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Rehabilitation of riverine habitat for fisheries1


Human activities have left their mark on streams and rivers for thousands of years. As a consequence of industrialization and human population growth, pressure on natural watercourses and their aquatic habitats has intensified through history and the degradation of aquatic habitats has accelerated – with negative consequences for aquatic species and therefore also for fisheries. Currently, nearly all watercourses in developed countries have been adversely affected by development to various degrees and inland water habitats in many developing countries are following the same route.

However, the situation is gradually changing and many developed countries are trying to reverse these longstanding negative impacts through rehabilitation of riverine habitats. the international community, including FAO, through the Code of Conduct for responsible Fisheries,2 has acknowledged the value of understanding ecosystem processes – the biological, physical and chemical qualities of aquatic habitats; habitat protection and rehabilitation; nutrient cycling; and the interactions of non-target species – in maintaining the productivity of fisheries. the Code thus recognizes the need to conserve and rehabilitate habitats cost-effectively through an ecosystem approach. According to the Code’s technical guidelines for inland fisheries: “States should clearly formulate national plans for the use of water including allocation for fisheries and for the protection of the aquatic environment”.3

Unfortunately, there have been only a limited number of good studies of habitat rehabilitation and monitoring on which to base advice, especially for developing countries. Although the studies reviewed provide technical information on rehabilitation projects from various parts of the world, most were undertaken in temperate countries, and modifications of the methods and strategies used there may be necessary before they can be adapted to other riverine habitats. Another concern is that many studies on the effectiveness of habitat rehabilitation have analysed the physical–chemical parameters of the water, i.e. the water quality, rather than the increase in fish production.


Restoration of riverine habitats to pristine conditions is generally not practical; it is usually only realistic to aim at rehabilitating key functions in the ecosystem through the rehabilitation or re-creation of functional habitats and the establishment of connectivity between them. Where habitats have been degraded and fish production has decreased as a result, rehabilitation efforts should be preceded by assessments of what has happened to the aquatic ecosystem, i.e. what functions have been lost or degraded. the goal of such assessments is both to identify the impacts on specific areas of the ecosystem or on key ecosystem processes that affect stream habitats, and to specify management actions required to restore or rehabilitate those processes that sustain aquatic habitats and support fish production (table 13).

Restoring specific fish populations is subordinate to the goal of restoring the ecosystem that supports multiple species. As long as all rehabilitation actions are consistent with the overriding goal of restoring ecosystem processes and functions, habitats will be restored for multiple species.

Many conflicting uses, and thus social and economic interests, are at stake in inland waters. Indeed, the requirements for the maintenance of healthy stocks of fish and other living aquatic resources and the fisheries that depend on them are frequently of secondary importance to other considerations. therefore, the costs and benefits of maintaining or restoring inland fisheries need to be balanced against the costs and benefits of other uses of the water. Moreover, it should be recognized that the costs of all alternative uses of inland waters comprise not only actual expenses incurred, but may also include losses of future opportunities. It should also be recognized, when estimating the costs of maintaining healthy fish stocks, that there are alternative approaches to protection, mitigation and rehabilitation.

Table 13
Specific conditions of aquatic habitats important for the rehabilitation of fisheries

General category


Water flow

Minimum acceptable flow
Timing of flow
Speed of change in discharge or water level

Habitat connectivity

Maintenance of access to critical habitats (longitudinal; lateral)
Removal of obstructions to fish movement or mitigation (e.g. fish passage facilities)
Maintenance of access to inflowing tributaries in lakes
Connectivity to lateral marshes, floodplains, etc.

Habitat diversity

Maintenance of and access to critical habitats
Provision for adequate diversity in main waterbody 
Maintenance of riparian vegetation structure

Water quality

Avoidance of chronic or acute, diffuse or point source pollution by toxic substances 
Regulation of nutrients with critical limits

Physical disturbance

Limitation of boat wash road and other development 
Limitation of forest and plant removal and on weed cutting 
Limitation of grazing or other disturbance

Basin characteristics

Land-use practice to avoid erosion and uncontrolled runoff 
Avoidance of inappropriate types of vegetation cover 
Connectivity buffer zones

Source: Adapted from R.L. Welcomme. 2001. Inland fisheries: ecology and management. Oxford, UK, Fishing News Books.

Benefits from rehabilitation include not only the income that can be generated from fishing, but also ecosystem services such as nutrient cycling, sediment transport and carbon sequestering, as well as less tangible benefits such as those relating to the aesthetic and conservation aspects of an intact ecosystem. Because cost–benefit calculations may favour non-fisheries use in the short term, it is important to consider the time horizon taken into accunt in the analysis. the time horizon should be long enough to allow the short-term result to be balanced with the long-term interests and values inherent in the ecosystem. this applies not only to new projects for the use of freshwater but also to existing ones. Neglecting an already degraded environment will only delay – and possibly increase – the bill for rehabilitation.

A multidisciplinary basin-wide approach that includes land and water management is needed if rehabilitation is to be achieved sustainably. Fisheries managers, and those responsible for conserving the environment, must negotiate the best possible conditions for the maintenance of fish stocks and fisheries. However, the economic interests of other sectors, for example power generation, navigation, agriculture and industry, are difficult to counterbalance because it is not easy to provide well-documented and accurate figures that demonstrate the economic value of the intact aquatic habitat and its associated fish populations and biodiversity. In this process, it is the task of fisheries managers and those responsible for conserving the environment to negotiate the best possible conditions for maintaining the fish stocks and fisheries. Where politicians have defined an enabling framework, tensions among the various stakeholders can be reduced and larger benefits derived from the many goods and services the aquatic ecosystems supply, including products for human consumption.

Decision-makers may choose from management schemes ranging from “do nothing”, when the costs involved with rehabilitation are unacceptable, to “provide mitigation and rehabilitation”, or to “provide total protection” with the establishment of sanctuaries in which no activities are allowed in the watershed.


Rehabilitation of rivers should focus on creating structural diversity (depth, flow, substrate and riparian structures) and re-establishing longitudinal and lateral connectivity (table 14). At the same time, it should aim to create conditions that favour communities of species. Many rehabilitation measures are currently guided by the principle of the “potentially natural species composition”, where not only existing species are considered as targets of rehabilitation, but also species that had lived there in the past and might one day return/be brought back. the habitat characteristics requiring improvement must be identified accordingly, including all functional units used by fish and especially during sensitive stages of the fishes’ lifecycles. However, the final rehabilitation strategy must be sufficiently flexible to allow new knowledge and tools to be incorporated.

The level of knowledge concerning species and ecosystems associated with inland waters is variable and patchy on a global scale. relatively simple and species-poor systems, such as temperate salmonid streams, are relatively well understood, while the much more complex large tropical rivers are less well studied and only poorly understood. It is therefore frequently necessary to work with models that require only limited knowledge of the biology of individual species, but focus more on the restoration of ecosystem functions and processes. Detailed planning for the conservation of specific species requires more complete knowledge of the biology and the behaviour of the species involved.

