Generally speaking, experience with the fisheries of northern latitudes and upwelling systems has shown that moderate levels of exploitation (fishing mortality), relative to the natural mortality the fish resource population is adapted to, will not usually affect the capability of that resource to regenerate itself in the medium to long term. This may also be true even if the species and size composition are somewhat modified from that occurring under “virgin” conditions, as is usually the case with moderate to high levels of exploitation. Perhaps this is because such systems are mostly inhabited by species with unspecialized feeding habits, that can respond in a rather elastic fashion to changes in abundance of one or another of several main prey items. The reproductive mode of such species tends to be based on broadcast spawning with large numbers of eggs dispersed widely throughout the stock area, of which only a very tiny proportion need to survive to ensure stock replenishment.
In contrast, many tropical marine communities are much “older” in evolutionary terms and are dominated by more specialized species adapted to certain specific food items and habitats; in such communities, in which environmental extremes are less common than in, say, polar ecosystems, there are more but less abundant species. These communities may be more susceptible to serious ecological stresses, including overfishing. For these resources, emphasis may need to be given to zonation and non-exploitive development as well as harvesting.
The need to conserve options for future generations incorporated in the concept of sustainable development, has been a goal of fisheries management for decades. To what extent have the approaches used to date been successful? Some explicit current approaches in marine fishery management are, inter alia, Maximum Sustainable Yield (MSY) and Maximum Economic Yield (MEY), referring, respectively, to the maxima in terms of physical yield and of net economic value and social benefits, derivable from a given resource (Panayotou, 1988).
The concept of MSY is used in the UN Convention on the Law of the Sea as the main benchmark for optimal exploitation; it becomes clear, however that “single-species MSY” criteria have several drawbacks in terms of sustainable development. The latter will require other benchmarks based on whole-ecosystem criteria, since one of the key features of marine ecosystems is their “interconnectedness” (Apollonio, 1994) (see Annex I). A serious reduction in the abundance of a “target” resource as a result of heavy exploitation can change the relative abundances of all the species in the marine fish community, since they are linked to the target species in question, as competitors for food, breeding space, adequate environmental conditions etc. This change in relative abundance is not necessarily a cause for concern, as long as the species involved do not fall below the level at which the stock is endangered, and the system retains the flexibility to return to its original condition once exploitation is reduced, within a reasonable time period. From this multispecies perspective, the MSY concept makes no allowance for interaction between species (predator/prey equilibria, for example), or for whole-system effects such as a decrease in the stability of the system (fishery-stock-ecosystem), and while it is applicable to a simple, single-species fishery, its applicability to a fish community, or a multi-species fishery as a whole, is much less obvious (Caddy and Mahon, 1995).
Particularly where a species is a target of exploitation, its capacity to replace itself through reproduction may be reduced in the presence of competitor species (not always of commercial value) which can partly displace the depleted species from its place (ecological niche) in the marine community, and lead to a different proportion of each species spawning than originally present. The target species may be an important food item for other species, so that the abundance of other members of the food web are affected by its intensive exploitation. The extent to which this new population equilibrium can sustain itself differs from system to system, and the question of stability, important preliminary preconditions in deciding between the feasibility of different sustainable development strategies for each of the systems concerned.
In practice, unfished populations are normally dominated by large, old fish with slow growth (that add little biomass per unit time for a given consumption of food resources). A moderate level of fishing increases the production of new biomass by removing old fish and thus making room for younger fish, for which the rate of increase in biomass due to growth and reproduction exceeds losses due to natural. However, an increase in fishing effort (and therefore investment in fishing capacity) yields progressively smaller increases in biological production, until some point of Maximum Biological Production (MBP; Caddy and Csirke 1983) for the stock is reached, when the stock is making its maximum combined contribution both to natural predators and to the fishery. Total production, supporting predators and man, declines with further increases in fishing effort. Even though landings may subsequently increase slightly, it is now at the expense of other components of the ecosystem. Fishing at the level of effort that yields the MSY may result in an excessive reduction in mean size, mean age and catch rate for the target population, and will reduce the number of times an adult organism reproduces in its life history, thus making the stock more susceptible to the effects of environmental fluctuations on breeding success.
