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Doc. 8464

9 July 1999

Challenges, advantages and development of extensive aquaculture

Report

Committee on Agriculture and Rural Development

Rapporteur: Mr Fernando Gonzalez Laxe, Spain, Socialist Group

Summary

Extensive aquaculture includes systems of culture and rearing in which human intervention is concentrated on reproduction of the stock in addition to capture. Compared to fishing, these systems make it possible to selectively increase the production of the species most in demand for man.

From the ecological standpoint, the potential for expansion of extensive aquaculture appears considerable, especially as European countries as a whole are faced with both a quantitative and qualitative shortage of sea products. The results have been disappointing however. In view of this, public policies should continue to support the expansion of aquaculture and the diversification of production systems.

The main obstacles seem to be legal and institutional (livestock ownership arrangements, conflicts due to competing uses of the maritime area). But programmes should also be launched with a view to demonstrating the ecological and technical feasibility of extensive aquaculture as well as its economic advantages. Different proposals are put forward in this report.

I.       Draft resolution

1.       The Assembly has always taken an interest in food security questions, including problems concerning fishing, an activity that is important not only in terms of food but also for social and economic reasons.

2.       It is now clear that the growing demand for a comparatively cheap resource such as fish has led to an over-exploitation of stocks which is in the process of exhausting them by jeopardising their renewal.

3.       It has also been acknowledged that aquaculture is potentially able to provide a partial solution to these problems, both quantitatively by ultimately making good the food deficit and qualitatively by enabling natural populations to be preserved. It must be noted, however, that although aquaculture offers promising prospects and has undergone considerable expansion over the past ten years (averaging an annual growth rate of 10% and accounting for 25% of total production), this sector is still suffering from a lack of knowledge and investment, particularly as far as extensive aquaculture is concerned. The fact is that the image of aquaculture, which is a more environment-friendly activity capable of producing more natural kinds of food, could be enhanced.

4.       The Assembly is convinced that it would be fully in the interests of public authorities to increase their support for aquaculture and for the diversification of production systems, especially with regard to species of high commercial value. Europe currently has a deficit of fishery products (8 billion euros in 1998 for the European Union alone) and is a net importer to the tune of more than 20 billion euros.

5.       It may be observed, however, that extensive aquaculture is still encountering difficulties that impede its development, particularly as regards vagile (non-sedentary) species and chiefly in two fields: technical restrictions (notably with regard to livestock breeding and feeding) and legal regulations (above all with regard to livestock ownership arrangements and conflicts due to competing uses of the maritime area).

6.       Public authorities, whether national or European, have an important part to play in the development of knowledge permitting improved planning as well as rationalisation and optimisation of extensive aquaculture systems (ecology, zootechnics, economics, law, halieutics). Large-scale research programmes of an integrated and pluridisciplinary nature are needed, and the requisite substantial funds can be raised only by the public sector, which can also provide a guarantee of the neutrality and public interest of such research.

7.       Among the problems still hindering the development of aquaculture, emphasis should be placed on the unavailability of inshore sites for the establishment of new farms as well as the competition with other already-established or traditional uses (fishing, tourism, protected areas, etc.). These conflicts are indicative of the inadequacy of the present methods of allocating the marine area between competing uses.

8.       With regard to the ownership of stocks, problems arise when it comes to replacing public financing and exploitation systems by private ones (whether individual or corporate). With regard to extensive fish farming, private ownership and exploitation are still the exception. Privatisation of stocks may thus be seen as a decisive factor, but it requires some preliminary clarification regarding systems for regulating access to the resource and arrangements for allocating and exchanging rights.

9.       The new conditions of access to natural resources (new regulatory arrangements) call for an institutional reform, which may be expected to encounter different obstacles. The Assembly is convinced of the priority need for such a reform, which it regards as part of the political process and dependent upon official action.

10. Accordingly, the Assembly invites member states and the European Union:

i.       to rationalise extensive farming systems by making a single authority responsible for fisheries, the management of natural resources (in particular, adjustment between the volume of the biomass and the capacity of aquacultural ecosystems), the development of exclusivity regimes and the rationalisation of uses;

ii.       to adapt national and community legislation so as to clarify exclusivity systems by clearly distinguishing functions connected with the ownership of natural resources from those relating to rights of use, for which economic allocation arrangements are proving more effective;

iii.       to improve the regulation of access to fisheries, the legal status of stocks and the plundering of stocks by external fishermen, as well as ensure a better match between public costs and private earnings;

iv.       to envisage the introduction of fish resource privatisation schemes and study the merits of the various ownership arrangements (public, corporate or individual), embodying them in legislation if appropriate;

v.       to increase the effectiveness of official action by decentralising the management and planning of fisheries at both national and community level;

vi.       to create, for that purpose, independent public agencies supervised by authorities comprising representatives of responsible administrations and users' groups and responsible for evaluating resources, allocating rights of use, monitoring the exercise thereof and financing natural resource enhancement programmes;

vii.       to include the regulation of aquaculture systems and the conservation of the environment in the study of the reform of fishery regulation arrangements;

viii.       to instruct the competent national research centres to initiate studies with a view to demonstrating the ecological and technical feasibility of extensive aquaculture as well as its economic advantages, and in particular :

a. to carry out pluridisciplinary research programmes concerning the development of extensive aquaculture, with particular reference to the diversification of sedentary species and the collective exploitation of vagile species, while giving priority to species of greater commercial value;

b. to develop research in such fields as systems for regulating marine populations (ecology of juveniles, breeding strategies, etc.), the planning of fisheries, the domestication of living resources (choice of stocks, homing behaviour, etc.), measures to combat the colonisation of exotic species (hybridisation, risks to wild populations) and the conservation of the environment (pollution, health hazards, etc.);

11.       The Assembly also invites the Food and Agriculture Organization (FAO) and its Committee on Fisheries, the Organisation for Economic Co-operation and Development (OECD) and its Fisheries Committee, and the International Council for the Exploration of the Sea (ICES) to take note of its proposals, study them, and launch research programmes with a view to permitting the development of extensive aquaculture and contributing to that of the fisheries sector in general.

II. Explanatory memorandum by Mr Gonzalez Laxe*

Table of contents

1. Introduction ………………………………………………………………………….       6

2. The main extensive systems …………………………………………………………       8

3. Conditions required for the take-off of new extensive systems ……………………..       18

4. Rationalisation of mature systems ……………………………………………………       24

5. Exogenous factors ……………………………………………………………………..       30

6. Conclusions …………………………………………………………………………….       35

References ………………………………………………………………………………………       40

Appendix 1:        Main shellfish farming production in Europe …………………………………..       42

Appendix 2:        List of European marine species whose reproduction is

* The Rapporteur and the Committee on Agriculture and Rural Development would like to thank Professor Jean-Paul Troadec for his valuable co-operation and his outstanding contribution to the preparation of this report.

1 - Introduction

Extensive aquaculture includes systems of culture and rearing in which human intervention is concentrated on the reproduction of the stock, in addition to capture (Lockwood, ed., 1991; Howell and al., eds. in press). As compared to fishing, these systems make it possible to selectively increase the production of the species most useful for man’s food (salmon, oysters, etc.), industry (algoculture), or pleasure (sport fishing, pearl culture, etc.). They use the planktonic or benthic production of the water masses, thus economising on the fertilisation of the breeding environment (semi-intensive systems), or the fattening of the stock (intensive systems).

Extensive practices are not new. In Europe, the fattening of mussels on stakes dates back to the 14th century. The value of capturing spat as a remedy for the overexploitation of natural oyster beds was realised as early as the second half of the 19th century. The value of transplanting young plaice from their nurseries in the south of the North Sea to less densely populated lagoon or sea fattening zones, at the beginning of this century. The mastery of artificial reproduction stimulated enthusiasm for sea ranching: the first releases of young salmon from hatcheries date from the middle of the last century (Europe, Pacific coasts of America and Japan), the first cod hatchery was built in Norway in 1884, and the first lobster hatchery in 1891 on the Atlantic coast of Canada …

Knowledge about the actual production of several extensive systems is still limited. While the production of sedentary species (shellfish and algae), whose stocks are geographically distinct from the natural beds and generally owned by an individual or a corporate body, is fairly well known, the culture of vagile species (mainly fish and crustaceans) whose stocks are exploited collectively at the same time as wild stocks and whose captures are not distinguished from those of the natural populations, is not at all well known. This uncertainty has led the FAO to exclude from its aquacultural statistics the production of collectively exploited stocks 1. This decision leads to the inclusion in the fisheries statistics of production resulting from the release of young fish into water courses, lakes, coastal waters, and the ocean, even though this production is very significant for several species, in particular salmon.

Algoculture and shellfish culture, with a production of 7,7 and 7,3 million tonnes respectively in 1996 (FAO, 1998a), based almost entirely on the extensive modes, represent half of world aquacultural production as defined by the FAO. European shellfish production exceeds 750,000 tonnes (Appendix 1). In Japan, the production of chum salmon by ranching has increased tenfold over the past thirty years, to exceed 200,000 tonnes today. In 1994, the number of migrating fish in the rivers of Hokkaido was ten times the previous maximum observed in the entire history of fishing (Kobayashi, 1980; Kitada, in press).

From the ecological standpoint, the potential for the expansion of extensive aquaculture appears considerable. Theories on the reproduction strategies of aquatic populations, the amplitude of the natural fluctuations of wild populations, and the productions achieved in certain extensive farming systems indicate that aquatic ecosystem could support stocks far bigger than the average biomass of the wild stocks. Furthermore, since the volume of the marine ecosystems exploited by these methods is still relatively small, it is understandable that this mode of production should stimulate research interest. The number of marine species studied rose from 150 in 1984 to 250 in 1994 (Lacroix et al., 1998).

