Foraminifera Flux and species composition in Guaymas Basin, Gulf of California (1991-1997)

Paleoclimate records based on planktic foraminifera shells are reliant upon an understanding of how populations respond to annual and interannual changes in surface hydrography. In particular, annual and interannual flux variability would be expected to impact the interpretation of geochemical proxies from foraminifera shells. A seven-year time series from Guaymas Basin, Gulf of California reveals a seasonal progression of foraminiferal species flux, with faunal assemblages characteristic of winter, summer, and fall conditions. We find that both species abundances and phenology are altered during negative El Niño Southern Oscillation (ENSO) phases, as occurred over the course of the study period.

基于浮游有孔虫（planktic foraminifera）壳体的古气候记录，依赖于对种群响应表层水文年度及年际变化规律的理解。尤其值得注意的是，通量的年度及年际变异性预计会影响对有孔虫壳体地球化学代用指标（geochemical proxies）的解读。来自加利福尼亚湾瓜伊马斯盆地（Guaymas Basin, Gulf of California）的七年时间序列数据显示，有孔虫物种通量呈现季节性演替特征，其动物群组合分别对应冬季、夏季及秋季的典型环境条件。研究发现，在观测期间出现的厄尔尼诺-南方涛动（El Niño Southern Oscillation, ENSO）负相位阶段，物种丰度与物候均发生显著改变。