3. Management measures and approaches

3.1 Introduction

The measures available to managers to adopt an EAF will, at least in the short term, be an extension of those conventionally used in TROM. Thus the range of input and output controls and technical measures (including spatial measures) used to regulate fishing mortality remain highly relevant; but these controls will need to be considered in a broader context. This means recognizing that the range of measures chosen should not only address a series of target species concerns, but should also enhance ecosystem health and integrity. Managers should consider as far as possible a coherent mix of approaches that takes account of the interdependencies and functioning of the ecosystem. Apart from managing the direct effects of fishing activity, fishery managers will need to be aware of other measures that are available for managing populations (e.g. restocking and culling). Similarly, habitats may be modified to enhance the populations of target species or to restore degraded areas.

While population and habitat manipulation may lie partly within the remit of fishery management bodies, there are many other issues, generally within the competence of other agencies, that concern fisheries managers. These may be highly relevant in an EAF context; they include such issues as the impact associated with human activities on land and sea leading to habitat destruction, eutrophication, contaminants, CO2 emissions, litter, accidental introduction of exotic species through ballast water, etc. Fishery managers should be proactive in these circumstances to ensure that the appropriate authorities include all those involved in fisheries as important stakeholders in management planning and decision-making.

3.2 Options to manage fishing

3.2.1 Technical measures

3.2.1.1 Gear modifications that improve selectivity

Most fishing gear affects marine life in one way or another. One major impact is that gear is used to remove the larger fish from a population and thus to change the size composition of the targeted species. In many fisheries, the gear also has an impact on non-target organisms. They are captured as well, and this by-catch is frequently discarded because of its low economic value, prohibitions on landing or space limitations on board the vessel. The consequences for the ecosystem can be severe. For example, discarding by-catch can often change the trophic structure of entire ecosystems with the encouragement of scavengers, as is seen in many shrimp fisheries around the world. Size selective harvesting can, under some circumstances, lead to genetic changes in affected populations, such as changes in growth and in size and age at first maturity. Under EAF, these effects need to be considered more seriously.

Size selectivity of target species

Mesh size restrictions can be a useful measure to avoid capturing individuals of target species in the immature stages, but they have limitations in multi-species fisheries. When organisms of different shapes and sizes occur on the same fishing ground, immature individuals of a co-occurring larger species might still be captured.

When considering introduction of mesh size regulation in a trawl fishery, it is also important to consider the survival rate of the organisms that escape through codend meshes. If mortality is high, the anticipated benefit of larger meshes may not be achieved. Selectivity can be improved through a variety of methods other than mesh size, including the use of square mesh, sorting grids and other devices which enable the unwanted portion of the catch to escape.

Non-target species selectivity

Tools that reduce capture of non-target species in fisheries are known as by-catch reduction devices. Some successful examples include:

• turtle excluder devices (TEDs);
• sorting grids that assist in allowing unwanted by-catch to escape;
• circle hooks and blue dye baits that reduce incidental capture of turtles in longline fishing;
• scaring lines positioned above a longline gear during setting, thawed bait, night setting with minimum ship light, weighting the line, underwater setting, prohibition of dumping offal during setting to reduce catching seabirds;
• acoustic pingers to distract marine mammals from becoming entangled in gillnets; and
• modified operational methods and gear modifications that avoid capture of dolphin while purse seining for tuna.

All of these measures have proved to be very effective in different fisheries around the world and there are several examples where there have been economic benefits as well as large ecological benefits, e.g. in the Caribbean trap fisheries, in the Alaskan ground fish fishery and in tropical shrimp fisheries in Australia.

3.2.1.2 Other gear issues

When fishing gear like gillnets and traps/pots are lost during fishing operations, they may continue to capture fish for several weeks, months or even years, depending on the depth and prevailing environmental conditions (light level, temperature, current speed, etc). This “ghost fishing” can be partially limited by using biodegradable materials or some means to disable the gear, through increased effort to avoid losing them, or by facilitating the quick recovery of lost nets. In some areas, active campaigns are undertaken to “sweep” periodically for lost nets in known gillnet fishing grounds.

