Three methods were used to determine the Pacific mackerel

population. The tag and recovery method estimated the

population at 620 short tons. The other two estimates

were based on regression techniques of partyboat catches

and these results yielded 2,921 tons and 1,385 tons,

respectively. All three estimates were below the 10,000

tons prescribed for a fishery and thus no harvest could

be allowed. (14pp.

Knaggs, Eric H.

Sunada, John S.

English

Aquatic Commons

State of California 
The Resources Agency 
Department of F i s h  and Game 
STATUS OF PACIFIC MACKEREL 
SPAWNING POPULATION, 1975 
E r i c  H .  Knaggs 
and 
John S. Sunada 
THIRD ANNUAL PACIFIC MACKEREL REPORT 
MARINE RESOURCES 
Administrative Report No. 75-5 
July 1975 
11 STATUS OF PACIFIC MACL9REL SPAhTING POPULATION, 19 7 5 -  
3 / E r i c  H. l<nagg&/ and .John S .  Sunada-  
ABSTRACT 
Three  methods were used t o  de te rmine  t h e  P a c i f i c  mackere l  
p o p u l a t i o n .  The t a g  and r e c o v e r y  method e s t i n a t e d  t h e  
p o p u l a t i o n  a t  620 s h o r t  t o n s .  The o t h e r  two e s t i m a t e s  
were  b a s e d  on r e g r e s s i o n  t ec t ln iques  o f  party boa^ c a t c h e s  
and t h e s e  r e s u l t s  y i e l d e d  2 , 9 2 1  t o n s  and 1 , 3 8 5  t o n s ,  
r e s p e c t i v e l y .  A 1 1  t h r e e  e s t i m a t e s  were  below t h e  10,000 
t o n s  p r e s c r i b e d  f o r  a  f i s h e r y  and t h u s  no h a r v e s t  cou ld  
b e  a l lowed .  
Marine Resources ,  A d m i n i s t r a t i v e  Report  No. 75-5, J u l y ,  1975. 
O p e r a t i o n s  Research Branch, 350 Golden Shore ,  Long Beach, 
C a l i f o r n i a  90802. 
Marine Resources  Region,  350 Golden Shore ,  Long Beach, 
C a l i f o r n i a  90802. 
STATUS OF PAC IF IC 15ICKEP.EL S'P.AIbTbTI1.iG ' P O E U i J ~ T I O N  
S W I  AX L' LUTI C EbibK LO AT I 13N S 
Thi s  is t h e  t h i r d  acilual r e p o r t  or  t h e  s t n t i i a  of t h e  spawning 
popula t ion  of P a c i f i c  mac;cerel ss r equ i r ed  by Sect icr .  8388.3 of t h e  
F i s h  and Game Code. 
For t h e  1975 estimc:tes, 172 again  used Czii:crr~.le par tyboat  
ca t ches  i n  our  t a g  a ~ - d  rcrc~very  cnd s 2 g r s s s i o n  r i ~ t 5 0 d s  i n  determining 
spawning biomass. Thougl~ partyboar  ca t ches  are iaflcienced by many 
v a r i a 5 l e s  not  r e l a t e d  t o  t h e  s i z e  of t h ~  "n i i f ic  nacke re l  popula t ion ,  
i t  i s  t h e  only  f i s h e r y  f o r  we have rey.-*L~r!y r eao r t ed  d a t a .  
Using t a g  and recovery m e t h d s ,  t h e  P a c i f i c  ~ a c k e r e l  spawning 
popula t ion  was estirrlattd t o  be 629 s h o r t  tons .  Two o t h e r  e s t i m a t e s  of 
spawning bioinass were made us ing  r e g r e s s i o n  techil-iques of h i s t o r i c  par ty-  
boat ca t ches  of P a c i f i c  ciacliere2 from S z ~ l t a  Ca:.nlina I s l and  and t h e  
norchern Channel I s l a n d s  and previous  bidmass estimates. The party-  
boat c a t c h e s  i n  t h e s e  two a r e a s  -in 1974-75 -r-csult i n  spabming biomass 
