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The Spanish fishery for Loligo: recent trends
E LS EV I E R
Fisheries Research 21 (1994) 217-230
The Spanish fishery for Loligo: recent trends A. G u e r r a a'*, P. S~inchez b, F. R o c h a a alnstituto de InvestigacionesMarinas (CSIC), Eduardo Cabello 6, 36208 Vigo, Spain blnstituto de Cienciasdel Mar (CSIC), PaseoJuan de Borbrn s/n, 08039 Barcelona, Spain
Abstract The Spanish fishery for the loliginid squids Loligo vulgaris and Loligo forbesi is described, with particular emphasis on the period 1983-1991. During this period the landings of squid in Spain stayed at a relatively constant level of around 2200 t. The value of the Spanish squid landings increased throughout the 1980s and amounted to £9.7 million in 1991. The two species of squid are not treated separately in the official statistics, and therefore the percentage corresponding to each is unknown; nevertheless, in the maritime regions of the Mediterranean, L. vulgaris is practically the only species landed, while in Atlantic regions, both are landed, although L. vulgaris is more abundant than L. forbesi. Particular attention is paid to the analysis and description of fisheries and squid landings in Galicia (northwest Spain) and Catalonia (northeast Spain), during the period 19801991. In both regions, part of the landings correspond to trawling and purse-seine fisheries targeting finfish, where squid is caught as a by-catch. There are also important seasonal artisanal fisheries where the target species is squid. Landings have shown a marked seasonality; being more plentiful in summer and autumn. This resource does not show signs of overfishing. The present methods of fishing management are discussed, and proposals are put forward to modify some of these in order to avoid catching immature individuals of less than 200 mm mantle length. Keywords:Loligoforbesi; Loligo vulgaris; Spain
1. Introduction The Spanish fishery for loliginid squid comprises mainly of two species: Loligo vulgaris Lamarck, 1798, and Loligoforbesi Steenstrup, 1856. Two other species, Alloteuthis subulata (Lamarck, 1798) and Alloteuthis media (Linnaeus, 1758 ), are also landed in Spain, but in smaller amounts. * Corresponding author. 0165-7836/94/$07.00 © 1994 Elsevier Science B.V. All rights reserved SSDIOI65-7836(94)O2014-Z
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In 1990, neritic squid catches amounted to about 5326 t in the northeast Atlantic, mainly L. forbesi and L. vulgaris, whereas Mediterranean catches reached 10 582 t, mainly ofL. vulgaris (Food and Agriculture Organization (FAO), 1992 ). Loligo vulgaris is widely distributed in the Mediterranean and northeastern Atlantic (Worms, 1983; Guerra, 1992). While it is not an important species among the commercially exploited cephalopods in the world, it can be significant on a local scale (Guerra and P6rez-G~indaras, 1983 ). No major specialised fishery for Loligo vulgaris exists in the northeastern Atlantic, where it is mainly a by-catch of multi-species trawling fisheries, but there is a small artisanal fishery using hand-lines and home-made jigs (Worms, 1983; Guerra et al., 1992; Cunha and Moreno, 1994). In the Mediterranean, although L. vulgaris is not really a target species, it is rather heavily fished by Spain and Italy (Worms, 1983). Market prices for Loligo vulgaris are high, representing 2.05 % of the total turnover for fresh fish sales in Catalonia (northeast Spain) (Martin, 1991 ). In Spain L. vulgaris is highly appreciated and forms a part of the traditional diet of coastal and many inland populations, playing an important role in the local fish markets (Guerra and P6rez-G~lndaras, 1983; Guerra, 1984). Loligoforbesi is a common squid species in the eastern Atlantic and also occurs in the Mediterranean Sea, although its distribution is not fully established (Roper et al., 1984; Guerra, 1992). Loligoforbesi has been observed throughout the Mediterranean (Mangold and Von Boletzky, 1988) being scarce in the northwestern Mediterranean (S~inchez, 1985; Von Boletzky and Mangold, 1985 ), but relatively abundant in the Sicily Channel (Ragonese and Jereb, 1986 ). Loligo forbesi is the only squid species of commercial importance fished in waters of the United Kingdom, where it is landed largely, but not exclusively, as a by-catch from demersal trawl and seine-net whitefish fisheries (Pierce et al., 1994). It is also the only squid species of economic importance in the Azores, where the fishery involves an artisanal fleet equipped with hand-lines and homemade jigs (Martins, 1982; Porteiro, 1994). In Portugal, L. forbesi is caught as a by-catch in the multispecies trawl fisheries, together with L. vulgaris, but a local artisanal fishery also exits, employing hand-jigs (Cunha and Moreno, 1994). On the west African coast, the species is caught as by-catch in the multispecies fisheries in various locations (Burukovski et al., 1979; M.M. Fern~indez, personal communication, 1994). In the Mediterranean this species is mainly caught as a by-catch in the multispecies trawl fisheries. Data on squid fisheries in Spain have not been previously summarised. The broad aims of this analysis are to describe the current status of the Spanish squid fishery with particular emphasis on the period 1980-1991, and on the Galician and Catalonian fisheries. This work constitutes the most comprehensive study of loliginid squids landed in Spain. Information on fishing methods, the economics of squid fishing and trade in squids is presented.
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2. Materials
From January 1989 to January 1992, monthly visits were made to the main fishing ports in Galicia (northwest Spain) and Catalonia (northeast Spain). Owing to the lack of official statistics on squid landings since 1986, during these visits contact was established with the personnel in charge of the fishermen's cooperatives in the ports of these two regions, who provided data on the monthly squid landings and prices from 1980 to 1991, and also fishing boat skippers were interviewed. Data on squid landings in Spain by weight and by value from 1983 to 1986, were obtained from the Maritime Fishing Annual, which, inexplicably, is no longer published. Until 1991, these data, and data on squid landings in each maritime region of Spain (Fig. 1 ) for 1990 and 199 l, was obtained by consulting the files of several private companies at a national level. Although there is information available on the number of vessels, their characteristics and fishing hours, it is not possible to refer to fishing effort for squid, since the fishery is multispecific, and squid is caught as by-catch, the target species being finfish. Unfortunately, Spain does not record landings and fishing effort for single ICES 10° W N!
45 ¢
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'
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ATLANTIC OCEAN
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Fig. 1. Map showing the maritime fishing areas of Spain.
A. Guerra et aL /Fisheries Research 21 (1994) 217-230
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statistical rectangles, as occurs in other countries (e.g. United Kingdom; Pierce et al., 1994). All data were transferred to single PC-based spreadsheets, written using QUATRO-PRO V.4.0, which was also used to perform the analyses and to generate graphics.
