ANCHOVY MANAGEMENT BY QUOTA

by

R. McInnis
National Marine Fisheries Service
USA

Introduction

This paper describes the experience of the United States National Marine Fisheries Service in managing the US fisheries for northern anchovy (Engraulis mordax), the purpose being to provide background for discussion.

Since 1978, the US fisheries for anchovy have been managed under Federal regulations based on the Northern Anchovy Fishery Management Plan (FMP). In that FMP, the Pacific Fishery Management Council (PFMC) recommended objectives for managing the fisheries and a combination of harvest quotas, seasons and area closures to achieve those objectives. This paper will describe the approach taken to manage a resource with a widely fluctuating biomass, in which management by an average maximum sustainable yield is not adequate. The resource is an extremely important prey species for commercial and recreational species and is essential to a small purse-seine fishery and to a large recreational fishery as bait. The following brief descriptions of the stock and the fisheries were excerpted from the FMP (PFMC, 1978).

Stock

The northern anchovy is a common pelagic schooling fish of the west coast of North America, that ranges from the Queen Charlotte Islands (Miller and Lea, 1972) to Magdalena Bay, Baja California (Ahlstrom, 1968; Mais, 1974). The population has been divided into northern, central and southern sub-populations, based on variations in meristics and electrophoretic separation of the blood serum protein, transferring (Vrooman et al., 1981), as shown in Figure 1.

The boundary between the northern and central sub-populations is not well defined. Sampling in the boundary area between the two sub-populations has been nearshore and too sparse to define the division. The boundary probably fluctuates seasonally and annually in the area just north of San Francisco, i.e. approximately 38-N.

The central sub-population, the most abundant of three sub-populations (Vrooman and Smith, 1971), extends from 38-N to approximately 30-N at Punta Baja, Baja California, in the south. The bulk of the biomass in the central sub-population is consistently located in the southern California Bight, bounded by Point Descanso, Mexico, in the south, and a series of banks and islands extending in a northwest-southwest direction from San Miguel Island to Sixty-Mile Bank (Mais, 1974). The San Pedro and Port Hueneme anchovy reduction fisheries take place in the channel area of the southern California Bight bounded in the north and west by the city of Santa Barbara and Santa Cruz Island and to the south and east by Santa Catalina Island and Dana Point, an area approximately 90 miles long and 22 miles wide. Based on egg and larvae surveys and recent acoustic surveys conducted by the California Department of Fish and Game, approximately 1/6 of the central sub-population inhabits the channel on average.

The division between the central and southern sub-populations is relatively well defined. The southern sub-population extends south from approximately 30-N, Punta Baja, to approximately 24-N, Magdalena Bay (Ahlstrom, 1968; Mais, 1974). This sub-population is harvested to some extent by the Mexican anchovy fishery.

In conclusion, the central sub-population ranges from approximately 38-N to 30-N and extends offshore approximately 200 miles. The central sub-population is distinct from both the northern and southern sub-populations and is the target of both US and Mexican anchovy fisheries. Regulations discussed in this paper are applied only to the central sub-population and only to the US fishery on that sub-population.

Fig. 1 Geographic distribution and spawning seasons of the three subpopulations of northern anchovy, Engraulis mordax.

Fisheries

Anchovy fisheries in both the US and Mexico can be categorized by the uses to which their catch is put. The largest volume of anchovy is caught for reduction to fish meal and oil. Much smaller amounts are caught for use as bait by commercial and recreational fishermen. Finally, a small portion of the total harvest is canned for human consumption. Anchovies command a higher unit price for the latter two uses.

The largest US catches are taken by the commercial “wetfish fleet” which fishes for reduction purposes. This fleet also fishes for sardines, jack mackerel, Pacific mackerel, bonito, bluefin tuna and squid, but anchovy accounts for the preponderance of the multi-species harvest. Vessels of the fleet range in length from 12 to 30 m and use round-haul nets (purse seine and lampara). Most of southern California vessels use purse-seine gear while vessels fishing in the Monterey Bay area occasionally use lampara nets.

