DTDRP reports from 2007 to 2011 were provided by the National Park Service containing spatial debris collection locations, debris type and quantity per search day, and number of days comprising the removal effort (note: spatial debris collection locations were not recorded in 2007). As previously noted, two different independent contractors were used to conduct the debris removal. To preserve contractor anonymity, they will be referred to as Contractor X and Contractor Y. A comprehensive benthic habitat map for BNP (Estep et al., 2012) was used in conjunction with bathymetric data provided by the National Oceanic and Atmospheric Association (NOAA) Office of Coast Survey (http://www.nauticalcharts.noaa.gov/).