THE MANAGEMENT OF CHILEAN PELAGIC FISHERIES WITH EMPHASIS ON THE SPANISH SARDINE (Sardinops sagax musica)

by

Alejandro Zuleta and Juan R. Serra
Undersecretariats of Fisheries
Teatinos 120
Santiago, Chile

1. INTRODUCTION

Pelagic fisheries are the main type of fisheries that have been developed in Chile. They represent over 80 percent of national landings of marine products at present, with exports of fish meal and oil standing at close to two hundred and fifty million dollars, and therefore are one of the country's most important export activities.

The impressive increase in landings by more than five times since 1973 is the result of a substantial increase in two resources: Spanish sardine (Sardinops sagax), and jurel (Trachurus murphyi), which were caught in insignificant amounts at the end of the sixties. Up to 1978, the increase in the catch from these resources, plus smaller amounts of other species, provided raw material for the industry which had been left with considerable idle capacity by the anchovy (Engraulis ringens) crisis.

Since 1978, and as a result of the boom in fisheries, a new investment process was started which represents an important increase in catching and processing capacity. However, as at the beginning of the decade of the sixties, the new investments were not based on knowledge of the long-term productive possibilities of the resource but rather on its unexpected and fortunate increase.

To manage these fisheries adequately, consideration should be given to their fluctuating nature. This aspect has not always been recognized by the agencies responsible for their management. This paper includes a description of these fisheries and the actions and problems involved in managing them.

2. DESCRIPTION OF CHILE'S PELAGIC FISHERIES

Chile's pelagic fisheries are located within a system of currents along the eastern border of the Southern Pacific Ocean (Fig. 1). The area includes the following three fisheries units:

The following species are involved: anchovy (Engraulis ringens), horse mackerel (Scomber japonicus peruanus), jurel (Trachurus murphyi), common sardine (Clupea (strangomera) bentincki), and Spanish sardine (Sardinops sagax musica). With the exception of the common sardine, which is only caught in Talcahuano, the remaining species are present in the three fisheries units in a greater or lesser degree (Table 1). The northern zone is the most important fisheries unit because of the quantity of landings and installed industrial capacity. In 1981, landings amounted to 2,159,341 tons, which represented 70 percent of the country's total catch. The other fisheries units caught 51,000 and 492,000 tons, respectively. This paper will refer to fisheries in the northern zone, mainly Spanish sardine, which is the system's dominant species.

Table 1. Landings by Species of the Chilean Pelagic Industrial Fishery

Source: IFOP

Figure 1

Geographical location of the Chilean pelagic fisheries

Figure 2

Total catch, by species, taken in the Chilean Northern Pelagic Fishery (1961–1981)

2.1 Catch

Figure 2 shows the quantities of anchovy, Spanish sardine, jurel and horse mackerel caught in the northern zone between 1961 and 1981. Changes in the abundance of the four species are clearly reflected by catches, the most important being the collapse of anchovy (1977) and the change, between 1973 and 1977, from practically monospecific fisheries (possibly succession fisheries would be more correct) to multispecific fisheries, resulting from the great increase, mainly of Spanish sardine, jurel and horse mackerel.

In 1978, Spanish sardine became the dominant species in the system, amply surpassing the other three in 1979, with a record catch of 1,592,000 tons in 1980. In 1981 it decreased to 1,425,000 tons.

Jurel was second in importance in 1978, and after a slight decline in 1979–80 it increased substantially in 1981 totalling 435,000 tons.

At the beginning of 1977 anchovy showed a marked fluctuation of about 100,000 tons, typical of a collapsed resource.

Finally horse mackerel, witih a maximum catch of 170,000 tons in 1978, after sustained growth, showed a somewhat erratic behaviour.

It is important to point out the level of total catches in the northern zone in the years in which anchovy was dominant (1961–1971) and in the years when Spanish sardine was dominant. The level reached since 1979 with Spanish sardine as the main species is twice as great as that reached in the 60's with anchovy as the principal species.

2.2 Fleet and fishing effort

The fishing fleet of the northern zone is composed of purse seiners. This fleet had a maximum of 251 boats in 1965 and then declined until 1974, when it reached 100 units. It began to increase again in 1965 to 128 boats in 1980 (Figure 3).

The purse-seiner fleet of the northern zone is composed of three small fleets which correspond to the most important ports, i.e., Arica, Iquique and Antofagasta (includes Mejillones). The most important changes, as regards the number of boats, take place in Iquique, it being the evolution of this small fleet which mainly accounts for the changes in the fleet of the northern zone.

