2014-02-012024-05-15https://scholars.lib.ntu.edu.tw/handle/123456789/664972摘要：日本鰻是東亞各國水產養殖的重要魚種之一，具有極高的經濟價值。雖然人工繁殖已在日本成功，但因成本過高而尚無法商業化量產，因此目前養殖所需的大量鰻苗仍然依賴天然捕撈，成為養殖產業的重大瓶頸。根據估計，亞洲地區現今的日本鰻資源量相較於1970年代而言，估計低於當年的10 ﹪(Han et al.，而在台灣，日本鰻族群在過去數十年間亦有顯著的降低情形。日本鰻主要的養殖國家為日本、中國、韓國、以及台灣，每年鰻苗的需求量約在80-100公噸左右，然而，近幾年鰻苗捕獲量頻創新低，一尾鰻苗身價甚至高達200元，困擾著整個東亞的鰻魚產業。因此，建立適當的日本鰻資源管理與復育方針，有效增加天然鰻苗之資源，是現階段鰻魚產業能夠永續發展的關鍵。 此外，因日本鰻資源量明顯不足，東亞各國近年來遂興起了異種鰻的養殖風潮，其中以鱸鰻以及雙色鰻 (俗稱短鰭鰻) 發展最速。台灣本地共產出五種鰻魚 (日本鰻、鱸鰻、短鰭鰻、黃氏鰻、西里伯斯鰻)，掌握這些鰻苗的生物地理分布以及資源現況，對於鰻魚資源管理與產業發展極有幫助。此外，行政院農業委員會自今年度起，依漁業法第四十四條第四款，公告全國鰻苗捕撈漁期管制規定，捕撈許可時間訂為11月初至2月底；另各縣市政府亦已公告轄內指定河川，禁止使用任何方式採捕體長8公分以上之鰻魚，讓野生鰻與放流鰻能夠順利降海產卵。因此，為了掌握國內鰻魚資源量與分布現況，本年度計畫大規模調查鰻魚保護河川中之鰻魚資源現況，以及河川生態棲地品質，藉以追蹤適當放流地區與評估鰻魚保育成效。 本年度目標為: (1) 普查台灣地區鰻苗資源與分布現況 (2) 普查台灣地區河川中之鰻魚資源與捕撈現況 (3) 評估蘭陽溪流域,鳳山溪流域以及高屏溪流域之鰻魚資源量 (4) 調查各縣市鰻魚保護河川棲地長期變遷 預期效益: (1) 掌握台灣各河川天然鰻魚(苗)資源的粗略現況。 (2) 掌握蘭陽溪流域,鳳山溪流域以及高屏溪流域鰻魚保護河川中之鰻魚資源現況：包括種類、資源量、性比、成長及成熟等生活史參數。 (3) 了解各河川鰻魚棲地品質之長期變遷，評估適當之保育熱點。 <br> Abstract: Japanese eel is an important aquaculture species in East Asia with high economic value. Although artificial propagation of the glass eel has been successful, the commercial scale of production still cannot been established yet due to high cost. Thus, the needed fries are all caught from the wild till now, resulting in a serious bottleneck for the eel aquaculture industry. It is estimated that the current eel resource in East Asia is less than 10% in comparing to that in year 1970s. Taiwan also suffers the same impact. The Japanese eel is mainly cultured in Taiwan, China, Korea, and Japan, with mean elvers demand about 80-100 metric tons annually. However, the amounts of glass eel catch in recent years decline rapidly, with one piece of glass eel even charging more than 200 NTD. This seriously bugs the eel aquaculture in East Asia. Thus, to manage and recover the valuable natural eel resource is a key for the sustainability of eel aquaculture industry. Furthermore, because the shortage of the Japanese eel, the aquaculture of other eel species has emerged in the recent years. A. marmorata and A. bicolor pacifica are most popular species. In Taiwan, there are a total of 5 eel species. Handling the biogeography and resource status is very helpful to eel resource management and industry development. This year the Council of Agriculture announces the regulation of glass eel catching. The glass eel are only allowed to be caught during Nov. 1st through Feb. 28th of the next year. Besides, all counties of Taiwan should choose at least one river as the eel protection river. Eel larger then 8cm are not allowed to be caught in order to protect the seawater migration of the wild and released eels. This project will evaluate the eel habitat quality and resource status of all eel protection rivers in order to evaluate the releasing benefit and habitat hot spots of the eel. The three goals of the project are: 1. To investigate resource status and distribution of the glass eel in Taiwan. 2. To investigate the eel resource status of all eel protection rivers in Taiwan. 3. To investigate the long-term change of the eel habitat quality of eel protection rivers. The predicted benefits of this project are: 1. To understand the current resource of the wild eels in Taiwan, including species composition, resource abundance, sex ratio, age and growth, etc. 2. To understand the long-term change of the eel habitat quality in eel protection rivers and identify the hot spots of the eel conservation.鰻魚資源量棲地評估EelResource AbundanceHabitat Evaluation