r e c o v e r e d a l o n g w i t h t h e d a t e of r e c o v e r y , l o c a t i o n , ~ r , ddepth o f c a t c h .
' h e n t h e s p e c i n e n i s r e t u r ~ e dt o t h e l z b o r a t o r y , s c a l e s and o t o l i t h s a r e
removed f o r a,ge a n a l y s i s , l e n g t h r e c o r d e d f o r qrowth s t u d i e s , an3 t h e s e x noted,
CUWNT ACTIVITIES
T h i s y e a r was s p e n t
ir,
- OCTOBER
1, 1064 TO SEFTEMBER 30, 1965
working ul; t a g r e c o v e r i e s ; org?inizinp, c a t a l o q t n g ,
and ccdin,? t a p - r e t u r n d a t j f o r computer p m q r a m l n g ; c o r r e l a t i n g e f f o r t d a t a
w i t h t a q ret1.rrns; a t ? l y z i n ~age 2nd qrowth d z t a - ; reviewing l i t e r a t u r e ; and
p l a n n i n z a method of a , n a l y s i s t h a t would p r o v i d e t h e most meaninqful r e s u l t s ,
R e t u r n s from s a b l e f i s h ta?,ying have Seen n e g l i q i b l e , t h e r e f o r e , most o f t h e
t i m e :ind e f f o r t has been d i r e c t e d toward Dover s o l e .
The f o l l o w i n g s e c t i o n s ,
u n i e s s o t h e r w i s e s t ~ t e d ,r e f e r o n l y t o Dover s o l e ,
Data P r o c e s s i n g
-
It was d e c i d e d e a r l y i n t h e y e a r t h a t a c o r n ~ a t e rprogram would be t h e b e s t
c;nd e s s i e s t m y t o o r p a n i z e and a n a l y z e t h e s e d a t a ,
T h e r e f o r e it was n e c e s s a r j
Table 1. Numbers of Dover s o l e tagged June 1961
recovery t o September 30, 1965.
Depth
6-6 t o 6-9
NO.
$ Re-
9-11 t o 9-17
No.
%Re-
12-6
No,
% Re-
- May
1964 by depth and t i n e of tagging, and percentage
3-3 t o 3-12
No 4
$ Re-
5-18 t o 6-5
%ReNo,
8-26 t o 9-1
No,
% Re-
11-2 t o 11-3
No.
% Re-
Table
(Cont %nued
----------
--
---
------
--
1963
15'64
-1-23 t o 1-24
8-21 t o 9-6 10-2e t o
1-9 t o 1-24 6 - 1 9 tc? 5-19 Tot21 T c t a l ~ n , ~ o t ~ l
No.
Depth
No.
% IZe% ReNo. . $ R e .
FTo,
$ ReNo.
% Re- Number
Re$ Re(fms) Tagged covered TaRged covered Tagged covered Taqged covered Taaged covered Tagged covered Ta-..,yerlcovered ccverec!
--
11-15
-
(I)
.c
k
a,
.rl
d
$
P
k
0
t o d e c i d e whst d a t a should be p l a c e d cn t h e d c t z ~ r o c e s s i n zc a r d s a d d e v i s e
a s u i t a b l e coding system.
After
consult in.^
t h e OFC s t a t i s t i c i a n , E a r l P u l f o r d ,
it was d e c i d e d t h a t t h e f o l l o w i n g was n e c e s s a r y f o r a complete and t h o r o u g h
analysis:
R e l e a s e Data:
Species
Date of t a g g i n g
Tagging v e s s e l
Location ( g i v e n by l o r a n b e a r i n g )
Type of t a g
Tag number
Lenath of f i s h a t t a y a i n g
Depth of tow ( i n which f i s h was c a p t u r e d )
T o t a l weiqht of f i s h i n tow
Leneth of tow ( t e n t h s o f h o u r s )
Mator s p e c i e s i n c a t c h
Number o f f i s h t a g g e d ard r e l e a s e d ( t h i s tow)
Time of d a y
Recovery Data:
Date
Location (loran bearing)
Depth
Length o f f i s h
Sex
Growth
Age
Time o u t ( d a y s )
D i r e c t i o n of movement
D i s t a n c e rnoved ( n e a r e s t 1 0 m i l e s )
Depth change ( n e a r e s t 25 f a t h o m s )
Recovery v e s s e l
It was a l s o s u g g e s t e d t h a t t h e s e a s o n of t a e q i n g and r e c o v e r y be coded
on t h e card..
