Irish Fisheries Leaflet No 84

Fishery L e a f l e t
Number
84
a n Rolnn
caLmhalochca
agus ~ascalgh
j
i
tI
II
H e r r i n g investigations on t h e
N o r t h W e s t and W e s t c o a s t s
1975-76
J. Molloy and T. D. Kennedy.
1
DEPARTMENT OF AGRICULTURE AND FISHERIES
FISHERIES DIVISION
J Prlollay and T D Kemedx
Abstract
The h e r r i n g f i s h e r i e s o f f t h e northwest and west c o a s t s d u r i n g 1975 and 1976 a r e
reviewed.
D e t a i l s a r e g i v e n about v a l u e of t h e f i s h e r y o f f t h e Donegal, Mayo
and Galbray c o a s t s i n r e c e n t y e a r s .
S c i e n t i f i c examinations show t h a t t h e r e has
been a d e c l i n e i n s t o c k s i z e i n t h e a r e a , c h i e f l y due t o poor r e c r u i t m e n t of young
The que;,tion of management of t h e f i s h e r y i s a l s o d i s c u s s e d i n view of
herring,
t h e i n c r e a s e d c a t c h e s by c o n t i n e n t a l f l e e t s f i s h i n g i n t h e a r e a .
Introduction:
H e r r i n g f i s h i n g t & e s p l a c e throughout t h e y e a r on t h e west and nor-th-r:est
coasts.
During t h e summer months t h e h e r r i n g s landed a r e o f t e n a by-catch i n a mixed f i s h e r y
as t h e b o a t s mainly u s e bottom t r a w l s a t t h i s time.
c a l l e d t h e off-season.
intensive,
For convenience t h i s f i s h i n g i s
During t h e p e r i o d October-February the f i s h i n g i s more
b o a t s f i s h i n g p r i m a r i l y f o r h e r r i n g with midwater t r a w l s , and s o i s
r e f e r r e d t o a s the main season.
The s e c t i o n of t h i s r e p o r t d e a l i n g -7ith t h e north-
west c o a s t i s t h u s d i v i d e d i n t o two p o r t i o n s , one concerned with the p e r i o d March.September 1975 ( t h e off-sixason) and a second concerned w i t h t h e p e r i o d October
1975-February 1976 ( t h e main season).
t h e ::est
1.
k f u r t h e r section d e d s uith the fishery off
coast.
March t o September 1975:
The t o t a l amount of h e r r i n g s l a n d e d a l o n g t h e north-west
,3epternber p e r i o d and t h e l a n d e d v a l u e i s snokm
landed by b o a t s f i s h i n g i n t o Killybegs.
i n Table
c o s s t d u r i n g t h e March t o
1.
These h e r r i n g s irere
Most of them >ie= t a k e n by b o a t s -tihich
m r e u s i n g bottom t r a w l s , and a s such t h e s e h e r r i n g s c c u l d be considered a 'by-catch
i n a mixed f i s h e r y ,
They were caugllt o v e r
wide a r e a e x t e n d i n g from Tory Islrind
o f f t h e n o r t h Donegal c o s s t t o Eagle I s l - ~ n do f f t h e north-west
Playo c o a s t .
'he
l a n d i n g f i g u r e s f a r 1975 ~ i t thh e comparable f i g u r e s f o r p r e c e d i n g y e a r s ; , e r e a s
follows:
'Table 1 :
Tots1 c c t c h a s of h e r r i n g ( ~ r a n s )a n d v&Lue:
For human consumption
Cram
-
1963
Scientific
-
7,610
-6:
Av. P r i c e p e r Cran
Value
E
37,524
4.93
Investi,ptions:
For F i s h a e a i
Crans
-
6:
-
Value
248
-
Herring r e s e a r c h was continued on t h e north-west
c o a s t f r o a Narch t o September 1975, and samples were examined from the c e t c h e s
landed at Killybegs and Burtonport,
A t o t a l of 760 f i s h was extimined f o r
age, l e n g t h , s e x m a t u r i t i e s and v e r t e b r a l counts.
