NOT TO BE CITED WITHOUT PRlOR REFERENCE TO THE AUTHORS
C.M. 1998/0:46
Deepwater fish and fisheries
International Council for the
Exploration of the Sea
The "rasco": a gillnet fishery for Anglerfish (LophillS piscatorius L., 1758 and L. budegassa
Spinola, 1807) in the Cantabrian Sea (ICES Division VIIIc)
By
P. Pereda, A. Punz6n and J. Landa
Instituto Espanol de Oceanografia. PO Box 240. 39080 Santander. Spain
-.
ABSTRACT
In Northern Spain a specially designed giIlnet for fishing Anglerfish is used (L. piscatorius and 1..
blldegassa), mainly at 100-800 m depth. This gear is estimated to catch up to the 40% (1980-1996
average) of all Anglerfish caught in ICES Division VIIIc. This document not only describes the gear
itself, but also the fleet which works with it.
Due to its mesh size (280 rnm) this is s a very selective gilInet and anglerfish relative frequency is
one. The anglerfish makes up 97% of the total catch landed using this gear. The second best
represented species is skate, whose relative frequency is 0.11 and makes up 1% of the landed catch.
The landed catch of anglerfish is composed of specimens of over 30 cm. The mean length of L
piscatorius is 66 cm, while L. blldegassa mean length is 57 cm.
Discards of this fleet are mainly composed by fish in poor condition and occasionally invertebrates
with no commercial value.
Key words: Gillnet, Anglerfish, LophillS blldegassa, LophillS piscatorillS, catch, Cantabrian Sea.
1
--------------~---------~----
INTRODUCTION
Approximately thirty years ago, a direct gillnet fishery for anglerfish (Lophius budegassa and L.
piscatorius) began over the continental shelf of the North of Spain. Previously, the anglerfish had
only been taken as a bycatch of trawl catches. The fleet considered in this paper is that of the
Northern Spanish ports and operates in the fishing grounds of ICES Division VIIIc. The historical
roots of the anglerfish fishery are in the fishery targeting lobster when working in rocky bottoms
and Squatina squatina 1. 1758, tope (Galeorhinus galeus 1.) and other fish when working in
smooth bottoms (Rodriguez Santamaria 1923).
Small vessels normally working close to the coast make up the fleet, although they sometimes they
move out to fish over the continental slope (500-800 m). These vessels, which work with 'rasco'
(gillnet for Anglerfish), alternate this activity with other gears such as gillnet And in the coastal
season they even use hand lines to fish for mackerel, cerco for anchovy or currican for tuna, mainly
bluefin (Pereda and Villamor, 1991).
Annual landings of monkfish as a whole using rasco present two very distinct periods in the last
fifteen years. In the 80's catches of both species were 2 400 t on average, whereas in the 90's the
average falls to 930
t-
MATERIAL AND METHODS
In recent years the catches and distributions of landings have been obtained in the framework of the
project: "Improvement of data collection for stock assessment in Sub-areas VII,VIII, IX and X.
Study Project DG XIV N° 94/013" co-financed by the EU and the IEO (Anon, 1998). In preceding
years, from 1980 the IEO had its own sampling program in ports and wholesale markets.
Of the landings in 1996, 955 were sampled to obtain the catch composition in relative frequency
(number of fishing trips in which one species is landed divided by the total number of fishing trips)
and as a percentage with respect to the total landed with this gear.
The length distributions are obtained from length samplings carried out at the time of landing
catches. The type of sampling is random stratified, taking the vessel as a sampling unit. Length
sampling is carried out in the ports in which rasco landings are more representative: Santona, San
Vicente de la Barquera, Aviles and Cedeira. Length samplings obtained are pondered to total
landings of each species and month for each port, the sum of the ports sampled is pondered to the
total catch 0 f the area. Landings are sp lit by species based on their relative proportions in market
samples.