Fishing effort for anchovies is mainly in southern California waters at present. Small and relatively stable catches are made in Monterey Bay. Several vessels land anchovies at Port Hueneme but the major reduction landings are made at Terminal Island. The principal areas of catch are the Catalina Channel and the Santa Barbara Channel. The California fleet fishing anchovies for reduction has fluctuated during recent years but the basic fleet has remained about 25 vessels. The purse-seine fleet is the remnant of a much larger fleet that harvested sardines. That resource disappeared in the 1950s, apparently because of over-fishing combined with very low recruitment over a period of several years.

The commercial anchovy fishery in Mexico is conducted by boats based at Ensenada. The anchovies taken are used for reduction and canning and a small amount may be taken for use as bait by the albacore fleet. The Mexican commercial fleet contains a number of rather small purse seiners, averaging less than 45 tonnes hold capacity. These vessels fish close inshore and relatively close to Ensenada. Part of the fleet consists of larger vessels that fish for anchovies part of the year, then move to the Gulf of California to participate in the sardine fishery. Six large purse seiners of 270 net-tonnes capacity joined the fleet in 1976 to fish anchovy on an all-year basis. The Mexican catch of anchovies grew rapidly during the late 1970s, due to the increased fishing capabilities and construction of new reduction-plant facilities at Ensenada.

Issues confronting Managers

Development of a fishery management plan for northern anchovy was prompted by the perceived need to address issues in three general categories: (1) conservation of the resource, (2) allocation among competing resource users, and (3) international consideration for a transboundary stock.

Many Californians are keenly concerned about protection of the anchovy resource, whether their primary interest is commercial or recreational fishing or the health of the coastal ecosystem in general. They recall the collapse of the California sardine resource and fishery (or have grown up hearing tales of the collapse) in the 1950s. The State fishery-management agency has been blamed by some for allowing over-fishing of sardines. As a consequence, recreational fishermen and conservation interests have organized on a local basis to ensure that interests, other than the short-term economic interest of commercial fisheries, are considered in fishery management decisions. A side effect of the sardine experience has been a readiness of interest groups to scrutinize carefully and to challenge the conclusions and biological opinions of government agencies. These groups certainly are a force in the management policy-making process.

Fishery managers and scientists involved with this anchovy fishery also are compelled to move cautiously with exploitation of this stock because of the experience of other nations with percipitous declines in similar fishery resources. The Peruvian anchovy experience is one case particularly familiar to these people.

One characteristic of the anchovy resource which influences management policy is that the abundance of spawners fluctuates widely over short periods. The fluctuation occurred even before a significant fishery existed. Management which relies on fixed regulatory measures such as fixed quotas would not satisfy the needs of the fishery or the resource from year to year. The resource can fluctuate to such an extent that the word “average” has little practical meaning for efficient management. If the average yield were harvested annually, the resource could be greatly over-fished in some years.

A parallel concern with protecting anchovy population productivity is providing a sufficient standing stock of anchovy to support large populations of higher predators. Anchovy are a food source for many species of larger fish which are important to commercial and recreational fishermen. Marine birds and mammals also rely on anchovy as forage to varying degrees. In addition to the public interest in maintaining large, healthy populations of these predator species, by maintaining a sufficient food supply, Federal law mandates that the needs of some predators be considered of higher priority than any fishery. Both the Marine Mammal Protection Act and the Endangered Species Act prohibit activities which would disadvantage or jeopardize the covered populations. Degradation of their habitat, including substantial reductions in their food supply, would violate these laws.

Since anchovy predators are opportunistic feeders for the most part, their diets consist mainly of anchovy when anchovy are abundant and of substitute prey when anchovy are not abundant. High levels of anchovy abundance are sufficient to support predators and a fishery.

