Chemotaxonomy-based mapping of phytoplankton communities in the subtropical Southwestern Atlantic Ocean, with emphasis on the marine cyanobacterium Trichodesmium
Chemotaxonomy-based mapping of phytoplankton communities in the subtropical Southwestern Atlantic Ocean, with emphasis on the marine cyanobacterium Trichodesmium
复制标题
基于化学分类学的亚热带西南大西洋浮游植物群落绘图，重点关注海洋蓝藻 Trichodesmium
DOI：
10.1016/j.pocean.2019.01.008
复制
发表时间：
2019
影响因子：
4.1
通讯作者：
E. Secchi
中科院分区：
文献类型：
--
作者：
Camila Rodrigues Lima;C. R. Mendes;V. Tavano;A. Detoni;E. Secchi
通过化学分类学分析(HPLC-CHEMTAX)对巴西西南部大陆架和陆坡浮游植物群落的组成和分布进行了评价。这些样本是在2012年至2014年春秋两季的五次海洋巡航中采集的。在实地调查期间，共记录到14次毛藻(光面)的表面水华。通过色素分析和显微镜计数两种方法估计了毛霉菌的生物量，除了一些浮油外，两种方法之间存在显著的相关性。然而，通常在CHEMTAX中使用的毛霉色素生物标志物--粘黄叶素只在毛霉菌监测站的7个样品中检测到，这表明它们在色素化学分类方法中的使用应该谨慎，因为它可能导致毛霉菌生物量的估计错误。表层有4个水团：羽状水(PPW)、亚热带陆架水(STSW)、陆架水(SW)和热带水(TW)。已识别的水团似乎是影响研究区浮游植物种群组成、分布和生物量的主要驱动因素。与巴西海流有关的盐暖少营养型TW是秋季和春季的主要表层水团。这项工作中的地表水一般都与总叶绿素(TChla)和营养盐浓度的低值有关。在无浮冰条件下，几乎所有海洋站的表层TChlac浓度都很低，范围为0.04~2.44 mg m−3(平均为0.27 mg m−3)。受PPW和STSW影响的站点生物量密度最高。总体而言，浮游植物群落以原氯球菌、半枝藻、聚球藻和毛霉菌为主，它们对春季和秋季浮游植物的贡献率均在70%以上。其他浮游植物类群(原生植物、隐藻和甲藻)所占比例较小，占总生物量的15%以下。典型对应分析表明，原氯球菌、异形藻类、聚球藻和毛霉菌均与TW和Sw有关，与水柱稳定性较差、混合层较深、温度和盐度呈正相关。隐藻、甲藻、原藻类和硅藻主要与STSW和PPW相关，与较高的稳定性和营养物质(氮和磷)呈正相关，与温度和盐度呈负相关。我们的结果表明，色素分析(HPLC-CHEMTAX)可以对巴西南部和东南部大陆架和陆架断裂的浮游植物群落的分布进行详细的绘制，目前用这种方法估计的毛状藻生物量应该仔细修订。
The composition and distribution of the phytoplankton community on the southweastern Brazilian continental shelf and continental slope were evaluated through chemotaxonomic analyses (HPLC-CHEMTAX). The samples were collected during five oceanographic cruises from 2012 to 2014 in spring and autumn. Fourteen surface blooms ofTrichodesmium(slicks) were registered during the field surveys. TheTrichodesmiumbiomass was estimated by both pigment analyses and microscope counts, with significant correlation found between the methods, except in some slicks. However, myxoxanthophyll, aTrichodesmiumpigment biomarker generally used in CHEMTAX, was detectable only in seven samples from stations withTrichodesmiumslicks, indicating that their use in pigment chemotaxonomic approaches should be taken with caution, because it could lead to errors in the estimation ofTrichodesmiumbiomass. Four water masses were identified at the surface: Plata Plume Water (PPW), Subtropical Shelf Water (STSW), Shelf Water (SW) and Tropical Water (TW). The identified water masses seem to be the main driving factor influencing the composition, distribution and biomass of phytoplankton groups in the study region. The salty-warm oligotrophic TW, associated with the Brazil Current, was the dominant surface water mass in both autumn and spring. The surface waters in this work were generally associated with low values of both total chlorophylla(TChla) and nutrient concentration. In no slicks conditions, surface TChlaconcentration was low ranging between 0.04 and 2.44 mg m−3(mean 0.27 mg m−3) in almost all oceanographic stations. The highest biomass concentrations were recorded in stations under influence of both PPW and STSW. Overall,Prochlorococcus,haptophytes,Synechococcus, andTrichodesmiumdominated the phytoplankton community and their contributions were above 70% to total Chlain both spring and autumn. The other phytoplankton groups (prasinophytes, cryptophytes and dinoflagellates) represented a minor fraction, with values below 15% of the total biomass. A Canonical Correspondence Analysis showed thatProchlorococcus, haptophytes,SynechococcusandTrichodesmiumwere related with both TW and SW and were also positively associated with weaker water column stability, a deeper mixed layer, temperature and salinity. In turn, cryptophytes, dinoflagellates, prasynophytes and diatoms, mainly associated with STSW and PPW, were positively correlated with higher stability and nutrients (nitrogen and phosphorus), and negatively associated with both temperature and salinity. Our results showed that the pigment analysis (HPLC-CHEMTAX) allowed a detailed mapping of phytoplankton communities' distribution in the south and southeastern Brazilian continental shelf and shelf-break, and that theTrichodesmiumbiomass, as currently estimated by this approach, should be carefully revised.
影响因子：
2.5
作者：
Hickman, A. E.;Dutkiewicz, S.;Follows, M. J.
通讯作者：
Follows, M. J.