Delineation of modern foraminiferal populations of two SPARTINA ALTERNIFLORA marshes on St. Catherines Island will aid in future interpretation of relict marsh muds. Foraminifera and meiofauna in Engineer Point Marsh (EP) and Hoke's Landing Marsh (HL), two SPARTINA marshes with distinct hydraulic and sedimentologic characteristics, were investigated (1) to determine whether foraminifera comprise a notable proportion of the meiofaunal size fraction, and (2) to characterize foraminiferal populations in the low marshes. Surface cores of 20 cubic centimeter volume were stained and preserved; all representatives of the stained meiofaunal fraction and both the stained and unstained foraminiferal fraction were identified and tallied. Foraminiferal populations form a substantial fraction of the meiofaunal size fraction. Ecological studies of meiofauna should therefore include foraminifera.

AMMONIA BECCARII and AMMOTIUM SALSUM dominate the foraminifera assemblages in both marshes, but populations of the two marshes are best distinguished using the rarer species. Samples contain far more species (145 and 107 in EP and HL, respectively) than have been enumerated in previous marsh studies; the majority of species in each marsh represent less than 2% of the sample assemblage. The standard counts of 300 specimens utilized in most foraminiferal studies may result in notable underestimation of species diversity. Live to total ratios indicate different taphonomic processes dominating in each marsh, with enrichment of agglutinated taxa in the total assemblage. The higher energy hydraulic regime of EP marsh favors postmortem transport of empty calcareous tests and retention of the coarsely agglutinated AMMOTIUM/AMMOBACULITES group. Lower hydraulic regime of HL marsh results in dissolution of calcareous tests and accumulation of the finer agglutinated taxa. Comparison of the modern to a relict marsh mud fauna described by Goldstein (1988) indicates additional taphonomic processes may be occurring.

Foraminiferal assemblages are similar to those found on Sapelo Island, Georgia, and are closer to Gulf of Mexico faunas than to faunas of New England and Nova Scotia marshes. It is important to recognise these differences in initial species composition if we wish to interpret the paleoenvironment of relict assemblages.