3.2.1.3 Spatial and temporal controls on fishing

Fishing mortality can be modified by restricting fishing activity to certain times or seasons, or by restricting fishing in particular areas. Such measures can be used to reduce the mortality rate of individuals of either target or non-target species in vulnerable life stages. Where stocks are shared by more than one country, the closures – like other management measures – must be coordinated.

The selective reduction of fishing mortality rate on both target and non-target species generally reduces both the direct and indirect effects of fishing on the ecosystem. Closures may be used to protect critical habitats where fishing activity would otherwise cause damage to the physical structures supporting the ecosystem. They may also help to reduce mechanical disturbance to the benthos and facilitate the establishment of more stable and structured communities.

One form of closure is that of marine protected areas (MPA)s. MPAs range from “no take” to planned “multiple-use” areas. MPAs are often designated for non-fishery objectives, but they can produce considerable benefits for fisheries. MPAs can protect sedentary species, allow a proportion of the stock to remain free of the genetic selective effects of fishing, and may act as refuges for the accumulation of spawning biomass from which replenishment of surrounding fished areas can occur, either through out-migration of fish or dispersal of juveniles. This latter benefit has yet to be demonstrated unequivocally for a range of locations, and may be site-specific.

Commonly, spatial and temporal closures have been established in the context of specific target stocks or fisheries, and it is not unusual for a very large variety of such ad hoc measures to occur in a single ecosystem. While such an approach may have its benefits, there may be advantages in a more systematic scheme where consideration is given to a coordinated attempt to protect a range of habitats and species on a scale which is relevant to the ecosystem concerned. This requires a synthesis of the current understanding of the important elements of ecosystems and an evaluation of the potential benefits (see Chapters 2 and 4.1.3).

It is important to include an evaluation of the overall effect of a closure based on the biology of the species concerned and the nature of the fishery. The success of spatial and temporal closures can be limited if their effect is merely to displace fishing activity and increase mortality of other species or life stages elsewhere. Species that are mobile and move between the protected and non-protected areas may, in fact, gain little protection.

Area closures that permit some fishing may require a large enforcement effort and can therefore be costly. Allowing certain categories of fishing activity can also create loopholes which undermine the intentions of the closure. Management authorities need to consider the likely degree of compliance and enforcement costs in establishing closures, although the advent of vessel monitoring systems (VMS) makes area-based management more enforceable in some regions of the world.

3.2.1.4 Control of the impact from fishing gear on habitats

Fishing gear that touches or scrapes the bottom during fishing operations is likely to produce negative impact on the biotic and abiotic habitats. Because only limited knowledge exists about the long-term effect of such impact, a precautionary approach is recommended in the use of high-impact fishing methods in critical habitats. Use of towed gear with reduced bottom contact is a technical option in such areas. Prohibition of certain gear in some habitats is another, e.g. trawling in coral reef and seagrass areas. A third option is to replace a high-impact fishing method with one with less impact on the bottom, e.g. trapping, longlining or gillnetting.

3.2.1.5 Energy efficiency and pollution

Many modern fishing vessels use fossil fuel for propulsion, for operating the fishing gear and for the preservation and processing of the catch. The impact of exhaust gas emission of dangerous substances, including CO2, has been fully recognized, and technological innovations that reduce such emissions are encouraged. Energy optimization can be achieved through improved efficiency of fishing gear as well as through improved management that lead to less fishing effort being required.

3.2.2 Input (effort) and output (catch) control

3.2.2.1 Controlling overall fishing mortality

The direct effects of fisheries on marine ecosystems are to increase fishing mortality rate among target and non-target species and to affect habitat. The fishery management methods that are used to control fishing mortality are often referred to as input and output controls. Input controls apply to capacity (which is closely related to the fishing mortality a fishing fleet could generate if the entire fleet were to fish full time) and effort (which is the actual amount of fishing activity). Output controls apply to the catch that results from the fishing effort. Well-known fisheries models are used to relate both catch and fishing effort to fishing mortality.