Once it is determined that there are sufficient anchovy to fulfill the basic forage and reproductive needs, the question is what is the best use for the amount above that threshold level. The views on this issue fall into two divergent categories. One opinion is that the best use for any “surplus” anchovy is to bolster the forage supply. Those holding this opinion do not object to small volume fisheries for human consumption and for bait to be used by recreational and commercial fishermen. The other opinion on this issue holds that, if the basic reproductive and forage requirements are met, the anchovy above that level should be available for harvest. Those holding this opinion generally support the anchovy reduction fishery as a means of taking advantage of the anchovy “surplus”.

The idea of catching fish for the purpose of reducing them to oil and meal is abhorrent to some people. In fact, California State law has prohibited the reduction of whole fish since 1919. The anchovy reduction fishery has been allowed to operate under special permits since 1965. Low ex-vessel values for anchovy to be reduced and the existence of substitutes for the end-products add to the arguments of those who believe the value of increased forage outweighs the value of a reduction fishery. However, a value for incremental increases in forage supply has not been calculated, nor is it likely that an objective value can be assigned.

The final major issue driving anchovy management policy is the complications arising from the transboundary distribution of this stock. Apparently the centre of the sub-population varies annually and through the season. Activities of the Mexican fishery and the US fishery impinge on the same stock and on each other. Both nations' fisheries have demonstrated their potential for harvesting large quantities of anchovy. As yet, peak fishing years for the two fleets have not coincided. One nation regulating its fishermen's efforts to catch a transboundary stock such as this will not be as effective as complementary, cooperative management by both nations.

Management objectives

After listening to the various interest groups and considering the National Standards for fisheries management, the Pacific Regional Fishery Management Council proposed a set of objectives to be met in anchovy fishery management. The following objectives are stated in the Anchovy Plan:

1. To prevent over-fishing of the central sub-population of northern anchovy (Engraulis mordax) within the United States' Fishery Conservation Zone, and to promote conservation throughout its range.

2. To allow a fishery for anchovies within the US Fishery Conservation Zone and to pursue such a fishery so as to achieve the optimum yield on a continuing basis.

3. To maintain an anchovy population within the US Fishery Conservation Zone of sufficient size to sustain adequate levels of predator fish, birds and mammals.

4. To avoid conflicts between US recreational and commercial fishermen.

5. To promote efficiency in the utilization of the central sub-population of anchovies within the US Fishery Conservation Zone.

One unstated and underlying objective of the Plan was to define allocations of the anchovy resource in such a manner that annual changes in the total amount available for harvest would not require annual debates over the allocation principles.

Harvest quotas and allocations

The basic regulatory control on the US anchovy fishery is the annual quota. To address concern over the annual variation in the size of the anchovy stock, the overall quota hinges on the estimate of spawning biomass. The basic rules adopted for calculating the total optimum yield (OY) for the central sub-population of northern anchovy resource are as follows:

1. If the spawning biomass (B) is less than 100,000 tonnes,
   Optimum yield = 0

2. If B is greater than 100,000 tonnes but less than 1,000,000 tonnes,
   OY = 18,000 tonnes

3. If B is greater than 1,000,000 tonnes,
   OY = (B-1,000,000) ÷ 3 or
   OY = 18,000 tonnes, whichever is greater

This harvest strategy was selected on the basis of impacts predicted by a bio-economic model of the fishery. That model (PFMC, 1978 - Appendix VI) was used to compare several alternative strategies, some more conservative and others more liberal than the one selected. Key impacts analysed were the effects on the mean biomass, the mean harvest and the number of years in which fishing would be prohibited due to low biomass.

This strategy was expected to provide first for protection of a spawning stock, then for small, high priority fisheries and for a portion (1/3) of the surplus to be used for lower priorities during years of high anchovy abundance. In this way, 982,000 tonnes of the first 1,000,000 tonnes were reserved for reproductive stock and to support predator populations. When the estimated spawning biomass exceeded one million tonnes, two-thirds of that excess is reserved from harvest as well.

