FollowScientists from the University of Cadiz, Spain, went on research cruise around the world in an attempt to reassess the level of pollution with plastic of the Earth’s oceans. They were surprised to find out that the estimate of ocean plastic pollution is only around 7000t to 35000t.
Where is the rest of the ocean plastic pollution?
Andres Cozar of University of Cadiz was surprised. Based on data going back as far as the 1970s he initially reached the conclusion that by now 1 million metric tons of plastic debris would lie in the oceans. The National Academy of Sciences estimated in 1970s that about 45,000 tons of plastic spread in the oceans annually. In 1988, the US National Oceanic and Atmospheric Administration already foresaw the pollution patches and the founder of Algalita Marine Research Foundation identified the first one in 1988. So is there more ocean plastic pollution today?
Microplastics were found in 88 percent of the water surfaces sampled in the Malaspinsa expedition, which took place in 2010. The ocean currents, as expected, shape the density of the plastic debris. Five high density areas have been identified so far. One of them is the West of the U.S., another lies between the U.S. and Africa, a third one is in the west of southern South America, with the last two around the southern African tip.
There are a couple of hypotheses on this. One would be that a large part of the plastic disintegrated. Another is that marine animals consumed it. It means that the plastic debris has entered the food chain. If so, it is a matter on which scientists have no idea yet regarding the consequences. A third hypothesis would be that some of the plastic lies more in depth or even at the bottom of the oceans. The samples taken in this research came from the surface water, thus the research data is not able to answer completely the question on what happens to ocean plastic pollution. The problem is that most of the plastic smaller than 0.2 inches (5 mm) were not there. Cozar warns that “most of the impacts taking place due to plastic pollution in the oceans are not yet known”. It is an unsettling perspective. Let’s all refrain from throwing plastic and, as possible, from using plastic in the first place.
The results of the research have been published today in the journal ‘Proceedings of the National Academy of Sciences’.