The 1961, 1962, 1963, and 1964 t a g r e t u r n s were coded and, except
f o r minor changes, a r e r e a d y f o r punching o n t o d a t a ~ r o c e s s i n gc a r d s .
E f f o r t Data
I n o r d e r t o determine more e x a c t l y t h e m i g r a t i o n a l p a t t e r n of Dover s o l e
and s a b l e f i s h , e f f o r t d a t a s a t h e r e d from t h e l c g bcoks of t h e t r a w l fishermen
a r e beinq summarized on a monthly b a s i s a d w i l l be c o r r e l a t e d w i t h t h e
r e l e a s e and r e c o v e r y d a t a .
These d a t a mzy a l s o be coded and p l a c e d on d a t a
processin? cards f o r ease of handlino,
Freliminary c o r r e l a t i o n of catch
d a t a with t a a recoveries i s discussed i n a l z t e r s e c t i o n of t h i s report.
A R ~and Growth
As was mentioned e a r l i e r , when a specimen i s returned t o t h e laboratory,
s c a l e s and o t o l i t h s a r e renoved f o r age a n a l y s i s and length i s recorded f o r
growth s t u d i e s ,
A review of t h e l i t e r a t u r e concerning Dover s o l e age and
growth shows only two recent works, Hagerman (1952) and Harry (1956).
Review
of t h e s e s t u d i e s and unpublished age and growth d a t a analyzed by Sigurd J,
Westrheim and Alfred R. Morgan shows wide d i f f e r e n c e s i n t h e methodology of
aqing and subsequent r e s u l t s .
Recent t a g r e t u r n s f r m Dover s o l e tagged i n
t h e Willapa Deep i n 1955 (Westrheim and Morgan, 1363) sug3est t h a t previous
methods of aae determination may have been i n a c c u r a t e .
Research i n t o t h i s
problem i s being continued with t h e hope t h a t a b e t t e r technique can be
formulated,
Because of t h e slow growth of t h e Dover s o l e and t h e r e l a t i v e l y s h o r t
time s i n c e t h e f i r s t r e l e a s e s , t h e growth d a t a gathered t o d a t e a r e not
considered i n d i c a t i v e of t h e t r u e yrowth r a t e ,
Many of t h e f i s h recovered
within a year a f t e r r e l e a s e showed a neqative change i n s i z e caused by t h e
shrinkaqe during handling.
A more d e t a i l e d study of growth w i l l be prepared
f o r t h e f i n a l report.
RESULTS
--
Dover Sole
During t h e period from June 1961 t o September 30, 1965, 755 Dover s o l e
t a g s were recovered,
Table 3.
Recoveries of t a g s by y e a r of tagging a r e shown i n
It was noted i n Proqress Report No. 3 t h a t t h e percentages recovered
from each y e a r ' s t o t a l r e l e a s e s were not c o n s i s t e n t .
No explanation was given
Table 3.
Numbers of Dover sole recovered by year of tagging.
Year of
Tagging
Number
Tagged
1964
2,718
TOTAL
9,013
Recoveries by Year
1965 Through
1961 1962 1963 1964 September
9
80
113
% of Tags
Total Recovered
270
165
435
16.0
349
204
755
8.4
a t t h a t time t o explain t h e s e d i f f e r e n c e s , but s e v e r a l 'possible reasons have
s i n c e been o f f e r e d t o explain t h e s e i n c o n s i s t e n c i e s .
Analysis of Tables 1
and 2 i n d i c a t e s t h a t t h e percentage r e t u r n i s s t r o n g l y influenced by t h e
depth a t which t h e f i s h a r e tagged.
Both i n 1962 and 1964, sthe y e a r s from
which t h e highest percentages of t a g s were returned, l a r g e numbers of tagged
f i s h were released i n 100 fathoms o r l e s s .
I n 1964, t h e y e a r from which t h e
highest percentage of t a g s were returned, over 9@ were r e l e a s e d i n 100
fathoms o r l e s s ,
The reverse i s t r u e f o r 1961 and 1963, t h e years from which
t h e lowest percentage of t a g s have been recovered.
Over 7G% o f t h e t a g s
r e l e a s e d during 1962 were r e l e a s e d a t depths over 100 fathoms,
I n 1961, t h e
y e a r of lowest percentage return, over 98% of t h e t a g s were r e l e a s e d i n over
100 fathoms.
Correlation of monthly Dover s o l e landings a t Astoria by depth ( ~ a b l e s4,
5, and 6 ) with t a g r e t u r n s gives a p a r t i a l explanation f o r t h e tagging depth and
percent recovery r e l a t i o n s h i p .