Table 14
Common categories of habitat rehabilitation and examples of common actions

General category


Typical goals

Road improvements

Removal or abandonment
Addition or removal of culverts

Reduce sediment supply 
Restore hydology 
Improve water quality

Riparian restoration

Fencing to exclude livestock 
Removal of grazing 
Planting of trees and vegetation 
Thinning or removal of underbrush 
and bushes

Restore riparian vegetation and
Provide shade and shelter
Improve bank stability and instream

Floodplain connectivity

Levee removal
Reconnection of sloughs, lakes 
Excavation of new floodplain 

Reconnect lateral habitats
Allow the river channel freedom to
meander and shift its course

Dam removal and flow modification

Removal or breaching of dam 
Increase in instream flows 
Restoration of natural flood regime

Reconnect migration corridors 
Allow natural transport of sediment 
and nutrients

Instream structures

Placement of log or boulder 
Engineered log jams 
Placement of spawning gravel 
Placement of brush or other cover Re-meandering a straightened stream

Improve instream habitat conditions 
for fish

Nutrient enrichment

Addition of organic and inorganic nutrients

Boost productivity of system to 
improve biotic production 
Compensate for reduced nutrient 
levels from lack of ana dromous fishes

rehabilitation techniqu

Reintroduction or removal of beavers
Brush removal
Bank protection
Habitat protection through land
acquisition, conservation, easements
or legal protection (laws)
Instream flows

Reduce or increase habitat
Prevent erosion or channel migration
Protect habitat from further
Provide adequate flows for aquatic
biota and habitat

Structural diversity

Fish abundance may be increased locally in the short to medium term. It has been demonstrated that the improvement of habitats through enhancing structural diversity – by adding instream structures such as logs or boulders or by creating pools and riffles that serve to oxygenate the water, trap sediments and provide shelter – increases fish abundance locally in the short to medium term. However, because this ften does not address the underlying causes of habitat degradation, a more permanent solution requires large changes that restore or mimic natural processes.

Many rivers and streams have been canalized, for navigation purposes or in order to carry away water more efficiently. In this situation habitat complexity may be increased through decanalization and by restoring meanders and reconstructing floodplain habitats. this will increase the length of the streams and lead to physical and biotic changes that will benefit fish and invertebrates. However, such large-scale projects are relatively recent and there has not yet been enough time to evaluate the results properly.

Restoration of processes

Important elements in restoring the ecosystem processes are the linkages between aquatic and terrestrial ecosystems. A few studies indicate that in areas with degraded riparian habitat where there is no tree cover on the banks, water temperatures, for example, tend to be higher and fish abundance lower than in areas where the vegetation is intact. riparian vegetation is also important in providing shade, shelter, nutrients, woody debris and food for fishes. replanting and protection to exclude cattle and other grazers of riparian vegetation have proved effective as a means for restoring fish populations in some areas.

Restoration of floods

Floods are necessary for a variety of ecological processes and associated species of plants, trees, animals, fishes and birds. Where the natural flood pattern cannot be fully restored it may still be possible to restore partially key features of the flood cycle. Important elements in the flood cycle include timing, amplitude, duration, rapidity, smoothness and upstream drawdown level. Managers of dams and hydroelectric plants should be encouraged to time the release of their water in accordance with natural flood cycles to enable rehabilitation of fisheries that are dependent on floods.

Longitudinal connectivity

Rehabilitation of river fisheries depends on the longitudinal exchange of fish, nutrients, sediments, organic matter and water in sufficient quantity and quality. rehabilitation strategies often include small-scale interventions that are easy to implement but may have limited long-term impact. For example, because of the decrease of anadromous fish species, some streams currently have only 6–7 percent of their historic nitrogen and phosphorus levels. In such situations, nutrient flows along the river have been augmented with salmon carcasses or inorganic nutrients, resulting in some increases in juvenile salmon and macro invertebrate abundance.

However, more serious rehabilitation projects should involve longer-term strategies that address fish movements, water flow, land-use planning and water-resource management for the entire catchment level or river basin.

Migratory fishes are often the most valuable commercially, but are among the first to disappear when water becomes polluted or when migration routes are interrupted by physical structures. Migratory species are therefore often used as indicators of ecological health. However, it is not only the long-distance migratory species that suffer from habitat fragmentation but all species that during their lifecycle depend on longitudinal movements.

When improving migration conditions for fish, it is important to look at all life stages as their requirements might be quite different (e.g. upstream migration of small young eels; downstream migration of large adult eels). Passage mitigation structures should thus be designed according to the needs and abilities of the different species and the different life stages of those species. For example, the design of sluices that regulate the flow of water in and out of poldered areas will determine whether pelagic fish eggs, bottom-living juveniles or adult fishes are able to enter the area.

When mgration routes have been blocked by dams, the best solution for fisheries is to remove the dam in order to ensure both upstream and downstream passage. Dams have a limited operating life (around 50 years) and are costly to maintain. In the United States of America, approximately 500, mostly small, dams have been removed during the past 20 years. Apart from allowing fish movement both upstream and downstream, removal is also highly effective at restoring processes that have been disrupted as a result of damming, such as nutrient cycling and transport of nutrients and sediments.

Fish passes, which facilitate the movement of fish past blocking structures, have commonly been used to restore fish migration. When fish passes are incorporated into the early design of a dam construction project, their costs are equivalent to only a small percentage of the total costs. But if fish passes have to be fitted retroactively, costs increase drastically. If dam construction cannot be avoided, it is thus the responsibility of fisheries managers at least to ensure that the appropriate types of fish passes are planned at the earliest stages of the project. It is also important to choose the fish pass design that matches most closely the behaviour and requirements of the species present (or likely to be present at a later stage). Fish passes designed for salmonids, for example, should not be used blindly if non-salmonid species are the target group, because these passes might be ineffective or less effective for species with swimming abilities different from those of salmon. If little is known about the requirements of the species present, the most versatile fish pass design should be chosen, which in many cases would be the vertical slot pass (Figure 37).


Lateral connectivity

Lateral connectivity of habitats to the main river channel is also essential for many fisheries. Lowland rivers with floodplains are often contained by massive levee systems erected to protect cropland, settlements and other infrastructure against floods. the result of such development is that the floodplains become isolated from the rivers, and the seasonal dynamics of the system are eliminated, with negative consequences for the fisheries.

Heavy anthropogenic modifications (e.g. densely populated areas along rivers), and the resulting social and economic costs involved in removing levees, mean that this rehabilitation method is not always feasible. However, dikes can be set back to allow a partial flooding of the former floodplain. In certain areas the river may also be allowed to inundate the entire floodplain. By re-allowing the fish to enter flooded areas to spawn and feed, the large surplus production of juvenile fishes, which is characteristic of healthy floodplains, ensures adequate recruitment of fish to restore fish populations.

Isolated waterbodies such as side channels, oxbow lakes and floodplain pools may be linked through the installation or improvement of culverts or through the creation of natural channels. these are good options because they rely on already existing habitats that only need Reconnection. When such natural habitats are absent they can be replaced by human-made waterbodies such as gravel extraction sites or borrow pits, which can be engineered to favour species diversity.


