By Carl Nettleton
Founder
OpenOceans Global

Plastic, from lost fishing gear and land-based sources, significantly impacts the marine environment. Plastic production, waste and leakage into the ocean are expected to double, even triple, in the coming decades, with 11 million metric tons now reaching the ocean annually.

Emerging news about impacts on human health has raised new concerns, with findings that microplastics are seemingly everywhere in our bodies, food and water, and that many plastics contain toxic chemicals. More than 16,000 types of chemicals have been found in plastic, many untested for toxicity. More than 4,200 plastic chemicals are of concern because they are persistent, mobile, toxic and/or bioaccumulate.

One key misperception has disempowered the public from coalescing to find solutions: the belief that most ocean plastic has accumulated into an “island” in the northern Pacific the size of Texas. This is not accurate: 75 percent of ocean plastic is actually on beaches or other shorelines, and most of the rest is in coastal waters.

Technology plays an important role in addressing ocean plastic pollution. An estimated 640,000 metric tons of fishing gear is lost or discarded in the ocean annually, including lines, buoys, nets, pots, traps and floats. Much of it is constructed from plastic. In addition to trashing shorelines, particularly those of island nations, ghost fishing by lost gear has long been a problem. One new technology alerts fishers when a fishing line detaches from its buoy or submerges deeper than intended. The alert allows the equipment to be retrieved before it is lost. Other technologies can track fishing gear by satellite after it is lost.

Rivers bring the majority of plastic to the ocean. The Ocean Cleanup nonprofit has had early success capturing plastic in rivers using its Interceptor technology. The Interceptor is a boom extending across large rivers. The river’s flow guides plastic trash along the boom to a barge, where a conveyor belt and shuttle distribute the debris across six dumpsters. When the dumpsters are almost full, it sends a text message to the operator, who moves the barge to a dock, empties the dumpsters, sends the debris to waste management facilities, and returns the barge to the Interceptor.

The Ocean Cleanup has three other technologies deployed in rivers: a smaller unit tending a trash boom, a standalone barrier to capture plastic coming down smaller rivers, and a barrier specifically suited for shallow waters.

Several other plastic barrier technologies have also been developed. A group in Indonesia called Sungai Watch is regularly cleaning 100 rivers by deploying its custom booms in conjunction with teams of workers. The group has expanded its activities to train villagers to stop throwing plastic into local rivers, giving them other options for disposal. A Dutch company makes bubble curtains that stop trash from flowing downriver in slow-moving waters.

Drifters are being deployed that simulate how plastic debris moves across the ocean to identify sources of plastic geographically. ROVs and AUVs are used to conduct surveys to find debris in the water column or on the seabed. Both remotely operated and autonomous equipment are being used to scoop up floating plastic debris in coastal waters.

Finding plastic hotspots is becoming a priority. Remote sensing by satellite, airplane, and drone is used to locate plastic on shorelines and in ocean waters. Ideally, satellites could provide a global assessment of the status of plastic along coasts and on surface waters, but satellite imagery still lacks the resolution to identify plastic debris such as soda bottles and wrappers. Hyperspectral imaging using drones thus plays a role in mapping the extent and concentration of microplastic pollution.

Even when accumulations of plastic are found, the challenge of disposal remains. There are only three options: landfilling, incineration and recycling. Many small, low-lying nations don’t have suitable locations for landfills. Environmental groups frown upon incineration, but many residents living on islands or in developing countries have little or no access to waste management collection or landfills. They often resort to open burning or dumping plastic into rivers. Recycling is a growing option, but with less than 10 percent of plastic recycled globally, the infrastructure to improve recycling rates will not expand quickly enough to make much of a difference in the near future. Chemical recycling, a process to break down plastic into raw materials for new products, is being explored but is strongly opposed by environmental groups.

In March 2022, the United Nations Environment Assembly adopted a historic resolution to develop an international legally binding treaty on plastic pollution, including in the marine environment. It requested the UN Environment Programme to convene an Intergovernmental Negotiating Committee (INC) to develop a treaty to address the full life cycle of plastic, including its design, production and disposal. After a rocky start, with little progress in the first three sessions, the INC completed the actual text to start treaty negotiations.

The fifth and final negotiating session concluded in December 2024 with no agreement, other than to meet again in the summer of 2025. The primary obstacle was whether to include caps on plastic production. Oil-producing countries, led by Saudi Arabia and including Iran, Russia and other Gulf states, oppose caps. The U.S. took a neutral stance.

If the treaty is finally adopted, its substantive elements will likely address chemicals of concern, problematic product design and financing to implement the treaty. The most important element of the treaty will likely be a framework, as with the Paris Climate Agreement, that calls for an annual gathering of the participating countries to assess new science and make incremental changes in the agreement.

It remains to be seen if and how the global plastics treaty will take shape.

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