Longitudinal and temporal water temperature patterns in the Yangtze River and its influence on spawning of the Chinese sturgeon (Acipenser sinensis Gray 1835)

摘要: In this study, water temperature longitudinal and temporal patterns were investigated in four locations of the Yangtze River to identify their influence on spawning Chinese sturgeon (Acipenser sinensis Gray 1835). The results showed that, historically (1960–1980), locations, Pingshan (PS, 2,687 river kilometres [rkm]), Yichang (YC, 1,640 rkm), Chenglingji (CLJ, 1,265 rkm), Hukou (HK, 805 rkm), all had similar average annual temperatures (around 18.0 °C) but very different amplitudes: upper two PS (11.4–23.2 °C) YC (9.1–25.9 °C), relatively stable smaller amplitude than lower ones, CLJ (6.0–30.0 °C) HK (5.9–30.8 °C). On basis physiological effects for sturgeon, we defined three ranges: stressing (>23 °C), holding (23–20 °C), (20–16 °C). We found that with successful (PS YC) short or no period long periods. Currently (2013–2016), impoundment Three Gorges Reservoir increases time decreasing 20 °C at current ground (YC) autumn, which periods, has significant negative impact sturgeon. Nonetheless, considering high duration periods HK, propose is still most suitable location