金沙江下游支流黑水河短须裂腹鱼栖息地的适宜性

Habitat suitability of Schizothorax wangchiachii in the Heishui River of the lower Jinsha River tributary,China

鱼类栖息地作为水生生态系统中的重要组成部分,对于维持水生生态系统、保护物种多样性和维护渔业可持续发展至关重要。为揭示金沙江下游支流黑水河短须裂腹鱼生境因子适宜性及栖息地分布规律,基于2018—2019年黑水河短须裂腹鱼渔获物数据及同步采集的16个环境因子数据,应用Spearman相关性单尾检验筛选栖息地指示因子,使用随机森林算法和加权平均法计算鱼类栖息地适宜性指数。结果表明:短须裂腹鱼关键生境因子最适栖息水温范围为16.3~16.8℃,水深范围为35~60 cm,海拔范围为637~816 m。从黑水河上游至下游短须裂腹鱼栖息地适宜性呈纵向增加趋势,栖息地质量低于良好标准的比例为70%,达到良好及非常好标准的比例仅为30%。短须裂腹鱼适宜栖息地主要分布在河道水文联通性高、水深较浅、饵料生物充足、流速较缓的自然流水河段,其栖息地适宜性表现出的明显空间分布差异可能是由小型水坝等人为干扰所导致。

As an important component of aquatic ecosystem,fish habitat is crucial for maintaining aquantic ecosystem,species diversity,and sustainable fisheries.To reveal the suitability of habitat factors and distribution patterns of Schizothorax wangchiachii in the Heishui River of the lower Jinsha River tributary,we selected the habitat indicators by the Spearman correlation single tail test,calculated the fish habitat suitability index by the random forest algorithm and weighted average method,based on the fish catch data and 16 related environmental factor data collected from 2018 to 2019.The results showed that the optimal range of water temperature,water depth,and altitude for S.wangchiachii was 16.3-16.8℃,35-60 cm,and 637-816 m,respectively.From the upper reaches to the lower reaches,the habitat suitability of S.wangchiachii showed a longitudinal increasing trend.The proportion of the habitat quality below the good standard was 70%,while the proportion reaching the good and very good stan-dards was only 30%.The habitat of S.wangchiachii was mainly distributed in the natural flowing river sections with high hydrological connectivity of the river course,shallow water depth,abundant bait organisms and slow flow rate.The obvious spatial differences of its habitat suitability might be caused by human disturbances such as the construction of small dams.