It is widely recognised that marine litter can have significant ecological, social and economic impacts. Plastics form a large proportion of marine litter, and the widespread occurrence of macroscopic plastic debris and the direct impact this can have both on marine fauna and legitimate uses of the environment, sometimes remote from industrial or urban sources, has been well documented. Plastic debris comes in a wide variety of sizes and compositions and has been found throughout the world ocean, carried by ocean currents and biological vectors (e.g. stomach contents of fish, mammals and birds). Plastics degrade extremely slowly in the open ocean, partly due to UV absorption by seawater and relatively low temperatures. In recent years the existence of micro-plastics and their potential impact has received increasing attention. The extent of the impact of plastic litter in the oceans is uncertain, despite the considerable scientific effort that has been expended in recent years.
The IOC is actively engaed in and sponsoring a UN multi agency working group on "Sources, Fate and Effects of plastics and micro-plastics in the marine environment". This is within the Joint Group of Experts on the Scientific Aspects of Marine Environmental Protection (GESAMP) which is an advisory body, established in 1969, that advises the United Nations (UN) system on the scientific aspects of marine environmental protection.
GESAMP WG 40