As a result of the incorporation of new boats in Iquique and Arica, the number of boats began to grow again in 1974 but much more moderately than in the 1962–1965 period.

The increase in size of the boats is expressed by the capacity of the average fish-hold. Figure 3B shows the evolution of the size of the boats in the fleets of Arica, Iquique and Antofagasta (including Mejillones). The increase in the average capacity of the fish-hold is the result of the incorporation of larger fishing units, withdrawal of the older and smaller units, transferred to other ports and also to other fisheries, such as Talcahuano for example (Serra, 1978). It may also be observed that most of the renewals in the fleet are made in Iquique, where the curve continues to increase after 1970; on the other hand, it becomes stabilized at the other ports.

Figure 3

Evolution of the fleet of the Chilean Northern Pelagic Fishery (1958–1981) A = number of boats, B = boat size, expressed as mean hold capacity

Table 2. Technological evolution of the fishing gears and systems

CB: Average hold capacity,
ECOS: Ecosonda
PB : Power block
B. ABS: Pump
B. CAPS: Capsule pump
RED ½": Net ½"
RED 1 ½": Net 1 ½"
SISTEMA PETREL: Petrel system
AVION: Airplain
? : Supposed year of introduction
- : Without data
I : Year of introduction
NS : Beginning of night survey
* : Mainly on 300 – 350 m³ Hold capacity size fishing boats.

Serra (being printed) states that, together with the historical growth of the fleet, there is a gradual improvement in fishing gear, such as the incorporation of the power block, absorption pumps, acoustic equipment, nets, airplanes for prospecting activities and collaboration in fishing operations. Table 2 shows the years in which this equipment was incorporated and the percentage of the fleet affected. Subsequently, in 1978, other changes were made such as the replacement of the 13 mm mesh size anchovy net by a 38 mm mesh size sardine net. Night-time fishing was also generalized during this year with the incorporation of aerial surveys. Actually, night-time fishing in the northern zone was started in 1976, but without the use of airplanes.

Due to the difficulty of obtaining data regarding the time spent searching, fishing effort is measured by the number of trips, using two units: total of standard trips and trips with standard success. The total number of trips is obtained by adding the fishing and non-fishing trips. The criterion used to separate results by species is to assign the fishing trips to the dominant species in the landings.

Estimates of the fishing effort by species have been used to obtain indexes of catches per unit effort for the purpose of analysing changes in stocks (Serra, manuscript).

2.3 Stock abundance

To describe the changes in stocks in past and recent years, use has been made of catch per unit effort and of the catch itself as stock indexes. Catch has been used under the assumption that there is a good correlation between the latter and stocks, when the effort is big and there are no limitations to the volume of catch. Catch trends for different species have been commented on in a previous paragraph.

It is now recognized that catch per unit effort is not a good index to describe changes in stocks quantitatively (MacCall, 1976; Ulltant, 1976; Schaaf, 1975). Nevertheless, as may be seen in Figures 4 and 5, it presents a similar trend to the catches (Figure 2) for different species. This is confirmed in the case of Spanish sardine, for which data are provided by an analysis of the virtual population (Serra and Zuleta, 1982), in which an estimate was obtained of the stocks expressed by the average biomass, shown in Figure 6, where it may be seen that stocks of this species increased since 1974 in a similar pattern.

Catch and catch per unit effort are useful in describing the phase of explosive growth of these resources qualitatively. However, their use is considered to be quite limited to describe their stabilization and decline.

In 1981 and 1982 acoustic surveys were made in June-July and July-August respectively (Serra and Zuleta, op.cit.). These surveys covered the area from the border with Peru to 30- Lat.S. and up to 200 n.m. The estimated biomass of Spanish sardine in the area from the border with Peru as far as Antofagasta (24- Lat.S.) was 5,500,000 and 5,100,000 tons for each year respectively.

With the method for analysing virtual population, an estimate was obtained of the biomass of the average population for the years 1974 to 1981. Results show that in 1980 and 1981 stocks of Spanish sardine, from age three onwards, were at a level of 8,500,000 tons. The difference from the results obtained with the acoustic method is being analysed.

Figure 4

Catch, effort and CPUE of the Chilean Anchovy Fishery of the northern zone (1961–1977)

Figure 5

CPUE of mackerel, jackmackerel and Spanish sardine of the Chilean Pelagic Fishery of the northern zone (1965–1981)

Figure 6

Change in the mean biomass of the Chilean Spanish sardine (1974–1981) estimated by VPA (from age 3)

3. HISTORIC REVIEW OF MANAGEMENT

3.1 Promotion stage

During the 1957–1963 period, the Government aimed its efforts at promoting the development of the industry and fisheries research.