The results have been disappointing however. In recent years, few R&D programmes have led to any significant production. Shellfish culture is experiencing overstocking problems which are resulting in the deterioration of the technical and economic performances of the enterprises concerned. In the effort to reduce these imbalances and manage the conflicts which result from the competing uses of coastal ecosystems, traditional methods of regulation have proved ineffective.

The prospects for extensive aquaculture can be evaluated with reference to the state of the sector (FAO, 1997). Since the 70s, the annual rate of increase in world halieutic production has constantly been falling - in value terms even more rapidly than in tonnage -, to become negative in the course of the this decade. The reason for this decline is the exhaustion of wild stocks and the ineffectiveness of the traditional methods of regulating access to fisheries whose possibilities for expansion are exhausted2. The aquaculture development policies introduced at the end of the 60s to take over from conventional fishing started to bear fruit during the 80s. For the past fifteen years world aquacultural production has been growing at an annual rate of 8.5 %. It now accounts for over a quarter of total production (FAO, 1997). Progress remains unevenly distributed however in terms of cultivation systems, production regions, products and markets. Despite the spectacular success of salmon farming in northern Europe or prawn culture in the tropics, traditional systems (small shellfish farms, fresh-water fish farms, and algoculture, mainly in Asia) remain the main beneficiaries of the new expansion. Due to the stagnation of fishing catches, European countries as a whole are faced with both a quantitative and qualitative shortage of sea products. In 1996, they imported over US$ 21 billion of sea products, and the deficit amounted to US$ 6 billion (FAO, 1998b). For the European Union alone, it was US$ 8 billion - and respectively US$ 16 billion and US$ 4 billion for Japan and the USA (FAO, 1998b). Only Norway, Iceland, Russia, Denmark, Ireland and Ukraine are, in descending order, net exporters in value terms. As in most of the rich countries, the shortage was mainly in high quality products (noble fish, crustaceans and shellfish, fresh, filets and frozen). In these conditions, public policies should continue to support the expansion of aquaculture and the diversification of production systems, with priority being given to those concerned with species of high commercial value.

The marine environment is well suited for the analysis of the implications and possibilities of extensive aquaculture. Because of their large dimensions, and because, even in coastal areas, the seas and oceans suffer on average less pressures than inland waters, marine ecosystems offer better prospects. The scale of the oceanic masses reveals better the problems that the fluidity of the milieu and the mobility of the stocks represent for their domestication. Any advance in the law of the sea sheds better light on the role of the institutions in the exploitation of natural resources and the rationalisation of their uses.

This document starts by describing extensive aquaculture, then presents the main variants (section 2). The take-off conditions for new systems (section 3) and the rationalisation of mature systems (section 4) are then examined. Section 5 reviews a number of exogenous factors (conservation of the environment, demand, public intervention) likely to affect the development and optimisation of extensive cultivation. The last section (6) summarises the prospects, the conditions for the success of R&D programmes, and the requirements for the rationalisation of this mode of production.

2 - The main extensive systems

2.1 - The process of domestication

Technical intensification makes it possible to exceed the productivity limits of the wild stocks. The process consists of extending the technical controls of physiological functions such as reproduction, particular stages of the life cycle (eggs and larvae, juveniles, adults, reproducers), as well as their cultivation milieus. This domestication takes place through discrete jumps: between fishing and completely controlled cultivation there is a range of systems that can be classified in four groups: (i) those which concern essentially reproduction, (ii) those which also intervene in the fertility of the cultivation milieu, (iii) those in which the stock is also fed, and (iv) lastly, those in which the wastes are also recycled3. Not all of the technically conceivable systems are viable, and the most intensive are not necessarily the most efficient.

While technical intensification reduces the role of the natural resource, it does not eliminate the dependence of production vis-à-vis the environment. It changes only the nature of the constraining factors and the limits that they impose on production. In fishing, it is the tertiary production - that of the halieutic populations - which is the limiting factor. In aquacultural systems, the stock, which is artificially reproduced, is no longer limiting. It no longer constitutes the natural resource. Appropriated, it becomes assimilable to capital. In extensive cultivation it is the primary and secondary productions (plankton and benthos) serving as food for the stocks which limit production. In intensive systems where the food is added it is the wastes (unconsumed food, faeces, antibiotics and medicines, etc.), as well as escapes of individuals who may modify the genetic heritage of the wild populations, that need to be adjusted to the acceptance capacity of the aquatic ecosystem. Throughout the process of domestication, the capital and labour intensity of the operation increase at the same time as the technical intensification. The increase in productivity (per unit of area) thus obtained is accompanied by an increase in the pressure on the environment.

In the course of this process the economic and social organisation of the operation also changes. As the technical controls diversify, the rules which define and support their exercise - and in particular the regimes governing the ownership of the natural resource - change. Mazoyer and Roudart (1997) thus describe the links which have developed in agriculture between the domestication of the natural resources, the intensification of their exploitation, and the land ownership regime: ‘It emerges from this long history that, since the Neolithic age, the “ownership” of the land has gradually extended to the different categories of land as they have become artificialised: built on land first of all, then gardens and enclosures enriched and cultivated each year, cleared land bearing crops, developed hay meadows, land cultivated between two uncultivated or fallow periods, land cultivated continuously, improved pastures, developed and maintained forests. The ancient rights of common use (hunting, gathering, gleaning, use of the common, right to collect wood), for their part, have always concerned land where, without any particular work, wood, natural grasses, the wild grasses of fallow land, game, etc. continued to develop spontaneously” (italicised by the authors). The history of shellfish culture in Yerseke in the Netherlands (van Ginkel, 1991) shows that the processes in aquaculture do not differ fundamentally from those observed in agriculture. In the course of the process of technical intensification, the structures of the production, exploitation and regulation systems4 were transformed in stages:

1.2 - Description of extensive aquaculture

Extensive aquaculture is characterised by a production function in which human intervention is concentrated on the reproduction of the stock (fig. 1). This intervention may take two forms:

Figure 1 - Schematic representation of extensive aquacultural systems

The first set of examples shows that artificial reproduction is not essential to start a new system. On the other hand, the capacity to act on the reproduction of a population through forcing its recruitment5 is.

As the stock feeds on the natural milieu, extensive fish farming is sometimes qualified as ‘production’, as opposed to intensive fish farming, qualified as ‘processing’ in which artificial feeding is provided. In the sea, semi-intensive systems in which at least part of the food is produced in the cultivation milieu do not exist (outside lagoons). This is not the case in agriculture or fresh-water fish culture. This difference is explained by the fluidity of the aquatic milieu and the scale of the water masses which limit the possibilities of fertilisation to units of sufficiently reduced dimensions - hence inland (ponds, lakes and lagoons) -, and also by the state of ownership regimes in the maritime field. In the sea, the ownership of stocks is limited virtually exclusively to sessile or sedentary species (shellfish, algae), and vagile species (fish) in captivity (fish culture in cages or basins). The importance of intensive cultivation in the marine field is perhaps due as much to the need for the appropriation of the stock as to the enhanced zootechnical performance.

Extensive systems which aim at fattening naturally result in overpopulation (as compared with the biomass observed under natural conditions). The increase in biomass – and hence finally in the total production of the stock - is limited by the trophic capacity of the ecosystem used as the cultivation milieu. The growing tension between the biomass in expansion and the limited productivity of the cultivation milieu results in a regular decline in yields (decline in growth performance, increased mortality and increased risk of epizootic diseases).

Extensive cultivation does not modify the environment very much. However, the employment of selected strains for the purposes of cultivation or exotic strains for the rearing of young fish risks impairing the genetic heritage of the wild populations living in the same ecosystems.

Recapture is facilitated when the stocks are made up of sessile or sedentary species, or when fishing is carried out close to the coast or in rivers where the stock concentrates periodically (salmon during their reproduction, for example).

Like halieutic stocks and intensive cultivation, extensive aquaculture is subject to the effects of pollution by industrial, agricultural and domestic wastes. The fluidity and density of aquatic milieus makes them more sensitive than land and atmospheric milieus. Aquatic milieus are in fact better carriers than land and atmospheric milieus, and leaching and transport by water course networks concentrate the greater part of the residues from human activities in the catchment areas in the rivers and coastal areas. On the world scale it is estimated that some 70 % pollution ends up in the sea.

2.3 – The main extensive systems

Physical development of habitats

A halieutic population can be supported by the development of habitats critical for its reproduction. This is the case, for example, with ladders to enable salmon to get past dams on the rivers they use for their reproduction migration, arrangements to conserve the flow and quality of river water, or the maintenance of their fry ponds.

Artificial reefs are the most common example of physical measures in the marine field (Jensen, ed., 1997). It is in Japan, where it is planned that they will cover 12 % of the coastal areas by the year 2000, and along the Mediterranean coasts in Europe, that these arrangements are the most developed.

Their promoters attribute the following virtues to artificial reefs:

Depending on the objective, the species it is desired to support, and the fishing methods it is intended to favour, the materials and architecture of artificial habitats vary considerably.

In the creation of artificial reefs, the exclusion of non-indigenous species by residents preoccupied by the rarefaction of natural resources in the sectors that they are accustomed to frequent is often an important motive, even though it is not always expressed. This monopolising of space may facilitate initiatives in favour of conservation. In the USA, for example, artificial reefs are used to increase the floral and faunal richness and promote the development of ecological tourism. The example of floating rafts and other arrangements to concentrate fish shows that these constructions can effectively attract fish. Through bringing the fishing grounds closer, stabilising the presence of the fish and facilitating the spatial allocation of fishing sites, artificial reefs can aid fishing and its regulation. But the same results can also be achieved by other methods, possibly less costly (floating rafts), or more direct (shellfish culture).

