Fish farming facilities for cultivation in agricultural reservoirs with intense hydrochemical regime

Abstract

Agricultural reservoirs built on acidic, swampy soils, peat processing, as a rule, have a tense hydrochemical regime. Overseas phenomena are also a natural consequence of the intensification of pond fish farming. In the hottest time of the year (most often in July, the first half of August), the massive development of phyto-, zooplankton, benthos and, above all, microorganisms (bacteria), compaction of fish planting for cultivation, intensive feeding with artificial feeds, lead to the accumulation of organic matter and a sharp decrease in oxygen content in water. One of the ways to develop such lands is to expand the number of breeding facilities with increased resilience. Widespread, the most hardy, having high nutritional qualities of fish — golden and silver crucian carp, as well as their hybrids have considerable commercial value in reservoirs of various origins and conditions, especially unfavorable hydrochemical regime. A promising object is the snakehead. This is a predatory freshwater Far Eastern fish, which is characterized by rapid growth and has high-quality meat. It breathes both at the expense of oxygen dissolved in water, and at the expense of atmospheric air, for breathing which it has a gill organ. The snakehead cannot exist only due to water respiration by gills. It feeds at a young age mainly on crustaceans and insects. As they grow, more and more switch to fish food, and large specimens feed almost exclusively on fish and frogs. In reservoirs with a tense hydrochemical regime, due to its unpretentiousness and undemanding to oxygen, tench can be grown. Tench is a promising object for breeding and stocking reservoirs. It is unpretentious, undemanding to water quality, can live in reservoirs with a very low oxygen content (up to 0.3 ml/l), a heavily silted bottom and acidic water, tolerating a decrease in pH to 5.