• Title/Summary/Keyword: Critical swimming velocity

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Determination of Critical Swimming Velocity for Crucian Carp for Fishway Design (어도 설계를 위한 붕어의 한계유영유속 결정 연구)

  • Se Won Lee
    • Ecology and Resilient Infrastructure
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    • v.10 no.4
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    • pp.258-265
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    • 2023
  • Fishways installed in Korea usually generate high-velocity flows and low water depth that impede fish movement, despite the fact that most fish are migratory or move to survive. Moreover, domestic design standards for fishways fail to consider the swimming ability of various fish species that live in rivers. Therefore, it is necessary to establish design standards for fishways to function properly, which requires research on the swimming performance of domestic migratory fish and the hydraulic characteristics of fishways. Accordingly, in this research, the swimming performance of fish was objectively analyzed by applying the incremental velocity and fixed velocity methods to carp, respectively, and the critical swimming velocity was presented. As the result, it was appropriate to set the critical swimming velocity to 0.7 m/s - 0.8 m/s for incremental velocity and 0.8 m/s for fixed velocity. Comprehensively analyzing the two experimental methods, the critical swimming velocity for designing the fishway for carp can be determined to be about 0.8 m/s. In the future, it will be necessary to analyze the swimming performance of various migratory fish and prepare fishway design standards for each species.

An Experimental Study on the Swimming Performance of Pale Chub(Zacco platypus) (피라미의 유영특성에 관한 실험적 연구)

  • Park, Seong-Yong;Kim, Seo-Jun;Lee, Seung-Hwi;Yoon, Byung-Man
    • Journal of Korea Water Resources Association
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    • v.41 no.4
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    • pp.423-432
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    • 2008
  • The local migration or movement behavior of fishes in streams are related to feeding, spawning, growing, dispersing, and refuging. The pale chub (Zacco platypus) is a dominant species that migrates locally and inhabits in river and stream in Korea. However, dams, weirs, culverts and other regulatory structures are physical barriers that limit fish movement and fragment habits and populations. If main stream and off-channel habitats are connected with culverts, they would restrict the small fish as pale chub movement due to the high flow velocities and low depths. But in Korea, there is no experimental study to evaluate the swimming performance of species in Korea. Therefore, it is difficult to proposed that design guidelines for pass fishes through culverts. The purpose of this experimental study is to evaluate the swimming performance of pale chubs. A series of swimming performance test has been used in both of the fixed velocity and the incremental velocity methods in an experimental flume. As a result, the critical swimming speed for pale chub(body length 8.9 cm) was found to be about 0.7 m/s. Therefore, the flow velocity for culvert design in the low flow condition should not be exceed the its swimming ability, especially 0.7 m/s for pale chubs(body length 8.9 cm). And the minimum depth for culvert design in the low flow condition should not be lower than the fish body height add a dorsal fin height.