摘要:通過研究貴州省龍灘水庫生態網箱養殖水體和庫區水體的特性,分析了水體中葉綠素a含量的動態變化及其與環境因子的相關關系。結果表明,生態網箱在一定程度上促進了葉綠素a含量的上升,改變了葉綠素a與環境因子的相關程度。現階段庫區和生態網箱養殖水體富營養指數均屬于中營養水平,分別為37.2、38.1,無顯著差異(P>0.05),生態網箱養殖對水庫水體無明顯影響。
關鍵詞:生態網箱;葉綠素a;環境因子;龍灘水庫
中圖分類號:X832 文獻標識碼:A 文章編號:0439-8114(2011)23-4834-05
Dynamic Change of Chlorophyll-a Concentration and Its Effect on Reservoir Environment in Ecological Cage Culture
YAN Jun1,LIU Li-ping1,LI Qiu-hua2,JAMES S. Diana3,ZHANG Jian4,WU Zong-wen5
(1. State Education Ministry Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Shanghai Ocean University, Shanghai 201306, China; 2. Guizhou Provincial Key Laboratory for Information System of Mountainous Areas and Protection of Ecological Environment, Guizhou Normal University, Guiyang 550001, China; 3. School of Natural Resources and Environment, University of Michigan, Michigan Ann Arbor 48109, USA; 4. Guizhou Luodian Spark Ecological Aquaculture Company, Luodian 551100, Guizhou, China; 5. Tongwei Co., Ltd., Chengdu 610041, China)
Abstract: The water characters of net cage and Longtan reservoir were studied to investigate the dynamic variation of chlorophyll-a concentration and analyze the relationship between chlorophyll-a concentration and environment factors. The results indicated that cage culture promoted the growth of chlorophyll-a and altered the relation between chlorophyll-a and environment factors. The eutrophication index of water body in net cage and reservoir were 37.2 and 38.1, which showed that both water body were at mesotrophic level and eco-net cage culture had no significant effect on the water body of reservoir.
Key words: cage culture; chlorophyll-a; environmental factors; Longtan reservoir
網箱養殖是一種高密度、機動靈活、水域適應性強的水產養殖方式。我國水庫資源豐富,具有大量良好養殖條件的水庫水域使水庫養殖迅速發展,但隨著養殖規模和養殖強度的不斷擴大,網箱養殖帶來富含氮、磷等營養物質的飼料殘餌和魚類排泄物向水域大量釋放,造成水庫水環境的富營養化,甚至造成水華的發生[1-6]。葉綠素a含量不僅可以表征藻類現存量[7],也是水體富營養化的重要體現,作為水體理化和生物指標的綜合表現,其本身亦受環境因子的影響[8,9]。因此,研究葉綠素a含量的時空分布及與環境因子的關系,分析庫區與生態網箱養殖區水環境因子的差異性,對認識水庫富營養化機理和科學合理地發展水庫網箱養殖有重要意義。
本試驗以貴州省龍灘水庫羅甸段網箱養殖基地生態養殖網箱為研究對象,以2010年7~12月間網箱養殖整周期水質檢測數據為基礎,對比研究水庫生態網箱養殖區與庫區葉綠素a的時空分布特征和水環境因子動態特征,同時采用富營養指數法評價龍灘水庫水體水質營養狀態,估計生態網箱養殖對水體富營養化的影響程度。……