The studies reviewed in this section clearly indicate that riverine habitat rehabilitation should be based on an ecosystem approach in which key processes are re-established and maintained. In this way rehabilitation will benefit a number of aquatic species and therefore help improve inland fisheries. to ensure the maximum efficiency of remedial measures, the ecological requirements of all riverine species during all their life stages (particularly those of migrants) must be taken into consideration from the earliest planning stages. the watershed, or basin, provides a geographic setting: the entire basin should be considered, as no reabilitation project can be considered in isolation from its basin and the people who live there. Activities upstream can counteract any effort made at the local level.

Inland fisheries are most seriously affected by factors external to the fishery sector. Social, economic and institutional issues, and competing uses of inland waters, often impede the application of technologies to rehabilitate rivers for fisheries. Major interventions (re-meandering, floodplain restoration or removal of dams) are costly and require the active cooperation of riparian landowners and other stakeholders, or the acquisition of the land by the state. Although the cost-effectiveness of rehabilitation projects has seldom been studied, it is clear that habitat protection is the most cost-effective means for maintaining riverine fisheries.

Knowledge of inland waters, including their aquatic biodiversity and fisheries, remains partial in many parts of the world and few habitat rehabilitation projects have been adequately evaluated. Although further research and information are clearly desirable, the rehabilitation methods reviewed above do show promise, and our existing knowledge of ecosystem functions, ecosystem processes and the requirements of aquatic species should allow us to act now to rehabilitate many important fisheries if the political will is strong enough.

Responsible fish trade and food security


Since ancient times, fish from the oceans and other aquatic bodies have been an important source of food. However, those who specialize in harvesting fish cannot consume all the fish caught. Even at low levels of productivity, there is a need to barter or exchange the surplus. trading, even locally and domestically, is more innate to a fishery than it is to livestock or agriculture.

A major component of global trade has long been food products such as spices, grains, salt, fruits, sugar, meat and fish. the global food trade has bridged vast distances and cultures. today, fish is being transported to the market from all over the world. the biggest fish market in the world, Tsukiji Fish Market in Tokyo, is a good example – fresh fish from all the world’s oceans are on display there.

Trade in fish products connects producers with consumers and contributes to food security and higher living standards. For some time, observers of fish trade have been debating whether or not this is true for all those involved in and/or linked with trade in fish and fish products. In these debates, concerns relating to fish and food security have tended to focus directly on fish for consumption. Consequently, when fish exports have been examined, the focus has been primarily on how they reduce the availability of fish for domestic consumption; fish imports, on the other hand, have been seen mostly as a means of increasing local food-fish availability. In fact, the relationship between trade (exports and imports) and food security is more complex. Production for export can enhance the incomes of poor fishers substantially and thus raise their trade-based entitlements, enabling them to achieve greater food security.

In order to understand how, when and where trade in fishery products contributes to, and/or detracts from, food security, FAO and the Norwegian Agency for International Development (NORAD) commissioned a global study consisting of assessment studies in 11 countries: Brazil, Chile, Fiji, Ghana, Kenya, Namibia, Nicaragua, the Philippines, Senegal, Sri Lanka and Thailand.4 the countries were selected as examples of countries actively involved in international fish trade and to ensure a wide geographical spread. Moreover, these countries have seen a rapid increase in their fish exports over the past 10 to 20 years.

The study addressed the trade issue from a broader perspective than has been the practice in much of the recent debate. It focused primarily on the direct and indirec influence of fish trade on food security and reviewed in detail the positive and negative impacts of international fish trade on food security in LIFDCs. Figure 38 illustrates schematically how the direct and indirect influences of fish trade were evaluated.


The study’s main conclusion was that international trade in fishery products has had a positive effect on food security in the developing countries participating in such trade.

International fish trade has increased dramatically over the past 20 years, from US$15.4 billion in 1980 to US$71.5 billion in 2004. Developing countries have particularly benefited from this increase, with their net receipts increasing from US$3.7 billion to US$20.4 billion over the same period. this was greater than their net exports of other food commodities such as coffee, bananas, rice and tea taken together.

There is, however, room for improvement. trade statistics indicate no significant change in the composition of exports from developing countries over the past decades. Most exported fish products are frozen. While in some instances this is because of the nature of the product being exported, there is also some evidence that tariff escalation in developed countries has prevented the growth of an export trade in value-added fish products from developing countries.

Production and trade statistics also indicate that international trade has not had a detrimental effect on the availability of fish as food. Increases in production, coupled with import and export of fishery products, have ensured continued availability of fish for the domestic markets in LIFDCs. Moreover, proceeds from fish exports are also used to import other foods, including fish products.

In all the countries studied, the number of people employed in export-oriented fisheries had increased over time. Significant new employment had been created in fish-processing activities as a result of international trade. At the time of the study, the total number of employees in fish-processing activities varied according to the size of the trade operations – from 900 in Kenya to 212 000 in Thailand.

In eight of the 11 countries studied, international trade had had a positive impact on food security.5 this conclusion was based on outcomes related to the national economy and on impacts on fishers, fish workers and fish consumers.


Additionally, fish exports were among the top ten foreign-exchange earners in eight of the countries – Chile, Fiji, Ghana, Kenya, Namibia, Nicaragua, Senegal and thailand. Without doubt, in LIFDCs the earnings from international trade in fishery products contribute to ensuring food security at the aggregate level.

Thailand, one of the world’s largest fish-exporting countries, has seen a considerable increase in rural incomes as a result of the overall export orientation of the economy. Fishers are likely to have benefited to the extent that their harvesting and production were linked to export-oriented species. Poverty levels in the rural areas have also dropped significantly.

Modern international trade also has consequences for the lives of the traditional fish processors, the vast majority of whom are women – generally middle-aged and with little education. Any change in the trade policy of a country has an impact on women fish workers. this has important bearings on the question of food security and poverty. On the one hand, as numerous studies have shown, an increase in the income of women, as opposed to men, has a greater positive impact on household food security. Expanding fish-processing activities in developing countries, including those generating additional value to fish destined for export markets, has created new jobs among women, mainly young women. On the other hand, increased exports of fishery products, particularly to developed countries, has led to a significat decline in the quantity, and also an increase in the price, of fish available to women involved in traditional fish processing. this has resulted in some loss of employment, income or both.

The study found that international trade in food products generally has a negative impact on fish resources. Clearly, there is an urgent need for more effective and sustainable resource-management practices, without which there can be no sustainable international trade. Preserving the resource base and the integrity of the aquatic ecosystem is a sine qua non for food security – with or without international trade. the fundamental requirement is to sustain the growth of fish production and maintain a harmonious balance between the three realms – marine capture, inland capture and aquaculture – in accordance with the social and physical context. In aquaculture, achieving a new balance between intensive and extensive production techniques, including more efficient feed-conversion ratios and the search for non-animal protein feeds, should be a priority.

The study also highlights the need for free and transparent trade and market policies. these will help ensure that the benefits accruing from international fish trade are shared by all segments of society. In this respect, the study underscores the recommendation of FAO’s Code of Conduct for responsible Fisheries that states consult with all stakeholders, industry as well as consumer and environmental groups, in the development of laws and regulations related to trade in fish and fishery products.

