Thorough faunal (benthic foraminifera, ostracods, molluscs) and palynomorph analyses as
well as magnetic susceptibility measurements performed on the Piraeus coastal plain sedimentary
sequences have shed light on the paleoenvironmental evolution of the area since ca. 9000 cal BP.
Benthic and palynomorph assemblages along with magnetic susceptibility suggest a typical lagoonal
environment with significant freshwater inputs at the eastern part of the plain after 8700 cal BP.
Between 7500 and 5400 cal BP, microfaunal assemblages, mollusc fauna and magnetic susceptibility
suggest a shallow marine paleoenvironment, with Piraeus forming a tied island in the center of the
bay. Since ca. 4800 cal BP a closed oligohaline lagoon is evidenced in the western part of the Piraeus
plain further developed to a marsh after 2800 cal BP, while a coastal environment associated with the
fluvio-deltaic system of Kifissos and Korydallos Rivers is continually developing to the west. Signs of
cultivation and grazing activities in the area are evidenced since the Early Bronze Age, culminating
during the Classical Period. A comparison with a well-dated marine record, recovered from the
nearby shallow Elefsis Bay, provides a reasonable estimation of ~5 mm/yr for the absolute sea level
rise rate in the inner Saronikos Gulf during the Mid-Holocene.