El Niño-Southern Oscillation is a warming of surface sea temperatures in the eastern Pacific Ocean. Such climatic and oceanographic perturbations have dramatic impacts upon human adaptation and sociocultural development. Evidence multidisciplinary Artificial a mound of dirt in the ceremonial center of Valdivia The Emerancia have documented the abandonment of the site in relation to the El Niño phenomenon. The intial site abandonment was in response to intense or mega event dated to 2150 BC, associated withe the formation of the beach, singing fossil reoccupation C14 and dated ca 2200-1450 BC and final abandonment dated to 1450 B.C. Final abandonment is associated with an earthquake and a short-lived reoccupation. Data from excavation, regional settlement patterns and shellfish frequencies are presented to determine whether repeated and final site abandonment was related to El Niño. Results indicate widespread environmental degradation and geomorphological changes to the surrounding coastline were related to El Niño, and that it was clearly a factor to sociocultural development and adaptive responses. These data explore chronology, assess the intensities, and measure the effects of ancient El Niño events upon pre-Hispanic occupations this ceremonial center and pre-Hispanic occupations along the Arenillas River valley, El Oro Province, Ecuador.