EVALUATING EFFECT OF PORTABLE FISHWAY INSTALLATION ON THE INSTREAM DISTRIBUTION OF <i>PLECOGLOSSUS ALTIVELIS ALTIVELIS</i> IN THE HIWASA RIVER, TOKUSHIMA PREFECTURE

DOI

Bibliographic Information

Other Title
  • 徳島県日和佐川における可搬魚道の設置がアユの河川内分布におよぼす効果

Description

<p>We tested the effects of portable fishway installation in restoring upstream population of the Ayu Plecoglossus altivelis altivelis in the Hiwasa River, Japan. Roughly 60000 and 350 Ayu ascended through the portable fishway in 2018 and 2019, respectively. Density of Ayu in 2018 compared to those in 2017 was higher in the upper reaches while lower in the lower reaches, insisting that the portable fishway installation helped restoring the longitudinal connectivity for the fish species. In contrast, fishway installation of the same type in 2019 did not assist upstream migration of the fish as in 2018, partly due to the lower number of recruitments in the year and difficulty in gathering fish around the fishway entrance. Results of environmental DNA analysis correlated with snorkel counts in May 2019 but not in September 2019 in the river. Continued surveys are needed to clarify the effects of portable fishway installation in rehabilitating longitudinal connectivity in the river, as the recruitment of the fish change annually.</p>

Journal

Keywords

Details 詳細情報について

  • CRID
    1390573242800338432
  • DOI
    10.11532/river.26.0_379
  • ISSN
    24366714
  • Text Lang
    ja
  • Data Source
    • JaLC
  • Abstract License Flag
    Allowed

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