The behavior of ¹⁴C and ¹³C in estuarine water: Effects of In situ CO₂ production and atmospheric exchange

The effects of nonconservative sources (inputs) and sinks (outputs) of carbon are indicated by the behavior of Δ¹⁴C and δ¹³C of the total dissolved inorganic carbon (ΣCO₂) 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 Bav. In Chesapeake Bay, atmospheric exchange has increased the Δ¹⁴C and δ¹³C in the surface water. Decomposition of organic matter in the water column is indicated to be the dominant source of excess ΣCO₂ in the deep water.