3. R e s u l t s
The two main species of loliginid squids (L. vulgaris and L. forbesi) of fishery importance are not differentiated in the statistics. Both are sold together in the markets, obtaining similar prices and are marketed in similar ways. For this reason it is impossible to distinguish between the percentages corresponding to each of the species in the statistics. Nevertheless, the Spanish loliginid squid landings comprise mainly ofL. vulgaris, which is the most common species in the Atlantic and the only one present in the Mediterranean in relatively large quantities, but some of these landings are of L. forbesi, mainly those from the Spanish Atlantic coast (Cantabrian, Northwest and South Atlantic maritime regions; Fig. 1 ). Visits to the ports and interviews with fishing boat skippers allowed us to become acquainted with how the artisanal fisheries operate and their importance. These catches are not brought into the fish exchange and are not accounted for in the official statistics, owing to the fact that, in general, they are sold to local bars and restaurants or are consumed by the fishermen themselves. These fisheries use hand jigs and beach seines in Galicia, and hand jigs in Catalonia, where part of the artisanal landings (mostly with trammel nets) are brought into the fish exchange and accounted for in the official statistics. The general trend of Spanish landings, (Fig. 2 ) shows that the landing levels of 10
35O0
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~
.7.5
i
.7
15 -~ 1
Landings A VNue
1483 1484 1485 1486 1~7 1488 1~J89 1490 1491 Year
.6.5 6
Fig. 2. Annual squid landings in Spain by weight and value (pounds sterling), from 1983 to 1991. Data only refers to trawling fishery.
A. Guerra et al. / Fisheries Research 21 (1994) 217-230
221
the loliginid squid fishery were relatively constant from 1984 to 1991 (2200 t year-l). The value of Spanish squid landings increased throughout the 1980s from £6.6 million in 1984 to £9.7 million in 1991. This value is very small in comparison with the value for finfish (Fig. 3 (B) ). Table 1 shows the loliginid squid landings for each Spanish maritime region (Fig. 1 ) for 1990 and 1991. The relative importance of landings of fish, crustaceans and cephalopods by weight (A) and value (B) in Spain from 1983 to 1991 is shown in Fig. 3. The percentages represented in both figures are the average values calculated for this period, which were practically constant (4.3-5.6% for weight and 6.3-7.1 for values). Loliginid (long-finned) squid represent 11.2% by weight or 22% by value of CEPHALOPODS (5.(7%)3~
CRUSTAGEAN(S2 ~ l ~ l . ~ SOTI-OM FiSH (313%)
I
Spain
PELAGIC FISH (61.5%)-~" ~
Weight ( 1983-1991)
CEPI CRUSTACE
PELAGIC FISH
Value (1983-1991) Fig. 3. Percentagesof Spanish landings for all species offish, crustaceansand cephalopods by weight (A) and by value ( B ) for the period 1983-1991. The percentageshown is the averagevalue calculated for said period. Table 1
Squid landings (amount in tonnes and as a percentage of total landings) in each Spanish maritime region for 1990-1991 Maritime Region
1990
Tonnes Cantabric
Northwest South Atlantic South Mediterranean Levante Tramontana (Catalonia) Balear
Total
165.8 461.3 569.8 291.3 348.2 250.7 49.1 2136.2
1991
Percentage 7.8 21.7 26.8 13.7 16.2 11.5 2.3
Tonnes 270.2 428.6 538.2 325.6 363.2 237.0 62.0 2214.9
Percentage 12.2 18.9 24.3 14.7 16.4 10.7 2.8
222
A. Guerra et al. /Fisheries Research 21 (1994) 217-230
Spanish landings of cephalopods (Fig. 4). These percentages are average values calculated for the period 1983-1991, during which the importance of loliginids was practically constant. Annual landings of squid caught in Galician trawling fisheries for the period 1980-1991 (Fig. 5) ranged from 218 t in 1988 to 550 t in 1980 and 1982. The total annual value of the catch peaked in 1986. Landings in the north area of Galicia (from Ribadeo to Finisterre; Fig. 1 ) represented about 50% of the total in Galicia from 1980 to 1986, but have experienced a dramatic decrease since 1987 (Fig. 5 (B)), while the landings from the south area (from Finisterre to La Guardia; Fig. 1 ) came to represent about 95% to the total landings from 1987 to 1991. From 1986 to 1991, the trawl squid landings in Galicia showed a marked seasonality. Landings were low during spring and summer, while there was an increase in autumn and winter (Fig. 6 ). In the trawling fisheries of Galicia both L. vulgaris and L. forbesi are taken together as by-catch of finfish. They are present in the fishery throughout the year from 100 to 350 m depth. L. forbesi is more abundant than L. vulgaris in the north fishing grounds, while in the south, the opposite occurs. A small scale directed hand-jig fishery takes place in inshore waters ( 10-60 m depth) of the Galician coast. This is a seasonal fishery, which extends mainly from May to September. This fishery is carried out by a numerous and mixed artisanal fleet, comprising about 1000 open boats, from 3 to 10 m in length, and only equipped with hand lines and home-made jigs. Fishing operations take place in daytime. Fishermen jig for squid only when the animals are found in relative abundance and when the weather permits. The crew comprises one or two fishermen, generally retired from other fishings. Most of the catches are of small, immature squids, and large immature individuals. These catches arc not regis-
SHORT FINNEDSQU[
JNEDSQUID(11,2%) CUTI]~FISH (13.5%)
OCTOt~USES
Weight
SHORT F {22.0%)
4%)
OCTOPUSES V;~lU~
Fig. 4. Percentage of Spanish landings for each type of cephalopods by weight (A) and value (B) for the period 1983-1991.
A. Guerra et al. / Fisheries Research 21 (1994) 217-230
i'lttilj 80
81
82
83
84
B5
86
87
88
89
90
223
gl
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8
C: 81
82
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~0. 250.
83
84
85
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Io
I~JI 80
.
86
87
88
89
gO 91
~ ~~
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80 81
.