It should be noted (Garcia, Gulland and Miles, 1986; Sissenwine, 1978) that MSY, as for other practical management reference points, requires good fishery data to be collected, but MSY also requires to be exceeded, such that the overall catches begin to decline, before it can be properly defined. This leads the fishery into a state of overexploitation which is not easily reversible (e.g. FAO, 1994a). MSY as an overriding objective of fishery management also exceeds the effort level equivalent to the maximum economic yield, and a number of other socially desireable objectives. Certainly, the extra cost of fishing required to move from MEY to MSY can hardly be justified (FAO, op. cit.). Attempting to define the level of fishing effort at which the MEY can be achieved has its problems, especially if competing fleets are involved, since the appropriate fishing effort varies with the changing costs of fishing and fish prices.
It has been found that, for some fisheries, the MSY target can also lead to population collapses, since, as is often the case, the current state of the resources is not accurately known, and effort “overshoots” can easily occur. As a broad generalization, achievement of the Maximum Biological Production (MBP), the spawning stock biomass that maximizes recruitment, or the MEY, all imply lower rates of exploitation than the MSY target, which corresponds to a higher degree of capitalization of the fleet than is justified by the rapidly diminishing extra returns per unit extra cost when moving from the lower rates of fishing implied by the MEY towards those implied by the MSY.
The response of the ecosystem to moderate exploitation may be more stable when fishing effort and death rate due to fishing remain more or less constant, despite natural fluctuations in abundance, than with a constant harvest but wide variations in the rate of harvest. Stability may also be improved when fishery removals for each species in a community are adjusted to be a similar proportion of the natural deaths due to the predation each species suffers from. (Large species with a low natural death rate can sustain much smaller rates of removal than small ones, and other species with a high death rate.)
Experience has shown (FAO World Conference on Fisheries Management and Development, 1984) that the major economic gains from harvesting wild resources come from ensuring that harvesting capacity does not exceed the capacity of the resource to sustain this harvest while reproducing itself. At the same time, reducing costs and wastage during the phases of capture, transformation and transportation, ensuring substitution of imported products by those locally available, maximizing the value of the transformed products, as well as reducing unnecessary capital expenditures on fishing vessels and other equipment surplus to the potential economic yield, are all goals that yield major economic gains in the long run. Experience has also shown that neither the physically (MSY) nor the economically (MEY) optimal harvesting rates are stable “end points” of development, and that in fact the only “meta-stable” point in the system is when expenditure on harvesting equals the economic return from fishing; i.e., a zero-rent situation. It is evident, therefore, that an active research and resource monitoring capability and an associated control and surveiliance capacity are essential components of sound fishery management.
The setting of objectives for fishery development and management should be based, inter alia, on an assessment of the fishery resources available, the capacity of the primary and secondary sectors, the markets to be satisfied, and the socio-economic context in which the development is to be achieved, in particular the impact of any new development on traditional fishermen. Sometimes, the objectives are multiple and not always compatible, and difficult choices may have to be made; it is therefore important that the objectives be explicit and their relative advantages made clear. Moreover, since the conditions in which fisheries are conducted are dynamic, objectives appropriate at one stage may not be so at a later stage; hence periodic evaluation of the validity of objectives is necessary. The difficulties of setting either total allowable fishing effort or catch are due to, inter alia, the variability of the resource and the effect of fishing pressure on it, and the relative difficulty of controlling and/or enforcing either total allowable fishing effort or catch, especially if other (foreign) fishing fleets are exploiting the resource of concern.
Fishery management should be conceived and understood not as a constraint upon rational exploitation (i.e., sustainable development) but as an essential tool for such development. Nevertheless, it can only hope to be successful if, apart from the careful definition of objectives mentioned above, those authorities mandated to pursue such objectives (i.e., to manage the fishery) have well defined lines of responsibility and accountability, and work in close co-operation and communication with the fishing industry.
