Phytoplankton pigment and absorption characteristics along meridional transects in the Atlantic Ocean
Phytoplankton pigment and absorption characteristics along meridional transects in the Atlantic Ocean
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DOI：
10.1016/s0967-0637(01)00081-4
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发表时间：
2002-04-01
影响因子：
2.4
通讯作者：
Hooker, S
中科院分区：
文献类型：
--
作者：
Barlow, RG;Aiken, J;Hooker, S
研究了英国和福克兰群岛之间以及南非和英国之间沿大西洋两个经向断面的真光区浮游植物的色素模式和相关的吸收特性。总叶绿素a(TChla=MVChla+DVChla+Chellide a)浓度和硅藻(岩藻黄质)、纳米鞭毛藻和蓝藻(玉米黄质)的生物标志物色素在温和的东北大西洋和北部少营养环带的春季和秋季似乎具有相似的分布模式。二乙烯基叶绿素a水平(原叶绿素植物)在春季低营养环流的深叶绿素最大处较高，然而，在非洲西北部上升流区观察到显著的季节差异。春季，TChla在上层混合层中的浓度是后者的两倍，群落以硅藻和裸子植物(19‘-己酰氧岩藻黄质)为主。秋季以层状结构为主，上层水柱中有蓝藻、硅藻和裸藻，次表层为硅藻和混合纳米鞭毛虫。在南大西洋，本格拉上升流生态系统和巴西-福克兰海流交汇带(BFCCZ)是生产力最高的区域，本格拉的TChla水平是本格拉的两倍。硅藻在本格拉系统中占主导地位，而纳米鞭毛虫是BFCCZ中最普遍的类群。色素浓度沿南部少营养回的东部边界较大，并分布在较浅的深度。较深的叶绿素峰值是西部边界富营养化水域的一个特征，蓝藻在两个断面的上层水柱中占主导地位，在叶绿素峰值处有一群混合的纳米鞭毛虫。根据色素数据重建的光谱估计了吸收系数。尽管TChla在生产区的吸收较大，但TChla的特异性系数在营养贫乏的地区较高。在以硅藻或纳米鞭毛虫为主的群落中，色素吸收总体上随深度和光照的减弱而均匀，在440 nm处以Tchla为主要吸收色素，在490 nm处以光合类胡萝卜素(PSC)为主。叶绿素c和光保护类胡萝卜素(PPC)的吸收较低。蓝藻普遍存在的种群具有高PPC吸收的特征，特别是在490 nm处，遍及大部分真光区。这些数据表明，色素对浮游植物吸收的变异性的影响主要是由于PPC吸收的变化。(C)2002爱思唯尔科学有限公司。保留所有权利。
Pigment patterns and associated absorption properties of phytoplankton were investigated in the euphotic zone along two meridional transects in the Atlantic Ocean, between the UK and the Falkland Islands, and between South Africa and the UK. Total chlorophyll a (TChla = MVChla + DVChla + chlorophyllide a) concentrations and the biomarker pigments for diatoms (fucoxanthin), nanoflagellates and cyanobacteria (zeaxanthin) appeared to have similar distribution patterns in the spring and in the autumn in the temperate NE Atlantic and the northern oligotrophic gyre. Divinyl chlorophyll a levels (prochlorophytes) were greater in spring at the deep chlorophyll maximum in the oligotrophic gyre, however, Marked seasonal differences were observed in the NW African upwelling region. TChla concentrations were twice as high in the upper mixed layer in the spring, with the community dominated by diatoms and prymnesiophytes (19'-hexanoyloxyfucoxanthin). A layered structure was prevalent in the autumn where cyanobacteria, diatoms and prymnesiophytes were located in the upper water column and diatoms and mixed nanoflagellates at the sub-surface maximum. In the South Atlantic, the Benguela upwelling ecosystem and the Brazil-Falklands Current Confluence Zone (BFCCZ) were the most productive regions with the TChla levels being twice as high in the Benguela. Diatoms dominated the Benguela system, while nanoflagellates were the most ubiquitous group in the BFCCZ. Pigment concentrations were greater along the eastern boundary of the southern oligotrophic gyre and distributed at shallower depths. Deep chlorophyll maxima were a feature of the western boundary oligotrophic waters, and cyanobacteria tended to dominate the upper water column along both transects with a mixed group of nanoflagellates at the chlorophyll maximum.Absorption coefficients were estimated from spectra reconstructed from pigment data. Although absorption was greater in the productive areas, the TChla-specific coefficients were higher in oligotrophic regions. In communities that were dominated by diatoms or nanoflagellates, pigment absorption was generally uniform with depth and attenuating irradiance, with TChla being the major absorbing pigment at 440 nm and photosynthetic carotenoids (PSC) at 490 nm. Absorption by chlorophyll c and photoprotective carotenoids (PPC) was much lower. Populations where cyanobacteria were prevalent were characterized by high PPC absorption, particularly at 490 nm, throughout most of the euphotic zone. The data suggested that the effect of pigments on the variability of phytoplankton absorption was due primarily to the variations in absorption by PPC. (C) 2002 Elsevier Science Ltd. All rights reserved.