- 學位論文
應用無線電遙測技術及遺傳規劃法探討大屯溪台灣鏟頷魚日間活動性與流量水溫之關係
Application of radio telemetry and genetic programming to study the relationship among diurnal fish activity, water temperatures and streamflow : A case of Varicorhinus barbatulus in Datuan stream
摘要
溪流魚類棲息於不同環境條件及季節下，將反應其活動性變化與棲地喜好，其中以河川內水溫、流量影響最為顯著，將可改變魚類之生殖環境與活動行為。其中，魚類於生殖季節為使生理機能正常運作，需要在低水溫環境下進行生殖行為，故須考量其溫度容忍範圍。此外，過低之溪流量造成河川棲地不連續性，使魚類無法溯泳而上進行繁衍；颱風及豪雨後之高流量亦會造成上游棲地結構破壞，將魚類迅速沖至下游高水溫流域，最後使魚類受到下游攔河堰之阻隔而無法回到上游棲地，上述環境因子可造成魚類族群縮小與區隔化、洄游受阻等影響。 本研究利用無線電遙測技術，追蹤台灣鏟頷魚棲息於攔河堰之下游及上游河段之日間活動行為，藉此取代過去間歇性調查方式。利用訊號變異反應台灣鏟頷魚在不同時期內之行為策略、活動範圍與活動力，並將資料利用遺傳規劃法及迴歸分析建立魚類活動性與水溫、流量之關係方程式，探討台灣鏟頷魚其日間活動性與流量、水溫變數之關係，進一步推測魚類生態行為與河川棲地之相關特性。研究結果顯示，應用遺傳規劃法建立魚體活動性與流量、水溫變數之關係式中，水溫變數分析魚體活動性時之判定係數為 0.50，流量則為 0.47，而同時考量水溫及流量變數之判定係數能達到 0.76，且關係式之趨勢指出台灣鏟頷魚在水溫上昇時，其活動性將提高，每日以中午時段之活動性最高。而短期內微幅流量變化對台灣鏟頷魚活動性之影響不如水溫敏感，但流量明顯變化時，將提高魚體活動性。此外，攔河堰上游之魚體活動性與水溫、流量之間，比下游魚體具有更高相關性。整體而言，仍以水溫變化為影響魚體活動性之主要因素。本研究過程中之台灣鏟頷魚皆呈現強烈上溯特性，且活動性受到攔河堰之影響顯著，此亦說明河川工程會對魚類行為產生干擾，應審慎考量工程規劃，做為未來進行棲復育與河川生態工程規劃之參考依據。
並列摘要
Freshwater fish respond to seasonal variation in environmental conditions by altering patterns of activity and habitat selection, especially stream flow and water temperature. These environment variable change fish’s reproductive behavior and fish activity. For instance, fish search for appropriate habitats for spawn, usually in low-temperature environment. Furthermore, low stream flow rate make fragmentation of their habitat. Typhoon and heavy rainfall will decrease upstream fish habitat and fish rushed to the high water temperature basin, finally, the fish cumulated below the impassible weir, unable to return to the upstream habitat. To sum up, these environmental factors can decrease fish populations, segmentation and blocked fish migration. In this study, used radio-telemetry technology to investigate the diurnal fish activity of adult Varicorhinus barbatulus around a stream weir, we replaced the intermittent method of investigation. The use of signal strength variation as a measure of fish activity, differences in patterns of fish activity have significant implications for fish behavior strategy, home range and activity. The genetic programming and regression analysis were used to model the stream temperature, flow rate variations and fish activity, then compare these environment variable about Varicorhinus barbatulus, speculated the Varicorhinus barbatulus’s ecological characteristic.In the result, genetic programming establish a relationship among fish activity, temperature and flow rate. Considered all these environment variable, the result show that the coefficient of determination of water temperature was higher than stream flow rate, point out that fish activity will rise in high temperature, and the significant peak was during daylight around noon. The fish activity is sensitive to stream water