A f u r t h e r 3,400 f i s h were
measured only and t h e l e n g t h s s u b s e c u e n t l y c o v e r t e d t o age u s i n g an age/length
key.
The percentage f a t c o c t e n t of f i l l e t s and t h e number of h e r r i n g s p e r
kilogramme were a l s o e s t i m j t e d and a r e shcrm i n Table 2.
- 4 ygrtebr:ll
The v e r t e b r a l c o u n t , and m , i t u r i t y s t a s s a r e b e t h
Counts and M a t u r i t i e s .
Llsed a s c l i a r a c t e r i s t i c s i n d e f i n i n g a2d i n d e n t i f y i n g r a c e s of h e r r i n g .
The coutits
throug.hout t h e s w e r months s u g g e s t e d t h s t some ? , i n t e r spnrming h e r r i n g s %,ere
present in t h e c a t c h e s .
n o r t h Doncgal
C O ~ C( ~~
T h i s was e s p e c i a l l y n o t i e a b l e i n t h e c a t c h e s t z k e n o f f the
o r yI s l a n d are^), ;;here a m i x t u r e of autumn and w i n t e r sp:irming
f i s h i s n o r m ~ l l yfound only d u r i n g t h e main season.
During March and .;-ipril t h e average f a t c o n t e n t
F3t Content and Hmber p e r k i l o g r a m :
remained low ( 3 ) ~ ) . I n fi; -y, hoi.ever, t h e f a t c o n t e n t was 137; which :;as h i g h e r th,m
~su:~
f ol r t h i s time of t h e y e z r
-
herzing present i n t h e c-tches.
probably because of t h e l a r g e r nunhers of small f a t
As t h e f i s h began t o f e e d and develop i n June t h e
f3t c o n d< n t i n c r e a s e d 2nd reached a maximum of 217; i n l u g u s t ,
The numbers of h e r r i n p s
I
p e r kilogram ranged from 6.1
full m?,turity,
i n . . p r i l t o 4.5 i n ~ u g u s twhen t h e f l s h were a n r o a c h i n g
Immature f i s h i n blsy ; e r e 9.2 p e r kg. and i n September 8,8 p e r kg.
The av, r a g e percentage f a t c o n t e n t and numbers p z r kilogram p e r month s r e s h o - n i n
Fable 2,
i.
October 1975
-
F e p ~ j a r y1976
Landings rind P r i c e s :
he
n s i n season)
The main h e r r i n g f i s h e r y commenced i n O c t s b e r 2975 and
continued i n t o e a r l y February 1976.
&i
landed a t K i l l y b e g s d u r i n g t h i s p e r i o d .
t o t a l of 3 1,887
c r a n s , vsll-led a t 2670,342, rms
This was a d e c r e a s e on 1 s t y e a r ' s f i g u r e which
i t s e l f was c o n s i d e r a b l y lower t h i n i n 1971/74.
The
101;
season was a t t r i b u t e d mainly t o bad weather c o n d i t i o n s ,
'975/76 season.
q u a n t i t y landed i n t h e 1974/75
T h i s cannot be s a i d f o r t h e
The f i s h i n g f l e e t covered a i y i d e a r e a i n t h e i r se,?zch f o r h e r r i n g s
2nd i t .;:as t h e o p i n i o n of e x c e r i e n c e d s k i p p e r s t h ; t i n f ~ ~ tch et r e t,-ere no 1 . r e
c o n c e n t r a t i o n s of h e r r i n g s i n t h e a r e a .
keen demand k e p t p r i c e s h i g h
able
I
Con.-;e?uently 1 5 t h f i s h i n s n ~ r ts u p p l y a
3 ) throughout t h e season.
,1
I
Table 3:
I
I
I
I
Burtonoort
+ i n c l u d e s a d d i t i o n a l l a d i n g s from some s m a l l e r p o r t s .
The t o t a l l a n d i n g s
,
I
a n d v a l u e f a r K i l l y b e g s and W r t o n p o r t f o r t h e l a s t e i g h t seasons a r e
a l s o shown in Table 4.