e s t ima te s  of l e s s  than  2,921 tons  and 1,385 t o n s  r e s p e c t i v e l y .  
A r e g r e s s i o n  of t h e  par tyboat  ca t cb  of Pac5f i.c mackerel o f f  
c e n t r a l  C a l i f o r n i a  and s p a w n i ~ g  b ionass ,  uscd i n  t h e  1973 and 1974 
e s t i m a t e s ,  can no longer  be uscd. A change i n  1974 i n  t h e  logbooks on 
which t h e  par tyboat  ca t ches  were recorded p rcc lu3es  t h e  use  of t h i s  
es t imate .  
A f i s h e r y  s h a l l  be  al-lowed once t h e  P a c i f i c  mackerel spawning 
popula t ion ,  i n  wa te r s  n o r t h  of Funta Eugenia, Fa ja  C a l i f o r n i a ,  
Mexico, exceeds 10,000 t o n s  as s t a t e d  iil Sec t ion  8388.5 of t h e  F i sh  
and G a ~ e  Code. Because t h e  t h r e e  e s t i r r a t e s  a r e  cons iderably  below 
10,000 t o n s  and f i e l d  o b s e r v a t i g n s  d 3  n c t  i n d i c a t e  any s i g n i f i c a n t  
changes i n  t h e  p o p u l a t i o n ,  we conc lude  t h a t  t h e  spawning biomass 
is below 10,000 t o n s .  Thus, t h e r e  i s  no e x c e s s  by which a h a r v e s t  
under  S e c t i o n  8388.5 of t h e  F i s h  and Game Code cou ld  be  a l lowed .  
A summary of t h e  p o p u l a t i o n  e s t i m a t e s  s i n c e  1973 f o l l o w s  and 
r e f l e c t s  t h e  c o n t i n u e d  low l e v e l  of t h e  spawning biomass:  
E s t i u ~ a t e s  of P a c i f i c  Mackerel  Spawning Biomass 
METHODS 
Tag and Recovery 5 ,480 t o n s  2 ,025 t o n s  620 t o n s  
C o r r e l a t i o n  o f  Pest P o p u l a t i o n  
E s t i m a t e s  w /  P a r t y b o a t  Catches  
S a n t a  C a t a l i n a  I s l a n d  6 ,570 t o n s  8,380 tons  Less  than 2921 t o n s  
Nor thern  Channel I s l a n d s  4,730 t o n s  - - 1 ,385  t o n s  
C e n t r a l  C a l i f o r n i a  6 ,210 t o n s  4 ,675 t o n s  - - 
INTRODUCT LOX 
P a c i f i c  m a c k e r e l ,  Scornber jgponicus , occur  from t h e  Gulf o f  
Alaska s o u t h r ~ a r d  i n t o  t h e  Gulf of C a l i f o r n i a .  The s p e c i e s  was never  
abundant  n o r t h  of Honterey Bay and s i n c e  1960,  commercial c a t c h e s  
have become r a r e  n o r t h  o f  P o i n t  Concept ion.  
The o f f s h o r e  e x t e n t  of P a c i f i c  mackere l  spawning p o p u l a t i o n ,  
a s  deduced from l a r v a e  c a t c h e s ,  is about  150 m i l e s  o f f  s o u t h e r n  
C a l i f o r n i a ,  250 m i l e s  o f f  n o r t h e r n  B a j a  C a l i f o r n i a ,  and 200 m i l e s  
o f f  c e n t r a l  Baj a  C a l i f o r n i a .  
Ocean s p o r t  a n g l e r s  t a k e  thousands  of P a c i f i c  mackere l  each  
y e a r .  They a r e  u s u a l l y  among t h e  ha l f -dozen  s p e c i e s  t a k e n  i n  
g r e a t e s t  numbers i n  C a l i f o r n i a ' s  c o a s t a l  w a t e r s .  P a r t y b o a t  l a n d i n g s  
accounted f o r  102,619 P a c i f i c  mackere l  ( a n  e s t i m a t e d  50 t o n s )  i n  1974. 
POPULiiI'ZOS ESTLILITES 
The Department JI F i s h  d7>d Game IS rec:~~;re< r o  1~ak.e a n  a n n u a l  