The development of the industry was favoured by government policy which stimulated investment through credit, tax exemptions and import privileges. This policy was established for the purpose of providing a labour alternative in the northern zone of the country to absorb unemployment originating in the crisis of the saltpetre industry in that area. The incentive to invest increased even more as a result of the great expectations arising from the spectacular development of the anchovy fishery in Peru.

On the other hand, research on pelagic resources was developed through two technical assistance projects, one with the government of Germany and the other with UNDP/FAO. The results of these projects were the Brandhorst Report (1963) and the establishment of the Fisheries Development Institute the same year. These initiatives which were of a general nature and were oriented towards the promotion of fisheries activities, led to research programmes which served as a basis for others and constituted the beginning of systematic research on these resources.

The characteristic of this stage is the accelerated development of fisheries based on an optimistic assumption about anchovy stocks, which would subsequently lead to considerable over-investment.

3.2 The anchovy crisis

Free access to fisheries led to an explosive development of fishing effort and capture, resulting in great pressure on the anchovy stocks and economic inefficiency, which caused a serious crisis in this activity in the years 1965 and 1972–1973. During 1965 the Government, through the Corporation for the Development of production (CORFO), took action after the situation arose to ameliorate the industrial crisis derived from over-investment and the unforeseen changes in resource stocks.

At the time, the Department of Fish and Game of the Ministry of Agriculture, which was responsible for the management of fisheries, tried to apply a regulation on volume of catch, which did not secceed because it did not have a sound enough technical basis and lacked the necessary elements for enforcement.

The 1972–1973 crisis took place under different circumstances. In the preceding years the Fisheries Development Institute carried out a research programme on pelagic resources, through which an important amount of information was gathered. However, no regulation was legally adopted, and the only thing to be mentioned in this respect is an agreement between the Ministries of Fisheries of Peru and Chile to establish a moratorium of one week for the capture of individuals of less than 11.5 cm in total length exceeding 20 percent of the landing in fisheries activities carried out in the area of Ilo (south of Peru) and Arica (northern Chile). The purpose of this measure was to protect the breeding stock which remained of a population unit shared by both countries. This agreement lasted until 1973, when a change took place in the political regime of Chile.

After this event and until 1978 the Fisheries Development Institute continued to carry out research and updated analysis of the state of pelagic fisheries, many of the latter having been carried out at the request of the Fisheries Protection Division, as the Department of Fish and Game was later called, but no measures were adopted except two military edicts, originated by the regional governments outside of the institutional framework of the fisheries administration. The first one (December 1973) established a moratorium of one month for Africa and Iquique and the second (December 1977) a closed season for the area along the coast to avoid conflicts between industrial and artisanal fishermen.

The concern of entrepreneurs about the collapse of the anchovy passed quickly, due to the fortunate substitution of species, as a result of which other species, mainly Spanish sardine, replaced anchovy reaching even higher and unexpected catch levels.

3.3 Structure of Fisheries Administration

A restructuring process of the public sector was completed in 1978, with the organization of the administrative function in two agencies: the Undersecretariat of Fisheries (SUBPES) and the National Fisheries Service (SERNAP), both of which depend on the Ministry of Economy; the first is of a normative and the second of an operative character, devoted mainly to controlling management norms and gathering statistical data. The management function is more clearly defined and is provided with the technical and legal elements and administrative authority required to make it more effective.

The immediate result of these changes in the management of pelagic fisheries was, on the one hand, the formulation of a national management programme for pelagic resources (SUBPES, 1980) with a better conceptualization of fisheries problems in every aspect and, on the other, a more determined action to manage it which was actualized in the regulations described below.

4. PROCEDURES FOR STOCK ESTIMATION AND DESIGN OF REGULATIONS

An analysis was made in 1981 of the situation of pelagic resources (SUBPES, 1981), especially of Spanish sardine, for which all available information was taken into account, i.e., patterns of landing curves in similar fisheries, catch per unit effort, exploitation rate, modal sizes, dependency model of catch/effort, which were integrated in order to make a diagnosis.

Two patterns in particular became evident through analysis based on the history of landings in pelagic fisheries of other countries (sardine and horse mackerel in California, sardine in Japan, and menhaden on the Atlantic coast of the United States), in addition to the country's own landings. The first beginning with a phase of rapid development up to a maximum followed by an abrupt decline, and the second starting also with an accelerated development phase but, after reaching a peak, passing through a “plateau” of great instability with severe fluctuations and ending by declining abruptly.