Finally the study recommended the following targets for countries, particularly developing countries, aiming to increase food security through international fish trade:

  1. better fishery resource management;
  2. better information on the chain of custody and trade structure;
  3. recognition of subsistence fishing as a major source of direct food security;
  4. more social security for fish workers;
  5. improved livelihood-related infrastructure, such as housing, sanitation and water supply;
  6. better coordination in data and statistics collection;
  7. assistance for developing countries in adapting to new market conditions;
  8. better regional cooperation among developing countries;
  9. more inclusive and responsible fish trade;
  10. responsible fish consumption in developed countries.

Trash or treasure? Low-value/trash fish from marine fisheries in the Asia–Pacific region6


Marine fishery products from both capture and culture continue to play a significant role in the food security, poverty alleviation and economies of many countries in the Asia–Pacific region. Over the past 20 years, major changes have occurred in these fisheries – overexploitation of marine coastal fishery resources has led to the encouragement of coastal aquaculture to meet the growing demand for seafood, income, employment and export earnings in many countries.

The shift to aquaculture to make up for reduced capture supply and quality may not have factored in the close link between capture fisheries and aquaculture. this is particularly the case where aquaculture depends on the capture fishery to provide its feed, either directly as fresh fish or through fishmeal and fish oil. Fishing and aquaculture have become lockd into a loop (see Figure 39), where the demand for low-value/trash fish for fish and animal feeds supports increased fishing pressure on already degraded resources. this raises some important questions regarding the social, economic and ecological costs and benefits of this system, its sustainability and future trends.

Box 12

Low-value/trash fish: a definition

For the purpose of this article we define low-value/trash fish as: Fish that have a low commercial value by virtue of their low quality, small size or low consumer preference. they are either used for human consumption (often processed or preserved) or fed to livestock/fish, either directly, or through reduction to fishmeal/oil.

Note that in China and thailand the term only applies to fsh used as livestock/fsh feed.


In many coastal demersal fisheries in Asia, “fishing down the food chain”7 has resulted in an increase in the percentage of low-value/trash fish, especially in heavily fished areas in China, Tailand and Viet Nam. the Asia-Pacific Fishery Commission (APFIC) has provided initial estimates for six major fish-producing countries in the region (table 15). A weighted average8 of low-value/trash fish across the six countries amounts to 25 percent of the total marine catch, with estimates greater than 50 percent in specific fisheries.


Table 15
Estimations of annual low-value/trash-fish production in the Asia–Pacific region


low-value/ trash fish

Share of total catch

Dominant gear1

Year of estimation




71 000


Gill nets (48)
Non-mechanized set
bags (42)



5 316 000





271 000





78 000


Trawl (41) 
Danish seine (22) 
Purse seine (12)



765 000


Trawl (95)


Viet Nam

933 183




1 Figures in parentheses are percentages.

Source: APFIC country studies cited in FAO. 2005. Asian fisheries today: the production and use of low-value/trash fish from marine fisheries in the Asia–Pacific region, by S. Funge-Smith, E. Lindebo and D. Staples. RAP Publication 2005/16. Bangkok.


Low-value/trash fish (using the broader definition) are an important food source for poor people in many developing countries. Small-scale fishers generally keep low-value/ trash fish for home consumption, after selling other fish with higher market demand. Some of the low-value/trash fish are consumed fresh while some are preserved or processed (e.g. into fish sauce or pastes). the proportion of low-value/trash fish used for human consumption can be quite high; for example, in Bangladesh about 60 000 tonnes of the total 71 000 tonnes of low-value/trash fish landed are consumed either directly or in a dried form.

Varying amounts of the low-value/trash fish are used for livestock/fish feed in the different countries (100 percent in China and Thailand – by definition, and little in Bangladesh and India). A conservative estimate for the amount of fish used for livestock/fish food in Asia would be in the order of 25 percent of the capture fisheries production.

Box 13

Low-value/trash fish prices

At the local level, prices of low-value/trash fish vary according to the species, season and abundance of other fish and fishery products. At the low end, fresh low-value/trash fish have been known to fetch as little as US$0.04 per kg (e.g. in Thailand), while their price can be as high as US$1.50 per kg (e.g. in India). Fishmeal-producing industries in the Asia–Pacific region, however, buy low-value/trash fish at prices ranging from US$0.25 to US$0.35 per kg, depending on the protein concentrations of the fish.

There also has been considerable innovation and diversification into new fish products in recent years in an attempt to utilize previously unwanted bycatch, especially from shrimp and finfish trawlers.

Using FAO statistics for capture and aquaculture production in the region, a very approximate “back of the envelope” calculation can be developed to trace the flow of fish products through direct and indirect human use (Figure 40). For 2003, the recorded marine capture fishery landings in the Asia-Pacific region amounted to 39.3 million tonnes (for all carnivorous and omnivorous fish, excluding molluscs and seaweeds), with about 1.8 percent discarded,9 giving a total capture figure of approximtely 40.0 million tonnes. Of this, 29.5 million tonnes were used directly for human consumption and 9.8 million tonnes (25 percent) used for livestock/fish. the total aquaculture production in the region for all fish (again excluding molluscs and seaweeds) is estimated at 28.0 million tonnes. this indicates that approximately 50 percent of fish for human consumption produced in the Asia-Pacific region comes directly from capture fisheries, while 50 percent comes through an aquaculture pathway (this fish is consumed both within the region and exported).


Several issues concerning low-value/trash fish need to be resolved in order to ensure that fisheries of the Asia-Pacific region contribute more to the region’s sustainable development.

Increasing demand for low-value/trash fish for aquaculture and other animal feeds

FAO estimates that an annual global production increase of 3.3 percent until 2030 is feasible in the aquaculture sector.10 the International Food Policy research Institute (IFPRI) gives an estimate of some 2.8 percent until 2020.11 the production of higher-value species will increase the most, given the rising demand for these fish products. the largest rise in production is expected to be in China.

In many areas, these culture practices have been transformed from extensive systems to semi-intensive and intensive culture systems, for which increasing amounts of feed are required. \Fishmeal remains the preferred protein source for most aquaculture feeds. the fishmeal component of feeds can be replaced by vegetable protein (e.g. soya) or monocellular proteins, but the economics of this practice currently remain unattractive. It is worth noting that chicken, cattle and pigs do not naturally feed on fish and therefore the inclusion of fishmeal in feeds for these animals is a nutritional or economic convenience rather than an absolute necessity; the same cannot be said for carnivorous fish.


Competition between use for fishmeal versus use for human food

There is a growing conflict between those who favour using low-value/trash fish for animals and fish versus those who argue it should be used for human consumption. Some argue that it would be more efficient and ethical to divert more of the limited supply to human food (e.g. in the form of value-added products). However, without external interventions (such as incentives and subsidies), it will be the economics of the different uses of low-value/trash fish in different localities that will channel the fish one way or the other. For example, in Viet Nam, as the national demand for fish sauce is expected to double over the next ten years, the competition for mixed low-value/trash fish will increase between those who culture catfish (Pangasius) and those who use these fish as raw material for low-cost fish sauce. In contrast, culture operations for high-value marine finfish and lobsters can afford to pay more for anchovy than can fish sauce manufacturers in central Viet Nam. the purchasing power of those who culture higher-value species will tend to draw on lower-priced capture fishery resources. Where this happens, it is important to appreciate the employment and income generation afforded by high-value aquaculture and factor in the ability of those who are employed in this activity to purchase food, rather than produce it or catch it directly.

