Dotted silver bass.
Big-tipped carp. Sun Zhi idly photographed
The fish in the surrounding rivers have seen less, which has worried many citizens. At present, with the gradual improvement of the aquatic ecological environment, the wild fish species living in Beijing and its neighboring areas are slowly picking up. According to the data collected by the investigation team of the Institute of Zoology of the Chinese Academy of Sciences, the species of wild indigenous fish in Beijing are showing a rebound trend in the Huaijiu River, Huaisha River, Yongding River, Chaobai River and other watersheds, and wild fish such as largefin carp, dotted silver catfish, stick flower catfish and northern loach are returning to the river.
In the middle of summer, the green tree-shrouded suburb of Beijing is cooler than the urban area. The breeze on the shore is blowing willows, and the open water of the Huaisha River is sparkling. Bowed, the crystal clear water of the river, from time to time there are toothpick-sized wild fry, swimming freely among the pebble aquatic plants.
The Huaisha River is an important river in the upper reaches of the Huairou Reservoir, passing from south to north through the oral village of Qiaozi Town. "In the early years, there were houses everywhere on both sides of the river." He Dongwei, deputy secretary of the party branch of Koukou Village, grew up by the Huaisha River and witnessed every change here. "Because of its proximity to the Huairou Reservoir, in the past, many villagers set up small courtyards in the open space on the bank of the river, and more than a dozen interception dams have appeared in the river channel to raise fish in enclosures for tourists to fish." The river is locked by a series of interception dams, it cannot flow, and the water quality is getting worse and worse every day. ”
In recent years, with the three important rivers in the upper and lower reaches of the Huairou Reservoir, the Huaisha River, the Huaijiu River and the Yanqi River, the aquaculture industry has been completely withdrawn, the dams and dams have been dismantled and the private construction on both sides of the river has been dismantled, and the silt at the bottom of the river has been cleaned up. "The water has flowed, and the ecological environment has changed significantly." He Dongwei was delighted to find that the "white striped fish" and "milk bun fish" commonly found in the Huaisha River when he was a child swam back after many years.
In the Aquatic Wildlife Nature Reserve between the Huaijiu River and the Huaisha River, Zhao Yahui, an associate researcher at the Institute of Zoology of the Chinese Academy of Sciences and an expert in ichthyology, found through field investigation that the species of wild indigenous fish in Beijing are showing a rebound trend. "In 2004, I took students to do a detailed survey here once a month and collected 21 species of fish; in 2017, spring, summer and autumn were only visited once, and the frequency of the survey was low, but 33 species of fish were found, an increase of 12 species compared with before, such as largefin carp, dotted silver catfish, stick flower catfish, northern loach and so on."
A similar situation also occurred in Mentougou and Yanqing, where the Yongding River flows. From 2016 to 2018, Zhao Yahui and his scientific research team collected 25 species of fish through fixed-point collection. Compared with the data collected from 2002 to 2010, there are 9 species, and the Chaobai River Basin, where the water environment is better protected, fish diversity has been maintained at a relatively high level for more than a decade.
Between 2002 and 2010, Zhao Yahui conducted continuous field surveys and collections of wild fish in and around Beijing, combined with fish specimens from the National Zoological Museum collection of the Institute of Zoology of the Chinese Academy of Sciences, to calculate that there were 85 species of native fish in Beijing before 1930 – which was also the period when Beijing had the largest number of fish species, surpassing all freshwater fish species in Europe combined. By 2010, the number of fish species had dropped to 41, and nearly half of the native wild fish species had disappeared.
In the past two years, Zhao Yahui has seen gratifying changes. "Fish are an important part of aquatic ecosystems, and the diversity and spatial distribution of fish can reflect the quality of water bodies to a large extent." Zhao Yahui told reporters, "Beijing has alleviated the shortage of water resources through a series of measures such as the south-to-north water diversion and the introduction of yellow into Beijing. Relevant authorities are also paying more and more attention to water protection, water treatment and other issues. The data shows that beijing's ecological environment water consumption is rising every year, and ecological water consumption is second only to domestic water. (Source: Beijing Daily Zhang Xiaoying)