The latest communiqué on the special investigation of aquatic biological resources of the Yangtze River has been released.
According to the website of the Ministry of Agriculture and Rural Affairs, the "Communiqué on the Status of Aquatic Biological Resources and Habitat in the Yangtze River Basin (2022)" was recently released. The Communiqué reflects the status of aquatic biological resources, key protected species, alien species, habitats, aquatic biological integrity indices and other important tributaries of the Dadu River, Minjiang, Tuojiang, Chishui River, Jialing River, Wujiang River and Hanjiang River in 2022.
Yichang, Hubei, Chinese sturgeon in the waters of Gezhouba in the Yangtze River.
According to the Communiqué, the value of the aquatic biological integrity index in the Yangtze River Basin is still at a low level overall. The Aquatic Integrity Index of the main stream of the Yangtze River, Dongting Lake and Poyang Lake was rated as "poor", unchanged from 2021, but improved by two levels compared to 2018. The evaluation grade of the Chishui River Aquatic Biological Integrity Index was "good", the Tuojiang, Jialing, Wujiang and Hanjiang rivers were "poor", and the Dadu River and Minjiang River were "poor". The conservation situation of key species in the Yangtze River Basin is still grim, and it is estimated that there are only 13 broodstock (sexually mature and can participate in reproduction) under Gezhouba, and no natural reproduction has been monitored. 438 Yangtze sturgeon were detected, all of which were artificially released individuals, and there were no naturally breeding individuals.
In addition, 23 species of alien fish were monitored in key waters of the Yangtze River Basin, and compared with 2021, new species such as Larsnier, Brachylid giant fat carp, cloud-spotted catfish, Galileo tilapia, green sunfish and rainbow trout were newly detected, indicating an increase in alien species and a certain risk of invasion.
Yichang, Hubei, Chinese sturgeon in the waters of Gezhouba in the Yangtze River.
According to the communiqué, with the steady implementation of the ten-year fishing ban on the Yangtze River, the amount of aquatic biological resources in the Yangtze River Basin has shown a recovery trend, and the level of aquatic biodiversity has improved. In 2022, 193 species of indigenous fish were monitored in key waters of the Yangtze River Basin, an increase of 25 species over 2020 (the same monitoring point). The unit catch monitored by scientific research on the main stream of the Yangtze River increased by 20.0% over the previous year. The natural population of the Yangtze finless porpoise is about 1,249, an increase of 23.4% compared with 2017, with an average annual growth rate of 4.3%. The four large fish, knife fish and other resources have recovered significantly, and the knife fish can migrate to Dongting Lake, the farthest water in history, and the carp that has not been monitored for many years appears in the middle and lower reaches of the Yangtze River and many waters of the main tributaries of the Yangtze River and Tongjiang Lake. In terms of habitat, the habitat status of aquatic organisms in the Yangtze River Basin is generally stable. The water quality of the main stream of the Yangtze River is excellent, and the national control section of the main stream has reached Class II. water quality for three consecutive years. Compared with 2021, the length of the river involved in the channel improvement project under construction of the main stream of the Yangtze River has also decreased slightly.
The Ministry of Agriculture and Rural Affairs said that the next step will be to work with relevant departments, local governments and scientific research units to continue to consolidate the 10-year fishing ban on the Yangtze River, and further strengthen protection and restoration measures, optimize investigation, monitoring and evaluation, and better serve and support the high-quality development of the Yangtze River Economic Belt in view of the situation and problems reflected in the communiqué.
According to the Communiqué on Aquatic Biological Resources and Habitat Status in the Yangtze River Basin (2021), the breeding population size of Chinese sturgeon was about 15 in the Yichang section under Gezhouba, 1 Chinese sturgeon sub-adult in the middle Yichang section, and no wild Chinese sturgeon juveniles were detected in the main stream of the Yangtze River. A total of 639 Yangtze sturgeon were detected in the Yangtze River basin, and the natural spawning behavior of Chinese sturgeon and Yangtze sturgeon was not monitored.
According to the Communiqué on the Status of Aquatic Biological Resources and Habitat in the Yangtze River Basin (2020), no natural spawning activities of Chinese sturgeon were monitored in the Yichang River section under Gezhouba. From 2013 to 2020, only in 2016 was the natural breeding activity of Chinese sturgeon monitored in this section of the river. Hydroacoustic surveys showed that the estimated breeding population of Chinese sturgeon in the Yichang River section under Gezhouba was 13. No juvenile Chinese sturgeon were detected in the middle and lower reaches of the Yangtze River or at the mouth of the Yangtze River, and 3 Chinese sturgeon subadults were detected at the mouth of the Yangtze River.
The Communiqué on the Status of Aquatic Biological Resources and Habitat in the Yangtze River Basin (2019) also stated that the natural spawning activities of Chinese sturgeon were not monitored in the Yichang River section under Gezhouba. Hydroacoustic surveys showed that the estimated number of Chinese sturgeon breeding population in this section of the river was 16. No juvenile Chinese sturgeon were detected in the middle and lower reaches of the Yangtze River or the mouth of the Yangtze River, and 49 Chinese sturgeon subadults were caught by mistake in the middle and lower reaches of the Yangtze River.