Sustainability of harvesting

Low-value/trash fish have ready local markets and can be sold easily in many landing sites, but may have relatively limited markets beyond these areas in view of their poor quality, appearance, size or bony nature. Hence, there seems to be little incentive to discourage the harvesting of low-value/trash fish given their important contribution to aquaculture, overall employment and consequent export earnings. Also, the low-value/ trash fih catch is based on a large number of short-lived, highly productive species for which, apart from targeted low-value/trash fisheries in China, there is little evidence of current overexploitation leading to reduction in overall fish production.

The concern, for both capture fisheries and aquaculture, is that there is no way of knowing how sustainable this system might be. the WorldFish Center has analysed low-value/trash fish trends in several countries based on past scientific trawl surveys. the results show that many families of fish that include both low-value/trash fish species and commercial species have suffered severe declines in abundance, whereas families containing only low-value/trash fish species have been less affected.12

A further aspect of the sustainability issue is that the low value of these fish does not reflect their high ecological value. removing large quantities of them from the environment creates a void in the food chain, which could also lead eventually to the reduction or loss of larger fish species. Moreover, fishing with demersal gears that destroy habitats adds to the overall ecological impact.

Growth overfishing – harvesting juveniles of commercial species

An issue related to that of low-value/trash fisheries is the capture of juvenile fish of important commercial species (so-called “growth overfishing”). Between 18 and 32 percent of low-value/trash fish in the Gulf of Thailand are juveniles of commercially important fish species. Given a chance to grow to a larger size, these high-value species could, when harvested, yield much more in terms of total quantity landed and, more importantly, in terms of value.

Juvenile/trash fish excluder devices have been tested in trawl nets in several Southeast Asian countries. However, given the many conflicting uses for low-value/trash fish, it is difficult to envisage a management system that optimizes the supply of these fish for both human and livestock/fish uses and at the same time excludes juvenile fish.

Lack of incentives for improved post-harvest

Because of the high demand for low-value/trash fish and the good economic gains they offer, many fishers have decided that careful handling and chilling are not essential. According to some reports in Viet Nam, 20–30 percent, or even 50–60 percent of high-value fish on some offshore trawlers, become low-value/trash fish as a result of poor storage.

Discarding of unwanted fish

Discarding practices are seen by many as a waste of fish and fish protein. For the Asia–Pacific region, discards in most fisheries in China and Southeast Asia are now considered to be negligible owing to the greater utilization of low-value/trash fish as food and feeds. there has also been a change in perception of what constitutes a target species. Given the expansion of markets for low-value fish, almost all catches can now be regarded as “targeted” (i.e. they produce neither bycatch nor discards). Exceptions will, of course, occur: for instance, in Brunei Darussalam, fishing for low-value/trash fish is not permitted (for aquaculture or local consumption), and hence a discard estimate of some 70 percent is still being quoted. Fisheries with high discard rates still exist; these include the Bangladesh industrial finfish and shrimp trawling fishery, which has an estimated discard rate of some 80 percent.


A draft action plan to address the above issues was developed during the APFIC regional Workshop on Low Value and “trash Fish” in the Asia–Pacific region.13 this plan recommends the action outlined below.

  1. Reduce trawling and push net effort (and clearly monitor the effect of capacity reduction).
  2. Introduce improved selectivity of fishing gears/fishing practices.
  3. Facilitate a reduction in the “race for fish” through rights-based fisheries and co-management.
  4. Protect juvenile nursery areas (refugia/closed areas, seasonal closures).
  5. Provide alternative social support measures (including employment).
  1. Improve post-harvest fish handling.
  2. Develop new fish products through processing.
  1. Change from direct feeding to pellet feeding.
  2. reduce fishmeal content by substitution of suitable ingredients in pellets.
  3. Invest in feed research for inland/marine species.
  4. Promote adoption of, and changeover to, pellet feeds.

The challenge is now on how to implement these actions. Several activities have been planned by the APFIC, including a regional Consultative Forum Meeting and the development of recommendations through the Commission.

Conservation and management of shared fish stocks: legal and economic aspects


A shared fish stock is one that is harvested by two or more states (or entities). the stock may be shared by virtue of the fact that it crosses the boundary of a coastal state’s EEZ into one or more neighbouring EEZs (transboundary stock),14 or because it crosses the EEZ boundary into the adjacent high seas, where it may be subject to exploitation by distant-water fishing states (highly migratory or straddling stock),15 or finally because it is to be found exclusively in the high seas (discrete high seas stocks). FAO estimates that as much as one-third of global marine capture fishery harvests may be based on such shared stocks, and argues that the effective management of these stocks stands as one of the great challenges faced in achieving long-term sustainable fisheries. 16

In response to this challenge, FAO, in cooperation with the Government of Norway, convened the Norway–FAO Expert Consultation on the Management of Shared Fish Stocks in October 2002.17 FAO also provided technical support to the Sharing the Fish Conference 06, held in Australia,18 one of the major themes of which was the management of (internationally) shared fish stocks.

Shared fish stocks are more difficult to manage than those confined to the waters of a single coastal state’s EEZ because, with a few exceptions, a strategic interaction develops between and among the states sharing the resource or resources. If, for example, two coastal states are sharing a transboundary stock, the harvesting activities of the first state are bound to have an impact upon the harvesting opportunities of the second state and vice versa. thus, a strategic interaction inevitably develops between the two coastal states, with each state attempting to predict and respond to the harvesting plans of the other.


At the close of the third United Nations Conference on the Law of the Sea in 1982, transboundary stocks were seen as the shared fish stock management problem. It was believed that only a small percentage of world capture fishery harvests would come from fish stocks lying outside the emerging EEZs. Consequently, stocks crossing the EEZ into the adjacent high seas were seen as a minor resource-management problem.19 No one questioned the importance of transboundary fish stocks, which were, and continue to be, ubiquitous. In a thorough study o such stocks, the number of transboundary stocks was estimated conservatively to be in the order of 1 000–1 500 worldwide.20

The legal framework for the management of these stocks is provided by the 1982 United Nations Convention on the Law of the Sea, Article 63(1). the article imposes an obligation upon coastal states sharing a transboundary stock, or stocks, to negotiate in good faith over arrangements for management of the stocks. What the article does not do, however, is to impose an obligation on the states to reach an agreement. If the states are unable to do so, then each state is to manage that segment of the stock within its EEZ, in accordance with its rights and obligations laid down by other parts of the 1982 Convention.21 thus, the Convention does allow for non-cooperative management of the resource or resources. this could be referred to as the default option.