Capacity limitation seeks to restrict the total size of the fleet, thus reducing both fishing mortality and the pressures on decision-makers to allow higher fishing mortality. Capacity controls have the potential to reduce fishing mortality on entire species complexes in exactly the same manner as effort or spatial/temporal access limitations.

Effort limitation seeks to restrict the fishing activity of fleets and hence reduce fishing mortality. Because this operates at the fleet level, there will be a reduction in mortality among all species involved in the fishery, and this may be advantageous when dealing with multi-species fisheries. Although there is a considerable difference in the likely social and economic effects of different effort limitation regimes, the net effect of reducing the amount of fishing will produce benefits for the ecosystem, provided the continual improvement in efficiency (“effort creep”) does not cancel out the effect over time.

In current fisheries practices, the main limitations of any of these controls are that they do not directly constrain the fleet from targeting and depleting an individual stock. From an EAF viewpoint, these input controls have the virtue of restricting the overall pressure on the ecosystem, thus offering the potential of limiting negative impacts. However, there is also considerable danger that fishing mortality will steadily increase if increasing efficiency is not monitored and controlled. While increases in efficiency, if unchecked, will increase the fishing mortality in the target and by-catch species, some technological progress such as development of echo-sounders and satellite navigation may also enable fishermen to direct more of their effort towards the target species and thus diminish the impact on non-target species.

3.2.2.2 Catch controls

Catch controls in the form of catch limitations are aimed at directly reducing fishing mortality on target species. If complemented with by-catch controls (such as quotas) they have the potential to protect associated species. They have proven successful in some cases, including in multi-species fisheries, but have sometimes also led to undesirable outcomes (high-grading, increased discarding, etc.). In terms of an EAF, however, in a mixed-species fishery, consideration needs to be given to the different vulnerabilities and productivity of the various species. It will be necessary to implement a set of consistent catch limits across the range of target and by-catch species to reflect these differences and addresse desired ecosystem related objectives (such as maintaining food webs). Catch limits for target species may need to be modified to control catches of more vulnerable species.

3.2.3 Ecosystem manipulation

In some situations, technology and understanding of marine ecosystems have advanced to the point where ecosystems may be manipulated to achieve societal objectives that include conservation and restoration. Such manipulation (in the form of, for example, stock enhancement, culling or habitat restoration) may be an attractive option to mitigate negative impact from the past (like overfishing or habitat destruction). However, mitigation is rarely completely effective, carries with it some risk of unexpected consequences; it may also be costly. There is still little experience with successful ecosystem manipulation, and knowledge is insufficient to allow for sound prognoses. Avoiding the causes of the problem in the first place is a much more desirable approach.

3.2.3.1 Habitat modifications

Preventing habitat degradation. Habitat preservation in marine fisheries is the key to EAF, because it underpins the health of exploited ecosystems. Managers need measures to prevent damage to habitats, to restore damage where it has occurred and to increase habitat where required. Such measures must be in harmony with other ecosystem functions. Various types of fishing pose threats to the integrity of the habitats that support fisheries resources and other components of the ecosystem. Apart from notorious practices such as using dynamite and fishing with poison, already widely outlawed, several other practices may result in physical and biological damage to the seafloor. The different measures needed to reduce such impacts include:

• prohibition of destructive fishing methods in ecologically sensitive habitats (such as seagrass beds);
• prohibition of intentional cleaning of the seafloor to facilitate fishing; and
• reduction of the intensity of fishing in some fishing grounds to ensure that non-target, habitat-forming species are not reduced below acceptable levels.

