Due to eustatic changes of sea level, tectonic activity, isostatic and
compactional depression, and erosion, a considerable number of archaeological
land sites are now underwater. East of San Juan, Puerto Rico,
underwater archaeological excavation at Isla Verde site revealed a
coastal settlement inhabited circa A.D. 800 by Arawak Neo-Indians.
Classified in the Ostiones phase by its ceramic ware, the site preceded
the Talno chiefdoms encountered by European explorers at the close of
the fifteenth century. Built near the ocean, in a once secluded area
surrounded by two lagoons and a mangrove belt, Isla Verde site was
characterized by coastal and maritime adaptations such as shellfish
collecting and the hunting of manatees and turtles. Cultivation of
root crops was also part of the subsistence pattern. The site was
submerged as a result of erosion produced by wave patterns diffracted
by offshore reef patches. The archaeological potential and limitations
of the site were evaluated, in conjunction with the recent geologic
history of the area.