Empty Flushing Operation Effects on Fish Community Composition

Abstract

In order to realize the impact of the environmental factors on fish habitats this study analyzes fish and water quality data which are collected from 4 sample stations located in the upper middle and lower area in the Agongdian Reservoir from 2016 to 2019 It can be found that the water level dissolved oxygen and the pH value are related to fish diversity data Comparing the changes of the water level over the years and the fish community composition for the empty flushing period it is observed that the empty flushing operation turns out the increasing fish diversity in the third season At the peak fish diversity of the year it is thought that (1) the river appears more habitat diversity when the water level is low; (2) it is easier to capture the benthic fish when the water level is low; and (3) it is considered showing "Intermediate disturbance" that changed the competition between invasive and endemic fish species in the reservoir after the empty flushing operation Firstly the results of this study indicate that this operational method may improve the diversity of fish community and also reduce the number of invasive fish in the reservoir Secondly that are not only the extremely high benefits of sand discharge but also a certain degree of impact on fish by flushing operation The evenness index is the most obvious followed by the quantity and then the diversity index

Date of Award	2020
Original language	English
Supervisor	Jian-Ping Suen (Supervisor)