Effort has been quantified as the number of fishing trips monthly between 1994 and 1996, these
being obtaining directly from the sales sheets of landings or provided in the form of a table by the
Fishermen's Associations, before being processed in the laboratories of the lEO. Due to the fact that
in some ports there are gillnetters targeting hake and others fishing for monkfish, putting the
landings down to one gear or another is done according to the catch composition landed. CPUE
(catch of each species divided by effort) was obtained as the mean for the period [994 to [996.
2
--
RESULTS
Description of the Gear
Gillnets are based on a woven net which prevents the fish from passing through, the fish becoming
trapped in it. These gears, once lowered, remain in position until they are brought in??? (Gonzalez
et al 1986). Gillnets are made up structurally of sections of connected net which remain vertical by
means of two ropes called "relingas", one being the "relinga de plomos" along the lower part, which
acts to weigh down the net, and the other "relinga de flotadores" along the upper part with cork or
small synthetic buoys. The sections of net (pieces of net making up the gear) are made from
different materials such as nylon due to their great resistence and durability, Natural fibres such as
caiiarno or cotton are no longer used. The set of sections is called the "andana" or "linea", and its
extremes are marked at the surface by senda buoy (Puente, 1993). The weight of the gear is mainly
determined by the weight of the lower relinga or of the lead weights (250 gr each in the case of the
gill net for anglerfish ) in such a way that the gear remains vertical at the bottom.
In the gillnet for Anglerfish each section is denominated 'rasco' (figure 1), with an estimated price
per "rasco" (1 piec~ or section) of around 1800 pts, approximately equivalent to 11 euros. The
length of each "rasco'~is about 50 m and the total length of the gear varies according to the TRB of
the vessel. Thus, vessels of up to 10 TRB can work with gears of 7,000 m, vessels of 10 to 50 TRB
with 9,000 m and with more than 50 TRB the maximum sized gears of 11,000 m are possible. The
height of the gear carulOt be over 2.5 m, which corresponds to a height of nine gaps. The gear is
fixed to the bottom by means of a anchorage, called "rezon" in the shape of a rake at each extreme
of the line. The mesh size, defined as the distance between two opposing vertices of the extended
gap excluding knots, measures between 280 and 290 mm measured when wet, the minimum
measurement permitted by Spanish legislation.
rFloat
..~a~.; ··,,0·· .. -1't ..... -••- ••,I'tD1\.. '~
~
i \ ~j'
\
,. 'J 1,;\1'\\
.' i\~/\ 17\]\1
,,'
"'," '-, '. \/ \ j \;1 " '(
A i \ X '\' ,:, I
i
" /' , \ i' X/\
~i ,/ \/ \- '. \ Y . I \ \ / \ (
Ie.' '/./ \:,
Y. ,<' Uesh
280 III1t
.
, \ ".
X. l J XX}\ ~X.J.:
/ ~l\! /\/l\!'y\.\(\.;y );\/,/1/'\ ,,,".\' \'
I\! \
./
v
f
;< >c-0
-!
•·
1
./
.
:1
,?,
~
,;r
,""
-,
r/ ':( ~
til '.)I " ,
',,' It '/ .~ 'i (
;( l' ~ ',' \
.'
\'
'(
!',./. . \\,/\,,'1\'1/'\/",
,!, /\ !'\, l(/\/\/Ixi\;\
."
v '.{ ,\",I ' , :X ~','rI',1. ",.(
"x, A
\ " I ',...
\ "
l. .:t, (" , .\ / ',',
.1\.\
1,\/\/""\1 . . ; .. ',,/ . . /\',,, \/\ \ 1 \ / \ .
\.
{,'
1\;
~'l \,' './ .,'. '( ,/
V 'i {"i 'i ,J X" \(' \'/ ' .~ 'j'
t ,\;, .(. .
\
\ A. :~\ ;\ ./ \ /' :' '. 1\. :' \ ,/ \ I\," \ .I \, ..... \ I', ' \,... ',.' " 1 ,,' I .