. . . . . . . . . 82 83 84 85 86 B7 88 89 Year
IBm L oQs
go
91
180000
.leOOoo ,1~ ,~ooo ~ 40000
20000 0
J
Fig. 5~ Annual squid landings in Galicia by weight (t) and by value (thousands of pesetas) during 1980-1991. A, totals; B, north area; C, south area.
tered in the official statistics of landings. Generally, in the north, the small, immatt~re squid are L. vulgaris and the large immature individuals are L. forbesi, while in the south, only L. vulgaris is caught. They are sold directly to local bars and restaurants, or consumed by the fishermen. It is very difficult to estimate the amount represented by this seasonal fishery, but from our observations, it is 7090 t per month. Galicia also has another artisanal fishery which takes place inside the south rias
224
A, Guerra et al. /Fisheries Research 21 (1994) 217-230 100
!iD :
11
il 88
89 Year
90
1991
Fig. 6. Total monthly squid landings in Galicia duringthe period 1986-1991 (O, October; N, November; D, December). 700
3
600
"2.5
500 •~
-2
c
400 -1.5 ~
~ 300 200
-1 Landings ~
100 ~78' 1~80' 1~82' 1 9 ~ ' 1 ~
£ Million
' 1~88' 1 ~ 0 ' 1~, o.s
Year Fig. 7. Annual landings in Catalonia by weight and value (pounds sterling) from 1980 to 1991.
(from 3 to 40 m depth). This is a seasonal fishery which extends mainly from July to November. This artisanal fishery is operated by an artisanal fleet equipped with beach seine nets. It is a multispecies fishery where juveniles of several finfish species are caught. The catches also include immature Loligo vulgaris and immature and adult Alloteuthis subulata, which are the only two loliginid species that live and spawn inside the rias (Guerra, 1984). Squid caught with this type of fishing gear are of 50-150 mm mantle length (ML). These catches are not registered in the official statistics of landings. The catch is very variable from day to day, thus making it difficult to estimate the amount represented by this seasonal fishery, but from our observations, it varies from 5 to 10 t per month. The price of the squid from the Galician trawling fishery ranged from 530 to 873 pesetas kg-1 for the period 1983-1991, while the price of the squid from jig and beach seine fisheries ranged from 850 to 1600 pesetas kg- 1 for the same pe-
A. Guerra et al. / Fisheries Research 21 (1994) 217-230
N
0
225
Io o, o
&
"10
.¢_
._>,
8
50-
4030. 20. 10. 0
.................................................................................... ! L 1981 82 83 84 85 86 87 88
89
................... 90 91
Year
Fig. 8. Monthly landings ofLoligo vulgaris in Catalonia during the period 1981-1991 (O, October; N, November; D, December).
i
Trawl
~2 O.8 07t ~o,1
0.4 I
0.35~
Seine
~025~' 02~ O.lS-
Fig. 9. Monthly evolution of Loligo vulgaris landings in the port of Blanes (Catalonia) during the period 1986-1990 on three types of fishing.
226
A. Guerra et al. /Fisheries Research 21 (1994) 217-230
riod. This difference is due to two reasons: the superior quality of squid from jig fisheries, since it is landed fresh, whole and not skinned, and small squid being more highly regarded than large squid. In Spain, loliginid squids are used exclusively for human consumption. They are highly regarded in local and national markets. Annual landings of Loligo vulgaris in Catalonia (northeast Spain, from the French border to the River Ebro; Fig. 1 ) during 1980-1991 ranged from 624 t in 1980 to 200 t in 1990, while the price of the squid ranged from 350 to 1525 pesetas kg-~ for this period (Fig. 7). Monthly landings ofL. uulgarisin Catalonia during 198 I- 1991 (Fig. 8 ) showed a marked seasonality. Landings were much more abundant in summer and autumn than in winter and spring. The largest catch was generally obtained in October (50 t). Exceptionally, in August 1988, the catch was 92 t. During the past few years, the squid catch in spring has been almost non-existent. In the Catalonian statistics shown in Figs. 7 and 8, landings from all types of fishing gear are included. At the port of Blanes (Catalonia), three types of fishing gear are involved in this fishery. Trawls caught 85.9% of the squid, purse-seine nets 4.2%, while artisanal fleet (trammel nets) caught 9.9% where L. oulgaris is caught as a by-catch. The seasonal pattern of landings is very similar for all years (Fig. 9 ).
4. Discussion
According to our study and results obtained by Worms (1979) and Sgmchez and Martin (1993 ), it seems that Atlantic and Mediterranean Spanish stocks of Loligo vulgaris and L. forbesi are not likely to become a target species for a highly specialised fishery. The stability of the Spanish landings from 1983 to 1991 seems to indicate that the stocks are not over-exploited. Although the demand for loliginid squid in the Spanish market has been on the increase in recent years, it has been supported by other species, such as Loligo gahi from the Falkland Islands, Loligo pealei from the USA fishing grounds, Loligo opalescens from California, and Loligo duvauceli from the Indian Ocean, either caught by Spanish fleets or imported. As this loliginid squid is brought onto the Spanish market frozen, and local squid is marketed fresh, there is no competition between the products. The Spanish market is very strict: thawed squid is generally detected and sold as fresh only with difficulty. It may be thought that the dramatic decrease in loliginid squid landings in the north of Galicia from 1987 to 1991 (Fig. 5 ) was due to overflshing, but it is very difficult to demonstrate this since squid, in this fishery, is caught as by-catch of trawlers catching finfish. The apparent discrepancy between the seasonal pattern of squid landings in Catalonia and Galicia is misleading. Squid landings appear lower in spring and summer in Galicia (Fig. 6) since these statistics exclude the 90-130 t per month from the artisanal fishery. If this figure were included, spring and summer would
A. Guerra et al. /Fisheries Research 21 (1994) 217-230
227
have the greatest landings, as occurs in the Mediterranean (Fig. 7 ), statistics for which do include landings from the artisanal fishery. The seasonality shown by the squid landings in Galicia and Catalonia, with a greater abundance in summer and autumn, coincides with observations made by Pierce et al. (1994) in Scotland, and by Cunha and Moreno (1994) in Portugal. As indicated by Pierce et al. (1994), the seasonal pattern in landings (being unrelated to total fishing effort) may be regarded as indicating fluctuations in abundance. Young squid recruit to the fished population largely in the summer (JulySeptember). Peak spawning occurs between December and February in L. forbesi, whilst in L. vulgaris it peaks between December to April, but continues throughout the year (Guerra and Rocha, 1994). Thus the rising catches in the latter half of the year are maturing, pre-breeding squid and catches fall off prior the peak of the breeding season. As in Scotland (Pierce et al., 1994), in Galician and Catalonian waters it is unclear whether the seasonal decline in catches is a direct consequence of fishing or whether natural mortality or reduced catchability is responsible. Reduced catchability might occur due to horizontal or vertical movements into unfished waters (Guerra and Rocha, 1994; S~inchez and Guerra, 1994). Spawning areas of L. vulgaris and L. forbesi are not well known although egg masses are recovered from creel lines in Scotland (Lum-Kong et al., 1992), Algarve, south Portugal (Coelho et al., 1994) and Galicia (Guerra and Rocha, 1994) and breeding squid are caught in inshore waters. In the artisanal fisheries using beach seine nets, small, immature individuals of L. vulgaris (50-150 mm ML) are caught, which serves to indicate that recruitment of the species occurs mainly during summer and autumn. This agrees with biological data obtained by Guerra and Rocha (1994). In some of the Autonomous Communities in Spain (e.g. Galicia), there is a minimum legal size for squid landings of 100 mm ML. In accordance with the size at maturity of both species now established (Guerra and