Research Paper

Enhancing invasive fish management with electrofishing: A case study from Longluan Lake, Taiwan

Cheng-Da Tsai, Shih-Hsiung Liang, Yuh-Wen Chiu, Cheng-Wei Tso, Da-Ji Huang

Published on: 28 January 2026

Page: 141 - 146

DOI: 10.6165/tai.2026.71.141

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    Abstract

    The spread of invasive alien species poses serious threats to freshwater ecosystems worldwide. Longluan Lake, a critical wetland in Kenting National Park, Taiwan, has been increasingly impacted by non-native fish species, including Channa striata, Oxyeleotris marmorata, and Oreochromis spp., which disrupt the native biodiversity and ecological balance. To enhance management efficiency, electrofishing was introduced in 2020 as a supplementary removal method alongside traditional techniques, including lure fishing, longline fishing, and fyke netting. Between 2020 and 2024, a total of 20 removal events were conducted, resulting in the capture of 18,677 individuals, of which 13,654 were non-native species. Electrofishing substantially increased capture rates of small-bodied and juvenile invasive fishes, with annual averages of C. striata and O. marmorata rising more than fourfold compared to pre-2020 levels. Notably, the mortality rates associated with electrofishing (9.2%) were also lower than those of fyke nets (32.8%), indicating reduced ecological disturbance to native species. Abundance Biomass Comparison (ABC) curve analyses revealed declining W values for key invasive species and partial recovery of native assemblages after the introduction of electrofishing. Our findings demonstrate that electrofishing, when integrated with conventional fishing methods, provides an effective and ecologically sustainable approach for managing invasive fish in wetland ecosystems.

    Keyword: electrofishing, invasive fish control, invasive species, Longluan Lake, Taiwan, wetland management

    Literature Cited

    Britton, J.R., Gozlan, R.E. 2013 How many founders for a biological invasion? Predicting introduction outcomes from propagule pressure. Ecology 94(11): 2558–2566.
    DOI: 10.1890/13-0527.1View Article Google Scholar

    Chopin, F.S., Arimoto, T. 1995 The condition of fish escaping from fishing gears—a review. Fish. Res. 21(3-4): 315–327.
    DOI: 10.1016/0165-7836(94)00301-CView Article Google Scholar

    Clarke, K., Gorley R. 2006 Primer 6.0 software. Primer-E Ltd., Plymouth.

    Cucherousset, J., Olden, J.D. 2011 Ecological impacts of non-native freshwater fishes. Fisheries 36(5): 215–230.
    DOI: 10.1080/03632415.2011.574578View Article Google Scholar

    Dalbey, S., McMahon, T., Fredenberg, W. 1996 Effect of electrofishing pulse shape and electrofishing-induced spinal injury on long-term growth and survival of wild rainbow trout. N. Am. J. Fish. Manage. 16(3): 560–569.
    DOI: 10.1577/1548-8675(1996)016<0560:EOEPSA>2.3.CO;2View Article Google Scholar

    Fischer, J.R., Quist, M.C. 2014 Characterizing lentic freshwater fish assemblages using multiple sampling methods. Environ. Monit. Assess. 186(7): 4461–4474.
    DOI: 10.1007/s10661-014-3782-xView Article Google Scholar

    FishBase 2024 Fishbase. Quantitative Aquatics, Incorporated https://fishbase.se/search.php.

    Huang, D.J., Liang, S.H., Chiu, Y.W., Chen, C.M. Hsien, K.J. 2018 Aquatic ecosystem monitoring program in longluan lake and nanren lake between 2017 to 2018 (486-106-04-493, in chinese). Ken-ting National Park, ROC.

    Huang, D.J., Liang, S.H., Chiu, Y.W., Chen C.M., Hsien, K.J. 2019 Aquatic ecosystem monitoring program in longluan lake and nanren lake between 2018 to 2019 (486-107-04-493, in chinese). Ken-ting National Park, ROC.

    Liang, S.H., Liang, B.A.W., Shieh, B.S. 2020 Determinants of establishment success: Comparing alien and native freshwater fishes in Taiwan. PLoS One 15(7): e0236427
    DOI: 10.1371/journal.pone.0236427View Article Google Scholar

    Liang, S.H., Tsai, C.D., Chiu,Y.W., Tso,C.W., Huang, Y.L., Huang, D.J. 2022 Optimal time of year and fishing methods for controlling exotic fishes in longluan lake, Taiwan. J. Environ. Biol. 43(4): 544–550.
    DOI: 10.22438/jeb/43/4/MRN-3085View Article Google Scholar

    Mycko, S., Kanno, Y., Bettinger, J. 2018 Using angling and electric fishing to estimate smallmouth bass abundance in a river. Fish. Manage. Ecol. 25(1): 77–84.
    DOI: 10.1111/fme.12269View Article Google Scholar

    O'Neal, J. 2007 Fyke nets (in lentic habitats and estuaries). In: Johnson, D.H.B., Jennifer M.S., (ed.), Salmonid Field Protocols Handbook, Techniques for Assessing Status and Trends in Salmon and Trout Populations, Bethesda: American Fisheries Society.

    Penczak, T., G?owacki, ?. 2008 Evaluation of electrofishing efficiency in a stream under natural and regulated conditions. Aquat. Living Resour. 21(3): 329–337
    DOI: 10.1051/alr:2008044View Article Google Scholar

    Reynolds, J.B. 1996 Electrofishing. In: Murphy, B.R., Willis, D.W. (eds.), Fisheries Techniques, 2nd edition, 221–254, American Fisheries Society, Bethesda, MD.

    Ruetz, C., Uzarski, D., Krueger, D., Rutherford, E. 2007 Sampling a littoral fish assemblage: Comparison of small-mesh fyke netting and boat electrofishing. North American Journal of Fisheries Management 27(3): 825–831.
    DOI: 10.1577/M06-147.1View Article Google Scholar

    Rytwinski, T., Taylor, J.J., Donaldson, L.A.J.R. Britton, D.R., Browne, Gresswell, R.E., Cooke S.J. 2019 Tthe effectiveness of non-native fish removal techniques in freshwater ecosystem : A systematic review. Environ. Rev. 27(1): 1–24.
    DOI: 10.1139/er-2018-0049View Article Google Scholar

    Snyder, D.E. 2003 Electrofishing and its harmful effects on fish. Information and Technology Report.

    Weaver, J.C. 1993 Electroporation: A general phenomenon for manipulating cells and tissues. J. Cell. Biochem. 51(4): 426–435.
    DOI: 10.1002/jcb.2400510407View Article Google Scholar

    Yemane, D., Field, J.G., Leslie, R.W. 2005 Exploring the effects of fishing on fish assemblages using abundance biomass comparison (abc) curves. ICES J. Mar. Sci. 62(3): 374–379.
    DOI: 10.1016/j.icesjms.2005.01.009View Article Google Scholar