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1.3 Factors in the growth of agriculture in developing countries
Further intensification in prospect, with yield growth the mainstay of production increases
The production outcomes presented earlier will depend on further intensification of agriculture in the developing countries: yields will be higher, more land will be brought into cultivation and irrigated, and the existing land will be used more intensively (multiple cropping and reduced fallow periods).
Yield growth has been the mainstay of production increases in the past. It will be more so in the future, particularly in the land-scarce regions of Asia and Near East/North Africa. At present, average yields differ widely among countries. However, comparisons of average yields convey only limited information about the potential for lagging countries to catch up with the ones achieving higher yields. This is because agroecological conditions differ widely among countries and farming environments. For example, the 5.0 tonnes/ha average wheat yield of Egypt reflects the fact that wheat is irrigated. This yield is not achievable by countries in which wheat is, and will continue to be, predominantly rainfed in adverse agroecological conditions.
Therefore, agroecological differences among countries must be taken into account before any judgement can be passed as to the potential for yield growth. It is for this reason that a painstaking assembly and collation of data on yields achieved in the different countries in six agroecological environments (five rainfed and one irrigated-hereafter referred to as "land classes") was undertaken for this study. The resulting data are not perfect and it has not been possible to assemble sufficient information for China. But for the other developing countries these imperfect data can go a long way towards permitting an assessment of yield growth potential which is far superior to that based only on average yields.
With these caveats in mind, the dependence of the production outcomes presented earlier on yield growth, and how credible the yield projections may be, can be illustrated as follows: the average irrigated rice yield in the developing countries is today 3.7 tonnes/ha, but some countries achieve only 1.0 tonne and others 10.0 tonnes. The one-fifth of countries with the highest yields achieve an average of 6.7 tonnes. The country-by-country assessment of prospects for irrigated rice indicate that the average irrigated rice yield of all countries could be 5.2 tonnes/ha in year 2010. This means that in 20 years' time the average irrigated rice yield for all countries may be still below that achieved today by the top fifth of countries with the highest yields. This may appear conservative, but it is a "best guess" outcome of the judgements made for individual countries taking into account both differences among countries in the quality of irrigated lands as well in the socioeconomic environments which condition the pace of adoption of yield-increasing technologies. Similar considerations apply also to the rate at which average yields of other crops in each land class may edge upwards towards those achieved by the best performing countries today. Thus, the average yield of rainfed wheat in sub humid land may grow from 1.7 to 2.1 tonnes/ha, compared with the 2.3 tonnes/ ha achieved today by the top fifth of countries. For sub-humid rainfed maize the corresponding numbers are for the average yield to grow from 1.8 to 2.6 tonnes/ha compared with 2.8 tonnes/ha achieved by the top 20 percent of countries today. And so on for other crops and land classes (for more details see Chapter 4).
Naturally, further growth in yields, even at the lower rates projected here compared with the past, will not come about unless the research effort continues unabated. The effects of research on yield growth may manifest themselves in different ways compared with the past: more impact through lower, evolutionary growth in average yields based on adaptive and maintenance research and less through the achievement of quantum leaps in yield ceilings. As a result the inter-country yield differentials may narrow a little, though they will remain very wide. For example, for wheat and rice, average yields of countries at the bottom of the yield league may still be in 2010 only one-fifth of those achieved by the 10 percent of countries at the top; and those of the largest producers may still be only one-half those achieved by the countries at the top. Moreover, continuing research effort is needed for the crops and unfavourable environments which have been neglected in the past, as well as for preventing declines and maintaining and perhaps increasing yields in those farming conditions where yields achieved are near the ceilings of experiment station yields.
Land in crop production to expand and to be used more intensively
The developing countries (excluding China) have about 2.5 billion ha of land on which rainfed crops could achieve reasonable yields, depending on the technology used. Over 80 percent of it is in the two land-abundant regions of sub-Saharan Africa and Latin America/Caribbean. The differences in land/ person ratios among regions are enormous, with Asia and the Near East/North Africa region having particularly low land availabilities per caput. Of this total land, about 720 million ha are currently used in crop production and another 36 million ha of land so used comes from desert land which has been irrigated. The projections of this study would require increases in the different countries which sum up to about 90 million ha. Thus, by the year 2010, the total land in crop production could be some 850 million ha. The expansion would mostly be in sub-Saharan Africa and Latin America/Caribbean, some in East Asia (excluding China) and very little in the other two regions.
