Can crabs be raised in the desert? Yes, they are coming to your table soon!

Produced by: Science Popularization China

Author: Shi Chang (PhD in Physical Chemistry)

Producer: China Science Expo

As the autumn wind blows, crabs start to itch. Crab lovers are delighted and quickly place orders for several pounds of large crabs, looking forward to tasting them after get off work. But did you know that these fat and roe crabs may actually come from a place that seems to have nothing to do with crabs - the Taklimakan Desert?

Desert Crab

(Photo source: veer photo gallery)

It is reported that in April this year, Hotan County, located on the edge of the Taklimakan Desert, airlifted about 30,000 tons of crab seedlings from Jiangsu. After more than four months of breeding at the Hotan County aquaculture base, these crab seedlings are ready to be caught and put on the table!

We all know that aquatic organisms like crabs cannot live without water, so what other conditions are required for crab farming?

First of all, water also needs to meet certain conditions: Crab farming requires clean, oxygen-rich water, and the water's pH, ammonia nitrogen, nitrite and other indicators need to be controlled within an appropriate range to ensure the growth and health of the crabs. For example, crab farming in acidic water will affect its calcium absorption and blood circulation.

Environmental conditions: Crabs prefer muddy bottoms, rich aquatic plants and slow-flowing water. In addition, crabs also have certain requirements for light and temperature, requiring appropriate light intensity and temperature range.

Feed conditions: Crabs are omnivorous animals and need to take in animal and plant feed. This is why crabs can be raised in rice fields. The fish, shrimp, grass and other plants in the rice fields provide sufficient nutrients for crabs.

Crab

(Photo source: veer photo gallery)

Where does the water for breeding crabs in the desert come from?

In the process of breeding crabs in the desert, obtaining water is a crucial link. The water source for breeding crabs in the desert mainly comes from groundwater, river water diversion, rainwater collection, etc.

Groundwater in desert areas mainly comes from the melting of snow and the infiltration of rainfall in the Tianshan Mountains and Kunlun Mountains. These water sources form rich aquifers under the desert. Local people usually obtain groundwater by digging wells or drilling holes. These groundwaters not only provide living water for local residents, but also become an important water source for desert crab farming.

At the same time, the Yulong Kashi River and other rivers flow through the Hotan area on the edge of the Taklimakan Desert. During the flood season, the water from these rivers can be introduced into the breeding ponds to provide the necessary water for the crabs. In addition, although the annual precipitation in the desert area is extremely low, rainwater can still be collected and used during the rainy season. By building a rainwater collection system, a certain amount of water resources can be accumulated in a short period of time to supplement the water volume of the breeding ponds.

In the process of crab farming in the desert, recycling and water-saving technologies are usually used to improve the utilization efficiency of water resources. For example, by building an ecological circulation system, the aquaculture wastewater is treated and reused for aquaculture or irrigation; at the same time, water-saving irrigation methods such as drip irrigation and sprinkler irrigation are used to reduce water evaporation and waste, so as to ensure the sustainable development of crab farming.

Desert water

(Photo source: veer photo gallery)

Raising crabs in the desert, is it because there are not enough crabs to eat?

Xinjiang is a province with a relatively high proportion of saline-alkali land in China, accounting for about 30% of the country's saline-alkali land area. According to relevant surveys, in the past 50 years, Xinjiang has reclaimed more than 50 million mu of saline-alkali land. The main components of Xinjiang's saline-alkali land are sodium chloride, sodium sulfate, sodium carbonate, calcium and magnesium.

The weak alkalinity of the soil makes it difficult for general crops and plants to survive, but it is a favorable condition for crab farming. The salt in the saline-alkali land can meet the mineral needs of crabs for growth, becoming a "unique nutrient" for crab growth. Large areas of saline-alkali land can also meet the density requirements for crab farming, and have good innate conditions.

In addition, aquaculture can improve the local ecological environment of the desert to a certain extent. Crabs eat benthic organisms and organic debris during their growth, which helps reduce pollutants and eutrophication in the water. At the same time, the crabs' ability to dig soil can also help improve soil structure, increase vegetation coverage, and reduce wind and sand erosion.

Crab digging

(Photo source: veer photo gallery)

What else can the desert support?

Drought-tolerant insects

Edible insects that require less water resources, such as locusts and crickets, have high nutritional value and can be used as a source of food or feed. In desert environments, these insects can be farmed on a large scale through appropriate breeding techniques and management measures.

cricket

(Photo source: veer photo gallery)

Drought-tolerant camels

Camels are typical animals in the desert. They can survive for a long time without drinking water and in extreme environments. Therefore, breeding camels in desert areas is not only highly adaptable, but also the camel's wool, meat, milk and other products also have high economic value.

camel

(Photo source: veer photo gallery)

Desert shrimp farming

Raising shrimp in the desert is a challenging and innovative farming method, but with the support of modern technology, this idea has been successfully realized. Water resources in desert areas are scarce. By utilizing underground saline water or water from the Yellow River, and undergoing desalination and purification, a water quality environment suitable for shrimp growth can be simulated. By controlling water parameters such as salinity, pH value, and hardness, the water quality is ensured to be pure and suitable for shrimp growth.

At the same time, a shrimp-vegetable symbiotic system is constructed, where shrimp excrement and leftover feed will be decomposed by microorganisms and converted into nutrients that can be absorbed by plants. The growth of plants can absorb harmful substances such as nitrogen and phosphorus in the water, forming a miniature ecosystem.

shrimp

(Photo source: veer photo gallery)

Conclusion

Although the desert is known for its extreme environmental conditions, through advanced technology, careful environmental control and unremitting efforts, humans have successfully cultivated edible products in this seemingly unsuitable land for life.

The practice of raising crabs in the desert is not only an expansion of the boundaries of traditional farming, but also another innovation in resource utilization. With the advancement of science and technology and the enhancement of people's awareness of environmental protection, we look forward to seeing more such successful cases emerge and contribute more to human food safety and economic development!

References:

1. Zhou Xiaowei, Lu Changmei. A brief discussion on crab farming methods and water quality management[J]. China Agricultural Information, 2014(1S):1.DOI:10.3969/j.issn.1672-0423.2014.01.115.

2. Wu Jianjun. Desert fish farming and marine integrated aquaculture in Israel[J]. World Agriculture, 1995(12):3.DOI:CNKI:SUN:SJNY.0.1995-12-018.

3. Guo Wanping, Zhao Jing, Luan Chunyu, et al. Molecular biological identification of bacterial species in composite microbial powder for aquaculture[J]. Chinese Journal of Veterinary Drugs, 2017, 51(6):10.DOI:10.11751/ISSN.1002-1280.2017.6.02.