柱孢藻在金門水庫形成優勢之原因探討

Abstract

柱孢藻（Cylindrospermopsis raciborskii（Woloszynska） Seenaya et Subba Raju）是一種淡水藍綠藻，在金門的一些水庫裡有大量滋長的情況，並形成藻華而影響水庫之水質。本研究針對榮湖、金沙、山西及太湖水庫進行為期一年的現場生態調查，針對水庫環境與柱孢藻作相關分析，並研究柱孢藻分離株之生理特性，來探討此藻種優勢生長的原因。水庫現場調查結果發現，四個水庫中皆有柱孢藻優勢的情況，而水庫水質皆介於優養化到超優養化間，且庫水透明度低、導電度高、總磷及總氮高、略帶鹽度及含有機污染物。在柱孢藻分離株之生理研究發現，高濃度的硝酸氮、中高水溫（24~32℃）、低濃度銨氮(＜4 mM )及尿素，有利於柱孢藻生長，且此藻對鹽度有耐受性（~ 4

A filamentous freshwater cyanobacterium, Cylindrospermopsis raciborksii (Woloszynska) Seenaya et Subba Raju, was to be found dominant in some freshwater reservoirs. The water quality of the reservoirs in Kinmen was deteriorated due to the blooms of this organism. Physio-chemical analyses of water were carried out monthly in four reservoirs viz., Rong-lake, Jin-Sha, Shan-Xi and Tai-lake over the period from September, 2003 to September, 2004. Physio-chemical factors affecting the abundance of C. raciborskii in the reservoirs were analyzed. The growth physiology of C. raciborskii was studied with an isolate of this species. The results indicated that all of four reservoirs showed dominance of C. raciborskii, associated with low transparency, high electrical conductivity,low salinity, moderate organic pollutants and higher concentrations of both TN and TP. All of four water reservoirs were in eutrophic or hypertrophic condition. The isolate of C. raciborskii preferred high concentration of nitrate, low concentration of urea and moderate water temperature varying from 24