Of the some 760 million ha in agricultural use at present, only about 600 million ha are cropped and harvested in any given year. This is because land is being used at very different intensities in the different regions and agroecological zones. Thus, it is estimated that only about 55 percent of the land in regular crop production is cropped and harvested in any given year in sub-Saharan Africa (the rest being fallow), while the average cropping intensity is about 110 percent in South Asia, reflecting mainly the multiple cropping in the region's substantial areas under irrigation as well as the region's more general land scarcity. It is foreseen that the land needs for crop production growth will come in part from further increases in cropping intensities, and the average for the developing countries as a whole could rise from 79 percent at present to 85 percent in the year 2010. Thus, land cropped and harvested in an average year would increase from 600 million ha at present to about 720 million ha in year 2010, or 120 million ha increase compared with the 90 million ha of new land to be brought into crop production.
Achievement of the increased intensities and higher yields depends crucially on maintenance of irrigation and its further expansion by 23 million ha or 19 percent in a net sense, i.e. on top of the expansion needed to offset losses of irrigated land due to salinization, etc. This is a lower rate of expansion than in the past because of the well-known problems of increasing unit costs of irrigation investment and scarcity of water resources and suitable sites, as well as the enhanced attention paid to avoiding adverse environmental impacts. Given these constraints, but also for reasons of efficiency, the emphasis in the future will be more on making more efficient use of water and less on indiscriminate expansion of irrigated areas. The bulk of additional irrigation would be in South Asia, which now accounts for 52 percent of all irrigation of the developing countries (excluding China), a share it will maintain in the future. It is noted that the above-mentioned 23 million ha of additional irrigation is a net increment. In practice, the gross investment requirements for irrigation will have to cover a much wider area to account for rehabilitation of existing irrigated areas and to substitute for those permanently lost because of degradation.
Would agricultural expansion encroach on the forest?
The FAO Forest Resources Assessment 1990 produced data on the forest land of the tropical countries. Of the developing countries of the study for which the data on land with crop production potential were estimated, the forest area data are available for only 69 countries. The following comments examine the extent to which agricultural expansion may encroach on the forest. They, therefore, refer only to the subset of the 69 countries which account for all but 4 percent of the total tropical forest area in the FAO Forest Resources Assessment. They are also speculative because the extent of overlap between the forest and the land with agricultural potential is not fully known. Only some elements of such overlap can be deduced indirectly.
Subject to the data caveats, the situation in these 69 countries is one whereby 85 million ha are projected to be converted to agriculture in 20 years out of a total 1720 million ha of land with agricultural potential but not in crop production use at present. The extent to which this land overlaps with the forest area is not fully known, but a minimum estimate (derived as explained in Chapter 4) is about 800 million ha and the real overlap is probably much larger. Not much more can be said on this matter, except perhaps that if all the additional land for agriculture were to come from the forest areas, it would imply an annual rate of deforestation of 4.2 million ha, or 0.25 percent p.a. of the total forest area of these 69 countries of 1690 million ha. This compares with the 15 million ha (0.8 percent p.a.) of annual deforestation estimated for the 1980s. This latter figure, however, includes deforestation from all causes, not only from formal expansion of crop production. In particular, deforestation results from expansion of grazing (not included in the estimates of this study) and informal, unrecorded, agriculture using much more land than considered necessary to achieve the crop production increases. It also includes deforestation from logging of areas not yet reforested by natural regrowth and from fuelwood gathering operations. To the extent that expansion of grazing, informal agriculture, overcutting for fuelwood and unsustainable logging continue in the future it must be expected that deforestation will continue at a much greater rate than needed for expansion of formal agriculture.
Other claims on land
Land with agricultural potential is increasingly occupied by human settlements and infrastructure. Rough estimates for the developing countries (excluding China) indicate that such uses of land may be about 94 million ha, or 0.033 ha per caput (3000 persons/km2), but with this ratio varying widely among countries, depending on overall population densities. Not all human settlements are on land with agricultural potential, but about 50 million ha probably are in this category. With population growth, more land will be diverted to human settlements and infrastructure, though perhaps not in proportion, because with increasing population densities the land so used per person will tend to decline to perhaps 0.03 ha. This means that land in human settlements may increase to 128 million ha, of which perhaps some 70 million would be land with agricultural potential, an increase of the latter of 20 million ha. This potential use must therefore be added to that for the expansion of crop production proper, discussed above, to obtain an idea on future claims on the land with agricultural potential.