Rocha, 1994), it would be appropriate to increase the legal size to 200 mm ML. In recognition of the spawning season and the growth rates of both species (Guerra and Rocha, 1994), it may also be appropriate to establish a closed season for both species, at least from 1 December to 1 March. However, these measures could not easily be introduced, owing to social repercussions arising from the restriction of fishing effort. The measures currently in force on the Spanish coasts regarding trawling fisheries, which forbid trawling between the coast and 100 m depth in the Atlantic and!between the coast and 50 m depth in the Mediterranean, appear to be sufficient to prevent overfishing on squid. This fishery is directed at a number of species, and it is very difficult to adopt suitable fishing management measures for multispecific fisheries where squid is caught as a by-catch (Anonymous, 1993 ). The question of whether the squid Loligo vulgaris reynaudii resource in South African waters can be managed effectively was examined by Augustyn et al. ( 1992 ) in the light of developments in the fishery and knowledge of the resource gathered in recent years. These authors show that, although much more is known
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A. Guerra et al. / Fisheries Research 21 (1994) 217-230
than few years ago, many questions relating to the resource are still unsolved, as is currently the case with the L. vulgaris and L. forbesi resources in Spanish waters. To date, management of the resource in South Africa as well as in Spain has been conservative, and this can be justified in the case of short-lived species such as squids because there are no buffering effect of several age-classes and a stock collapse in any single year will have immediate and serious consequences (Augustyn et al., 1992 ). It has been geared to such rational or 'common-sense' measures as size restrictions, as well as a closed area for trawling from coastal line to 50 or 100 m depth. Although it cannot be claimed that these management measures have been solely responsible for the relative stability of the stocks, they have contributed to it. However, these long-term measures, all appropriate in the early stage of a fishery when knowledge is limited, should be replaced by more flexible alternatives as knowledge improves, as indicated by Augustyn et al. ( 1992 ). Short-term mechanisms may be applied. According to Augustyn et al. (1992) this implies that: (i) stock levels must be measured more frequently and accurately in future; (ii) the stock-recruitment relationships must be well known; (iii) although more is known about longevity, fecundity and other aspects of the squid life cycle, the effect of fishing activity on spawning squid and the effects of environmental changes must be examined. In the meantime, the management measure already enforced and perhaps effort control in the artisanal fisheries appears to be the best approach for management, although a more rational management procedure should be introduced to ensure that the decisions made are structured ones. One such approach is offered by the Leslie-Delury analysis (Beddington et al., 1990; Augustyn et al., 1993), which could be introduced as a way of managing effort and preventing overexploitation. Caveats are that the practical problem of real-time data input (catches) must be overcome, as indicated by Augustyn et al. (1992). In order to apply this solution in the Galician squid fishery a network of sampling has been organised to obtain accurate monthly catches.
Acknowledgements We would like to thank M. Rasero, A.F. Gonz~llez, M.T. Fern~indez, F. Casas and J. Alen for his efficient technical assistance and useful suggestions, and the people responsible for the Fishermen's Cooperatives and companies who helped us in obtaining information. This work was funded by the Commission of the European Communities within the frame of this EEC research programme in the fisheries sector (FAR, contract no. MA. 1.146 ).
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effectively? A synthesis of research on Loligo vulgaris reynaudii. In: A.I.L. Payne, K.H. Brink, K.H. Mann and R. Hilborn (Editors), Benguela Trophic Functioning. S. Afr. J. Mar. Sci., 12: 903918. Augustyn, C.J., Roel, B.A. and Cochrane, K.L., 1993. Stock assessment in the chokka squid Loligo vulgaris reynaudii fishery offthe coast of South Africa. In: T. Okutani, R.K. O'Dor and T. Kubodera (Editors), Recent Advances in Cephalopods Fisheries Biology. Tokai University Press, Tokyo, pp. 3-14. Beddington, J.R., Rosenberg, A.A., Crombie, J.A. and Kirkwood, G.P., 1990. Stock assessment and the provision of management advice for the short fin squid fishery in Falkland Islands waters. Fish. Res., 8: 351-365. Burukovski, R.N., Gaeuskaya, A.V., Domaneuski, L.N., Nigmatullin, Ch.M. and Panfilou, B.G., 1979. Main results of research on squids carried out by the Atlantniro in the CE Atlantic. ICES, 1979/ K:2. Coelho, M.L., Quintela, J., Bettencourt, V., Matto Silva, G.O. and Villa, H., 1994. Population structure, maturation patterns and fecundity of the squid Loligo vulgaris from southern Portugal. Fish. Res., 21: 87-102. Cunha, M.M. and Moreno, A., 1994. Recent trends in the Portuguese squid fishery. Fish. Res., 21: 231-241. Food and Agriculture Organization, 1992. Yearbook of Fisheries Statistics. Vol. 70, 1990. FAO, Rome. Guerra, A., 1992. Mollusca, Cephalopoda. In: M. Ramos (Editor), Fauna Ibrrica, Vol. 1. Museo Nacional de Ciencias Naturales. C.S.I.C., Madrid, pp. 327, 12 h. lam. Guerra, A. and Prrez-G~lndaras, G., 1983. Las pesquerias mundiales de Cefal6podos: situaci6n actual y perspectivas. Inf. Tec. Inv. Pesq., No. 102-104, 141 pp. Guerra, A. and Rocha, F., 1994. The life history ofLoligo vulgaris and Loligoforbesi (Cephalopoda: Loliginidae) in Galician waters (NW Spain). Fish. Res., 21: 43-69. Guerra, A., Rocha, F., Casas, F. and Fern~indez, M.T., 1992. Loligo vulgaris and Loligoforbesi (Cephalopoda, Loliginidae): their present status in Galician Fisheries. ICES, 1992/K:40. Lum-Kong, A., Pierce, G.J. and Yau, C., 1992. Timing of spawning and recruitment in Loligoforbesi (Cephalopoda: Loliginidae) in Scottish waters. J. Mar. Biol. Assoc. UK, 72:301-311. Mangold, K. and von Boletzky, S., 1988. Mediterranean Cephalopod Fauna. The Mollusca, Vol. 12, Paleontology and Neontology of Cephalopods. M.R. Clarke and E.R. Trueman (Editors), Academic Press, London, pp. 315-330. Martin, P., 199 I. La pesca en Catalufia y Valencia (NO Mediterrfineo): anfilisis de las series hist6ricas de captura y esfuerzo. Inf. Tec. Sci. Mar., 162, 43 pp. Martins, H.R., 1982. Biological studies of the exploited stock of Loligoforbesi (Mollusca: Cephalopoda) in the Azores. J. Mar. Biol. Assoc. UK, 62: 799-808. Pierce, G.J., Boyle, P.R., Hastie, L.C. and Shanks, A., 1994. Distribution and abundance of the fished population of Loligoforbesi in UK waters: analysis of fishery data. Fish. Res., 21:193-216. Porteiro, EM., 1994. The present status of squid fishery (Loligoforbesi) in the Azores archipelago. Fish. Res., 21: 243-253. Ragonese, S. and Jereb, P., 1986. Loligoforbesi Steenstrup 1856 (Cephalopoda: Loliginidae) nel versante siciliano del Mare Pelagico (Canale di Sicilia): nota preliminare sulla distribuzione, composizione per taglia e biologia riproduttiva. Nova Thalassia, 8 ( 3 ): 529-535. Roper, C.F.M., Sweeney, M.J. and Nauen, C.E., 1984. FAO species catalogue. Vol. 3. Cephalopods of the world. An annotated and illustrated catalogue of species of interest to fisheries. Fish. Synop. 125, Vol. 3, FAO, 277 pp. S~inchez, P., 1985. La P~che de crphalopodes sur la c6te Catalane. Rapp. Comm. Int. Mer Mrdit., 29(8): 233-236. Sfinchez, P. and Guerra, A., 1994. Bathymetric distribution and aspects of the life history of Loligo vulgaris in the Catalan Sea (NW Mediterranean ). Iberus, in press. Sfinchez, P. and Martin, P., 1993. Population dynamics of the exploited cephalopod species of the Catalan Sea (NW Mediterranean). Sci. Mar., 57 (2-3): 153-159.
