EASTERN CENTRAL ATLANTIC - ATLANTICO CENTRO-ORIENTAL (Continued)

The stock suffered a significant reduction in 1977. Following higher recruitment 1980 and 1981, biomass rose in 1981 to a level almost equivalent to that in 1976 dance in numbers of fish being much greater. High recruitment in recent years has brought a about a significant rejuvenation of the stock. An increase in exploitable biomass may be expected.

With regard to upwelling indices, the only available series is that provided by Bakun He calculated a monthly upwelling index from 1946 to 1981 for 28 degree N,13 degree W. This Is near cape Juby, which is in the southern part of zone B. This index was obtained by calculating the winds produced by atmospheric pressure fields and by corresponding Ekman transport. Details of the method of calculation and its limitations are given in Bakun (1973). From this monthly index, an index of mean annual upwelling from 1946 to 1981 was calculated (Figure 15). These annual values and their deviations from the overall mean for the period are given in Appendix V. From 1946 to 1959, they are below the mean, with the exception of 1954. Since 1970, values have all been above the mean. It appear, then, that the upwelling in this zone has an opposite tendency with respect to the northen zone upwelling. This conclusion must be considered with prudence because Bakun (pers. comm., 1973) has emphasized that these calculations may be bad indicators of long-term variations, since the system of atmospheric pressure data collection has changed with time. They may be more useful for short-term intra-and inter-annual comparisons.

Results and discussion. If we make the hypothesis that fluctuations in upwelling Bring about parallel variations in population abundance by means of recruitment, effects On biomass would require a certain time lag. Catches may serve as an index of abundance in fishing effort remains more or less stable during a period of many years. As the sardine catch in zone B is composed mainly of fish of one, two and three years old, annual catches should be compared with the average upwelling index of the preceding three years. Data are shown in Table 5, and the graphical representation in Figure 16.

Figure N^o 15: Mean annual upwelling index from 1946 to 1981 for 28°N by 13°W in tons/s per 100 m width, calculated from the monthly data of Bakun.

Figure N^o 16: Catches of sardines in zone B (thousands of tons) as a funcion of the average of the upwelling indices for the preceding three years (tons/s per 100 m width).

A functional linear regression using the twelve pairs of data gives a high correlation coeffcient of r = +0.930. A regression using logarithmic values results in a slightly higher correlation coefficient of r = +0.953. These are both significant at the 99% level. The linear regression is expressed by:

C = 1.717 U.I. - 230,

and the curvilinear regression passing through the origin is given by:

C = 2.7 x lO^-7. U.I. 3-747.

At first sight, we might consider the hypothesis to be realistic and that catch is strongly linked (90% of the variance is explained) with the average upwelling of the preceding three years. It is fitting in the meantime to be skeptical of this relationship. For one, the series of observations is very short and the change in values consists only Of the maximum between two minima. For another, if this relation shows that strong upwelling brings about higher recruitment, we should see an agreement between values of the upwelling index and recruitment. The strong recruitments of 1980 and 1981 coincide with the highest values of the upwelling index, but this is not the case for 1978.

In order to estimate recruitment prior to 1976, recruitment obtained by cohort analysis was compared to catches of age 0 and age 1 sardines, available since 1968 Belvéze 1972, 1981). Catches of age 0 sardine in numbers of fish, were added to cathes of age 1 of the following year because in certain years, age 0 fish were incom- pletely recruited to the fishery.

The results are presented In Table 6 and in Figure 17. There is an evident parallelism between recruitment and catches of ages 0 and 1 in zone A. If the hypothesis that this parallelism existed before 1976 is made, the Moroccan catch of young sardines may be taken as a proportional index of recruitment.

A very important recruitment took place in 1970 while the upwelling index was slightly lower than the mean. However, from 1973 to 1975, the upwelling index remained at high values, without an increase in recruitment.

This contradiction with the preceding results imposes doubts on their validity. It is possible that the observed relation between catch and mean upwelling of the three preceding years may, in reality, only be a coincidence between two series that are too short. It is equally possible that an increase in upwelling south of zone B may attract the sardines from zone C. This hypothesis is not easily verifiable but should not be discarded a priori because the period of greatest catches in zone B corresponds to a period of weakening of the upwelling in zone C.

Zone C

This zone, situated between 20°N and 26°N harbors a sardine population which is relatively independent of zones A and B. The zone has increased in area by the extension southward at the start of the 70's. Exploitation began in 1968, the by-catch consisting of mackerel and horse-mackerel. Catches increased considerably in several years with greater mobility and power of the exploiting fleets. In 1973, the sardine became the principal catch species of the fishery.

