Bentho-Pelagic Coupling on the West Antarctic Peninsula Shelf: The Impact and Fate of Bloom Material at the Seafloor

南极沿海水域的初级生产具有很强的季节性，向大陆架底部产生强烈的生物颗粒脉冲。这种季节性脉动可能对南极半岛西部大陆架的碳循环、底栖生态和物质埋藏产生重大影响。因此，我们提出了一个多学科的项目来评估海底积累、命运和底栖生物群落影响沿三个站点横跨南极大陆架在帕尔默LTER研究区。通过对我们的样带进行五次季节性巡航，我们将检验以下假设：(1)春季/夏季出口产品的很大一部分以植物碎屑或粪便颗粒的形式沉积在WAP架子上。(2)沉积的藻华产量是底栖生物长期（月）的活性颗粒有机碳来源。(3)底栖生物的取食和贮藏活动使大量不稳定的水华POC迅速俯冲到沉积物柱中。(4)大型底栖动物的生物量和丰度随着春夏颗粒有机碳脉冲的变化而快速增加。为了验证这些假设，我们将评估海底沉积和颗粒有机碳的不稳定性、颗粒有机碳混合到沉积物中的模式、大型动物和巨型动物丰度的季节变化、生物量和繁殖条件，以及海底颗粒有机碳和二氧化硅矿化和积累的速率。生物源物质和放射性核素进入水中粒子捕集器的通量将与海底沉积和掩埋速率进行对比，以确定这些物质的水柱和海底保存效率。该项目将大大提高我们对WAP大陆架春夏生产脉动及其对南极沿海系统海底群落和碳循环的影响的理解。

OPP98-15823 P.I. Craig SmithOPP98-16049 P.I. David DeMasterPrimary production in Antarctic coastal waters is highly seasonal, yielding an intense pulse of biogenic particles to the continental shelf floor. This seasonal pulse may have major ramifications for carbon cycling, benthic ecology and material burial on the west Antarctic Peninsula (WAP) shelf. Thus, we propose a multii-disciplinary program to evaluate the seafloor accumulation, fate and benthic community impacts of bloom material along a transect of three stations crossing the Antarctic shelf in the Palmer LTER study area. Using a seasonal series of five cruises to our transect, we will test the following hypostheses: (1) A substantial proportion of spring/summer export production is deposited ont eh WAP shelf as phytodetritus or fecal pellets. (2) The deposited bloom production is a source of labile particulate organic carbon for benthos for an extended period of time (months). (3) Large amounts of labile bloom POC are rapidly subducted into the sediment column by the deposit-feeding and caching activities of benthos. (4) Macrobenthic detritivores sustain a rapid increase in biomass and abundance following the spring/summer particulate organic carbon pulse. To test these hypotheses, we will evaluate seabed deposition and lability of particulate organic carbon, patterns of particulate organic carbon mixing into sediments, seasonal variations in macrofaunal and megafaunal abundance, biomass and reproductive condition, and rates of particulate organic carbon and silica mineralization and accumulation in the seabed. Fluxes of biogenic materials and radionuclides into midwater particle traps will be contrasted with seabed deposition and burial rates to establish water-column and seabed preservation efficiencies for these materials. The project will substantially improve our understanding of the spring/summer production pulse on the WAP shelf and its impacts on seafloor communities and carbon cycling in Antarctic coastal systems.