About 8@ of t h e Dover sole landed from t h e
northern half of PMFC Area 2 4 and a l l of Area 2-D f c r t h e period 1961-63 were
caught i n l e s s than 90 fathoms, while 86% of t h e t o t a l recoveries were from 100
fathoms o r l e s s .
I n a d d i t i o n , over 75% of t h e y e a r l y landings from 1961-63
were made from May through September and over 8% of t h e t a g s were recovered
during t h i s same period
a able 7). It i s
apparent, t h e r e f o r e , t h a t those f i s h
tagged and r e l e a s e d in l e s s t h a n 100 fathoms during May o r June of any one y e a r
would be subjected t o an i n t e n s e f i s h e r y .
This p a r t i a l l y explains t h e high
recovery r a t e f o r 1964 when 1,347 r e l e a s e s were made a t 50 fathoms i n May of
t h a t year.
Another f a c t o r which helps t o explain t h e inconsistency in t h e percentages
recovered from each y e a r ' s t o t a l r e l e a s e i s t h e r a t i o of t a g s r e l e a s e d i n
shallow water t o those r e l e a s e d i n deep water,
Since in g e n e r a l a higher
Table 4.
Month & Area
Dover s o l e landings in 1961 a t Astoria f o r PMFC areas 2-C (northern
h a l f ) and 2 4 , showing a r e a , month, and depth of catch,
( Landings i n thousands of pounds, )
0-30
January
2-D
N. Half 2-C
February
2-D
N. Half 2-C
March
2-D
N. Half 2-C
April
2 -D
N. Half 2 4
May
2-D
N. Half 2 4
11
June
2-D
N, Half 2-C
8
July
2-D
N. Half 2 4
31
August
2-D
N. Half 2 4
19
September
2-D
N , Half 2-C
9
October
2-D
N. Half' 2-42
6
November
2-D
N, Half 2-C
-
December
2-D
N. Half 2 4
-
TCTAL
-
-
-
3
-
-
87
30-60
60-90
Depth (Fathoms)
90-120 120-150
150-180
180-230
T o t a l by
Month & Area
Table 5.
Month & Area
Dover s p - r: landings in 1962' a t A s t o r i a f o r FNFC a r e a s 2-C ( n o r t h e r n
h a l f ! an 2-D, showing a r e a , month, and depth of c a t c h ,
( ~ a n d i n ~i ns thousands of pounds, )
0-30
30-60
Depth ( F a t horns
60-90
90-120 1 2 b 1 5 0 150-180
'
180-23b
ToAaL by
& Area
1&;1t11
January
2-D
N. Half 2-C
February
2-D
N. Half 2 4
March
2-D
N, Half 2 4
April
2-D
N. Half 2 4
May
2-D
-
-
-
-
28
N, Half 2 4
-
Tune
2 -D
N. Half 2-C
5
July
2-D
N. Half 2 4
18
-
106
9
-
-
26
172
August
2-D
N. Half 2-C
September
2-D
N, Half 2 4
October
2 -D
N . Half 2 4
November
-
-
1
-
N , Half 2 4
-
December
2-D
N. Half 2-C
-
2 -D
TOTAL
-
105
581
268
134
57
12
32
1,189
Table 6.
Month & Area
Dover s o l e landings i n 1963 a t Astoria f o r PMFC areas 2-C (northern
h a l f ) and 2-D, showing a r e a , month, and depth of catch.
(Landings i n thousands of pounds, )
0-30
30-60
Depth (Fathoms )
60-90
90-120 120-150
T o t a l by
150-180
180-230
Month & Area
January
2-D
N, Half 2-C
February
2-D
N. Half 2-C
March
2-D
N, Half 2-C
April
2-D
N. Half 2-C
1
-
May
2-D
N,' Half 2-C
8
June
2 -D
N. Half 2 4
10
Juls
2-D
N, Half 2 4
15
-
216
2
August
2-D
N, Half 2-C
Ue
-
224
4
223
September
2-D
N, Half 2-C
October
2 -D
N , Half 2-C
-
T
2
-
230
-
-
2
-
November
2 -D
N, Half 2 4
December
2-D
N. Half 2-C
TOTAL
-
-
56
-
-
-
-
-
-
29
-
30
950
458
118
22
9
102
1,715
1
-
-
-
U ' n r l a l n r l
N -'K
1
1
1
1
60'
r l .
rl
ln
rl
15
d
percentaye of t a p s i s recovered from shallow water 2nd lower percentage from
deep water, lumrinq t h e s e t o g e t h e r zives a lcwer over-all percentage recovery
r a t e f o r t h o s e g e a r s i n which most of t h e t a g g i n g was done i n deep water (1961
and 1063).
