DAILY VARIABILITY IN ABUNDANCE AND POPULATION CHARACTERISTICS OF TIDAL SALT-MARSH FAUNA

Nekton and macrocrustacean population levels and characteristics were studied in two similar tidal marsh creeks. Absolute and area-adjusted data were analyzed to determine variability resulting from daily popul ation fluctuations. Two sampling schemes-intensive 3-d seasonal and pe riodic 1-d-were examined by constructing probability matrices to compa re the accuracy of data comparisons resulting from each scheme. The pr obability of inaccuracies in comparisons of abundance using nonreplica ted sampling schemes ranged from 0% to 100%. Significant differences b etween consecutive day data were observed for population characteristi cs such as blue crab (Callinectes sapidus) sex ratios, spot (Leiostomu s xanthurus) length-weights, killifish: sciaenid ratios, and killifish :blue crab ratios. These data support the need to account for short-te rm variability when assessing mobile aquatic fauna abundance in estuar ine wetlands.