Trawling and dredging can affect the marine environment by, for instance, destroying organisms of the sea bed or sea-grass meadows by mechanical disturbance and siltation. Illegal fishing techniques such as the use of dynamite or chemicals to capture reef fish also damage the habitat (Alcala et al., 1987; Maclean, 1988). These matters should be handled through legislation with at-sea enforcement, and by enlightening fishermen as to the longer-term negative consequences of using destructive fishing methods.
Intensive fishing modifies the abundance, age structure, species composition and potential for reproduction of fish stocks. Moderate levels of exploitation remove old, slow-growing individuals and reduce the abundance of large predators thereby increasing the productivity, hence the sustainable yield, of the remaining stocks. High levels of exploitation may reduce to “commercial extinction” the abundance of older mature age classes and of large, slow-growing species in general. Although very few cases of actual species extinction by fishing alone have been documented, intensive fishing reduces genetic diversity of the species concerned.
The fact that fishing gear and methods of fishing are generally aimed at a marketable size of fish in some fisheries has not prevented capture and discard of considerable quantities of species and sizes that, with further development, could be marketed as a valuable source of protein. In recent years, public concern about the so-called “by-catch problem” has been directed particularly towards intentional or incidental capture or entanglement of marine mammals, birds and turtles by operative fishing gear, or its accidental capture by lost or discarded fishing gear; so-called “ghost” fishing (Breen, 1989). Reducing such incidental captures to the minimum should be aimed at by improved gear design and fishing practices. Synthetic netting materials do not break down; moreover, such netting may continue to attract and trap animals approaching to feed on animals already captured in it. In fact, the level of global discardings (Alverton et al., 1994) estimated at 27 million tons, is a significant proportion of the global marine catch.
However, fishing by trawling, drift netting and seining, even when carried out with improved gear in a responsible fashion, will inevitably capture non-target species in small numbers. Some types of fishing gear cannot readily be substituted and cannot always be suitably modified to meet excessively rigorous criteria. Application of unduly restrictive norms may therefore bring many forms of commercial fishing, whether large-scale or artisanal, to an end. The hardship thus caused to human coastal populations in general, and to fishing communities in particular, especially in developing countries, must be taken into account in applying such conservation measures, if in fact the problems could be greatly reduced by a reduction in fishing effort or areas/seasons fished.
A major geographical expansion of the range of action of fishing fleets, which even prior to the UN Convention on the Law of the Sea were operating in all world oceans, has taken place over recent decades (FAO, 1992e). In the same period, developing coastal countries have seen their wild marine resources exploited first by foreign distant-water fleets and, more recently, by national fleets sometimes through joint ventures between coastal States and distant-water fishing nations. Whatever the strategy of exploitation followed, a system of resource monitoring is an essential component of the national fishery regime. Experience has shown that high levels of exploitation not only promote the dominance of less valuable species in the catches at the expense of valuable target species, but lead to inefficient use of specialized equipment to catch and process fish. This often has to be purchased by developing countries with hard currency. Hence, uncontrolled development adversely affects net export earnings and foreign exchange reserves, as well as increasing the instability of marine resources. A healthy resource base can be maintained by rigidly controlling fleet development. We may note that high operating costs (for fuel etc.), in theory, can place a brake on over-investment. By contrast, fuel subsidies for marine fisheries tend to have the opposite, negative effects on the resource base, and reduce options for sustainable development.
The ability of a marine resource to recover its pristine abundance if exploitation ceases for a medium to long period of time is generally assumed. For example, following the two World Wars, when fishing ceased in the North Sea, this assumption proved to be substantially justified (Beverton and Holt, 1957). There has also been a recent major recovery of the Peruvian anchoveta resource, after a collapse due to heavy fishing and environmental change in the 1980's. Environmental influence appear to play a predominant role for resources in upwelling areas in which stock fluctuations are naturally high. It should be borne in mind that, for many small pelagic fishes, notably sardines and anchovies, the effects of these periodic changes in favorability of the environment persist even when the absolute abundance itself varies, as may happen under intensive fishing. The capacity for stock recovery after over-exploitation may therefore not be simply explained by reduced fishing pressure, but may also require favourable environmental conditions.