Table 4:
-
Ge-r.
LA
During t h e s e a s o n t h e nimber of b o a t s engaged i n mid-water t r a w l i n g
v a r i e d from twelve t o f i f t e e n p z i r s
able
5 ) , depending on rthether t h e
Bur tonport f l e e t was 1:-ading i ~ iot K i l l y b e g s .
f i n h i n g i n t o Guliiay a t d i f f e r e n t times.
i n previous y e a r s a r e shorn i n Table 5:
I n a d d i t i o n , s e v e r a l p - . i r s 1,rent
The numbers p ~ r t a k i n gi n the f i s h c r y
I
I
> I
b
e 5:
Gear and v e s s e l ctltepories, 1970/71-!974/75
Trawlers
T:~ble 6:
Cstch and f i s h i n g e f f o r t , 1968/69
,ge a d r e c r u i t m e n t :
-
1975/76
A s s t a t e d i n f i s h e r y l e a f l e t No. 72
t h e main r e c r u i t m e n t t o
t h e a & u l t s t o c k s t a k e s p l a c e when t h e h e r r i n g s a r e three-year o l d ,
Over t h e y e a r s
i t has been shown - h n t t h e amount o f h e r r i n g r e c r u i t i n g t o the a d u l t s t o c ~ s?long
t h e Donegal c o a s t has been h i g n l y v a r i a b l e , and v e r y s t r o n g y e a r c l a s s e s o c c u r only
I
I
a t i n t e r v a l s of 6 o r 7 y e a r s .
The 1963-year c l a s s ( i . e .
h e r r i n g s born i n t h a t y e a r )
was an e x c e p t i o n i l l y s t r o n g one and caused the a d u l t s t o c ~t o i n c r e a s e r a p i d l y i n 1966.
I
This meant t h a t a h i g h c a t c h i n g r a t e was m a i n t a i n e d f o r a few y e a r s subsequent t o
1966 while t h i s y e a r c l a s s was s t i l l abundant.
These h i g h c a t c h e s encoura-ed an
i n c r e a s e i n the f i s h i n g i n t e n s i t y , which was maintained even while t h e 1963-year
Nas no l o n g e r abundant.
I
I
U n f o r t ~ n ~ t e lt yh i s s t r o n g y e a r c l a s s h,.s not s o f a r been
r e p l a c e d by a y e a r c l a s s of comparabie s t r e n g t h and t h e subse:uent
a n d c a t c h i n g r a t e nave t h e r e f o r e d e c l i n e d .
I
2dult stock s l z e
I n ? a b l e 7 t h e age d i s t r i b u t i c n of the
I
I
autumn sparaxem a r e sho~,rn,expzesded a s numbers of f i s h caught p e r age c l a s s p e r
landing,
The =umbers o f t h r - e - y e a r
o l d h e r r i n g s c a n be c l e a r l y s e e n every y e a r .
I
I
For
example t h e averag- number of f i s h i n e-*er,y l a n d i n g i n 1966/67 was 137.0 thousand
I
I
I
I
I
l
and
76,O thousand of t h e s e were t h r e e -
:ar olcls.
However i n
1975/76 t h e L1verso.e
I
number pLir l a n d i n g had d e c r e a s e d t o 74.6 thoilsand o f r:hich o n l y 19.8 tholissrid yere
three-year
olds.
T'ibJ. e
7: Rm,
d i s t r i b u t i o n of autumn spawners, 1963/64
(Thousands of f i s h !%ernigi ~t
' p s ~ r tfrcm t h e e x c e p t i o n e l
-
fl s h i n K )
1563 y e a r - c l a s s , t h e 1970 y e c r - c l a s s a l s o a p p t a r s t o have
been r e a s o n a b l y good, while t h e 1971 :>nd 1972 y e z r - c l a s s e s appear t o have been only
poor.
