In the ancient oceans, green rust's ability to pull nickel out of the water would have been critical for some life forms, since nickel is an important nutrient for microbes that produce methane.
By looking at which creatures flourish in their mesocosms, Ulf Riebesell of the Leibniz Institute for Marine Studies in Kiel and his colleagues hope to see changes as they take place by keeping an eye on the water chemistry and nutrient levels.