In contrast, in the case of some complex tropical biological communities, heavy fishing may change species composition dramatically, and it is less certain whether the reversibility of degraded communities is likely, at least in the short term. For example, removal of grazing fish from coral reefs or run-off of sewage from shore can lead to blanketing by algae and to death of the living coral that provides the necessary substrate for reef fishes. Reverses to this trend may not automatically occur in the short term once the damaging impact is removed.
The most reliable generalization in the theory of fishing appears to be that, under unlimited access to resources and fishing grounds, a “boom and bust” situation results, with periods of overexploitation resulting from uncontrolled investment in fleets, and strong depletion, leading eventually to vessels moving to other fisheries or being retired, with (hopefully) a stock recovery initiating another cycle of investment. Some of the features of such a sequence of events are shown in Figure 10. Obviously, the possibility of such a “cyclical” phenomenon has serious implications for the resource, the fishing industry, and the communities dependent on them. Perhaps fortunately for many living resources, in the past, the “break-even” catch rate that corresponded to a “break-even” economic yield, particularly in a period of increasing fuel costs, has often been low enough to allow stock recovery. Two contrasting factors now threaten the possibility of achieving optimal usage of resources: growing coastal populations, with their needs and their impact on the coastal environment; and new improvements in technology, cheaper fuel, vessels and equipment. Larger, more efficient nets, more-seaworthy vessels, with better position-and fish-finding equipment, allow this economic break-even point at which fishing ceases to be profitable, to be reached at progressively lower levels of resource abundance. These largely undocumented effects threaten the renewability of many resources and places an onus on the need for strict management control, monitoring of technological changes and the specific allocation of rights of access.
An optimal harvesting strategy for “wild” resources needs continual adjustment on the basis of monitoring and research in a variety of fields and is only possible, sustainable and ecologically sound, at a level of harvesting that yields considerably less than the maximum that the resource is able to provide during the first decade of unrestrained fishing. Such evidence as we have on the age composition of fishing fleets (e.g. Caddy 1993b) suggests that a steady investment in fleet capacity from year to year, may be less typical than ‘pulses’ of new fleet capacity entering a fishery over a short period, which greatly complicates management and contributes to non-equilibrium conditions.
One other practical aspect of sustainable development is the application of more selective fishing gear and methods. By-catches of non-marketable or undersized fish or of non-target species (birds, mammals) are not wanted by the fishermen, but fishing gear and methods are rarely fully selective and fishermen dump what cannot be sold. For instance, the by-catch from shrimp trawling alone is probably in excess of 5 million tons annually (Alverson et al., 1994).
Technical advances in fishing gear and fishing methods very often lead to a breakdown of traditional management systems for which modern management systems have not successfully substituted. The need for appropriate allocation of marine space and resources, with direct community participation in the decision-making, is vital to the achievement of sustainable development.
The International Conference on Responsible Fishing (Cancún, Mexico, May 1992; FAO, 1992c) adopted the Declaration of Cancún. This Conference, inter alia, requested FAO to prepare an International Code of Conduct for Responsible Fishing, taking the Declaration into account. The main elements of such a Code were discussed at the FAO Technical Consultation on High Seas Fishing and are proposed in (FAO, 1993c); it is likely to cover: fishing operations (e.g., deployment of fishing vessels and gear, navigation regulations, vessel and gear marking, trans-shipment of catches, certification and crew training, fishery patrol and protection, flagging); fishery management; trade in fish and fish products (stressing the importance of harmonizing environmental measures with the maximizing of trade); fishery research (see section 6, below); aquaculture development (with particular attention to the relation between the culture and the natural environment and its wild resources); and the inclusion of coastal fisheries into integrated coastal-area management schemes. (Extracts from the text of the Cancún Declaration are provided in Annex V).
It should be recalled that the question of, and need for, such a Code of Conduct was first raised at the Nineteenth Session of the FAO Committee on Fisheries (Rome, April 1991), and the FAO Technical Consultation on High Seas Fishing (Rome, September 1992) supported the proposal for the elaboration of such a code; some preliminary outlines for which are already emerging (FAO, 1995a).
