HUNGARY
The judicious use of natural resources: Aquaculture in Hungary contributes to biodiversity, flood management and environmental sustainability
Pond farming should be better acknowledged Modern pond aquaculture production originates in the Danube basin, and in the European Union about 60% of it is still connected with this catchment area. The biogeographic features of pond aquaculture production define the spectrum of produced species and applied technologies.
Hosting carps and predatory species in polyculture The production cycle typically takes three years. In the first year the product is 60-150 g fingerlings, while in the second year it is 500800 g juveniles. Market size carp of 2-3 kg are produced in the third year. The area requirements of the age classes are different, thus in those farms which produce all three age classes yearly, 5% of their net water surface area is used for fingerling rearing, 20% is used for juvenile rearing and 75% is used for market size fish. Fish pond production is typically managed in polyculture, where common carp is produced in combination with other fish species of the same age class. Common carp is the most widely produced species
accounting for 80% of the total pond based fish production in 2018 (AKI 2019). Besides common carp typical pond fish species are silver carp, grass carp, and predatory fish species including catfish, pikeperch and pike. Fish pond production is a semiintensive farming technology. Organic manure is used to augment the natural feed present in the pond. In addition, the natural feed — zooplankton mostly — can be complemented with the use of cereals and plant based feeds of high protein content (e.g. oil-extracted sun flower seeds, lupine, pea). The ratio of the yields received from naturally available feed and from feeding are typically similar, 50-50%, however this varies significantly between farms, based on the way they are managed. Over the last 10 years, pond production has become more extensive in Hungary as farmers seek to minimise costs and increase profitability.
Ponds and natural wetlands have many similarities Pond fish farming, besides producing common carp, creates a fish pond ecosystem that is closely related to natural wetland habitats. Although this is
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ishpond production dominates Hungarian aquaculture with an output of 81% of the total in 2018, according to the Research Institute of Agricultural Economics (AKI). Fishponds are defined as artificial structures which can be fully filled and drained through their monks. The average fish pond is 30-40 ha in Hungary and there are mainly two types: barrage ponds in hilly areas and paddy ponds mainly on the plains.
Fish grow-out ponds are 30-40 ha on average, but can also be considerably larger.
an artificial system, the nature of nutrient cycling is identical to that of natural wetlands. The fish pond ecosystem is similar to the natural aquatic ecological systems in complexity. The larger homogeneous habitat patches (e.g. open water, dry pond bottom, reeds) allow specific taxa to be more diverse than in natural habitats, however, on the whole the biodiversity of fishponds is lower than that of natural wetlands. An attribute of the fish pond ecosystem is the dominance of planktonic organisms which feed on the dissolved nutrients in the water. Unless the proper amount of common carp juveniles are added to the system the pond will be converted into a shallow aquatic habitat with
homogeneous marshy vegetation (reed communities, willow-shrub vegetation) in only three-four years. The increased nutrient input enhances the population sizes at all levels of the food web, so that fish ponds maintain notably higher quantity of organisms compared to natural ecosystems. With a shift to a more extensive technology, the nutrient input decreases or ceases completely, the nutrient sources in the pond diminish, and there is a decrease in the population sizes of all the organisms in the pond. The appropriate strategies for farming fish are vital for production levels and for the health of the pond itself. Another unique attribute of fish ponds is the seasonality of water coverage. Due to the technological processes, the different
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