Marine debris kills wildlife, such as turtles, fish, and birds, and it also exacts costs on coastal communities that must pay for debris removal, lose tourism revenue, and face reduced property values.
In 2007, the Ocean Conservancy released a comprehensive report from the National Marine Debris Monitoring Program, which studied marine debris in 180 coastal states, islands, and territories of the United States from 2001 to 2006. They found that marine debris from the land and the ocean increased by 5% each year of the five-year study. Hawaii was the only location that showed a significant decrease in debris.
During the five year study 238,103 debris items were collected. The debris was classified into three categories: land-based debris, general source debris, and ocean-based debris. Land-based debris, such as straws, balloons, and cans, accounted for 48.8% of all debris. The next greatest source of debris came from general sources, such as plastic bottles and bags, with 34.4% of total debris. Ocean-based debris, including rope, fishing line, and buoys, was the smallest source at 17.7%.
During the five-year study, a total of 196,387 debris items were collected in the continental United States. Land-based and general-source objects made up the majority of debris collected. Only 14.2% of debris came from ocean-based pollution. The amount of land-based and ocean-based debris did not vary significantly over five years. General-source debris, however, increased by 9.8% every year.
Hawaii was the only region of the study that showed an annual decrease in debris, with an average decline of 18.4% per year. In total 30, 171 items were collected, most of which were ocean-based debris. Although ocean-based debris contributed the most pollution, its numbers decreased annually by 23.8% during the study. In addition, land-based debris decreased annually by an average of 11.1% per year. Only 16.5 land-based debris items were collected in the fifth year of the study.