Regulation of fishing gear specifications, and the enforcement of minimum allowable individual fish size in the catches of targetted species, seek to compel fishermen to modify mesh size and to deploy fishing gear so as to control the sizes caught, but few if any such regulations refer specifically to gear selectivity for species. There is an urgent need for further research on more selective fishing gear with respect to species as well as sizes, and a better understanding of the appropriate areas and seasons when undersirable by-catch is minimized.
Figure 10. Phases in an idealized fisheries ‘cycle’ for an open access resource; assuming successive periods of investment in catching capacity, fishing effort and landings, biomass and consequent recruitment and mean landed size (from: Caddy, 1984)
Some States have already introduced legislation controlling fishing methods, and making escape devices obligatory in certain types of fishing gear. This has often led to conflict between fishermen, administrators and the public, but further development of escape devices for small fish, and the use of biodegradable components of gear so as to avoid “ghost fishing” by lost nets or traps, are important and need greater support. To prevent illicit disposal of damaged nets, methods for filament marking are being developed that enable the net's origin to be traced.
Fishery resources contribute to national food security as coastal States aim at obtaining production of adequate supplies, of sufficient quality, to ensure a healthy life for their populations. Fish in the diets of persons living in many developing countries is often critical for their nutrition, and coastal populations may obtain much of their animal protein intake from fish (FAO 1991a, 1995c, d). This is especially true in Asia, where over 1 billion people depend heavily on fish for their animal protein. World consumption of fishery products is very variable, and average figures are relatively meaningless, but since supply is comparatively constant and prices are generally rising in industrialized countries, we may expect an increased flow of fish from developing to developed countries in the future (FAO, 1993b). This will have serious consequences since consumption of fish is perceived to confer health benefits as a supplement to low-protein foodstuffs, allowing, in particular, the normal development of children otherwise dependent on a carbohydrate diet. many developing countries import significant quantities of processed fish with hard currency, and a policy of import substitution by local fishery products available within the national EEZ, a higher valuation of national fishery resources, and more effort allocated to their management, will all have positive effects on the economy, whether fish is used for food or export.
It has been anticipated that the shortfall in world fish production by the year 2000 will be at least 20 million tons, and this does not take into account the potential for collapse of many fisheries that currently provide much of the world's production and which are currently fully fished or even overfished (FAO, 1993g, 1995c). The consequences of a collapse in fishery production would be a likely increase in the real prices for marine products, but, of far greater importance, will have dramatic repercussions on the lives of millions of the poorest people; this greatly constrains the options available for the management of aquatic resources. The above-mentioned shortfall does not take into account the current conversion of roughly a quarter of the global marine production (especially that of small pelagic fish) into meal for livestock feed; a similar amount to the anticipated shortfall in “fish for food”. This conversion of fish to meal reflects the established demand for animal feed as well as difficulties handling and commercialization of large volumes and seasonal fleets of many small pelagic species for human food. The extensive use of animal protein for livestock feed nevertheless constitutes a significant loss of assimilable protein to human diets, and the further development and transformation of small pelagic fish for food should alleviate the plight of the poorest and generally increase the economic return to fishermen.
Regarding the effects of market demand on sustainable development and conservation of resources, the existence of a demand for a resource, information on its availability, and the absence of constraints on its marketing and trade, are all positive factors encouraging sustainable development in industry and agriculture. However, in the exploitation of renewable natural resources in the absence of a management system pressures for entry to the fishery lead to a surplus of fishing effort. Thus, if there is no resource management framework in place, all of these otherwise positive factors can unwittingly facilitate stock collapse. The transition from traditional use of natural systems to uncontrolled industrial use is a dangerous period for coastal States utilizing “wild” resources, as has also been observed in the forestry and the wood-products industry.
Centralized political systems and market-oriented economies can both lead to over-exploitation of the resources of natural systems, but for rather different reasons. The efficiency of a free market system stems from the fact that it minimizes the knowledge required for efficient economic decision-making, on the grounds that each individual in the chain of individuals between production and consumption should be free to follow his or her self-interest. This however dilutes the responsibility for the side effects of resource exploitation as a whole, and for the effects on the environment, which can be either at the production end (e.g., overfishing) or at the consumption end (e.g., pollution). In contrast, centralized systems remove individual and local responsibility for decisions, and weaken local control and concern for the environment. It would seem therefore that the need for overall control of the conditions or rules under which marine resouce exploitation takes place is independent of the particular political framework that applies.
