| 摘要: |
| 报道了2001/2002年夏季南极普里兹湾邻近海域37个大面测站浮游植物的调查结果。经初步鉴定共有浮游植物3门37属86种, 其中硅藻在种类和细胞丰度上占绝对优势, 其次为甲藻。主要优势种为克格伦拟脆杆藻(Fragilariopsis kerguelensis)、细条伪菱形藻(Pseudo-nitzschia lineola)、短拟脆杆藻(Fragilariopsis curta)和赖氏束盒藻(Trichotoxon reinboldii)等南极特有种类和常见种类。调查区浮游植物分为两个群集, 分布在67°S以南的普里兹湾内的群集主要以克格伦拟脆杆藻、短拟脆杆藻、胡克星脐藻(Asteromphalus hookeri)和南极弯角藻(Eucampia antarctica)等南极特有种类和常见种类为主；分布在67°S以北的大洋海域的群集主要以细条伪菱形藻、赖氏束盒藻、拟膨胀伪菱形藻(Pseudo-nitzschia turgiduloides)和羽状环毛藻(Corethron pennatum)等南极常见种为主。调查区浮游植物的平均细胞丰度为(8796±29285)ind/L,细胞多分布于海水的表层,密集区分布在67°S以南的普里兹湾内, 浮游植物的细胞丰度同硝酸盐的浓度密切相关。调查区浮游植物的多样性程度是低的。
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| 关键词: 南极,普里兹湾及其邻近水域,浮游植物,群落结构,细胞丰度,多样性 |
| DOI：10.11693/hyhz200305007007 |
| 分类号: |
| 基金项目:国家自然科学基金资助项目,49876032号和40206020号 |
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| PHYTOPLANKTON IN THE PRYDZ BAY AND THE ADJACENT INDIAN SECTOR OF THE SOUTHERN OCEAN DURING THE AUSTRAL SUMMER 2001/2002 |
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SUN Jun1, LIU Dong-Yan1, NING Xiu-Ren2, LIU Cheng-Gang2
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1.Marine Life Science College, Ocean University of China;2.Second Institute of Oceanography, State Oceanic Administration
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| Abstract: |
| The investigation on Uterm?hl phytoplankton with samples from 37 grid stations in Prydz Bay and the adjacent Indian sector of the Southern Ocean during the austral summer 2001/2002 is reported in this paper. At each station, 500 ml water samples were taken from 0, 75 and 150 m depths, and preserved in neutral formalin solution of 2% final concentration formaldehyde. All samples were examined under invert microscope in the lab according to the Uterm?-hl method. 86 taxa belonging to 37 genera of 3 classes were identified, in which diatoms were predominant and coexisted with dinoflagellates and silicoflagellates. The dominant species were all diatoms, including Fragilariopsis kerguelensis, Pseudo-nitzschia lineola, Fragilariopsis curta and Trichotoxon reinboldii, etc., which were autochthonous and common species in Southern Ocean Waters. The predominant species was Fragilariopsis kerguelensis. Pseudo-nitzschia lineola was present at all stations, and Trichotoxon reinboldir was also almost present at all stations. These dominant species play an important role in marine ecosystem. The most common dinoflagellate species in the survey area were Amphidinium extensum and Protoperidinium bipes; they are small-celled phytoplanktons which were not easily detected in net samples. Although some species, such as Chaetoceros bulbuosus, Eucampia antarctica, Membraneis challengeri and Plagiotropis gaussii, were low in cell abundance, but they can be the indicator species of Antarctic Waters. Some diatom resting spores, dinoflagellate cyst and attachment bacteria in dead phytoplankton cells indicated that the phytoplankton community was in a decomposition phase of austral spring bloom. Another obvious feature of the phytoplankton community in the survey area was the predominance of big-celled or long-chained phytoplankton. This morphological feature was an ecological strategy of nutrient uptaking, preventing sinking and grazing. Two phytoplankton assemblages were distinguished by the Unweighted Pair Group Average Cluster Analysis; they were distributed in the Prydz Bay and high sea north to 67°S, respectively. The assemblage in the Prydz Bay was mainly composed of autochthonous and common Southern Ocean species, such as Fragilariopsis kerguelensis, Fragilariopsis curta, Asteromphalus hookeri and Eucampia antarctica. The
assemblage in the open sea north to 67°S was mainly composed of common Southern Ocean species, such as Pseudo-nitzschia lineola, Trichotoxon reinboldii, Pseudo-nitzschia turgiduloides and Corethron pennatum. The average values of Shannon-Wiener biological diversity index and Evenness index of phytoplankton community were 2.01±0.66 and 0.61±0.19, respectively. The Shonnon-Wiener index was high in the northwest part of the survey area. Compared to the other regions of the world oceans, the phytoplankton Shannon-Wiener biological diversity index and Evenness in survey area were low. The average phytoplankton cell abundance was 8796±29285 ind/L (n=94) ranged from 112 to 207274 ind/L. Diatom was 98.45% to total phytoplankton abundance. Cell abundance was high in surface layers at most stations, with subsurface maximum cell abundance at few stations. Box-Whisker figures showed that the dominant species were distributed in surface waters. In surface waters, high concentrations of phytoplankton cells were found in inner Prydz Bay. Pearson Correlate Analysis of phytoplankton cell abundance and environmental factors showed that phytoplankton abundance was negatively correlated to nitrate concentration, indicating that phytoplankton uptook nitrate and grew rapidly. The relative stable water column in Prydz Bay was the main reason for the fast growth of phytoplankton. The ecological
functions of key phytoplankton species in Antarctic Marine Ecosystem, such as Fragilariopsis kerguelensis, need further
study in the future.
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| Key words: Antarctic, Prydz Bay and its adjacent water, Phytoplankton, Community structures, Cell abundance, Biodiversity |