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Von Boletzky, S. and Mangold, K., 1985. Loligoforbesi in the north-western Mediterranean (Mollusca: Cephalopoda). Rapp. Comm. Int. Met M~dit., 29 (8): 245-246. Worms, J., 1979. Uutilisation des prises commerciales en biologie des p~ches. Application a l'6tude d'un population de Loligo vulgaris (Cephalopoda: Teuthoidea) au Golfe de Lion. Th~se 3emecicle. Universit6 de Montpellier 2, 197 pp. Worms, J., 1983. Loligo vulgaris. In: P.R. Boyle (Editor), Cephalopod Life Cycles. Vol. 1. Species Accounts. Academic Press, London, pp. 143-157.
Fisheries Research 21 (1994) 217-230
The Spanish fishery for Loligo: recent trends A. G u e r r a a'*, P. S~inchez b, F. R o c h a a alnstituto de InvestigacionesMarinas (CSIC), Eduardo Cabello 6, 36208 Vigo, Spain blnstituto de Cienciasdel Mar (CSIC), PaseoJuan de Borbrn s/n, 08039 Barcelona, Spain
Abstract The Spanish fishery for the loliginid squids Loligo vulgaris and Loligo forbesi is described, with particular emphasis on the period 1983-1991. During this period the landings of squid in Spain stayed at a relatively constant level of around 2200 t. The value of the Spanish squid landings increased throughout the 1980s and amounted to £9.7 million in 1991. The two species of squid are not treated separately in the official statistics, and therefore the percentage corresponding to each is unknown; nevertheless, in the maritime regions of the Mediterranean, L. vulgaris is practically the only species landed, while in Atlantic regions, both are landed, although L. vulgaris is more abundant than L. forbesi. Particular attention is paid to the analysis and description of fisheries and squid landings in Galicia (northwest Spain) and Catalonia (northeast Spain), during the period 19801991. In both regions, part of the landings correspond to trawling and purse-seine fisheries targeting finfish, where squid is caught as a by-catch. There are also important seasonal artisanal fisheries where the target species is squid. Landings have shown a marked seasonality; being more plentiful in summer and autumn. This resource does not show signs of overfishing. The present methods of fishing management are discussed, and proposals are put forward to modify some of these in order to avoid catching immature individuals of less than 200 mm mantle length. Keywords:Loligoforbesi; Loligo vulgaris; Spain
1. Introduction The Spanish fishery for loliginid squid comprises mainly of two species: Loligo vulgaris Lamarck, 1798, and Loligoforbesi Steenstrup, 1856. Two other species, Alloteuthis subulata (Lamarck, 1798) and Alloteuthis media (Linnaeus, 1758 ), are also landed in Spain, but in smaller amounts. * Corresponding author. 0165-7836/94/$07.00 © 1994 Elsevier Science B.V. All rights reserved SSDIOI65-7836(94)O2014-Z
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In 1990, neritic squid catches amounted to about 5326 t in the northeast Atlantic, mainly L. forbesi and L. vulgaris, whereas Mediterranean catches reached 10 582 t, mainly ofL. vulgaris (Food and Agriculture Organization (FAO), 1992 ). Loligo vulgaris is widely distributed in the Mediterranean and northeastern Atlantic (Worms, 1983; Guerra, 1992). While it is not an important species among the commercially exploited cephalopods in the world, it can be significant on a local scale (Guerra and P6rez-G~indaras, 1983 ). No major specialised fishery for Loligo vulgaris exists in the northeastern Atlantic, where it is mainly a by-catch of multi-species trawling fisheries, but there is a small artisanal fishery using hand-lines and home-made jigs (Worms, 1983; Guerra et al., 1992; Cunha and Moreno, 1994). In the Mediterranean, although L. vulgaris is not really a target species, it is rather heavily fished by Spain and Italy (Worms, 1983). Market prices for Loligo vulgaris are high, representing 2.05 % of the total turnover for fresh fish sales in Catalonia (northeast Spain) (Martin, 1991 ). In Spain L. vulgaris is highly appreciated and forms a part of the traditional diet of coastal and many inland populations, playing an important role in the local fish markets (Guerra and P6rez-G~lndaras, 1983; Guerra, 1984). Loligoforbesi is a common squid species in the eastern Atlantic and also occurs in the Mediterranean Sea, although its distribution is not fully established (Roper et al., 1984; Guerra, 1992). Loligoforbesi has been observed throughout the Mediterranean (Mangold and Von Boletzky, 1988) being scarce in the northwestern Mediterranean (S~inchez, 1985; Von Boletzky and Mangold, 1985 ), but relatively abundant in the Sicily Channel (Ragonese and Jereb, 1986 ). Loligo forbesi is the only squid species of commercial importance fished in waters of the United Kingdom, where it is landed largely, but not exclusively, as a by-catch from demersal trawl and seine-net whitefish fisheries (Pierce et al., 1994). It is also the only squid species of economic importance in the Azores, where the fishery involves an artisanal fleet equipped with hand-lines and homemade jigs (Martins, 1982; Porteiro, 1994). In Portugal, L. forbesi is caught as a by-catch in the multispecies trawl fisheries, together with L. vulgaris, but a local artisanal fishery also exits, employing hand-jigs (Cunha and Moreno, 1994). On the west African coast, the species is caught as by-catch in the multispecies fisheries in various locations (Burukovski et al., 1979; M.M. Fern~indez, personal communication, 1994). In the Mediterranean this species is mainly caught as a by-catch in the multispecies trawl fisheries. Data on squid fisheries in Spain have not been previously summarised. The broad aims of this analysis are to describe the current status of the Spanish squid fishery with particular emphasis on the period 1980-1991, and on the Galician and Catalonian fisheries. This work constitutes the most comprehensive study of loliginid squids landed in Spain. Information on fishing methods, the economics of squid fishing and trade in squids is presented.
