Aquaculture management

Marine finfish aquaculture is a relatively recent phenomenon that has experienced the bulk of its growth over the last three decades. Asia is the leading continent, with a long history of small scale marine farming, a labour-intensive activity that was well integrated with the local environment and within the bounds of available resources.

During the last 30 years it has grown into a large-scale food producing industry, which is now focused on earning foreign currency from exports. The rapid expansion of intensive monoculture systems has led to developments in the sector where the focus has been on raising predominantly carnivorous, highly profitable species that demand large amounts of feed, water and fertilizers. This pattern of expansion has been witnessed worldwide. Intensive marine aquaculture, together with the exploitation of other marine resources, the expanding coastal population, urban and agricultural pollution, capture fisheries, tourism, and recreational industries have all increased the pressure on the world’s coastal ecosystems.

Nowadays, there is a general realization that for aquaculture to be sustainable, management must not only be aware of the technological issues but also understand the environmental effects, as well as socio-economics issues and markets. Intensive aquaculture, particularly when dependent on fishmeal for the feeding of carnivorous species, is the form of farming most questioned in terms of sustainability (Folke, Kautsky and Troell 1994, 1997; Naylor et al. 1998, 2000). Aquaculture is considered a source of potential danger to coastal ecosystems, when it is not managed correctly. Aquaculture management must be included as part of an Integrated Coastal Management (ICM) plan. The concept of ICM was developed in the 1990s, and has been widely embraced around the world. The management of capture-based aquaculture must now be viewed within this environmental concept, and the influence of ICM policies on it are increasing.
240 9 - MANAGEMENT OF RESOURCES AND CULTURE PRACTICES
A practical consideration for managing aquaculture within the ICM environment is the consideration of environmental carrying capacity, which for aquaculture can be defined as the level of production that a given area (water body) can accommodate without causing significant impacts to the surrounding environment or other resource users (Donnan 2000). GESAMP (1986) defined this capacity as “a property of the environment and its ability to accommodate a particular activity or rate of an activity … without unacceptable impact”.
More specifically, in terms of biological and chemical parameters, GESAMP (1996) defined environmental capacity as:
? the rate at which nutrients are added without triggering eutrophication;
? the rate of organic flux to the benthos without major disruption to natural benthic processes;
? the rate of dissolved oxygen depletion that can be accommodated without mortality of the indigenous biota.
As ICM programmes are established on a long-term basis, there are a few examples of the application (with aquaculture as a factor) that can be used (Table 79).

Table 79. Some ICM programme applications

Major international initiatives for ICMs are the adoption of Chapter 17 (oceans and coasts) of the Rio de Janeiro 1992 Agenda 21 (www.un.org/esa/sustdev/agenda21.htm), Articles 9 (aquaculture development) and 10 (Integration of Fisheries into Coastal Area Management) of the FAO Code of Conduct for Sustainable Fisheries (FAO 1995), and, more particularly for aquaculture management, the development of a series of Coastal Zone Management (CZM) systems around the world. The main points contained in the 2002 Johannesburg plan (www. johannesburgsummit.org) are related to the promotion of the “ecosystem approach” for the protection of marine biodiversity, and from the beginning of 2004, a monitoring system which evaluates the marine environment. The main goal for fisheries is the adoption of strategies and measures necessary to generate sustainable fisheries by 2012.
Despite their theoretical advantages, the more comprehensive (National, Regional) forms of ICM are unlikely to offer an effective solution to the immediate needs of improved planning and management in the areas of existing, or rapidly developing coastal aquaculture activities.

