澳门湿地浮游植物群落特征

CHARACTERISTICS OF THE PHYTOPLANKTON COMMUNITY IN WETLANDS OF MACAO

2007年7月、10月和2008年1月,对澳门的湿地——筷子基湾、白鹭林、莲花大桥滩涂和南湾湖的浮游植物群落特征进行了调查。3次采样共检测到76种(属),其中,蓝藻门藻类13种(属),绿藻门30种(属),硅藻门25种(属),甲藻门2种,裸藻门4种,金藻门和隐藻门各1种(属)。浮游植物丰度的最高值出现在莲花大桥,为3922.33×104cells·L–1;最小值出现在南湾湖,为1.58×104cells·L–1。浮游植物主要是由蓝藻、绿藻、裸藻和硅藻组成。2008年1月硅藻的含量最高,而2007年7月蓝藻的含量最高。浮游植物多样性指数和均匀度指数值均指示出:筷子基湾2008年1月、莲花大桥2007年7月和10月污染最严重,其他属于中度污染或无污染。透明度对澳门湿地浮游植物的影响较大,与绿藻(r=0.683,p<0.05)、甲藻(r=0.715,p<0.05)、金藻(r=0.707,p<0.05)和隐藻(r=0.701,p<0.05)都存在较高的正相关关系。硅藻与pH值存在较强的负相关关系(r=-0.674,p<0.05),与总氮(r=0.895,p<0.05)、总磷(r=0.920,p<0.05)和正磷酸(r=0.668,p<0.05)存在较强的正相关关系。

Aims Our objectives were to understand the structure of the phytoplankton community and the relationships between phytoplankton abundance and environmental factors in wetlands of Macao. Methods Water and phytoplankton samples were collected in July and October 2007 and January 2008 at the four sites of Fai Chi Kci Bay, Taipa-colonva mudflats, Lotus Flower Bridge and Praia Grande Lake. Phytoplankton was fixed with formaldehyde with a fmal concentration of 3%-5% （v/v）. Water temperature, conductivity, dissolved oxygen were measured in situ with 85- Ⅱ YSI Multiparameter Water Quality Monitor. Water transparency was determined with Secchi Disk Depth. Water pH was measured with pHS-3C acid-alkalinity parameter Water Quality Monitor. Chlorophyll a was obtained from a sample of 400 ml water filtered through a Whatman GF/A filter. Concentrations were determined after〈8 h extraction in 90% acetone. Nutrient concentrations were measured by using GB3838-2002. Important findings Cyanobacteria, chlorophytes and diatoms had the largest numbers of species. We identified 76 species of algae, including 13 species of Cyanophyta, 30 species of Chlorophyta and 25 species of Bacillafiophyta. Maximum abundance was at Lotus flower bridge （3 922.33 ×10^4cells·L^-1） and maximum abundance of Cyanophyta was in July and Bacillariophyta was in January. Minimum abundance was at Praia Grande Lake （1.58×10^4cells·L^-1）. Values of the Shannon-Wiener Index of diversity indicated that Fai Chi Kei Bay was seriously polluted in January and Lotus Flower Bridge in July and October, while others were little or moderately polluted. Water transparency was the most im-portant environmental factor affecting phytoplankton dynamics at the four wetlands and was strongly positively correlated to Chlorophyta （r=0.683, p〈0.05）, Pyrrophyta （r=0.715, p〈0.05）, Cryptophyta （r=0.707, p〈0.05） and Chrysophyta （r=0.701, p〈0.05）. Bacillariophyta was negatively correlated to pH value （r=-0.674, p〈0.05） and positively correlated to total nitrogen （r=0.895, p〈0.05）, total phosphorus （r=0.920, p〈0.05） and soluble reactive phosphorus （r=0.668, p〈0.05）.