In light of this default option, two questions must be addressed:

  1. What are the consequences, if any, of coastal states adopting the default option and not cooperating in the management of transboundary stocks, at least not beyond the exchange of scientific information? and
  2. What conditions must prevail if a fully fledged cooperative resource management arrangement between and among the coastal states is to be stable over the long run?

If the answer to question (a) is that the negative consequences of non-cooperative management are trifling, then question (b), of course, becomes irrelevant.

In addressing these questions, it should be recognized that the strategic interaction between and among coastal states sharing transboundary stocks referred to earlier plays a critical role in the resource management problem. Economists, in attempting to find answers to questions (a) and (b), find themselves compelled to do so through the lens of the theory of strategic interaction (or interactive decision theory) – popularly known as game theory. Once deemed to be an esoteric specialty, game theory is now so widely used in the field of economics that the Nobel Prize in Economic Sciences has been awarded twice to specialists in game theory, the latter time being in 2005.22 the theory is, moreover, applied widely in other fields, such as international relations, legal studies, political science and evolutionary biology.

The theory of strategic interaction – game theory – is divided into two broad categories: the theory of non-cooperative games and the theory of cooperative games. the insights provided by the theory of non-cooperative games offer guidance in addressing question (a). What these insights warn is that one cannot safely assume that the “players” (coastal states) will find some way to manage their respective shares of the resource effectively. there is a serious risk that the players will be driven to adopt courses of action (“strategies”) that each player knows will be harmful, if not destructive. this goes under the title of the “Prisoner’s Dilemma”, from a famous non-cooperative game designed to illustrate the point.23 these predictions of non-cooperative game theory have been validated many times over in the real world of shared stock fisheries.24 Explicit cooperation in transboundary fish stock management does, other than in exceptional cases, truly matter. Question (b) cannot be avoided.

In turning to the cooperative management of transboundary stocks, two preliminary questions must be dealt with. First, what is the desired level of cooperation? Over 25 years ago, John Gulland distinguished between two levels of cooperation: the primary and secondary levels.25 the primary level of cooperation involves the exchange of scientific information and data alone; the secondary level involves cooperation n the “active management” of the resource(s), which in turn involves determining (i) the allocation of benefits from the fishery, (ii) the optimal resource-management programme through time, and (iii) effective implementation and enforcement. the Norway–FAO Expert Consultation concluded that, while the primary level is useful as a precursor, it is seldom adequate in, of and by itself. Coastal states must be prepared to cooperate in the “active management” of the resource(s).

The second question is: what in fact is to be allocated among the coastal states sharing the resource? Is it shares of the agreed-upon total allowable catch (TAC) between, or among, the coastal state fleets, or is it the net economic returns from the fishery over time? the two are not necessarily the same. Historically, one of the most effective fishery cooperative management regimes, both in terms of the profitability of the fishery and the conservation of the resource, was that focused on the fur seals of the North Pacific from 1911 to 1984. Four states were involved (Canada, Japan, Russia/ Union of Soviet Socialist republics and the United States of America). the fleets of two of the states received annual allocations of zero. Nonetheless, all four states benefited economically from the cooperative management of the resource.26

The theory of strategic interaction, in the form of the theory of cooperative games, highlights the conditions that must be met if the cooperative regime is to remain stable through time. Of course, the allocation of the economic benefits from the shared fishery must be seen to be fair. there is, however, a requirement, or rather a condition, that goes beyond this, which could be referred to as the bedrock condition. the condition is that each participant (coastal state) in a cooperative resource-management arrangement must at all times expect to receive long-term benefits from the cooperative arrangement that are at least equal to the long-term benefits it would receive if it refused to cooperate. In game theory parlance, this is referred to as the “individual rationality condition”.

This bedrock condition, once stated, seems obvious. the report of the Norway–FAO Expert Consultation observes, however, that, although obvious, the condition is often ignored in practice.27

In the first instance, the condition requires that the implementation and enforcement provisions of the cooperative management arrangement be fully effective. If a participating coastal state believes that it has received a “fair” allocation, but also believes that enforcement provisions are so weak that cheating will be encouraged, the state may well calculate that its economic returns from cooperation will fall short of what it could expect to gain from non-cooperation, and will act accordingly.

In the second instance, the individual rationality condition requires that the scope for bargaining should be kept as broad as possible. If, for example, the cooperative resource-management arrangement is such that each coastal state’s economic returns from the fishery are to be determined solely by the harvest of its fleet within its EEZ, the scope for bargaining may be too narrow to ensure a stable cooperative resource-management regime. the report of the Norway–FAO Expert Consultation, in addressing the issue, talks in terms of “negotiation facilitators” (also known as side payments). the report states that the “… development of cooperation can be facilitated by supplementing the allocation of TAC shares by such devices as access arrangements and quota trading (both trading in kind and cash)”.28 If, in fact, what is being shared among the participating states is the flow of net economic benefits from the fishery, then it makes no sense to restrict the allocation of these benefits to TAC shares among the coastal state fleets.

The second fundamental requirement, or condition, that must be met if the cooperative resource-management arrangement is to prove stable over time is that the arrangement be “resilient”. Every cooperative arrangement can be expected to be subject to unpredictable shocks, arising from environmental, economic, political or other factors. If the arrangement lacks flexibility or resiliency, a hitherto stable cooperative arrangement can be easily thrown into disarray, such that the “individual rationality” condition for one or more participants is no longer satisfied.29


The comfortable belief, at the close of the third United Nations Conference on the Law of the Sea in 1982, that fish stocks to be found both within the EEZ and in the adjacent high seas were of minor importance, proved, during the remainder of the 1980s and the early 1990s, to be quite simply wrong. Case after case of overexploitation of such stocks emerged, for example groundfish resources on the Grand Bank of Newfoundland, pollock resources in the Bering Sea “Doughnut Hole”, jack mackerel resources off the coasts of Chile and Peru, orange roughy resources off the South Island of New Zealand and bluefin tuna in the Atlantic and Southern Oceans.30 the problem became so serious that the United Nations Conference on Straddling Fish Stocks and Highly Migratory Fish Stocks was convened from 1993 to 1995 in order to address it. the Conference resulted in the 1995 UN Fish Stocks Agreement,31 which was designed to buttress the 1982 Convention.

Straddling and highly migratory fish stocks are covered in the 1982 Convention, in Articles 63(2) and 64 of Part V on the EEZ and in Part VII on the high seas. the Convention, Part VII in particular, leaves somewhat uncertain the rights, duties and obligations of coastal states and distant-water fishing states (DWFSs) with regard to the high seas segments of straddling and highly migratory fish stocks. this lack of clarity, in turn, made it difficult to establish effective cooperative management arrangements for these stocks.32 the 1995 UN Fish Stocks Agreement was meant to address this weakness.

Under the Agreement, straddling and highly migratory fish stocks are to be managed on a region-by-region basis through RFMOs,33 which are to be open to states (including DWFSs) having a genuine interest in the resources. Only those states belonging to an RFMO, or agreeing to abide by the management and conservation measures established by the RFMO, are to have access to the fishery resources encompassed by the RFMO.34 Each RFMO is, inter alia, called upon to ensure that the management measures for the high seas segments of the resources and those measures for the intra-EEZ segments of the resources are compatible with each other.

