Xinhua Daily Telegraph
With the implementation of the great protection of the Yangtze River, especially the ten-year ban on fishing in the Yangtze River, the trend of significant decline of some rare flagship species in the Yangtze River has been initially curbed. However, the conservation situation is still not optimistic: white sturgeon, white sturgeon, anchovies, anchovies, etc. have been extinct for many years, Chinese sturgeon has not found natural reproduction for 4 consecutive years, the wild population of Yangtze River sturgeon is almost extinct, and the Yangtze River finless porpoise is critically endangered...
A Yangtze River finless porpoise swims in the waters of the Ganjiang River in Nanchang, September 3, 2021 (drone photo). Photo by Liu Zhankun, a reporter from China News Service
Experts believe that the ten-year ban on fishing in the Yangtze River is a big step in the protection of aquatic biodiversity in the Yangtze River, and it is necessary to further consolidate and expand the results of the fishing ban, integrate resources to form a joint force, take comprehensive measures to increase the "seed preservation" of endangered aquatic organisms, vigorously carry out population reconstruction research and practice, and strive to make the flagship species that has lived in the Yangtze River for more than 100 million years turn into safety.
Rare flagship species are both mixed and woeful
According to the central deployment, from 00:00 on January 1, 2021, the key waters of the Yangtze River Basin will implement a "ten-year fishing ban". More than 1/3 of the tasks of banning fishing in the Yangtze River Basin are in Hubei, and more than 26,000 Hubei fishermen bid farewell to the "rivers and lakes" and turned ashore.
Human beings care for nature, and nature feeds back human beings. The "ten-year fishing ban" on the Yangtze River has been fully implemented for more than half a year, and there are more fish and porpoises in the northern section of the Yangtze River and the Han River, and some rare fish that have not been seen for many years have reappeared.
In June, researchers surveyed and monitored a knife fish in the Jiayu section of the Yangtze River, which was the second time in 30 years that the knife fish was traced back to the northern section of the Yangtze River. Subsequently, some people filmed a video of a porpoise jumping out of the Qianjiang section of the Han River, which was the first time in nearly 30 years that a finless porpoise activity was discovered in Qianjiang City, Hubei Province.
Since the beginning of this year, the Yangtze River finless porpoise has repeatedly appeared in the northern section of the Yangtze River. In Yichang, videos of finless porpoises traveling in groups, finless porpoise mothers and children traveling together, and pregnant finless porpoises swimming alone have attracted a lot of attention; in Wuhan, the river section of the urban area has repeatedly appeared in the river section, attracting the attention of government departments, scientific research institutions and citizens; in Jingzhou, the porpoise group has been expanding, becoming a model for the ex-situ protection of finless porpoises. Finless porpoises are found in Nanjing, Zhenjiang and other places along the Yangtze River, as well as in Tongjiang Lakes such as Dongting Lake and Poyang Lake, and the number of populations and the high frequency of occurrence are exciting.
Experts said that the appearance of finless porpoises reflects the improvement of the ecological environment brought about by the ban on fishing in the Yangtze and Han rivers. "Finless porpoises staple small fish, and the 'ten-year ban on fishing' in the Yangtze River has increased the bait of finless porpoises, providing a guarantee for the return of finless porpoises." Wang Kexiong, a researcher at the Institute of Hydrobiology of the Chinese Academy of Sciences, said.
Finless porpoises appear frequently, red-billed gulls appear in flocks, elk populations continue to expand, and wintering migratory birds in important lakes and wetlands such as Dongting Lake and Poyang Lake are increasing year by year... The conservation of biodiversity in the Yangtze River has achieved remarkable results, and the protection of the Yangtze River has curbed the trend of accelerated environmental deterioration to a certain extent.
However, there are still many rare flagship species of the Yangtze River in a worrying situation. At the end of 2019, in a paper published by Wei Qiwei, a researcher at the Yangtze River Fisheries Research Institute of the Chinese Academy of Fishery Sciences, the conclusion that "the Yangtze River white sturgeon is extinct" has aroused widespread concern. Wei Qiwei said that after 2003, the white sturgeon has disappeared. The extinction conclusions have undergone long-term rigorous scientific demonstration and have been assessed by the International Union for Conservation of Nature.
On April 22, 2020, the "2020 Three Gorges Chinese Sturgeon Release Activity" was held at the rare fish release site in Yichang, Hubei Province. Staff are releasing Chinese sturgeon. According to Visual China.
