Aquaculture in the Republic of Belarus is characterized by four main farming systems: fish pond farming, warmwater and industrial fish farming (rearing fish in cages in warmwaters of power plants in closed-loop water supply systems) and fish rearing in natural and artificial water bodies (culture-based fisheries). The main cultured species in Belarus is common carp (Cyprinus carpio), which currently accounts for 79.7 percent of total national aquaculture production. Fish pond farming is the main method of production.
There are currently 22 fish pond farms (under various forms of ownership), three fish farms havesting and processing lake and river fish, five fish hatcheries rearing seed for stocking lakes and reservoirs, two warmwater cage systems (belonging to fish farms) and one cold water trout farm (Konchits, 2005). Different management and ownership systems are in operation.
The total pond surface of the country is 24 530 ha, of which 20 800 ha belong to the state owned fish farms and 3 730 ha to agricultural enterprises of communal-municipal ownership. The existing pond capacities allow an annual production of up to 19 900 tonnes of marketable fish, of which the enterprises of the Ministry of Agriculture and Food yield up to 16 600 tonnes (Konchits, 2001 and 2002).
Over recent years, privately owned enterprises (farmers, private entrepreneurs and firms) have begun aquaculture production activities. The majority (54 farms in six provinces) rear fish in leased natural and artificial water bodies according to culture-based fisheries, i.e. fattening of fish stocked in polyculture on a natural food base and their subsequent harvesting using commercial fishing gear. Two enterprises have opted to specialize in trout rearing from imported fry, and two others in sturgeon rearing using industrial methods.
The main freshwater fish producer of the country is the Department of Water Management and Melioration of the Ministry of Agriculture and Food of the Republic of Belarus, bringing together 19 fish pond farms and one that rears stocking material and harvests fish in natural water bodies. They are responsible for about 88 percent of the annual fish production of the country. Total aquaculture production reported to FAO in 2004 was 4 150 tonnes.
The main cultured species in Belarus is common carp (Cyprinus carpio), which currently accounts for 79.7 percent of total national aquaculture production. Other cultured species are goldfish (Carassius auratus auratus) 10 percent, Chinese carps: grass carp (Ctenopharyngodon idellus), silver carp (Hypophthalmichthys molitrix) and bighead carp (Hypophthalmichthys nobilis) with an overall production of about 8 percent, and Northern pike (Esox lucius) 1.8 percent. Of other species, smaller quantities of tench (Tinca tinca), wels catfish (Silurus glanis), rainbow trout (Oncorhynchus mykiss) and sterlet (Acipenser ruthenus) are cultured, but the production volumes of these species do not exceed 0.5 percent.
All fish species are reared using classic selection methods, without genotype modification. In fish culture practice, mainly hybridisation (interbreed and interline crosses of common carp) is used. Technologies for obtaining intergenus hybrids (bighead carp X silver carp, common carp X goldfish) are developed and small quantities of these are used. Currently genetically modified species are not used in the country.
The ancestor of common carp cultured in ponds of Belarus was the Galician common carp, the blood of which still flows in pure lines of Belarus carps (Zhukov, 1994). In later times, common carp was crossed with Amur wild carp to increase its resistance to unfavourable conditions and this gave rise to elongated scaly forms. Due to the efforts of selection scientists and practical fish farmers of Belarus, the "Lakhvinskiy scaly" common carp breed reared by half of the country's farms has now been selected and approved, and the following breeds have to enter the approval process: "Izobelinskiy common carp" (without wild carp blood) and "Tremlyanskiy common carp," represented by scaly and mirror lineages.
Chinese carps were introduced to Belarus at the beginning of the 1960s from fish farms of the Russian Federation and the Central Asian republics. Most of the production consists of grass and bighead carps, while silver carp, preferring warmer waters, does not exceed 10 percent of production volumes. Of indigenous species, the highest production volumes are reached by Northern pike. Breeders of this species are collected in natural waters, while fish obtained in pond conditions are used in further reproduction.
Wels catfish, zander and tench offer a certain potential. Their broodstocks are also formed using fish caught in natural waters. Selection work with the offspring is going on with a view to their more widespread use in fish pond farming.
Exercise 1
Find in the text English equivalents of the following words and word combinations:
промышленное рыбоводство; замкнутая система водоснабжения; искусственно выращенные виды; рыбоводный завод; рыболовное орудие; природный водоем; специализироваться в разведении форели; обыкновенный карп; серебряный карась; белый амур; толстолобик; обыкновенная щука; обыкновенный сом; радужная форель; судак; линь.
Exercise 2
Complete the sentences:
1. Aquaculture in the Republic of Belarus is characterized by …
2. The main cultured species in Belarus is …
3. The total pond surface of the country is …
4. The main freshwater fish producer of the country is …
5. All fish species are reared using …
Exercise 3
Answer the questions:
1. What are the four main farming systems of aquaculture in the Republic of Belarus?
2. Are there many fish pond farms and fish hatcheries in our country?
3. Where does the majority of privately owned enterprises rear fish?
4. What are the main cultured species in Belarus?
5. What methods and technologies are used in fish rearing?
Discussion
Do yon agree or not? Comment on the following statements.
1. The best fish swim near the bottom.
Дата: 2019-02-24, просмотров: 272.