Further growth in fertilizer use and some in pesticide use in the developing countries
The developing countries (excluding China) use some 37 million tonnes of fertilizer (in terms of nutrients NPK). Such use increased four-fold in the last 20 years, though the growth rate of the 1980s was much lower than that of the 1970s. At present, the fertilizer use rates have reached 62 kg/ha of harvested area (about one-half the average of the developed countries), but with very wide differences, ranging regionally from 11 kg in sub-Saharan African to 90 kg in Near East/North Africa. The scope for further increases is much less than in the past. This, in combination with the lower rate of growth of agriculture, will tend to make for further declines in the growth rate of fertilizer consumption, to 3.8 percent p.a. in the period to 2010. Thus, projected fertilizer consumption in the developing countries (excluding China) may rise to some 80 million tonnes and the application rate to some 110 kg/ha. The environmental dimensions of this prospective development are discussed in Chapters 11-12. Here it is worth noting that while there are problems from excessive use in some irrigated areas of the developing countries, there are also problems from too little use in other areas, where it is associated with land degradation due to nutrient mining. Sub-Saharan Africa uses only 11 kg/ha. Even a doubling by 2010, as projected here, would still be too little for eliminating nutrient mining in some areas.
Traditional plant protection methods (tillage, burning, crop rotation) remain important in developing countries. However, methods based on the use of chemical pesticides have become widely used in recent decades. It is estimated that in the mid-1980s the developing countries accounted for about one-fifth of world consumption of pesticides (active ingredient). They account for about 50 percent of world use of insecticides, but for much smaller proportions of fungicides and herbicides. This reflects both agroecological and economic factors, e.g. higher incidence of insects in the humid tropics and cheaper labour for weed control. With labour costs rising in some countries, it can be expected that chemical herbicides will be used more widely.
The intensification of production and the expansion of agriculture into new areas in the developing countries could translate into further growth of pesticide use. Such growth could be contained at fairly low rates, through a combination of technological change, improved management and incentives and increasing resort to methods of integrated pest management (IPM). These prospects for the developing countries contrast with those for the developed countries where the lower growth of agriculture and the policies for pesticides as well as further spread of IPM could eventually lead to absolute declines in total use.
1.4 Further pressures on agricultural resources and the environment
The pressures for conversion to agricultural use and human settlements of land with agricultural potential were dealt with in the preceding section. On the whole such claims (110 million ha in all developing countries, excluding China) over the next 20 years would appear small when compared with about 1.8 billion ha of land with agricultural potential not occupied by either of the two uses. However, land scarcities are very acute in some countries and regions, viz. South Asia and Near East/North Africa. Even the small increases foreseen for them are a significant part of their still unused land. For example, the increments for these two uses would claim about 25 percent of the still unused land with agricultural potential in South Asia. There will be little land left for further expansion beyond the year 2010. It is noted that additional land for agriculture in South Asia will be needed even after allowing for further intensification. The latter could raise cropping intensities from 112 percent to 122 percent and double the fertilizer use rate per hectare.
Even though land constraints are severe in some countries and regions, those of freshwater supplies for agriculture are even more limiting for many more countries. The increasing claims on agricultural land for non-agricultural uses are minor when compared with those placed on water resources, because the per caput non-agricultural use of water tends to rise very rapidly with urbanization and industrialization. Competition between agriculture and the other sectors for dwindling per caput availabilities of freshwater will become more intense in the future and in most cases it can only be accommodated by increasing the efficiency in water use.
Degradation of soils is estimated to affect some 1.2 billion ha of land worldwide, of which about 450 million ha are in Asia. Among the causes, deforestation and overgrazing probably contribute one-third each, with the bulk of the balance due mostly to mismanagement of arable land. Soil (water and wind) erosion accounts for just over I billion ha of total degradation, with the balance due to chemical and physical degradation. Both man-made and natural processes (e.g. upward movements in the earth's crust) cause soil degradation. Some degradation will continue to occur in the future but the relationship between soil erosion and productivity loss is complex and more work is needed before firm conclusions can be drawn about the impact of soil erosion on yields.
