The Behavior of ¹⁴C and ¹³C in Estuarine Water: Effects of <i>In Situ</i> CO₂ Production and Atmospheric Exchange

Abstract

The effects of nonconservative sources (inputs) and sinks (outputs) of carbon are indicated by the behavior of Δ 14 C and δ 13 C of the total dissolved inorganic carbon (ΣCO 2 ) in San Francisco Bay and Chesapeake Bay. Isotopic distributions and model calculations indicate that in North San Francisco Bay the net CO 2 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 Bav. In Chesapeake Bay, atmospheric exchange has increased the Δ 14 C and δ 13 C in the surface water. Decomposition of organic matter in the water column is indicated to be the dominant source of excess ΣCO 2 in the deep water.