The effect of artificial reefs on the production of halieutic stocks remains to be demonstrated. Up to now, the observations have virtually exclusively been concerned with spot densities of adults, whereas to demonstrate the impact of the reefs on halieutic productivity it would be necessary to be able to measure their effect on the absolute abundance of the populations. This implies studying the process of regulation, on the scale of the population, and at the level of reproduction and the early stages where these processes act (§ 3.2). While such studies may be complex and costly, they are nevertheless realisable. Only such investigations would make it possible to establish whether artificial reefs are the best way of achieving the objectives assigned to projects for the implantation of reefs and, if this is the case, the conditions that must be fulfilled (nature, localisation, extension) to obtain the best impact. Artificial reefs, for example, are likely to effectively support the recruitment of halieutic stocks provided that they cover a sufficient proportion of the coastal nurseries. On the other hand, through acting on the effects (stocks) and not on the causes (regulation of access) of overfishing, they can at best retard, but not prevent, overexploitation.

Shellfish culture7

In shellfish culture, the forcing of recruitment is achieved in different ways:

The more or less complete mastery of recruitment has permitted three major advances:

Thus, a rustic production chain, not initially requiring the complete mastery of the biological cycle, has turned out to be economically efficient and well adapted to the exploitation of particularly productive coastal ecosystems. This development has taken advantage of three particularities of shellfish ecology:

But the take-off of the system was achieved only because these technical advances were complemented by institutional innovations:

Shellfish culture has been developed above all in Asia (China, Korea, Japan, etc.) and Europe (Appendix 1). In France, for example, the shellfish culture turnover amounts to over one-third that of fishing and employment is one and a half times that of fishing. The big differences seen in European production, both between countries and between species, suggest that the constraints which impede the development of shellfish culture are social and institutional rather than ecological or technical. There should therefore be possibilities for expansion in countries where production is still modest.

90% of European production is accounted for by oysters and mussels. While both oyster and mussel growing have been modernised in recent years, Europe has not achieved any successes comparable to that of Asia with the development of the cultivation of the Japanese scallop (Pecten yessoensis). Mastered in Japan at the beginning of the 50s, production reached a million tonnes in China and 265 000 tonnes in Japan in 1996 (FAO, 1998a). There are nevertheless prospects for diversification in Europe. The cultivation techniques of several species have been mastered, but the take-off of commercial production comes up against various difficulties: ecological and economic for the abalone (Haliotis tuberculatus), epizootic (brown ring disease) for the Philippines clam (Ruditappes philippinarum), and legal for the scallop (Pecten maximus; § 3).

Sea ranching

While, as with the sedentary species, the fattening of vagile species is possible in the marine milieu, their mobility seriously complicates the appropriation of the stocks and the captures. The systematic marking of hatchery products is made difficult by the small size of the individuals. Above all, it is difficult to ensure that the ownership of the stocks is respected at sea because of the remoteness of the fishing areas and of the low density of boats on them, as well as the transitory nature of the catches. This is why the ownership of stocks of vagile species is practically never acknowledged at sea. Contrary to what happens with livestock in agriculture, fish that escape from private farms become public property.

For certain species these difficulties have been partially overcome by the exploitation of a trait common to many aquatic populations, the phenomenon of homing (§ 3.2). Through choosing species which congregate to spawn in coastal or inland waters where access to fishing is restricted and easier to control, enough of the stock can be recaptured to cover the cost of rearing the fry. Sea ranching is based on this strategy. Technical success is assured if the weight gain in the individuals recaptured during the fattening phase exceeds the combined losses due to natural mortality, straying – not all individuals return to the point where they are released -, and catches by third party fleets. When these conditions are fulfilled sea ranching offers the possibility of harnessing the unexploited primary and secondary productivities of vast maritime areas.

The risk of interception by third party fleets increases, on the other hand, with the area and duration of the freedom phase. The salmon ranching programmes of the Baltic countries (mainly Sweden and Finland) have been so successful technically, for example, that they have given rise to the development of plurinational fishing at sea (Ackefors et al., 1991). The captures have reached such a level (some 3,000 tonnes, or 80 to 90 % of the annual recruitment) that they are now threatening the wild stocks fished at the same time. Through ensuring the profitability of fishing, a rearing programme intended to conserve the natural populations decimated by hydraulic schemes and river-borne pollution is now threatening their survival. The answer would be to prohibit fishing at sea. This is the solution adopted in the North Pacific where the states have agreed to prohibit salmon fishing on the high seas, or in Iceland where salmon fishing has been prohibited in coastal waters for the past 60 years.

The system was first developed for salmon (Isaksson, 1988). For these species in fact, ranching offered a solution to the crucial problem of the conservation of populations threatened by the degradation of their inland water habitat on which they depend for their reproduction and in which they are particularly vulnerable. Salmon exhibit a number of traits that favour this type of enterprise:

For a long time the impact of the experiments carried out in the Atlantic and North Pacific was nil or not proven. It was not until the 60s that, simultaneously in Sweden and the USA, the technical viability of the method was able to be established. Since then, advances in knowledge have revealed the critical importance of factors which had been neglected for a long time, such as the marking and identification of hatchery individuals in catches for the evaluation of survival rates and conditions, or the risk of genetic mixing or pathological contamination with wild populations, etc. Since then the list of first technical and then economic successes has lengthened. In the literature, the turbot in Europe (Hoffmann, 1991), and the gilt-head bream (Pagrus major), the flounder (Paralichthys olivaceus), the chum salmon (though perhaps no longer since the development of fish farming in cages has brought prices down) and the Japanese prawn (Penæus Japanicus) in Japan (Kitada, op. cit.), are cited among the species whose production by ranching is considered economically viable. On the other hand, in Europe, research into lobster (France, United Kingdom, Norway) and cod (Norwegian PUSH8 programme) reached negative conclusions.

The interest of sea ranching is not limited to the conservation of marine fauna. The technique may meet three objectives mentioned in section 2.2:

The long history of transplantation of young plaice in the North Sea (Rosenthal, 1978; Hoffman, op. cit.) is worthy of mention. Launched in 1891 in Denmark and pursued for over a century, the programme has been extended to other species (cod, salmon, trout, whitefish, turbot and eel), and repeated in other countries (Germany, United Kingdom, Norway and Sweden). Although their technical efficiency has been demonstrated and economic profitability has been achieved in several configurations, these programmes have never given rise to significant commercial development. The reasons for this relative failure are political and financial. In Denmark, for example, the programme gives rise to disputes over the ownership of the stock. Fishermen of the coastal regions of the North Sea where the juveniles are fished claim they should conserve rights over the transplanted stock, just as the Limfjord fishermen, even though no professional fisherman contributes to the financing of the transplantation. Only the sports fishermen of the Limfjord pay a fee, and this represents only a small proportion of the total cost. In these circumstances, no significant private financing is going to take over from the public funding which for its part remains modest.

The organisation and management of ranching programmes differs according to the objectives. Programmes which are limited to the conservation of wild populations, without concern for profitability, are most often implemented by public bodies, even though the production of the young fish is sometimes subcontracted to private fish farms. The creation of significant stocks involves two questions: the reservation of their exploitation to particular groups (groups of national and local fishermen, professionals or anglers), and the contribution of the main beneficiaries of the catches to the financing of the breeding farms. The state of Alaska, for example, grants licences to private hatcheries for non-profit operations which are managed by local cooperatives and communities of native fishermen exploiting the stock. Fishermen can pay a fee for the financing of breeding programmes. This is the case in the United Kingdom, where the landowners finance fish rearing programmes and then rent the fishing rights on their reaches to anglers. In Japan, professional fishermen pay a contribution calculated on the basis of the sales price of the fish (3 to 5%) to finance coastal breeding farms, while access to the coastal fisheries requires belonging to a cooperative or a group of private fishermen. Certain countries (Iceland, Chile and, in the USA, the states of Alaska, Oregon, Washington, and California on an experimental basis, etc.) authorise the creation of farms whose aim is private production for profit. In most cases however, private ranching projects come up against the opposition of both professional and sport fishermen, as well as the general public, who object to the calling into question of public rights, the private exploitation of public resources, or the risk to professional fishing of a fall in fish prices.

Systems for retaining fish in open milieus or very large enclosures

In order to limit the losses due to the straying of fish and catches by third party fleets, attempts have been made to reduce the area of straying of the stock through conditioning juveniles before their release by emitting a sound signal during feeding. This training may facilitate the recapture of the fish. It is in Japan that experimentation is most advanced (notably for the gilt-head bream - Pagrus major)9. These trials started in the 70s, but have not proved very conclusive. The fish get used to the signal and gradually move away from its source. Though the idea is intellectually attractive, the method involves several unknowns which need to be clarified for each species and on each site:

In the present state of knowledge, the method appears to be essentially a refinement of already mastered systems. Focusing on technical innovation, it under-estimates the institutional reforms on which its success depends.

Stocks are also confined, or it is planned to do so, in large natural spaces (lagoons, bays) by physical means (dams, nets, electric screens, bubble screens, etc.). This method also underlies the valliculture traditionally practised in Mediterranean lagoons. It is very developed in Asia, traditionally in fresh waters, more recently in coastal zones. As compared with physical barriers, bubble screens or electric screens has the advantage of not being subject to fouling or the accumulation of debris (algae), nor to damage by bad weather. On the other hand, their effectiveness remains to be proven. Some people consider this to be the way forward for aquaculture, in so far as the method would permit the extension towards the sea of intensive systems whose development in the coastal zone is blocked by constraints of space and conflicts of use, or is likely to be in the near future.

