POLLUTION & THE OCEAN
The ocean has become a receptacle for the world’s pollution. The Ellen MacArthur Foundation and the World Economic Forum jointly predicted that there will be more plastic than fish (by weight) in the ocean by 2050, and the United Nations Environment Programme has recorded more than 817 species of ocean animal that have encountered plastic pollution.
Plastic pollution has also been detected in seafood sold for human consumption; a 2015 study by a team of University of California, Davis and Hasanuddin University researchers flagged man-made debris in 25% of seafood market fish, and 67% of all species sampled in the US.
Researchers have found that just 10 of the world’s rivers are the source of 90% of the plastic pollution entering the ocean, pointing to a possible focus for efforts to curb plastic pollution as a matter of policy and industrial reform - by stopping pollution at its source. Another major source of ocean pollution is the runoff of fertilizers used in agriculture, which are carried down rivers into the ocean where they create population explosions of algae and bacteria. This in turn depletes oxygen levels, killing fish and creating inhospitable conditions for marine life.
The most harmful ocean pollutant is - far and away - carbon pollution. In the last decade, the ocean has absorbed nearly a third of the carbon dioxide emitted by industrial activity. This has slowed climate change, but at great cost to ocean health. When carbon dioxide is absorbed by seawater it increases acidity levels, and threatens ocean life ranging from the microscopic snails that feed salmon to the coral reefs that support tourism. Plastics are another particularly insidious form of ocean pollution; according to the non-profit Ocean Conservancy, coastal nations generate 275 million metric tons of plastic waste every year (and 8 million metric tons of plastic enters the ocean).
As a result, more than 400 low-oxygen “dead zones” have been documented in the ocean worldwide. The spread of these areas could be limited, in a way that also saves money for the agriculture industry, by deploying a more strategic and responsible application of fertilizers.
According to a report published in the journal Science Advances in 2017, only 9% of plastic waste has been recycled globally - highlighting a need to re-think design and regulation in a way that incentivizes re-use. Potential solutions include policies that curb the use of single-use plastics like bags or straws, or improving the capture of plastics that leak out of waste systems.