Much of what is now Los Angeles, in southern California, was once a teeming wetland. A landmark survey going back 8,000 years has found that human settlement in the region has ebbed and flowed with the levels of the sea and the waters of the Los Angeles River.
     Since 1989, a team of scientists has conducted scores of archaeological surveys, drilled dozens of cores into the coastal soil, and pored over countless microscopic fossils to reconstruct the environmental and human history of Los Angeles. They found that the historical heart of L.A. has been the marshy flats now known as the Ballona wetlands.
     Today, the wetlands are little more than a grassy inlet near the upscale development of Marina del Rey.
     Dr Richard Ciolek-Torello, who helped lead more than 100 archaeologists in the research, says that from a somewhat mysterious thousand-year abandonment of the region around 4000 BCE to an equally sudden population explosion some 2,000 years ago, the history of ancient L.A. seems to have been driven by its coastal marshes.
     "Although other studies have dealt with aspects of aboriginal life or certain time periods, our studies deal with the entire sequence of occupation from the first evidence of human settlement in the Ballona area to the abandonment of the last site."
     Human occupation of the area likely began as long as 11,000 years ago, based on evidence elsewhere in Southern California, but in Los Angeles any sites from that long ago are likely underwater, as sea levels rose by some 20 meters after the last great glacial melt.

Edited from Western Digs (25 February 2014)