National and Regional aquaculture management

There is no single planning or management framework tool that can be universally applied to promote more sustainable coastal aquaculture development. The importance of legal, procedural and planning frameworks designed to facilitate sustainable aquaculture development is emphasized in the Code of Conduct for Responsible Fisheries (CCRF) (FAO 1995). This promises to have a significant impact worldwide on the development of regulatory systems for aquaculture in the coming years. Article 9 of the CCRF deals with aquaculture development and sets out a wide range of relevant principles and criteria. The first principle is that States should establish, maintain and develop an appropriate legal and administrative framework which facilitates the development of responsible aquaculture. FAO has also produced technical guidelines for responsible aquaculture development (FAO 1997b), which are intended to provide general advice to support and implement Article 9 of the CCRF.
Progress has also been made in the application of the hazard analysis critical control points (HACCP) system in aquaculture (see also the following chapter) and FAO has published general guidelines for seafood quality (Huss 1993). In addition, FAO is currently involved in reviewing the draft Code of Hygienic Practice for the Products of Aquaculture under the auspices of the Codex Alimentarius Committee on Fish and Fishery Products. This Code deals with key hygienic factors involved in all aspects of finfish and crustacean farming, from location and layout of aquaculture facilities to end-product specifications and the production of an HACCP system. The Code is advisory in nature and is intended to be used as a guideline for preparing national quality standards and fish inspection regulations by countries that do not possess fully developed legal regulations (De Fontaubert, Downes and Agardy 1996).
In many countries laws regulating aquaculture are poorly developed and frequently consist only of a few articles pertaining to capture fisheries legislation. However, during the last few years there has been a growing interest in many countries to develop a comprehensive regulatory framework for aquaculture that will protect the industry, the environment, other resource users and consumers (New 1999). While capture fisheries are generally regulated by a single government department, aquaculture is frequently regulated by many agencies under a variety of laws. This means that developing a comprehensive regulatory framework for aquaculture is often a legally and institutionally complex process. Often it involves drafting or amending legislation that addresses a variety of issues, e.g. land use planning and tenure; water extraction, use and discharge quality; fish movement; disease control and notification; pharmaceutical use; and food quality and public health. It also requires the establishment of institutional arrangements to ensure the co-operation and co-ordination of many different institutions with jurisdiction over natural resources, animal and public health, environment, etc.
Although new comprehensive national laws that regulate aquaculture may be desirable in many countries, other options are now being considered. Developing and passing new legislation is a long process and sometimes takes several years, while the rapid development of the sector has created an urgent need for regulation. These options include the enactment of regulations under existing legislation, and non-legally binding agreements such as guidelines and codes of practice. For example the EU has over 250 different regulations that can apply to fish farming.
Capture-based aquaculture transcends both aquaculture and fisheries legislation. As the sector develops there are likely to be greater areas of conflict and more difficulties for this sector, due to increased legislation in both the fisheries and aquaculture sectors. Capture-based aquaculture needs the development of “soft law” instruments, economic incentives and performance bonds, as well as requirements for international and regional collaboration.

Environmental Assessment (EA) – a technical instrument for aquaculture management

Environmental Assessments (EAs) or Environment Impact Assessments (EIAs) could represent a sound technical approach for the development of sustainable aquaculture management systems, and should be compulsory for all new aquaculture developments. In many cases, where international finance or grants are involved, the sponsor will be required to undertake an EA. The EA is normally part of the feasibility study, and is essential to obtain investment funding. The management of each project needs to develop a monitoring system from the EA, in addition to other mitigation measures, in order to ensure the continuing sustainability of the project in environmental terms.
Capture-based aquaculture presents a series of environmental impacts that need an EA and monitoring system, since this would help to prevent conflicts between coastal users, protect sensitive habitats and improve sustainable development of the mariculture industry. At a national level, where an EA regulation exists, licenses for aquaculture sites are more or less mandatory. These are granted only following the presentation of an Environmental Impact Statement/Study, which is the technical basis for local decision makers (who will take into account other factors including public opinion, private sector/producer associations, environmental organizations, various NGOs, etc.). Table 80 shows some examples of EA national legislation worldwide.
An aquaculture proposal has to satisfy several characteristics that take into account all potential environmental hazards: impacts on the ecosystem (water, sediment, habitats, pelagic components,
Table 80. Environmental Impact Assessment Acts

benthos, other organisms), stock removal, visual impacts (on the visual amenity of the site), odours, noise or vibrations (tourism may decrease due to odours caused by tuna farms, as has happened in Croatia), human health and socio-economic effects.
Mitigation measures have to be included in the EA to prevent or to minimize such impacts. Surveillance monitoring (long-term), site specific monitoring (medium-term) and operation compliance monitoring (short-term) represent important mitigation measures (Figure 145). Management needs to develop contingency plans for the operation, so that if an undesirable impact is detected, alternative operating policies and practices are on hand and the project does not have to cease functioning.

