Detailed Explanation of the Comprehensive Ecological Fishery Technology Model in Northern China

Ecological fishery refers to a farming model based on the principle of symbiotic complementarity between fish and other organisms, utilizing the land-water material circulation system, and adopting corresponding technical and management measures to maintain ecological balance and improve farming efficiency. Developing ecological fishery can make full use of local resources, recycle waste, save energy, improve comprehensive ecological benefits, and achieve sustainable development of fisheries.

1. Fish-Grass Model

The fish-grass combination type is a relatively common @#@233@#@ model, generally with 200-300 sq m of embankment or pond-side forage plots for every 600 sq m of water surface, planting high-yield, high-quality green forage such as cup plant (Silphium perfoliatum), Sudan grass (Sorghum sudanense), hybrid dock (Rumex spp.), and alfalfa (Medicago sativa), providing abundant high-quality green forage for herbivorous fish, saving concentrated feed, reducing costs, and increasing output. In addition, aquatic plants such as rootless duckweed (Wolffia arrhiza) and duckweed (Lemna spp.) can be planted in ditches around the pond embankment, which not only purifies the water body but also provides high-quality palatable forage for fish.

2. Fish-Pig Model

Raising fish in combination with @#@227@#@ is an effective ecological fish farming model. This approach: first, properly composted and fermented pig manure can be directly put into fish ponds to fertilize the water for fish farming; second, pig manure is used to grow grass, raise @#@254@#@, and undergo anaerobic fermentation to produce biogas as fuel, and then the grass, earthworms, biogas slurry, and biogas residue are used to feed fish, reducing the cost of fish and pig farming and increasing benefits. Generally, 5-10 pigs are needed for every 667 sq m of water surface. One pig raised for 4 months excretes 1.5-1.8 tons of manure and urine, and on average 40 kg of pig manure can produce 1 kg of fish.

3. Fish-Chicken (Duck) Model

Chickens (ducks) have a relatively low feed utilization rate, and their manure contains many incompletely digested nutrients that can be utilized by fish. Each chicken (duck) produces 30-50 kg of manure per year, which can increase fresh fish production by 1-1.5 kg. At the same time, chickens can peck at pests along the pond edge, and ducks can feed on dead fish and aquatic insects, churn the pond mud to promote decomposition of organic matter, accelerate material circulation, and also increase dissolved oxygen in the water body and break the thermal stratification phenomenon. The combination of fish and chickens (ducks) can create mutual benefits. Generally, raising 50-100 chickens (ducks) per 667 sq m of water surface is appropriate.

4. Fish-Mulberry-Silkworm Model

The fish-mulberry-silkworm combination mainly involves planting mulberry on pond embankments, interplanting vegetables and grass among the mulberry, feeding mulberry leaves to silkworms, feeding silkworm droppings and vegetables and grass to fish, and using pond mud as fertilizer for mulberry, vegetables, and grass, so as to achieve material circulation and obtain the effect of mutual benefit among fish, mulberry, and silkworms with joint increase in production.

5. Fish-Rice Model

The fish-rice combination develops the originally simple rice field ecosystem toward a diversified ecosystem and multi-level material recycling utilization, giving play to the mutually beneficial symbiotic effect of rice and fish, and achieving the goal of increasing both rice and fish production.

6. Fish-Livestock-Poultry Model

Build livestock pens and poultry houses on the open space beside fish ponds, use poultry manure to feed pigs, and use livestock and poultry manure to fertilize water for fish farming. In the fish-pig-chicken combination, 3-5 pigs and @#@230@#@ 50-80 chickens can be raised per 667 sq m of water surface. In the fish-cattle-chicken combination, @#@228@#@ 1-2 cattle and 30-50 chickens can be raised per 667 sq m of water surface, with 667-1300 sq m of grass planted.

7. Planting-Farming-Processing Model

The planting-farming-processing combination type is a currently emerging multi-level and diversified comprehensive utilization model, and is a very effective way of material circulation and energy flow that integrates planting, fish farming, and processing.

Developing comprehensive ecological fishery according to local conditions can achieve effective allocation of resources, attain both ecological and economic benefits, and promote the virtuous cycle and sustainable development of fishery production.