A. Guerra et al. / Fisheries Research 21 (1994) 217-230
219
2. Materials
From January 1989 to January 1992, monthly visits were made to the main fishing ports in Galicia (northwest Spain) and Catalonia (northeast Spain). Owing to the lack of official statistics on squid landings since 1986, during these visits contact was established with the personnel in charge of the fishermen's cooperatives in the ports of these two regions, who provided data on the monthly squid landings and prices from 1980 to 1991, and also fishing boat skippers were interviewed. Data on squid landings in Spain by weight and by value from 1983 to 1986, were obtained from the Maritime Fishing Annual, which, inexplicably, is no longer published. Until 1991, these data, and data on squid landings in each maritime region of Spain (Fig. 1 ) for 1990 and 199 l, was obtained by consulting the files of several private companies at a national level. Although there is information available on the number of vessels, their characteristics and fishing hours, it is not possible to refer to fishing effort for squid, since the fishery is multispecific, and squid is caught as by-catch, the target species being finfish. Unfortunately, Spain does not record landings and fishing effort for single ICES 10° W N!
45 ¢
0°
'
'
|
ATLANTIC OCEAN
CANTABRIc Ribadeo
40 °
-,.
E"
• AMADRID~N S
p
BALEAR
2
Fig. 1. Map showing the maritime fishing areas of Spain.
A. Guerra et aL /Fisheries Research 21 (1994) 217-230
220
statistical rectangles, as occurs in other countries (e.g. United Kingdom; Pierce et al., 1994). All data were transferred to single PC-based spreadsheets, written using QUATRO-PRO V.4.0, which was also used to perform the analyses and to generate graphics.
3. R e s u l t s
The two main species of loliginid squids (L. vulgaris and L. forbesi) of fishery importance are not differentiated in the statistics. Both are sold together in the markets, obtaining similar prices and are marketed in similar ways. For this reason it is impossible to distinguish between the percentages corresponding to each of the species in the statistics. Nevertheless, the Spanish loliginid squid landings comprise mainly ofL. vulgaris, which is the most common species in the Atlantic and the only one present in the Mediterranean in relatively large quantities, but some of these landings are of L. forbesi, mainly those from the Spanish Atlantic coast (Cantabrian, Northwest and South Atlantic maritime regions; Fig. 1 ). Visits to the ports and interviews with fishing boat skippers allowed us to become acquainted with how the artisanal fisheries operate and their importance. These catches are not brought into the fish exchange and are not accounted for in the official statistics, owing to the fact that, in general, they are sold to local bars and restaurants or are consumed by the fishermen themselves. These fisheries use hand jigs and beach seines in Galicia, and hand jigs in Catalonia, where part of the artisanal landings (mostly with trammel nets) are brought into the fish exchange and accounted for in the official statistics. The general trend of Spanish landings, (Fig. 2 ) shows that the landing levels of 10
35O0
9.5 3
9 8.5 •a
~
.7.5
i
.7
15 -~ 1
Landings A VNue
1483 1484 1485 1486 1~7 1488 1~J89 1490 1491 Year
.6.5 6
Fig. 2. Annual squid landings in Spain by weight and value (pounds sterling), from 1983 to 1991. Data only refers to trawling fishery.
A. Guerra et al. / Fisheries Research 21 (1994) 217-230
221
the loliginid squid fishery were relatively constant from 1984 to 1991 (2200 t year-l). The value of Spanish squid landings increased throughout the 1980s from £6.6 million in 1984 to £9.7 million in 1991. This value is very small in comparison with the value for finfish (Fig. 3 (B) ). Table 1 shows the loliginid squid landings for each Spanish maritime region (Fig. 1 ) for 1990 and 1991. The relative importance of landings of fish, crustaceans and cephalopods by weight (A) and value (B) in Spain from 1983 to 1991 is shown in Fig. 3. The percentages represented in both figures are the average values calculated for this period, which were practically constant (4.3-5.6% for weight and 6.3-7.1 for values). Loliginid (long-finned) squid represent 11.2% by weight or 22% by value of CEPHALOPODS (5.(7%)3~
CRUSTAGEAN(S2 ~ l ~ l . ~ SOTI-OM FiSH (313%)
I
Spain
PELAGIC FISH (61.5%)-~" ~
Weight ( 1983-1991)
CEPI CRUSTACE
PELAGIC FISH
Value (1983-1991) Fig. 3. Percentagesof Spanish landings for all species offish, crustaceansand cephalopods by weight (A) and by value ( B ) for the period 1983-1991. The percentageshown is the averagevalue calculated for said period. Table 1
Squid landings (amount in tonnes and as a percentage of total landings) in each Spanish maritime region for 1990-1991 Maritime Region
1990
Tonnes Cantabric
Northwest South Atlantic South Mediterranean Levante Tramontana (Catalonia) Balear
Total
165.8 461.3 569.8 291.3 348.2 250.7 49.1 2136.2
1991
Percentage 7.8 21.7 26.8 13.7 16.2 11.5 2.3
Tonnes 270.2 428.6 538.2 325.6 363.2 237.0 62.0 2214.9
Percentage 12.2 18.9 24.3 14.7 16.4 10.7 2.8
222
A. Guerra et al. /Fisheries Research 21 (1994) 217-230
Spanish landings of cephalopods (Fig. 4). These percentages are average values calculated for the period 1983-1991, during which the importance of loliginids was practically constant. Annual landings of squid caught in Galician trawling fisheries for the period 1980-1991 (Fig. 5) ranged from 218 t in 1988 to 550 t in 1980 and 1982. The total annual value of the catch peaked in 1986. Landings in the north area of Galicia (from Ribadeo to Finisterre; Fig. 1 ) represented about 50% of the total in Galicia from 1980 to 1986, but have experienced a dramatic decrease since 1987 (Fig. 5 (B)), while the landings from the south area (from Finisterre to La Guardia; Fig. 1 ) came to represent about 95% to the total landings from 1987 to 1991. From 1986 to 1991, the trawl squid landings in Galicia showed a marked seasonality. Landings were low during spring and summer, while there was an increase in autumn and winter (Fig. 6 ). In the trawling fisheries of Galicia both L. vulgaris and L. forbesi are taken together as by-catch of finfish. They are present in the fishery throughout the year from 100 to 350 m depth. L. forbesi is more abundant than L. vulgaris in the north fishing grounds, while in the south, the opposite occurs. A small scale directed hand-jig fishery takes place in inshore waters ( 10-60 m depth) of the Galician coast. This is a seasonal fishery, which extends mainly from May to September. This fishery is carried out by a numerous and mixed artisanal fleet, comprising about 1000 open boats, from 3 to 10 m in length, and only equipped with hand lines and home-made jigs. Fishing operations take place in daytime. Fishermen jig for squid only when the animals are found in relative abundance and when the weather permits. The crew comprises one or two fishermen, generally retired from other fishings. Most of the catches are of small, immature squids, and large immature individuals. These catches arc not regis-
SHORT FINNEDSQU[
JNEDSQUID(11,2%) CUTI]~FISH (13.5%)
OCTOt~USES
Weight
SHORT F {22.0%)
4%)
OCTOPUSES V;~lU~
Fig. 4. Percentage of Spanish landings for each type of cephalopods by weight (A) and value (B) for the period 1983-1991.
