The scene of finless porpoises preying on swordfish in the Zhenjiang section of the Yangtze River has gone viral on the Internet. The simultaneous appearance of two rare animals reflects Jiangsu's persistent efforts to strengthen the protection and restoration of the Yangtze River ecological environment system in recent years, in particular significant results in biodiversity conservation.
Mr. Ma, a citizen of Zhenjiang, captured a wonderful scene of finless porpoises preying on swordfish by the Yangtze River. The finless porpoise and swordfish, two once endangered animals, are extremely rare in the Jiangsu section of the Yangtze River.
“The scene of finless porpoises eating swordfish is very rare, and it is the first time we have seen it in the protected area for so many years. This also indicates that the ecology of the Yangtze River has indeed improved,” Wang Zhaogen, Deputy Director of the Management Office of the Yangtze River Porpoise Provincial Nature Reserve in Zhenjiang, said.
The swordfish captured in this video is a representative migratory fish species in the Yangtze River. The period from May to July is the spawning season of swordfish with the number close to the peak. The Zhenjiang section of the Yangtze River is rich in bifurcated mudflat, plankton and other bait, making it a natural spawning ground of swordfish since ancient times.
Due to overfishing, swordfish was included in the International Union for Conservation of Nature Red List of Endangered Species in 2017. Starting from 2019, the fishing of swordfish in the Yangtze River has been completely banned. In July 2020, Jiangsu issued a ban on fishing in the Yangtze River Basin, with 7392 fishing boats and 14887 fishermen stopping fishing and settling ashore.
Jiangsu has simultaneously promoted a series of measures such as the renovation of the Yangtze River shoreline, water pollution prevention and control, and the construction of aquatic biological protection zones so that the Jiangsu section of the Yangtze River has witnessed a new stage in the water ecological protection.
The latest monitoring data from the Ministry of Agriculture and Rural Affairs shows that the amount of swordfish resources in the Yangtze River has doubled, enabling the endangered fish to migrate to Dongting Lake, the longest water area in history. In addition to swordfish, the latest environmental DNA monitoring also shows that more than 80 species of fish DNA signals have been detected in the Jiangsu section of the Yangtze River.
“After the ban on fishing in the Yangtze River, our monitoring found an increase in the number of species of fish surveyed, a gradual optimization of population structure, an increasing trend in individual and size, and an increasing number of large individuals, indicating that fish resources in the Yangtze River have significantly recovered after the ban,” said Gao Xin, Associate Researcher, Institute of Hydrobiology, Chinese Academy of Sciences.
The 432.5-kilometer section of the Yangtze River in Jiangsu connects 8 prefecture level cities, including Nanjing, Zhenjiang, Yangzhou, Taizhou, Changzhou, Wuxi, Suzhou, and Nantong. The 1169-kilometer coastline has nourished 1/6 of the province’s Yangtze River ecology.
The significant recovery of fish resources is a strong evidence of the continuous improvement of the ecological environment in the Yangtze River. More and more rare and endangered species have settled down in Jiangsu. In recent years, the national first-class protected animals Oriental white stork and Chinese merganser have frequently wintered in the mudflat along the Zhenjiang section of the Yangtze River. At the end of March, the black headed gull first appeared in large scale in Haimen section of the Yangtze River. On May 7, the critically endangered species Yellow breasted Bunting appeared in flocks in the Mazhou Island Ecological Wetland.
“We discovered a yellow breasted bunting around 6 o'clock in the morning through high-definition video surveillance installed on the island. Subsequently, we crouched there for nearly three hours and found over 30 yellow breasted bunting. This is also the largest population we have observed over the years,” said Wei Huiyu, staff member of the Yangtze River Biodiversity Conservation Scientific Observation and Research Station on Mazhou Island.
“According to the results of the biodiversity background survey, there are 6903 recorded species in the province, including 4124 species along the Yangtze River, accounting for nearly 60% of the total number in the province. Significant achievements have been made in biodiversity conservation,” said Zou Peng, Deputy Director of the Natural Department of the Jiangsu Provincial Department of Ecology and Environment.
