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.