Rules for fish culture of organic food in large and medium-sized reservoirs

Code for organic food fish culture in large and medium-sized reservoirs

1 Scope of application

"Organic food fish culture regulations for large and medium-sized reservoirs" stipulates the selection of production areas, culture and fishing technology requirements for organic food fish culture in large and medium-sized reservoirs.

2 Standard reference files

The Regulations for Organic Food Fish Culture in Large and Medium-sized Reservoir is formulated with reference to GB/T19630 Organic Food, GB11607-89 Fishery Water Quality Standard, GB18 406.7 Fishery Water Sediment and other documents.

3 Definition of organic food

Organic food from large and medium-sized reservoirs refers to all agricultural and sideline products that come from organic farming systems, are farmed and processed according to organic certification standards, and are certified by qualified independent certification bodies.

4 Selection of breeding sites

The water quality of fishing waters conforms to the provisions of GB11607 -89, and the bottom quality of fishing waters conforms to the provisions of GB18 406.7. And no industrial waste and domestic garbage, no large plant debris and animal carcasses, no color, odor, natural structure.

5 Management of farming

5.1 Selected species

(1) Principles of selection. The origin is clear, the fish body surface is smooth, the mucus is rich, the body color is pure and consistent, there is no variegated color, the fin, the scale is complete, there is no injury, the swimming is fast, the top water is active and powerful, there is no deformity and no damage, the specifications of the same batch of fish species are neat, the individual difference is very small, and the data of the whole length, body length, head length, body height and body weight of various specifications meet the indexes stipulated by the state.

(2) Select conventional species. Transgenic fish species propagated by techniques such as triploid, parthenogenesis and genetic engineering are prohibited.

(3) Species. Applicable species are grass crab, red tail, gourd seed, silver carp, seasonal flowers, crucian carp, old head fish, carp, catfish, yellow catfish, hemp mouth, green root, green forest.

5.2 stocking of fish

The investment of organic food fish culture in large and medium-sized reservoirs is small, no bait, no fertilizer and no medicine are used, and the fish mainly rely on eating aquatic organisms. Reservoir fish culture should consider the type and quantity of bait in the water, so that the number and type of stocking fish species are adapted to it.

1) Fish farming. There are many plankton in large and medium-sized reservoirs, and filter-feeding fish have abundant natural food. Silver carp grows fastest, has large size and wide seed source, so it is the main breeding object.

(2) Quality of stocking specifications. Fish specifications to be large, physical fitness to be robust, this is the basis for high yield. Silver carp 16~18 cm. The quality is in accordance with the principles of species selection.

(3) stocking density. stocking density: 675 individuals/hm2·year. The stocking density is adjusted according to the growth rate and annual yield of various fish.

(4) Time and place of stocking. On October 5, stocking was carried out when the water temperature was 6~10 ℃. The drop sites shall be selected at the upper reaches of the reservoir area where the wind is sunny and the shore where the natural bait is rich, and multi-point drop shall be carried out.

(5) stocking operation. Disinfection and disease prevention are carried out on the fingerlings before storage, and the fingerlings are soaked in 25 - 40g/L salt for 5 - 10min, and the difference between the temperature of the salt water and the temperature of the reservoir water should be less than 3 DEG C so as to benefit the health of the fish body. After disinfection, the fish species are slowly placed into the reservoir. After the fish are stored, the stocking personnel stand at the edge of the reservoir or on the boat and gently tap the reservoir water with the paddle to urge the fish to swim to the large water area.

(6) Attentions. Breeding should be carried out in sunny and warm days. Fish should be dumped slowly when entering the water, allowing them to swim freely into the water, and equipped with oxygenators.

5.3 Daily farming management procedures

(1) Strengthen fishery administration. The core work of fishery administration is to properly handle the interests between the administrative organs of the reservoir area and the masses in the reservoir area. Fishery administration agencies in the reservoir area should strengthen ties with village organizations in the reservoir area, rely on these units to educate workers and villagers to abide by laws and regulations, and regularly send full-time personnel to patrol, stop stealing fish, electric fish, poisonous fish and fried fish in the reservoir, so as to ensure the steady development of fishery culture in the reservoir.

