Cifuentes, L. A.. Texas A&M University, cifuentes@ocean.tamu.edu
Kaldy, J. A.. Texas A&M University, kaldy@nitro.tamu.edu
Eldridge, P. E.. US EPA,

 
AN INVERSE MODEL OF CARBON CYCLING IN THE NUECES ESTUARY, TEXAS: IMPORTANCE OF ISOTOPIC CONSTRAINTS
 
An advantage to applying inverse techniques in foodweb models is that ranges of field and laboratory measurements and historical information are utilized by this method. Stable carbon isotope measurements constitute a significant fraction of the data base for near-shore and coastal foodwebs. However, few publications have discussed their value to inverse models. We used the inverse approach to describe carbon flows in the Nueces Estuary, a shallow system on the Texas coast, which receives minimal freshwater inflow from the Nueces River and exchanges saline water with Corpus Christi Bay. Isotopic data (dissolved inorganic and organic carbon, benthic macroalgae) obtained in May and August 1998 and literature values (e.g., detritus, zooplankton, infauna, fish, etc.) were included in a series of linear equations and inequality constraints. The model was run with and without isotopic equations and constraints. In both cases, results indicated that in situ production, which cycled through detritus as opposed to the traditional plankton food chain, was the major carbon input. However, the predicted magnitude of allochthonous inputs (river/marshes) was markedly different when isotopes were included in the model.
 
Day: Wednesday, Feb. 3
Time: 09:30 - 09:45am
Location: Eldorado Hotel
 
Code: SS32WE0930E