The extinction of the white sturgeon means that another endemic species in the Yangtze River has disappeared, and the only 4 national first-class protected animals in the yangtze river aquatic flagship species have almost been "completely destroyed". Zou Guiwei, director of the Yangtze River Fisheries Research Institute of the Chinese Academy of Fishery Sciences, introduced that the white sturgeon was declared functionally extinct in 2007 before the white sturgeon; only 20 wild individuals of the Yangtze River sturgeon remained; in 2013, 2015, 2017, 2018, 2019 and 2020, the natural breeding activities of the Chinese sturgeon were interrupted, and the species continued to be in danger.
The situation of the finless porpoise, which was recently upgraded to a national first-class protected animal, is not optimistic. The results of the 2017 scientific expedition showed that the population of finless porpoises was about 1012, which was only half of the giant pandas. Many experts believe that in recent years, the finless porpoise has been more active than before, but whether the number has increased, it is necessary to organize a scientific expedition to evaluate. To be sure, the critically endangered situation of finless porpoises has not changed and remains severe.
In addition, Zou Guiwei introduced that compared with the historical distribution of fish, there are 124 species of fish that have been distributed in the key forbidden waters of the Yangtze River and have not been collected in the past 4 years, belonging to 9 orders and 16 families, accounting for 29% of the total number of species, including 75 species endemic to the Yangtze River, 32 endangered species, and 2 species of nationally protected animals.
"The ecological and biodiversity issues of the Yangtze River are very complex, and the decline and even extinction of species reflect the state of the ecosystem, but species extinction is a cumulative process and cannot fully reflect the ecological status quo of the Yangtze River in recent years." Chang Jianbo, director of the Institute of Water Ecology of the School of Water Resources and Hydropower of Wuhan University, said, "The protection of the Yangtze River is long-term, and ecological changes are also accumulated for a long time. ”
Perspective is the three main means of protection
Wei Qiwei said that in just a few decades, species such as white sturgeon, white sturgeon, anchovies and anchovies that have survived in the Yangtze River for thousands of years have gone extinct, indicating that the ecosystem has deteriorated sharply in previous years. "The deceased is gone. The most important thing is to figure out the reasons for the extinction of the species and find a way to keep the remaining endangered species. ”
In situ protection, ex situ protection, and breeding and stocking are the main means for the protection of rare flagship species in the Yangtze River. For decades, relevant departments, scientific research units and enterprises have continued to exert efforts, especially since 2015, the Ministry of Agriculture and Rural Affairs has successively issued the "Chinese Sturgeon Rescue Action Plan (2015-2030)", "Yangtze River Finless Porpoise Rescue Action Plan (2016-2025)", "Yangtze River Sturgeon (Dashi Sturgeon) Rescue Action Plan (2018-2035)". Finless porpoise ex situ protection, Chinese sturgeon, Yangtze River sturgeon artificial breeding results are obvious.
"Artificial breeding has successfully saved the Yangtze River sturgeon and brought hope for population reconstruction." Zou Guiwei said.
However, the Xinhua Daily Telegraph reporter's investigation found that the current three main protection methods have obvious effects, but there are also some problems, and the situation of species protection is still not optimistic.
In terms of in situ protection, human interference of the Yangtze River water ecosystem is inevitable, and the aquatic biological nature reserve and aquatic biological protection belong to different departments of management, and the management of the protected area is difficult; due to the impact of human activities such as dam construction, shipping, sand dredging, lake encirclement, and surface hardening, the Yangtze River water ecosystem has changed significantly. Dam barriers, reservoir construction lead to regional hydrological changes, hydraulic and waterway construction caused by riverbed changes, bringing about changes in the ecological pattern that are difficult to eliminate.
Yao Weizhi, director of the Fishery Resources and Environment Research Center of Southwest University, said that hydropower development has been carried out in the main stream of the upper reaches of the Yangtze River and most of the primary and secondary tributaries, the natural connection of the river has been blocked, and the fishery department and scientific research units have carried out habitat restoration experiments such as setting up artificial fish nests and artificial reefs. "However, due to the lack of mandatory norms or standards, the one-sided pursuit of economic benefits by power generation enterprises, the lack of relevant technical support, the lack of funds and other reasons, among the most important measures for habitat restoration, the restoration of river connectivity has not yet started, the cascading water intake of reservoirs is still piloting, and the ecological flow of power stations has basically not been implemented." Yao Weizhi said.
In terms of ex situ protection, although the Chinese sturgeon and the Yangtze River sturgeon have successively achieved full artificial breeding, and breakthroughs have been made in ex situ protection technology, the artificial seed preservation site, artificial and capital investment is large, and it is difficult to protect the seeds. According to experts, there are 2,000 Chinese sturgeon in the 10-year-old generation of the country, with a serious small physique and a low proportion of maturity; 2,000 broodstock in the Yangtze River sturgeon generation and 1,000 broodstock in the second generation of the Yangtze River sturgeon, and the breeding and utilization are not enough.
