Journal of California and Great Basin Anthropology

For some time, an interpretation of coastal occupation in the San Diego area of southern California, herein termed the Coastal Decline Model, has held center stage despite limited and patchy empirical data. This reconstruction, based largely on the Batiquitos Lagoon fieldwork of the 1960s to 1980s, posits a major depopulation of the coast during the Late Holocene as estuarine subsistence productivity declined under the impact of rapid siltation. Recent investigations at nine shell midden sites along the coast of Camp Pendleton Marine Corps Base in the northern portion of this region challenge prior inferences. In this area, emerging trends in settlement and subsistence strategies suggest critical shifts took place during the Middle to Late Holocene. Specifically, three new results contradict key test implications of the Coastal Decline Model: (1) numerous coastal sites are now dated to the Late Holocene when marine transgression is thought to have "shut down" extensive coastal occupation; (2) Late Holocene sites are not typically smaller and/or more reflective of short-term or single season occupation than earlier sites; and (3) shellfish remain important to the coastal economy throughout the Holocene. It is argued that resource intensification played a major role in the continued occupation of this portion of coastal southern California.