Introduction:
Silver carp is endemic to the Yangtze River basin, where it is abundant and far larger in size than in other regions.
In 2017, a Taiwanese angler caught a large silver carp weighing 82 pounds, which attracted widespread attention. Why are silver carp in the Yangtze River so large and plentiful? This article will analyze and discuss from the following levels.
First, environmental factors
1.1 Water Quality
The Yangtze River is the longest river in China, with a basin area of more than 1.8 million square kilometers, which is an important support for China's economic development, but it also has serious pollution problems.
However, the number of silver carp in the Yangtze River has maintained an alarming increase, and the water quality has not had a significant impact on the survival and reproduction of silver carp.
1.2 Water temperature
Silver carp in the Yangtze River Basin has a certain ability to withstand high temperature, which is related to the high temperature and humid climate environment in the Yangtze River region. Yangtze River silver carp can still maintain vitality under high temperatures, will not die, and can also promote its growth and development.
Second, food factors
2.1 Aquatic vegetation
The Yangtze River basin has vast lakes and water surfaces, and sufficient aquatic vegetation provides rich food resources for silver carp. Silver carp in the Yangtze River basin feed on microscopic organisms such as aquatic plants, and these aquatic vegetation play an important role in the growth of silver carp.
2.2 Aquaculture
China's aquaculture industry is developing rapidly, and aquaculture in the Yangtze River area has a certain proportion, which also directly affects the number and individual size of silver carp. Aquaculture wastes and feed residues have become a source of nutrients for silver carp growth, indirectly promoting the growth of silver carp.
Third, the human factor
3.1 Protection Policy
The Chinese government has invested a lot of money and manpower in the protection of the natural environment in the Yangtze River Basin, and has established a series of nature reserves and ecological demonstration areas to protect and restore the natural ecological environment of the region.
These policy measures have directly contributed to the increase in the number of silver carp, and at the same time increased the individual size of silver carp.
3.2 Fishing culture
The Yangtze River region has a strong fishing culture, and local anglers also have a love and awareness of silver carp.
In their daily recreational activities, these anglers not only learned a lot of bait matching skills and fish ecological knowledge, but also constantly explored the growth law and breeding links of silver carp through their own practical experience.
At the same time, their fishing behavior also plays a protective role, maintaining the population and individual size of local silver carp.
Summary:
In summary, the large number and individual size of silver carp in the Yangtze River are higher than those in other regions, mainly due to the multiple effects of its environment, food and human factors.
The aquatic vegetation, aquaculture and fishing culture of the Yangtze River region have provided nutrition and protection for the growth of silver carp in the Yangtze River, and the government's environmental protection policies have also created a good environment for the growth of silver carp population.