粤西海域浮游植物种类的动态变化及多样性

根据1998～1999年4个航次粤西海域浮游植物的调查资料，分析了该海域浮游植物的种类组成、季节变化和平面分布特征，并对浮游植物的多样性水平进行了初步评价。结果显示，调查期间共鉴定浮游植物267种，其种类组成以细弱海链藻(Thalassiosira subtilis)的数量最多，占总数量的29．5％，其次为短角弯角藻(Eucampia zoodiacus)，占21．8％。不同季节浮游植物的优势种即有交叉又有演替。根据多样性阈值的评价，粤西海域绝大部分沿岸水域的浮游植物均处于多样性差或一般水平，而离岸水域基本处于多样性丰富或非常丰富水平。

Dynamic variation and the biodiversity for the species of phytoplankton in West Guangdong Waters

Based on the surveying data on phytoplankton in 4 cruises in West Guangdong waters from 1998 to 1999, the species (composition), seasonal variation and horizontal distribution characteristics of phytoplankton in the waters were analyzed, and as well the biodiversity level was preliminarily evaluated. The (result) showed that altogether 267 species of phytoplankton were identified (during) the survey. In the species composition, Thalassiosira subtilis was the highest in cell (quantity) with 29.5% of the total, and followed by Eucampia zoodiacus with 21.8%. Both the crossover and succession occurred in the predominant (species) in the (different) seasons. The evaluation on the diversity threshold showed that the diversity level of phytoplankton was poor in most of the coastal waters along West Guangdong, while it was rich in the offshore waters.