华南沿海典型海域甲藻孢囊地理分布及环境指示作用研究

发布时间：2018-02-10 08:33

本文关键词： 华南沿海甲藻孢囊富营养化生物地理分布环境指示赤潮　出处：《暨南大学》2017年博士论文　论文类型：学位论文

【摘要】：甲藻孢囊是甲藻失去鞭毛和游泳能力后,所形成的不动细胞。孢囊形成后会加厚细胞壁沉积于沉积物之中,进入甲藻生活史中特殊的休眠阶段。甲藻孢囊被认为是赤潮发生的种源,也是有毒有害甲藻全球扩散的载体。孢囊具有孢粉质壁,可在海洋沉积物中长时间保存,是海洋沉积物中重要的微化石群。沉积物中的孢囊可反映海洋环境变化历程,为追溯海区人类活动的影响以及海洋环境的变化提供有效信号。本研究在华南沿海的17个海域设置了94个采样点,其中包括广东沿海的柘林湾、汕头港、碣石湾、红海湾、大亚湾、大鹏湾、桂山岛、海陵湾、水东港、雷州湾和流沙湾海域,广西沿海的防城港和北海港海域,海南西北部沿海的海口港、马村港、洋浦港和八所港海域。采集了表层沉积物样品,对甲藻孢囊进行了定性定量研究,较为全面揭示了甲藻孢囊在华南沿海的地理分布状况,丰富了华南沿海甲藻孢囊地理分布信息;并通过查阅文献资料,绘制了甲藻孢囊在我国沿海的地理分布图;利用多种统计分析软件,研究了孢囊与海域富营养化、重金属污染以及赤潮发生的关系,揭示了孢囊对海洋环境的指示作用;采集了柘林湾186 cm柱状沉积物样品,通过孢囊的垂直分布以及生源要素、金属元素及沉积速率分析,揭示了近50年来柘林湾的环境变化,明晰了沉积物中孢囊集群对环境变化的响应。本研究揭示了甲藻孢囊对海洋环境的响应及其指示作用,研究结果对华南沿海生物多样性和海洋环境保护以及海洋资源的可持续利用提供了科学依据,研究结果显示如下:(1)在华南沿海17个典型海域94个表层沉积物中共鉴定甲藻孢囊34种,其中自养型甲藻孢囊12种,异养型甲藻孢囊22种;对34种甲藻孢囊进行了分类学研究,并建立了孢囊图谱,丰富了华南沿海甲藻孢囊的多样性,为今后孢囊研究提供了基础资料。(2)根据本调查结果及资料收集,绘制了34种孢囊在中国沿海的地理分布图,填补了甲藻孢囊在我国沿海分布信息。结果显示锥状斯氏藻是我国沿海最为常见的孢囊类型,有毒有害赤潮原因种塔玛亚历山大藻和链状裸甲藻的孢囊分布广泛,需要防范其赤潮的发生。珠江口海域和北海港为有毒有害赤潮原因种的孢囊密度高值区,而且沉积物中的孢囊多是未萌发的活孢囊,具有赤潮爆发的潜在可能。(3)近岸海域较高的沉积物粒径以及航道、港口、养殖活动所引起的水体扰动使孢囊密度较低,广东沿海表层沉积物中甲藻孢囊密度介于14-250 cysts/g D Wt之间,平均密度为69 cysts/g D Wt;广西沿海孢囊密度为70-571 cysts/g D Wt之间,平均密度为249 cysts/g D Wt;海南西北沿海孢囊密度为34-375 cysts/g D Wt之间,平均为109 cysts/g D Wt。(4)异养型甲藻孢囊的百分比含量较高,其中广东、广西以及海南西北沿海海域平均分别为52.8%、43.9%和71.2%,较低的甲藻孢囊密度以及较高的异养型甲藻孢囊百分比含量是工业污染、富营养化以及港口水体扰动的标志。(5)冗余分析(RDA)表明,BSi和Cd是影响广东沿海孢囊分布的重要因素,0.7%和0.114 mg/kg是BSi和Cd对孢囊分布产生影响的拐点;TN对广西沿海孢囊分布影响明显,而盐度则对海南西北沿海孢囊分布影响较大,拐点值分别为0.15%和31.42。(6)IndVal指示种分析显示,锥状斯氏藻、膝沟藻和锥形原多甲藻是指示粤中海域富营养化的指示孢囊,锥形原多甲藻孢囊则可用来指示粤东海域金属污染状况;透镜翼甲藻是指示广西沿海TN含量和富营养化的指示孢囊。锥状斯氏藻孢囊可作为盐度、富营养化以及水环境变化的有效指示种,指示受到多种人为活动干扰的环境变化。(7)柘林湾柱状沉积物中异养型甲藻孢囊含量的上升反映了柘林湾的富营养化进程,异养型甲藻孢囊对金属污染的耐受性也较高,同时富营养化也导致硅藻生产力的下降。甲藻孢囊、生源要素以及金属元素的垂直分布与柘林湾经济发展密切相关,近50年来柘林湾的环境变化可分为3个时期:第一阶段为1985年之前,生源要素和孢囊通量较低,金属元素基本和背景值相同;第二阶段从1985年到2000年代早期,在此期间富营养化程度提高,孢囊产量上升,金属污染加剧,但是硅藻生产力有所下降;第三阶段是2000年之后,孢囊密度、TOC和TN迅速的增加,而金属含量下降,显示环境有所改善。研究结果表明,华南沿海表层沉积物中的甲藻孢囊组成与分布可以反映不同人为活动所带来的水体富营养过程及环境变化历程,是指示海洋环境变化有效的生物学指标。
[Abstract]:Dinoflagellate cysts are losing dinoflagellate flagella and swimming ability, fixed cells formed. Cyst formation after thickened cell wall deposition in sediments, special dormancy stage into the dinoflagellate. Dinoflagellate cysts are believed to be the source of a red tide, is toxic and harmful dinoflagellate carrier the global spread of the cyst wall. With sporopollenin, preserved in marine sediments in the long time, is important in marine sediment micro fossils in sediments. The cysts can reflect the change of marine environment process, provide effective signal for the influence of human activities in the back as well as the change of the marine environment. In this study, 17 the coastal waters of Southern China set 94 sampling points, including Guangdong coastal Zhelin Bay, Shantou harbor, red bay, Dayawan Jieshi Bay, Dapeng Bay, Guishan Island, Hailing Bay, Donggang water, Leizhou Bay and Liusha Bay, Guangxi coastal Fangchenggang And the North Harbour sea, northwest of Hainan along the coast of Haikou port, Macun port, Yangpu Port and eight port waters. Surface sediment samples were collected, the dinoflagellate cysts were qualitatively and quantitatively studied, comprehensively reveal the dinoflagellate cysts in the geographical distribution of the coastal areas of Southern China, Southern China rich coastal dinoflagellate sac geographic distribution information; and through access to literature, drawing the dinoflagellate cysts in the geographical distribution of China's coastal map; using a variety of statistical analysis software, the cyst and the eutrophication, the relationship between heavy metal pollution and red tide, revealing the indication of cyst of the marine environment were collected; Zhelin Bay 186 cm sediment, the vertical distribution of elements of cyst and source analysis of metal elements and deposition rate, reveals the change of Zhelin Bay environment in recent 50 years, clear sediment cyst in the cluster to environmental change Response. This study reveals the dinoflagellate cyst response and its indication to the marine environment, the research results of Southern China coastal biological diversity and protection of the marine environment and the sustainable utilization of marine resources to provide a scientific basis, the research results are as follows: (1) in the 17 typical areas of