This week, Greenland launched two “Plastic in a Bottle” capsules to track how plastic pollution travels in the Arctic marine environment.
The effort is the latest from the Plastic in a Bottle project by the Arctic Council’s Working Group on the Protection of the Arctic Marine Environment (PAME). To date, 10 GPS-equipped capsules have been launched.
The initiative is just one of many around the world sparked by concern about marine plastic pollution, because by 2050, it is estimated that the amount of plastic in the world’s oceans will outweigh the fish.
Nearly all seas and oceans are affected by marine litter, much of which reaches them via rivers. The rivers contributing the most waste are the Amur, Hai, Yellow, Yangtze, Pearl, Mekong, and the Ganges and Indus systems in Asia and the Niger and the Nile in Africa.
In addition to riverine inputs, certain extraordinary and catastrophic events — such as the April 2011 tsunami in eastern Japan — carry enormous amounts of debris into the ocean. Fishing and other marine activities are also continuous sources of specific types of litter, such as discarded nets, longlines, buoys, and tires used as boat fenders.
Nuclear tracing
The task of identifying and tracking plastic waste in the ocean is being tackled by nuclear scientists globally as part of the NUclear TEChnology for Controlling Plastic Pollution (NUTEC Plastics), an IAEA initiative launched in 2020. Using nuclear-derived imaging techniques, scientists can identify even the tiniest plastic particles in seawater, beach sand, sediment and in marine organisms.
NUTEC Plastics equips laboratories worldwide with the technology and technical knowledge required to sample, analyze, and monitor microplastic pollution in the ocean.
For example, IAEA experts from the Environment Laboratories in Monaco have undertaken sampling missions to Antarctica and to Ecuador’s Galápagos Islands to gather data and build sampling capacity in the region.
Over 100 laboratories worldwide are now connected through NUTEC Plastics Global Marine Monitoring Network, sharing data and expertise, and more than 400 scientists have been trained to monitor and analyze microplastic pollution.
Citizen science
New research published in the Journal of Cleaner Production used the power of hundreds of citizen scientists across Mexico, Central America, and South America who helped trace where the plastic bottles polluting beaches came from and what their journeys reveal about regional pollution. Working with local researchers and educators, volunteers collected bottles from beaches, rivers, and nearby islands across 10 countries.
Together, they cataloged thousands of bottles and caps. In the study, islands consistently accumulated more foreign bottles than those found on the country’s coast. Positioned in the pathways where major Pacific current converge, some islands act like natural traps, intercepting trash that would otherwise remain dispersed at sea.
The main recommendation from the study is to implement a standardized system of returnable plastic bottles that can be returned in any country and to any company.
Collection standard
Meanwhile, researchers from Kyushu University have developed a new method to more accurately analyze the distribution of small microplastics in the ocean at various depths.
Published in the journal Environmental Science & Technology, their findings showed that concentrations of small microplastics suspended in the ocean range from 1,000 to 10,000 particles per cubic meter. These particles can drift there for 20 to 40 years.
Most ocean microplastics are made of polyethylene and polypropylene. These materials are less dense than seawater, so they float near the sea surface. However, over time, algae, bacteria, and other marine organisms attach to their surface, increasing their weight so they sink towards the seafloor.
Past studies that collected small microplastics from the ocean used net tows or pumped ocean water from different depths. However, researchers still lacked a detailed view of the distribution of small microplastics at different ocean depths.
The new method developed by the Kyushu University researchers only requires about 50 liters of seawater, one to two orders of magnitude less than conventional pump sampling. Prior to this study, there was no standardized protocol to evaluate the presence of small microplastics in the ocean that could minimize contamination, particle loss, and potential fragmentation.
Data standards
Agreeing on a common methodology for obtaining and comparing data is one key part of preventing marine waste from continuing to accumulate in the oceans, says an international group of researchers in an article published in Marine Pollution Bulletin.
The integration of modern technologies such as autonomous and crewed underwater vehicles, side-scan sonar, very high–resolution multibeam bathymetry, and image analysis, has improved the processes used to identify, quantify, and categorize marine litter.
Data from the private sector could contribute to the definition of historical baselines, to scientific monitoring programs, and therefore also to the identification of long-term trends.
The study aims to raise awareness and emphasize the need to include marine litter — and particularly that on seafloors — in any directive, convention, treaty, or agreement aimed at minimizing pollution.