estimate of  t h e  spz~+ni r i& p?puL? t ion  o f  ":elf i L a a i  :are1 t o  comply 
w i t h  S e c t i o n  8388.3 of t h e  E:.r.s? and G n x  C3dr (Ii2dLcda 1 ) .  For t h e  
1975 e s t i m a t e s ,  w e  ? g a i n  used  s e v e r a l  - e t h , , : ~  ~ t i l i z i n g  p a r t y b o a t  
c a t c h e s  t o  e s t i m a t e  the spawning p o p u l a t i o n  size of  P a c i f i c  m a c k e r e l  
s t o c k s  n o r t h  of  P u n t a  E u g c a i a ,  3aja  CalLfsrn i ; .  These  c o n s i s t e d  of 
e s t i m a t e s  f r o n  t a g g t n g  and r e c a p ~ u r e ,  ard c o r r e l a t i o n  of p a s t  popu- 
l a t i o n  e s t i m a t e s  w i t n  p a r t y b o a t  c a t c i i e s  of l ' a c i f i c  mackere l  from 
two s e l e c t e d  l o c a t i o n s .  
'i'aggi ng 
One e s t i m a t e  was v a d e  hy  u s i n g  ta: dnd r t c o v c r y  d a t a  (Addenda 2 ) .  
T h i s  methods i n v o l l  c:s tilz re I e a s e  avd r?covctry of t agged  P a c i f i c  
m a c k e r e l  and t h e  u t i l i z a t i o n  of' a g e  c c ~ p a s i : I : n  d a t a  from t h e  p a r t y -  
b o a t  c a t c h  t o  c o n v e r t  tile t o t 7 1  p o p u i ~ t ~ ~ o n  t  spawning p o p u l a t i c n  
e s t i m a t e .  A t o t a l  c.5 522  Pacific m a c k e r e l  was t a g g e d  d u r i n g  1 9 7 4 .  
The c a t c h  d a t a  f o r  Y a c i f i c  m a c k e r e l  w e r e  o b t a i n e d  f rom t h e  
p a r t y b o a t  f l e e t  o p e r a t i n g  i n  C a l i f o r n i  a and ::cxir*an w a t e r s .  Only 
t a g g e d  f i s h  r e c a p t u r e d  by t h e  p a r t y b o a t  f l c e L  were  used t o  e s t i m a t e  
t h e  spawning p o p u l s t i c > n  cf P a c i f i c  m a c k e r e l .  
The e s t i m a t e d  s i z e  o f  tile P a c i f i c  ~ n z c k c r e l  spawning p o p u l a t i o n  
u s i n g  t a g g i n g  d a t a  i s  6 2 0  t o n s .  
E s t i m a t e s  Using R e g r e s s i o n  Techn iques  
Two o t h e r  sets  of d a t a  were  used t o  c a l c u l a t e  a d d i t i o n a l  e s t i -  
m a t e s  of  P a c i f i c  mackere l  spawning b io inass ,  i n d e p e n d e n t  of t h e  t a g g i n g  
method. 
The f i r s t  s e t  of d a t a  c o n s i s t e d  of p a r t y b o a t  l a n d i n g s  of 
P a c i f i c  mackere l  c a p t u r e d  i n  t h e  w a t e r s  around tkLe n o r t h e r n  Channel 
I s l a n d s  (San Miguel ,  S a n t a  Rosa, S a n t a  C r u z ,  and Anacapa I s l a n d ) .  
These d a t a  were  c o r r e l a t e d  w i t h  cor responding  e s t i m a t e s  of spawning 
p o p u l a t i o n  de te rmined  f o r  each  y e a r  p r e v i o u s  t o  1969 and f i t t e d  w i t h  
a  curved t r e n d  l i n e  c a l l e d  a  power c u r v e  (Addenda 3 ) .  Tile spawning 
p o p u l a t i o n  e s t i z ~ a t e  f o r  t h i s  s e t  of d a t a  i s  1 , 3 8 5  t o n s .  
The second s e t  of d a t a  c o n s i s t e d  o f  p a r t y b o a t  l a n d i n g s  o f  
P a c i f i c  mackerel  c a p t u r e d  i n  w a t e r s  around S a n t a  Ca ta l - ina  I s l a n d  
and c o r r e l a t e d  w i t h  p r e v i o u s l y  computed s ~ a w n i n g  p o p u l a t i o n  e s t i -  
