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，有赖于对其种群如何响应表层水文状况的年内与年际变化的认知。尤为关键的是，年内及年际的通量变异性，势必会影响对有孔虫壳体地球化学代用指标的解译。取自加利福尼亚湾瓜伊马斯盆地的7年时间序列数据，揭示了有孔虫物种通量的季节演替规律，其对应的动物群组合分别具有冬季、夏季与秋季的环境特征。本研究期间观测到，在厄尔尼诺南方涛动（El Niño Southern Oscillation，ENSO）负相位时，有孔虫的物种丰度与物候特征均发生改变。