As regards Spanish sardine, in accordance with the landing curve (Figure 2) and the behaviour of the curve of catch per unit effort, in which would indicate combination of the growth phase of the stock, it may be expected that, under a regime of non-regulation or inadequate regulation, one of these two patterns will develop with the consequences which are already known.

An exploitation rate of 43 percent as estimated for Spanish sardine (SUBPES op.cit.), compared with the exploitation rate of 30 percent (which results when F=M), is excessive. This criterion to define the adequate level of exploitation emerged from the empirical evidence provided by the analysis of several similar fisheries in the world (Troadec, et al., 1980).

Furthermore, the decrease in modal sizes between 1978 and 1980, from 32.5 cm to 28 cm total length, can also be interpreted as the result of levels of exploitation which are too high.

Another element considered in diagnosing the state of the resource was the use of a dependency model of catch/effort. This model more adequately describes the dynamics of pelagic resources synthetically (Clark, 1974; Gulland, 1976) which, (Figure 7), when fisheries operate without regulation as in the case of the stock of Chilean anchovy, reaches a maximum level of yield very close to the critical point, when the population is susceptible to catastrophic changes in its dynamics.

All of the above indicated the existence of a situation of high risk, which made it advisable to reduce the rate of exploitation in order to increase the probability of resource permanence at satisfactory levels of abundance for the fisheries activity.

In line with this, the following regulatory measures acquired importance:

1. Prohibition of the use of purse seiners along a strip of 1 km from the coast:

   Knowledge of the spatial distribution of these species of economic importance, which sustain the pelagic fisheries of the northern zone, indicates that the coastal strip is a breeding area for the species. As the younger individuals of the immature fraction of the population are protected, the source of recruitment is protected.

2. Determination of a minimum size for Spanish sardine and jurel:

   The minimum size for Spanish sardine and jurel was estimated on the basis of the criterion of the critical age, thus aiming at a more efficient use of the growth of the species (over-fishing by growth) and at the same time obtaining the benefit of increasing the expectancy of an individual reaching sexual maturity.

3. Determination of the quota or allowable capture of Spanish sardine in the northern zone for 1982:

   The allowable catch was determined as follows:

   1. Projection of the catch of Spanish sardine for 1981, which was based on the data available up to September of that year and seasonal patterns observed during 1978, 1979 and 1980.

   2. Establishment of a catch rate of 39 percent instead of 43 percent as a gradual reduction aimed towards the desirable level of 30 percent.

   3. Calculation of the allowable catch using the catch equation of Baranov, assuming that the existing biomass in 1982 was the same as that in 1981. The estimated quota was 1,300,000 tonnes.

   During 1982, with more complete information on the age structure for the 1974–1981 series, mortality estimates were verified. New estimates of stock size were obtained through the VPA and the acoustic evaluation method (Serra and Zuleta, op.cit.). In this respect, mention should be made of the application of the methods of successive age groups, catch curve and empirical physio-logical equation (Pauly, 1980).

   All these data were used in an evaluation of the diagnosis, which was corroborated, and are being considered for the calculation of an eventual quota during 1983.

   Furthermore, the VPA provides an optimistic prospect for the short term (two years) regarding stocks, because no decrease is manifest in the strength of the year classes which are entering the fishery.

Figure 7

Catch-effort curve of anchovy in the Chilean northern zone Effort is expressed in total standard trips (TVE) Depensatory curve was fitted by hand

5. ADOPTION OF REGULATIONS

In 1981, the Undersecretariat of Fisheries, as a result of the evaluation of the state of pelagic resources, concluded that it was necessary to adopt management measures. For this purpose three regulations were promulgated with respect to:

1. Restriction of size of Spanish sardine and jurel (Decree Law No.458)

2. Restrictions to be applied to pelagic fisheries in the northern zone on the use of purse seiners in breeding areas (Decree Law No.459)

3. Catch quota for Spanish sardine fisheries in the northern zone during the yearly season of 1982 (Decree Law No.460)

The first regulation fixes a minimum size of 20 cm total length for Spanish sardine and a 26 cm fork length for jurel. Nevertheless, a catch of smaller sizes than that established for both species, is allowed only as by-catch, at a rate not exceeding 20 percent, of the main species landed.

A second regulation forbids the use as fishing gear of nets of a depth exceeding 20 fathoms and a net with a mesh size equal or below 38 mm between knots, during a period from 1 November of each year to 31 May of the following year, in fisheries along a strip one mile wide from the coast between parallels of 18–28'00" latitude south and 25–00'00" latitude south.

