Effects of thermal effluents from a power station on bacteria and heterotrophic nanoflagellates in coastal waters
Effects of thermal effluents from a power station on bacteria and heterotrophic nanoflagellates in coastal waters
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DOI：
10.3354/meps229001
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发表时间：
2002-03
影响因子：
2.5
通讯作者：
D. Choi;Jong Soo Park;C. Hwang;S. Huh;B. Cho
中科院分区：
文献类型：
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作者：
D. Choi;Jong Soo Park;C. Hwang;S. Huh;B. Cho
为了研究沿海发电站热排出物对邻近近岸水域细菌和异养纳米鞭毛虫的影响，于1998年11月和1999年7月、8月和11月在韩国河东发电站附近研究了细菌和异养纳米鞭毛虫的表面分布以及微生物和环境变量之间的相互关系。此外，还进行了高温(40℃；电站冷却系统温度)处理、投加次氯酸盐的操作实验和热力排出水与进水口的稀释实验。泄洪道的水温总是比环境温度高5~10℃，但细菌产量、HNF丰度和对细菌的捕食率以及叶绿素a浓度总是较低，并随着距离电站的增加而增加。操作实验表明，添加次氯酸盐对细菌和HNF的危害(在0.13ppm余氯时，细菌产量的抑制率为95%~98%，HNF的丰度下降25%~45%)比高温(40℃时细菌产量的抑制率为9%~39%，HNF的丰度没有抑制)要大得多。出水口和冷凝器管的热排出物与进水海水稀释后会产生0.03ppm的余氯，但热排出物对细菌的产生和HNF的放牧活性有抑制作用(对细菌产生的抑制率为23%~69%，对HNF的放牧抑制率为31%~36%)，表明排放水中的氯化副产物对沿海微生物有抑制作用。对微生物变量的水平分布、操作和稀释实验的分析表明，热排出物对细菌和HNF的抑制作用一致。我们的工作表明，微生物生态学方法在估计热污染对水环境中微生物的影响方面是有用的。
To investigate effects of thermal effluents from a coastal power station on bacteria and heterotrophic nanoflagellates (HNF) in adjacent coastal waters, surface distributions of bacteria and HNF and interrelations between microbial and environmental variables were studied in November 1998 and July, August and November 1999 near Hadong Power Station, Korea. In addition, manipu- lation experiments with treatments of high temperature (40°C; temperature in the cooling system of the power station) and additions of hypochlorite and dilution experiments of thermal effluents with intake seawaters were carried out. Water temperature in the discharge-channel was always 5 to 10°C higher than the ambient temperature, but bacterial production, HNF abundance and grazing rates on bacteria, as well as chlorophyll a concentrations, were always lower there and increased with dis- tance from the power station. Manipulation experiments showed that addition of hypochlorite had much more deleterious effects on bacteria and HNF (95 to 98% inhibition of bacterial production and 25 to 45% decrease in HNF abundance at 0.13 ppm of residual chlorine) than high temperature (9 to 39% inhibition of bacterial production but no inhibition of HNF abundance at 40°C). Dilutions of thermal effluents from the outlet and condenser tube with intake seawater would bring <0.03 ppm of residual chlorine, but inhibitory effects of thermal effluents on bacterial production and HNF grazing activity (23 to 69% inhibition of bacterial production and 31 to 36% inhibition of HNF grazing) were shown, indicating inhibitory potential of chlorination by-products in the discharged water on coastal microbes. Analyses of horizontal distributions of microbial variables, manipulation and dilution experiments gave consistently similar results of inhibitory effects of thermal effluents on bacteria and HNF. Our work suggests that a microbial ecological approach is useful in estimating influences of thermal pollution on microbes in aquatic environments.