The two questions posed above with respect to transboundary stocks – (a) the consequences of attempts to establish cooperative management arrangements being unsuccessful and (b) the conditions that must be met if a cooperative management arrangement is to be stable through time – are equally relevant to the management of straddling and highly migratory stocks. Once again, economists, in attempting to answer these questions, find themselves compelled to do so through the lens of the theory of strategic interaction (game theory).

The answer to the first question is the same as the answer provided in the context of transboundary stocks: non-cooperative management carries with it the threat of a “Prisoner’s Dilemma” type of outcome with overexploitation of the resources. Indeed, it was the manifest consequences of non-cooperative management of straddling and highly migratory stocks that provided the motivation and rationale for convening the UN Fish Stocks Conference.35 Once again, cooperative management is of critical importace to the sustainability of these stocks.

Moving to the second question, the conditions that must be met to ensure the long-term stability of cooperative resource-management arrangements, discussed in the context of transboundary stocks, apply with equal force to RFMOs. the cooperative management of straddling and highly migratory stocks through RFMOs is, however, a much more demanding undertaking than the cooperative management of transboundary stocks. First, the number of participants in an RFMO is likely to be substantially greater than the typical transboundary stock cooperative management.36 the larger the number of participants, the more difficult it is to achieve stability, if for no other reason than the fact that the enforcement problem becomes steadily greater as the number increases.37

Second, while the participants in a transboundary stock cooperative arrangement can generally be expected to be constant in number and nature over time, this is not the case with RFMOs. A typical RFMO will include DWFSs among its participants, whose fleets are nothing if not mobile. In particular, a DWFS that was not a founding member of the RFMO may request membership subsequently. the 1995 UN Fish Stocks Agreement explicitly calls upon RFMO founding members to accommodate prospective new members or entrants.38 How prospective new members can be accommodated, and persuaded to be members of good standing within the RFMO, without undermining the willingness of founding members to cooperate, is an issue that has not yet been resolved.39 this issue is closely linked to the most marked difference between transboundary stock cooperative arrangements and RFMOs – the threat of “free riding”.

Free riding involves the enjoyment of the fruits of cooperation by non-participants in the cooperative arrangement. If free riding is extensive, participants in the arrangement may calculate that their benefits from cooperation will be less than what they would obtain through non-cooperation – the “individual rationality condition” once again. Free riding is conceivable in a transboundary stock cooperative management arrangement, but real-world cases are very difficult to find.40 In contrast, free riding has been a chronic problem with regard to fishery resources in the high seas.

Fishing activities by non-RFMO participants in the high seas area governed by the RFMO, contrary to the management provisions of the RFMO, are deemed to constitute unregulated fishing, as opposed to illegal fishing. Uncontrolled and unregulated fishing provides strong encouragement for free riding, in spite of Article 8 of the 1995 UN Fish Stocks Agreement.

Free riders can, of course, be encouraged by RFMO members to change their ways and become new members of the RFMO. Is this really a viable solution, however? recent “cutting edge” analysis by economists applying the theory of strategic interaction to straddling and highly migratory stock management suggests that, if unregulated fishing is not curbed, there will be cases in which the circle cannot be squared, in which it is not possible to satisfy all RFMO members, old and new. the attraction of free riding will be too strong. In such cases, the RFMO will prove to be inherently unstable.41 the inevitable conclusion is that, in order for the emerging RFMO regime to prosper, it is of utmost importance that unregulated fishing be effectively curbed. In this context the importance of the IPOA-IUU and its effective implementation cannot be overstated.


Until recently, there was little that could be said about discrete high seas stocks, which had been described as the “orphans of the sea”.42 the legal framework for their conservation and management is provided by Part VII of the 1982 Convention, which obliges sttes to cooperate with each other, negotiate the adoption of measures and, as appropriate, establish subregional or regional organizations. the attention of the international community has focused increasingly on these stocks, particularly as a consequence of a growing concern regarding deep sea fisheries and species. the recent opening to signature of the South Indian Ocean Fisheries Agreement (SIOFA) and the ongoing negotiations towards the establishment of the South Pacific regional Fisheries Management Organisation (SPRFMO) (see p. 56) are illustrative of that trend. An important step forward was also made when the UN Fish Stocks Agreement review Conference addressed high seas discrete stocks within the ambit of the Agreement (see p. 55). thus, the questions raised above also apply to the high seas “discrete” fish stocks.

