Benthic Foraminifera that occupy these regions are a highly adaptable species due to it's biology.  Some of these  'paralic species' can inhabit hyposaline and hypersaline environments.  (They are salinity-tolerant)  In estuaries, they can be used as salinity indicators based on the spatial distribution of salinity.

Other Paralic Species:

In choked lagoons, Calcium dominant species are abundant.
(Calcium carbonate indicators)

In Peripheral marshes, agglutinated species of forams are dominant because of the fresh water input, abundance of organic matter and low pH levels.

    Another reason by Benthic Foraminifera are very useful is because they have short life-cycles so they react quickly to subtle variablility in the environment.  Furthermore, they can be used as 'early warning indicators' to major environmetnal changes.

Note:  although they are very useful, more field studies and laboratory experiments are necessary before forams can be used alone to make a reliable distinction between anthropogenic and natural stresses.