(' \'
....
''/,,'
(
\,'
',I 'I' '(
., '1 'I' .; \! y' "
(
" ...
(, (
f.
I!~;{
"J."
't
'......
\
//\ /\ l'\ /\ /' ..... \.,. \
'
.. (
l\, (\; \ / \1 \ / \ :' \: \. ', ....
l /, ,\ ,'.'., '!
'-t
~
I
I
'I
,/ ""~''''- 51/\! \ \~'{L :: It:::;t~<:~~~
~~
l. . /\
-- "--...=
, " . ,~::., : . :.. ', ,,:'~', .. ,
.,'
,',
~
-'-'-:'~"" .... :.,
,
....,',- ,-:~.
.
r' ,
. (j;:v:::::;
~~
'.-'"
'.'- '
"
.
Sinker
Figure 1. Scheme of gillnet for Anglerfish
,,
Gillnetters begin work at around four o'clock in the morning when they leave port for the fishing
grounds They return at between four and eight in the evening. The number of fishermen per vessel
variess according to vessel size (length and tonnage). Pereda and Villamor (1991) report the number
of people per vessel in the Cantabrian Sea between 3 and 10. The gear always works for more than
24 h, and it is quite usual for it to spend between 2 and 8 days at the bottom. The depth at which it is
used varies between 70 and 800 m approximately, the mean value being around 400 m depth.
Once the vessel arrives at the buoy the gear is lifted aboard and the fish removed from the mesh. In
a gillnet the fish are literally "enmeshed", that is to say, they are retained by the mesh which be tight
to the body (Pope J. A. et al., 1983). As the fishes are extracted from the net they are opened and
gutted. Although normally all of the guts are extracted, sometimes part or all of the liver is left,
mainly when dealing with small sizes or when vessels from ports in which fish are sold with the
Ii ver intact.
By-catch and discards
The target species is -anglerfish (L. piscatorius and L. budegassa) whose frequency of occurrence is
1.0. Accompanying species, although in very small qtlantities, are made up ofrays (Raja spp), hake
(Merluccius merluccius), Scorpaena sp., Turbot (Psetta maxima) Greater fork beard (Phycis
blennoide) arid Horse mackerel (Trachunls trachurus). Occasionally some specimens of European
Lobster (Hommarus gammarus) and Lobster (Palinurus elephas), Lithocarpia sp, lYlarthasterias
glacialis, Cidaris cidaris are caught. The species composition of the landings is presented as
percentage of the total landings in figure 2 and as frequency of occurrence in figure 3.
Discards take place when fish are in poor condition. This is usually due to the gear having remained
longer than normal in the sea as a consequence of bad weather, which prevents vessels from moving
to fishing grounds to lifted the gear. Discards also occur of invertebrates of no commercial interest
such as: Geyon longipes, Paromola cuvieri, Lithocarpia sp., Marthasterias glacialis, Cidaris
cidaris, Pagurus prideau.xi, etc
In 1994 the Instituto Espaiiol de Oceanografia carried out a program to assess discards among
fishing gears working in the different ICES areas, including gillnet for angerfish. The results of this
program (including both gillnet for Anglerfish and "volanta" or gillnet for Hake) give discard values
of 38% in weight of the total discards for L. picatorius. For L. budegassa dicards made up 3%
(Perez et al. 1996).
4
?"lgel1us eryt:inu5 " +
!,
Pagellus boqaraveo J +
I
Fagellus acarne J+
DiploduS 5.0.
B.:aryx 5.0.
i
i O. 01
j
0.01
s~uamosus
~ 0.01
Platychtys flesus
j O. 01
Centrophorus
I
I
Deania calceus
0.01
Polyprion americanus
0.01
Trachurus trachurus
0.02
Pollachius sp.
