SALINITY CONTROL ON THE DISTRIBUTION OF SALT-MARSH FORAMINIFERA (GREAT-MARSHES, MASSACHUSETTS)

Foraminiferal faunas along 12 transects through high and upper marsh v ary with salinity and show no relationship with elevation above mean s ea level. Salinity is diluted by precipitation and seepage of ground w ater and is therefore independent of elevation. Based on salinity valu es and hydrological situation, the marsh habitat is divided into three salinity-based units, each characterized by a different foraminiferal assemblage. An important low salinity indicator is Haplophragmoides m anilaensis. In the Great Marshes, foraminifera can be used in paleoeco logical studies but not as indicators of minor sea level changes.