Temperature and Carbonate System Influences on the Test Chemistry of Deep-Sea Benthic Foraminifera: Laboratory Culture Studies

Woods Hole Oceanographic Institution, Woods Hole MA

Investigators

Abstract

Downcore records of benthic foraminiferal shell composition can provide valuable records of deep water temperature and chemistry in the past. While field based calibration studies have defined the relationships between shell chemistry and bottom water conditions, our ability to interpret benthic foraminiferal proxy records continues to be challenged by the fact that multiple factors-- environmental and biological-- can influence most aspects of shell chemistry. Culture-based studies offer a promising complement to core-top calibrations, because in the laboratory it is possible to vary a single environmental variable while holding others constant. This research builds on previously funded culture work, here focusing on demonstrating calcification in culture, and reproduction and subsequent growth in culture, by Uvigerina and Cibicidoides species, two benthic foraminifera widely used in paleoceanography. Samples collected from the mid-Atlantic margin will be cultured under controlled and monitored physical and chemical conditions in order to assess the consistency of foraminiferal oxygen isotope values from the newly-formed shell material. The main focus is on foraminiferal growth and reproduction, which will lay important groundwork for future efforts toward proxy calibrations under variable environmental conditions. A female postdoctoral researcher will have a central role in the project. Other broader impacts include providing sea-going experience for undergraduate volunteers from non-oceanographic institutions.