金沙江下游圆口铜鱼生境适宜度曲线的构建

The formation of habitat suitability curves for Coreius guichenoti (Sauvage & Dabry de Thiersant,1874) of the lower Jinsha River

金沙江下游的水电梯级开发对长江上游重要特有鱼类圆口铜鱼的自然栖息生境造成了严重影响,开展生境恢复是保护其资源的重要手段之一。为获得圆口铜鱼的生境恢复目标,构建圆口铜鱼不同生活史阶段对关键环境因子的适宜度曲线具有重要意义。基于2012—2014年5—7月在金沙江下游宜宾、巧家和皎平渡断面的早期资源采样结果,以及2016年5—7月在金沙江下游攀枝花至金阳干流江段的野外个体采集和栖息地生境调查结构,分别构建了圆口铜鱼亲鱼和幼鱼群体对水温、水深、流速和底质类型的适宜度曲线,结果显示:圆口铜鱼亲鱼的最适繁殖水温范围为20—25.2℃,最适栖息水深为1.2—11.5 m,最适栖息流速为0.2—1.3 m/s,最适栖息底质类型为小型卵石、大型卵石和巨石,而圆口铜鱼幼鱼栖息的最适水温范围为19.8—25.4℃,最适水深为0.4—3.95 m,最适流速为0.1—0.7 m/s,最适底质类型为细小砾石、中型砾石、大型砾石、小型卵石和大型卵石。上述结果不仅能够为水电工程影响下关键鱼类生境质量评价提供基础数据支撑,而且能够为鱼类生境保护和修复政策制定提供科学依据。

Coreius guichenoti is an important endemic fish species in the lower reaches of the Jinsha River.Due to the cascade hydropower development,its nature habitats suffered serious impacts.It is urgent to protect its habitat and restore its population resources.In order to obtain habitat restoration goals,obtaining the key environmental factors and forming the suitability curves for the different life history stages of C.guichenoti are very important.In this study,we sampled the eggs in the Yibin,Qiaojia and Jiaopingdu sections from May to July in2012-2014,and collected filed individual and surveyed the habitat in the lower reaches of the Jinsha River(from Panzhihua to Jinyang)during the period from May to July in2016.Based on these data,we set up the suitability curves of water temperature,water depth,velocity and substratum type for the parent individuals of C.guichenoti and its juveniles.The results showed that for adults(1)the range of the optimum breeding water temperature was20-25.2℃,(2)the range of the most suitable habitat depth was1.2-11.5m,(3)the range of the most suitable velocity was0.2-1.3m·s-1,and(4)the most suitable substratum types were small stones,large stones and boulders.For thejuveniles(1)the optimum temperature range was19.8-25.4℃,(2)the optimum depth range was0.4-3.95m,(3)the optimal velocity range was0.1-0.7m·s-1,and(4)the most suitable types of substratum were fine gravel,medium gravel,large gravel,small stones and large stones.This study not only can provide basic data for the habitat quality assessment of the critical fish species under the influences of hydropower projects,but also can provide a scientific basis for the policy formulation of fish habitat protection and restoration.