• Journal of Environmental Impact Assessment
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• v.26 no.3
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• pp.181-194
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• 2017

While over 90 percent of fishways are made up with concrete material, nature-like fishways are started to be established as a form of small stream using natural materials. Recently, the central government in collaboration with a university has proposed a 'Standard Model of Nature-like Fishway' with a purpose to provide as a national design standard of nature-like fishway. This study aims to criticize the proposed design model of nature-like fishway and to propose improvements by examining other international cases. As a result, we found problems and limitations of the proposed design model due to the lack of research and experience about making nature-like fishway in Korea. Especially, for designing bypass nature-like fishway we found the lack of studies about structure management strategies, establishment of rocks or pebbles inside the stream, and natural materials. In this sense, more studies about nature-like fishway design adaptable to our environment need to be conducted. In addition, since the proposed design standard for nature-like fishway has been created based on the limited examination of existing domestic cases, it is desirable to improve the design standard on the basis of hydrological and biological research so that they could be adapted effectively to regional and local contexts.

• Journal of Ecology and Environment
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• v.39 no.1
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• pp.43-49
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• 2016

Fishways are constructed to provide longitudinal connectivity of streams or rivers where their flow has been altered by in-stream structures such as dams or weirs. Nature-like fishways have an additional function of providing fish habitats. In the study, we estimated the role of a nature-like fishway (length: 700 m, slope: 1/100) for fish habitat by using two dominant species in the Sangju Weir, Nakdong River, to calculate the optimal ecological flow rate using Physical HABitat SIMulation (PHABSIM). To identify the dominant species that used the fishway, we conducted trap monitoring from August to November 2012 at the fishway exit. The dominant species were Zacco platypus and Opsariichthys uncirostric amurensis with a relative abundance of 62.1% and 35.9%, respectively. Optimal habitat suitability indices (HSIs) for Z. platypus and O. u. amurensis were calculated as 0.6-0.8 m/s (water velocity) and 0.2-0.4 m (water depth), and 0.5-0.7 m/s (water velocity) and 0.1-0.3 m (water depth), respectively. The optimal ecological flow rates (OEFs) for Z. platypus and O. u. amurensis were 1.6 and 1.7 cubic meter per second (CMS), respectively. The results of the study can be used in a management plan to increase the habitat function of nature-like fishways in the Sangju Weir. This methodology can be utilized as an appropriate tool that can determine the habitat function of all nature-like fishways.

• Korean Journal of Ecology and Environment
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• v.48 no.4
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• pp.212-218
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• 2015

In South Korea, various nature-like fishways recently been installed for use by a wide variety of fish species. However, limited attempts have been made to monitor the fish utilization. The present study was conducted to ascertain the frequencies and patterns of utilization of the fishway installed at Beakjae Weir. We collected fish species that use the fishway by installing a fyke net at the exit of the fishway at least once a month from April 2013 to October 2013. Additionally, in order to identify all fish species that can potentially use the fishway, we investigated the fish fauna downstream to Beakjae Weir (mainstream of the Geum River). We found that 10 species belonging to 2 families used the fishway; this accounted for 64% of the total species inhabiting the mainstream. The species that used the fishway most frequently were Microphysogobio jeoni, followed by Squaliobarbus curriculus and Opsariichthys uncirostris amurensis. The highest number of fish using the fishway was observed in August, which was positively correlated with the water temperature (Spearman rank correlation, $r_s$=0.743, P=0.035). The sizes of the fish using the fishway varied widely, with the total body length ranging from 39 mm to 550 mm. Analysis of the time-dependent utilization frequency revealed that most fish used the fishway during the night (20:00~08:00). Compared to other fishways installed along the Geum River, the fishway installed at Beakjae Weir was used by fewer species and fish. This may be attributed to the structural inadequacy of the fishway, thereby resulting in a low attraction efficiency. Therefore, measures should be adopted to enhance the fishway attraction and passage efficiency. The results of this study can be used to ensure efficient operation and management of the Beakjae Weir fishway as well as serve as basic data for developing and building nature-like fishways tailored to Korean situations.