导　　师： 王朝晖

学科专业： 071004

授予学位： 硕士

作　　者： ;

机构地区： 暨南大学

摘　　要： 于2007年4月～2008年3月,对大鹏湾盐田港、大亚湾大鹏澳海域浮游植物休眠体分布状况及环境因子进行了周年调查,分析了沉积物中浮游植物休眠体的组成,并对沉积物样品在25℃下进行了实验室萌发研究,观察了20 d和40 d的萌发状况。同时于2005年4～5月,在长江口外及浙江中南部海域赤潮高发区采集了15～40 cm的沉积物柱状样,分层研究了甲藻孢囊的垂直分布。目的在于揭示浮游植物休眠体对海洋浮游植物生态群落的影响,弗赤潮发生机制提供科学依据。 通过对南海典型海域沉积物中浮游植物休眠体的调查,共鉴定出浮游植物休眠体83种隶属于47个属,其中甲藻孢囊51种,硅藻休眠体/(包括休眠孢子和休眠细胞29种。通过周年表层沉积物的培养,共萌发出浮游植物营养细胞97种/(含变种、变型/),其中硅藻门50种,甲藻门35种,其它种类浮游植物营养细胞如定鞭藻、蓝藻、绿藻、硅鞭藻等有12种。 在萌发的浮游植物和休眠体中,锥状斯氏藻、亚历山大藻、旋沟藻是常见的有毒有害藻类,而Hetereocapsa.spp、环沟藻、巴哈马梨甲藻、牡蛎甲藻、金色藻等有毒藻类在本次调查的出现,表明这些有毒有害藻类具有形成赤潮的潜力。各站位浮游植物休眠体细胞丰度在217.1～6764.2 cells//cm~3,总平均值为1337.9cells//cm~3。萌发出的营养细胞丰度在0～470660.6 cells//cm~3,两海域20 d和40 d萌发出的营养细胞平均丰度分别为16331.0、17438.1 cells//cm~3。总的来说大亚湾海域沉积物中休眠体及其萌发的营养细胞/(尤其是甲藻/)种类和丰度多于大鹏湾海域。 长江口及其南部海域甲藻孢囊种类十分丰富,本研究中共鉴定出46种甲藻孢囊,其中自养型19种,异养型27种。由于长江口复杂的流系结构、高强度的人为干扰以及高的沉积速率,致该海域孢囊丰度较低,平均丰度为366.2 cysts·g~/(-1/),同时垂直分布特征不明显,而在远离长江口的浙江南部海域受长江口影响较小,沉积物中甲藻孢囊丰度较高。锥状斯氏藻孢囊是最为丰富的自养型甲藻孢囊,异养型甲藻孢囊以原多甲藻属为主,其它类型孢囊仅零星分布。有毒藻亚历山大藻孢囊在各站位均有分布,但丰度较低,最高值仅为68.1 cysts·g~/(-1/)。 Annual survey of phytoplankton resting spore in surface sediments and environmental factors was carried out in Daypeng Bay and Daya Bay,from April 2007 to March 2008.Sieved sediments between 20 and 125μm were incubated at 25℃for 20 d and 40 d.Five sediment cores about 15～40 cm in length were collected from the Changjiang River Estuary and adjacent waters in April and May 2005 to investigate the vertical distribution of dinoflagellate resting cysts.The purpose of this study is to understand the effects of resting spore on phytoplankton community,and to provide basic data for the mechanism of HAB Occurrence. A total of 83 types belonging to 47 genera of resting spores were identified during the annual survey of surface sediments from Dapeng Bay and Daya Bay. Fify-one dinoflagellate cysts were observed,and 29 types diatom resting spore or resting cell were analyzed.97 phytoplankton taxa/(including speicies and varieties/) were identified in germinated phytoplankton,including 50 diatom species,35 dinoflagellate species and other 12 ones. Scrippsiella trochoidea,Alexandrium.spp,Cochlodinium.spp were main HAB species in germinated phytoplankton and resting spore.Other species such as Hetereocapsa.spp,Pyrodinium bahamense,Gyrodinium.sp,Ostreopsis lenticularis were observed in both sea areas,indicating the potential of harmful algal blooms of these species.The density of resting spore ranged from 217.1 cells//cm~3 to 6764.2 cells//cm~3,with an average of 1337.9 cells//cm~3.The cell number of germinated phytoplankton was from 0 cells//cm~3 to 470660.6 cells//cm~3 with averages of 16331.0 cells//cm~3 and 17438.1 cells//cm~3 respectively after 20 d and 40 d inoculation.The diversity and abundance of resting spore and germinated phytoplankton were generally higher in Daya Bay than those in Dapeng Bay. Rich diversity of dinocyst was observed in sediments from the Changjiang estuary and adjacent waters.46 different cyst morphotypes,representing 15 genera and 6 groups,were identified in this study.There were 19 autotrophic species and 27 heterotrophic ones.The results showed that the distribution of cyst was greatly influenced by complicated current system and environmental aspects in Changjiang estuary.Cyst abundance was low,with an average of 366.2 cysts·g~/(-1/),and no regular pattern was observed in vertical profiles of cyst distribution in all sampling stations. Cyst species richness in Zhoushan Island area was higher than other sampling stations. Cyst of Scrippsiella trochoidea dominated in autotrophic cyst assemblages,with the average percentages from 17.0/%to 28.9/%.Cysts in genus Protoperidinium were predominant in heterotrophic group with average percentages ranging from 29.5/%to 53.6/%.Cysts of Alexandrium.spp distributed widely in all stations,but the abundance was low,with the maximum concentration of 68.1 cysts·g~/(-1/).

关 键 词： 浮游植物休眠体 甲藻孢囊 环境因子 大亚湾 大鹏湾 长江口

分 类 号： [X55]

领　　域： [环境科学与工程]