The transition from the Middle Preceramic (8000-4500 cal BP) to the Late Preceramic Period (4450-3800 cal BP) in coastal Peru witnessed a dramatic change in both resource management and subsistence practices: lomas environments were abandoned in favor of riparian and littoral ecozones, while hunting and gathering was increasingly replaced by agriculture. The reason behind this transition remains a subject of debate; it has been attributed to population pressure, the development of domesticates, especially maize, environmental degradation or climate change. A recent regional study (Beresford-Jones et al., 2015) supports the 1960s Edward Lanning hypothesis that a combination of environmental and climate change forced Middle Preceramic occupants to move toward the river estuaries on the South Coast. Here, microbotanical data from the Late Preceramic site of El Paraiso on the Central Coast of Peru tests the Lanning hypothesis at the site-scale. The data demonstrate that inhabitants practiced a seasonal, Broad-Spectrum strategy by taking advantage of an ENSO-related florescence. Meanwhile, a trend toward increased salinity of nearby marshlands impacted the continued occupation of the site.