It seems important that in the future, limitations on access and removal not be dictated solely by market value and demand, especially from the global market place, which is progressively less likely to be saturated for many fishery products. The negative impact that high demand may be having on the state of resources is of special concern for developing countries, where inadequate controls on access and removals exist. Here, the opportunity to provide “added value” by processing, quality control and sophisticated marketing, should be used to reduce uncontrolled export of primary commodities which reflect only a fraction of their eventual retail values on the markets of developed countries. Naturally, foreign-exchange earnings are a high priority for developing countries, but a proper calculation should include consideration of food security and the cost of replacement of national protein resources. One example is the trend to high-intensity harvesting of “trash fish” for shrimp feed in areas that formally yielded high-diversity, hgih-unit value fish for local markets through a low-intensity, diversified artisanal fishery.
Market demand has also been considerably enhanced by the significant growth of many human populations, by their tendency to move from rural and agricultural areas to large (and growing) cities and, in particular, to the coastal zone. These movements remain largely uncontrolled and place severe strains on marine (and often other) resources, which are still largely regarded as common property with open, cost-free access, often aggravated by uncontrolled human pressures on aquatic environments in general.
Principle 15 of the Rio Declaration of the UN Conference on Environment and Development (Rio de Janeiro, 1992) states that “In order to protect the environment, the precautionary approach shall be widely applied by States according to their capabilities. Where there are threats of serious or irreversible damage, lack of full scientific certainty shall not be used as a reason for postponing cost-effective measures to prevent environmental degradation.”
In cases of high uncertainty about critical areas or species, in particular, and to avoid potentially irreversible changes, the precautionary approach has been advocated to make development conditional upon scientific proof of its harmlessness, and this principle is now being extended to management of fisheries ecosystems (e.g. Garcia, 1994a, b; FAO, 1995g).
Although in absence of adequate data to setting exploitation levels, a precautionary approach is desirable, this approach should, where possible, be such as to encourage accumulation of data on which a more information-based management approach could be based. The mere existence of known links between different species in the food chain may not be, for example, an “appropriate and sufficient” cause for banning controlled exploitation which, if accompanied by pilot-scale fishing and properly planned shipboard data-gathering exercises, could yield much more precise indications of actual as well as potential impacts. Judging from experience acquired to date, the impacts of fishing on the food chain may be quite different from those expected. The most practical precautionary solutions offered to date, seem to be either to establish a low rate of exploitation based on reference point(s) below the MSY level (e.g. Caddy and Mahon, 1995), or to set up criteria for amounts and areas of harvesting of a pilot fishery, during which intensive data collection by observers on board fishing vessels could allow evaluation of the impact of different fishing methods, and gather the relevant data.
| 1. | THE PRECAUTIONARY APPROACH TO FISHERIES AND THE BURDEN OF PROOF | |
| 11. | Within the framework outlined in Article 15 of the UNCED Rio Declaration, the precautionary approach to fisheries recognises that fisheries systems are slowly reversible, proorly controllable, not well understood, and subject to changing human values. | |
| 12. | The precautionary approach involves the application of prudent foresight. Taking account of the uncertainties in fisheries systems and the need to take action with incomplete knowledge, it requires, alia: | |
| a. | consideration of the needs of future generations and avoidance of changes that are not potentially reversible; | |
| b. | prior identification of undesirable outcomes and of measures that will avoid them or correct them promptly; | |
| c. | that any necessary corrective measures are initiated without delay, and that they should achieve their purpose promptly, and that they should achieve their purpose promptly, on a timescale not exceeding two or three decades; | |
| d. | that where the likely impact of resource use is uncertain, priority should be given to conserving the productive capacity of the resource; | |
| e. | that harvesting and processing capacity should be commensurate with estimated sustainable levels of resource, and that increases in capacity should be further constrained when resources productivity is highly uncertain; | |
| f. | all fishing activities must have prior management authorization and be subject to periodic review; | |
| g. | an established legal and institutional framework for fishery management, within which management plans that implement the above points are instituted for each fishery, and | |
| h. | appropriate placement of the burden of proof by adhering to the requirements above. | |
