The Migration of the Marine Tumbleweed BY Greenmeme (Freya Bardell & Brian Howe) floats north of the Santa Monica Pier as part of the GLOW art festival on Saturday, July 19, 2008. Marine tumbleweed refers to the “trash vortex”, an area located in the Pacific Ocean and larger than Texas, composed of plastic bottles and other detritus from civilization.Tumbleweed will use recycled plastic bottles, aggregated and composed into large floating tumbleweeds, illuminated from within by LEDs and floated at varying distances from the Pier.