REU: Phytoplankton Flux in the Gulf of California: Seasonal Variations, Sediment Preservation, and the Last Glacial-Interglacial Transition

这是对最近资助的一个项目的补充，该项目每两周在加利福尼亚湾的东西两侧深入沉积物陷阱，为期两年，将涵盖大量通量，浮游有孔虫，放射虫和稳定同位素的工作。本研究将集中于四组可保存的浮游植物微化石——硅藻、硅鞭毛虫、恐龙鞭毛虫和钙质纳米化石。将确定每个分类群的通量，并将捕集器基物质的组成与箱芯回收的下垫表层沉积物的组成进行比较。该研究将考察浮游植物的季节演替及其年际和空间变化，以确定原始季节信号在沉积物中保存的程度。浮游植物的变化将以1000年为间隔在整个核心部分进行检查，在东部和西部，以解决有关季节性上升流变化的问题以及降水和河流径流变化的证据。该研究将扩展一个正在开发的模型，以描述硅藻从生物群落到生物群落的转变，并为钙质纳米化石和硅鞭毛虫建立一个一级范围模型。

This complements a recently-funded project to deply biweekly sediment traps for two years on the eastern and western sides of the Gulf of California which will cover work on bulk fluxes, planktonic foraminifera, radiolaria and stable isotopes. This study will concentrate on four preservable groups of phytoplankton microfossils--diatoms, silicoflagellates, dino- flagellates and calcareous nannofossils. Fluxes of each taxon will be determined, and the composition of the trap-based material compared with that of underlying surface sediments recovered by box cores. The study will examine the seasonal succession of phytoplankton, and the internannual and spatial variation thereof, in order to determine the degree to which the original seasonal signal is preserved in the sediments. Changes in phytoplankton will be examined at 1000 year intervals throughout the cored section, on eastern and western sides, to address questions concerning changes in seasonal upwelling and evidence for changed precipitation and river runoff. The study will expand upon a model being developed to describe the transformation of biocoenosis to taphocoenosis for diatoms, and produce a first-range model for calcareous nannofossils and silicoflagellates.