金沙江乌东德水电站生态调度目标鱼类筛选研究

Target Fish Screening for the Ecological Operation of Wudongde Hydropower Station on Jinsha River

对乌东德坝下江段鱼类生态调度需求次序进行定量研究,为生态调度目标物种的选择以及生态调度方案制定提供决策依据。采用2008年6月和11月、2009年4月、2011年6月、2012年4-5月、2013年4-5月的金沙江干支流渔获物调查结果,以及2016-2019年金沙江下游流域水生生态监测结果,考虑不同鱼类繁殖对生态水文过程的需求以及数据可得性,构建包含物种濒危系数、遗传价值系数和物种价值系数在内的评价体系,对金沙江乌东德坝址至白鹤滩坝址之间分布的53种土著鱼类进行生态调度需求次序的定量研究。结果表明,处于生态调度需求1级的鱼类有4种,为圆口铜鱼、长鳍吻鮈、中华金沙鳅和齐口裂腹鱼,这些鱼类均属长江上游特有鱼类,也是受水电开发影响较为显著的种类;处于生态调度需求2级的鱼类有14种,包括长江上游特有鱼类11种,这些鱼类产卵繁殖对流水生境均有一定需求;处于生态调度需求3级的鱼类有28种,这些鱼类以广适型种类为主,对水流条件的要求不高;处于生态调度需求4级的鱼类有7种,多为常见的小型鱼类,其产卵繁殖对生境要求不高。评价结果基本反映了乌东德坝下江段鱼类对生态调度的实际需求,考虑到产漂流性卵鱼类和产粘沉性卵鱼类繁殖需求的差异,综合确定圆口铜鱼和齐口裂腹鱼为乌东德水电站生态调度的主要目标鱼类,长鳍吻鮈、中华金沙鳅等作为兼顾目标鱼类。

Ecological regulation is an effective measure for mitigating the adverse impacts of hydropower projects on fish. Determining the target fish to be managed is the basis for formulating an ecological regulation scheme. Based on field investigation and review of relevant literature, the conservation priority of 53indigenous fish species distributed between Wudongde dam and Baihetan dam on the Jinsha River was quantitatively analyzed by developing an evaluation index system that included an endangerment coefficient, a genetic value coefficient and a species value coefficient. The aim was to provide a means for determining target fish species for ecological regulation to support development of an ecological regulation scheme. The data for this study was obtained from investigating results of fish catches on the mainstem of Jinsha River(June and November of 2008, April of 2009, June of 2011, and April and May of 2012 and 2013), as well as monitoring results from 5 transects(May to July and October to December, 2016-2019). A total of 55 fish species from 42 genera, 10 families and 3 orders were recorded in the study area, including 53 native species(15 endemic to the upper Yangtze River) and 2 invasive species. According to the evaluation index system,there are 4 species at the first level of ecological regulation demand, including Coreius guichenoti, Rhinogobio ventralis, jinshaia sinensis and Schizothorax prenanti. These species are all endemic to the upper Yangtze River, with rich resources and high occurrence rates in the study river section, and all were significantly affected by changes in the runoff process caused by hydropower development. There are 14 fish species in the second level of ecological regulation demand, including 11 species endemic to the upper Yangtze River and require a flowing water habitat during the spawning and reproduction season. In the third level there are28 fish species that display wide habitat adaptability and tolerate different water flow conditions. In the fourth level there are 7 fish species, mostly common small-size fish with no special habitat requirements for spawning and reproduction. The evaluation results reflect the actual situation of fish species in the reach below Wudongde dam. After considering the differences in reproductive requirements of species with drifting and viscous eggs, our comprehensive determination of conservation priority indicates that C. guichenoti and S. prenanti are the primary target species for ecological regulation at Wudongde hydropower station, followed by R. ventralis and j. sinensis.