research highlight: removing non-crop habitat does not increase food safety

posted August 19, 2015


Schematic of farm environment using co-management approach for food safety and environment.

In 2006, a deadly Escherichia coli O157:H7 outbreak in bagged spinach was traced to California’s Central Coast region, where >70% of the salad vegetables sold in the United States are produced. Although no definitive cause for the outbreak could be determined, wildlife was implicated as a disease vector. Growers were subsequently pressured to minimize the intrusion of wildlife onto their farm fields by removing surrounding non-crop vegetation. How vegetation removal actually affects foodborne pathogens was unknown. Researchers at UC Berkeley (including Daniel Karp and Claire Kremen of BFI‘s Center for Diversified Farming Systems), UC Davis, the Nature Conservancy, and the Natural Capital Project found that removal of non-crop vegetation did not in fact reduce incidences of enterohemorrhagic E. coli(EHEC). The study actually found a slight but significant increase in pathogen prevalence where non-crop vegetation had been removed, calling into question reforms that promote vegetation removal to improve food safety.