The opposite r e s u l t i s obtained f o r 1962 and 1964 when most of t h e
t a g g i n p was done i n shallow water.
I n order t o b e t t e r understand t h e inshore-offshore movements of t h e Dover
s o l e , t h e a r e a of t a q e i n g has been separated i n t o two zones a s i l l u s t r a t e d i n
Figure 1.
Area B r e p r e s e n t s t h e shallow r e l e a s e zone,
35 t o 90 fathoms, and
Area A r e p r e s e n t s t h e r e l e a s e zone f r m 90 t o 450 fathoms.
A .grid p a t t e r n
placed a t 10-mile i n t e r v a l s e a s t f r o n 125* West l o n p i t u d e and along each 1 0
microsecond l o r a n bearing l i n e from 2H4 2600 t o 2H4 3600 has been drawn over
t h e e n t i r e a r e a of t a q recovery.
These squares a r e approximately 8 by 10
m i l e s nnd, a . l t k o u ~ l ismall e n o u ~ ht o show some p a t t e r n of mcvernent, t h e y a r e
l e r q e e n o u ~ ht o n u l l i f y a o s t e r r o r s i n t h e reported l o c a t i o n of t a g recovery.
When t h e r e c 0 v e r i . e ~from each y e a r ' s t a ~ g i n ga r e i;ssi,yned t o t h e i r s r e a of
r e t u r n ( F i p r e s 2, 3, 4, and 5 ) , a g e n e r a l n o r t h e s s t and i n s h o r e p a t t e r n of
movement can be seen f o r t h e deep-water r e l e a s e s ( ~ r e aA ) returned during
t h e summer and e a r l y f a l l (May t c November).
Tag r e t u r n s from Area B f o r
t h e same period show e i t h e r some i n s h o r e movement o r no movement.
Although
t h e number of recoveries durinq t h e winter and earljr s p r i n g (b!oveiiber t o ~ a y )
i s much smaller, Area B r e l e a s e s in p e n e r a l show zn opposite southwest movement t o deeper o f f s h o r e a r e a s .
Area A r e c o v e r i e s d u r i n z t h i s period show
l i t t l e o r no movement.
It should be noted i n Table 8 t h a t t h e r e have been v e r j few r e t u r n s i n
any y e a r f o r t h e November t o May period.
One explanation f o r t h i s f a c t i s
t h a t t h e f i s h e r y i s l e s s i n t e n s e durinp t h i s period.
I n a d d i t i o n , Dover s o l e
a r e l e s s a v a i l a b l e because of t h e i r mi2ration i n t o deeper areas.
.gure 2.
Tag recoveries through September 1965, from 1,585 tagged Dover s o l e
released i n Area A during 1961 (no r e l e a s e s i n Area B during 1961).
(Circled nwnbers i n d i c a t e t a g s recovered from November t o May; a l l
o t h e r s were recovered from May t o November, )
Firmre 3,
Tap recoveries through September 1965, from 2,504 tagged Dover s o l e
umbers
released i n Area A and 304 released i n Area B during 1962,
i n upper r i g h t corners of each square a r e t h o s e recoveries from
l r ~ aR: 4rea A recoveries a r e indicated i n lower l e f t corner.
i
- ilur;zbers i n d i c a t e tags recovered from November t o May; a l l
others were recovered f ran May t o November. )
Figure 4.
Tag recoveries through September 1965, from 1,660 tagged Dover s o l e
u umbers
r e l e a s e d i n Area A and 242 r e l e a s e d i n Area B during 1963.
i n upper r i g h t c o r n e r s of each square a r e t h o s e r e c o v e r i e s from
A-q
R: Area A r e c o v e r i e s a r e i n d i c a t e d i n lower l e f t corners.
C i r c l e d numbers i n d i c a t e d t a g s recovered from November t o May;
a l l o t h e r s were recovered from May t o Kovember.)
Figure 5,
Tag recoveries through September 1965, from 947 tagged Dover s o l e
released i n Area A and 1,771 released i n Area B during 1964,
umbers i n upper r i g h t c o m e r s of each square a r e t h o s e -ecoveries
from Area B; Area A recoveries a r e i n d i c a t e d i n lower l e f t corners.