0.02
Conger conger
0.02
Solea inugaris
0.02
Sepia off lcinalis
0.03
Mullus surmuletus
0.04
Phycis blennoides
10 . 04
Cetrosc~mnus coleolepi~~
Isurus ox:{r.cinchus
Psetta maxima
iI 0.11
1
0 18
.
Scorpaena scropha
1 0 . 23
Herluccius merlkuceius
-J, 0.65
I
I
Raja sp. -11.05
~11.70
Lophi'..;s bud8gassa
85.81
i-ophius pi sea todus .! .- _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
L~
o
10
20
30
40
50
60
70
80
90
Figure 2. Total landings in percentage
5
Plarychrys flesu.s i +
Diplodus sp.
Pagellus eryrrimu
j
+
i+
I
Pagelius bogaraveo
+
Pagellus acame
+
Cetroscymrru.s coleolepis: Deania caicetls
+
CenrrophonJ.s squamosus
+
-.
Trachunts trachurus
+
PollachitlS sp.
l'
Conger conger
+
PoLyprlon americarru.s
0.01
Sepia officinalis
0.01
lsurus oxyrrtnchus
Solea vulgan"s
Beryxsp.
iWullus mnnuletus
Phycis biennoides
Psetta maxima
Sco~aenascropha
r
OI
0.01
I
r'
0.01
r
0.02
a OJ
.
~06
}.tferlucciUs merlkuCCIUS
0.10
Raja sp.
a.11
1. 00
Lophius sp.
.0
.2
.3
.4
.5
.6
.,
.a
.9
:.0
Figure 3. Frequency of occurrence.
6
Catch Trends
Annual mean catch of 1. piscatorius in the 80's was 2000 t, whereas in the years considered in the
90's it was 800 t. 1. budegassa is less represented in catches than 1. piscatorius, the mean catch in
the 80's coming to 400t and in the 90's 140t. In 1989 the catch was as high as 1,010 t. Figure 4
shows the evolution of catches of the two species since 1980.
Landings (t)
8000
7000
6000
5000
4000
3000
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
- .... -Gillnet for Anglerfish (L.piscatorius) -+-Gillnet for Anglerfish (L.budegassa)
--Total landings (t)
(Trawl+GUlnet)
Figure 4. Evolution of the catches of 1. piscatorius and 1. budegassa of the Southern Stocks. Data
from ICES W.G. on the assessment of Southern Shelf Demersal Stocks.
Length composition of the catches
Length composition of the landings of 1. piscatorius and 1. budegassa caught by the Spanish gillnet
fleet for Anglerfish in the years 1986-1996 are shown in figure Sa and 5b respectively.
It is seen that in both species the width of the length range covered by rasco is quite regular
throughout the decade. The landed catch of Anglerfish is composed of specimens over 30 cm. L.
piscatorius reaches a greater maximum length than 1. budegassa (Landa et al 1998), the largest sizes
observed in the catch being 148 cm for 1. piscatorius and 105 cm for 1. budegassa.The mean length
of L. piscatorius was 66 cm during the years 1986-1996. The modal length was particularly small in
1991 and 1993. Lengths of specimens of L. piscatorius are greater than those of 1. budegassa, the
mean length for this latter being 57 cm during the same period, remaining around this mean with only
slight variations throughout the years considered (figures 6a and 6b).
7
40
3IJ
1986
35
3IJ
1992
25
20
25
15
20
15
10
10
5
5
0
0
25
IS
" " " " "
lS
"
10'
"'
'25
'0
J5
'" '"
IS
" " " " " " " "
'os
'IS
'25
1
1981
13S
\45
1993
•
30
5
"
•
20
3
"
2
10
0
0
IS
" " " " " " "
"
'os
'IS
'"
'" "'
SO
IS
25
" " " " " " "
10'
'"
'2$
•
1986
10
'" '"
'994
5
60
50
•
40
3
3IJ
2
20
10
0
0
IS
"
" " " " '" "
3$
10'
'" '"
'"
''''
18 T
16
13'
t
"-
..'
