The blueprint for marine biomineralization in a changing climate

This project brings together multidisciplinary researchers to further understanding of biomineralization in a biogeochemically critical group of marine organisms, the foraminifera. Foraminifera are widely distributed in marine systems and are a major sink for atmospheric CO2 through the long-term, deep-sea burial of their calcite shells. Calcification is the principal means by which inorganic carbon is introduced into the deep ocean, exceeding the organic flux of fixed C by about six-fold. How ongoing ocean acidification and warming will affect the size of the foraminifera carbon sink in coming decades is presently poorly understood. This is largely because mechanistic understanding of the biomineralization process in these organisms is very rudimentary when compared to other marine calcifiers. As a result, it is not possible to confidently predict how climate change will impact future carbon inventories and atmospheric CO2 concentrations.

We will target the single-celled foraminifera as a simple model system for marine calcification to provide a blueprint of critical genes and proteins that drive biomineralization, and their response to higher pCO2 and lower pH conditions. Our specific objectives are: 1. Generate the first annotated genomes in both the benthic and planktonic foraminifera. 2. Identify key organic matrix proteins in the calcification process and realize their individual roles in the nucleation, crystallisation and building of the calcite shell. 3. Provide the first mechanistic understanding of gene expression and calcification response under IPCC climate scenarios.