Mud's Real Job: Housing Microbes and Keeping Old Climate Records

Mud has a public-relations problem and a serious scientific résumé. In 1970, the same year as the first Earth Day, ecologist Edward Deevey wrote that mud — the essential habitat of certain essential microorganisms — is just as important as water to the economy of this planet. As JSTOR Daily notes, he wasn't being hyperbolic; half a century later the case has only become more apparent to researchers studying muddy sediments in ponds, lakes, swamps, estuaries and oceans, where those microbes live. That alone would be a decent argument for taking mud seriously. The more surprising payoff is archival: because so few larger organisms can live in mud — worms and clams being the exceptions — it makes an excellent medium for studying past climates. The scarcity of residents is the feature, not the bug.