New applications in foraminiferal research have focussed on solving environmental issues in humanly altered coastal systems. Such research is also useful for the interpretation of the history and evolution of ancient harbors since it can aid in the identification of past human alterations of coastal environments in marine archaeological sites. Understanding the evolution of harbors is important for archaeological studies since harbors represent the interface between land and marine based trade systems. In order to understand the nature and evolution of this interface, and ultimately to derive a coherent understanding of the evolution of ancient trade routes, a clear understanding of coastal evolution is required.

The distribution of foraminifera in coastal environments can be related in many instances to salinity regimes. This information is important to harbor studies since the salinity regime within the harbor is closely linked to the form and function of the harbor structure. Shifts in salinity within the harbor can be due to anthropogenic alterations of the harbor structure itself or due to natural agencies such as sea level change, seismic activity (subsidence or uplift), climatic change, or changes in sedimentation both inside and outside of the harbor; all of which can cause the demise of the harbor.

The utility of foraminiferal analysis in archaeological studies is highlighted by our recent research on Lechaion, the western harbor of ancient Corinth, Greece. Foraminiferal analysis of cores taken from the inner harbor reveals a sharp transition: from a marine lagoon system representative of the active ancient harbor to a restricted freshwater and then to a slightly brackish environment which indicates the demise of harbor activity in the 5th – 6th c. AD. The demise of the harbor was due to coseismic uplift since the same transition was recorded in all seven cores and wave cut notches on the harbor structures are presently located 1.7m above modern sea level. Consequently, foraminiferal analysis provided baseline information regarding the nature and evolution of Lechaion, including the dates when the harbor was active, and how and when it was destroyed. This information was recovered with less time and effort and with more efficiency than with traditional excavation methods.