福建海区浮游植物种类组成及数量分布特点

The species composition and quantity distribution characteristics of phytoplankton in Fujian sea area

根据2003～2004年福建海区春季和夏季2个季度月浮游植物调查资料,分析和研究了该调查海区浮游植物种类组成和数量分布特点。结果表明:经鉴定浮游植物共有111种,其中硅藻类81种,占总种数的73.0%;浮游植物总生物量分布夏季比春季高,春季平均值为30.9×10~4 ind·m^(-3),夏季为2645.6×10~4 ind·m^(-3);春季总生物量以闽东渔场最高,闽中渔场最低,夏季则相反,随着暖流势力的增强,闽中、闽南-台湾浅滩总浮游植物生物量剧增,以闽南-台湾浅滩最高,闽中渔场其次,且密集区明显,最高生物量超过40000×10~4 ind·m^(-3);从数量组成看,以热带近海性种和热带外海高盐性种占绝对优势,优势种为劳氏角毛藻、掌状冠盖藻、斯托根管藻、铁氏束毛藻、汉氏束毛藻、地中海指管藻等;整个海区优势种明显,数量高,多样性指数和均匀度指数都较低;总生物量密集区与浮游动物密集区相一致,大部分为拖网、灯光围网等作业的主要渔场;与历史资料和邻近海域相比较,优势度指数年间变化较大,数量明显增加,但生物量密集区变化不大。

According to phytoplankton investigation data in spring and summer in Fujian sea area during 2003 to 2004, this paper analyzed and studied the species composition and quantity distribution characteristics in the area. The results showed that 111 species of phytoplankton were identified with 81 species of diatoms occupying 73.0% ; the total biomass of phytoplankton in summer was more than that in spring with average 30. 9 × 10^4 ind·m^-3 and 2 645.6 × 10^4 ind·m^-3, respectively. The total biomass of Mindong fishing ground in spring was highest, Minzhong fishing ground was lowest; but it was contrarily in summer. The total biomass in Minzhong and Minnan-Taiwan bank fishing ground obviously increased with boosting up by warm current, and Minnan-Taiwan bank fishing ground was highest and Minzhong fishing ground was followed with the obvious density area, the biomass was over 40 000 × 10^4 ind·m^-3. The dominant species were tropical near-oceanic group and tropical oceanic high-salinity group as Chaetoceros lorenzianus, Stephanopyxis palmerana, Rhizosolenia stolte（fothii, Trichodesmium thiebautii, Trichodesmium hildebrandtii and Dactylioselen mediterraneus. The species diversity index was low, but the quantity of dominant species was high. The dense areas of phytoplankton were the main fishing ground of trawler and light seine, Compared with the data of historical and adjacent waters, the fluctuation of majority index was large in years; the biomass of phytoplankton increased obviously but the dense area was changed slighly.