Compositions and transport of lipid biomarkers through the water column and surficial sediments of the equatorial Pacific Ocean

摘要: Abstract A systematic investigation of fluxes and compositions lipids through the water column into sediments was conducted along U.S. JGOFS EgPac transect from l2°N to l5°S at 140°W. Fluxes out euphotic zone varied spatially temporally, ranging ≈0.20 – 0.6 mmol lipid-C m−2 day−1. Lipid were greatly attenuated with increasing depth, dropping 0.002-0.06 day−1 in deep-water sediment traps. Sediment accumulation rates for ≈ 0.0002 0.00003 Lipids comprised 11–23% Corg net-plankton, 10–30% particles exiting zone, 2–4% deep EgPac, 0.1-1 % sediments. were, general, selectively lost due their greater reactivity relative bulk organic matter toward biogeochemical degradation sediment. Qualitative changes lipid are consistent reactive nature lipids. Fatty acids most labile compounds, polyunsaturated fatty (PUFAs) being quickly particles. Branchedchain C15 C17 increased abundance as particulate sank incorporated sediment, indicating inputs bacteria. Long-chain C39 alkenones marine origin long-chain C20-C30 acids, alcohols hydrocarbons derived land plants preserved Compositional over time space demonstrate dynamic range reactivities among individual biomarker hence a whole. thorough understanding reprocessing oceanic is, thus, essential using record reconstructing past environments.