Degradation from nutrient mining is a serious problem, particularly in the semi-arid areas of sub-Saharan Africa where livestock manure is in short supply and the use of mineral fertilizer is seldom economic. The problem will probably continue to exist over the next 20 years. Degradation from salinization of soils is primarily a problem of irrigated areas, but also occurs in hot dry zones. Available estimates of irrigated land losses from this cause vary widely while 10 15 percent of irrigated land is to some extent degraded through waterlogging and salinization.
Desertification (broadly: land degradation in dryland areas) is estimated to affect some 30 percent of the world's land surface. More recent thinking on desertification points to a growing consensus that the past estimates of area affected were greatly exaggerated. Some of the more extreme estimates were due to weaknesses in the methodology used to produce them. It is now recognized that drylands are much more resilient to drought and to man's abuse than previously thought. However, further expansion of agriculture into fragile soils in the dryland areas would contribute to increasing problems from this source.
Water contamination of agricultural origin (salt concentrations in irrigated areas, contamination from fertilizer and pesticides as well as from effluents of intensive livestock units and fish farms) will likely increase further because of the long length of time required for appropriate corrective action.
As regards pesticides, it is assumed that greater emphasis on integrated pest management and concerns about health and ecosystem conservation will tend to reduce the growth rate of pesticide use. But the more intensive use of land (reduced fallows, more multiple cropping) as well as the higher than average growth of the vegetables sector will contribute to further, though modest, increases in pesticide use in the developing countries.
Further expansion and intensification of agriculture will also contribute to intensified pressures on the environment of a global nature. Deforestation will affect adversely the dual role of forests as habitats for biodiversity and as major carbon sinks. Biodiversity will also likely suffer from possible further draining of wetlands for conversion to agriculture, even though this conversion may affect only a minor proportion of total wetlands. Additionally, agriculture will continue to contribute to the growth of greenhouse gases in the atmosphere (biomass burning in the process of deforestation, and methane emissions from rice cultivation and from ruminant livestock).
The eventual impacts of climate change are still uncertain, but on present evidence they may affect particularly adversely those regions already vulnerable to present-day climate variation, notably sub-Saharan Africa. The effects of an eventual rise in the sea level would also be severe for some countries and affect a good part of their high quality land resources. For the present and more immediate future, increased CO2 levels appear to have a positive effect on agriculture in general, because they contribute to higher yields through faster growth of plant biomass and better water utilization in many crops.
Existing and possible future technologies provide scope for responding, wholly or partially, to the increased pressures of agricultural origin on the environment. Exploring the potential for doing so requires shifting technology from "hardware" solutions requiring large inputs of fixed and variable capital, e.g. machine-made land terraces or pesticides, to solutions based on more sophisticated, knowledge and information-intensive resource management practices which can lower both off-farm costs and environmental pressures. This is not to suggest that a new technological approach is sufficient by itself. Much will depend on policies and institutional measures providing incentives needed for farmers, forest users and fishermen to adopt sustainable technologies and resource management practices. Institutional measures will include the establishment of well-defined property or user rights for public and private resources, as well as enhanced people's participation and decentralized resource management.
It is noted from the outset that the general debate regarding the merits of low or high external input technological development paths for agriculture has run its course, and there is growing acceptance that neither of the two approaches has the whole answer. What is required is a balanced integration of the two systems. For example, the use of mineral fertilizer will continue to grow but it cannot in many situations provide all the inputs necessary to maintain soil fertility and must be associated with organic manures and other biological inputs as part of an integrated plant nutrition system (IPNS).
More generally, the extent to which countries will follow more environment friendly practices depends on their socioeconomic and natural resource situations. The developed countries are in a better position to do so, and are moving in this direction. In contrast, the developing countries are in much greater need to improve the management of their agricultural resources because their livelihoods depend crucially on them. At the same time, however, they are in greater need than the developed countries to increase production through intensification and have much less access to technologies and resources for more sustainable production. But there is much scope for improvement and for minimizing trade-offs between more production and the environment even under these unfavourable conditions. The important thing is for policies to recognize that the first priority of many farmers is household food security and family welfare. Thus efforts to minimize trade-offs between more production and the environment must be centred on actions that improve household food security and are profitable on time scales which meet the farmers' differing circumstances or risk perceptions.
