Long-Term Change in Copepod Community Structure in the Western Antarctic Peninsula: Linkage to Climate and Implications for Carbon Cycling
Long-Term Change in Copepod Community Structure in the Western Antarctic Peninsula: Linkage to Climate and Implications for Carbon Cycling
复制标题
南极半岛西部桡足类群落结构的长期变化：与气候的联系以及对碳循环的影响
DOI：
10.25773/v5-we5s-aq55
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发表时间：
2014
影响因子：
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通讯作者：
Miram R. Gleiber
中科院分区：
文献类型：
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作者：
Miram R. Gleiber
桡足类是南大洋的主要中浮游动物，但其丰度和分布在经历快速气候变暖的西南极半岛(WAP)的长期变化尚不清楚。桡足类也是WAP中潜在的重要浮游植物食草动物，并通过生产下沉的粪便颗粒为碳出口做出贡献。我研究了20年来(1993-2013年)夏季(1月至2月)WAP沿线的桡足类群落结构和丰度，并调查了桡足类丰度的长期趋势及其与环境参数(海冰、浮游植物生物量和生产力、气候指数和海表面温度)的关系。桡足类平均占WAP中浮游动物总丰度的81%；桡足类群落由少数物种主导，包括Metridia gerlachei、Oithona spp.和Calanoides acutus。随着时间的推移，桡足类总丰度有显著的长期增加，丰度较高的年份海冰较早消退，浮游植物生物量和生产力较高。个别物种的趋势反映了摄食和生活史策略，但总体上遵循了整个桡足类的趋势。为了研究桡足类放牧对浮游植物的影响和对碳输出的贡献，我在2012-2014年的每年1月对WAP的大型优势桡足动物(Calanus Propuus、Rhincalanus gias和C.acutus)进行了放牧和粪便颗粒生产实验。桡足类对放牧浮游植物生物量(1%)和生产力(1%，最高可达11%)的总体影响较小。除了浮游植物外，桡足类可能还以其他碳源(即原生动物和后生动物)为食，以满足新陈代谢需求，特别是在近海、斜坡地区和低叶绿素a条件下。粪便颗粒产出率(排泄率)较高，为0.82~37.3pC ind。D a y 1(南极洲副南极)，没有显示出区域趋势。我的结果表明，导致夏季桡足类丰度年际变化和WAP放牧的机制可以用来预测桡足类将如何对未来的环境变化做出反应，并可能影响碳在食物网中的流动和碳向深处的输出。弗吉尼亚州威廉与玛丽学院海洋科学米拉姆·雷泽尔·格莱伯学院
Copepods are the dominant mesozooplankton in the Southern Ocean, but long term change in their abundance and distribution along the Western Antarctic Peninsula (WAP), a region experiencing rapid climate warming, is unknown. Copepods are also potentially important grazers of phytoplankton in the WAP and contributors to carbon export through production of sinking fecal pellets. I examined summer (JanuaryFebruary) copepod community structure and abundance along the WAP over two decades (1993-2013) and investigated long-term trends in copepod abundance and their relationship with environmental parameters (sea ice, phytoplankton biomass and productivity, climate indices, and sea surface temperature). Copepods comprised on average 81% of total mesozooplankton abundance in the WAP; the copepod community was dominated by a few species that included Metridia gerlachei, Oithona spp., and Calanoides acutus. There was a significant long-term increase in total copepod abundance over time, with higher abundances in years with earlier sea ice retreat and higher phytoplankton biomass and productivity. Trends for individual species reflected feeding and life cycle strategies, but generally followed those of total copepods. To examine the impact of copepod grazing on phytoplankton and contribution to carbon export, I conducted grazing and fecal pellet production experiments with the large dominant copepods (Calanus propinquus, Rhincalanus gigas, and C. acutus) in the WAP each January from 2012 to 2014. Copepods have a low overall impact on grazing of phytoplankton biomass (<1%) and productivity (1%, up to 11%). Copepods were likely feeding on other sources of carbon (i.e., protozoans and metazoans) besides phytoplankton to meet metabolic demands, especially in the offshore, slope region and in low chlorophyll a conditions. Fecal pellet production (egestion) rates were high, ranging from 0.82 (R. gigas) to 37.3_pC ind. d a y 1 (Paraeuchaeta antarctica), and did not exhibit regional trends. My results suggest mechanisms leading to interannual variability of summer copepod abundance and grazing in the WAP can be used to predict how copepods will respond to future environmental changes and may affect the flow of carbon through the food web and the export of carbon to depth. Miram Rayzel Gleiber SCHOOL OF MARINE SCIENCE THE COLLEGE OF WILLIAM AND MARY IN VIRGINIA