Qiuwen Chen

Development of Fish Passage in China

China began to develop fish passage at hydroelectric dams in the 1960s, but few were implemented until the 2000s, when a federal law was passed in 2002 that required fish passage at new hydroelectric dams that block fish migrations. Because of this regulation, in the past 10 years, about 40 fish passage facilities have been or are being built. Even though fish scientists and hydraulic engineers are enthusiastic to develop fish passage, progress is limited mainly because of (1) the lack of an accepted and enforced process to plan, design, and evaluate fish passage; (2) the lack of knowledge on migratory fish life history movement, behavior, and swimming ability; and (3) the failure of fish biologists and engineers to work together as a fish passage team. Future development should focus on the following: educating agency staff, fish biologists, and the public on the importance of river connectivity and migratory fish conservation using fishways; improving regulations; and setting national standards that req...

Ontogenetic changes in schooling behaviour during larval and early juvenile stages of Chinese sucker(Myxocryprinus asiaticus)

Juveniles Chinese sucker(Myxocryprinus asiaticus)obtains schooling swimming behavior.However,it is unclear when and why they form schooling behavior.We researched the mechanism of schooling formation related to hydraulics.We analyzed swimming behavior of Chinese sucker that ranged from 5 to 39 days post hatching(dph)at 20 ℃ water temperature by video record.Swimming speed,nearest neighbor distance(DNN),separation swimming index(ISS)and the Reynolds number based on total length(RL)were calculated.ISS decreased significantly with age,significantly lower than random distribution value at 19 dph(1.77 cm in total length,TL)and became stable at the lowest value at 32 dph(2.40 cm,TL).DNN changed in a similar way to ISS.The variation of ISS and DNN illustrated the schooling behavior was formed at the 19 dph and became tight schooling at 32 dph.The total length increased with age at function y=1.260 33-0.015 58×x+0.003 15×x2-(4.849 78E-5)×x3.Swimming speed first increased and then decreased and finally became stable at 2.45+0.15 TL/S after 19 dph.RL increased with age at function y=-607.891 61+156.809 12×x-4.212 9×x2+0.037 9×x3,RL exceeded 200 at 5-6 dph,equaled 1 111 at 19 dph.Analyses showed that the RL did not explain the schooling behavior of Chinese sucker,and schooling behavior was more likely related to the swimming behavior,as swimming changed from intermittent sprinting to continuous cruising when schooling was formed.