Production and decomposition rates were calculated for Spartina patens in a mesohaline coastal marsh in Louisiana. Production was estimated to be 800 g m2 yr-1 during 1991 and 1,696 g m-1 yr-1 during 1992. The relative decomposition rate of S. patens stems was -0.001152 g g-1 d-1 which may be restated as a half life of 395 days. Both production and decomposition rates for this area are
low relative to most other studies in coastal areas. These data contribute to our understanding of the dynamics of organic matter in degrading coastal wetlands.