西藏水生生物资源与环境本底状况调查 (2017—2021)

Status of aquatic organisms resources and their environments in Xizang (2017—2021)

摘要:

目的 全面了解西藏水生生物资源和生态环境本底状况。方法 中国水产科学研究院 (长江水产研究所，黑龙江水产研究所，资源环境研究中心)、华中农业大学、中国科学院水生生物研究所和西藏农牧科学院水产科学研究所联合对西藏雅鲁藏布江、怒江、澜沧江、巴松错、哲古错、错那、错鄂 (三江四湖)的鱼类种类组成、鱼类资源量、渔业生态环境等开展了系统调查。结果 ①2017—2021年西藏三江四湖采集到鱼类53种，隶属于2目5科24属，其中土著鱼45种，外来鱼6种，杂交种鱼2种；②基于数量和生物量，雅鲁藏布江上游鱼类优势种包括拉萨裸裂尻鱼、双须叶须鱼、异齿裂腹鱼和尖裸鲤，中游鱼类优势种包括异齿裂腹鱼、巨须裂腹鱼、拉萨裸裂尻鱼、拉萨裂腹鱼，加查至桑日江段国家二级保护动物尖裸鲤和黑斑原鮡的重量占比均显著下降，下游鱼类优势种包括弧唇裂腹鱼、西藏墨头鱼、黄斑熠鮡、墨脱裂腹鱼、平鳍裸吻鱼，怒江鱼类优势种包括裸腹叶须鱼、热裸裂尻鱼、怒江裂腹鱼，澜沧江鱼类优势种主要为光唇裂腹鱼和澜沧裂腹鱼，巴松错鱼类优势种包括异齿裂腹鱼和巨须裂腹鱼，哲古错鱼类优势种包括异尾高原鳅、高原裸鲤和拉萨裸裂尻鱼，错那和错鄂鱼类优势种均为热裸裂尻鱼和异尾高原鳅；③外来物种主要分布在雅鲁藏布江中游；④西藏三江四湖水质基本符合渔业水质标准，雅鲁藏布江上游水域总氮和总磷的浓度均低于中游和下游。结论 2017—2021年西藏三江四湖调查到的土著鱼物种数 (45种)占西藏历史上土著鱼类物种数 (72种)的62.50%，异齿裂腹鱼和拉萨裸裂尻鱼是雅鲁藏布江上游和中游均有的优势种，雅鲁藏布江中游加查至桑日江段濒危物种尖裸鲤和黑斑原鮡的重量占比均显著下降；外来物种主要分布在雅鲁藏布江中游；三江四湖水质基本符合渔业水质标准。此次调查为西藏渔业资源与保护、特色资源可持续利用和生态环境可持续发展提供了重要的科技支撑。

Abstract:

Xizang serves as a crucial ecological and security barrier for China. Its fragile ecological environment is difficult to restore once destroyed. To implement the national policy prioritizing protection over development and to enhance the precision and pragmatism of agricultural support to Xizang, the Chinese Academy of Fisheries Sciences proposed a special initiative titled "Fishery source and environment survey of key waters in Xizang". This initiative was based on the unique characteristics of Xizang's fishery resources and environment. Field sampling and remote sensing monitoring were employed to comprehensively asscess the aquatic organisms and ecological environment in Xizang. The Yangtze River Fisheries Research Institute, Heilongjiang Fisheries Research Institute, Fishery Resource and Environment Research Center, Huazhong Agricultural University, Institute of Hydrobiology (Chinese Academy of Sciences), and Institute of Aquatic Science (Xizang Academy of Agriculture and Animal Husbandry Science) conducted surveys on fish species composition, abundance, and status of fisheries ecological environment in three rivers (Yarlung Zangbo River, Nujiang River, Lancang River) and four lakes (Basomtso Lake, Zhegu Lake, Lake Amdo Tsonak Co, and Co Ngoin Lake). From 2017 to 2021, 53 fish species were collected, belonging to 24 genera, 5 families, and 2 orders, including 45 native species, 6 non-native species, and 2 hybrids. Dominant species in the upper reaches of the Yarlung Zangbo River included Schizopygopsis younghusbandi, Ptychobarbus dipogon, Schizothorax oconnori, and Oxygymnocypris stewartii. In the middle reach, dominant species were S. oconnori, S. macropogon, S. younghusbandi, and S. waltoni. In the lower reach, dominant species were S. curvilabiatus, Garra kempi, Sisoridae sulcatus, S. molesworthi, Psilorhynchus homaloptera. In the Nujiang River, dominant species were Ptychobarbus kaznakovi, S. thermalis, S. nukiangensis. In the Lancang River, dominant species were S. lissolabiatus and S. lantsangensis. In the Basomtso Lake, dominant species were S. oconnori and S. macropogon. In the Zhegu Lake, dominant species were Triplophysa stewarti, Gymnocypris waddelli, S. younghusbandi. In the Lake Amdo Tsonak Co and Co Ngoin Lake, dominant species were S. thermalis and T. stewarti. Exotic species were primarily found in the middle reaches of the Yarlung Zangbo River. Water quality in the three rivers and four lakes generally met fishery standards, with lower concentrations of total nitrogen and total phosphorus in the upper reaches of the Yarlung Zangbo River compared to the middle and lower reaches. The survey results indicated that the number of native fish species collected (45 species) from 2017 to 2021 accounted for 62.50% of the total native fishes (72 species) recorded before 2017. The weight proportion of endangered O. stewartii and Glyptosternum maculatum have been decreased significantly in Sangri to Jiacha reach of middle Yarlung Zangbo River. Non-native species were predominantly found in the middle reach of the Yarlung Zangbo River. This survey provided critical scientific and technological support for the protection of Xizang's fishery resources, sustainable utilization of unique resources, and the sustainable development of ecological environment.