The vertical structure of total carbon, alkalinity, nutrients, and dissolved oxygen in the world oceans is examined with a one-dimensional equatorial ocean/polar ocean box model. Photosynthesis/respiration cycles affect and are affected by fluxes in the ocean and the structure of the profiles. Marine biota produce by-products that lead to organic and inorganic (calcareous) sediments. In steady state, rates of phosphorous and alkalinity runoff from land are linked to surface nutrient supply, the rates of particulate rain, the degree of anoxia near sediments, the lysocline depth, and thereby control rates of sedimentation. These, in turn, are influnced by internal mixing dynamics and the action of the marine biota. The interdependence of ocean composition and rates of organic and in orgain carbon burial is found to be sensitive to the traits of the marine biosphere. ¿American Geophysical Union 1991