Figure 145. Capture-based Japanese amberjack culture in Japan: monitoring is a tool to assess its sustainability (Photo: M. Nakada)

Aquaculture – specific legislation

In the Mediterranean, there are several legislative instruments governing marine aquaculture activities. For example, Dosdat and de la Pomelie (2000) show that operators in France are regulated by a law that still has to be harmonized with EU directives. Fish farmers have to obtain a permit for the use of maritime public property and an operating authorization, as fish farming is considered by law to be an “activity liable to pollute”. The permit lists the species to be farmed, production levels, culture system, location and some other general specifications of the operation. Farmers have to pay a fee that depends on the size of the activity (e.g. € 8.40 per 100 m2 area, for fish) and not on the actual production value. The authorization consists of an ordinary declaration for a fish production below 20 tonnes per year, and an implemented authorization if this threshold is to be exceeded. This regulation was applied to marine fish farming in 1993. The central document is the Environmental Impact Study (EIS), and the monitoring of aquaculture impacts is undertaken by the Departmental of Veterinary Services (DVS). The most common monitoring scheme for sea-cage farming involves a survey of the benthos (redox potential, benthic fauna, settled organic matter) carried out every six months, a water nutrient analysis (near-shore to the cages) and microbiological monitoring at 3 monthly intervals. Fish farmers have to record every intervention and farming activity (standing stocks, food consumption and ratios, input-output of fish, etc.), accidental mortality and losses, waste management (dead fish, organic matter, fuel) in a report transmitted to the DVS. The use of veterinary products is regulated by EU directive 92/18 (antibiotics, food additives and vaccines) (Dosdat and de la Pomelie 2000).
The above requirements are also needed as part of an HACCP system (see the following chapter) and, although adding to the operating costs of the project, these controls and reporting systems have the potential to add value and assure consumers. The term “environmentally sustainable and responsible aquaculture” is becoming an important “tag” for serious commercial companies.
At both national and local levels there is a lack of standardization. For example the threshold in Ireland is set at 100 tonnes compared to 20 tonnes in France, while in Italy the limit is related to area, not to the production method or density (5 ha for intensive farming). Site choice is also difficult to standardize, due to the local characteristics of coastal zones, which differ greatly from place to place. It is also very difficult to establish a set of effluent standards for open water cage farming systems.
Legislation should aim to regulate fish density, depending on carrying capacity, in order to minimize the environmental effects of fish farming. These effects can be significantly reduced by careful site selection, site carrying capacity assessment, stock density control, and improved feed formulation (artificial feed instead of trash fish). Use of trash fish as fish feed is being regulated in some countries: in Denmark, trash fish has been banned and fish farms have been forced to switch to formulated feeds. Compared with pelleted feed, the use of trash fish leads to a much higher wastage of feed. Research conducted on Hong Kong grouper culture showed that solid wastes could be reduced by 5 433 tonnes (40%) (Chu 1999). Feed wastage is a function of protein intake and the digestibility of the feed (percentage of non-digestible components present), and can be reduced by improved feed technology. For example, ammonia excretion by fish is a function of nitrogen and protein intake (Engin and Carter 2001) and can be kept to a minimum with artificial feed. The levels of nitrogen and phosphorous in feed have decreased, as artificial feed matches more closely the dietary requirements of fish. Modern diets tend to contain more lipids and less binders and carbohydrates. This has resulted in a general reduction improvement in feed conversion ratios (Black 2001).
The application of computer modelling to aquaculture management and monitoring should also be carried out to ensure that the culture activity is environmentally sustainable. A numerical model has been developed that describes the material cycling in Japanese amberjack (Seriola quinqueradiata) culture grounds, and has been successfully applied at Yusu Bay in the Bungo Channel, Japan (Takeoka et al. 1988). The seasonal change in flux of particulate organic carbon in the bottom layer, which consisted of the remainder of the bait and the faecal matter from yellowtail culture, has been calculated using the data and parameters for Yusu Bay. The results fitted well to the flux values of particulate organic carbon into the bottom layer obtained by sediment trap experiments in Yusu Bay.