3 - Conditions required for the take-off of new extensive systems

3.1 - Production of quality juveniles

Although the small size of the eggs of the great majority of aquatic species complicates artificial reproduction, hatchery techniques have improved considerably over the past thirty years. In aquacultural research, the mastery of this function has often been considered a priority, even if artificial reproduction is not always essential for start up extensive cultivation (cf. shellfish culture or the transplantation of young plaice). Today the range of species whose reproduction is well or fairly well mastered is relatively large (Appendix 2) and given present knowledge and know-how this list could be fairly rapidly extended in the future. The production of juveniles is thus not a major obstacle to the development of extensive aquaculture.

On the other hand, the interest of artificial reproduction (uniformity of the product, reduction of natural hazards, less dependence on seasons and genetic selection) grows with the development of extensive systems. Even if the potential applications are less diversified than in intensive cultivation, genetic selection may contribute to the fight against epizootic diseases, improve growth performance, or serve to mark the individuals released (to help evaluate survival rates or genetic mixing with wild stocks). But selection also creates risks for the integrity of the genetic heritage of natural populations (§ 4.5). At present, the lack of basic knowledge about the genetics of certain taxonomic groups, such as molluscs, is a constraint for selection.

3.2 - Forcing recruitment

For most of the species which have been the subject of prolonged experimentation there is an abundant literature describing:

But, even for a single species, the conclusions are not always very concordant. This is explained by the essentially zootechnical approach often preferred in R&D programmes. In the absence of appropriate knowledge on the ecology of juveniles and the reproduction strategies of populations in their environment, it is difficult to define the qualities that the alevins have to exhibit and the conditions necessary for their release.

The constraints of aquatic life - and in particular dispersion - impose complex demographic strategies on marine populations (Bakun, 1996; Sinclair, 1989). These strategies exhibit a number of common traits however:

These constraints mean that marine species are made up of populations which are distinguished by the succession of patterns of distribution and migration specific to the different stages of the life cycle, their demographic characteristics (average abundance, growth, natural mortality), and their genetic heritage. During the initial stages, the numbers in each population fall dramatically under the effect of environmental processes independent of the abundance of the population (effect of temperature on sexual maturation, gametogenesis and viability of the eggs as in the case of the scallop; drifting into inhospitable hydrodynamic structures where the young stages may either perish or survive but lose any chance of participating in the reproduction of the population, as in the case of several species of fish), and trophic processes depending on the density of the population (predation, famine).

These demographic strategies have very important consequences for the design of high quality research programmes:

As the ecological constraints change with the objectives, the success of the R&D programmes thus depends on the explicit definition of the objectives, the underlying hypotheses and the experimental protocols. These conditions are difficult to meet in projects where research and development are not clearly distinguished. With advances in knowledge about the reproduction strategies of marine populations and the interest shown by marine ecologists in the full scale ecological experiments constituted by programmes to develop extensive systems, as well as in the possibilities for experimentation on the ecology and physiology of reproduction offered by hatcheries, these aspects are now better taken into account in extensive aquaculture programmes (scallop in France, Norwegian PUSH programme on cod, etc.).

3.3 - Availability of sites

Competition for sites with already established uses of the coastal strip may be an obstacle to the implantation of new fish farms. Shellfish culture initially developed on the intertidal zone, in bays and basins whose shores were not particularly sought after at the time. In countries where shellfish culture has been implanted for a long time (Spain, France, Netherlands, etc.), a good proportion of the favourable sites have now been colonised. A limited extension of cultivation towards the open sea remains possible thanks to technical innovations (oysters cultivation in deep water, mussel culture on nets). Where it is well established, shellfish culture benefits from the advantage of its anteriority in the allocation of new concessions. This is not the case with new implantations (mussel culture on hurdles) which often comes up against the opposition of local residents. Environmental protection arguments may be put forward with greater force against new forms of cultivation than against traditional uses (fishing, agriculture). These practices reveal the weakness of current methods of allocating the maritime space between competing uses. The fact that several types of extensive cultivation (vagile species and deep sedentary species) make relatively little demand on the maritime space could be an advantage in regions where the coastal strip is very sought after.

3.4 - Biotic capacity of the ecosystems and water quality

While, for the reasons explained above (§ 3.2), the biotic capacity of ecosystem is generally not an obstacle for the start-up of new extensive systems, this observation is not an absolute rule. The productivity of the ecosystem is not sufficient everywhere to permit growth rates compatible with profitable shellfish farming. Urban and agricultural wastes may, within certain limits, remedy this poverty, just as certain clean-up programmes may reduce the productivity of certain shellfish farming basins.

More critical for the development of extensive aquaculture, and more particularly of shellfish culture, is the quality of the water (§ 4.2). Feeding through filtration and bioaccumulation in the food chain make shellfish farming stocks and products very vulnerable to any deterioration in the quality of coastal waters under the effect of urban, agricultural and industrial pollution (§ 5.1).

3.5 - Technical efficiency and profitability

To evaluate the technical efficiency of a new system, it is necessary to be able to identify the individuals when they are recaptured. Several marking techniques are used for this purpose: external and internal physical marks, genetic marking (Norwegian PUSH programme for cod), or morphological marking (in Japan, for example, hatchery products may have characteristic traits: special form of the nostrils of sea bream, black pigmentation of the blind face of flounder, etc.). The possibility of changes in the rules of access to the stock and the imposing of a contribution to the financing of alevin rearing may cause fishermen to under-declare the recaptures. With good statistics, the estimation of the impact of rearing programmes on the biomass of a population and the fishing yield does not present any technical difficulties. On the other hand, the segregation of the different causes of mortality and losses (natural mortality, excess mortality of the artificial stock, straying rate, captures by different fleets) may prove difficult.

The existence of a persistent shortage of sea products of high commercial value in the rich countries and the fact that the development of extensive methods is not generally any more difficult for noble species than for others are factors favourable for the development of extensive aquaculture. On the other hand the poor correspondence, frequent in extensive systems, between social and private costs and benefits is a major handicap. It is the primary cause of the apparently poor efficiency of many extensive aquaculture programmes, and of the frequently insuperable difficulties encountered in trying to move from public to private financing. Demonstration of the technical and economic viability of a new system rarely suffices to ensure its take-off.

In order for a programme to be profitable, it suffices in principle for the price of the fish recaptured to exceed the cost of production and recapture of the individuals released. The shortcomings of the exclusion regimes mean that catches by third parties have to be counted as losses (in addition to those due to natural mortality and the straying of individuals), whereas from the technical standpoint they correspond to gains. A not insignificant proportion of both the gains (benefits for the conservation of piscicultural fauna) and the costs (use of the natural biotic capacity, risk of genetic mixing, modification of the landscape, etc.) are social. The financing will be all the more difficult to transfer to the direct private beneficiaries the greater these external effects. This is why a simple financial analysis at the level of the enterprise is not enough to establish the economic and ecological value of a new system. A cost/benefit analysis on the scale of the programme as a whole is essential. It will gain from being complemented by a risk analysis at the level of the main actors concerned (direct beneficiaries and other users of the ecosystem).

3.6 - Ownership of the stocks

Examination of extensive systems (§ 2.2) reveals the existence of correlations between the economic and social organisation of the operation and the process of intensification similar to those described for agriculture. Virtually all restocking programmes for the conservation of the fauna are financed by the public sector and benefit the society as a whole without restriction. The same is generally true of breeding young fish to support commercial fisheries in which access remains largely open and free: it is almost always financed by public funds. A partial move towards privatisation is to be seen in sport fishing in which anglers enjoy exclusive rights – collective or individual -, in return for a contribution to the financing of the breeding programmes. Elements of two systems are found in traditional fisheries: even though fishermen may contribute, the cost of the restocking programmes is generally borne by the state, but in common law access is often limited by a system of collective territorial rights. The collective ownership regime existing in Japan provides a good example of this type of regime. Japan is one of the rare countries to have legalised the privileges that coastal fishermen derive from their anteriority of occupation of the coastal strip and exploitation of coastal stocks. Collectively, fishermen’s cooperatives and certain private groupings hold rights of quasi-ownership over halieutic resources. While they are not permitted to sell their rights, neither may the state withdraw these rights. This formalisation of the common law is not unconnected with the development of extensive aquaculture in this country. While private ownership and exploitation are the exception in the extensive cultivation of vagile species (private farms for exploitation for profit by the owner, or sport fisheries where access is governed by individual rights), they become the rule in shellfish culture, in which the stock is readily appropriable and effectively appropriated. The difference does not end there: shellfish culture is considerably more developed than the ranching of vagile species. While the statistics on this latter are disparate, the figures available show that national productions are often an order of magnitude lower than those of shellfish culture. Lastly, the private ownership of the stock is virtually the rule in intensive fish farms.

Counter-examples of programmes which, despite their technical success, have not led to commercial production, or whose the take-off is blocked by institutional constraints, are no less clear. In France, for example, where the extensive culture of the scallop is technically mastered and has been the subject of full-scale experiments financed by the public sector, the transfer of the cost of planting to private operators is progressing only slowly. The trade organisations accept the fact that fishermen should make a contribution, on a voluntary lump-sum basis, to the financing of a collective restocking programme, but they are opposed to the granting of collective concessions on natural beds – though these are on the face of it the most promising -, or to modulation of the individual contributions which would give fishermen rights of recapture proportional to their contributions. This would in fact result in the adoption of a system of tradable individual quotas to regulate access to the fishing of natural beds. The start-up of cultivation on individual concessions comes up against the scale of lump-sum charges applied by the administration for the cultivation of oysters and mussels. Would-be fish farmers consider that the scale in force is too high for starting up a new system of cultivation where the level of risk is still high (Curtil, 1996).

Thus the privatisation of the stock appears to be a determining factor for the process of intensification: from fishing to intensive cultivation, individualisation of exploitation (traditional groups, sport fishing associations, commercial fleet owners, private farms), technical intensification (conservation, fishing, extensive aquaculture, intensive aquaculture), privatisation of the stock (public, collective, and individual ownership), and passage to the monetary sphere (conservation, sport fishing, commercial fishing, aquaculture) all go hand-in-hand.

