水下攝影監測生態水路枯水期亞臨界流況魚類族群的分布

Monitoring the Fish Population in Subcritical Flow Ecological Channel in Dry Season by Underwater Video Techniques

虞淨卉(Ching-Hui Yu) ； 張文亮(Wen-Lian Chang)

《農業工程學報》 56卷4期 (2010/12) Pp. 83-97

https://doi.org/10.29974/JTAE.201012.0007

摘要

本研究以雙鏡頭水下攝影技術，對苗栗穿龍圳東河排水之生態工程渠段進行非侵入性的魚類族群監測。
計算各採樣點之魚通量（單位時間單位體積魚隻數量，本研究爲：隻／0.007立方公•sec）：魚通量的概念能將不同能見度之各採樣點相互比較，其值受到棲地物理條件如遮蔽、水深與拍攝時段等影響。
貝氏有限混合分佈理論以魚通量作權重，繪製不同魚種之最適福祿數曲線，尋找交點得到不同魚種之適合福祿數範圍。研究發現，福祿數爲0至0.06之間爲大肚魚（觀測之平均體長爲2.0cm）優勢區：福祿數0.06至0.18爲台灣石（魚賓）（觀測之平均體長爲2.4cm）佔優勢：超過福祿數0.18則台灣馬口魚（觀測之平均體長爲1.8cm）佔優勢。魚隻成熟度會影響其魚種在不同福祿數下之表現，而本研究所觀察魚隻主要處於幼魚階段。
野外各點在影片中由人工觀測魚類棲所行爲判定爲棲息地的變異係數CV值皆小於1，也就是標準差小於平均值之情況爲魚類棲息地的可能性較高：反之若標準差大於平均值之情況則爲廊道的可能性較高。

關鍵字

台灣馬口魚 ； 台灣石（鱼賓） ； 大肚魚 ； 生態工程 ； 影像監測

並列摘要

This study used non-invasive bi-camera underwater video techniques to monitor the fish population in ecological engincering channel sections in Chuan-Long channel in Miaoli County.
The experiment recognized the fish species and calculated the fish flux (fish number/unit of volume unit of time, in this study it is fish number/0.007 m^3•sec) in different ecological engineering channel sections. The fish flux could compare with different sites with different visibility. The fish flux was affected by different factors such as surrounding conditions of habitats like shelter, water depth and different filming time, etc.
By using Bayesian finite mixture distribution as the method and the fish flux index as weight values, the experiment estimated the optimum-Froude number curves in different species in order to find the intersection points. The results showed that the Gambusia affinis affinis (the observed average body length is 2.0 cm) predominated over other species when the Froude number was 0-0.06. The Acrossocheilus paradoxus (the observed average body length it 2.4 cm) predominated over other species when the Froude number was 0.06-0.18. The Candidia barbata (the observed average body length is 1.8 cm) predominated over other species when the Froude number was higher than 0.18. The fish maturity affected the performances in different Froude number, and most of she observed fish in this study is in juvenile stage.
The coefficients of variance of fish flux were smaller than 1 in the study sites which were judgment artificially to be habitats by behavior of fishes. That was to say, when the standard deviations were smaller than means of fish flux, the sites might more likely be fish habitats but corridors.

並列關鍵字

Candidia barbata ； Acrossocheilus paradoxus ； Gambusia affinis affinis ； Ecological engineering ； Video monitor