Collaborative Research: Foraminiferal Ecological Response to Ocean Conditions in the Northwest Pacific Ocean

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Foraminifera are tiny, shelled protists that live throughout the ocean. The chemical composition of their shells varies as a function of the ocean conditions during growth. Fossil foraminifera, which are common on the seafloor, are used to reconstruct past ocean conditions and Earth’s climate history. New data show that the mix of foraminifera species present in the Northeast Pacific Ocean is changing rapidly in response to ocean warming events, commonly referred to as marine heat waves. This study will improve our ability to use temperate and high-latitude species in paleoclimate research. It will also help quantify how modern climate change is modifying the species present in this region. The study will include collecting specimens in plankton nets and sediment traps. It will quantify the species present during the sediment trap deployment and will compare the composition of their shells to ocean conditions when they grew. A small number of specimens will be grown in the laboratory and additional specimens will be used for genetic analyses. This project will help show how modern ocean conditions impact the mix of species present in this region and how growth conditions influence the composition of their shells. This project will support two graduate students at Oregon State University (OSU) and multiple undergraduate students at OSU and at the University of South Carolina. Foraminifera shells from this research project will be imaged on a MicroCT scanner to generate 3D images. Those images will then be made available to the broader community for research and teaching purposes. The project will improve the utility of temperate and high-latitude planktic foraminifera in paleoclimate research and quantify the effects of modern climate change on foraminifera assemblages in the Northeast Pacific Ocean. The main objectives are to expand our knowledge of the ecology and environmental controls on the geochemistry of temperate and higher-latitude foraminifera species, quantify their response to modern changes in oceanographic conditions (specifically marine heat waves), and constrain foraminiferal geochemical signatures as they sink to the seafloor. This will be achieved through a significant field-based and laboratory effort that includes newly collected plankton tows, short-duration ship-based culture experiments, assemblage data from archived plankton tow samples, and the deployment of two moored sediment traps. The proposed multi-pronged sampling strategy will provide critical samples needed to understand the biogeochemistry and ecology of foraminifera in this important ocean margin region, increase their utility in understanding past oceanographic conditions, and lay the groundwork for understanding how high-latitude species will respond to future climate change. Highly controlled culture experiments will quantify trace element incorporation dynamics and mechanisms responsible for intrashell trace element variability in temperate to polar species. The results of these experiments will offer important information that can be used to interpret the geochemistry of fossil foraminifera in temperate to high-latitude regions, broaden our understanding of the controls on trace element incorporation in high-latitude and temperate foraminifera species, and improve their utility in paleoceanographic reconstructions. Sediment trap, plankton tow, and cultured specimens will be analyzed for their trace element and isotopic composition. Live captured specimens will be analyzed to determine their genotype and microbiome. Foraminifera and sediment trap samples not used by the PIs in this project will be archived at the OSU Marine Geological Repository for future studies by the scientific community.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.