In primary production where the allocation of the factors is governed by elaborate systems of private ownership, the rights explicitly define the variables, the holders, the quantities, the offences and the sanctions. They are exclusive in the sense that all the gains and losses inherent in the exercise of a right fall to the holders of the right. They are combinable and for this reason tradable. They are technically applicable and effectively applied, since a right which is not applied is not a right.

The mobility of vagile species makes it impossible to simply transpose to extensive cultivation the solution adopted in agriculture and shellfish culture – i.e. the subdivision of the area - for the appropriation of the stock. However, a better coincidence between the distribution of costs and benefits may be sought by allocating exclusive quantitative rights of alevin rearing and recapture to producers. However the application of this system in cultivation where the same species is fished in the same areas comes up against a problem: the impossibility of distinguishing the cultivated or wild origin of the captures. This uncertainty implies that fishing and cultivation should be subject to the same system of regulation. But it is by no means certain that the increase in production expected from a new system of cultivation will suffice to convince fishermen, who have open and free access to the wild stocks, that it is in their own interest to adopt a system of quantitative individual rights.

The adoption of individual rights also raises the question of the choice of the allocation mechanism. With the opening up of rural societies to national economies, the systems of customary rights based on social control are gradually falling into disuse. The poor performance of traditional methods of regulation of access in commercial fishing illustrates the ineffectiveness of administrative regulation as a way of allocating a factor of production in a commercial activity. The advantages of tradable rights (determination of the price of fishing rights by direct negotiation between the parties) comes up against the opposition aroused by the adoption of this system for allocating factors hitherto allocated by non-market mechanisms, and objections of inequality resulting from the people’s different capacities for taking advantage of the new opportunities created by the adoption of a new system of regulation .

The evolution of ownership regimes and mechanisms for trading rights finally depends on the clarification of national jurisdictions which, at sea as on land, define and guarantee the ownership regimes for natural resources. While the new law of the sea does indeed grant states rights of quasi-ownership over the resources contained within their exclusive economic zones (EEZs), their authority remains diluted for the stocks whose area of distribution covers the EEZ and the high seas, and is shared for stocks whose area extends over several EEZs.

But for a few exceptions - that of Iceland in particular, which is distinguished by its geographical isolation and the initiatives that this country has taken to adjust the organisation of its fisheries to new conditions -, the present situation in Europe scarcely seems favourable for the extension of extensive aquaculture to vagile species. The great development of continental waters for the moment reduces the prospects for highly migratory species like salmon. In the majority of European fisheries, access to the resources still remains for the most part open and free. In the EU, the Common Fisheries Policy has so far paid more attention to the maintenance of the status quo and the minimisation of the immediate consequences for fishermen of the recurrent measures taken for the conservation of stocks, than to the clarification of the regime of ownership of the resources and the modernisation of the mechanisms for regulating access.

4 - Rationalisation of mature systems

The constraints that extensive systems come up against when they arrive at maturity differ in nature from those which impede their take-off. Because shellfish culture is one of the small number of well-developed systems, our examination of the opportunities and conditions for the rationalisation of mature systems will be based on this mode of production. But the conclusions are transposable to the other systems.

4.1 - Adjustment of the stocks to the biotic capacity

The hypothesis according to which the trophic capacity of the marine ecosystem should be able to support biomasses greater than those of wild populations (§ 3.4) does not permit us to predict an increase in the biomass supportable by the various aquacultural ecosystems. The recruitment level of a population and the biotic capacity of an ecosystem to support the juvenile and adult fractions of a population in fact concern different stages of the life cycle and result from distinct processes. Thus the example of shellfish culture shows that the aquacultural potential varies considerably from one coastal ecosystem to another. But whatever the trophic capacity of an ecosystem may be, it is always limited. The finite nature of the natural resource will become increasingly apparent as the biomass in cultivation increases, and will result in a progressive decline in yield growth.

Figure 2 - Marennes-Oléron basin (France): trend in annual production according to the biomass cultivated - Portuguese oyster ( ), Japanese oyster (∆) and Japanese oyster in Portuguese oyster equivalent (*) (after Héral et al., 1986).

It is thus that in semi-enclosed shellfish farming basins where the water is renewed only slowly, the primary productivity (microphytobenthos and phytoplankton) that the stock feeds on becomes an increasingly limiting factor as the biomass of the stock grows. For access to food for their stocks shellfish farming enterprises find themselves in a situation of competition analogous to that well known in fishing. The continuous movement of the water within a basin prevents the shellfish growers from separately adjusting their stock to the productivity of their concessions. To increase the share of the primary production of the basin that they appropriate they individually have an interest in increasing their stocks, despite the overloading of the basin and the overall decline in yields that this behaviour leads to. Thus, in the Marennes-Oléron basin (Figure 2), the maximum production – slightly over 40,000 tonnes - is obtained for a biomass in the order of 80,000 tonnes. With the Portuguese oyster, the total biomass reached 200 000 tonnes. Exactly the same process was repeated when the basin was replanted with of the Japanese oyster following the disappearance of the Portuguese oyster (§ 4.3). The overstocking slows the growth of the oysters - which has the effect of lengthening the fattening cycle (from two to five years) -, and increasing the general mortality rate (multiplying it by two or three). The resulting loss of income only reinforces the overstocking behaviour on the part of oyster growers.

4.2 - Preservation of ecosystems

In sectors where shellfish culture is very developed, the farms may modify the circulation of the water (hurdles) and the substrate (sedimentation by the biodeposits - faeces and pseudofaeces). The productivity of the sites may be affected. In the Bay of Mont St Michel, for example, the deterioration in performance has led the growers to adopt self-imposed limitation of the stocks (spacing of the hurdles).

4.3 - Epizootic diseases

The recent history of French shellfish culture illustrates the risk of epizootic diseases connected with the transfer of spat and shellfish between countries and between basins. Between 1967 and 1972, two viruses totally eradicated the Portuguese oyster stocks. Fraudulently introduced, the Japanese oyster is thought to have been the resistant vector of the infectious agent. Through reducing the resistance of the stocks, the overstocking of the basins was probably a facilitating factor, but not the cause of the epizootic diseases. The epidemics appeared, in fact, after peak production levels had been reached in the main basins (fig. 3).

Figure 3 - Epidemics and annual commercial production of flat, Portuguese and Japanese oysters (IFREMER data).

The propagation of diseases has been facilitated by transfers of shellfish between basins. In 1978 and 1982, the flat oyster stocks were hit in their turn by two epidemics whose economic and social consequences were catastrophic. Production fell from over 20,000 tonnes to just a few thousand tonnes. Enterprises had to change species and farming practices and were forced to concentrate. Marketing circuits were disrupted and changed to the benefit of the traditional producers of cupped oysters. For the Brittany region alone, the loss of turnover for the period 1974-82 has been estimated at 1.6 billion current francs.

While the replacement of the Portuguese oyster by the Japanese has made it possible for production to start anew, the present monoculture increases the risk of epizootic diseases, which is all the more serious in that at present there is no substitute species. The difficulty of treating stocks in farms where curative measures are possible only on the spat before its immersion or, with heavy handling costs, on adults in the fattening basins, and the weak advance of mollusc genetics, mean that health strategies depend essentially on prevention. Checks are carried out on imports and also on immersion, transfer between basins, and farming practices and the state of health of the stocks are monitored (§ 5.3).

4.4 - Introduction of exotic species

Despite these controls, exotic species are regularly introduced on the occasion of imports of spat and illegal immersion of shellfish before their commercialisation. The apparitions of non-indigenous are in fact concentrated around the big oyster growing basins: Hydroides ezoensis, Apitasia pulchella, Anomia chinensis, Balanus amphytrite, etc. on the Atlantic coast of France; algae Laminaria Japanica, Undaria pinnatifida and Sargassum muticum in the Thau coastal pond on the Mediterranean coast of France. These imports may also have helped propagate the shelf limpet (Crepidula fornicata) - a competitor of the shellfish stocks - and a type of periwinkle (Ocenebra erinacea) - a predator of the oyster. Similarly, transfers of fish between Sweden and Norway were at the origin of the introduction of a monogene, Gyrodactylus salaris, which has provoked the catastrophic decline of certain wild salmon populations (Halvasen and Hartvigsen, 1989).

As shown by examples of the fortuitous introduction of exotic species, the risk for biodiversity is particularly serious when the plantings concern non-indigenous species. There have been many transplantation experiments in the past: Pacific salmon on the Atlantic coasts of Canada and the USA, Russia, Chile, New Zealand, etc.; Atlantic salmon on the Pacific coast of Canada; Atlantic lobster in the Pacific; king crab from the Sea of Okhotsk in the Barents Sea; South African crawfish in the Channel; algae (Laminaria, Undaria, etc. ) from Japan or Macrocystis from the Pacific coast of America in the Channel, etc. The Japanese oyster (Crassostrea virginica) has colonised practically the entire northern hemisphere. To limit this risk, the International Council for the Exploration of the Sea and the European Consultative Committee for Inland Water Fisheries have published a code and a practical guide applicable to the introduction of non-indigenous species and to the transfer of stocks within the same country (ICES, 1983). These provisions are not binding however. The example of shellfish culture shows how difficult it is to ensure compliance with the regulations governing transfers once cultivation has reached a high level of development.

4.5 - Genetic mixing

Large-scale rearing and restocking programmes which are not rigorously planned may constitute a threat to biodiversity. Through diluting the demographic structures of a species, the invasion of an ecosystem by a common genome may reduce the genetic adaptability of the wild population and cause the disappearance of local populations. The risk depends on the survival and reproduction rates of the foreign individuals, as well as the hybridisation rate and competition of the exotic strains with the wild stocks.

