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OPP 98 -16049 P.I.大卫DeMaster初级生产在南极沿海沃茨是高度季节性的，产生了强烈的脉冲生物颗粒的大陆架地板。 这一季节性变化可能对南极半岛（WAP）大陆架西部的碳循环、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，以评估海底积累，命运和底栖生物群落的影响，水华物质沿着一个横断面的三个站穿越南极大陆架在帕尔默LTER研究区。 使用一个季节性系列的五个巡航到我们的样带，我们将测试以下假设：（1）春季/夏季出口产品的相当大的比例是沉积在WAP架作为植物碎屑或粪便颗粒。 (2)沉积物水华的产生是底栖生物长期（数月）不稳定颗粒有机碳的来源。 (3)大量的不稳定水华POC通过底栖生物的摄食和缓存活动迅速潜到沉积物柱中。 (4)在春季/夏季颗粒有机碳脉冲之后，大型底栖食肉动物的生物量和丰度迅速增加。 为了检验这些假设，我们将评估海底沉积和颗粒有机碳的不稳定性、颗粒有机碳混入沉积物的模式、大型动物和巨型动物丰度的季节性变化、生物量和生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流入中层水粒子收集器的通量将与海底沉积和埋藏速率进行对比，以确定这些物质的水柱和海底保存效率。 该项目将极大地提高我们对WAP大陆架春季/夏季生产脉冲及其对海底群落和南极沿海系统碳循环的影响的认识。

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.