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

OPP98-15823 P.I.克雷格·史密斯OPP98-16049 P.I.大卫·德马斯特南极沿海水域的初级生产具有高度季节性，产生强烈的生物来源颗粒脉冲进入大陆架底部。这种季节性脉动可能会对西南极半岛(WAP)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计划，以评估沿Palmer LTER研究区穿越南极陆架的三个站点的横断面上水华物质的海底堆积、命运和底栖群落影响。使用我们横断面的五个航次的季节序列，我们将检验以下假设：(1)相当大比例的春季/夏季出口产品作为植物碎屑或粪便颗粒存放在WAP货架上。(2)沉积的水华产物是较长时期(几个月)底栖动物不稳定颗粒有机碳的来源。(3)大量不稳定的水华POC在底栖生物的捕食和截留作用下迅速潜入沉积物柱中。(4)大型底栖有害动物在春季/夏季颗粒有机碳脉冲后，生物量和丰度保持快速增长。为了验证这些假设，我们将评估海底颗粒有机碳的沉积和稳定性、颗粒有机碳混合到沉积物中的模式、大型动物和大型动物丰度的季节变化、生物量和繁殖条件，以及颗粒有机碳和二氧化硅在海底的矿化和积累速率。生物来源材料和放射性核素进入中水颗粒捕集器的流量将与海底沉积和埋藏率进行对比，以确定这些材料的水柱和海底保护效率。该项目将大大提高我们对WAP大陆架春季/夏季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了解。

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.