121
10 I
3$
.,
" " " '" " '"
II!! 12:1
'3$
",
liS
11$
\45
,...
5
3
'r
47
2
o
0 4 - -....IS
2:1
JS
45
5S
6$
15
s::i
~
L~
tLS
L2!i
9-
lJS
145
1990
,1++
51
!j
2S
1$
45
55
6!i
75
S$
9$
[OS
125
1
,
1996
5
5+
4
.~
3
~
2
2 1.
1
•
"
4
,f
3
IS
~
o '----'--'"
U
2S
3S
45
o -'-'------'jj"
liS
75
~S
9S
10$
115
125
lJ.l
145
1.:S
25
35
45
5S
65
15
is
~
lOS
11!5
12:1
IlS
145
25 20
15
10
5
o
Figure 5 a. Length composition of L. piscatorius caught by Spanish gillnet for Anglerfish in Villc
ICES Divisions.
8
20
1986
7
6
r
1992
5,1
15
4
1
3l
10
2lI
5
I l
1 ~
o~I~~~II~lu~I,,~JII~
__~__
0+--_ _-
:m
10
;~30 1
19B7
16
14
JO
40
50
60
70
80
90
I
100
1993
121
'0 1
25
20
I
a1
61
.1
15
1
2~
0.'--1_ _~"-'-'"
10
70
1988
~
ro
40
~
~
m
w
~
10
9
60
a
'994
I
50
7 1
40
6
5
30
100
4
3
2
20
10
~LI--~~--~-L~
o -h~~_~--'""""
25
'995
'989
20
15
21
10
1
I
10
54
'990
ID
JO
40
~
60
W
W
90
3
100
'996
I
J
I
21
!
[()
5-
I
20
30
40
$0
60
10
30
90
100
,....
I
4T
3'I,
2~
I
1 .l.
0-------'
Figure 5 b. Length composition of L. budegassa caught by Spanish gillnet for Anglerfish in VIIIc
ICES Divisions.
9
80
75
70
65
f
f
I
1
..
601
55 1
I:; 1
50
45 1
40 I
35
...
T
ci
r
30
1985
I
i986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
Year
1_ _ _
Mean ... El- •• Mode
I
Figure 6 a . Mean length and mode evolution of L. piscatorius caught by gillnet for AngJerfish
80,---------------------------------------------------.
"
~~
60
E. 55
:; 50
45 ...
40 e(
35
?
_
V
13 ...... a
1
.....
~.'
.~ ~~
>
~•
.' .
......
...
"e('
.. """-0.
L---~
'-.. /..
.~ .. '
'ci
I
~
"·1
1Il
I
1
'
30L---~----~--------------~--~~--~------------~
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
Year
i--Mean ... E]. •• Mode
Lineal (Mean)
i
Figure 6 b . Mean length and mode evolution of L. budegassa caught by gillnet for AngJerfish.
10
Catch per unit effort
The evolution of the monthly average CPfJE from 1994 to 1996 is presented in figure 7 media de
[os tres arros by specie. A general and progressive fall in CPUE of L. piscatorius can be seen
throughout the year, its maximum values appearing in the first quarter and minimums coming in the
last. With respect to the CPUE of L. budegassa (figure 7), the ligure remains approximately
constant throughout the year (annual mean (PUE of 0.03), reaching maximum values in February
and December.
0.25
1!
0.2
w
a. 0.15
u
-'''"""
<II
«>
L. p;scatodus
--
:::l
0.1
0.05
0
0
.~
2
3
4
5
6
•
7
8
9
10
11
12
Month
Figure 7. Average CPUE (1994-1996).
