Source: People's Daily - People's Daily
Erhai, Dali, Yunnan. Photo by Xinhua News Agency reporter Hu Chao
Core reading
Indigenous fish, i.e. native fish, are also known as native fish species. Compared with exotic fish species, indigenous fish tend to have higher habitat requirements due to their relatively narrow distribution area. The protection of indigenous fish is both the protection of aquatic ecology and the protection of biodiversity.
In Yunnan, the ongoing investigation of indigenous fish resources, artificial domestication and breeding, in situ conservation and ex situ conservation have become effective means of protecting these fish. With ecological improvements, in some places indigenous fish stocks have been restored to some extent.
"Do you have any fish here?"
"Grass carp, carp crucian carp, yellow eel loach."
In Yunnan, this is the common answer in many places. Native fish are not often mentioned.
The land of Yunling is scattered with six major river systems such as the Yangtze River, the Pearl River and the Lancang River, and nine plateau lakes such as Dianchi Lake, Erhai Lake and Fuxian Lake. As of 2019, Yunnan Province has recorded 629 species and subspecies of freshwater fish, accounting for 39.9% of the total number of freshwater fish species in the country, of which 594 are indigenous species and 255 are endemic to Yunnan.
How can indigenous fish species be effectively protected?
Some of the indigenous fish species sources in natural ponds and caves have preserved hope for population recovery
Affected by water pollution, the Dianchi lake golden ray catfish was once difficult to find in dianchi lake, fortunately, the Dianchi lake golden ray catfish distributed in several natural ponds in the Dianchi lake system and the streams into the lake retained the seed source of this fish; in Fuxian Lake, since the introduction of Taihu silver fish in the 1980s and 1990s, the production of anti-wave fish has fallen off a cliff; in Xingyun Lake, because of hybridization with foreign carp, the head of the national second-level key protected wild animal bighead carp is getting smaller; and in the Erhai Sea, the once main fish species "bowfish" is now rare to see...
Not only the "four famous fish in Yunnan", in the nine plateau lakes such as Dianchi Lake, Qilu Lake and Cheng Hai in Yunnan Province, the fish community has been dominated by a variety of indigenous fish. However, in the past three or five decades, the number of exotic fish species has increased significantly.
The situation of indigenous fish populations in rivers is also not optimistic. "When I was a child, I wanted to eat fish, and I could get it with a fork; in previous years, it was difficult to catch it under the net." In Deze Village, Deze Township, Zhanyi District, Qujing City, Yunnan Province, Bao Qingmin, who grew up along the Niulan River, saw that the number of indigenous fish was decreasing, and after retirement, he began to try to domesticate indigenous fish artificially.
Water pollution in some watersheds for a period of time may affect a variety of fish in small watersheds. In Dahe Town, Fuyuan County, Qujing City, after the improvement of water quality in recent years, indigenous fish began to return to the river from natural ponds and underground rivers. "A few years ago, the upstream coal washing sewage was discharged straight, and no fish could be found in the river." Chen Feng, director of the Fuyuan County Aquatic Products Workstation, said that fortunately, natural ponds and caves have retained some indigenous fish seed sources, which has preserved hope for the recovery of indigenous fish stocks.
Experts believe that a more comprehensive understanding of the distribution of indigenous fish, especially at the outlet of underground dark rivers, natural ponds, etc., whether indigenous fish species are still retained is inseparable from more in-depth investigation.
Some of the natural populations of indigenous fish have recovered to some extent
With the increase in ecological awareness, some natural ponds with indigenous fish activities have been more effectively protected.
In the natural pond of Jinhu Village, Fengyi Town, Dali City, there are still "bowfish" running through it. Zhang Furong, a village cadre in Jinhu Village, introduced that when he was a child, he saw more fish than now, but he did not know that this was the famous "bow fish". After the local government learned that these fish were "bowfish", a fence was built for protection. Meng Zhirong, a senior agronomist at the Dali Bai Autonomous Prefecture Fishery Workstation, also left a special phone number with Zhang Furong - to protect such a small population, it is inseparable from the cooperation of grass-roots cadres.
"In situ conservation protects both indigenous fish and their habitats, making it possible to achieve the natural restoration of indigenous fish stocks. Otherwise, even if the artificial breeding of indigenous fish is achieved, if the original territory has been destroyed, where should the indigenous fish be released? Chen Xiaoyong, a researcher at the Kunming Institute of Zoology of the Chinese Academy of Sciences, suggested that a stricter protection system should be implemented for areas where indigenous fish are more concentrated or where fish spawning grounds are concentrated, especially to increase the crackdown on illegal fishing practices such as electric fish, fried fish, and the use of "no-household nets".
In recent years, the improvement of water quality in the nine plateau lakes in Yunnan has also provided the possibility for the return of some indigenous fish. In the Dianchi Lake system, certain sections of the Panlong River have monitored the population of the Dianchi lake golden-threaded catfish.
In the Erhai Sea, the carp, spring carp and Yunnan split-bellied fish are still distributed; in Fuxian Lake, the natural population of anti-wave fish has been protected and restored to a certain extent...
"Indigenous fish cannot wait until they are endangered before domestication and breeding, otherwise once technological research and development lags behind the rate of fish population disappearance, the losses will be immeasurable." Meng Zhirong said that the protection of indigenous fish is not only to protect a certain fish or lake ecosystem, but also to protect biodiversity and protect characteristic biological resources, which has incalculable value.
Domestication and breeding provides a source of seed for the recovery of wild populations
"In situ conservation is not a substitute for ex situ conservation." In Meng Zhirong's view, ex situ conservation has a unique value for the conservation of germplasm resources. In recent years, whether it is a government department or a scientific research unit, more and more forces have participated in the domestication and breeding of indigenous fish. Different from the relatively small number of breeding individuals of mammals, once indigenous fish break through artificial domestication and breeding technology, a pair of broodstock can breed thousands of offspring, and artificial intervention can rapidly expand the population, thereby providing a source for wild population recovery.
"Many indigenous fish have unique resistances and are particularly valuable for crossbred breeding. The genes carried by indigenous fish are of greater value to humans, especially to aquaculture! At present, a carp that accounts for nearly 30% of the commercial carp farming market has the gene of the indigenous fish Yuanjiang carp. When he said this, Meng Zhirong raised his voice.
Under the intervention of man, in just 6 years, the "bowfish" in the Tuanshan Carp Spring in Songqu Village, Youshou Town, Eryuan County, Dali Prefecture, has increased from dozens to tens of thousands. According to the relevant person in charge of Dali Jiangdong Biotechnology Co., Ltd., relying on the technical support of the Kunming Institute of Zoology of the Chinese Academy of Sciences, the number of "bowfish" population has increased significantly.
Today, not only in Eryuan, but also in a breeding base downstream of the Haima Zhen Reservoir in Yiliang County, Kunming City, dozens of ponds are mixed with dozens of indigenous fish such as anti-wave fish, short-bearded schipped fish, large-headed carp, dianchi lake golden rayfish and so on. Not only has the seed source of these indigenous fish been preserved here, but also the large-scale cultivation of wave-resistant fish has been successfully realized.
People's Daily ( 2021-09-02 13th edition)