Available data. For abundance, catches are known by the declarations of fishing nations to CECAF, and are published in its statistical bulletin. Abundance in numbers biomass in weight, obtained by cohort analysis, from 1972 to 1979 were presented at the Ad hoc Working Group on the Sardine by Domanevsky (Dakar 1980). Three estimates of biomass were made by acoustic surveys (Bazigos et aL, 1980; Lamboeuf et al, 1982). These different data are presented in Table 7.

With regard to indices of upwelling, variations in upwelling were analyzed by Sedykh 1978, 1979). Ekman transport values were calculated for squares of 5 degrees for the period 1957 to 1977. A considerable increase in the intensity of upwelling was found for the years 1971-1974, followed by a decrease in 1975-1976, and a new increase in 1997. It was estimated that the cycle of abnormally strong upwelling finished in 1978.

Figure N^o 17: Recruitment, calculated by cohort analysis, from 1976 to 1981 and catches of Age 0 sardines added to catches of Age 1 the following year in zone A from 1968 to 1980.

Anomalies of sea surface temperatures (SST) recorded by merchant ships alonq the 1enght Of the northwest African coast were provided on a monthly basis for the period 1971-1981 By McLain. The usual maritime route skirts the African coast to the south of the Canary Islands, and the number of observations is highest between 27°N and 20°N (zone C). observations are least frequent or even absent north of Cape Bojador (zones A and B). Sea surface temperature anomalies are averaged monthly for each one degree square.

Results and discussion. An annual mean was determined, weighted by the number of at each month, on the basis of the monthly data provided by McLain. These means, from 1971 to 1981, are given in Table 8, for each one degree square for zone C. The overa11 mean is also given.

Variations in the annual means of SST anomalies, represented graphically in Figure Show, that negative anomalies were more important in the southern part of the zone Than in the northern part from 1972-1974. This agrees with the observations of Sedvkh and explains the extension and the development of the sardine population between 22°N 20°N through the years 1971-1974. The strengthening of the upwelling pointed out by Sedykh also causes more important cooling of the surface waters in the southern part of the zone. Mean annual SST anomalies become strongly positive starting in 1978, which is also in accordance with Sedykh's estimate concerning the end of the period of abnormally high upwelling. Generally, the amplitudes of the variations are greater in the south than in the north.

The comparison between the upwelling indices, stock biomass and catches shows the concordance between the values of upwelling calculated by Sedykh (Ekman transport in tons second per 100 m width) and the annual mean SST for the whole zone. Stock biomass increases with increasing upwelling intensity with a time lag of a year. This is expected hypothesis that upwelling acts on recruitment is correct. Catches continued to increase up to 1976 when biomass was already declining due to concentration of fishing effort industrial fishing vessels which were attracted by high yields recorded in previous years, and were not allowed in other areas by the extension of Exclusive Economic zones. In 1977 and 1978, catches represented a bit more than 30% of the biomass, which is a level of exploitation comparable to that of zones A and B. Starting from 1979, the explotation rate fell to less than 20% following the closure of fishing to the north of the 24th parallel by Morocco. Nevertheless, biomass, estimated by acoustic survey, continued to decrease up till 1981. It appears that environmental conditions are the principal causes of the considerable fluctuations in sardine abundance recorded in zone. T he past six years. The level of exploitation probably accelerated the natural decline of the population, but it cannot be entirely responsible for such a change. The weakening of the upwelling starting from 1976 in the southern part of zone C, may equal have contributed to a displacement of the sardines towards the north, where the weakening was less pronounced. The acoustic surveys of 1979 to 1981 proved a gradual disappearance of sardines between 20°N and 23°N (Bazigos et aL, 1980; Lamboeuf et al., 1982). It is difficult to determine whether this disappearance is linked to the concentration of effort to the south of 24°N, or to a real displacement of the sardines caused by the weakening in upwelling, as fishing is no longer authorized north of 24°N since 1979.