Circled numbers i n d i c a t e t a g s recovered from November t o May; a l l
others were recovered from May t o November, )
Table 8,
Numbers of s a b l e f i s h recovered by y e a r o f ta.gging
and recovery.
b
Recoveries by Year
Year of
Taucing
Number
T a g ~ e d 1961
L961
-
1962
1,413
1963
2,914
1964
320
TOTAL
4,647
1962
1
1963
1964
1965 Through
September
2
9
2
3
1
1
11
3
3
Total
% o f Tags
Recovered
3
0.2
14
0.5
1
0.3
18
0.4
A s was noted e a r l i e r , t h e percentage r e t u r n f o r deep-water r e l e a s e s has
been low
a able
1 ) compared t o t h e percentage r e t u r n f o r shallow r e l e a s e s .
S e v e r a l explanations have been o f f e r e d f o r t h e high r e t u r n r a t e f o r shallow
releases.
The reasons f o r t h e low r e t u r n s from deep-water r e l e a s e s a r e ,
however, not r e a d i l y apparent.
I f t h e Dover s o l e do micrate inshore and
offshore, then t h o s e f i s h tagged i n deep water should become a v a i l a b l e t o
the fishery,
Only a few of t h e s e f i s h have been recovered,
Perhaps t h e
s t r e s s of being brought up from 200 o r 300 fathoms i s too g r e a t .
Westrheim and Morgan (1963 ) recovered
not t h e important consideration.
supports t h i s p o s s i b i l i t y .
of t h e f i s h which t h e y tagged a t
This would suqgest t h a t tkAes t r e s s f a c t o r i s
depths from 180 t o 230 fathoms.
of t h e population was tayged.
However,
One explanation miyht be th-,t only t h e f r i n g e
Unpublished d a t a f r m another t a g ~ i n gs t u d y
It i s hoped t h a t f u r t h e r t a p r e t u r n s and a more
d e t a i l e d ana1ysj.s w i l l t e l l why o u r recovery r a t e from deep water has been so
low.
Sablefish
During t h i s r e p o r t period, only t h r e e s a b l e f i s h have been recovered.
Of
21,
t h e 4,647 tagged over a three-year period (Table 2 ) , only 18 f i s h have been
recaptured and returned t o t h e laboratory.
The recoveries by year of tagging
a r e shown i n Table 8.
The movements of s a b l e f i s h have varied g r e a t l y .
Of t h e 17 r e t u r n s fram
which recovery data a r e known, f i v e have moved more than 25 miles from t h e a r e a
of tagging:
one went 120 miles north i n f o u r months; two went approximately
75 miles south; and two o t h e r s went 275 miles south.
The recovery r a t e of 0.4%
i s s t i l l not adequate t o draw any general conclusions regarding movements,
Sablefish tagging s t u d i e s conducted i n Washington, Oregon, and California
i n 1950 and 1951 produced r e l a t i v e l y low recoveries.
The recovery r a t e s f o r
each s t a t e approximately two years a f t e r i n i t i a t i o n of t h e s t u d i e s were a s
follows:
C a l i f o r n i a 3.2%; Washington 2.9%; and Oregon 1.5% ( ~ o l m b e r gand
Jones, 1954).
A t t h a t time, t h e Oregon f i s h e r y was operating a t a low l e v e l ,
The low number of recoveries can probably be a t t r i b u t e d t o s e v e r a l
f a c t o r s , but t h e major reason appears t o be t h e lack of f i s h i n g e f f o r t in t h e
deeper waters where rnost of t h e marketable s a b l e f i s h a r e found,
have been made from t h e minor Oregon long-line f i s h e r y .
No recoveries
Most of t h e f i s h
recovered have been those caught i n c i d e n t a l l y i n t h e t r a w l catches.
Since
most of t h e l a r g e r s a b l e f i s h a r e found a t depths from 250 t o 450 fathoms, t h e
f i s h a r e l a r q e l y unavailable t o t h e l o c a l t r a w l fishernen,
LITERATURE CITED
Hagerman, F. B. 1952. The biology of t h e Dover s o l e ( ~ i c r o s t o m u s
pacificus) ( ~ o c k i n ~ t o n )C
. a l i f . Dept. of F i s h & Game, Bull. 85.
Harry, G. Y. 1956. Analysis and h i s t o r y of t h e Oregon o t t e r t r a w l
f i s h e r y . Univ. of Wash., Ph.D. t h e s i s .
Holmberg, E. K., and W. G. Jones. 1954. Results of s a b l e f i s h tagging
experiments i n Washington, Oregon, and C a l i f o r n i a . P a c i f i c Marine
F i s h e r i e s Comm., Bull. 3; 103-119.
Westrheim, S. J, , and A. R. Morgan, 1963. R e s u l t s from tagging a spawning
stock of Dover s o l e , Microstomus pacif icus, P a c i f i c Marine F i s h e r i e s
Comrn., Bull. 6; 13-21.