Diel Vertical Distribution of Zooplankton in Lake Baringo, Kenya

作     者：Reuben Omondi Andrew W. Yasindi Adiel M. Magana 

作者机构：Kenya Marine & Fisheries Research Institute Kisumu 40100 Kenya Department of Biological Sciences Egerton University Egerton 20115 Kenya Department of Biological Sciences Chuka University College Chuka 60400 Kenya 

出 版 物：《生命科学：英文版》 

年 卷 期：2014年第8卷第5期

页      面：447-460页

学科分类：0710[理学-生物学] 082803[工学-农业生物环境与能源工程] 07[理学] 08[工学] 0828[工学-农业工程] 0804[工学-仪器科学与技术] 071004[理学-水生生物学] 

主　　题：浮游动物 垂直分布 昼夜 肯尼亚 溶解氧测定 生物计算 化学因素 溶解氧值 

摘      要：Diel zooplankton samples were obtained at a 4-m-deep central station on two sampling occasions in January and February, 2010 in Lake Baringo. Sampling was done at 1 m interval every four hours for 24 hours from 8:00 am to 04:00 am. Ten litres of lake water was collected by a Van Dorn sampler and sieved through a 50 μm mesh sieve and organisms in the entire sample counted. Concurrently, physico-chemical factors including temperature, pH, conductivity and dissolved oxygen were measured at the same depths in situ. In both sampling months, the temperatures were higher during the day when stratification was observed just below the 1 m depth. This was, however, broken by diurnal winds in the evenings. PH and dissolved oxygen values followed the same trend but conductivity was generally uniform. In contrast to what has been observed in clear water lakes, the densities of Lake Baringo zooplankton were generally higher at the surface waters during the day while during the night the organisms were distributed throughout the lake column, a phenomenon which could be attributed to the high waters turbidity. The Proximity of zooplankton to the euphotic zone during the day provides them with feeding opportunities on phytoplankton.