CONCLUSIONS

There are two main populations of sardine (Sardina pilchardus Walbaum) along the Northwest African coastline in areas of the continental shelf where the littoral waters Are enriched by upwelling of deep water (Central North Atlantic Water of the Canary current). The boundary between this watermass and the Central South Atlantic Water is at the level of 20°-22°N and corresponds approximately to the boundary between the sardine and the sardinellas {Sardinella aurita and S. eba). The sardines of the north zone are the object of two separate fisheries. Fishery A, the oldest, has been tradi- tionally exploited by artisanal Moroccan seiners. Fishery B is exploited by boats based largely in the Canary Islands. The population retreats to zone B in winter, when the greatest amount of spawning takes place, and spreads out in summer, invading zone A. The Moroccan fishing is seasonal and is subject to fluctuations in availability of the sardine because the boats, which have only a limited sphere of action, cannot follow the sardine population in its migration. The migration from north to south is controlled by the amount of primary production between 30-°N and 32°N in summer. This productivity depends on the force of the trade winds, which generate upwelling and also short-term variations in wind speed. The periods of greatest productivity occur while the winds weaken after a time of strong winds. Despite the occurrence every seven or eight years of greatly increased availability corresponding to a serious drought on the coast, the general tendency has been for a gradual weakening in the force of the trade winds, especially since 1975. To a large extent, this has been the cause of the decline of the Safi-Essaouira fishery. While the sardine remains the dominant species, it is no longer the exclusive species. With the weakening of the trade winds, the anchovy, the horse-mackerel and especially the mackerel, have been making up a bigger part of the catch. In zone B, the effect of upwelling on abundance has not been clearly shown, and there may be a mixing with the southern population between 28°N and 27°N. There is also no evidence of the relation between upwelling and availability, but in this fishery, the boats are apt to follow the sardine population along its migration. The southern population (fishery C), is found in an area of nearly year-round upwelling. It is characterized by extreme variations in abundance as well as in area occupied by the stock. Variations are well correlated with fluctuations in upwelling intensity. Since 1978, the upwelling has been weakening, and the stock has diminished considerably. Nevertheless, it seems that the high level reached in 1974, was due to abnormally strong upwelling during the preceding years, and therefore, does not represent the average size of the population.

(a) Cohort analysis
(b) Acoustic survey

Figure N^o 18: Changes in mean annual sea surface temperature anomalies for each square of 1 degree and for the whole of area C, calculated for 1971 to 1981 from data of M cLain.

Figure N^o 19: Comparison of catches, biomass calculated by cohort analysis and by acoustic survey, of upwelling index (from Sedykh 1979) amd mean annual sea surface temperature anomalies after the data McLain for area C

Population studies of the sardine along the northwest African coast are recent, and the series of annual data are very short and often inadequate. It is, therefore, difficult to predict the change to come. However, if the empirical relations prove correct and the observed tendencies persist, a geographical concentration of the stocks between 24°N and 30°N, and declines of the fisheries situated at the margins of these limits, are to be expected.

This decline has important socio-economic consequences for Morocco. The principal canneries are situated at Safi and Essaouira, where numerous workers are employed. The limited sphere of action of the Moroccan sardine boats, which do not have means of on-board preservation and are small in size, means that they cannot follow the sardine migration. They are restricted to the sardines which enter their fishing area. As less and less sardines are coming in, it is necessary to take the fishing to where the fish are, i.e. zone B. There are two options open. One is to have bigger boats with refrigeration or freezing capabilities in order to bring back the fish caught south of Agadir to Safi. This would require restructuring of the fleet, and technical training of crews. The other option is to base a sizeable part of the present fleet in the new port of Tantan, at the center of zone B, and to send the catch by land to the canneries of Safi. This would require the creation of a fleet of refrigerated trucks.

Both solutions would bring about an increase in the cost price of the raw material, which would cancel the rentability of the production of preserved sardines. Productivity must also be improved by modernizing and regrouping the factories, which are too small and too numerous. This modernization scheme by regroupment and automation cannot be accomplished without a major reduction in manual labor. This would pose grave social problems for the cities of Safi and Essaouira, where the canning industry is the major means of employment.

It may be that the solution for the future is a gradual transfer of the factories to Tantan. This solution may be economically satisfactory, but would bring about the end of the fishing industry of Safi and Essaouira.

ACKNOWLEDGEMENTS

We would particularly like to thank Dr. Andrew Bakun and Dr. Douglas McLain for kindly providing us with the results of their evaluations of the upwelling and sea surface anomalies along the northwest African coast, and also for their pertinent advice. We thank Bruno Richebè for his invaluable contribution, and Dr. Richard Parrish, whose advice guided our study during his visit to Morocco.