Wang Ding, a well-known porpoise research expert and researcher at the Institute of Hydrobiology of the Chinese Academy of Sciences, said that the ex situ conservation of finless porpoises has achieved remarkable results, and the research and artificial breeding of finless porpoises at the Institute of Aquatic Sciences of the Chinese Academy of Sciences have made great progress, but the existing research base facilities are old and too small to meet the needs. Some of the three porpoise ex-situ protected areas in the main stream of the Yangtze River have been isolated from the main stream of the Yangtze River, and the main stream has basically lost the function of replenishing water sources, improving water quality and supplementing early fish resources in the ex-situ protected areas.
The scale of breeding and stocking is seriously insufficient and the effect is not good. Wei Qi, secretary of the party group of the Chinese Academy of Fishery Sciences, said that the scale of breeding and stocking of Chinese sturgeon is far from meeting the needs. Since the realization of the natural breeding of Chinese sturgeon under Gezhouba in 1983, about 7 million have been released into the Yangtze River, of which 50% are newly hatched Chinese sturgeon seedlings, and the proliferation effect is limited. "The state treasury has not specifically allocated funds for the artificial breeding and stocking of Chinese sturgeon, and the funds for the release of rare aquatic animals have been reduced year by year."
"The case of the Chinese sturgeon is frustrating, busy sweating, and it doesn't work." Chang Jianbo said, "Judging from the current monitoring, the 7 million tails that were previously released basically have no reproductive ability. In the past, the breeding and stocking of the scene could only play a role in publicity and education, and had little effect on population recovery. ”
"Write" good implementation of the article
The interviewed experts believe that with the continuous deepening of the protection of the Yangtze River, the governments at all levels and the public have more and more understanding of the protection of rare species in the Yangtze River, and the protection path has been basically clear, and what needs to be done now is to further integrate resources, strengthen scientific research, do a good job in implementing the article, and implement some effective measures that have been tested in practice.
Rationalize institutional mechanisms, strengthen scientific research, and integrate resources to form a synergy. Many experts believe that human beings live by water, aquatic organisms are difficult to isolate and protect like terrestrial animals, and to increase the protection of key aquatic habitats, it is necessary to straighten out the relationship between habitats and species protection departments and form an organically integrated whole.
Chang Jianbo suggested that we should pay close attention to the research on the reconstruction of chinese sturgeon, Yangtze River sturgeon, finless porpoise and other population reconstruction, and innovate and carry out population reconstruction experiments; it is recommended to set up a Yangtze River laboratory to further integrate scientific research resources and provide strong scientific support for species protection.
Implement the ten-year ban on fishing on the Yangtze River and minimize the negative impact of human activities. Cao Wenxuan, an academician of the Chinese Academy of Sciences, said that the ten-year ban on fishing on the Yangtze River is a basic measure for the Yangtze River to recuperate and recuperate, and it is necessary to firmly grasp it and strictly prevent rebound.
Yao Weizhi suggested that the existing diversion power stations in each tributary should be forced to discharge ecological flow as required; the implementation of hierarchical water withdrawal to avoid the phenomenon of lack of oxidation and low temperature in the discharge of water under the diversion power station; and the restoration of the fish living environment of the diversion hydropower station should be carried out. "To rebuild the population and restore its early life history, we must harden and naturalize, and we must protect the wetland." Chang Jianbo said.
Adopt comprehensive measures to increase the intensity of "seed preservation". Chang Jianbo suggested establishing a scientific "seed preservation" plan for endangered aquatic organisms in order to rebuild their wild populations in a timely manner. Scientific research has shown that species such as Chinese sturgeon are sensitive to sound and light, and the only Chinese sturgeon spawning ground is too close to the urban area, on the one hand, it is necessary to try to control sound and light pollution, on the other hand, measures can be taken to open up new spawning grounds for Chinese sturgeon.
Experts call for the vigorous implementation of the action plan for the rescue of Chinese sturgeon, finless porpoises and Yangtze River sturgeon, "both thunder and rain", and implement the plan; it is necessary to increase manpower, funds, and policy guarantees, and carry out artificial breeding and breeding and stocking in a planned, step-by-step, and large-scale manner; we must adhere to the overall protection of the river basin ecosystem, adhere to the integrated and coordinated protection of grass, sand and ice in landscapes, forests, lakes, and lakes, and gradually restore the ecological environment of the Yangtze River.
(The original title was "Chinese sturgeon has not naturally multiplied for four consecutive years, when will the rare flagship species of the Yangtze River turn dangerous into safety.") Edited by Ding Shan)