Curing t h e 1975/76 sb'ason t h e age d i s t r i b u t i o n was dominated by 3-yeas old and
6-year o l d fish.
kortalitg cslcuiations:
The t o t a l i n s t a n t a n e o u s m o r t a l i t y
from t h e above age d i s t r i b u t i o n s ,
has been c a l c u l a t e d
Because of the wide v a r i a t i o n s i n c z t c h p e r e f f o r t
t h e m o r t ~ ltiy fi w r e s l s o v z r i e s c o n s i d e r ibly.
was 0.46
(2)
The a v e r a t e r a t e f o r t h e l a s t t h r e e
(ice. t h e w e r a g e t o t 3 1 c a t c h of a d u i t h e r r i n g s p e r year >?as s b s u t 75%
of t h e a d u l t p o p u l a t i o n ) .
Fat Content
---
and Ember p e r kilogram:
filthough t h e main f i s h ~ r yon t h e riorth-west
coast
i s based on an autumn ~ ~ a r m i ncomponent,
g
a t times t h e r e i s an a d d i t i o n a l w i n t e r / s p r i n g
Spapming component lxnded.
Because of t h i s t h e r e were s t i l l o c c a s i o n a l l a n d i n g s of f u l l
f i s h i n t o December with r e s u l t i n g h i g h f a t c o n t e n t f i g u r e s .
Eowever a f t e r spawning was
Cornvlete and a s t h e f i s h c c n t i n u e d t o u t i l i s e ; h e i r f a t r e s e r v e s , t h e f a t c o n t e n t
g r a d u a l l y decreased and reached a minimum f i g u r e of
3.e: i n l a t e Februzry.
The a v e r a g e
f . t c o n t e n t (based on f i l l e t s ) and t h e numbers of f i s h p e r kilogramme a r e shown i n
Table 2,
'PEST COAST
Small q u a n t i t i t s of h e r r i n g s we=
and
l a d e d on t h e west cc.ist du-ring t h e summer s , , h t h s ,
examination of t h e s e showed t h a t t h e y belonged t o the ssaae r a c e a s t h a t on which
t h e a u t u m spawning f i s h e r y i s based,
t h e October-ld~rch p e r i o d ,
? a r t i n .the f i s h e r y ,
However t h e main l a n d i n g s took p l a c e d u r i x
It was a t t h i s time t h a t b o a t s from o u t s i d e t h e a r e a t o &
. b i l e t h e nmiber of b o a t s e n g ~ g e di n pair-fishing v a r i e d
c o m i d e r a b l y , ss many as n i n e t e e n p a i r s landed f i s h it Gaibbray c?uring t h e m a h se,s(!n.
.;ome landings were also m,:de a t Rosaveal,
The monthly l a n d i n g s of h e r r i n g s , the tor,al
v a l u e and the average p r i c e p e r c r a n s i n c e t h e f i s h e r y s t r t e d i n
1969/70 are shornI
below in T - b i e E,
Table 8:
I
: A s h a s a l r e a d y been mentioned, a s many a s
p a r t i n the fishery,
38 boats took
Because sf weather and t h e h e r r i n g f i s h e r y iri o t h e r a r e z s , ho"ieves
s e v e r a l of t h e s e p a i r s made o n l y o c c a s i o n a l l a n d i n g s ,
The t o t a l e f f o r t i n t h i s area
has not shown any dramatic change i n t h e l a s t t h r e e y e a r s and t h e c a t c h p e r e f f o r t
would i n d i c a t e t h a t t h e t o t a l s t o c k has a l s o r e m i n e d reasonably s t a b l e .
,
1
:
S c i e n t i f i c examinations of* th? h e r r i n g s landed a t Galway
vjere continued d u r i n g 1gii5/76, u s i n g t h e sane methods a s on the north-west
coast,
A
t o t a l of 700 f i s h 5:as aged and a f u r t h e r 3*300 measured and s u b s e q u e n t l y converted t o
I
ae;ee
:
I n t h e absence of a l o n g s e r i e s of c a t c h p s r e f f o r t d u t a i t i s
dit'ficu1.f; t o a s s e s s the s t r e n g t h of recruitment.
