UNEP Year Book 2011/Plastic Debris in the Ocean Every year large amounts of plastic debris enter the ocean, where it slowly fragments and accumulates in oceanic gyres. Scientists are concerned about the possible impacts of small plastic fragments—microplastics—in the environment.
The role of plastics as a vector for transporting chemicals in the ocean is as yet poorly understood, but it is a potential threat to ecosystems and human health.
Of special concern are the accumulation of Persistent, Bio-accumulating and Toxic substances (PBTs) in small plastic particles. All kinds of plastic debris, from nets and other fishing gear to the thousands of different consumer items that find their way to the ocean, break down into fragments that can absorb PBTs that are already present in seawater and sediments. PBTs include polychlorinated biphenols (PCBs), polyaromatic hydrocarbons (PAHs), hexachlorocyclohexane (HCH) and the insecticide DDT, together with other Persistent Organic Pollutants (POPs) that are covered under the Stockholm Convention. Many of these pollutants, including PCBs, cause chronic effects such as endocrine disruption affecting reproduction, increases in the frequency of genetic mutations (mutagenicity) and a tendency to cause cancer (carcinogenicity).
Some scientists are concerned that these persistent contaminants could eventually end up in the food chain. The concentration of contaminants by microplastic particles presents the possibility of increasing exposure to organisms through ingestion and entrance into the food chain—with the prospect of biomagnification in top-end predators in the food chain such as swordfish and seals. There is currently great uncertainty about the degree to which this poses a threat to human and ecosystem health.
Improved waste management is the key to preventing plastic and other types of litter from entering the ocean.
Safe Planet is working with UNEP´s Division on Early Warning and Assessment and other partners to raise public and political awareness of the global scale of the plastic debris problem, together with the larger issue of marine litter, and the emerging issue of microplastic particles and toxic chemicals.
UNEP Year Book 2011/Plastic Debris in the Ocean
(SANTA MONICA, CA) APRIL 25, 2011—Capping the most extensive study of marine plastic pollution ever undertaken, pioneering researchers with the 5 Gyres Institute have completed their fifth expedition through all five subtropical gyres, the massive oceanic current systems where plastic pollution accumulates.
On Friday, 10 December 2010, the Two Oceans Aquarium, in conjunction with the 5 Gyres Institute, the United Nations Safe Planet Campaign and Simon MAX Bannister, hosted a media conference on the crisis of plastic pollution in the oceans at the Aquarium.