Providing additional habitat. In situations were it is evident that insufficient habitat is available to support species of interest or concern, additional habitat can be created in two ways. The first measure applies where habitat has been damaged or lost and involves re-establishing mangroves, seagrasses and coral reefs. Such rehabilitation programmes should not be implemented unless the problems causing the damage in the first place have been adequately addressed. The primary objective is to re-create the physical structure needed to provide shelter for animals and a substrate for forage organisms. Ideally, rehabilitation programmes should aim to increase biodiversity, so they should aim to be multi-species rather than monospecific enhancements. In some cases, simply providing the conditions necessary for survival of propagules (coral larvae, seagrass seeds) arriving from nearby areas of habitat will result in restoration of habitats. Because many species of fish use different habitats as a continuum during their development, restoring only some habitats may not achieve the full potential of a rehabilitation programme to improve productivity or biodiversity.

The second method is to construct artificial habitat. Well-designed and -located artificial habitats have the potential to improve production by increasing the settlement success of juveniles in years of abundant seed supply (e.g. larvae). Artificial habitats may also play an integral part in a restocking or stock enhancement programme by permitting a larger number of animals to be released (see below). However, care needs to taken to ensure that the new habitat does not redistribute fish in a way that makes them more vulnerable to overfishing. Artificial habitats may also become a navigation hazard, pollute the ecosystem or disrupt its structure and function. Problems can also occur when the artificial habitats are not robust enough to prevent them from breaking up during storms and littering the seashore.

Decisions to increase the amount of structural habitat will involve choices about the relative value of different components of the ecosystem (habitats and species), because creation of one habitat will be at the expense of another. Artificial habitats are also expensive to construct and it may be more effective to protect the existing natural and renewable forms of fish shelters, such as seagrass beds.

3.2.3.2 Population manipulation

Restocking and stock enhancement

Target species that have been heavily over-exploited in some fisheries ecosystems can potentially be restored by releasing cultured juveniles to rebuild the spawning biomass, and then protecting the released animals, the remnant wild stock and the progeny until the population increases to the desired level. This process is known as restocking, and differs from stock enhancement (see below). The former aims to rebuild the stock back up to viable levels, while the latter supplies additional stock to harvest. However, as there are often high costs involved in restocking programmes, careful analysis is needed to determine whether the goals of rebuilding stocks can be achieved by other management measures. In general, restocking should be considered only when other forms of management are incapable of restoring populations to acceptable levels, and it should be coupled with controlled fishing capacity and reduced overfishing. If restocking is needed, and the species is part of a mixed fishery that need not otherwise be closed, restocking can be carried out in MPAs.

To reduce the risks of adverse effects on remnant wild individuals of the same species or other species in the ecosystem, restocking programmes must incorporate: (i) hatchery procedures that prevent loss of genetic diversity by guarding against inbreeding and selective breeding and (ii) quarantine protocols that prevent the transfer of pathogens from cultured animals to the wild.

Where managers wish to increase the yields of particular species from ecosystems, release of cultured juveniles in “stock enhancement” can sometimes be used to manipulate population levels. This process aims to overcome recruitment limitation, which occurs when the natural supply of juveniles falls short of the ability of the habitat to support the desired stock level. As with restocking programmes, careless hatchery practices could also result in the release of individuals unfit for survival in the wild, modification of genetic diversity and the introduction of diseases.

Factors to be considered in determining the benefits and costs of stock enhancement programmes include: (i) the need to minimize production of hatchery-reared juveniles by optimizing the scope for natural replenishment by wild stocks, (ii) the abundance of predators and prey at proposed release sites, and (iii) the need for independent assessments to determine whether the enhancement programme is achieving its goals and whether it is having adverse effects on the ecosystem. It may also be necessary to provide additional habitat to support the increased numbers of enhanced species.

