春、夏两季东山湾不同区域异养细菌的分布及其影响因子

Horizontal distribution characteristics and influencing factors of heterotrophic bacterial abundance in Dongshan Bay in spring and summer

于2011年5月—8月对东山湾春、夏两季水体中异养细菌丰度进行调查,并探讨相关环境因子对异养细菌丰度的影响。结果表明:东山湾夏季水体异养细菌平均丰度为2.82×103mL-1略高于春季2.05×103mL-1,其中春季水体中异养细菌平均丰度为表层>底层>中层,而夏季水体中异养细菌丰度表、中、底层分布较均匀。春季东山湾水体中异养细菌丰度以龙须菜养殖区最高,而夏季以湾口区和鱼类网箱养殖区较高。相关性分析显示春季表层水体中异养细菌丰度与叶绿素a、DO、COD含量呈显著的正相关,夏季则与活性磷酸盐呈显著的正相关,同时,春夏两季底层水体异养细菌丰度与所测环境因子无显著的相关性。根据海水水质标准,以异养细菌丰度作为评价指标表明东山湾受陆源污染的程度较轻。

Based on two cruises which dated from May 2011 to August 2011 , the abundance of heterotrophic bacteria in Dongshan Bay were studied. Moreover, the relationship between the bacterial abundance and the environmental ecological factors was also analyzed. The results showed that the mean bacterial abundance in Dongshan Bay in spring and summer were 2. 05 × 103 mL-1 and 2. 82 × 103 mL-1 respectively. The bacteria a-bundance of bottom water in Dongshan Bay was less than that of surface water, and more than that of middle water in spring, while the bacteria abundance of surface and middle and bottom water were well distributed in summer. Besides, the bacterial abundance in the Gracilaria lemaneiformis culture area was highest in spring in Dongshan Bay, while that in the mouth area and fish-cage area were higher than othe area in summer. The correlation analysis showed that the bacterial abundance had significont positive corelation with the concentra-tion of chlorophyll-a, dissolved oxygen （ DO） and COD in spring and alco had significont positive correlation with the conlentration of active phosphate in summer. Meanwhile there was no significant correlation between the bottom of the bacteria abundance and the environmental ecological factors. Based on the standard of sea-water, it showed that Dongshan Bay was less affected by terrestrial pollution using the number of heterotrophic bacteria as evaluating indicator.