First of all, if you are refering to Kelso Bayou, yes, that is a lot of mudflat and open water. Second, I did not mean or say that it would convert to that over time with no influence. What I meant by that was, if you have any disturbance such as a drought or hurricane, there is the potential to lose marsh which turns into mudflats. Mudflats then become deeper if plants do not recolonate the flats. In a salt marsh, when the flats get deeper, species cannot recolonate them because they cannot tolerate deep water as well as brackish or fresh species can. Thus you lose marsh and the only way to regain it is to go in with large scale dredging and filling projects. And FYI, Kelso Bayou is not a natural salt marsh. Salt marshes naturally occur close to the Gulf of Mexico in the majority of this region:
http://www.wlf.louisiana.gov/sites/d...salt_marsh.pdf
Looking at a map, there is one place that salt marsh "naturally" occurs, and I only say that because historically it was not salt marsh either.