珠江口球形棕囊藻(Phaeocysis globosa)赤潮后期的浮游植物群落结构特征研究

Study on phytoplankton community structure at the late stage of a Phaeocystis globosa bloom in the Pearl River Estuary

研究小组于2009年11月30日至12月2日期间对珠江口一次球形棕囊藻（Phaeocystis globosa）赤潮后期的浮游植物群落结构特征进行了调查研究。共发现浮游植物（包括变种、变型）6门，57属，118种。其中，硅藻门26属67种，占总种数的56．77％；绿藻19属33种，占总种数的27．96％；甲藻4属6种：蓝藻4属5种；裸藻2属5种；金藻2属2种。调查期间，球形棕囊藻可视群体的直径范围为0．5-2．5cm，密度均值为1208 colonies·m^3，镜检的密度均值为675000 colonies·m^3。11月中旬至月底的骤然升温是本次球形棕囊藻赤潮爆发的主要原因。赤潮期间主要伴随优势种有骨条藻（Skeletonema sp．）、颗粒直链藻（Aulacoseira granulata）、新月菱形藻（Cylindrotheca closterium），以及三星裸藻（Euglena tritella）。

The characteristics of phytoplankton community structure in the Pearl River Estuary were studied at the late stage of a Phaeocystis globosa bloom from November 30 to December 2, 2009. Totally 118 species of microalgae belonging to six phyla were identified in the study. Among them, 67 species belonged to Bacillariophyta; 33 species belonged to Chlorophyta; 6 species belonged to Dinoflagellate; 5 species belonged to Cyanophyta; 5 species belonged to Euglenophyta; 2 species belonged to Chrysophyta. During the investigation, the diameter of optical colonies ranged from 0.5-2.5 cm, with an average density of 1208 colonies·m^3; and the average density under microscopic observation reached to 675000 colonies·m^3. The sudden rising of temperature from the mid to end of November might be the key factor causing the bloom. The accompanying dominant species during the bloom were Skeletonema sp., Aulacoseira granulata, Cylindrotheca closterium and Euglena tritella.