Values between parentheses were estimated from data recorded at Agadir.

overall (general) mean : 160.9

REFERENCES

Allain, C. 1970a. Les conditions hydrologiques sur la bordure atlantique de l'Afrique du Nord-Ouest, Rapp.P.-v.Réun.Cons.Int.Explor.Mer, 159:25-29.

Allain, C 1970b. Observations hydrologiques sur le talus du banc d'Arguin en décembre 1962 (compagne de la "Thalassa" du 2 Novembre au 21 Décember 1962), Rapp.P.-v.Réun.Cons.int. Explor. Mer, 159:86-89.

Andreu, B. 1969. Las branchispinas en la caracterizacion de las poblaciones de Sardina pilchardus Inv.Pesq.Barc.33(2):425-607.

Anon. 1978. Rapport du Groupe de Travail "ad-hoc" sur la sardine (Sardina pilchardus Walb.) COPACE/PACE SERIES/78/7.

Anon. 1980. Rapport de la deuxième réunion du Groupe de Travail sur la sardine (Sardina pilchardus Walb.) COPACE/PACE SERIES/79/15.

Anon. 1981. Rapports des groupes de travail sur les merlus, les céphalopodes, les sardines, les poissons pélagiques côtiers, les poissons demersaux côtiers et les Balistes. In Rapport de la cinquième session du Groupe de Travail de l'Evaluation des Ressources. FID/R 244:21-115, FAO, Rome.

Bakun, A. 1973. Coastal Upwelling Indices, West Coast of North America, 1946-71, NOAA Technical Report NMFS SSRF-671.

Bakun, A. and R.H. Parrish. 1980. Environmental inputs to fishery population models for eastern boundary currents regions, in IOC Workshop Report No. 28:67-104.

Barkova, N.A. 1976. Some peculiarities of sardine (Sardina pilchardus Walb.) distribution and spawning along the Northwest African Coast, ICES 1976/1:6.

Barton, E.D. 1982. Medium scale water mass structure near Cape Corveiro, Northwest Africa, in March 1974, Rapp.P.-v. Réun.Cons.int.Explor.Mer, 180:65-72.

Bazigos, G.P., S. Bencherifi, J. Burczynski, R. Coppola, M. Lamboeuf et M. Rami. 1980. La biomasse de la sardine marocaine en 1979 (résultats préliminaires de prospections acoustiques effectuées en Mai et Novembre 1979), Trav. Doc. Dèv. Pêche Maroc (27):28 p

Belvèze, H. 1971. Premières observations sur le stock sardinier de l'Atlantique marocain, Bull.Inst. Pêches Marit., Casablanca(18):3-35.

Belvèze, H. 1972. Observations complémentaires sur le stock sardinier de l'Atlantique marocain, de 1968 à 1971 et essais d'estimation de quelques paramètres. Bull. Inst.Pêches Marit., Casablanca (20):5-55.

Belvèze, H. 1974. L'etat des stocks de la sardine marocaine à la fin de l'année 1973, Trav.Doc. Dev.Pêche Maroc(6): 17p.

Belvèze, H. 1975. Pluviomètrie et pêche de la sardine au Marco depuis 1936,mise en évidence de cycles parallèles. Trav. Doc. Dèv. Pêche Maroc (10):8p.

Belvèze, H. 1981. Note sur l'état de la pêcherie sardinière marocaine dans l'Atlantique en 1980. Trav.Doc.Dev.pêche Maroc (31):25p.

Belvèrz, H. et J.Bravo de Laguna. 1980. Les ressources halieutiques de l'Atlantiqe Centre-Est Deuxième partie: Les ressources de la côte Ouest-Aricaine entre 24° N et le Detroit de Gibraltar, FAO Doc. Tech. Pêches (186.2): 64p

Belvèze, H.et M. Rami. 1978. Détermination de l'âge de la sardine marocaine (Sardina pilchardus Walb.) Eléments de crossance comparés,Bull Inst. Pêches Marit., Casablanca(23):57-81.

Biaz, R. 1978. Mise au point d'une méthode d'identfication des populations de sardines par électrophorèse des protéines solubles du cristallin. Bull.Inst.Pêche Marit., Casablanca (23):3-55.

Bdhnecke, G. 1936. Temperatur, Salzgehalt und Dichte an der Oberflache des Atlantischen Ozeans. Wiss. Erqebn. Dtsch. Atlant.Exped. "Meteor" 1925-1927. 5.Atlas.

