圖書典藏及影音數位平台

為了維護居民生命財產安全及發展經濟，多年來興設許水利構造物，無形中卻也影響河川環境生態。為降低工程的負面影響，水利署近幾年來努力尋找生物與環境間的關係，即是希望透過此一關係瞭解工程設置或相關管理措施對生物所造成的影響。過去曾嘗試辦理魚類適合度曲線的相關研究，以流速、水深及底床粒徑等工程人員孰悉的參數，透過調查、統計建立魚類適合度(喜好)的關係曲線，水利工程人員僅需透過水理模式即可瞭解工程設施對水理條件的影響進而推求魚類適合度的變化，相關曲線目前已有相當廣泛的應用。惟過去僅針對頭前溪、烏溪、楠梓仙溪等建置魚類適合度曲線，未能含括多數的臺灣原生魚類，且相同魚類在不同溪流亦有不同的曲線，因此本計畫將擴大辦理，並增加魚類生活史的探討，瞭解原生魚種生殖周期與對於自然棲地的選擇及偏好，以補充水理參數外的相關資訊，作為水利工程規劃及河川經營管理亟需的基本生物參數。除將相關成果建置資料庫以方便管理使用外，也將研擬魚類棲地適合度調查技術作業手冊，使調查方法與努力量標準化，讓後續的調查能有一定的品質要求與依據。

The Beinan River administered by central government located in the east Taiwan was selected for study reach. We made monthly collections and investigation of fish from April to December 2015. The Onychostoma alticorpus was sampled by electric method with 319 specimens in major and other methods in minor for life histories, and 600 sampling grids(1.5 m × 3.0 m) were sampled with electro-fishing at 60 stations, each with 10 grids for habitat suitability curve(HSC). The collected specimens numbers and external morphology are recorded including BL (body length), TL (total length), body weight, and the second sexual symbols such as nuptial tubercles and nuptial coloration. The reproduction hole is examined for sperm or ovum also appearance by rubbing the belly softly. The fish sample is soaked in 75% alcoholic solution and carried back to laboratory. The captured fish sample is rinsed and anatomized, the sexual distinction, total length, weight, and gonad weight is documented. For near matured female individuals, a unit weight of ovary is collected for measuring egg counts and diameters. The total length (TL), Hepatosomatic index (HSI, HIS%), gonadosomatic index (GSI, GSI%), and condition factor (CF%) for captured fish were analyzed and used for judgment on sexual ratio, breeding season, and life history. However, It can’t identify the breeding period now because of the project need more time to complete year cycle.On the fish micro-habitat investigation, a total of 12 species which belong to 4 families of fishes with 1081 specimens were collected in the end of the investigated. The population of dominant fish is Opsariichthys pachycephalus（46%）. During the investigation, the ranged of water pH is between 7.68 to 9.65, conductivity of water is between 427 μs/cm to 703 μs/cm, moreover, dissolved oxygen in water is between 6.12~11.66 mg/L. The water quality in samplings stations were classified as Category B except pH. The occurrences and CPUE（Catch Per Unit Effort）of O. pachycephalus, O. alticorpus, Rhinogobius gigas, R. candidianus and Sicyopterus japonicus were used for the establishment of water velocities, water depths and river substrate HSC. Besides, the standard operating procedures with electro-fishing grids was designed to assist the fish HSC investigations.