A. Guerra et al. / Fisheries Research 21 (1994) 217-230
i'lttilj 80
81
82
83
84
B5
86
87
88
89
90
223
gl
141~00
8
C: 81
82
350.
~0. 250.
83
84
85
SouthArea
8 4'50"
50. O;
Io
I~JI 80
.
86
87
88
89
gO 91
~ ~~
LRib
80 81
.
. . . . . . . . . 82 83 84 85 86 B7 88 89 Year
IBm L oQs
go
91
180000
.leOOoo ,1~ ,~ooo ~ 40000
20000 0
J
Fig. 5~ Annual squid landings in Galicia by weight (t) and by value (thousands of pesetas) during 1980-1991. A, totals; B, north area; C, south area.
tered in the official statistics of landings. Generally, in the north, the small, immatt~re squid are L. vulgaris and the large immature individuals are L. forbesi, while in the south, only L. vulgaris is caught. They are sold directly to local bars and restaurants, or consumed by the fishermen. It is very difficult to estimate the amount represented by this seasonal fishery, but from our observations, it is 7090 t per month. Galicia also has another artisanal fishery which takes place inside the south rias
224
A, Guerra et al. /Fisheries Research 21 (1994) 217-230 100
!iD :
11
il 88
89 Year
90
1991
Fig. 6. Total monthly squid landings in Galicia duringthe period 1986-1991 (O, October; N, November; D, December). 700
3
600
"2.5
500 •~
-2
c
400 -1.5 ~
~ 300 200
-1 Landings ~
100 ~78' 1~80' 1~82' 1 9 ~ ' 1 ~
£ Million
' 1~88' 1 ~ 0 ' 1~, o.s
Year Fig. 7. Annual landings in Catalonia by weight and value (pounds sterling) from 1980 to 1991.
(from 3 to 40 m depth). This is a seasonal fishery which extends mainly from July to November. This artisanal fishery is operated by an artisanal fleet equipped with beach seine nets. It is a multispecies fishery where juveniles of several finfish species are caught. The catches also include immature Loligo vulgaris and immature and adult Alloteuthis subulata, which are the only two loliginid species that live and spawn inside the rias (Guerra, 1984). Squid caught with this type of fishing gear are of 50-150 mm mantle length (ML). These catches are not registered in the official statistics of landings. The catch is very variable from day to day, thus making it difficult to estimate the amount represented by this seasonal fishery, but from our observations, it varies from 5 to 10 t per month. The price of the squid from the Galician trawling fishery ranged from 530 to 873 pesetas kg-1 for the period 1983-1991, while the price of the squid from jig and beach seine fisheries ranged from 850 to 1600 pesetas kg- 1 for the same pe-
A. Guerra et al. / Fisheries Research 21 (1994) 217-230
N
0
225
Io o, o
&
"10
.¢_
._>,
8
50-
4030. 20. 10. 0
.................................................................................... ! L 1981 82 83 84 85 86 87 88
89
................... 90 91
Year
Fig. 8. Monthly landings ofLoligo vulgaris in Catalonia during the period 1981-1991 (O, October; N, November; D, December).
i
Trawl
~2 O.8 07t ~o,1
0.4 I
0.35~
Seine
~025~' 02~ O.lS-
Fig. 9. Monthly evolution of Loligo vulgaris landings in the port of Blanes (Catalonia) during the period 1986-1990 on three types of fishing.
226
A. Guerra et al. /Fisheries Research 21 (1994) 217-230
riod. This difference is due to two reasons: the superior quality of squid from jig fisheries, since it is landed fresh, whole and not skinned, and small squid being more highly regarded than large squid. In Spain, loliginid squids are used exclusively for human consumption. They are highly regarded in local and national markets. Annual landings of Loligo vulgaris in Catalonia (northeast Spain, from the French border to the River Ebro; Fig. 1 ) during 1980-1991 ranged from 624 t in 1980 to 200 t in 1990, while the price of the squid ranged from 350 to 1525 pesetas kg-~ for this period (Fig. 7). Monthly landings ofL. uulgarisin Catalonia during 198 I- 1991 (Fig. 8 ) showed a marked seasonality. Landings were much more abundant in summer and autumn than in winter and spring. The largest catch was generally obtained in October (50 t). Exceptionally, in August 1988, the catch was 92 t. During the past few years, the squid catch in spring has been almost non-existent. In the Catalonian statistics shown in Figs. 7 and 8, landings from all types of fishing gear are included. At the port of Blanes (Catalonia), three types of fishing gear are involved in this fishery. Trawls caught 85.9% of the squid, purse-seine nets 4.2%, while artisanal fleet (trammel nets) caught 9.9% where L. oulgaris is caught as a by-catch. The seasonal pattern of landings is very similar for all years (Fig. 9 ).
