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La productivité d'eau dépend des paramètres tel que température, oxygène dissous, pH et minéraux essentiels. Quelques-uns peuvent être mesurés et peuvent contribuer pour décider des interventions telles qu'oxygénation, liming, fécondation ou provision de l'alimentation. Ces méthodes sont primitives cependant et devraient être améliorées., Water productivity depends on parameters such as temperature, dissolved oxygen, pH and essential minerals. Some of them can be measured and may contribute to decide some interventions such as oxygenation, liming, fertilization or feed supply. These methods are however primitive and should be improved.

National audience

The concept of fish polyculture has been developed and applied widely in China. The principle is based on the mixing in the same biotope of several non competing animal species and utilization of different ecological niches. The intention is to obtain a better valorization of the renewable resources of the water body. Polyculture is a situation located between the natural ecosystem in which the energy flux is distributed over the many components of the system and monoculture where the flux is concentrated on only one species. In mono- as in polyculture the dietary biomass remains smaller than that produced by the ecosystem without any human intervention. However, the priviliged direction of the flux towads some species easier to harvest allows to collect a larger amount of consumable living matters. Polyculture has led to a marked production increase (generally the double of the production obtained in monoculture without any supply of fertilizers or feed supplements). The main difficulty arises from the choice of the different species and their respective stocking rates in the pond. The most currently mixed species belonging to temperate zones: the common carp and the Chinese carps. In Europe, polyculture is widely practised in USSR and in Rumania and is starting in Hungary, Yugoslavia and Poland. Other countries such as Israel have extended the range of associated species by using Tilapia and even grey mullets together with common carp and Chinese carps and sometimes freshwater shrimps or bivalves in coastal zones.

Dans les pays industrialisés, l'écosystème aquatique n'est pas amené en charge par en a structuré le corps professionnel et plus souvent ne dépend pas de toute administration spécifique. En Asie l'écosystème aquatique a été intégré dans l'écosystème agricole: il obtient une grande production de protéines, basé sur la production naturelle de l'environnement, autorise le traitement des déchets, assure la protection de l'écosystème agricole. Le concept de cette intégration symbiotique de l'écosystème aquatique dans l'activites agricole général représente un premier pas dans le développement des régions d'eau différentes. Dans le futur, un deuxième pas consistera dans l'organisation d'une agriculture vraie d'eaux, avec une évaluation de la chaîne alimentaire, contrôle de la biomasse, association spatiale et temporelle d'espèces, contrôle de cycle de la vie de l'espèce, hygiène, etc. Cette deuxième phase suppose un effort de la recherche fort que la plupart des pays ne paraissent pas prêts à faire à présent. C'est logique de penser cependant que l'environnement aquatique, productif de ressources renouvelables et responsable recycler volonté des gaspillages quelque jour soit complètement développé dans les pays industrialisés., In industrialized countries, the aquatic ecosystem is not taken in charge by any structured professional body and most often does not depend on any specific administration. In Asia the aquatic ecosystem has been integrated into the agricultural ecosystem : it secures a large production of proteins, based on the natural production of the environment, allows waste treatment, ensures the protection of the agricultural ecosystem. The concept of this symbiotic integration of the aquatic ecosystem into the general agricultural activites represents a first step in the development of the different water areas. In the future, a second step will consist in the organization of a true agriculture of waters, with an estimate of the alimentary chain, biomass control, spatial and temporal association of species, control of species life cycle, hygiene, etc. This second phase supposes a strong research effort which most countries do not seem ready to make at the present time. It is however logical to think that the aquatic environment, productive of renewable resources and liable to reprocess wastes will some day be fully developed in industrialized countries.

La pisciculture en étang

L'étang et l'agriculture des eaux