Culling. This measure usually aims to reduce the abundance of predators or species that compete for the same trophic resources, in order to increase the yields of target species or to maintain the balance of the trophic structure. However, such food-web manipulation needs to be carried out with caution to ensure that it produces only the desired effect and does not result in unwanted changes in abundance of other important components of the ecosystem or threaten the survival of the species culled. An adaptive approach is needed, which may benefit from planned experimentation in some cases. Consideration should first be given to the rebuilding of target species populations through other, more conventional, fisheries management measures. Large-scale culling should be conducted only after the full implications of the manipulation have been thoroughly investigated.

Intentional introductions. Although new fisheries can be created by introducing species, there is a high risk of causing detrimental changes in coastal ecosystems. A precautionary approach is needed here, but this does not mean that the measure should never be considered. Some introductions of marine species have resulted in social and economic benefits with no apparent impacts on other components of the ecosystem. Fisheries for trochus in the Pacific and scallops in China are good examples.

A comprehensive risk assessment should be undertaken before considering the creation of new fisheries based on introduced species so as to understand the benefits and consequences of such measures. Steps to be undertaken in a risk assessment should include a detailed understanding of issues such as the trophic level of the species, reproductive potential and requirements, interactions with other species, introduction of pathogens and parasites, and effects on demand for and supply of other species.

3.2.4 Rights-based management approaches

The dangers and consequences of allowing open access to fisheries are now well understood (see Section 3.2, FM Guidelines), where the different options for limiting access and their properties are also described. The Code of Conduct stipulates:

“States should develop, as appropriate, institutional and legal frameworks in order to... govern access to them (coastal resources) taking into account the rights of coastal fishing communities” (para.10.1.3).

A well-defined and appropriate system of access rights in a fishery produces many essential benefits, most importantly ensuring that fishing effort is commensurate with the productivity of the resource and providing the fishers and fishing communities with longer-term security that enables and encourages them to view the fishery resources as an asset to be conserved and treated responsibly.

There are several different types of use rights. Territorial use rights (TURFs) assign rights to fish to individuals or groups in certain localities. Limited-entry systems allow only a certain number of individuals or vessels to take part in a fishery, with entry being granted by way of a license or other form of permit. Alternatively, entry may be regulated through a system of effort rights (input rights) or by setting catch controls (output rights), where the total allowable catch (TAC) is split into quotas and the quotas allocated to authorized users.

Each type of use right has its own properties, advantages and disadvantages, and the ecological, social, economic and political environment varies from place to place and fishery to fishery. Therefore, no single system of use rights will work under all circumstances. It is necessary to devise the system that best suits the general objectives and context for each case, and this system may well include two or more types of use rights within a single fishery or geographic area. For example, a fishery that includes artisanal and commercial fishers could make use of TURFs, effort quotas and catch quotas to regulate access in the different sectors in a way that suits the nature of each, and gives due attention to the productivity of the resources. By way of example, A fishery manager’s guidebook by FAO tentatively suggests:

• TURFs may be particularly suitable for the management of sedentary resources;
• effort rights may be more effective and practical than catch rights where there are no reliable estimates of biomass or where good monitoring of catches may be impractical (or where species diversity is high);
• catch rights may best facilitate the management of highly migratory and transboundary stocks where the allowable catch must be divided amongst the participating nations; and
• effort management may be more effective where a fishery uses primarily the same gear type, whereas in a fishery using many different gear types, catch rights may be preferable.^[6]

EAF requires that all the uses and users of a fishery resource be considered and reconciled, and that interactions between different fisheries within the designated geographic area be taken into account. This will mean that the systems of access rights across different fisheries or different fishery sectors within the management area should be mutually compatible and, overall, that the total effort applied should be commensurate with the productivity of the ecosystem and its component parts. While this may be a demanding and difficult task to implement, often with significant political implications, it is essential for sustainable use of ecosystems and, once in place, will greatly facilitate management of the fisheries and their operation.

3.3 Creating incentives for EAF

EAF may be easier to implement if the rules and regulations applied under a so-called control and command (C&C) form of management are supplemented, or even replaced to the extent possible, with more appropriate incentive measures to achieve EAF. The idea of incentives is to provide signals reflecting public objectives while leaving some room for individual and collective decision-making to respond to them (further elaboration is given in Annex 5).