It is now well recognized that the past heavy dependence of the agricultural development of the developing countries on the transfer of technologies and management practices of the developed countries contributed to raise production and productivity, but it had some undesirable effects, e.g. discouragement of mixed cropping and minimal tillage practices, dominance of mineral fertilizer, emphasis on engineering rather than biological approaches to soil stabilization, neglect of semi-arid areas and crops, etc. Corrective action would require a shift in national and international research priorities, with particular emphasis on technologies which are not too risky and are profitable at early stages in the adoption process. Efforts to build on indigenous technical knowledge hold promise, but there is no guarantee that they will be sufficient in isolation.
In the quest for limiting land and water degradation, the wider adoption of known techniques of soil conservation with low external capital requirements could help boost or stabilize yields in the first half of the projection period. Dryland areas in sub-Saharan Africa and Asia could benefit from such techniques, as would slopelands in the humid tropics. Likewise, efforts for dealing with the salinization problem could benefit from integration of the standard corrective action (drainage, canal lining) with a more holistic approach to water management, e.g. conjunctive use of surface and groundwater and parallel use of canal and tubewell systems. More generally, the increasing dependence on raising water use efficiency for coping with the growing water shortages will require some radical rethinking of policy approaches to pricing water and to needed institutional changes.
Wider adoption of integrated plant nutrition, its further development and improved management of input use provide the main technological way to meeting the challenge of required increases in nutrient supplies in support of more production while minimizing adverse effects on the environment. Likewise, integrated pest management is to be the mainstay of efforts- in the plant protection area, with priority to the crops accounting for the bulk of pesticide use: cotton, maize, soybeans, fruit and vegetables.
In the livestock sector, there is much in the technological pipeline to meet the challenge of moving towards more sustainable production systems. Policies in this direction could have an impact well before 2010. The aims would be to compensate for the lack or poor quality of land through measures to raise pasture and rangeland output and improve management systems; to bring about a closer integration of crop and livestock production; to raise the supply and quality of supplementary feeds; to achieve genetic improvements from conventional breeding and modern biotechnical tools; and to complement these gains with cheaper and more effective animal health measures.
Biotechnology offers a range of applications for plant and animal production. Some are likely to have an increasing impact well before 2010; others in the longer term. The former include tissue culture of virus-free stocks of cassava and other root crops, and the introduction of microbial plant growth promoters, e.g. mycorrhiza. The latter include cereals with the ability to fix some of their own nitrogen needs, and transgenic tree crops.
Making progress towards the adoption of technologies for sustainable agriculture will depend greatly on increased agricultural research efforts with emphasis on: (a) improved management of biological systems, based on a better understanding of their feedback and balancing processes; (b) better information management, implying the need for sound data on natural resources, land use and farming systems, etc., to improve environmental monitoring capability; and (c) better farm-household system management, in order to obtain a better integration of activities in the household and in the field, and on and off the farm. At the operational level, the research effort should be directed at promoting sustainable increases in productivity in the higher potential areas as well as at targeting marginal and fragile environments where current degradation must be reversed and production stabilized or raised. These thrusts must be supplemented by two cross-cutting and highly complementary approaches, that of rehabilitation and restoration of ecology, and that of exploiting the synergism of indigenous technical knowledge and modern science. All four actions must be supported by international efforts to strengthen the national agricultural research systems, both institutionally and financially.
Finally, international agricultural trade and policies affecting it can exert influences on the environment and the prospects for sustainable development. Trade may affect the environment if production shifts from places where it is less sustainable to places where it is more sustainable and vice versa. To the extent that trade contributes to shift production to more sustainable locations, more trade would tend to lower global pressures on resources and the environment. Such pressures would be minimized when all trading countries have environmental policies which embody the environmental externalities into the costs of production and the prices of the traded goods. However, environmental externalities need not be valued in the same way in countries with differing resource endowments and levels of development. In particular poor countries should not be denied opportunities for profitable trade because they do not meet the strict, and often inappropriate for them, environmental conditions reflecting values of much wealthier societies.