Southern China 94 coastal surface sediments of the identification of a 34 kinds of algal cysts, the autotrophic dinoflagellate cysts 12, heterotrophic dinoflagellate cysts and 22 species; 34 kinds of dinoflagellate cysts of taxonomic research and the establishment of a cyst of rich diversity of Southern China coastal dinoflagellate cysts, and provide basic information for future cyst study. (2) according to the results of the survey and data collection, drawing 34 cysts in the geographical distribution of China coastal map, fill the dinoflagellate cysts in China's coastal distribution information. The results showed that s.trochoidea cysts are the most common type of China's coastal, toxic The reason for cyst distribution of red tide algae and Tamar Alexander Gymnodinium catenatum widely, the need to prevent the occurrence of red tide. The cyst density in the Pearl River Estuary and North Harbour for the poisonous and harmful red tide reason of the high value area, and the sediment in the cyst is not germination of live cyst, have the potential of red tide the outbreak. (3) in coastal waters of high sediment grain size, waterway, port, aquaculture activities caused by water disturbance makes the cyst density lower, between in the surface sediments of Guangdong coastal dinoflagellate cyst density ranged from 14-250 cysts/g D Wt, the average density is 69 cysts/g D Wt; Guangxi coastal cyst density 70-571 cysts/g D Wt, the average density is 249 cysts/g D Wt; Hainan northwest coastal cyst density is between 34-375 and cysts/g D Wt, an average of 109 cysts/g D Wt. (4) percentage of heterotrophic dinoflagellate cysts is higher, including Guangdong, Guangzhou West and northwest of Hainan coastal waters on average were 52.8%, 43.9% and 71.2%, lower dinoflagellate cyst density and higher heterotrophic dinoflagellate cysts is the percentage of industrial pollution, eutrophication and port water disturbance sign. (5) redundancy analysis (RDA) showed that BSi and Cd are important Guangdong coastal cyst distribution, 0.7% and 0.114 mg/kg BSi and Cd on the distribution of the influence of the inflection point of cyst; TN obvious influence on Guangxi coastal cyst distribution, while the salinity of Hainan northwest coastal cyst distribution has great effect, the inflection point is respectively 0.15% and 31.42. (6) IndVal indicator species analysis showed that s.trochoidea, gonyautoxins and conical original PERIDINIUM is indicative of Guangdong in eutrophication indication of the cyst, the cone of dinoflagellate cysts can be used to indicate the metal pollution in the eastern sea area; the lens is indicative of dinoflagellate wing of Guangxi coastal eutrophication and TN content The indication of cyst. S.trochoidea cysts can be used as a valid indicator of salinity, eutrophication and water environment change, indicating interference by a variety of anthropogenic environmental change. (7) the rising content of heterotrophic dinoflagellate cysts in Zhelin Bay sediments reflect the eutrophication process in Zhelin Bay the heterotrophic dinoflagellate cysts tolerance to metal contamination is higher, while eutrophication also led to decline in diatom productivity. Dinoflagellate cysts, closely related to the vertical distribution of biogenic elements and metal elements and Zhelin Bay economic development, nearly 50 years of environmental change in Zhelin Bay can be divided into 3 the first stage is the period: before 1985, biogenic elements and cyst flux is low, and the same basic metal element background value; the second stage is from 1985 to early 2000s, during which the eutrophication degree increased, cyst production increased, metal pollution, but silicon Algal productivity declined; the third stage is after 2000, the cyst density, TOC and TN increased rapidly, and the metal content decreased, the display environment has improved. The results show that the composition of dinoflagellate cysts in surface sediments of coastal Southern China and distribution of environmental changes the water eutrophication process reflects the people brought to activities and course, is indicative of biological indicators of changes in the marine environment effectively.

【学位授予单位】：暨南大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：X55

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