外伶仃海域龙须菜栽培对水质及浮游细菌数量的影响

Effect of Gracilaria lemaneiformis cultivation on water quality and bacterioplankton abundance of Wailingding Island coastal waters

目的：研究龙须菜栽培对水质及浮游细菌数量的影响.方法：2013年3-4月对珠海外伶仃岛龙须菜栽培区及邻近海域（对照区）进行了6次周际调查.结果：龙须菜栽培区浮游细菌数量平均值为（1.49±0.08）×10^（-6）ind./m L,对照区为（2.19±0.15）×10^6ind./m L,栽培区浮游细菌数量显著低于对照区（P〈0.01）;同时,龙须菜栽培区表层水体TN、DTN和DTP浓度显著低于对照区（P〈0.05）.相关性分析显示,浮游细菌数量与TN、DTN、DTP浓度显著正相关,与溶解氧和龙须菜栽培生物量显著负相关,与温度、盐度、TP浓度的相关性均不显著.结论：龙须菜栽培降低了表层水体氮、磷浓度,并使得栽培区浮游细菌数量低于对照区.

Aim：To examine the effect of Gracilaria lemaneiformis cultivation on water quality and bacterioplankton abundance. Methods： We surveyed bacterioplankton and the environmental factors in the coastal area of Wailingding Island for 6 consecutive weeks during March to April 2013. Results： The bacterioplankton abundance in the Gracilaria lemaneiformis cultivation zones （GZ,1.49×10^6 ind./mL） was significantly（P〈0.05） lower than that in control zones （CZ, 2.19×10^6 ind./mL）. Also, the average concentrations of total nitrogen （TN）, dissolved inorganic nitrogen （DTN） and dissolved inorganic phosphorous （DTP） in GZ were significantly lower than that in CZ （P〈0.05. In addition, the bacterioplankton abundance had a positively significant （P〈0.05） correlations with TN, DTN and DTP concentrations, but a negatively significant correlations with dissolved oxygen and Gracilaria lemaneiformis biomass （P〈0.01）, while there were no significant correlations between bacterioplankton abundance and temperature, salinity or TP. Conclusion：Gracilaria lemaneiformis cultivation not only reduced the concentrations of nutrient in the surficial sea water, but also decreased the bacterioplankton abundance.