With the exception of fuelwood, per caput consumption of forest and forest industry products will continue to grow, particularly in the developing countries, with growth being highest for wood-based panels and paper. The developed countries as a whole should face no major problem in increasing production of wood in sustainable ways by as much as required for their own consumption and exports. The developing countries depend currently to a high degree on natural forests for the production of wood, for own consumption and exports. Such dependence and their higher growth of demand will make it more difficult for them to increase production in sustainable ways, unless greatly improved management measures are instituted and forest plantations greatly expanded.
Developing countries, particularly the poorest ones, depend on wood for a major part of their energy supplies. The shortages of fuelwood are likely to persist and become more acute as accessible forest and non-forest sources dwindle due to overexploitation and conversion of forest land to other uses. Although much of the growth in energy consumption of the population groups which depend on fuelwood will be met by the continuing trend towards substitution of alternative fuels for wood, some population groups (e.g. the urban poor or rural people in remote locations) are not likely to have ready access to such alternatives. For them, the future outlook is for more work to be put into procuring wood and making do with less energy.
Pressures on the forest for meeting often conflicting demands are bound to increase, mainly in the developing countries, and continue to imperil the forest's essential environmental functions. The highest risk is manifested in terms of tropical deforestation. It continued to advance in the 1980s at about 15 million ha p.a., or 0.8 percent of the total tropical forest area. The FAO Forest Resources Assessment 1990 documents that deforestation is observed to radiate out from the populated areas and that the higher the increase in population densities the higher the rate of deforestation, other things being equal. It also notes that much of the deforestation is related to the expansion of agriculture, whether in the form of recorded conversion to arable land or, more often, unrecorded expansion. Fuelwood collection is also a contributing factor. Logging per se, on the other hand, need not lead to permanent loss of forest if soundly managed. It may, however, affect other vital environmental functions of the forest, e.g. biodiversity. Moreover, the opening-up of previously inaccessible forest areas by logging operations tends to facilitate settlement and conversion to agriculture.
These findings seem to confirm the common belief that there is a close association between population growth and deforestation. However, for policy purposes the mechanism connecting these two variables has to be understood. This is no simple matter, for the reasons discussed earlier in relation to the build-up of pressures on agricultural resources and the environment. In particular, it is noted that the most relevant aspect of population growth is the extent to which it is associated with increases in the number of people depending on agriculture, and more generally the rural poor. Many developing countries are far from having reached the stage when pressures from this kind of population growth are relaxed. Some of them are not even making progress towards it.
It follows that further deforestation is to be expected in the future. Some speculative comments on the possible deforestation impact of expansion of agriculture and human settlements for the year 2010 were made in Section 1.4. It was noted there that informal and disorderly expansion of agriculture may lead to a higher rate of conversion of land and forest areas than required by the projected growth in crop production. Expansion of grazing, fuelwood production and unsustainable logging may further contribute to deforestation. Under the circumstances, the key issue is how to minimize loss of forest during this rather protracted, though hopefully transitory, phase, until such time as the inherent forces (development, reduction in agricultural population and rural poverty, etc.) making for containment or reversal of deforestation come into play.
The preceding discussion is based on two premisses: (a) that much of the deforestation is caused by expansion of agriculture, and (b) that it is closely related to the growth of population in poverty, and indeed that part which depends on agriculture for a living. True as these premisses are, they tell only part of the story. In particular it may not be concluded that the rate of damage to the forest will slow down at the initial stage of accelerated economic growth and poverty reduction. There is evidence suggesting that the opposite may happen. This is explained in part by the fact that more intensified exploitation of forest resources and expansion of agriculture to exploit profitable opportunities are part and parcel of the very process of accelerated development and poverty reduction. In practice, countries tend to run down their natural capital to increase incomes as conventionally measured, i.e. without netting-out the income gains for the losses of natural capital. The other contributing factor has to do with the limited capabilities of countries to formulate and enforce rules for sustainable exploitation of the forest resources; and in some cases their own sector-specific or economy-wide policies translate into incentives for unsustainable exploitation. Ignoring other causes of deforestation, in particular the complex interactions of activities by both the poor and the non-poor, can lead to wrong policy conclusions as noted earlier.