ma tes .  T h i s  s t a t i s t i c a l  t r e n d  l i n e  i s  a  l i n e a r  r e g r e s s i o n  (Addenda 
4 ) .  Although 6 ,745  P a c i f i c  maclccrel were c a p t u r e d  i n  w a t e r s  around 
S a n t a  C a t a l i n a  I s l a n d ,  t h i s  t r e n d  l i n e  o r  p r e d i c t i v e  model i s  v a l i d  
only  when t h e  number of f i s h  caught  i s  about  11 ,322 ,  t h e  lowes t  d a t a  
p o i n t  used i n  c a l c u l a t i n g  t h e  r e g r e s s i o n .  I f  11 ,322  f i s h  were  c a u g h t ,  
t h e  p o p u l a t i o n  would b e  e s t i m s t e d  a t  2 ,921  t o n s .  Although t h e  d a t a  
do n o t  a l l ~ w  an  e x a c t  e s t i m a t e ,  we can conc lude  t h a t  t h e  sparqniilg 
biomass is  l e s s  t h a n  2 ,921  t o n s .  
A  p r e v i o u s  r e l a t i o n s h i p  between c e n t i a l  C a l i f o r n i a  p a r t y b o a t  
c a t c h e s  of P a c i f i c  mackerel  and spawning p o p u l a t i o n  e s t i m a t e s  i s  
no l o n g e r  v a l i d .  A change i n  logbooks on which t h e  c a t c h e s  a r e  
r e p o r t e d  i n v a l i d a t e s  t h e  u s e  o i  t h i s  sst o f  d a t a .  
DISCUSSION 
The 1 9 7 5  e s t i m a t e s  of t h e  P a c i f i c  mackere l  spawning biomass 
a r e  ex t remely  low. There  i s  an  o p t i m i s t i c .  n o t e ,  however,  because  t h e  
r a t i o  of t h e  s i z e  of t h e  1974 y e a r  c l a s s  t o  t h e  spawners  t h a t  
produced i t  was 7 .5  i. This lnd:i.sltee ' a re in t ive 'y  s u c c e s s f u l  
spawning i n  1974 ;  i!.nri3rLun:rt-eI-y , the S ? ~ J & ~ ~ I ~ . ; I Z  pr) 3.3 l - i i~ior l  a t  t h a t  
t ime was a t  a very low l e v e i .  
Sec t ions  of C a l i f o r n i a  F ish  and Game Code 
P e r t a i n i n g  t o  P a z i f i c  ?lackere1 
8388. Except as  provided i n  S e c t i o n  3388.5, P a c i f i c  mackerel 
may n o t  be talcen o r  possessed a t  any t i r , e  f o r  any Fxrpose except  
l oads  o r  l o t s  of f i s h  may c o n t a i n  18  percent  o r  l e s s  by weight  of 
P a c i f i c  mackerel taken i n c i d e n t a l l y  t o  o t h e r  f i s h i n g  o p e r a t i o n s .  
Such P a c i f i d  mackerel,  i n c i d e n t a l l y  t aken ,  niay be  used f o r  any purpose.  
(Amended by S t a t s .  1972, Ch. 608.) 
8388.3. It i s  the  i n t e n t  of t he  Legislature t h a t  t h e  P a c i f i c  
mackerel resource  be enhanced. During c h i s  p roces s  a  f i s h e r y  s h a l l  
be allowed once the  P a c i f i c  mackerel s ~ a w n i n g  popu la t ion ,  i n  waters  
n o r t h  of Punta Eugenia, Baja  C a l i f o r n i a ,  :.ler:icc, has  reached 10,009 
tons  a s  de te rx ined  by the  department .  Such d e t e r n i n a t i o n  s h a l l  b e  
made pub l i c  i n  an  annual  r e p o r t  t o  t h e  L e g i s l a t u r e  no l a t e r  thar, 
July 31 of each y e a r .  I t  is  a l s o  t h e  i n t e n t  t h a t  a s  t h e  spawning 
popu la t ion  i n c r e a s e s ,  i n  excess  of 20,000 t o n s ,  t h e  s e a s o n a l  quota 
