大亚湾近代沉积物中甲藻孢囊的垂直分布  

VERTICAL DISTRIBUTION OF DINOFLAGELLATE RESTING CYSTS IN RECENT SEDIMENTS FROM DAYA BAY,THE SOUTH CHINA SEA

作　　者：王朝晖[1] 齐雨藻[1] 江天久[1] 许忠能[1] 

机构地区：[1]暨南大学水生生物研究所,广州510632

出　　处：《水生生物学报》2004年第5期504-510,共7页Acta Hydrobiologica Sinica

基　　金：国家自然科学基金 ( 4 0 3 0 60 2 0 );重大项目 ( 3 9790 110 );国家重点基础研究发展规划项目 ( 2 0 0 1CB40 970 0 )资助

摘　　要：用TFO采泥器于 2 0 0 1年 8月采集了大亚湾大鹏澳海域 6个采样点 8— 18cm柱状沉积物样品 ,分层研究了甲藻孢囊在该海域表层沉积物中的垂直分布。在 35个沉积物样品中共分析鉴定出甲藻孢囊 4 8种 ,其中自养型 2 0种 ,异养型 2 8种 ,优势种类为锥状斯氏藻。每个样品中所分析鉴定的孢囊种类数为 12— 2 9种 ,孢囊的香农—威弗种类多样性指数 (Shannon WeaverDiversityIndex,H′)为 0 6 1— 4 13,并且在 2— 4cm层次处 ,随深度的增加 ,两者均有一个明显上升趋势。除鱼类养殖区的上表层较高外 ,孢囊丰度大多为 10 0 0— 2 0 0 0cysts/gDWt,最高为 2 38× 10 4cysts/gDWt。亚历山大藻孢囊分布广泛且密度较高 ,最高丰度为 5 0 3cysts/gDWt,同时表层沉积物中高密度的亚历山大藻孢囊为该藻赤潮的发生提供了丰富的种源 ,而且也是该海域贝类体内冬季PSP毒素积累及高含量的重要原因。Six sediment cores from length of 8 to 18cm were collected from DapengAo area,Daya Bay,the South China Sea,by TFO core sampler in Aug. 2001 to investigate the vertical distribution of dinoflagellate resting cysts. 48 different cyst morphotypes representing 20 genera and 6 groups were identified from 35 sediment samples in this study. There were 20 autotrophic species and 28 heterotrophic ones. Cyst species richness in each sample varied from 12 to 29,while the values of Shannon-Weaver’s Diversity Index(H′)were between 0.61 and 4.13. There were an obvious increase of species richness and H'values in the depth of 2—4cm. Cyst concentrations varied from 154 to 2.38×104 cysts/g D Wt,and were between 1000 and 2000 cysts/g D Wt in most samples,while the highest concentration was obtained at the depth of 2—4cm in fish raised area of St.1.Scrippsiella trochoidea was the most common and abundant cyst type. Meanwhile,the abrupt increase of cysts of S. trochoidea in the depth of 2—4cm layer of sediment reflected the bloom of this species in nearby sea areas in 2000. The results from cyst assemblages showed some trend of changes in water quality in this area to some extent,and indicated the typical type of pollution caused by cultural eutrophication,which began in the late 1990s. Cysts of Alexandrium mainly those of A. catenella and A. tamarense complex occurred frequently and abundantly in this area,with the highest concentration and relative frequency of 503cysts/g D Wt and 12.0%respectively. Thus,high concentrations of Alexandrium cysts provided rich“seed bed”for Alexandrium blooms and an important resource of PSP toxin especially in winter.

关 键 词：大亚湾 沉积物 甲藻孢囊 亚历山大藻 浮游生物 

分 类 号：Q914.82[天文地球—古生物学与地层学] X55[生物学—古生物学]