In Franchthi Cave, a thick Upper Palaeolithic through Neolithic sequence (ca. 23,000-5000 BP) of occupational deposits has been excavated. As might be expected at a site now only a few meters from the sea, this sequence has yielded ample evidence for the use of marine resources, though only from ca. 11, 000 BP onward. Moreover, the marine molluscan record exhibits drastic changes in composition over time, implying either major variation in availability or selective collecting. A marine geophysical study supplemented by an examination of present shore environments in the area has permitted the reconstruction of the changing coastal environments since ca. 20, 000 BP, thus providing an estimate of the probably available shellfish resources. Comparison with the molluscan assemblages found in the cave demonstrates that only during the latest Palaeolithic and most of the Neolithic were the collected shellfish reasonably representative of what should have been available in the area. At other times the inhabitants made highly specialized, seemingly idiosyncratic choices from the spectrum of available species. See also abstract of article by Thomas, K.D. in this AATA issue.