| 13. | Key concepts in past discussions of the precautionary approach have been the burden of proof and the standard of proof (i.e., the responsibility for providing the relevant evidence and the criteria to be used to judge that evidence). Often, the precautionary approach has been taken as requiring a reversal of the burden of proof, such that human actions are assumed to be harmful unless proven otherwise. In regard to these concepts, it is recognised that: | |
| a. | all fishing activities have environmental impacts, and it is not appropriate to assume that these are negligible until proved otherwise; | |
| b. | although the precautionary approach to fisheries may require cessation of fishing activities that have potentially serious adverse impacts, it does not imply that no fishing can take place until all potential impacts have been assessed and found to be negligible; | |
| c. | the precautionary approach to fisheries requires that all fishing activities be subject to prior review and authorization; that a management plan be in place that clearly specifies management objectives and how impacts of fishing are to be assessed, monitored and addressed; and that specified interim management measures should apply to all fishing activities until such time as a management plan is in place, and | |
| d. | the standard of proof to be used in decisions regarding authorization of fishing activities should be commensurate with the potential risk to the resource, while also taking into account the expected benefits of the activities. | |
| (excerpt from FAO, 1995g) | ||
For marine resources as a whole, experience over the last few decades suggests that the number of important unexploited resources for which entirely new fisheries are feasible may be rather limited. Squids and mesopelagic fish (Garcia and Majkowski, 1990) are the main resources for which potential may still exist. For mesopelagic fish, potential yields could be high, but the net return on investment, given currently low unit values, high costs of fuel and the high level of harvesting technology required, may not be as great as some projections suggest.
The primary potential of mesopelagic fish is to replace larger proportions of small pelagic fish, such as sardines, sprats and anchovies, in the production of fish meal, thus potentially releasing the aforementioned small pelagic fishes for direct use as human food. This possibility depends on technological and marketing solutions being found and is urgent, given that demand for marine products is progressively exceding supply and is taking fish protein beyond the reach of the poor. In this case, the possible impact on other species in the oceanic food chain must be taken into account. The major opportunities still open for the sustainable development of most marine resources may lie in the reduction of wastage (e.g., that of finfish by-catch in shrimp fisheries in the tropics), and in allowing recovery of heavily fished resources to more productive levels, as is now being attempted by the new government of Namibia in its Exclusive Economic Zone, and in enhancing the quality of fish products by adding “value” to certain fish products prior to marketing and export.
Other resources, formerly considered underexploited include Antarctic krill, now apparently a slower-growing and longer-lived species than was believed formerly to be the case. Further exploitation is dependent on establishing a sustainable impact of fishing on other living marine resources of the Antarctic which depend on this species for food, even if this leads to some reduction of their long-term population levels. Here, as for high-seas resources, there is a need for risk evaluation that weighs possible adverse impacts against tangible benefits, and for decision to be taken on the equitable allocation of these benefits. Similar considerations have been raised in the North Atlantic about the advisability of heavy exploitation of small forage fish, such as sand eels and capelin, that are essental food for more valuable species such as cod, and for species under conservation, such as some sea birds (ICES, 1994b). In this case, the explicit requirements of predatory fish, or of sustainable populations of marine mammals and sea birds that feed on these resources, need to be given consideration.
Currently most feasible options for increasing the world fish catch may be summarized under the following seven headings:
New “wild” resources: Large untapped marine resources are very restricted in number, and their current exploitation may be inhibited by technical or economic factors, but include principally mesopelagic fish, small crustaceans and cephalopods. Their exploitation must be undertaken with an understanding of their linkages to other organisms of social/biological importance, may require appropriate new technology, and pose problems in transformation, marketing and equitable allocation.
Reduction of waste: Large proportions of edible by-catch in fishery operations are lost, either through being rejected at sea (e.g. Crean and Systems, 1994; Alverson et al., 1994), in storage, or during transformation and transport. This problem offers the greatest potential for immediate application of appropriate technology in all sectors. Another aspect of waste reduction of economic importance relates to the use of fuel-efficient fishing vessels (e.g. Buxton and Robertson, 1989).
