Researchers from the Sea Education Foundation have mapped concentrations of plastic in the Northern Atlantic Ocean and identified a ‘garbage patch’ similar in size to the one in the Pacific.
Over 22 years, plastics were skimmed from the the ocean using surface plankton nets in more than 6000 locations. The concentration of plastic debris is measured for each square kilometer and recorded. They were able to identify gyres, like those in the Pacific, which are effectively circular currents which pull in the plastics and keep them in a single location. In some areas researchers found up to 250,000 pieces per square kilometer.
Using satellite monitoring of more than 100 buoys, they also established that the path of the plastic typically begins at the eastern seaboard of the US and takes around 60 days to reach the gyres. It is believed that most of the material travels from shore, although shipping can also make a significant contribution to the pollution.
Much of the waste is made up of bottles and other packaging, but significant danger is also presented by partially decomposed materials and small particles . Once in the food chain, these can be highly toxic to birds and marine life. Plants and animals can also attach themselves to the items which freely drift in the ocean currents, disrupting the distribution of these creatures.
Another interesting result of the survey was that the concentration of plastic has not increased over the 22 year duration of the study, despite a huge increase in the use of these materials in the same period. It is unknown where the missing waste has gone.
For more information on this study and the most recent voyage visit the Sea Education Association website.