a l s o  be inc reased  but  a t  such a r a t e  a s  t o  al low t h e  cont inued  
i n c r e a s e  i n  t he  P a c i f i c  mackerel popu la t ion .  This  process  should 
cont inue  wi th  t h e  o b j e c t i v e  of maximizing the s u s t a i n e d  h a r v e s t .  
(Added by S t a t s  . 1972, Ch. 608.) 
8388.5. Sec t ion  8388 s h a l l  remain i n  e f f e c t  u n t i l  t h e  d e p a r t r e n t  
deternilnes t h a t  t he  es t imated  P a c i f i c  mackerel spawning popu la t ion ,  
in wate r s  n o r t h  of Punta Eugenia,  Baja C a l i f o r n i a ,  Mexico, exceeds 
10,000 tons .  When t h e  department makes t h i s  de t e rmina t ion ,  a  season 
h a r v e s t  quota equal  t o  20 percent  of t he  amount of P a c i f i c  mackerel 
i n  excess  of 10,000 tons  spawning popu lc t ion ,  a s  determined by the  
Q e p a r t m n t  , s h a l l  t ie ?e?:-?ic,toi.! 1:r:der ?er .~ r l t : s  i.t;sc;:d by t h e  d e p a r t m e n t .  
When t h e  depar tnerLt  iizr ~r;ni::es r:l:ac t h e  s p z ~ n i n g  p o p u l a t i o n  
exceeds  20,000 to ras ,  t h e  ha:\c.s?r q u o t a  s . , ha l l  b? i r lcrcased t o  30 
p e r c e n t  of t h e  excess  ovkr  20 ,OGG t o n s .  
The depar tment  s l ~ z l ?  keep r e c o r d s  of the cat d l  o f  P 'ac i f ic  mackerel 
and when i t  a p p e a r s  t h z t  .it? se.a;;on q u ~ t a .  w i . 1 1  be r z a c h e d ,  i t  s h a l l  
n o t i f y  al-1 permi t  ho'i.de~-:; cf the d a t e  when such i i r i t  w i l l  be  reached  
and t h e r e f o r e  t h e  s z a s c n  c las r?d ,  and sia!.:i. n c t . l ! l y ,  by c e r t i f i e d  m a i l ,  
e 
. - 
a l l  pe rmi t  h o l d e r s  of s u m  c~o r . u r e . .  jPL(.i?i?i by S t z t i ~ .  1972, Ch.  608.) 
8388.7. St~bjec t :  r o  t h e  pi-c!.;isio;:s o f  S ~ c l t i u n ;  8388 and 8388.5 ,  
P a c i f i c  mackerel  seasc;l i s  Z r s r z  Oc tober  1 rh rou~5 September 30. 
(Added by S t a t s .  lg7.2, C h .  506 . )  
ADDENDA 2 
E s t i m a t e s  o f  P a c i f i c  FIackerel  Spawning 
Biomass Using Tagging (Mark and Recap ture )  Methods 
The t o t a l  b iomass  was c a l c u l a t e d  u s j n g  t h e  e q u a t i o n :  
2 P = Cn ( ~ u ) / C n m  
P = biomass  e s t i m a t e  i n  nucibers o f  f i s h .  
n = number of marked f i s h  r e l e a s e d  i n t o  t h e  ? o p u l a t i o n .  
m = number o f  marked f i s h  r e c a p t u r e d .  
u = number o f  unmarked f i s h  c a p t u r e d .  
The v a l u e s  f o r  t h e  e q u a t i o n  were  c a l c u l a t e d  t o  b e :  
2 9 Cn (mtu) = 3.870902354 X 1 0  
with t h e  biomass e s ~ i m a t e d  i n  n u r h e r s  b e i n g :  
P = 1 ,968 ,923  f i s h  
Convers ion t o  pounds i s  accomplished by rnul t i .p lying t h e  number o f  f i s h  
times t h e  average  weigh t  o f  f i s h  sampled.  
P = 1 , 9 6 8 , 9 2 3  f i s h  X 0.985 pounds 
P = 1 , 9  39,389 pounds 
The e s t i m a t e d  p r o p o r t i o n  of spawning biomass (de te rmined  f rom age 
samples)  t o  t o t a l  b iomass  i s  0.636 ; t h e r e f o r e  : 
x Spawning biomass  = 1 ,939 ,389  X 0.636 
