Zhang Hui, Kang Myounghee, Wu Jinming, Wang Chengyou, Li Junyi, Du Hao, Yang Haile, Wei Qiwei
Key Laboratory of Freshwater Biodiversity Conservation, Ministry of Agriculture and Rural Affairs of P. R. China, Wuhan 430223, Hubei Province, China.
Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan 430223, Hubei Province, China.
Animals (Basel). 2019 Aug 20;9(8):583. doi: 10.3390/ani9080583.
The Yangtze River has the third greatest water flow and is one of the most human-influenced rivers in the world. Since 1950, this river system has experienced drastic human interventions, leading to various environmental changes, including water temperature. In this study, based on observations during the past sixty years, we found that the seasonal temperature regime has been altered, both temporally (1-5 °C variation) and spatially (>626 km distance). Temperature shifts not only delay the timing of fish spawning directly, but also lead to degeneration in gonad development. Temperature regime alterations have delayed the suitable spawning temperature window by approximately 29 days over a decade (2003-2016). It confirmed that a period of lower temperature, higher cumulative temperature, and relatively higher temperature differences promoted the maturation of potential spawners based on the correlation analysis ( < 0.05). Also, thermal alterations were highly correlated with reservoir capacity upstream (R = 0.866). On-going cascade dam construction and global warming will lead to further temperature shifts. Currently, rigorous protection measures on the breeding population of the Chinese sturgeon and its critical habitats is urgently needed to prevent the crisis of the species extinction. Increasing river thermal shifts not only threaten the Chinese sturgeon but also affect the entire Yangtze aquatic ecosystem.
长江是世界上水流第三大的河流，也是受人类影响最为严重的河流之一。自1950年以来，该水系经历了剧烈的人类干预，导致了包括水温在内的各种环境变化。在本研究中，基于过去六十年的观测，我们发现季节性温度模式在时间（1 - 5°C变化）和空间（>626公里距离）上都发生了改变。温度变化不仅直接延迟了鱼类产卵的时间，还导致性腺发育退化。在十年间（2003 - 2016年），温度模式的改变使适宜的产卵温度窗口推迟了约29天。基于相关性分析（<0.05）证实，一段较低温度、较高累积温度和相对较高温差的时期促进了潜在产卵者的成熟。此外，热变化与上游水库容量高度相关（R = 0.866）。正在进行的梯级大坝建设和全球变暖将导致进一步的温度变化。目前，迫切需要对中华鲟繁殖种群及其关键栖息地采取严格的保护措施，以防止该物种灭绝危机。河流热变化的加剧不仅威胁中华鲟，还影响整个长江水生生态系统。
