 As waterbirds that feed on fish, pelicans are highly susceptible to oil spills, both directly by being oiled and by the impact on their food resources.A 2007 report to the California Fish and Game Commission estimated that during the previous 20 years, some 500–1000 brown pelicans had been affected by oil spills in California.A 2011 report by the Center for Biological Diversity, a year after the April 2010 Deepwater Horizon oil spill, said that 932 brown pelicans had been collected after being affected by oiling and estimated that 10 times that number had been harmed as a result of the spill.