Seawater Transport During Coral Biomineralization
Coral build their skeletons from calcium and other ions in seawater. What pathways control the transport of these ions? Furthermore, do these same pathways act as links between ocean chemistry and skeletal growth? The answers to these questions can explain the response of coral to ocean acidification and help paleoceanographers improve records of past climate.
Previous research with bulky fluorescent dyes suggested that there was a pathway involving direct seawater transport to the calcifying fluid in coral. Such a pathway linking the site of calcificatin to the surrounding ocean could help explain why coral respond to changes in seawater chemistry. Using a combination of NanoSIMS analysis, stable isotope probes, and coral culture, we developed a new technique to test for this seawater pathway and to measure the rate of this transport process. We then developed an analytical geochemical model to explore the implications of direct seawater transport on skeletal composition. Finally, we tested these predictions against measurements from deep-sea coral.