Possible changes in the dynamics of particulate carbon sequestration in the open ocean associated to anthropogenic perturbations of the environment

Abstract

The complex marine carbon cycle as known at present may suffer alterations from the pressure of changing environmental conditions resulting from anthropogenic activities. The biological pump and the resulting sequestration of CO2, that is, the production in the surface ocean of biological particles that ultimately sink and carry to depth a significant quantity of carbon, may be altered by a number of factors: increase of the amount of CO2 entering the surface ocean from the atmosphere, decrease of CO2 dissolution associated to increasing seawater temperature, increase of acidity of the seawater (decreasing pH) associated to increasing CO2 concentration and its implication in several biological compartments and marine aggregate dynamics. Considering these factors, a review of a two decade time-series of downward flux of particles and carbon export is done and the major factors governing particulate carbon sink are reconsidered in the prospect of future predictable changes in the environment. Special attention will be given to the possible consequence of changing water temperature and acidity on carbon export