The first allocation of the total quota among fisheries was an attempt to make a reasonable allocation of the central sub-population between the US and Mexico. In the absence of a negotiated agreement with the Government of Mexico, the Plan establishes an allocation unilaterally. Based on the average distribution of anchovy larvae, the US/Mexico allocation was set at 70:30. Given this division, 70 percent of the harvest at each level of spawning biomass is assigned to the US zone.

Allocations among uses within the US zone are ranked as follows:

1. Bait and human food

2. Domestic reduction industry (fishermen and processors)

3. Domestic fishermen delivering to foreign processors

4. Foreign fishermen

To date, anchovy has been taken only for priorities (1) and (2).

Announcement of quotas

The anchovy fishing year, for the purpose of accounting toward the quota, is 1 July through 30 June of the following year. Actual fishing for reduction begins on 1 August in Monterey and on 15 September for the major fleet in southern California. Given these opening dates, the annual quota should be announced before 1 August. In practice, a preliminary determination of spawning biomass, harvest quotas and expected harvests is published on 1 July for public review and comment. After considering the comments received, the final determinations are made and published on 1 August each year.

The biomass estimations are made each year by scientists at the National Marine Fisheries Service's Southwest Fisheries Center. A method for making these estimates was described by Smith (1972) and is summarized in Appendix I of the Plan (PFMC, 1978). New techniques have been developed since this Plan has been in effect (Parker, 1980; Stauffer and Picquelle, 1980). Since the newer method of biomass estimation is believed to be superior to the traditional method and yields substantially different estimates, some aspects of the Plan may need to be revised to accommodate our new perception of the anchovy resource. The basic concepts of a spawning biomass reserve, proportional harvest of the biomass in excess of the reserve and priority allocations among fisheries likely will be retained.

Other regulations employed

In addition to quotas, the anchovy reduction fishery is subject to seasonal and areal closures. Basically, the reduction fishery is prohibited from taking anchovies within three miles of the coast of southern California. That closure extends to six miles in some areas. There are other small area closures all of which have the same primary intent, that is to alleviate the potential conflicts with recreational and bait fisheries. An incidental benefit of these closures is protection of juvenile anchovy which tend to concentrate near shore. The seasonal closures were established to coincide with the peak spawning season (winter) and the height of recreational fishing activity (summer). The winter closure was motivated to some extent by a desire to avoid disturbing spawning aggregations but it also had a sound economic basis. Anchovy have lower oil content during the winter and are less valuable to processors. The summer closure reduces conflicts between commercial anchovy fishing and recreational fishing activity which peaks during the months of July and August. Those conflicts include competition for fishing space and for anchovy, which recreational fishermen value highly as bait.

Impacts of regulations

During the five years anchovy fishing has been regulated according to the current Plan, the quota has been reached only once and that happened very late in the season. According to the traditional method of biomass estimation on which quotas have been based, the population has been at relatively high levels of abundance since the mid-1970s. Consequently, the impact of harvest quotas on the resource and the fishery has been almost negligible to date. The quotas have increased public confidence that the fishery management agencies are monitoring and regulating the fisheries responsibly. With changing perceptions of the anchovy population and apparent declining abundance, harvest quotas will play an increasingly important role in regulating the reduction fishery. We remain confident that a combination of a spawning and forage reserve with a harvest quota based on annual biomass estimates will protect the anchovy resource and provide for predator populations, while allowing a reduction harvest when the resource is abundant.

This policy of setting annual quotas according to an established allocation formula was successful in easing debate when each year's quotas were announced. Debates resumed, however, with the introduction of a new fishery model.

The area and season closures have reduced the potential for direct conflict between recreational and commercial fishermen. Commercial fishermen have borne the cost of avoiding conflicts by foregoing fishing near to shore and during the summer months.

Administrative and enforcement costs

The cost of regulating the US anchovy fisheries according to the Northern Anchovy FMP includes the following:

Costs associated with estimating spawning biomass on an annual basis vary according to the method of estimation. When the Plan was approved in 1978, the annual cost of conducting a larva census to estimate spawning biomass was approximately $556,000. Since that time, modifications in estimation techniques have reduced the amount of vessel and personnel time required. Currently, the cost of estimating spawning biomass by the egg-production method is expected to be approximately $200,000 annually. This cost could decrease substantially if the frequency of surveys were reduced to less than once a year. At present, the costs total to approximately $325,000 annually for biomass estimates, monitoring and enforcement.

