Xu Zijun and Zhang Hongliang, Branch of North China Sea, S.O.A

Abstract

On Aug. 8^th in 2001, we carried out the two groups of enclosed experiment of 25m³ water mass in the harbor of Ba Yu Quan. The water mass were acquired from harbor and the area out of the harbor. On 12nd, red tide broke out in the harbor and the sea area around it. The comparison of the enclosed experiment and investigation of red tide shows: In the enclosed experiment, different dominant species grew up in different water mass. The dominant species growing in the water mass from the harbor is Leptocylindrus danicus, same as the dominant species of the red tide investigated in the harbor. When the red tide disappeared, the dominant species succession in the harbor is similar to that of the enclosed water mass. According to the ecological investigating data of enclosed water masses and the surrounding environment before and after the red tide, this paper analyzes the relation not only between the red tide species of enclosed water mass and initial biocommunity, but also between the concentration of nutrient salt and biatom density and duration of the red tide. The study provides valuable reference to the red tide research.

Keywords: enclosed experiment, red tide