Bravo de Laguna, J., M.A.R. Fernandez and J.C. Santana. 1976. The Spanish fishery on sardine (Sardina pilchardus Walb.) off West Africa ,ICES CM 1976/3:13.

Cadenat, J. et R. Moal. 1955. Note sur la sardine (Sardina pilchardus) dans la région du Cap Blanc. Rapp.P.-v.Réun. Cons. int. Explor. Mer, 137:21-23.

Calvet, C. et Y. Le Goff. 1977. Regimes pluviométriques au Maroc. Note d'information technique No. 6 Service Meteorologie Nationale Imp. Météo. Nle.CASA.

Codispoti, L.A., R.C. Dugdale and H.J. Minas. 1982. A comparison of the nutrients regimes off Northwest Africa, Peru and Baja California. Rapp.P.-v.Réun.Cons.int.Explor.Mer 180:184-201.

Defant, A. 1936. Schichtung und zirkulation des Atlantischen Ozeans. Die Troposphäre. Wiss. Ergebn. Dtsch.Atlant.Exped."Meteor" 1925-27, 6:289-411.

Delgado, A., J. Bravo de Laguna y M.A.R. Fernandez. 1979. Estimación de la abundancia de Sardina pilchardus Walb. de la zona de pesca B de Africa occidental durante 1978. In Rapport de la deuxième réunion du groupe de travail sur la sardine Sardina pilchardus Walb. COPACE/PACE/series 79/15, ann.6:71-85.

Delgado, A. y M.A.R. Fernandez. 1982. Datos sobre la pesquería de (Sardina pilchardus) en la zone de pesca B de Africa Occidental de 1980. In Rapport de la sixième session du Groupe de Travail de l'Evaluation des Ressources -Dakar 1982.

Delgado, A., M.A.R. Fernandez y R. Goni. 1980. Contribucion al estudio de la sardina (Sardina pilchardus Walb.) en aguas de Africa Occidental: III Estudio del crecimento por lectura directa de otolitos y por retrocalculo mediante escalimetria de escamas. Bol.inst.Espa.Oceano. (VI)313.

Domanevsky, L.N. et N.A. Barkova. 1979. Caractéristiques de la répartition et l'état des stocks de la sardine (Sardina pilchardus) au large de l'Afrique Nord Occidentale. COPACE/PACE/series/78/10:86-91.

Domanevsky, L.N. et N.A. Barkova. 1981. Etat du stock de sardine Sardina pilchardus Walb. Clupeiforme, clupeidae, dans la région de l'Afrique du Nord-Ouest. In contributions soviétiques à l'évaluation des ressources halieutiques dans la région du COPACE. COPACE/Tech/81/31:19-30.

Fedoseev, A. 1970. Geostrophic circulation of surface waters on the shelf of Northwest Africa, Rapp.P.-v. Réun. Cons. perm. int. Explor. Mer. 159:32-37.

Fernandez, M.A.R., A. Delgado, A. y J. Bravo de Laguna. 1978. Contribución al estudio de la sardina (Sardina pilchardus Walb.) en aguas de Africa Occidental. II Estimación de la abundancia de la población explotada por la flota espanola. Bol.Inst.Espa.Oceano. (IV) 260.

Fernandez, M.A.R., A. Delgado, A. y J. Bravo de Laguna. 1978. Contribución al estudio de la sardina (Sardina pilchardus Walb.) en aguas de Africa Occidental. I Relación entre la talla, la edad y el número de branquispinas. Bol.Inst.Espa.Oczano. (IV) 259.

Fiuza, A.F.G. and D. Halpern. 1982. Hydrographic observations of the Canary Current between 21°N and 25°N in March/April 1974. Rapp.P.-v.Réun.Cons.int.Explor.Mer, 180:58-64.

Fraga, E. 1973. Oceanografía química de la región de afloramiento del Noroeste de Africa.I. Res. Exp. Cient. B/O Cornide 2:13-52.

Fraga, E. 1974. Distribution des masses d'eau l'upwelling de Mauritanie. Tethys 6(1-2):5-10.

Fraga, E. et M. Manriquez. 1974. Hidrografía de la region de afloramiento del Noroeste de Africa. Datos básicos de la campana "Atlor II" del "Cornide de Saavedra". Res. Exp.Cient. B/O Cornide 3:67-87.

Freon, P. et B. Stéquert. 1979. Note sur la présence de Sardina pilchardus Walb. au Senegal: étude de la biométrie et interpretation. Cybium 3e serie 1979 (6):65-90.