Grouper management – an example for capture-based aquaculture

The management of capture-based farmed groupers is complicated by several problems, including shortage of capture-based “seed”; disease transfer resulting from international trade in “seed”, high mortality rates in capture and culture, overfishing of grouper adults, etc. Groupers are top predators, sedentary in character and strongly territorial, typically long-lived and slow growing and many assemble in large numbers to spawn. These characteristics contribute to the ease with which over-exploitation may occur, and is engendered by the Live Reef Food Fish Trade (LRFFT). This has already led to calls to include many of the target species in Appendix II or III of the Convention on International Trade in Endangered Species (CITES) (Lau and Parry-Jones 1999). The Nature Conservancy (TNC) has developed a regional strategy in the Asia-Pacific that focuses on developing and applying regional models to sustainable fisheries.
Many different resolutions have been taken to reduce exploitation: the Bahamian government has recently approved the establishment of five no-take marine reserves. All of these sites contain known Nassau grouper spawning aggregations. Although stocks of Nassau grouper in the Bahamas appear to be healthy, these closures (coupled with other research activities) are being implemented to ensure that conservative management measures are taken, as a precaution against stock collapses such as those that have occurred in other locations that once held stocks of this species (Johannes 2000).
Other regulations should be developed to control capture-based grouper “seed”. The availability of capture-based grouper “seed” is often insufficient and unreliable (both in quality and quantity) to meet demand; low production in farming is mainly attributed to lack of seed supply (Chao and Chou 1999; Yashiro et al. 2002; Agbayani 2002). Disease problems due to the high transfer stress can cause high mortality rates in capture and culture. Sadovy (2000) has compiled information on the status of regulations on grouper “seed” capture and exports that concern capture-based aquaculture (Table 81).
A Southeast Asian survey found that while the quantity of “seed” caught was astonishing, the production level was very low. The major causes contributing to this massive mortality are destructive fishing practices and gears, poor post-harvest handling, poor farming practices and conditions, and a generalized lack of experience or knowledge (Sadovy 2000). This review indicated that there is a substantial fishery, and demand, for fish in the 5-10 cm range, but that the removal of this “seed” could have serious consequences for the future of both adult stocks and the contribution of these adults to the future of the “seed” fishery itself. Given the likelihood that there will be a significant increase in natural mortality for the smallest settling fish, several researchers have already proposed that fisheries for very early post-settlement (or even pre settlement) “seed” is a way of gaining benefit from a resource that does not affect its long-term sustainability.
It is necessary to consider further directions and initiatives to attain a better use of biological resources and greater socio-economic benefits from grouper capture-based aquaculture. One possible approach for grouper management is, as Sadovy (2000) suggests, the establishment of nursery areas where the capture fishery and culture operations occur. Another possibility is to protect key “seed” settlement areas and nursery habitats, such as mangrove areas and sea-grass environments in river mouths and estuaries, and to ensure “seed” production by safeguarding spawning adults. Marine protected areas may incorporate key settlement and nursery areas.
Positive steps to address many of these issues are being taken by the Network of Aquaculture Centres in Asia and the Pacific (NACA) and its partners, the Asia-Pacific Economic Cooperation (APEC), the South-East Asian Fisheries Development Center (SEAFDEC), the Australian Centre for

Table 81. Southeast Asia National Regulations (Sadovy 2000)

People’s
? Limits the number of grouper “seed” fishers and the quantities of grouper “seed” captured
Republic of China
? A licence is needed for transporting marine “seeds” and their export is prohibited
? There is a management regulation of Guangdong Province for the cultivation of aquatic products in the shallow sea intertidal zone, which applies to those engaged in marine cultivation
Hong Kong
? Culturists must be licensed and operate in one of 26 gazetted culture zones
SAR China
? There are no regulations that apply to the capture of grouper “seeds” or their import or export
Indonesia
? There is no management of seed resources
Malaysia
? Federal legislation prohibits the use of cyanide for fishing
? In East Malaysia there are no special regulations for grouper seed capture. Some regulations may act indirectly, for example some gears that are made of trawl net are subject to trawl mesh size control. Grouper seeds cannot be imported for culture
? In West Malaysia the fishing of “seeds” is not allowed during November and December; it is only permitted during the peak season from January to April. No export of seeds smaller than 15 cm is permitted
Philippines
? It is illegal to use cyanide or any other poisonous substance for fishing
? Scissor nets are illegal
? Fyke nets have been banned
? The Fisheries Code of 1998 (Republic Act 8550) prohibits the export of “seed” of milkfish and prawns but its application to groupers is not clear. This Code regulates gear/structures and operational zones for fish capture and culture
? Transportation and export of fish and fisheries products requires permits from the Quarantine section, including a health certificate from the Fish Health section of BFAR
Taiwan Province of China
? In Penghu Island, fisheries are not permitted to catch any grouper seed of <6 cm
? The use of cyanide for fishing is illegal
Thailand
? The use of push nets and fyke nets is limited. Push nets and trawlers should not be used within 3 km of the shore and the mesh size of trawlers should be ?2.5 cm
Viet Nam
? Government regulations prohibit export of groupers <500 g (Ministry of Fisheries)
? There is no limit on export volumes. For export a health certificate from a provincial office, Fisheries Resources and Environment Conservation Sub Department is needed, and requirements of the importing country satisfied

 