  1. This section draws on the following sources: FAO. 2005. Habitat rehabilitation for inland fisheries: global review of effectiveness and guidance for rehabilitation of freshwater ecosystems, by P. Roni, ?. Hanson, T. Beechie, G. Pess, M. Pollock and D.M. Bartley. FAO Fisheries Technical Paper. No. 484. Rome; I.G. Cowx and R.L. Welcomme. 1998. Rehabilitation of rivers for fish. Oxford, UK, Fishing News Books; FAO/Deutscher Verband für Wasserwirtschaft und Kulturbau. 2002. Fish passes - design, dimensions and monitoring. Rome, FAO; M. Larinier and G. Marmulla. 2004. Fish passes: Types, principles and geographical distribution -an overview. In R.L. Welcomme and T. Petr, eds. Proceedings of the Second International Symposium on the Management of Large Rivers for Fisheries Volume II, RAP Publication 2004/17, pp. 183-205. Bangkok, FAO Regional Office for Asia and the Pacific; M. Larinier, F. Travade and J.P. Porcher. 2002. Fishways: biological basis, design criteria and monitoring. Bull. Fr. Pêche Piscic, 364(Suppl.); FAO. 2001. Dams, fish and fisheries. Opportunities, challenges and conflict resolution, edited by G. Marmulla. FAO Fisheries Technical Paper No. 419. Rome; and G. Marmulla. 2003. Dams and fisheries. In FAO. 2003. Review of the state of world fishery resources: inland fisheries. FAO Fisheries Circular No. 942, Rev. 1, pp. 29-35. Rome.
  2. FAO. 1995. FAO Code of Conduct for Responsible Fisheries. Rome.
  3. FAO. 1997. Inland fisheries. FAO Technical Guidelines for Responsible Fisheries No. 6. Rome.
  4. The study report was published as FAO. 2005. Responsible fish trade and food security, by J. Kurien. FAO Fisheries Technical Paper No. 456. Rome.
  5. Brazil, Chile, Fiji, Ghana, Namibia, Kenya, Nicaragua, the Philippines, Senegal, Sri Lanka and Thailand.
  6. The article draws on a range of FAO documents and data sources to provide an insight into the current issues surrounding low-value/trash fish production in the region. These include: FAO. 2005. Asian fisheries today: the production and use of low-value/trash fish from marine fisheries in the Asia-Pacific region, by S. Funge-Smith, E. Lindebo and D. Staples. RAP Publication 2005/16. Bangkok; and FAO. 2005. Discards in the world's marine fisheries: an update, by K. Kelleher. FAO Fisheries Technical Paper No. 470. Rome.
    A number of comprehensive country studies were also initiated by the APFIC and have provided the basis for much of the information discussed. A recent review carried out under the auspices of the Australian Centre for International Agricultural Research (ACIAR) was also used: P. Edwards, L.A. Tuan and G.L. Allan. 2004. A survey of marine low trash fish and fishmeal as aquaculture feed ingredients in Vietnam. ACIAR Working Paper No. 57. Canberra.
  7. "Fishing down the food chain" refers to the practice in some tropical demersal coastal fisheries whereby larger and more valuable fish species (often of a higher trophic level, e.g. carnivores such as bream, sharks and rays) become overfished, and fishing practices change to catching large quantities of mainly low-value species (often of a lower trophic level, e.g. squid and jellyfish).
  8. An average weighted by the amount of low-value/trash fish caught in the different countries.
  9. FAO. 2005. Discards in the world's marine fisheries: an update, by K. Kelleher. FAO Fisheries Technical Paper No. 470. Rome.
  10. FAO. 2002. The State of World Fisheries and Aquaculture 2002. Rome.
  11. IFPRI. 2003. Fish to 2020 - supply and demand in changing global markets. Washington, DC.
  12. WorldFish Center. 2006 (forthcoming). Regional synthesis on the analysis of "TrawlBase" data for low value/trash fish species and their utilization. Penang, Malaysia.
  13. FAO. 2005. APFIC Regional Workshop on Low Value and "Trash Fish" in the Asia-Pacific Region. Hanoi, Viet Nam, 7-9 June 2005. Asia-Pacific Fishery Commission (APFIC). RAP Publication 2005/21. Bangkok.
  14. With regard to terminology, there is a second school of thought that uses the term "transboundary" as a generic one to denote all fish stocks exploited by two or more states (entities). This school of thought uses the term "shared" to denote stocks to be found within two or more neighbouring EEZs.
  15. Highly migratory stocks are those set forth in Annex I of the 1982 Convention on the Law of the Sea, and consist primarily of the tuna species. Straddling stocks are all other stocks (excluding anadromous and catadromous stocks) to be found, both within the EEZ and the adjacent high seas. Transboundary stocks and highly migratory/straddling stocks are not mutually exclusive.
  16. Shared fish stocks are also found in inland water bodies, including lakes and riv pose the same cooperative management challenges.
  17. FAO. 2002. Report of the Norway-FAO Expert Consultation on the Management of Shared Fish Stocks. Bergen, Norway, 7-10 October 2002. FAO Fisheries Report No. 695. Rome; FAO. 2004. The conservation and management of shared fish stocks: legal and economic aspects, by G. Munro, A. Van Houtte and R. Willmann. FAO Fisheries Technical Paper No. 465. Rome.
  18. Sharing the Fish Conference 06, Fremantle, Australia, 26 February-2 March 2006 (available at
  19. FAO, 2004, op. cit., see note 17.
  20. J.F. Caddy. 1997. Establishing a consultative mechanism or arrangement for managing shared stocks within the jurisdiction of contiguous states. In D. Hancock, ed. Taking stock: defining and managing shared resources, pp. 81-123. Australian Society for Fish Biology and Aquatic Resource Management Association of Australasia Joint Workshop Proceedings, Darwin, Northern Territory, 15-16 June 1997. Sydney, Australia, Australian Society for Fish Biology.
  21. FAO, 2004, op. cit., see note 17.
  22. The Nobel Prize in Economic Sciences in 2005 was awarded jointly to Thomas Schelling (United States of America) and Robert Aumann (Israel). The press release, announcing the award, read as follows: "Why do some groups of individuals, organizations and countries succeed in promoting cooperation while others suffer from conflict? The work of Robert Aumann and Thomas Schelling has established game theory - or interactive decision theory - as the dominant approach to this age-old question" ( press.html). This is, of course, precisely the question that has to be confronted in the context of shared fish stocks.
  23. The "Prisoner's Dilemma" and its relevance to the management of shared fish stocks is discussed in detail in FAO, 2004, op. cit., see note 17.
  24. Ibid.
  25. FAO. 1980. Some problems in the management of shared stocks, by J.A. Gulland. FAO Fisheries Technical Paper No. 206. Rome.
  26. FAO. 1994. Marine fisheries and the law of the sea: a decade of change. FAO Fisheries Circular No. 853. Rome; S. Barrett. 2003. Environment and statecraft: the strategy of environmental treaty-making. Oxford, UK, Oxford University Press.
  27. FAO, 2002, op. cit., see note 17.
  28. Ibid., p. 8.
  29. An example of a cooperative fisheries management arrangement being upset by an environmental shock is provided by the Canada-US Pacific Salmon Treaty. See: K.A. Miller. 2003. North American Pacific salmon: a case of fragile cooperation. In Papers presented at the Norway-FAO Expert Consultation on the Management of Shared Fish Stocks. Bergen, Norway, 7-10 October 2002, pp. 105-122. FAO Fisheries Report No. 695, Suppl. Rome.
  30. United Nations. 1992. The law of the sea: the regime for high seas fisheries: status and prospects. New York, USA; FAO. 2006. The state of the world's highly migratory, straddling and other high seas fish stocks, and associated species. FAO Fisheries Technical Paper No. 495. Rome. Of the world tuna stocks for which the state of exploitation has been assessed, 29 percent are estimated to be depleted or overexploited. Bluefin tuna stocks figure prominently in this estimate (FAO, 2006, pp. 15-16).
  31. The full title is Agreement for the Implementation of the Provisions of the United Nations Convention on the Law of the Sea of 10 December 1982 relating to the Conservation and Man Stocks.
  32. See G. Munro. 2000. The UN Fish Stocks Agreement of 1995: history and problems of implementation. Marine Resource Economics, 15: 265-280.
  33. FAO, 2004, op. cit., see note 17.
  34. Ibid.
  35. Munro, Van Houtte and Willmann remark that "... the overexploitation of straddling/highly migratory fish stocks worldwide ... bears powerful testimony to the predictive power of the economic analysis of the non-cooperative management of such resources". See FAO, 2004, op. cit., note 17, p. 45.
  36. Transboundary stock cooperative arrangements with large numbers of participants do exist, but these are the exception, not the rule. In the case of RFMOs, large numbers of participants are the rule, not the exception.
  37. With a large number of participants (players), it is standard in game theory analysis to talk of coalitions. All the players together constitute the "Grand Coalition". There can, in addition, be subcoalitions. In such a game, it is not sufficient to worry about individual players deciding they would be better off by not cooperating; stability of the Grand Coalition also requires that each subcoalition can expect to receive returns from cooperation that are at least as great as it would expect to obtain by going off and competing against the rest.
  38. Articles 8, 10 and 11.
  39. FAO, 2004, op. cit., see note 17.
  40. Ibid.
  41. M. Lindroos. 2002. Coalitions in fisheries. Helsinki School of Economics Working Paper W-321; P. Pintassilgo. 2003. A coalition approach to the management of high seas fisheries in the presence of externalities. Natural Resource Modeling, 16: 175-197.
  42. FAO, 2004, op. cit., see note 17. The issue was also discussed in FAO. 2004. The State of World Fisheries and Aquaculture 2004. Rome, pp. 91-99.

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