The migration of Huangyu has reached its peak, and the water area of Qinghai Lake has reached its largest value in nearly a decade. Protection | Qinghai Lake | Huangyu

CCTV News: Huangyu is a core species in the symbiotic ecosystem of "grass river lake fish bird" in Qinghai Lake. If there were no Huangyu, the water quality of Qinghai Lake and the migration and reproduction of birds would be seriously affected and destroyed. So, what kind of fish is Huangyu? Why does it exhibit migratory behavior?

Huangyu is named after the Huangshui River that flows through the territory of Qinghai Province. In fact, its real name is Qinghai Lake Naked Carp. Naked carp are carp without scales. Expert research suggests that Qinghai Lake was once connected to the Yellow River system, and the ancestor of Huangyu was the Yellow River carp, which originally had scales. About 130000 years ago, Qinghai Lake became a closed lake due to geological movements, and later evolved into a saltwater lake. In order to adapt to the increasingly salty lake water, the scales of the Yellow River carp stranded in the Qinghai Lake basin gradually deteriorate, and their exposed skin is better used to expel salt and alkali from their bodies.

Qinghai Lake has a low water temperature and high salinity. The yellow croaker accounts for over 95% of the fish resources in Qinghai Lake, with very few other fish species. The yellow croaker also has very few feed organisms to eat, which makes its growth rate very slow.

Huangyu usually lives in Qinghai Lake, with an average depth of 18 meters. The high salt and alkali content in the water of Qinghai Lake inhibits the development of Huangyu's gonads. From May to August each year, mature Huangyu needs to swim to the freshwater of rivers such as Buha River, Quanji River, and Shaliu River that converge into Qinghai Lake to lay eggs, which forms a major wonder of Qinghai Lake - Huangyu migration.

In the late 1950s, the reserve of yellow croaker in Qinghai Lake reached 320000 tons. However, due to overfishing and environmental degradation, by 2002, the reserve of yellow croaker was less than 2600 tons. Since 1982, Qinghai Province has implemented six rounds of lake closure for fish farming, especially since January 2001, the three consecutive rounds of Huangyu "fishing ban" have allowed small fish to fully rest and recuperate. In order to ensure the smooth spawning of wild yellow croakers, some dams that hinder their migration have been demolished in the surrounding areas of Qinghai Lake, and they have been transformed into fish paths suitable for their migration. The local area also adopts the method of artificial breeding and releasing, and releases a large number of fish fry to Qinghai Lake every year. According to monitoring data in 2022, the reserve of Huangyu reached 114100 tons, which is 44 times higher than the initial protection period.

The water area of Qinghai Lake continues to expand to its maximum value in nearly a decade

Qinghai Lake is the largest inland saline lake in China and an important water body for maintaining ecological security in the northeast of the Qinghai Tibet Plateau. In recent years, the water area of Qinghai Lake has continued to increase and has reached its maximum value in nearly a decade.

Recently, the reporter learned from the Qinghai Provincial Ecological Environment Monitoring Center that as of September 2022, satellite remote sensing monitoring footage showed that the water area of Qinghai Lake reached 4557.95 square kilometers, an increase of 187.26 square kilometers from 2012, with an average water level rise of more than 3 meters, and the water area reaching its largest value since 2012.

According to the satellite remote sensing monitoring images of Qinghai Lake region provided by the center from 2012 to 2022, it is evident that the water area of Qinghai Lake has undergone changes in the past decade.

Through a series of ecological protection and management measures such as wetland protection, degraded grassland management, and terrestrial aquatic biodiversity protection over the years, the water quality of Qinghai Lake has been continuously improving, and the water ecology has been increasingly optimized. The Institute of Hydrobiology, Chinese Academy of Sciences, has monitored the water quality of Qinghai Lake for many years.

Li Xiaohui, doctoral candidate of Institute of Hydrobiology, Chinese Academy of Sciences: According to the data we have accumulated for more than ten years, with the rise of water level, the salinity of the lake has dropped from 12 to 10 per thousand. Although the aquatic ecosystem of Qinghai Lake is relatively single, these populations are still concentrated in those who prefer clean water bodies, indicating that the water quality of the entire Qinghai Lake is still relatively stable and good.

Qinghai Lake is a natural barrier to control the spread of desertification from the west to the east. The increase in the area of Qinghai Lake is of great significance for curbing desertification and ecological protection in the surrounding areas. After the increase in the water area of Qinghai Lake, the previously exposed sandy land in the sand island area of Qinghai Lake was submerged by the lake water, forming a large wetland, providing an excellent breeding and habitat for various waterfowl such as black necked cranes, swans, and spotted geese. Some migratory birds adapt to the expanding wetland area and gradually improving ecological environment of Qinghai Lake, becoming the resident birds of Qinghai Lake.

The migratory yellow fish and migratory birds together weave a lively and harmonious ecological scene. With the arrival of the peak migration of Huangyu, there are many exciting ecological stories happening around Qinghai Lake.