(2) Strengthen anti-escape management. Perfect escape prevention facilities, check fish blocking facilities frequently, and repair damage in time. Especially in flood season, it is necessary to strengthen the management of fish blocking facilities to minimize fish escape.

(3) Effective prevention of fish diseases. Large and medium-sized reservoirs, as long as the strict selection and use of high-quality, large-size fish species, carefully do a good job of disinfection before entering the reservoir, fish disease rarely occurs, do not use any chemicals to prevent fish disease.

(4) Regular inspection of reservoirs. Patrol the reservoir every morning and evening, observe the dynamics of the reservoir, strictly control the water quality, observe whether the fish have signs, whether there are solitary swimming or rapid swimming, disturbance and other phenomena, when the fish live normally, the water surface is calm, generally difficult to see, if abnormal activities are found, timely take measures.

(5) Do a good job of reservoir cleaning and sanitation. Contaminants in the reservoir shall be removed at any time to maintain a good reservoir environment. If death is found, it shall be removed in time and shall not be thrown away in order to avoid the spread of pathogens.

(6) Keep a good breeding journal. The culture log includes: stocking, fishing, water quality management, income and expenditure.

6 Control procedures for inputs

Fish cultured in Xingxing Reservoir grow naturally without any input (no bait, no fertilizer and no medicine). Fish mainly feed on aquatic organisms.

7 Fishing rules for adult fish

7.1 Common fishing gear

(1) Gill nets. Gill net is a long belt net made up of several rectangular net pieces. Reservoir fishing, with 3 layers of gill nets, namely 2 layers of large mesh nets sandwiched between a layer of small mesh nets composed. The net length is 50 m, and the height can be determined according to the depth and shallowness of each part of the reservoir. Usually 10 m, 15 m or 30 m. The gill net is vertically laid on the migration channel of fish, and the fish penetrates the net when migrating or fleeing in shock, or is entangled in the net and captured.

(2) Block. To intercept fish and close waters. It is a long belt mesh, each 50 m long, the total length of the reservoir is twice the widest point, the height to the bottom of the reservoir shall prevail.

(3) Set the net. According to the living habits of fish, nets are laid on the spillway of reservoir or other fish migration channels, relying on the impact of current or artificial driving, forcing fish swimming near the net mouth to fall into the net and be caught. Fixed Zhang net by the bottom net, wall net, figure net and cover net sewed together, was dustpan shape. Length 50 m, width 15 m, height 10 m~30m. The mesh is 3 cm, 5 cm, 8 cm, 12 cm and 16 cm, and is composed of 43 branches/10×3~15×3 polyethylene threads.

7.2 fishing method

Establish a skilled fishing professional team, according to the reservoir topography, topography and fish activity rules, adopt "catch, stop, stab, open" joint fishing method to catch adult fish. Process: net-fish-into the live fish boat-landing. Listing specifications according to market demand, do reasonable fishing, catch large and keep small.

Due to the different depths of reservoir water, fishing with only one kind of net has a low fishing rate, and some species of fish may not be caught. The operation method is called "catch, block, stab, Zhang (or pull)" combined fishing method. "Catch up" is to catch up with a three-layer gill net or drag a whiteboard with a boat. The aim is to lure fish into fishing areas by scaring and driving them away. The order of catching fish is from inside to outside, from shallow water to deep water, floating gill net and sinking gill net are used alternately, and they are pushed forward in turn. The net is laid horizontally and vertically. The net is perpendicular to the bank of the reservoir. The net is laid horizontally at intervals of 50 m. The water surface is crossed. One or two places are caught in one morning or one afternoon. When the net is completely laid, the net is placed along the last side of the net to isolate the area that has been caught from the area where fish have not been caught. "Block" is to block the fish in the fishing area. As the thorn netted forward, the block netted forward. "Spike" is to use three layers of gill nets to hang gill nets inside and outside the fishing area to catch fish that have not been driven into the net. "Zhang" or "pull" is to set the net in advance in the fishing area, wait for the fish to net, catch the fish, or use the net to pull the fish in a small range. The net is usually laid in the evening and closed the next morning. Operation principle: unified command, clear division of labor; watch fish net, aim to catch; seal before catch, fish channel unblocked; fish net dense, quick victory.