Furnestin,J. 1950. Premières observations sur la biologie de la sardine marocaine, Sardina pilchardus Walb. Memoire No. 14 de l'Office de Pêches Maritimes, série spéciale: Biologie des Clupeidés.

Furnestin,J. 1950. Etude comparative de quelques caractères métriques des sardines du Golfe de Gascogne et du Maroc. Mémoire No. 14 de l'Office des Pêches Maritimes, série spéciale:Biologie des Clupeidés.

Furnestin,J. 1950. Les races de sardines du Détroit de Gibraltar et de ses abords. Rapp.P.-v. Réun. Cons.int.Explor.Mer. 126:62-67.

Furnestin,J. 1955. Remarques sur quelques caractères de la sardine de Mauritanie. Rapp.P.-v. Réun. Cons. int. Explor. Mer, 137:24-25.

Furnestin,J. 1959. L'hydrologie du Maroc Atlantique de 1949 à 1953. Rev.Trav.Inst. Scient. Techn.Pêche Mar, 23(1)5-77.

Furnestin, J. et M.L. Furnestin. 1959. La reproduction de la sardine et de l'anchois des côtes atlantiques du Maroc. Rev.Trav.Inst.Scient.Techn.Pêche Mar. 23(1):79-104.

Furnestin,J. 1970. La sardine marocaine et sa pêche. Migrations trophiques et génétiques en relation avec l'hydrologie et le plancton. Rapp. P.-v.Réun. Cons. int. Explor. Mer, 159:165-175.

Furnestin, M.L.1955. La ponte de la sardine et de l'anchois dans les eaux marocaines au cours des années 1951 et 1952. Rapp.P.-v.Réun. Cons.int.Explor.Mer,137(8):26-28.

Furnestin, M.L. 1957. Chaetognathes et zooplancton du secteur atlantique marocain. Rev. Trav. Inst. Pêche Mar. 21:(1-2) 356 p.

Furnestin, M.L. 1970. Rapport sur le plancton. Rapp.p.-v.Réun.Cons.int.Explor.Mer 159:90-110,

Grall, J.R., P. Laborde, P. Le Corre, J. Neveux, P. Treguer et A. Thiriot. 1974. Caractéristiques trophiques et production planctonique dans la région sud de l'Atlantique marocain - CINECA-CHARCOT I et III. Tethys 6(1-2):11-28.

Grall, J.R., P. Le Corre et P. Treguer. 1982. Short term variability of primary production in coastal upwelling off Morocco. Rapp.P.-v.Réun.Cons.int.Explor.Mer, 180:221-227.

Groupe MEDIPROD. 1974. Généralites sur la campagne CINECA-CHARCOT II (15 Mars - 29 Avril 1971). Tethys 6(1-2):33-42.

Holzlohner, S. 1975. On the recent stock development of Sardina pilchardus Walb. off Spanish Sahara. ICES CM 1975/J:13.

Huber, K. E. Mittelstaedt and G. Weichart. 1977. Meteorfahrt N°30 23-1, 2-3, 1973. Seegebiet NW Afrika zur Hydrographie der Gewässer von Marokko. Physikalische und chemische Daten. Publ.D.Hydrogr.Inst. 2149/18. Meeresk.Beob.Ergbn. 46:131 p.

Hugues, P. and E.D. Barton. 1974. Physical investigations in the upwelling region of Northwest Africa on RRS Discovery Cruise 48. Tethys 6(1-2):43-52.

Johannesson, K., L. Villegas et M. Lamboeuf. 1975. Estimation acoustique quantitative de l'importance et de la distribution des ressources sardinières de la côte atlantique du Maroc. Trav.Doc. Dèv.Pêche Maroc (11):23 p.

Jones, P.G.W. and A.R. Folkard. 1970. Chemical oceanographic observations off Northwest Africa with special reference to the process of upwelling. Rapp.P.-v. Réun. Cons.int.Explor.Mer, 159:38- 60.

Krzeptowski, M. 1975. Sardine in Polish catches in the Spanish Sahara region during the years 1971- 1974 ICES CM 1975/J:18.

Krzeptowski, M. 1978. The results of Polish investigations on sardine inhabiting the western Sahara shelf. Contribution No. 112 to the Symposium on the Canary Current Upwelling and Living Resources. Las Palmas, Avril 1978.

