广州市谷河黑臭评价及其与裸藻丰度和生物量相关性分析

藻类密度增加是黑臭现象发生的重要原因之一.目前的黑臭评价标准缺少藻类等水生生物指标,而黑臭河流中浮游微藻时空特征研究也极少.于2017年秋和2018年冬和春在谷河布设6个样点,采用污染指数法(I_1)和黑臭多因子加权指数法(I_2)评价谷河黑臭情况,同时调查浮游微藻的丰度和生物量等,并对黑臭评价结果和微藻进行Pearson相关分析.结果表明,I_2指数法更适合评价谷河的黑臭情况;裸藻门丰度与I_2的相关系数较高(r=0.784,p0.01);裸藻门丰度比例和生物量比例与I_2的相关系数分别为0.750和0.776(p0.01);裸藻门的种数和裸藻门污染指示种个数与I_2的相关系数均为0.623(p0.01).裸藻门可能适合于作为评价谷河黑臭的水生生物指标.天然水体中微藻或裸藻与致臭物质的产生等有待深入研究.

Evaluation on black-odorous water related with Euglenophyta abundance and biomass in the Gu River of Guangzhou City

Increased algae abundance was one of the important reasons for black-odor river. However, current criteria for black-odorous water assessment lacked indicators of aquatic organisms, such as algal, and few studies were carried out to investigate the spatial-temporal characteristics of planktonic algae in black-odorous rivers. Six sites were located in the Gu River, which were sampled in autumn 2017, winter and spring in 2018, respectively. To evaluate the black-odorous water in the Gu River, the pollution index (I₁) and black-odor index with multi-factors (I₂) were used. At the same time, planktonic algal abundance and biomass in the water were measured, and Pearson correlation analysis was used to determine the relationship between black-odorous water and planktonic algal. The results showed that I₂ were more suitable for assessing the Gu River. The higher positive correlation was observed between Euglena abundance and I₂ (r=0.784, p<0.01). There are positive correlations between I₂ with Euglenophyta abundance percentage (r=0.750, p<0.01) as well as biomass percentage (r=0.776, p<0.01). Also, the I₂ was positively related to species numbers as well as pollution-indicating species numbers of Euglenophyta, both with the correlation coefficient of 0.623 (p<0.01). Therefore, Euglenophyta could be considered as possibly aquatic monitoring indicators of the Gu River. Further research is needed to determine the interaction of algae or Euglenophyta with production of odor compounds in natural waters.