The risk is higher with intensive cultivation, since selection is aimed at artificialising the genetic heritage of the stocks. In the salmon farms of northern Europe, escapes from fish farms in cages already commonly exceed the recruitment of the wild populations, and are capable of exceeding that of the sea ranching programmes: in Scotland and Norway, the escapes from cages are of the same order (2 million individuals) as the number of smolts deliberately released for sea ranching.

In the case of restocking with wild strains already present in the ecosystem colonised, the risk of genetic mixing is theoretically zero (Diagram 1). To conserve the biodiversity of the wild populations of anadromous species such as the salmonids, planting may also be limited to one part only of the rivers, the wild populations being conserved in the others. This is what is done in Ireland for trout and salmon. Restocking may also be practised with sterile animals (triploids), but the genetic manipulation of strains intended for human consumption does not have a favourable image in the eyes of the public.

Up to now there is little evidence of mixing between domestic stocks and wild stocks and the modifications observed are mostly minor. In a review of the knowledge available on the genetic impacts of hatchery fish on the wild populations of salmon and steelhead trout in the Pacific, Campton (1995) concluded in these terms: “Although widely accepted theoretical and conceptual arguments suggest that the direct genetic effects of hatchery fish on wild populations could be substantial and potentially detrimental, the empirical data supporting those arguments are absent or largely circumstantial.” The problem is that for a long time sea ranching programmes were conducted without regard to the identity of the populations, without first establishing the zero state of the genetic heritage of the wild populations, and without genetically marking the individuals released. Since then evaluations of the rate of mixing have been carried out with genetically marked populations, in particular on cod in Norway and trout in Ireland.

In the present state of knowledge, the risk is thus poorly understood. But the fact that public opinion is probably very sensitive to it is in itself a threat to the development of aquaculture. For this reason certain specialists put this risk at the top of the list of the impacts of intensive cultivation on the environment, ahead of organic wastes - faeces and unconsumed food -, antibiotics, medicines and antifouling paints used on the cages. In order to have precise instruments to measure and monitor genetic impacts on natural populations, the Convention on Biodiversity is now preparing an in-depth analysis of the risk created by sea ranching and intensive aquaculture.

4.6 - Ownership of natural resources

When an extensive cultivation system becomes mature, its rationalisation involves the adjustment of the biomass in cultivation to the trophic capacity of the ecosystem (§ 4.1). This adjustment has to be made on the scale of the entire ecosystem. This requires that the ownership of the ecosystem - the natural resource - should be clarified. To take an image from agriculture, the breeder should have exclusive rights over his livestock and its pastures in order to manage it properly. The transposition of this model to the sea comes up against to two difficulties, one technical, the other institutional (Figure 4):

The problem of the clarification of exclusivity rights thus arises at two levels: that of the ownership of the natural resource, and that of the right of use (§ 3.6). The problem can be analysed in same way for the other uses of the natural resource: fishing and intensive aquaculture. Only the fraction of the ecosystem used changes with different uses (§ 2.1).

Figure 4 - Linkages of ecosystems, populations and stocks, and production, exploitation and regulation systems in the uses of living aquatic resources.

The need for clarification of the ownership regime is independent of the identity of the holders of the rights, as of the mechanism for allocating the rights of use. If the regulation of uses is in the hands of a public administration, its efficiency will be reduced if the respective responsibilities of public sector and trade structures, of sectoral administrations (fishing, aquaculture, environment), and different levels of the politico-administrative structure (from local to international), are imprecise. Seen from this angle, the concept of ownership no longer appears as an absolute right over things, but as an assortment of exclusive rights formalised to exercise different controls, allocated according to the respective capacities of the holders (from individual to international) to exercise controls pertinent to the appropriate scales (Hanna et al., eds., 1996).

While the adoption of the EEZ constitutes a decisive stage in the adjustment of the institutions to new conditions, the new law of the sea remains insufficient to ensure the conservation of renewable resources, the development of new aquacultural systems, and the organisation of fishing. The major shortcomings concern:

- clarification of the exclusivity regimes:

5 - Exogenous factors

5.1 - Deterioration of the environment

Shellfish culture provides a good example of the conflicts which arise between extensive aquacultural systems and the utilisation of the carrying capacities of the milieu. These conflicts are not symmetrical. While shellfish culture modifies the environment very little, its localisation in coastal zones where the wastes of human activities accumulate, and the fact that the cultivated species feed by filtration, which concentrates any micro-organisms or toxic substances in the products, makes them very sensitive to any deterioration in the cultivation milieu. This vulnerability may be illustrated by the following examples.

The growth of the stocks and their state of health depend on the quality of the shellfish culture ecosystem:

Eating shellfish raw increases the health risk. Purification techniques are, in fact, efficient or sure only for microbial contamination, and not for chemical or biotoxin contamination. This health risk is also liable to lastingly affect the quality image of the products:

What determines the appearance of toxic bloom has not yet been established. These blooms appear naturally, in fact, but the apparent increase in their manifestations and the concentration of occurrences in the plumes of rivers lead to the suspicion that the origin must be partly anthropic.

5.2 - Demand

There is a considerable deficit of sea products in the majority of European countries, especially quality products. Given the high nutritive value (low calories, low fat and cholesterol contents) and taste quality of fish, the demand for these products in unlikely to fall. The deficit could even increase if European and world halieutic production continues to decline and if the supply from developing countries levels off. Given the predominance of fishing in the total supply and the time necessary for the institutional adjustments required in the organisation of fisheries, this scenario is very plausible. Even if the expansion of existing fish farms and the take-off of new intensive projects reduce the deficit, diversification will probably not go hand in hand with the increase in production, because intensification is generally accompanied by a reduction in the diversity of the species cultivated. The potential interest of extensive aquaculture should be viewed in this light. Technically, the method can be used to produce a great variety of species (shellfish, prawns, turbot, bream, sturgeon, salmonids, etc.), and the difficulties of development are on average no greater for systems producing species of high commercial value than for any other species.

Extensive aquaculture could also benefit from a better image than that of fishing and intensive aquaculture. As demonstrated by the actions of ecological movements against the fishing of culturally sensitive species, the inability to prevent overexploitation and to manage the conflicts within the fishing industry are starting to tarnish the excellent image this activity once enjoyed. The image of intensive aquaculture suffers from the damage it is accused of doing to the environment (deterioration of landscapes, milieus and aquatic populations). Its capacity to produce quality products is also called into question, an opinion that the recent mishaps in agriculture have done nothing to correct. The high consumption of fishmeal, fresh water (for the production of smolts in salmon culture) and energy in intensive aquaculture may also be detrimental to its image. By comparison, see ranching could appear to be a more environmentally-friendly activity, and one capable of producing a more natural type of food (provided that the quality of the environment is preserved at the same time). Another aspect that should not be ignored in countries where leisure activities are becoming increasingly important is that it may also contribute to the development and diversification of recreational activities.

The health risk and the difficulty of controlling the quality of the products have so far constituted a serious obstacle to the development of international trade in shellfish. The harmonisation of national quality control legislation being pursued by the European Commission (§ 5.3) should reduce this constraint.

There is thus reason to believe that extensive systems will enjoy strong demand and generally be looked more favourably than the other modes of production. But this conclusion does not mean that such systems will be able to live up to this expectation in practice.

5.3 – The role of the public sector

Research

The development and installation of extensive systems gives rise to complex questions that research, if it is efficient, may help to resolve. The public sector has a particular role to play in the production of knowledge about issues whose scale takes them out of the field of interest of private operators:

Our examination of the conditions required for take-off and the optimisation of extensive systems highlighted the variety of the disciplines potentially useful for the study of these questions:

It revealed above all that progress in extensive aquaculture depends on the capacity to provide overall responses to complex and coherent sets of questions which differ according to the nature and state of advance of the production systems considered. The lack of coverage and coherence of the research programmes may be considered to be the main cause of past failures. For a long time, targeted research was concerned above all with small-scale questions (such as artificial reproduction) and tended to pay less attention to larger questions (such as the regulation of the natural populations in the aquatic milieu in the biological sciences, or the process of technical intensification, the regulation of access to resources and the role of the ownership in the development and use of renewable marine resources in the human sciences).

Significant efficiency gains may thus be expected from adopting a multidisciplinary approach including the following elements:

Two other causes of inefficiency frequently cited in the literature concern the lack of rigour in the experimental protocols (explicit formulation of testable hypotheses) and the confusion between research and development (Peterman, 1991). These two shortcomings are not independent. While the association of development projects and experimental programmes makes it easier to obtain research funding, this type of funding often hampers the establishment of rigorous experimental protocols and leads to the abandonment of the investigations when the results do not confirm the initial hypotheses.

Research on extensive systems may contribute to the advancement of knowledge on questions of great scientific interest: regulation of marine populations, domestication and technical intensification of aquatic resources, the role of institutions in the exploitation and conservation of these resources. Because they permit full-scale experimentation on the ecology of marine populations, major extensive aquaculture programmes, like those implemented in France on scallops or in Norway on cod, are likely to be of interest to basic research. This interest may facilitate the mobilisation of theoretical and methodological competencies necessary for the study of new questions concerning the exploitation of the living resources of the sea.

Control of the quality of the environment and of aquacultural stocks and products

The scale of the controls necessary and concern for the protection of consumers’ health justify the intervention of the public sector in three other fields: conservation of environmental quality, preservation of the health of the stocks, and quality control of the products. These three fields are connected with one another. The fact that the state of health of the stocks and the wholesomeness of the products depend upon the quality of the environment explains why the European countries concerned themselves very early – right from the beginning of the century in some cases – with setting up monitoring systems for milieus, stocks and products of cultivation. In 1991, a European directive (91/492 of 15 July 1991) harmonised the legislation of the EU member states in this field. A system of four levels of wholesomeness was instituted (Table 1). It has three objectives: conservation of the cultivation milieu, prevention of epizootic diseases, and consumer protection.