However from an examination of the
percentage age d i s t r i b u t i o n , shown i n Table 10, i t would sedm c l e a r t m t r e c r u i t m e n t
t o t h e Galhay h e r r i n g s , l i k e t h a t o f f Donegal, has been poor i n r e c e n t y e a r s .
I t would
:iis o appear t h a t the major r e c r u i trnent t a k e s p l a c e when h e r r i n g s a r e f o u r y e a r s old
wnich
L ~ t e rthan in o t h e r Irish. f i s h e r i e s .
I'he 1971 y e z r c l a s s
(i.3.
five-year oid
h e r r i n g s i n the i 9/5/76 s e a s o n ) appears t o be t h e s t r o n g e s t y e a r c l a s s t o r e c r u i t i n
recent years.
:
N o r t a l i t y @ a l e u l a t i o n s based on t h e age d i s t r i b u t i o m and
I
c a t c f i / e f f o r t d i t e f o r the p e r i o d 19'13/74 and 1975/76 show a n average t o t a l m o r t a l i t y
co-efilclent
of Z = 0.27,
which corresponds a?proximately t o an average a m u a l removal
I
o f 22$ of t h e a d u l t stock.
Table lo-:
I
Precentage age d i s t r i b u t i o n ( y e a r s ) of h e r r i n g landed n t Gzlway
-'I 970171 -
1975/76
Years
I::TZ;IN;,TIOYIL
ASPECTS OF THE F,RRING
ILternatir-:nal Catches:
--
~ I S H G R I ~OFF
S
THE NORTH ',TET ~,I$II i~~~~
$0 !,,;TS
i t was ;-iointed out i n l a s t y e a r ' s Report Fishery :,c?f-et Ko. 72
t h a t f o r t h e purpose of stocli mmagement t h i t h k r c i n g c s t c h e s l l n d e d a t D o n i g l l ; o r t s
I
I
a r e r e p o r t e d t o t h e North A t l a n t i c F i s h e r i e s Cmrnis:;ion a s having cons from the a r e a
I
VIA, The lower boundary of V I A runs a c r o s s Donegai Bay, so t h 7 t i n a c t u a l f a c t c a t c h e s
,
i n VIA t a k e n from the :;tags
t o an a r e a known as VIIb.
of Brozdhaven a r e a , should n o t be a l l o c t e q t o V I
,
i?ut
Area V I I b extends south1;ards t o the s o u t h of the Shennen
I
I
I
I
I
i
I
A t t h e uiorncnt i t i s not p o s s i b l e t o
and t h e r e f o r e i n c l u d e s t h e Galway f i s h e r y .
determine t o what a r e a l a r g e m o u n t s o f t h e h e r r i n g s landed a t t h e Donegal p o r t s
The t o t a l c a t c h t a h e n r'rom a r e a V I A has been r e s t r i c t e d by hT.lF@ s i n c e 1975
belong.
but s o f a r no r e s t r i c t i o n s have been imposed on a r e a V I I b
-
mainly because of the s m a l l
l
(The t o t a l c a t c h e s txken by c o u n t r i e s i n
c a t c h e s made i h e r e by c o n t i n e n t a l f l e e t s ,
each a r e a s i n c e 1966 a r e shown in Tables 1 I and 1 2 ) .
I n 1575 holtieves a Dutch f l e e t
l o c a t e d h e r r i n g s i n a r e a V I I b , west of Eagle I s l a n d , and i n a s h o r t b u t i n t e n s i v e
f i s h e r y removed n e a r l y ? Q,OQO t a n s , mainly d u r i r g t h e months of .-:ugu-.t al2d September.
his, t o g e t h e r w i t h i n c r e a s i n g
USSR catches, % r i l l c e r t a i n l y encoara>ge an i n c r e a s e i n
e f o r t i n this p ~ r t i c u l a rp a r t of a r e a V I I b and a l s o i n t h e l o s e r p a r t of a r e a VIA
( ~ , e ,t h e Stng.; o f Broadhaven a r e a ) ,
The t o t a l c a t c h which s h o u l d be t a k e n from a r e a V I A for
:
h2s been s e t by E . ' F ' C a t 455,200 t o n s and i36,OW t o n s r e s p e c t i v e l y .
