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World Oceans Day 2020: New IAEA Research Records Dramatic Increase in Microplastic Pollution in Eastern Tropical Pacific Ocean


A plastic bag under water. The current push plastic and micro-plastic to the coast where a large number of unique marine species come to rest and feed, such as marine turtles, sea birds, sea-lions. Microplastics are known to harm marine life, which mistake them for food, and further being consumed by humans via seafood. (Photo: F. Oberhaensli /IAEA)

We celebrate World Oceans Day at a time when about 8 million tons of plastic waste are ending up in the oceans each year, damaging ecosystems and wildlife, according to the UN Environment Programme. The major challenge scientists and policy makers face today is a lack of knowledge on the biological impacts of microplastics in marine organisms. To help anticipate and hence better address marine pollution scenarios in the eastern tropical Pacific Ocean, scientists from the IAEA and Ecuador have recently completed the first-ever, decade-long study on plastic particle abundance in the coastal waters of Ecuador. The study results form a baseline for future research on pollution of marine ecosystems.

The eastern tropical Pacific Ocean is home to some of the world’s most unique marine reserves, including the Galapagos Islands in Ecuador, the Cocos Island in Costa Rica and the Coiba National Park in Panama – all included in UNESCO’s list of World Heritage Sites. “The research has revealed that the microplastic pollution in the eastern tropical Pacific Ocean is set to continue to increase in the coming decades,” said Peter Swarzenski, Acting Director of the IAEA Environment Laboratories. Plastic particles below 5 mm in length are called microplastics, which can be consumed by marine organisms and thus make their way to the food chain, as a recent IAEA study has revealed.

The amount of microplastics in the region is expected by 2030 to increase some 3.9 times compared to 2008 levels. By 2050, this quantity could almost double again, rising by 6.4 times compared to 2008 levels, and by 2100, the amount of plastics in the ocean is projected to be more than 10 times higher than in 2008 unless action is taken to change this trajectory.

(Graphic: IAEA)

One of the crucial findings of this study is that the change in the microplastic abundance over time increases systematically and identically at all the sampling sites. This implies that the source of microplastics pollution is likely not local, but regional and maybe even global in scale. As many of the world’s mega-cities are located near coastlines, adjacent coastal waters are often elevated in marine plastics abundance, which in turn may impact local fisheries and seafood safety.

“It is sad but not surprising to see such a steep increase of microplastic abundance in the region,” said Rafael Bermudez Monsalve, Investigator Scientist from Ecuador supporting the research at the IAEA Environment Laboratories. “This data is crucial for the understanding of future oceanic scenarios and such studies can help policy makers on the implementation of adequate plastic life-cycle management.”

Monitoring marine plastic pollution

Plastics are by design tough and resistant to degradation and have thus over time been found even in the deepest marine trenches. In our oceans, plastic fragments are broken down continuously by ultra-violet light, by the corrosive nature of seawater and by the constant physical erosion due to waves and shear. This continuous degradation supplies a stream of tiny micro and nano-sized plastic particles that can be consumed by marine organism and thus introduced into the food chain.

Filtration on micro-filter of the digestion residues from Galapagos Island waters. These residues are being analysed at the IAEA Environment Laboratories in Monaco to see the potential micro-plastic ingested by the organisms and further studied to characterize the type of plastic. (Photo: F. Oberhaensli/IAEA)

So far, a limited number of research studies have attempted to assess the historic abundance of plastic pollution. There had not been any comprehensive study to have examined a long-time series of marine plastic waste in the eastern tropical Pacific Ocean region. The IAEA research, supported by the Coastal Polytechnic University (ESPOL) and the National Fishery Institute of Ecuador, was based on measuring data obtained from past expeditions and observations of plastics collected from the four stations along the coast of mainland Ecuador including Esmeraldas, Puerto Lopez, Salinas and Santa Clara.

The microplastics under evaluation were classified into three types: fragments (bottles, cups, food containers), fibers (plastic lines and fishing detritus), and film (plastic bags, zip bags). Fibers were found to be the most common plastic particle in the open water. These tiny particles have been found to travel as far as 10 000 kilometers in the Pacific Ocean and have reached even the most remote areas such as Galapagos Islands, polluting its pristine waters and rich wildlife.

“As we continue to develop our research on marine plastics, nuclear and isotopic techniques are playing a particularly important role in advancing both the science and knowledge on the subtle, sustained impacts of microplastic pollution in the marine realm,” said Swarzenski.

Plastic waste at Galapagos coast. Sunlight, wind, waves break down these large plastic debris into smaller and smaller pieces to become microplastics. In addition, some very tiny pieces used as exfoliants in the health and beauty industry and synthetic fibres from clothes are contributing to the micro-plastic pollution. (Photo: F. Oberhaensli/IAEA)

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