Microorganisms participate in the construction of manganese nodules

Abstract

THE geographical distribution and formation of manganese nodules have inspired investigation and speculation for more than a 100 years (for example, refs 1 and 2). Although photographs have revealed that some organisms attach themselves to Mn nodules on the deep seafloor (for example, ref. 3), these were apparently epiphytes, not contributing to the formation of the nodules. I now wish to suggest, on the basis of an ultrastructural examination of Mn nodules, that several groups of organisms are active in their construction.