In any study of organisms in tidal estuarine areas, such as the oyster and its associates, the salinity of the water is of recognized importance as a factor limiting the distribution and controlling the activity (movement, feeding, spawning) of the various species.
Stauber, Leslie A.. 1943. "Graphic representation of salinity in a tidal estuary." Journal of Marine Research 5, (2). https://elischolar.library.yale.edu/journal_of_marine_research/613