Lamboeuf, M. 1974. Résultats de la prospection acoustique du cap Milionia à la pointe Stafford (Avril-Mai 1974). Trav.Doc.Dev.Peche Maroc (9):15 p.

Lamboeuf, M. 1977. Estimation acoustique quantitative de l'abondance et de la distribution de la sardine marocaine en Janvier 1977. Trav.Doc.Dev.Peche Maroc (22):13 p.

Lamboeuf, M., J. Burczynski, S. Benchecifi, et M. Chbani 1981. Campagne de prospection des stocks pelagiques du cap Cantin (Maroc) au cap Timiris (Mauritanie) en Juillet 1980 (Resultats preliminaires) Trav.Doc.Dev.Peche Maroc (28):26 p.

Lamboeuf, M., J. Burczysnki, S. Bencherifi, M. Chbani et A. Elminowicz. 1982. Evaluation acoustique de la biomasse des stocks de sardine au Maroc de 1979 a 1981. Combinaison des estimations du sonar et du sondeur vertical. Contribution No. 92 Symposium on Fisheries Acoustics - Bergen 1982.

Le Corre, P. and P. Treguer. 1976. Contribution a l'etude des sels nutritifs et de la matiere organique dissoute dans l'eau de mer. Caracteristiques chimiques du Golfe de Gascogne et des upwellings cotiers de l'Afrique du Nord-Ouest. These Doc Eta, Univ. Brest, 490 p.

Le Floch, J. 1974. Quelques aspects de la dynamique et de l'hydrologie des couches superficielles dans l'Ouest marocain Campagne CINECA-CHARCOT I et III. Tethys 6(1-2):53-68.

Le Saos, J.P. and J. Talarmin. 1976. Campagne CINECA IV (23 Juillet-Aout 1973) Hydrologie et Courantologie au large des cotes du Maroc. Universite de Bretagne Occidentale, Laboratoire d'Oceanographie physique, 77 pp.

Maigret, J. 1974. La sardine sur les cotes de mauritanie Sardina pilchardus Walb.) Bull.IF AN A3: 714-721.

Manriquez, M. et F. Fraga. 1982. The distribution of water masses in the upwelling region off Northwest Africa in November. Rapp.P.v-.Reun.Cons. int.Explor.Mer, 180:39-47.

Marchal, E. et T. Boely. 1977. Evaluation acoustigue des ressources en poissons du plateau continental Ouest-Africain des Iles Bissagos (11°N) a la pointe Strafford (28°N). Cah. O.R.S.T.O.M. Ser.Oceanogr. XV(2):139-161.

Mascareno, D. 1970. Consideraciones sobre la hidrologia entre cabo Leven y punta Durnford. Bol.Inst. Espa.Oceano (141):19 p.

Mascareno, D. et R. Molina. 1970. Contribution a l'etude de l'upwelling dans la zone canarienne africaine. Rapp.P.-v.Reun. Cons. int.Explor.Mer,159:61-73.

Minas, H.J., L.A. Romana, T.T. Packard et M.C. Bonin. 1974. La distribution de l'oxygene dans un upwelling cotier (NW de l'Afrique) et dans celui d'une divergence au large (Dome de Costa Rica).

Minas, H.J., L.A. Codispoti and R.C. Dugdale. 1982. Nutrients and primary production in the upwelling region off Northwest Africa. Rapp.P.-v.Reun.Cons.int.Explor.Mer, 180:148-183.

Mittelstaedt, E. 1982. Large scale circulation along the coast off Northwest Africa. Rapp.P.-v. Reun.Cons.int.Explor.Mer, 180:50-57.

Moal, R.A. 1957. Etude comparee de quelques caracteres de Sardina pilchardus sur la cote occidental d'Afrique. Cons.int.Explor.Mer, Comite sardine, No. 87.

Nehring, D. et S. Holzlohner 1982. Investigations on the relationship between environmental conditions and distribution of Sardina pilchardus in the shelf area off Northwest Africa. Rapp.P.-v.Reun.Cons.int.Explor.Mer, 180:342-344.

Rodriguez-Roda, J. 1958. Estudio comparativo del crecimiento de las sardinas Sardina pilchardus Walb. de Barbate et Larache. Inv.Pesqu.(13):3-36.

Rouch, J. 1931. Le Maroc maritime francais. Notice meteorologique et oceanographique. Mem.Soc.Scie.nat.Maroc, (28):22p.

