大亚湾浮游植物粒级结构和种类组成对淡澳河河口水加富的响应  

Phytoplankton responses to Dan’ao River estuary water enrichment in terms of size structure and community composition

作　　者：向晨晖 刘甲星 柯志新[1] 周林滨[1] 谭烨辉[1,2,3,4] XIANG Chenhui;LIU Jiaxing;KE Zhixin;ZHOU Linbin;TAN Yehui(Key Laboratory of Tropical Marine Bio-resources and Ecology,Guangdong Provincial Key Laboratory of Applied Marine Biology,South China Sea Institute of Oceanology,Chinese Academy of Sciences,Guangzhou 510301,China;University of Chinese Academy of Sciences,Beijing 100049,China;Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou),Guangzhou 510301,China;Innovation Academy of South China Sea Ecology and Environmental Engineering,Chinese Academy of Sciences,Guangzhou,510301,China)

机构地区：[1]中国科学院南海海洋研究所,热带海洋生物资源与生态重点实验室,广东省应用海洋生物学重点实验室,广东广州510301 [2]中国科学院大学,北京100049 [3]南方海洋科学与工程广东省实验室,广东广州510301 [4]中国科学院南海生态环境工程创新研究院,广东广州510301

出　　处：《热带海洋学报》2021年第2期49-60,共12页Journal of Tropical Oceanography

基　　金：国家自然科学基金(31971432,41506161);南方海洋科学与工程广东省实验室(广州)项目(GML2019ZD0405);广东省海洋经济发展项目(GDOE[2019]A32);广东省省级科技计划项目(2017B0303014052);中国科学院南海生态环境工程创新研究院自主部署项目(ISEE2018PY01)。

摘　　要：人类活动引起的营养物质输入导致大亚湾出现海水富营养化、赤潮频发和生物多样性下降等生态问题。为探究陆源输入影响下大亚湾湾顶淡澳河输入对湾内浮游植物粒级结构和种类组成的影响,2016年10月在大亚湾进行了原位观测和培养试验。原位观测结果显示,淡澳河口的总溶解态氮、磷浓度分别达到85.3mmol·L^(-1)和1.5mmol·L^(-1)。加富培养试验结果表明,淡澳河河口水加富对总叶绿素a(Chl a)和总浮游植物丰度有显著促进作用,并导致浮游植物粒级结构由小粒级Chl a(0.7~20μm)占主导;浮游植物丰度中甲藻比例升高,主要种类为锥状斯氏藻(Scrippsiella trochoidea)和原甲藻(Prorocentrum spp.)。同样,尿素加富也促进了浮游植物群落中小粒级Chl a和甲藻的比例增加,且主要甲藻种类与河口水加富结果一致。无机氮、磷同时加富促进了总Chl a和浮游植物总丰度增加,而对浮游植物粒级结构和甲藻丰度则没有明显影响。对照河口水和氮、磷营养盐加富试验结果,说明河口水携带的溶解性有机氮源可能是导致大亚湾浮游植物群落小型化,促进甲藻生长的关键营养盐形态,其携带的无机氮、磷同时促进总浮游植物丰度增加。本研究结果表明有机形态营养组分对大亚湾富营养化和有害藻华可能产生重要影响。Daya Bay is experiencing ecological problems such as eutrophication and frequent algal bloom under the pressure of intense anthropogenic activities.The Dan’ao River is the largest rive entering Daya Bay.We found the concentrations of total dissolved nitrogen and phosphorus at the Dan’ao River estuary reached 85.3 and 1.5mmol·L^(-1),respectively.In situ enrichment experiments were conducted to explore the effect of estuary water from the Dan’ao River on phytoplankton community.Our results showed filtered water(0.2μm)from the Dan’ao River estuary promoted total Chlorophyll a(Chl a)and phytoplankton abundance,and shifted the dominated Chl a size structure to smaller size(0.7~20μm),and also increased the relative abundance of dinoflagellates(Scrippsiella trochoidea and Prorocentrum spp.).The phytoplankton size structure and species composition changed in the same pattern under the addition of dissolved organic nitrogen(DON)of urea.Although combined addition of dissolved inorganic nitrogen and phosphorus increased total Chl a and abundance,the phytoplankton size structure and dinoflagellate abundance did not show significant changes.Our results demonstrate that DON may be the causative nutrient component that leads to miniaturization of the phytoplankton community and promotes the growth of dinoflagellate by comparing the enrichment results of estuary water to N and P nutrient enrichments.These results indicate the significance of DON for eutrophication and harmful algal blooms in Daya Bay,which should be included in management strategies of coastal water eutrophication.

关 键 词：大亚湾 淡澳河 尿素 浮游植物群落 

分 类 号：P735.121[天文地球—海洋生物学]