Discussion

The principles by which the US anchovy fisheries are regulated were attractive to resource managers but the approach requires a great deal of information on the resource and the fisheries it supports. Ideally, there should be sufficient background to construct a functional bio-economic model for comparing alternative harvest strategies. Allocating the allowable harvest is facilitated greatly if managers, fishery participants and other interested parties have confidence in the model and the biomass estimation procedures.

In general, the management programme employed here is costly to implement. One research priority identified in the FMP was to develop more cost-effective systems for estimating the spawning biomass. Although a new method has been developed, it still is expensive to determine biomass reliably each year. We are exploring the possibility of using biennial or triennial surveys and indirect evidence (fishery data, etc.) to estimate abundance changes between surveys. If a mixture of methods proves acceptable, the frequency and expense of surveys can be reduced even further.

Two by-products of developing a more cost-effective method of estimating biomass were a more precise estimate and a refined understanding of anchovy population dynamics. That refined understanding significantly altered the bio-economic model and, when the revised model has been reviewed thoroughly, the FMP, regulations and allocation formulae will be amended. The basic principles, however, likely will be retained.

Perhaps the greatest short-term impact of changing the model and biomass estimates is a loss of confidence in the science on which the fishery regulations are based. In time that confidence will be restored but, while changes in the allocations are being considered, this lack of confidence on the part of the fishery participants will cloud the deliberations.

As troublesome as the re-evaluation of the domestic allocations may be, the unresolved issue of how to share the resource and management responsibility with Mexico is far more complex and critical for the effective management of this resource. While discussions among scientists from both countries have taken place in the past, meaningful progress toward joint or complementary management has not been made. This lack of progress is due, in part, to tuna-management related problems creating a less than productive atmosphere for other fishery negotiations and to the differences in management goals between the two nations. Whatever the cause, the lack of agreement is delaying effective management and protection of the entire central anchovy sub-population.

References

Ahlstrom, E.H., 1968 An evaluation of fishery resources available to California fishermen. Univ.Wash.Publ.Fish., (4):65–80

Mais, K.F., 1974 Pelagic fish surveys in the California Current. Fish Bull.Calif.Dep.Fish Game, (162):72 p.

Miller, D.J. and R.M. Lea, 1972 Guide to the coastal marine fishes of California. Fish Bull.Calif.Dep.Fish Game, (157):249 p.

PFMC (Pacific Fishery Management Council), 1978 Northern anchovy fishery management plan. Fed.Reg., 43(141):31655–783

Parker, K.R., 1980 A direct method for estimating northern anchovy, Engraulis mordax, spawning biomass. Fish.Bull.NOAA/NMFS, 78:541–4

Smith, P.E., 1972 The increase in spawning biomass of northern anchovy, Engraulis mordax. Fish.Bull.NOAA/NMFS, 70:849–874

Stauffer, G.D. and S.J. Picquelle, 1980 Estimates of the 1980 spawning biomass of the central sub-population of northern anchovy. Admin.Rep.Southwest Fish.Cent., (LJ-80-9):41 pp.

Vrooman, A.M., P.A. Paloma and J.R. Zweifel, 1981 Electrophoretic, morphometric and meristic studies of sub-populations of northern anchovy, Engraulis mordax. Calif.Fish Game, 67:39–51

Vrooman, A.M. and P.E. Smith, 1971 Biomass of the sub-populations of northern anchovy, Engraulis mordax Girard. CALCOFI Rep, (15):49–51

Table 1. Yearly California Anchovy Landings

Table 2. Anchovy Landings at Ensenada, Baja California

* preliminary

Table 3. Commercial Landings and Live-Bait Catch of Anchovies in California, 1939–1981 (metric tons)

* for all uses
** preliminary