Different kinds of incentives can be developed in isolation or in combination.

• Improve the institutional framework (definition of rights and participatory processes).
• Develop collective values (education, information, training).
• Create non-market economic incentives (taxes and subsidies).
• Establish market incentives (eco-labelling, and tradable property/access rights, as discussed above).

Incentives play indirectly through the determinants of individual/collective choices, such as the profit motive or normative values. Market or social forces can be very efficient vectors to force the global outcome of individual actions towards collectively set objectives.

Any of these instruments relies to some degree on command and control. Creating the conditions for an efficient market for property rights requires that these rights be legally set and effectively enforced. Similarly, creating a market-based incentive for environmentally-friendly production methods through product eco-labelling requires that certification standards be established and enforced. Incentives and command and control should be seen as complementary, having relative advantages or disadvantages depending on what they are supposed to achieve. Presently, the full range of available incentive instruments is probably underused, with a continuing bias towards command and control.

3.4 Assessing costs and benefits of EAF

3.4.1 EAF management costs and who pays

The shift to EAF may in most, if not all, cases imply higher management costs that include acquisition of additional information, planning and consultative decision-making processes involving a broader range of stakeholders/interest groups, and additional monitoring, control and surveillance. Although higher management costs may often be out-weighed by the long-term benefits of implementing EAF, the question of who pays becomes important. The idea of the fishing industry paying some of the fishery management costs is becoming increasingly accepted and adopted. However, the fact that EAF responds to wider societal needs requires an explicit policy on how the incremental management costs of EAF should be divided between benefits derived by those dependent on fishing for food, livelihood and employment, and benefits to society at large. Where countries are given the task of managing global ecosystem goods and services, consideration may have to be given to whether incremental management costs should be carried by the international community.^[7]

In considering global ecosystem goods and services such as bio-diversity or conservation of endangered species, the issue arises whether valuation should be based on national or local preferences, or take into account preferences of the citizens of other countries or the international community at large. It also needs to take note of goals expressed in international conventions. On the other hand, valuation based on what the most affluent citizens of the globe are willing to pay could result in policy prescriptions that are unfavourable to poor producers and consumers in developing countries. This has given rise to the call for establishing equivalency standards that explicitly take into account differences in wealth and the ability to provide alternative employment and income opportunities.

3.4.2 EAF cost-benefit analysis

The appropriate tools to estimate the costs and benefits of EAF management measures include bio-economic and ecological-economic modelling of various sophistication and total economic valuation methods (see Annex 3). A useful cross-sectoral tool is integrated environmental and economic accounting. A system of integrated environmental and economic accounts (SEEA) provides a comprehensive framework to monitor and analyse the interactions between different sectors of the economy and their individual and aggregate impacts on the environment (see Box 2).^[8]

3.5 Other considerations

Many of the problems facing fisheries management in an EAF context fall outside the direct control of fisheries managers. Examples of such problems include:

• eutrophication of coastal waters resulting from excess nutrients from agriculture and sewage, which cause toxic algal blooms and affect the health of seagrass and coral reef habitats (by encouraging growth of epiphytes, for example);
• sediment loads from agriculture, forestry and construction of infrastructure in catchment that degrade coastal ecosystems, particularly the critical coral reefs and seagrass habitats;
• destruction of fish habitats through foreshore development;
• introduction of exotic species through ballast water and on the hulls of ships;
• contamination of fish products through chemical pollution from agriculture and industry;
• competing use of waterways from other sectors, including aquaculture; and
• effects of climate change on distribution of stocks and sea level rise on nursery habitats.

Fisheries managers need to ensure that they are recognized as important stakeholders in the process of integrated coastal management so that they can safeguard the function of the habitats that support fisheries ecosystems from adverse effects stemming from activities in other sectors.