放归长江鲟亲鲟的栖息地选择及关键栖息地适宜性评价

长江鲟为极度濒危物种，规模化增殖放流是当前恢复其自然种群的重要手段。基于近3年对放流长江鲟亲鲟的连续监测结果，发现其历史主要分布区内关键栖息地的功能性依然存在。但随着向家坝等长江上游梯级水坝的蓄水和运行，长江鲟关键栖息地将面临功能退化和适合度下降的风险，因此，长江鲟亲鲟在野外放归后的栖息地选择及其对关键栖息地的适宜性状况是目前亟需了解和研究的问题。本研究拟通过超声波生物遥测技术，对放归野外的长江鲟亲鲟展开周年的连续追踪监测，掌握其野外放归后的时空分布规律；利用科学回声探测仪、多普勒剖面流速仪等声学设备测量其关键栖息地的水深、流速等非生物环境因子，阐明放归亲鲟对栖息地非生物环境的具体需求特征。基于最大熵模型，结合放归亲鲟的空间分布和非生物环境因子，定量地评估其对关键栖息地的适宜性状况。研究结果将为后续该物种栖息地修复提供科学依据，同时也为长江鲟自然种群重建工作提供理论依据和指导建议。

Yangtze sturgeon (Acipenser dabryanus) is a critically endangered species. Large scale stock enhancement is currently becoming a major means to restore its nature population and conservation. According to the continuous monitoring results of the released adult hatchery reared Yangtze sturgeons in the past three years, it was found that the function of the key habitat in the main historical distribution areas still exists. However, with the impoundment and operation of Xiangjiaba Dam and other cascade dams in the upper Yangtze River, the key habitat of Yangtze sturgeon will be at the risk of functional degradation and fitness decline. Therefore, habitat selection and key habitat suitability of the released adult hatchery reared Yangtze sturgeons are urgent problems to be studied. This project intends to continuously monitor the released adult hatchery reared Yangtze sturgeons through ultrasound biotelemetry, and in order to know the spatiotemporal distribution characteristics of the released sturgeons. Furthermore, abiotic environment factors such as water depth and velocity of the key habitat will be measured through acoustic equipment like scientific echo-sounder and acoustic doppler current profiler, which will be used to clarify the specific needs of the released adult sturgeons for the abiotic habitat environment. Combined with the spatial distribution and abiotic environment factors, habitat suitability of the key habitat will be quantitatively evaluated based on the maximum entropy model. Results of this project will provide a scientific and theoretical basis for the subsequent wild populations reconstruction and habitat restoration of this species.