Elimination of waste in financial resources: This offers perhaps the largest potential of all, given that fishery yield (physical and economic) declines above a very limited level of investment. Systems of controlling effort by limited licensing of vessels should, in theory, resolve this problem, but require costly involvement of governments in monitoring, research and control and surveillance. Systems of allocating harvesting rights to communities and/or the private sector will allow economic efficiency to be attained (e.g. gimbel, 1994), and permit legal redress against infringement of user rights by excess fishing or by pollution. We may note that some financial resources released from construction of excessive investment in the harvesting sector, should ideally be diverted into stock enhancement, habitat restoration, and technologically improved methods of monitoring, control and surveillance.
promotion of community development can lead to product diversity: A more equitable sharing of benefits from the exploitation of marine resources in the context of limited access will contribute to the well-being of coastal communities and encourage diversification of products and resource use. The example of Japanese community-based coastal fisheries indicates that this is a feasible and desirable objective that will place emphasis on artisanal fishery vessels equipped with appropriate technology (Nagasaki and Chikuni, 1989).
Community-based resource development, with individual rights eventually reverting to the community and re-allocated in proportion to potential yields, encourages an appropriate mix of marine resource use and land-based activities such as small-scale farming, sports fishing and eco-tourism.
Restoration of degraded ecosystems and depleted resources: To restore them to their full economic potential will be expensive, but will yield major economic returns. This will be essential in the case of, for example, semi-enclosed seas, lagoons, estuaries, reefs and mangroves, and will require actions by other sectors of the economy, and in the inland MCB discharging into coastal waters.
Marine aquaculture: The potential for this sector in inshore and local enclosed marine waters is seen as less of a panacea in the recent past; degradation of these waters and effects of high stocking levels have made themselves adversely felt. Its role in relation to food security by increasing fish yields is not unlimited, given that most currently cultivated marine finfish are predators and convert fish and other protein-rich meals to cultured fish. This is not true for plankton- and detritus-feeding molluscs such as mussels, or for seaweed (Doty et.al., 1987), whose cultivation offers great potential if markets can be found for these products.
Non-exploitive uses: Growing interest in the marine environment and its living resources can lead to economic benefits from eco-tourism, marine parks and aquatic activities. These will place a high premium on unpolluted and locally pristine environments, such as those contained, for example, in biosphere reserves (e.g. Batisse, 1990).
Some futuristic possibilities that are beginning to emerge from current technological and scientific investigations may also be suggested here. Most are untried and will require vigorous feasibility testing, with emphasis on economic cost-benefit analysis before large-scale application.
Enhanced productivity: “Seeding” of offshore areas by nutrients such as iron currently limiting oceanic productivity will promote phytoplankton growth and biological productivity. Similarly moderate levels of fertilization inshore may increase yields. In some circumstances, after careful evaluation, these mechanisms might be translatable into harvestable yield and might assist in fixing atmospheric carbon, thus contributing to a reduction of the “sierra” effect.
Offshore plumes produced by, for example, Ocean Thermal Energy Conversion (OTEC) systems (GESAMP, 1984a, b; Avery, 1994), could promote ocean productivity local to the point of discharge, as well as adding to energy supplies. Disposal of selected biodegradable wastes away from shelf areas may act in a similar way and possibly reduce coastal eutrophication.
Offshore aquaculture: The technology for offshore aquaculture is now being developed. The main limitation again is foodstock. Some experiments now underway on the use of algal growth on structures suspended in oceanic waters have suggested that commercial herbivorous organisms (e.g. crabs) may be reared on these structures.
Biotechnology: Biotechnology and the growing exploitation of biological diversity and genetic resources are applications that are just beginning but have the potential to make a significant economic contribution.
Large-scale artificial reefs: The potential for increasing yield of high-value reef species by increasing surface relief (ruggosity) of shelf areas has been tested with different degrees of success (GFCM, 1990). Whether it is economically feasible to extend such structures over large shelf areas and the extent to which they enhance production remains to be seen. This application will only be economically attractive with assignment of specific user rights.
