Spatial and temporal variations in six Cumberland Basin saltmarsh margin and tidal creek patterns were measured and possible controls on their evolution explored at the decadal scale. Measurements of marsh change were made using aerial photograph sets from the 1940's-1990's. Field measurements and historic weather data were used to explore possible controlling variables. It is clear that the Cumberland Basin saltmarsh system is very dynamic and that episodic changes are normal. Differences in saltmarsh morphology were found to be primarily a function of saltmarsh evolutionary stage and some key, site-specific external variables. A conceptual model was developed to illustrate the evolutionary stage. The most important non-site-specific external variable studied is the relative 'storminess' of a time period. This is apparent from the overall retreat measured during the period 1960-1970. It was also found that the creek networks present in the saltmarsh and mudflat environments are quite stable in terms of location and morphology.