Roux, G. 1937. Isothermes mensuels provisoires de l'eau de mer a la surface au large des cotes du Maroc. Memoire presente au Congres de la Recherche Scientifique dans les territoires d'Outre-Mer-Paris.

Rubies, P. and I. Palomera. 1977. Abundance and distribution of sardine eggs and larvae off Northwest Africa-April-May 1973. ICES CM 1977/L:7 Plankton Committee.

Schemainda, R., D. Nehring and S. Schultz. 1975. Ozeanologische untersuchungen zum produktions-potential der Nordwestafrikanischen wasserauftriebsregion 1970-1973 Geod. Geogh. Veroff. R. IV H.16: 85 p.

Sedletskaya, V.A. 1973. Reproduction de la sardine marocaine. In Probleme de l'ichthyologie. 13(6):1017-1023.

Sedykh, K.A. 1978. The coastal upwelling off the Northwest Africa. ICES CM/C:12 Hydrography Committee.

Sedykh, K.A. 1979. Etude de l'upwelling pres de la cote de l'Afrique du Nord Quest part l'Institut Atlantique de Recherches Scientifiques de la peche et de l'Oceanographie (Atlan. N.I.R.O.). In Rapport du Groupe de Travail ad hoc sur les poissons pelagiques cotiers ouest. Africains de la Mauritanie au Liberia. (26°N-5°N) COPACE/PACE/Series/78/10:93-99.

Smed, J. 1982. The oceanographic data base for the CINECA region, Rapp.P.-v.Reun.Cons.int. Explor.Mer 180:11-28.

Speth, P. and H. Detlefsen. 1982. Meteorological influences on upwelling off Northwest Africa. Rapp.P.-v.Reun.Cons.int.Explor.Mer, 180:29-34.

Thiriot, A. 1976. Les remontees d'eau (upwelling) et leur influence sur la production pelagiques des cotes atlantiques du Maroc., Bull.Inst.Peche Marit., Casablanca (22):5-12.

Tomczak, M. Jr. 1977. Continuous measurement of near-surface temperature and salinity in the NW African upwelling region between Canary Islands and Cap Vert during winter of 1971-1972. Deep-Sea Res. 24:1103-1119.

Tomczak, M. Jr.1978. De l'origine et la distribution de l'eau de remontee a la surface au large de la cote Nord-Ouest Africaine. Ann.hydrogr. 5(6):5-14.

Tomczak, M. Jr.1982. The distribution of water masses at the surface as derived from T-S diagram analysis in the CINECA area, Rapp.P.-v.Reun.Cons.int.Explor.Mer, 180:48-49.

Treguer, P. and P. Le Corre. 1979. The ratios of nitrate, phosphates, and silicate during uptake and regeneration phases of the Moroccan upwelling regime. Deep-Sea Res. 26: 163-184.

Villegas, L. et A. Goodlad. 1974. Resultats de la campagne de prospection acoustique entre la pointe Stafford et Saidia (November-December 1973) Trav.Doc.Dev.Peche Maroc (5) 12 p.

Villegas, L., M. Lamboeuf et A. Goodlad. 1973. Resultats de la campagne de prospection acoustique entre le cap Blanc et le cap Juby-Aout 1973 Trav.Doc.Dev.Peche Maroc (2):12 p.

Wiktor,K. and K. Chlapowski. 1970. Some remarks on the hydrological conditions of the waters of the North West African Shelf in the months from June to August 1967 -Rapp.P.v.Reun.Cons.int.Explor.Mer. 159:79-85

Wisokinski, A. 1980. Donnees supplementaires sur la peche et les ressources polonaises de la sardine dans la region du COPACE. In Rapport de la deuxieme reunion du Groupe de Travail sur la sardine Sardina pilchardus Walb. COPACE/PACE/Series 79/15:86-94.

Wooster, W.S., A. Bakun and D.R. McLain. 1976. The seasonal upwelling cycle along the eastern boundary of the North Atlantic. J.Mar.Res., 34:131-141.

Worthington, L.V. 1958. Oceanographic data from the RRS "Discovery II" I.G.Y. Cruises 1 and 2, 1957, W.H.O.I.Refer.58.30:152 p.

Wozniak, St. 1970. Some observations on upwelling in the area of Cape Blanc. June-August 1963. Rapp.P.-v.Reun.Cons.int.Explor.Mer, 159:74-78.

Wust, G. 1935. Schichtung und zizkulation des atlantischen ozeans. 2. Die stratosphare. D.A.E. "Meteor" 1925 - 27(6)1:288p.