DISCUSSION
The gillnet fa angerfish is a highly selective gear with respect to species, due to Doth its design ar,Q
its working areas. It catches almost exclusively L. piscacorius and L. budegassC!., while remaiiling
catches are very small and representation or other species in landings is highly limited. The
reduction of the [andings in the 90' was probably probably due to an overfishing during the 80', this
reduction represent a 60% in the landings of L. piscalOrius and 67% in L. budegassC!. ..
The range of depths that the fleet covers the areas of bathymetric distribution of both species. The
r.vo spec;es, nevertheless, have different bathymetric ranges. L budegassC!. has a [ower range of
disrnbution and greater abundance at lesser depths, at between 70 and 200 m approximately. L.
piscalOrius, 0[1 the other hand, has a greater range of distribution and a g;-e2ter abundance at gye2t
depths, its highest abundance appearing at between 100 and 1000 m approximately. Thus, although
raseo covers the area of bathymetric distributio[1 of L. budegassa, it works mainly in the area of
distribution of L. piscatorius. This is shown by the greater proportion of catches orchis species.
Il
Whereas the CPUE's of L. budegassa remain more or less constant throughout the year, an increase
is observed in CPUE's for L. piseatorius in the first part of the year, which seems to indicate a
higher abundance of this species in the area. The fleet tends to work at greater depths at the
beginning of the year ( J. Landa and A. PUnz6n, pers. com.) when the highest concentrations of L.
piscatorius appear. This characteristic may corroborate the hypothesis of a migration of these
species to deep water in winter (Duarte et aI., 1998).
REFERENCES
ANON. 1998. Final Report of the DG XIV Project: "Improvement of data collection for stock
assessment in Sub-areas VII,VIII, IX and X" . Study Project DG XIV N° 94/013.
DUARTE R., M.AZEVEDO, J. LANDA and P. PEREDA. 1998. Reproduction of black and white
anglerfish (Lpphius budegassa, L. piseatorius) in the southern stock (ICES Divisions VIIIc
and IXa). ICES C.M. 1998/0:23.21 pp. Deepwater fish and fisheries.
GONZALEZ, S., A. LAViN, V. ORTIZ, P. PEREDA, F. SANCHEZ Y B.VILLAl\10R. 1985. La
pesca en Cantabria. Ed. Gobierno de Cantabria, Servicio de Actividades pesqueras. 307
pp.
ICES 1997. Report of the Working Group on the assessment of Southern Shelf Demersal Stocks.
ICES CM 1998/Assess:4. 664pp.
LAl'IDA J., P. PEREDA, R. DUARTE and M. AZEVEDO. 1998. Growth study of white and black
anglerfish (Lophius piseatorius and L. budegassa) based on annual sampling from ICES
Divisions VIIIc and IXa. ICES C.M. 1998/0: 21. 39 pp.Deepwater fish and fisheries.
PEREDA, P. AND B. VILLAMOR. 1991 Artisanal fisheries in the Cantabrian Sea. ICES
CM.19911G: 30 Sess P.
PEREZ, N., P. PEREDA, A URIARTE, V. TRUJILLO, I. OLASO & S. LENS.1996. "Descartes de
las f10tas espafiolas en el las divisiones del ICES".: Datos Resum. Inst. Esp. Oceano gr.,
1996,2: 1-142.
POPE, J.A. , MARGETTS, AR., HAMLEY J.M. & AKYUZ E.F., 1983. "Manual de metodos para
la evaluaci6n de las poblaciones de peces. Parte 3: Selectividad del arte de pesca". F.A. 0.
Doc.. Tee. Pesea n° 41: 56 pp.
PUENTE RICO, E. 1993. La pesea artesanal en aguas eosteras vaseas. Colecci6n Itxaso N° 11;
Servicio de pUblicaciones del Gobiemo Vasco (Vitoria).191 pp.
RODRIGUEZ SANTAMARiA, BENIGNO. 1923. Diccionario de artes de pesca de Espana y sus
posesiones. Ed. Sucesores de Ribadeneyra S.A Madrid.
12