Diatoms Like It Light! How Diatom Eating Habits Help Us Understand the Past Ocean

Abstract

Have you ever wondered if today’s oceans were different millions of years ago? Well, a group of small algae called diatoms can help us to find this out. Diatoms build a strong glass skeleton, like a shell, which can last for thousands and even millions of years after their deaths. To build their glass skeletons, diatoms take up silicon from the seawater, similar to us eating food to build our bodies. Diatoms preferentially use one type of silicon in their menu, leaving behind the type they do not like. Researchers can track this eating habit by measuring the proportion of the two types of silicon stored within diatoms. Using this silica-print like a fingerprint, scientists can investigate what the surface ocean was like, how much diatoms were eating silicon, and how these organisms have affected Earth’s past climate.