1.7 Increasing resource constraints in fisheries
The historical developments as well as the future prospects of the fisheries sector are conditioned, to a significant extent, by the wild characteristic of the resource and the fact that, for most species, the levels of production are limited by nature. This has three important consequences. First, beyond certain levels, additional investment in fishing effort does not produce additional yields and, in many cases, actually leads to declines in total catch as well as to economic waste. Such an increase in fishing effort is inevitable in those, almost universal, situations where there is ineffective fisheries management. Second, with growing demand and limited supplies, the real prices of fish products inevitably increase. This has important and damaging consequences for low-income consumers, particularly those in the developing countries. The third major, and more positive, result is that limited natural supplies and high prices serve to stimulate increased production through the cultivation of those species that allow it.
World production of fish had been increasing up to 1989 to a peak of 100 million tonnes after which it declined to about 97 million tonnes in the three subsequent years. The share of culture fisheries in total production has been increasing rapidly and it currently accounts for about 12 percent of the total. Marine capture fisheries account for about 80 million tonnes of the total. It is now evident that the yield of this sector is adversely affected at extraction levels beyond about 80 million tonnes.
The natural resource constraints to increasing production in the capture fisheries sector mean that additional fishing effort and investment is unlikely to increase production and may well lead to declines. Better management and other interventions which would favour recovery of fish stocks could make it possible to increase somewhat capture fisheries production (marine and inland) from the present 85 million tonnes to perhaps 90 110 million tonnes. This estimate is hypothetical and subject to many uncertainties. Culture fisheries (marine and inland) have higher growth potential, but even here constraints are present (technology, environment, disease). There is scope for reducing these constraints, particularly for marine environment aquaculture, and it is possible that production could grow at a higher rate than that of capture fisheries, e.g. from 12 million tonnes to 15-20 million tonnes by year 2010.
It follows that total fish production from all sources could be in year 2010 between 10 and 30 percent above present levels. Over the same period, world population is expected to grow by 36 percent. Therefore, per caput fish supplies will likely fall. Consumption by the poor may fall by more and shift in part to species currently used for reduction to fishmeal, as the species currently less preferred by high-income consumers are diverted to their segment of the market. These prospective developments can have serious nutritional consequences for the poor consumers in countries with high dependence on fish for protein supplies, e.g. many countries in Asia and Africa.
The increasing supply constraints and the associated rise in the real price of fish will tend to stimulate greater investment in fishing effort, thus establishing a vicious circle whereby stock depletion reduces supplies leading to additional price increases. This process has been aided by heavy subsidies granted to fisheries by major countries. With the reforms under way in the ax-centrally planned economies of Europe, a substantial part of their subsidized operations has become openly uneconomic. The consequent reductions in the fleets of these countries are leading to significant structural change in the world fishing industry.
This vicious circle can partly be broken by the establishment of systems of exclusive use rights which provide the fishermen with a stake in the resource and an interest in future returns. However, as many governments have found, this is difficult to achieve. At national levels, fishery administrators generally do not have the mandate to make such decisions. In international areas or areas where stocks are shared by countries (e.g. the northeast Atlantic), negotiators cannot readily agree to controls which limit the rights of their own fishermen. But as the problems become increasingly severe, the issues are raised to higher political levels and, eventually, will force the necessary decisions. Several countries have already taken the basic steps to create exclusive use rights and have achieved significant benefits. Although the systems still contain many imperfections, the improvements that have been produced provide valuable lessons for other countries. There is some hope, therefore, that the management of fisheries will eventually improve. However, although the benefits will be significant in reducing biological and economic waste, they will still not be sufficient to overcome the limits on supply.
Finally, fisheries and more general policies must address the problems increasingly affecting small-scale fisheries: conflict with large-scale operations in the inshore waters and degradation of the coastal environment. This is necessary for social purposes, for shifting production on to a more sustainable base and for minimizing adverse effects on the environment. With regard to the latter, it is noted that the coastal zone receives large amounts of pollutants including: organic wastes from municipalities, chemical wastes from industries, pesticides and herbicides from agriculture and siltation from forest land clearing and road building. In addition, activities within the coastal zone also affect the environment. These include mining of coral reefs and destruction of mangrove swamps. Fishermen themselves contribute to these kinds of damage by converting mangrove swamps to mariculture ponds for shrimp; by excessive use of feed and antibiotics in cage culture; and by using dynamite, poison and other kinds of techniques that destroy coral reefs.