The effect of cascaded huge dams on the downstream movement of Coreius guichenoti (Sauvage & Dabry de Thiersant, 1874) in the upper Yangtze River

摘要: Huge dams (installed capacity > 100 MKW) are generally built on large rivers that display high biodiversity and include major migration routes for many diadromous potamodromous fish. As a result, these lead to severe ecological impacts receive more attention than smaller dams. Most previous work the impact of huge fish downstream movement has focused single dam reservoir, so little is known about effect cascaded reservoirs movement. During period 2012–2014, two (the Xiangjiaba Xiluodu) were constructed upper Yangtze River reservoir impoundments began, respectively in October 2012 May 2013. These hydroelectric projects could have adverse an important species, Coreius guichenoti. To study sequential passive active C. guichenoti, eggs larvae collected Yibin section during 2012–2014 monthly at site Hejiang from June July 2014. Our results showed that, compared one dam, exert serious obstruct eggs, young (particularly yearlings two-year-olds) Individual guichenoti able pass with relative ease through but passing both was very difficult. allow access spawning grounds upstream, passage should be Xiluodu dam. However, due hydropower development whole basin, captive breeding maintaining least 60 km riverine habitat upstream ground cost-effective approach populations Upper River.