Table 1 - New classification of oyster growing areas applied since 1 January 1996 in the European Union.

Areas

Upper limit

Exploitation

Natural beds

Cultures

Fit for consumption

300 faecal coliforms/100 g of flesh

authorised (direct consumption)

authorised (direct consumption)

Exploitable

6 000 faecal coliforms/100 g of flesh

authorised (relaying or purification)

authorised (relaying or purification)

Exploitable

60 000 faecal coliforms/ 100 g of flesh

+ heavy metals

+ pesticides

authorised (relaying - > 2 months - or purification)

prohibited (except in the case of derogation)

Not fit for human consumption

  

prohibited

prohibited

Being reactive, these measures do not address the causes of the degradation of the quality of the coastal milieu or inland seas, only the effects. The passage to preventive requires the adjustment of the institutions.

Adjustment of the institutions to new conditions

In the maritime field, technical intensification and the rationalisation of production are hampered by the regimes regulating access to the natural resources. Recent historical studies in the fields of economics and sociology stress role of institutions, and in particular of ownership regimes, in economic growth. For some commentators they are even considered to be fundamental: ‘ … innovation, economies of scale, education, capital accumulation, etc…, are not causes of growth, … Growth will simply not occur unless the existing economic organisation is efficient. Individuals must be lured by incentives to undertake the socially desirable activities. Some mechanisms must be devised to bring social and private rates of return into closer parity … A discrepancy between private and social benefits or costs means that some third party or parties, without their consent, will receive some of the benefits or incur some of the costs. Such a difference occurs whenever property rights are poorly defined, or are not enforced’ (North10 and Thomas, 1973). This theory is particularly relevant in the maritime world where, as compared with terrestrial regimes, the institutions governing access to natural resources still have difficulty, despite recent advances in the law of the sea, in adapting to the new situation of the scarcity of natural resources.

At both national and international level, collective initiatives to regulate access are bound to remain uncertain so long as they are not formalised. The problem is that collective decisions do not commit third parties. This is why, over the centuries, when it has been a matter of assuring regalian functions (army, justice, police and money) on which the regulation of access depends, public solutions have always ended up by taking precedence over individual or collective initiatives. To limit theft and freeloading, the application of a common regime has always turned out less costly in the end and public solutions have prevailed.

But the expectation of considerable social benefits does not mean that the institutions necessary for their concretisation emerge spontaneously. Institutional innovations differ in this respect from technical innovations. While the latter may cost a lot, their exploitation is often within the reach of private initiatives, and their benefits go to individuals who are prepared to take the risk. Institutional reforms, for their part, come up against the opposition of vested interests, the inertia of the bureaucracies, and people’s apprehensions about the social consequences of change. These constraints have a high immediate cost. But above all, the potential benefits fall to society as a whole, and not to the politicians or administrations who would be prepared to promote them. Under these circumstances advocates of reform are thin on the ground. While the solutions adopted by societies for their organisation may be rational, they do not necessarily seize the opportunities presented to them. The great geographical and sectoral disparities in economic development are indicative of the non deterministic nature of the evolution of societies. Because the adjustment of institutions is part of the political process and depends on public initiatives whose realisation is not a foregone conclusion, the public authorities should direct their efforts at the adjustment of the institutions to new conditions, rather than the support of production and the defence of professional interests.

6 - Conclusions

The analysis of extensive systems makes it possible to assess the prospects and identify and rank the conditions necessary for the development and rationalisation of this mode of production.

The most plausible hypothesis we can put forward on the basis of the theories on the regulation of the marine populations and the level of production of mature systems is that, from the ecological standpoint, the potential of extensive aquaculture could be comparable with or even better than that of fishing. While the extensive cultivation of new species gives rise to complex questions, on the whole these problems can be solved by marine ecology.

The technical problems do not constitute an insuperable obstacle either. Several very productive systems are based on simple techniques. A good many R&D programmes which have not resulted in commercial production have been successful from the technical standpoint. The list of species whose reproduction is mastered (Appendix 2) is considerably longer than that of the species which are commercially cultivated, and is getting steadily longer with the development of intensive aquaculture.

The stumbling block is no longer economic. Like shellfish culture, several extensive systems are perfectly profitable. The method is transposable to other species of great commercial value. The deficit of sea products and the high prices which are likely to persist in Europe for species which are not being produced by intensive cultivation are favourable for the diversification of extensive aquaculture. From this standpoint extensive aquaculture probably offers more flexibility than intensive systems.

However, the actual progress of this mode of production is not in line with these conclusions. The most developed systems are old and rustic. Recent research has not led to any significant production in Europe. The only marine cultivation of vagile species which has reached a certain level of development - salmon ranching - also dates back several decades. For Europe as a whole, its production is probably less by an order of magnitude than that of shellfish culture.

The main obstacles seem to be legal and institutional. A comparison of the main cultivation systems reveals the existence of strong correlations between the level of development of the production process - and hence the process of domestication -, the economic and social structure of the operation, the development of individual ownership and the ease of appropriation of the stock. Thus shellfish culture is characterised by the conjunction of private farmers, owners of a stock whose appropriation is facilitated by its sedentariness. On the other hand, where the problems arise is in the adjustment of the shellfish farming stocks to the biotic capacity of the basins and the allocation of the natural capacities of the ecosystems between shellfish farming and competing uses. These problems have not received the attention they deserve in view of what is at stake. The reasons for this are to be found in the fluidity of the ecosystems which complicates their appropriation, and the fuzzy nature of their legal status which prevents the obvious decisions from being taken. The restocking of salmon, for its part, is aimed at the conservation of the wild fauna and the support of stocks exploited in fisheries where access is poorly regulated. The fuzziness of the legal status of the stocks, predation by outside fishermen, and the poor correspondence between the public cost of rearing the fry and the private gains of the operators block the financing of restocking. By contrast, the better results obtained by Japan in the development of the extensive aquaculture are connected with the collective ownership regime for natural resources that this country has adopted.

When, in the 60s and 70s, the fall off in halieutic production gave rise to a new enthusiasm for aquaculture, the comparison with agriculture was often invoked to justify an intensification of the R&D effort for the benefit of marine aquaculture. While the analysis of the systems of production does indeed confirm the similarity of the process of intensification in the marine and land systems, it also reveals differences which invalidate the analogy with the Neolithic Revolution.

The first difference is that the process of artificialisation started very much later in the sea than on land, because until after the Second World War, the demand for sea products could be satisfied by the extension of fishing operations. Up to that time, societies had thus been able to do without domestication - apart from shellfish culture whose development was simple. Today, exploitation of the living resources of the ocean - whether it is a matter of the rationalisation of mature systems like fishing or shellfish culture or the domestication of new species -, the conservation of the environment and the allocation of its limited capacities between constantly growing and diversifying uses require the adoption of institutions which make it possible to effectively regulate access.

The second difference is that the natural resources of the sea are on a much greater scale than terrestrial resources. The fluidity of the milieu and the mobility of the stocks complicate domestication and the development of appropriate institutions. The solution adopted several centuries ago in agriculture, i.e. the dividing up of the land, is no more transposable to aquaculture - with the exception of the ownership of sedentary stocks - than to fishing. But there are other ways of achieving the same ends.

The third difference is that recent studies on the origins of agriculture and the expansion of the first producing societies show the limits of explanations of the Neolithic Revolution based on purely technical (technical innovation) or economic (response to ecological, biological or demographic pressures) considerations (Cauvin, 1994; Mazoyer and Roudart, op. cit.). The seniority of the development of institutions governing terrestrial activities (in relation to the earlier development of agriculture, relayed by that of trade and industry) no doubt explains why the first public policies for the development of marine aquaculture were able to consider as suitable for the sea institutions which had served as the foundation for the development of the terrestrial activities, but which did not exist at sea.

At the international level, the extension of national jurisdictions constitutes a historic stage in the exploitation of the oceans. It gives maritime states the possibility of introducing in their territorial waters the systems of exclusivity necessary for the promotion of domestication and the rationalisation of their uses. But adjustment to the new conditions is still in the very early stages. With the regimes in force, the private and social costs and benefits coincide badly: would-be fish farmers cannot be given the guarantees which would incite them to invest in new systems, whereas in the mature systems producers have an interest in increasing their stocks beyond the minimum necessary for satisfactorily exploiting the trophic capacity of the milieu. The difficulties experienced by public authorities in performing their function as stewards of the natural heritage, and the inclination of the administrations to prefer established uses to the detriment of more promising new productions are explained by the fuzziness of the regimes of exclusivity and the ineffectiveness of administrative regulation as a method of allocating rights of use.

When it comes to adjusting the uses to the capacity of the natural resources, the effectiveness of the regulation structures depends on the coincidence between their area of competence and the spatial structure of the natural resources. Given the obvious diversity of the scales of the unitary resources and the tracing of political frontiers, the existence of such a correspondence is a matter of chance. In reality, two units dominate the structure of the resources - the animal or vegetable population, and the ecosystem; these units are independent of the uses and their scales make it possible to envisage a considerable decentralisation of their development - at the local level for coastal resources, and regional (provincial) for the resources of the continental shelf.

The creation of independent public agencies, controlled by authorities made up of representatives of the competent administrations and user groups to be responsible for allocating rights of use, would be a solution to these problems. This arrangement is commonly used in the exploitation and conservation of terrestrial resources such as forests or water resources. The integration of development would be furthered if the competences of these agencies covered natural resources independently of their uses. As stewards of the natural heritage, they could, through extracting the natural scarcity rent of the resources, effectively attack the root cause of the overexploitation and use this revenue to cover the expenditures inherent in their functions (monitoring and evaluation of resources and their uses, allocation of rights, control and surveillance), and finance programmes for the exploitation of natural resources (restocking and overpopulation, eradication of non-indigenous species).