4. Discussion
According to our study and results obtained by Worms (1979) and Sgmchez and Martin (1993 ), it seems that Atlantic and Mediterranean Spanish stocks of Loligo vulgaris and L. forbesi are not likely to become a target species for a highly specialised fishery. The stability of the Spanish landings from 1983 to 1991 seems to indicate that the stocks are not over-exploited. Although the demand for loliginid squid in the Spanish market has been on the increase in recent years, it has been supported by other species, such as Loligo gahi from the Falkland Islands, Loligo pealei from the USA fishing grounds, Loligo opalescens from California, and Loligo duvauceli from the Indian Ocean, either caught by Spanish fleets or imported. As this loliginid squid is brought onto the Spanish market frozen, and local squid is marketed fresh, there is no competition between the products. The Spanish market is very strict: thawed squid is generally detected and sold as fresh only with difficulty. It may be thought that the dramatic decrease in loliginid squid landings in the north of Galicia from 1987 to 1991 (Fig. 5 ) was due to overflshing, but it is very difficult to demonstrate this since squid, in this fishery, is caught as by-catch of trawlers catching finfish. The apparent discrepancy between the seasonal pattern of squid landings in Catalonia and Galicia is misleading. Squid landings appear lower in spring and summer in Galicia (Fig. 6) since these statistics exclude the 90-130 t per month from the artisanal fishery. If this figure were included, spring and summer would
A. Guerra et al. /Fisheries Research 21 (1994) 217-230
227
have the greatest landings, as occurs in the Mediterranean (Fig. 7 ), statistics for which do include landings from the artisanal fishery. The seasonality shown by the squid landings in Galicia and Catalonia, with a greater abundance in summer and autumn, coincides with observations made by Pierce et al. (1994) in Scotland, and by Cunha and Moreno (1994) in Portugal. As indicated by Pierce et al. (1994), the seasonal pattern in landings (being unrelated to total fishing effort) may be regarded as indicating fluctuations in abundance. Young squid recruit to the fished population largely in the summer (JulySeptember). Peak spawning occurs between December and February in L. forbesi, whilst in L. vulgaris it peaks between December to April, but continues throughout the year (Guerra and Rocha, 1994). Thus the rising catches in the latter half of the year are maturing, pre-breeding squid and catches fall off prior the peak of the breeding season. As in Scotland (Pierce et al., 1994), in Galician and Catalonian waters it is unclear whether the seasonal decline in catches is a direct consequence of fishing or whether natural mortality or reduced catchability is responsible. Reduced catchability might occur due to horizontal or vertical movements into unfished waters (Guerra and Rocha, 1994; S~inchez and Guerra, 1994). Spawning areas of L. vulgaris and L. forbesi are not well known although egg masses are recovered from creel lines in Scotland (Lum-Kong et al., 1992), Algarve, south Portugal (Coelho et al., 1994) and Galicia (Guerra and Rocha, 1994) and breeding squid are caught in inshore waters. In the artisanal fisheries using beach seine nets, small, immature individuals of L. vulgaris (50-150 mm ML) are caught, which serves to indicate that recruitment of the species occurs mainly during summer and autumn. This agrees with biological data obtained by Guerra and Rocha (1994). In some of the Autonomous Communities in Spain (e.g. Galicia), there is a minimum legal size for squid landings of 100 mm ML. In accordance with the size at maturity of both species now established (Guerra and Rocha, 1994), it would be appropriate to increase the legal size to 200 mm ML. In recognition of the spawning season and the growth rates of both species (Guerra and Rocha, 1994), it may also be appropriate to establish a closed season for both species, at least from 1 December to 1 March. However, these measures could not easily be introduced, owing to social repercussions arising from the restriction of fishing effort. The measures currently in force on the Spanish coasts regarding trawling fisheries, which forbid trawling between the coast and 100 m depth in the Atlantic and!between the coast and 50 m depth in the Mediterranean, appear to be sufficient to prevent overfishing on squid. This fishery is directed at a number of species, and it is very difficult to adopt suitable fishing management measures for multispecific fisheries where squid is caught as a by-catch (Anonymous, 1993 ). The question of whether the squid Loligo vulgaris reynaudii resource in South African waters can be managed effectively was examined by Augustyn et al. ( 1992 ) in the light of developments in the fishery and knowledge of the resource gathered in recent years. These authors show that, although much more is known
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than few years ago, many questions relating to the resource are still unsolved, as is currently the case with the L. vulgaris and L. forbesi resources in Spanish waters. To date, management of the resource in South Africa as well as in Spain has been conservative, and this can be justified in the case of short-lived species such as squids because there are no buffering effect of several age-classes and a stock collapse in any single year will have immediate and serious consequences (Augustyn et al., 1992 ). It has been geared to such rational or 'common-sense' measures as size restrictions, as well as a closed area for trawling from coastal line to 50 or 100 m depth. Although it cannot be claimed that these management measures have been solely responsible for the relative stability of the stocks, they have contributed to it. However, these long-term measures, all appropriate in the early stage of a fishery when knowledge is limited, should be replaced by more flexible alternatives as knowledge improves, as indicated by Augustyn et al. ( 1992 ). Short-term mechanisms may be applied. According to Augustyn et al. (1992) this implies that: (i) stock levels must be measured more frequently and accurately in future; (ii) the stock-recruitment relationships must be well known; (iii) although more is known about longevity, fecundity and other aspects of the squid life cycle, the effect of fishing activity on spawning squid and the effects of environmental changes must be examined. In the meantime, the management measure already enforced and perhaps effort control in the artisanal fisheries appears to be the best approach for management, although a more rational management procedure should be introduced to ensure that the decisions made are structured ones. One such approach is offered by the Leslie-Delury analysis (Beddington et al., 1990; Augustyn et al., 1993), which could be introduced as a way of managing effort and preventing overexploitation. Caveats are that the practical problem of real-time data input (catches) must be overcome, as indicated by Augustyn et al. (1992). In order to apply this solution in the Galician squid fishery a network of sampling has been organised to obtain accurate monthly catches.
Acknowledgements We would like to thank M. Rasero, A.F. Gonz~llez, M.T. Fern~indez, F. Casas and J. Alen for his efficient technical assistance and useful suggestions, and the people responsible for the Fishermen's Cooperatives and companies who helped us in obtaining information. This work was funded by the Commission of the European Communities within the frame of this EEC research programme in the fisheries sector (FAR, contract no. MA. 1.146 ).
References Anonymous, 1993. Report of the Study Group on Cephalopod Biology, Kiel, 21-22 September 1992, ICES C.M. 1993/K:66. Augustyn, C.J., Lipinski, M.R. and Sauer, W.H.H., 1992. Can the Loligo squid fishery be managed
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