Effects of artificial riverbanks on distribution of the Yangtze finless porpoise in the Anqing section of the Yangtze River main stem

2018 ◽  
Vol 38 (3) ◽  
Author(s):  
陈敏敏 CHEN Minmin ◽  
刘志刚 LIU Zhigang ◽  
黄杰 HUANG Jie ◽  
连玉喜 LIAN Yuxi ◽  
杨晓鸽 YANG Xiaoge ◽  
...  
2008 ◽  
Vol 141 (12) ◽  
pp. 3006-3018 ◽  
Author(s):  
Xiujiang Zhao ◽  
Jay Barlow ◽  
Barbara L. Taylor ◽  
Robert L. Pitman ◽  
Kexiong Wang ◽  
...  

PLoS ONE ◽  
2019 ◽  
Vol 14 (8) ◽  
pp. e0221120
Author(s):  
Yongkai Tang ◽  
Yunsheng Wu ◽  
Kai Liu ◽  
Jianlin Li ◽  
Hongxia Li ◽  
...  

<em>Abstract</em>.—Two species of cetaceans are endemic to the Yangtze River, the baiji or Yangtze River dolphin <em>Lipotes vexillifer </em>and the Yangtze finless porpoise <em>Neophocaena asiaeorientalis asiaeorientalis</em>. Over the past several decades, both species have suffered dramatic declines in abundance and concomitant reductions in the extent of their geographic ranges. In 2006, the baiji was presumed to be extinct when an extensive survey of the Yangtze River failed to find any evidence of its continued existence. Data from that same survey further indicated that the population size of the Yangtze finless porpoises had decreased from 2,700 in 1991 to approximately 1,800 individuals by 2006. Results of a more recent population survey of the Yangtze River conducted in 2012 revealed that this rapid decline has continued, with only approximately 1,000 Yangtze finless porpoises remaining across their former range. The population viability of both species is threatened primarily by overfishing and illegal fishing of their prey, heavy boating traffic, sand dredging, construction projects in or near the water, and pollution throughout the Yangtze River ecosystem. In an attempt to protect these species, several conservation strategies, including in situ conservation (i.e., on-site conservation), ex situ conservation (i.e., off-site conservation), and captive breeding programs have been implemented. In this review, we examine the effectiveness of these conservation strategies over the past three decades and synthesize these findings to make recommendations for the future protection of the Yangtze finless porpoise.


<em>Abstract</em>.—The Yangtze River is the largest river in China, with a drainage area encompassing a land area of 1.8 × 10<sup>6</sup> km<sup>2</sup>. The river main stem flows approximately 6,300 km from west to east through 11 provinces, eventually emptying into the East China Sea. The total basin area of the Yangtze River provides more than 40% of China’s gross domestic product, sustains nearly 500 million people, and plays a vital role in the overall socioeconomic development of China. Because of longitudinal differences in geomorphology, the Yangtze River is often divided into upper, middle, and lower reaches for the purposes of study and description. In general, the Yangtze River basin has a warm climate and abundant rainfall. The subtropical monsoon climate accounts for 70–80% of its annual rainfall, which produces predictable annual flood events during summers of each year. The Yangtze River ecosystem also has diverse aquatic habitats that support high biodiversity. The Yangtze River main stem contains more than 3,000 tributaries and approximately 4,000 lakes that provide important habitats for thousands of aquatic species, which include 378 fish species. Yet, the ecological communities of the Yangtze River have been dramatically impacted in recent decades due to high degrees of anthropogenic activities associated with the economic development of China. Significant biodiversity declines occurring throughout the basin have been largely attributed to hydropower dam construction, overexploitation of major fisheries, water pollution, and habitat fragmentation. In addition, widespread disconnection of the Yangtze River main stem from its floodplain lakes, lake reclamation projects, invasions by exotic species, and other serious ecological problems threaten the survival of the remaining aquatic resources in the basin. To offset the adverse effects of these threats, a number of nature reserves have been established. Additionally, protection and restoration measures, including spring fishing closures, artificial population enhancement strategies, and complete habitat restoration projects, have been implemented throughout the basin. Although these projects have yielded some encouraging results to date, they are still considered inadequate. It is recommended that an integrated strategy that includes cross-functional communication mechanisms, more comprehensive monitoring, ecological rehabilitation, and government legislation is still needed. This will insure that utilization and development in the Yangtze River ecosystem are sustainable and balanced with conservation and ecological needs.


2016 ◽  
Vol 36 (7) ◽  
Author(s):  
张晓可 ZHANG Xiaoke ◽  
于道平 YU Daoping ◽  
王慧丽 WANG Huili ◽  
万安 WAN An ◽  
蒋泽球 JIANG Zeqiu ◽  
...  

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8415
Author(s):  
Huaxing Zhou ◽  
Yuting Hu ◽  
He Jiang ◽  
Guoqing Duan ◽  
Jun Ling ◽  
...  

The swamp eel (Monopterus albus) is a typical sex reversal fish with high economic value. Several phylogeographic studies have been performed using various markers but comparative research between mitochondrial and nuclear markers is rare. Here, a fine-scale study was performed across six sites along the Yangtze River including three sites on the main stem and three sites from tributaries. A total of 180 swamp eel individuals were collected. Genetic structure and demographic history were explored using data from two mitochondrial genes and eight microsatellite loci. The results revealed the samples from tributary sites formed three separate clades which contained site-specific lineages. Geographic isolation and the habitat patchiness caused by seasonal cutoff were inferred to be the reasons for this differentiation. Strong gene flow was detected among the sites along the main stem. Rapid flow of the river main stem may provide the dynamic for the migration of swamp eel. Interestingly, the comparative analyses between the two marker types was discordant. Mitochondrial results suggested samples from three tributary sites were highly differentiated. However, microsatellite analyses indicated the tributary samples were moderately differentiated. We conclude this discordance is mainly caused by the unique life history of sex reversal fish. Our study provides novel insights regarding the population genetics of sex reversal fish.


Sign in / Sign up

Export Citation Format

Share Document