Ecological divergence of a mesocosm in an eastern boundary upwelling system assessed with multi-marker environmental DNA metabarcoding
Ecological divergence of a mesocosm in an eastern boundary upwelling system assessed with multi-marker environmental DNA metabarcoding
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DOI：
10.5194/bg-20-1277-2023
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发表时间：
2023-04
期刊：
影响因子：
4.9
通讯作者：
Markus A. Min;D. Needham;S. Sudek;Nathan K. Truelove;Kathleen J. Pitz;Gabriela Chávez;Camille Poirier;B. Gardeler;Elisabeth von der Esch;A. Ludwig;U. Riebesell;A. Worden;F. Chavez
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文献类型：
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作者：
Markus A. Min;D. Needham;S. Sudek;Nathan K. Truelove;Kathleen J. Pitz;Gabriela Chávez;Camille Poirier;B. Gardeler;Elisabeth von der Esch;A. Ludwig;U. Riebesell;A. Worden;F. Chavez
抽象的。东部边界上升流系统（EBUS）贡献了不成比例的一部分，相对于其规模的全球渔获量，特别容易受到全球环境变化。在这里，我们提出了超过50天的社区在原地围隔6公里离岸的卡劳，秘鲁，并在附近的未封闭的沿海太平洋的演变。利用多标记环境DNA（eDNA）元条形码和流式细胞术监测的社区。从每周水样中提取的DNA进行扩增子测序的四个遗传位点：（1）光合真核生物16 SrRNA基因的V1-V2区（2）18 S rRNA基因的V9区，用于探索真核生物，但以浮游植物为目标;（3）细胞色素氧化酶I（COI），用于探索真核生物分类群，但以无脊椎动物为目标;（4）靶向脊椎动物的12 SrRNA基因。多标记方法显示了围隔生态系统和开放海洋之间的群落差异（从微生物到鱼类）。与环境信息一起，遗传数据进一步促进了我们对在不断变化的海洋中塑造EBUS社区的过程的机械理解。在50天的实验过程中，未封闭的海洋经历了显着的变化，群落组成发生了时间变化，但仍然由高营养物上升流条件特征的生物（例如，硅藻，桡足类，硅藻）。一个大的方向变化，发现在围隔群落。当上升流松弛和沃茨分层时，发展起来的中型生态系统群落具有上升流区域的特征（例如，腰鞭毛虫、纳米鞭毛虫）。在围隔中盐度驱动的实验分层条件下，以及沿海厄尔尼诺带来的温暖条件下，甲藻的选择可能是EBUS如何应对全球环境变化的指示（即，地表温度和淡水输入的增加，导致分层增加）。
Abstract. Eastern boundary upwelling systems (EBUS) contribute a disproportionate fraction of the global fish catch relative to their size and are especially susceptible to global environmental change. Here we present the evolution of communities over 50 d in an in situ mesocosm 6 km offshore of Callao, Peru, and in the nearby unenclosed coastal Pacific Ocean. The communities were monitored using multi-marker environmental DNA (eDNA) metabarcoding and flow cytometry. DNA extracted from weekly water samples were subjected to amplicon sequencing for four genetic loci: (1) the V1–V2 region of the 16S rRNA gene for photosynthetic eukaryotes (via their chloroplasts) and bacteria; (2) the V9 region of the 18S rRNA gene for exploration of eukaryotes but targeting phytoplankton; (3) cytochrome oxidase I (COI) for exploration of eukaryotic taxa but targeting invertebrates; and (4) the 12S rRNA gene, targeting vertebrates. The multi-marker approach showed a divergence of communities (from microbes to fish) between the mesocosm and the unenclosed ocean. Together with the environmental information, the genetic data furthered our mechanistic understanding of the processes that are shaping EBUS communities in a changing ocean. The unenclosed ocean experienced significant variability over the course of the 50 d experiment, with temporal shifts in community composition, but remained dominated by organisms that are characteristic of high-nutrient upwelling conditions (e.g., diatoms, copepods, anchovies). A large directional change was found in the mesocosm community. The mesocosm community that developed was characteristic of upwelling regions when upwelling relaxes and waters stratify (e.g., dinoflagellates, nanoflagellates). The selection of dinoflagellates under the salinity-driven experimentally stratified conditions in the mesocosm, as well as the warm conditions brought about by the coastal El Niño, may be an indication of how EBUS will respond under the global environmental changes (i.e., increases in surface temperature and freshwater input, leading to increased stratification) forecast by the IPCC.