The third rule establishes an allowable capture of 1,300,000 tonnes of Spanish sardine in the maritime zone under national jurisdiction, between parallels 18–28'00" and 25–00'00" of latitude south for the period 1 January to 31 December 1982. Regulations also establish that, after the quota has been completed, a catch of Spanish sardine is only permitted as a by-catch, in a quantity not exceeding 20 percent of the main species of the landing.

The quota was subsequently supplemented by 116,000 tons (Decree Law No. 263), which represented the establishment of an exploitation rate of 42 percent.

6. ENFORCEMENT OF THE REGULATIONS

SERNAP controls the enforcement of the above regulations. For this purpose the agency, which is regionally structured, has several offices located along the coast in cities near to the main fishing ports (Arica, Iquique, Antofagasta). Enforcement is carried out from each of these regional bases in two steps.

First, in coordination with the Maritime Office, coastal surveillance is maintained from observation points on land and ocean patrols, to control the entrance of boats with forbidden gear into breeding areas. Landings are inspected in order to control minimum sizes in catches and regulations and control actions are disseminated among fishermen and the community. In this stage the monitoring of landings to control the allowable catch was carried out by SERNAP through its fishery statistics system with the support of information provided by the Fisheries Development Institute. Subsequently, in a second step, samples of the specific composition and volumes of landings were taken in addition to the above tasks, to control the quota and minimum sizes caught more accurately.

As a third step, it is necessary to improve enforcement activities substantially, which requires, on the one hand, that this function be provided with better means and, on the other, that greater emphasis be placed on preventive activities to support the purpose of the regulation.

7. RESULTS OF THE APPLICATION OF REGULATIONS

Among the rules applied, the most important is the evaluation of allowable catch. This measure gave rise to conflict because the quota was filled before the end of the term for which it was established. In view of this, fishing entrepreneurs started a series of negotiations with the authorities in connection with the socio-economic problem that originated when activities were stopped. This, which was aggravated by the serious recession in the national economy, presented authorities with the dilemma of having to favour the activity or apply the regulation. Finally, the first alternative was chosen.

The main argument used to support this decision was that the end of the season for catching Spanish sardine was near, according to its seasonality, and that therefore the application of a supplementary quota involved an acceptable marginal risk, considering that it was thus possible to solve the problem that had arisen. The supplementary quota was also completed before the end of the season, causing the same difficulty again. As a result, and based on the reasons already mentioned, finally no limitation was set for Spanish sardine catches.

The Under-secretariat of Fisheries, concerned about the difficulties of achieving the management purpose for this fishery, decided to set up a Consultative Technical Commission, composed of representatives of fishing enterprises, the Fisheries Development Institute, the National Fisheries Service and the Under-Secretariat itself.

Finally, the non-pessimistic short-term projection resulting from the second evaluation of this resource indicates that measures compatible with a wider variety of conditions, both economic and social as well as biological, still would be permissible. In this sense the quota by itself has not been a satisfactory regulatory mechaism and needs to be modified.

8. REFERENCES

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Clark, C.V., 1974 Possible effects of schooling on the dynamics of exploited fish populations. J.Cons.CIEM, 36(1):7–14

Gulland, J.A., 1976 The stability of fish stocks. J.Cons.CIEM, 37(3):199–204

MacCall, A.D., 1976 Density dependence of catchability coefficient in the California Pacific, Sardinops sagax caerulea, purse seine fishery. Rep.Calif.Coop.Ocean.Fish.Invest., (18):136–48

Schaaf, W.E., 1975 Status of the Gulf and Atlantic menhaden fisheries and implications for resource management. Mar.Fish.Rev., 37(9):1–9

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Serra, J.R., Cambios de la abundancia de los recursos de sardina espanola (Sardinops sagax musica), jurel (Trachurus murphyi) y caballa (Scomber japonicus peruanus) del norte de Chile. (MS)

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SUBPES, 1980 Programa Nacional para la evaluacion y pronostico de recursos pelagicos, 1980–1984. Santiago, Chile, Subsecretaria de Pesca.

SUBPES, 1981 Fundamentos tecnicos de los Decretos Nos. 458, 459 y 460, del Ministerio de Economia, Fomento y Reconstruccion. Santiago, Chile, Subsecretario de Pesca.

Troadec, J.-P., W.G. Clark and J.A. Gulland, 1980 A review of some pelagic fisheries in other areas. Rapp.P.-V.Reun.CIEM, 177:252–77

Ultang, Ø., 1976 Catch per unit effort in the Norwegian purse seine fishery for Atlanto-Scandian (Norwegian spring spawning herring). FAO Fish.Tech.Pap., (155):91–101