Sc. Let us discuss some of the arguments presented by supporters and critics. Kobayashi, T., 1980 - ‘Salmon propagation in Japan’. Some of these wastes can enter water systems and can contaminate drinking water in the homes. ; - zootechnics: artificial reproduction, pathology and prophylaxis, genetics, etc. Despite these controls, exotic species are regularly introduced on the occasion of imports of spat and illegal immersion of shellfish before their commercialisation. 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. Also, this also becomes the source of food establishments and restaurants that serve seafood like prawns, clams and salmon, among others. We give you the best daily information on news, technology, lifestyle, career, health tips, agriculture, business and entertainment. 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. 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). 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. Jr and R.G. Being a matter of allocating a factor of production in a competitive activity, experience shows that these methods, whether they are used separately or jointly, are less efficient for controlling overexploitation than economic mechanisms - taxation or market mechanisms. 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). 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). The technical problems do not constitute an insuperable obstacle either. 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 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.

On the other hand, in Europe, research into lobster (France, United Kingdom, Norway) and cod (Norwegian PUSH8 programme) reached negative conclusions. Some of them include: Many dreams and ambitions go to the grave, sadly because they were not funded. 83’. For these reasons, it is important to have good communication between the parties concerned - including the general public. Its aim was to determine the conditions necessary for the profitable sea ranching of four main species: Atlantic salmon, arctic char, cod and lobster. It was justified when the prime responsibility of the administrations was to defend the interests of their national fleets, free to operate in the world ocean, but this is no longer the case since the adjustment of the uses to the potentials of the natural resources has become the main consideration, and now that the extension of national jurisdictions has given national authorities the power to exercise their responsibilities on the scale of the unitary resources; - modernisation of the mechanisms for allocating rights of use: the origin of the dynamic of overexploitation being economic, economic mechanisms are generally more efficient for rationalising the commercial uses and, as a result, conserving the resources. 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. 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. 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). While technical intensification reduces the role of the natural resource, it does not eliminate the dependence of production vis-à-vis the environment. 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. Another drawback of the practice of aquaculture is the need for wild fish to be fed to culture fish like salmon. All these fall into one category - fish farming and we will discuss them as that. Extensive aquaculture is characterised by a production function in which human intervention is concentrated on the reproduction of the stock (fig.

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. Focusing on technical innovation, it under-estimates the institutional reforms on which its success depends. The scallop would be a good candidate for the first programme, and the turbot would no doubt be a good choice for the second. 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.

Certain countries (Iceland, Chile and, in the USA, the states of Alaska, Oregon, Washington, and California on an experimental basis, etc.) 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). 10; Rome, Italie; 197 p. FAO, 1998b - ‘ Statistiques des pêches; Produits, 1996, vol. Lastly, the private ownership of the stock is virtually the rule in intensive fish farms. On the other hand the poor correspondence, frequent in extensive systems, between social and private costs and benefits is a major handicap. 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. cit. On the world scale it is estimated that some 70 % pollution ends up in the sea.