= 1 , 2 3 3 , 4 5 1  pounds 
= 617 t o n s  
(620) 
E s t i m a t e s  o.f P a c i f % c  Yac1:erl~l S ? z ~ , . x i ~ . g  Biomass 
Using Pa:-~ybo:~t Catch D z t s  fro2.1 t5e i ~ i a t e r s  
o f f  t h e  N o ~ t h e r n  Chame l  Is.lmds 
The spawning biom'ass was c e l c u l a t e d  us:'r,g a n o n - l i n e a r  r e g r e s s i o n ,  
least  s q u a r e s  f i t  power curve. D a t a  p o i r ~ t s  w c r e  f i t t e d  t o  the fo rmula :  
where:  y = biornass est ir i2te in tt-lcusands o f  pounds 
* 
X = nunber o f  P a c i f i c  ~ rackere l  caught o f f  t h e  n o r t h e r n  
Channel Isl m d s  
b = cocf f i c . i en t  
The c o e f f i c i e n t s  a and E %ere c a i c u i a t e d  by u s i n g  the fol lor . r ing 
e q u a t i o n s  : 
(LnOG x.LOG y.) - (2  LOG s. )  (E LOG y.)  
b = -- e i c I i\ I --.--. -.- C K  
Q (LOG x.)' - (2 LOG x r 2 
e 1 e i' 
A c o r r e l a t i o n  c o e f f i . c i e n t  was a l s o  c.alcul .ated u s i n g  the f o r m u l a :  
n'Z: (LOG x. LOG y.) - (2 LOG x.) (2 LOG y.) 
e i c 1 e I 
----- 
e 1 
r =* 
e i 
The values  of t h e  c o e f f i c i e n t s  and the c o r r e l a t i o n  c o e f f i c i e n t  
are c a l c u l a t e d  t o  be :  
a = .008309748 
b = 2.647169714 
r = .7863828270 
w i t h  t h e  biomass e s t ima te  f o r  1975 be ing :  
b y = ax 
= .008309748 (122) 2.647169714 
= 2,770,361 pounds 
= 1,385 tons  
Est i~ laLer i  of F n c i Z i c  Mackerel S;c,-~-ni.;zg Biomass 
Using P a r t y b o a t  C a ~ c h  frca i-he Wat.er; o f f  Sai' i ta C a t a l i n a  I s l a n d  
The spawning b i o r ~ a s s  was c a l c u l a t e d  as ing a l e a s t  s q u a r e  estimate 
A A n A 
of A and B f i t t e d  t o  t h e  l i n e  y = A + Bx 
where  
y = biomass e s t i m a t e  i n  t h o u s a n l s  o f  pormds. 
x = number of  P a c i f i c  m a c k e r e l  caught  o f f  Santa C a t a l i n a  I s l a n d .  
A 
B = c o e f f i c i e n t  
n n 
The c o e f f i c i e n t s  A and 2 were  c a l c u l a t e d  by usj.ng the f o l l o w i n g  e q u a t i o n s :  
A c o r r e l a t i o n  c o e f f i c i e n t  w a s  z lso c a L c ~ , a t e . 3  u s i n g  t h e  f o r m u l ~ :  
The v a l u e s  of t h e  coeff i .c i .ents  s ad  the. cs r re .1~ t i o n  coe.ff i c i . e n t  a r e  
c a l c u l a t e d  t o  be: 
This fo rmula  i s  n o t  v a l i d  f o r  a s y o r t f i s t i  c a t c h  of l e s s ;  t h a n  11 ,322  
f i s h  (a  p r e d i c t e d  spawning b i o n a s s  of 2,921. t o n s )  , because  t h i s  i s  t h e  
l o w e s t  d a t a  poi.nt used t o  c a l c u l a t e  t h e  r e g r e s s i o n .  T h e r e f o r e ,  from 
t h e  6 ,7h5  fish ceught t:e cannot z s k e  an estinate f r o n  the p r e d i c t i v e  
nodel ,  e x c q t  t o  coilclude r h a t  the sps7,xiinp bio;:.ass is  less than 
2 , 9 2 1  tons. 


Status of Pacific mackerel spawning population, 1975

http://aquaticcommons.org/61/1/Marine_Resources_Administrative_Report_No%5B1%5D._75-5.pdf

Status of Pacific mackerel spawning population, 1975

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