International Agricultural Research (ACIAR), and the WorldFish Center (formerly known as ICLARM), etc. 1998 saw the establishment of the Asia-Pacific Grouper Network (APGN); this organization aims at aquaculture development, in order to:
? reduce the current reliance on capture-based “seed” for aquaculture, as the capture of wild juveniles is sometimes carried out using destructive fishing techniques that can have significant impact on the long-term status of the stock;
? provide an alternative source of income/employment for coastal populations currently engaging in destructive fishing practices;
? protect endangered reef fish from the pressures of illegal fishing practices, through the development of sustainable aquaculture;
? develop new aquaculture livelihood options and investments that will generate economic benefits for a diversity of stakeholders and employees.
Since 1996, all the above mentioned organizations have set up workshops, with the aim of establishing a regional mechanism for research cooperation that supports the sustainable development of capture-based aquaculture in the Asian region. Emphasis has been placed on technology transfer and management strategies for the benefit of farmers and coastal populations.

Conclusions

The complex interactions of capture-based aquaculture with fisheries and aquaculture pose many difficulties. There is a need to develop specific rules that complement existing regulations in order to improve management practices. Management schemes for capture-based aquaculture need innovative instruments and concepts. Overfishing, bycatch, gear selection, etc., are common problems concerning resource removal. Environmental impacts (waste, eutrophication, etc.) are problems that are shared with other aquaculture systems. However, in addition, capture based aquaculture practices have their own specific characteristics, such as “seed” importation, the transhipment of live fish in open seas, the unloading of catches, food quality, unspecific diets for feeding (mostly trash fish), etc. Other complexities are species-specific; some examples are the towing-cage transportation of tuna, the wastage of “seed” arising from unnecessary mortalities during harvest, transport and culture, and the problems linked to the export/import of capture-based “seed”.
Most of the concerned management authorities (either at national, sub-regional, or regional levels) having to deal with capture-based aquaculture systems are working to assess the dimension of the issue, in efforts towards identifying adequate responses. For example, at a regional level, ICCAT and GFCM are considering potential solutions to integrate northern bluefin tuna capture-based aquaculture within a coherent management framework in the Mediterranean area. As an example of actions at a national level, the Japanese Coastal Fishing Grounds Rehabilitation and Development Law, enacted in 1974, creates fish shelters to attract fish to new fishing grounds and promotes the release of fry into coastal waters for culture-based fisheries. A fishing rights system authorizes local cooperatives to manage the fisheries in coastal waters, and a special license is required to collect and sell the fry of yellowtails, to prevent overfishing.
With regard to the management of groupers, one possible approach is, as Sadovy (2000) suggests, the establishment of nursery areas where the capture fishery and culture operations occur. Another possibility is to protect key “seed” settlement areas and nursery habitats, such as mangrove areas and sea-grass environments in river mouths and estuaries, and to ensure “seed” production by safeguarding spawning adults. Protected marine areas may incorporate key settlement and nursery areas.
For all capture-based farmed species it is important to study not only the biological characteristics (spawning capacity, behaviour, etc.) of both the wild and farmed fish and to carry out specific research, but also to understand all of the impacts and monitor all the parameters related to these practices, particularly the social, economic, and environmental parameters. The need to develop policies and a legal framework for capture-based aquaculture is now widely recognized. As capture-based aquaculture is a practice which is constantly developing (mainly for high commercial market value target species), care should be taken to create or amend the comprehensive regulatory framework to ensure that the sector develops in a sustainable manner. In particular, legal and institutional instruments should continue to be explored and developed, inter alia, to:
? recognize capture-based aquaculture as a distinct sub-sector;
? integrate capture-based aquaculture concerns into resource use and development planning;
? improve food safety and quality to safeguard consumers, and meet the standards of importers;
? improve the management of capture-based aquaculture, particularly where the practice is potentially unsustainable (e.g. due to overfishing, bycatch, food wastage, the use of trash fish, and the relationship between the consumption of raw fish and consumer safety).
Specific actions might best be taken through international agreements or arrangements among the countries that share the same resources. Related measures could include acceptable capture methods for “seed” and market-size fish, seasonal or other bans to protect specific size classes or species, and restrictions on numbers and sizes taken. For the responsible management of capture-based aquaculture, it would also be advisable for governments to consult and permanently interact with private farmers, in order to identify factors that may be inhibiting sound management and development; the principles set out in the CCRF and the Draft Code of Hygienic Practice for the Products of Aquaculture could provide useful guidance.