1975 and 1976
The s c i e n t i f i c
a d v i c e ;n what c n t c h s h o u l d be t a k e n f o r both t h e s e y e s r s was 156,000 and 66,OrX)tons.
'?he a c t u a l c a t c h i n 1975 was approximately 129,0013 t o n s ,
I
,
I r e l a n d q s quota i n t h i s c o t a l
a i l o ~ i a b i ec z t c h i ~ 13,700
~ s
t o n s and 12,700 t o n s i n 1975 and 1976 r e s p e c t i v e l y and our
cetch i n
1975 ~ r a sapproxim t e l y 8,450 t o n s .
1977 w i l l probably be about 83,000 t o n s ,
The rec~mmei~ded
s c i e n t i f i c catch f o r
This has b r e n i n c r e a s e d s l i g h t l y o v e r t h e
2 976 f i g u r e n s i n l y because of d e c r e a s e i n the t o t a l c-.tch I n t h e u r e a and because
there i s no evidence of any d e c l i n e i n t h e r e c r u i t m e n t l e v e l .
However i t does n o t
appear l i k e l y t h a t c a t c h e s will e v e r be allowed r e t u r n t o t h e h i g h l e v e l of 1970-1
974.
It would seem a d v i s a b l e t h e r e f o r e , from t h e I r i s h p o i n t of view t o c o n t r o l o u r e f f o r t
r
i n VIA a t about t h e p r e s e n t l e v e l u n t i l such time a s a n o t h e r e x c q t i o n a l y e a r c l a s s
e n t e r s t h e f i s h e r y , and t h e n f i s h t h i s a t a h i g h e r r a t e f o r a period.
The h e r r i n g
s t o c k i n V I I b c , i n s p i t e of s m a l l e r c a t c h e s , seems t o be c-ipable of some f u r t h e r
exaloitation.
I
Howe~eri t s h c u l d be remembered t h a t because i t i s now t h e only a r e a
:.h.Lch i s v i r t u l l y ;;ithout any r e s t r i c t i o n s , it s h o u l d be c a r e f u l l y g u a r d e ? and
I
monitored.
Up t o 1975 I r e l a n d was i n f a ~ tth e o n l y country t h ~ c
t onsistently fished
I
t h i s a r e a ~ l n dt h i s f a c t s h o u l d bt: borne i n mind i f a q u o t : ~system based on h i s t o r i c a l
c:,tches should be i n t r o d u c e d f o r t h i s a r e a .
Table 11:
T o t a l c a t c h e s of h e r r i n g ( m t r i c t o n s ) in D i v i s i o n VTa, 1966-1975
Belgiun:
Englend
Faroes Bz Denmark
France
Geman Eem Rep.
"
Fed,Rep.
Icelmd
Irnl~fd
FletherZanda
Nomay
Poland
ScotSmd
USER
251
-
69,363
-
*
1975 f i g u r e s a m preliminary
Table 12:
Total catches of h e r r i n g ( m e t r i c t o n s ) i n D i v i s i o n VIIb-c 1966-1975.
*
Provisional catches for 1975
~ u o t a sand r e c o r d e d c:i ~ c h e sfrom c o u n t r i e s f i s h i n g i n VI-4
3,COO
The a u t h o r would l i k e t o e x p r e s s t h a n k s t o all those who s u p p l i e d
data and inf'ormation f o r t h i s paper and also t o t h o s e people mho
s u p p l i e d samples of h e r r i n g s f o r examination,
Kennedy, T.D.
and Molloy,
a. (1975).
H e r r i n g I n v e s t i g a t i o n on the
North-West and West c o a s t s 1975-76
F i s h Leaflet iio, 72,
Department of A g r i c u l t u r e and Fisheris s ,