The Behavior of 14C and 13C in Estuarine Water: Effects of In Situ CO2 Production and Atmospheric Change

Abstract

The effects of nonconservative sources (inputs) and sinks (outputs) of carbon are indicated by the behavior of Delta-14C and delta-13C of the total dissolved inorganic carbon (Sigma-CO2) in San Francisco Bay and Chesapeake Bay. Isotopic distributions and model calculations indicate that in North San Francisco Bay the net CO2 flux to the atmosphere and carbon utilization in the water column are balanced by benthic production. Municipal waste appears to be a dominant source in South San Francisco Bay. In Chesapeake Bay, atmospheric exchange has increased the Delta-14C and delta-13C in the surface water. Decomposition of organic matter in the water column is indicated to be the dominant source of excess Sigma-CO2 in the deep water.