Global Assessment of Micro-plastics in Marine Environment
International experts met in London, UK, from 23 to 25 July 2013 to review the growing problems in the marine environment caused by micro-plastics – tiny pieces of plastic or fibres which may act as a pathway for persistent, bio-accumulating and toxic substances entering the food chain. The experts form a key International Maritime Organization (IMO) working group (WG-40) under the Joint Group of Experts on the Scientific Aspects of Marine Environmental Protection (GESAMP), an advisory body that advises the United Nations (UN) system on the scientific aspects of marine environmental protection.
The IMO is the Administrative Secretariat of GESAMP, which has, to date, produced more than 85 reports, including numerous in-depth technical studies contributing to the assessment on the state of the global marine environment.
The working group, which was meeting for its second session, completed a draft assessment report, covering the inputs of plastics and micro-plastics into the ocean, from land- and sea-based human activities; the mechanisms and rates of particle degradation and fragmentation; the processes controlling particle transport and accumulation; the interaction of micro-plastics with organisms, and potential physical and chemical impacts; and public perceptions about marine litter in general and micro-plastics in particular.
Further meetings will be held later this year and in 2014, with a view to presenting the final global assessment report on micro plastics in the ocean at the 2nd International Ocean Research Conference in Barcelona, Spain, in November 2014.
The principal audience for the assessment consists of the five UN Agencies supporting the work (IMO, United Nations Industrial Development Organization (UNIDO) and the United Nations Environment Programme (UNEP), the International Atomic Energy Agency (IAEA) and Intergovernmental Oceanographic Commission of UNESCO (UNESCO-IOC), as the lead Agency). The group recognised that the results will also be of interest to many other stakeholders, including intergovernmental bodies, regional seas organisations, maritime and relevant land-based sectors, industry, conservation bodies, scientists and the general public.
The workshop brought together experts in chemistry, ecology, eco-toxicology, human toxicology, materials science, physical oceanography, psychology, science-policy interface, social media and waste management, from nine countries on five continents, and observers from PlasticsEurope and the American Chemistry Council.
Plastic debris comes in a wide variety of sizes and compositions and has been found throughout the world’s oceans, carried by ocean currents and biological vectors, such as in the 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. The dumping of plastics into the sea from ships is prohibited under international treaties.
While micro-plastics may not pose an obvious risk to marine life – such as entanglement – due to the small size, nonetheless they may pose chemical or physical risks, especially on micro-fauna. Micro-plastics may also contribute to the transfer of pollutants from seawater to marine life.
