A Yangtze finless porpoises was captured during the scientific survey based on capture & release operations of Yangtze finless porpoises.

With the aim of probing more deeply into the population status of Yangtze finless porpoises living in Poyang Lake (the largest freshwater lake in China which is located in Jiangxi province), a large-scale scientific survey based on capture & release operations of Yangtze finless porpoises was carried out in Duchang region during February 18th and 25th.

The number of captured Yangtze finless porpoises for this year’s survey is 45, which exceeds the total captured number of the past two years. No harm and danger have been caused to either the porpoises or the participants during the whole survey. Researchers from Institute of Hydrobiology (IHB), Chinese Academy of Sciences performed morphological measurements, physical examination, PIT label embedding, and biological sampling on the captured Yangtze finless porpoises. They also treated wounds for the injured Yangtze finless porpoises and released them back to the Poyang Lake. The physical appearance and fatness of the captured Yangtze finless porpoises are far better than the individuals captured in the past two years. More female finless porpoises were captured than males. What is more pleasing is that among the captured 17 mature female finless porpoises, 11 are pregnant. The pregnancy rate reaches 64.7%.  

The current survey indicates that the number and health status of Yangtze finless porpoises are directly  influenced by the water level and fish resources of Poyang Lake and strongly affected by fishing activities. It is hoped that, if illegal fishing activities can be prohibited and more concern can be given to the protection of fish resources in Poyang Lake, the population of Yangtze finless porpoise in this lake may gradually recovers or even grows larger.

Researchers performed physical examination on a captured Yangtze finless porpoise.

On Feb 26, one day after the survey was finished, the investigators sent out questionnaires and introduced the living status, population size and distribution of Yangtze finless porpoises to the local fishermen, letting them be aware of the dangers that the porpoises are now facing. They also appealed the fishermen to create eco-harmony fishery in Poyang Lake where the Yangtze finless porpoises can also be conserved. So far, the three-years scientific survey on Yangtze finless porpoises in Poyang Lake, undertaken by IHB, has been successfully accomplished.  

Poyang Lake is one of the most important habitats for the Yangtze finless porpoise .There are about 450 Yangtze finless porpoises living in the lake, which is the most intensive and largest natural population of Yangtze finless porpoise. Thus, the conservation of this population is vital to the existence of the Yangtze finless porpoise.  

Researchers from IHB, together with six technicians from Hubei Tian-e-zhou Baiji National Reserve, Hubei Xin-luo Baiji National Reserve and Pearl River Estuary Chinese White Dolphin National Nature Reserve, undertook this survey with the assistance of Duchang Fishery Administrative Bureau. In addition, 36 fishermen from both Hubei Province and Jiangxi Province participated in this survey.