Marine microbes are the engines that drive global biogeochemical cycling in the oceans. They produce and cycle a dissolved organic matter (DOM) reservoir that is roughly as big as the atmospheric carbon dioxide pool (1). Interactions between DOM and marine microbes may also play a key role in the evolving climate through changes in remineralization rates (2). Historically, DOM has been thought of mainly in terms of its carbon, nitrogen, and phosphorus content. On page 456 of this issue, Ksionzek et al. (3) investigate the large pool of dissolved organic sulfur (DOS) compounds in the ocean and show that these compounds also play a key role in ocean biogeochemistry.
Author: Naomi M. Levine