The Research of the Relationship Between Variations of the Fish Fauna and Water Quality of The Reservoir A Study of Feitsui Reservoir in Taiwan

魚類位於水生生物的食物鏈頂層，涵蓋營養階層廣，所以與水質的變化有密切的關係。翡翠水庫為台灣北部重要的集水區，自1988年起持續有生物監測計畫，但在2000年後即無魚類與水質關係之研究。本研究目的為調查目前翡翠水庫魚類相，並探討魚種數量變化與水質之關係，以提供翡翠水庫管理單位永續經營管理的參考資料之ㄧ。 翡翠水庫內不同水域的魚類相調查分為水庫內與金瓜寮溪、北勢溪、魚逮魚崛溪上游三條支流兩部分。前者以流刺網法，後者以複合性漁法捕獲魚類。並且以相似性指數及重量、尾數百分比計算魚類密度，探討自2006/6至2007/5計一年間的魚種組成，且與歷年文獻資料比較其變化趨勢。再將每季捕獲魚種重量、魚種密度及生物整合指數，與總磷、葉綠素a、透明度等水質優養化三項因子進行相關性分析，研究不同水域魚種數量變化與水質之關係。 研究結果顯示，六年前仍存在的中大型優勢魚種高身鯽及黑鰱的捕獲重量百分已明顯降低，而紅鰭鮊與雜交吳郭魚有取代高身鯽成為水庫內優勢魚種的趨勢。小型魚種大眼華鯿及 條的數量百分比最高，其中 條與斑駁尖塘鱧為2006年在水庫內第一次被捕獲的外來魚種。黑鰱、鯉魚、高身鯽等中大型鯉科魚類，分別在春季與夏秋季時與葉綠素a的相關性較高，判斷應與食性有關。原為肉食性的紅鰭鮊，由2006年的食性分析結果，攝食藍綠藻的比例高達91%，推測魚類食性在不同水域可能隨水質環境而有所改變。由生物整合指數結果顯示，水庫內指數較2000年以前為高，原因可能為肉食性魚種增多。 由於2000至2006年外來魚種增加，生態相可能逐漸產生改變，建議應持續監測魚類相的變化，以建立魚類與水質之連續性關係資料。The fish contains the wide ranges of nutrition and is located at the high level of the food chain of the aquatic, so the fish has close relations with the change of water quality. Feitsui Reservoir is one of the important collection watersheds in the north of Taiwan. It have had successively biology monitored plan successively since 1988, but reported no researches of relation between fish and water quality after 2000. The object of this study is to investigate the varieties of the fish and study the relation between the variations of fish mass and water quality in order to offer one of the sustainable use references for the Feitsui Reservoir administrations. For the investigation of fish in Feitsui Reservoir watersheds are had divided into the the two parts areas study including the Feitsui reservoir upstream tributaries of Beishih, Daiyujyue and Jingualiao respectively. The former sampling fish is used gill net and the latter is used composite method to fish. Calculating the density of fish makes use of Moristia index, percentage of weight and number, respectively, we studied the composition of the fish during 2006/6~2007/5 compared to the tendency of the fish variations over the years in the study areas. We research the relation between the variations of fish number and water quality in different streams with analyzing the correlation with six parameters, including the weight, density and index of biotic integrity of fish, total phosphorus, chlorophyll-a, transparency of eutrophication factors per month. The result of this study shows that percentage of catching weight from the original dominant species of larger cyprinids, Sinibrama macrops, Carassius cuvieri six years ago, were lower than that prior to 2000 obviously and Culter erythropterus and Oreochromis sp. have replaced Carassius cuvieri to become the new dominant species in Feitsui Reservoir. In the small size fish, the number of Sinibrama macrops and Hemiculter leucisculus is the highest. In the first time, Hemiculter leucisculus and Oxyeleotris marmoratus are the new non-native species in Feitsui Reservoir, 2006. The larger cyprinids Sinibrama macrops, Cyprinus carpio carpio, Carassius cuvieri have the higher correlation with chlorophyll-a in spring, summer and autumn separately. This phenomenon possibly comes from the feeding habits. According to analyzing the feeding habit of Culter erythropterus in 2006, Cyanobacteria getting up to 91% was the staple of the original carnivorous Culter erythropterus diet, and we presume that feeding habits of fish will change with water quality in different regions. The result of index of biotic integrity in reservoir showed that the index was higher than 2000, and the cause was that the species of carnivorous fish is increasing gradually. The ecosystem may be produced and changed gradually due to the raising of non-native species during 2000~2006. We propose that the monitoring of variation in the condition of fish should be carry out continually, and establish the continuous, correlative information between fish and water quality.學位考試委員審定書…………………………………………………… i 謝誌……………………………………………………………………… ii 中文摘要………………………………………………………………… iii 英文摘要………………………………………………………………… iv 目錄……………………………………………………………………… vi 表目錄…………………………………………………………………… ix 圖目錄…………………………………………………………………… x 第一章 前言…………………………………………………………… 1 1.1研究動機與目的………………………………………………… 1 1.2研究內容與流程………………………………………………… 3 第二章 文獻回顧……………………………………………………… 4 2.1水質優養化因子………………………………………………… 4 2.2魚類數量對水質的影響………………………………………… 5 2.2.1 鯉科魚類的影響………………………………………… 7 2.2.2 濾食性魚類的影響……………………………………… 11 2.3生物指數………………………………………………………… 13 2.3.1 生物整合指數…………………………………………… 13 2.3.2 相似性指數……………………………………………… 17 2.4 翡翠水庫水質與魚類………………………………………… 19 2.4.1水庫水質與魚類………………………………………… 19 2.4.2 上游支流水質與魚類…………………………………… 21 第三章 研究材料與方法……………………………………………… 23 3.1 研究地點……………………………………………………… 23 3.2 現場採樣方式………………………………………………… 25 3.2.1水庫魚類採樣方式……………………………………… 25 3.2.2上游支流魚類採樣方式………………………………… 26 3.3資料分析方法…………………………………………………… 29 3.3.1魚類相變化……………………………………………… 29 3.3.2魚類與水質相關性分析………………………………… 29 第四章 結果與討論…………………………………………………… 33 4.1魚類相之組成與變化…………………………………………… 33 4.1.1各水域魚類相之組成…………………………………… 33 4.1.2 水域別相似性指數的變化……………………………… 37 4.1.3 翡翠水庫魚種組成比例變化…………………………… 39 4.1.4 上游支流魚種組成比例變化…………………………… 43 4.1.5 魚種齡期………………………………………………… 46 4.1.6 魚種食性分析…………………………………………… 48 4.2 魚種數量與水質的關係……………………………………… 50 4.2.1歷年魚種數量變化文獻資料與水質關係……………… 50 4.2.2本研究調查魚種密度與水質關係……………………… 52 4.3魚類生物指數與水質關係……………………………………… 57 4.3.1翡翠水庫魚類生物整合指數的建立…………………… 57 4.3.2上游支流魚類生物整合指數的建立…………………… 60 4.3.3魚類生物整合指數與水質關係………………………… 62 第五章 結論與建議…………………………………………………… 65 5.1結論……………………………………………………………… 65 5.2建議……………………………………………………………… 67 參考文獻………………………………………………………………… 68 附錄 附錄一 流刺網設置位置及空間分布………………………………附錄1-1 附錄二 翡翠水庫內及其上游支流捕獲魚種………………………附錄2-1 附錄三 現場實驗照片………………………………………………附錄3-