It is unlikely however that the positive potential for extensive aquaculture will suffice to trigger such reforms. But examination of the lost opportunities in extensive aquaculture may help further raise an awareness already aroused by the obvious inadequacy of the present control of fishing or the conservation of the marine environment.

Thinking on institutional reforms is already well advanced. Several countries have undertaken to reform their fisheries regulation. In view of the similarity and complementarity of the problems, the analyses would gain if the regulation of the aquacultural systems and the conservation of the environment were part of the same programmes. The basic theoretical knowledge and the necessary field observations are available. A comparative study of the institutions covering all of the uses of the natural resources could lead to an analytical grid which would make it possible to compare the merits of the different methods of regulation that may be envisaged as a function of predefined criteria, and to understand the conditions of evolution of the institutions in different contexts. The restitution of this knowledge would fuel the debate with the parties concerned (local authorities, administrations and user groups).

The period of adjustment is likely to be long however. This time could be put to good use for better understanding and discussing the problems of the development and organisation of extensive aquaculture. The implementation of carefully selected programmes, covering all aspects of the problem, could help here. Some could be concerned with the diversification of shellfish culture - in order to take advantage of the ease of appropriation of the stock -, others with the collective exploitation of vagile species - in order to evaluate the potential of this system. In this latter case it would be preferable to choose species whose area of dispersion is coastal and restricted. In both cases, species of high commercial value or likely to give rise to activities for which there is a solvable demand (sport fishing) should be given priority. The scallop would be a good candidate for the first programme, and the turbot would no doubt be a good choice for the second.

Feasibility studies should go beyond the technical and economic aspects, and analyse the coherence between the production objective, the area of distribution of the stock, the ownership regime of the natural resource, the economic and social structure of the operation, and the mechanism for allocating of the rights of use. These programmes would be aimed at demonstrating the ecological and technical feasibility and the economic interest of extensive aquaculture, as well as evaluating the economic consequences of the inadequacies of the regulation mechanisms now in force. For these reasons, it is important to have good communication between the parties concerned - including the general public. As earlier programmes have shown, integrated studies of this type may advance knowledge on questions of great scientific and economic interest, as well as the regulation mechanisms for marine populations, the organisation of fishing, the domestication of living resources, the fight against the colonisation of exotic species, and the conservation of the environment. Though encouraging debate on issues such as the role of ownership in the process of technical intensification and the conservation of the environment, they could contribute to the advancement of thinking on sensitive issues such as economic development processes. The success of such programmes will depend on their coherence, the rigour of their conception, and the mobilisation and coordination of the disciplines necessary for their execution. For this, it appears to be essential to use systems analysis methods and a multidisciplinary approach.

References

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Appendix 1

Main shellfish farming production in Europe (in tonnes, 1966; source: FAO, 1998)

Country

Abalone1

Northern periwinkle2

Oysters3

Mussels4

Scallops, small scallops5

Cockles, clams6

Total

Albania

      

250

    

250

Germany

    

75

38 028

  

110

38 213

Bulgaria

      

42

    

42

Croatia

    

44

214

    

258

Spain

    

3 720

188 462

207

5 672

198 061

France

  

1 137

152 129

61 962

150

2 800

218 178

Greece

    

10

10 194

  

21

10 225

Ireland

    

4 355

14 500

40

125

19 020

Italy

      

100 000

  

40 300

140 300

Norway

      

15

    

15

Netherlands

    

1 100

94 496

    

95 596

Portugal

    

662

136

  

18 515

19 313

United Kingdom

6

  

1 336

8 847

76

99

10 364

Russia

      

610

    

610

Slovenia

      

50

    

50

Sweden

      

1 821

    

1 821

Ukraine

      

250

    

250

Total

6

1 137

163 431

519 877

473

67 642

752 566

1 - Haliotis tuberculata; 2 - Littorina spp; 3 - Ostrea edulis, Crassostrea gigas, C. angulata; 4 - Mytilus edulis, M. galloprovincialis; 5 - Pecten maximus, Chlamys opercularis; 6 - Cardium edule, Ruditappes decussatus, R. philippinarum, Tapes pullustra, T. spp, Veneridæ.

Appendix 2

List of European marine species1 whose the reproduction is more or less well mastered
(P. Arzel, J-C. Dao, HAS. Dosdat and J-L. Gaignon, IFREMER, personal communication).

 

Collection of wild juveniles

Collection of spat in natural milieu

Artificial reproduction (hatchery)

     

Fairly well mastered

Well mastered

* algae

      

Laminaria (L. digitata)

Lichen (Chondrus crispus)

Gelidium (?)

* echinoderms

    

Sea urchin (Echinus esculentus, Paracentrotus lividus)

  

* shellfish

Mussels (Mytilus edulis, M. galloprovincialis)

Cockles (Cardium edule)

Oysters (Crassostrea virginica, Ostrea edulis)

Abalone (Haliotis tuberculata)

Oysters

Mussels

Clams (Tapes decussatus) Scallops (Pecten maximus)

* cephalopods

    

squid (?)

Octopus (Eledone moscata, ?)

  

* crustaceans

    

Prawns (Palæmon serratus)

Green crab(Carcinus mænas)

Lobster (Homarus vulgaris)

  

* fish

Eel (Anguilla anguilla)

Tuna (Thunnus thynnus)

  

Sturgeon (Acipenser sturio, HAS. ?)

Halibut (Hippoglossus hippoglossus)

Plaice (Pleuronectes platessa)

Dolphin fish (Coryphæna hippurus)

Sparids (Sparus aurata, S. pagrus, Dentex dentex, Diplodus puntazzo, D. sargus)

Croakers (Argyrosomus regius , Sciæna umbra, S. cirrosa)

Red grouper (Epinephelus ?)

Pollack (Pollachius pollachius)

Atlantic wolffish (Anarhichas lupus)

Herring (Clupea harengus)

Mullet (?)

Trout (Oncorhynchus mykiss, Salmo trutta)

Atlantic salmon (Salmo salar)

Bar (Dicentrarchus labrax)

Cod (Gadus morrhua)

Sole (Solea solea)

Turbot (Psetta maxima)

* reptiles

Green turtle (?)

      

1 - In addition, exotic species have been, or are, commonly cultivated in European waters: algae (L. Japanica, Undaria Japanica, Macrocystis sp.), Philippines clam (Ruditappes philippinarum), prawns (Penæus kerathurus, P. ?), Sparids (Pagrus major).

Reporting committee: Committee on Agriculture and Rural Development

Budgetary implications for the Assembly: none

Reference to committee: Doc. 7674 and Reference No. 2130 of 6 November 1996

Draft resolution unanimously adopted by the committee on 24 June 1999

Members of the committee: Mr Behrendt (Chairman), MM. Seiler (Vice-Chairman), Hadjidemetriou (Vice-Chairman), Hornung (Vice-Chairman), MM. Agius, Aliko, Anton, Aylward, Bojars, de Carolis (Alternate: Robol), Carvalho, Čiupaila, Eltz, Etherington, Mrs Gatterer, MM. Ghesquière, Gremetz, Haraldsson, Janowski, Jung (Alternate: Goulet), Kharitonov, Kitov, Kofod-Svendsen, Korkeaoja, Lazarenko (Alternate: Kosakivsky), van der Linden, Mrs Loule, Mrs Mikaelsson, MM. Myrvoll, Pisanu, Prokes, Prusak, Regenwetter, Rupar, Sainz Garcia, Simon, Shugarov, Skopal, Steolea, Taylor, John D., Yürür.

N.B. The names of those members present at the meeting are printed in italics.

Secretary to the committee: Mr Sixto.

1 - ‘For the purposes of this enquiry aquaculture has been defined as: “Aquaculture is the farming of aquatic organisms, including fish, molluscs, crustaceans and aquatic plants. Farming implies some form of intervention in the rearing process to enhance production, such as regular stocking, feeding, protection from predators, etc. Farming also implies individual or corporate ownership of the stock being cultivated. For statistical purposes, aquatic organisms which are harvested by an individual or corporate body which has owned them throughout their rearing period contribute to aquaculture, while aquatic organisms which are exploitable by the public as a common property resource, with or without appropriate licences, are the harvest of fisheries’. (FAO, 1998a).

2 Total production in the NE Atlantic has fallen by 11% over the past 25 years, in the Mediterranean by 10% during the present decade (FAO, 1997). All the stocks of average and high commercial value in European seas are economically or biologically overexploited (CE, 1990 and 1998).

3 - In the present state of development of the techniques, such systems are not commercially viable outside hatcheries.

4 - See definitions fig. 4, p. 20.

5 - Recruitment means both the process which leads to the incorporation of the year’s fish to the population to which they belong, and the result of this process – i.e. the number which come each year to compensate the population losses through natural mortality and fishing.

6 - Which, like the salmon, frequent alternately the marine environment where they fatten and inland waters where they reproduce.

7 - Algoculture can be analysed in similar terms, with the difference that the system does not benefit in Europe from the eating habits that exist in the Far East (at least not on the same scale), and that the price of the products is on average relatively low.

8 - The PUSH (Development and Encouragement of Sea Ranching) Programme was launched in 1989 by the Norwegian Government for a period of 8 years (1990-97). Its aim was to determine the conditions necessary for the profitable sea ranching of four main species: Atlantic salmon, arctic char, cod and lobster.

9 - Such a project is also being implemented in the Arcachon basin, France (Muir, 1998).

10 - Nobel Prize for Economics, 1993.