How to Clean the North Atlantic Garbage Patch?

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Part 1: Overview

A Detailed Look at the Problem

Our trash accumulates in 6 main areas around the world, referred to as garbage patches. These are largely made up of plastics which breakdown over years, impacting ecosystems and hurting the planet. While the largest of these patches is in the North Pacific, it represents only part of the problem. There are other swirling masses of plastic pollution in the South Pacific, North & South Atlantic, and Indian Oceans, as well as in the Mediterranean Sea; a long-term solution will need to address all of these regions.

Why are we choosing to focus on the North Atlantic’s ocean plastic first?

The North Atlantic has something no other garbage patch has: choke points. The Caribbean Islands act like a funnel, forcing ocean plastic to pass through small channels. Rather than concentrating our cleanup efforts in the middle of the garbage patch, we can take advantage of these choke points and place our recovery infrastructure where it can be the most effective. The three main choke points that Atlantic currents pass through are: 1. Yucatan-Cuba, 2. Florida-Cuba, and 3. Florida-Bahamas.

The North Atlantic Garbage Patch, usually referred to as the NAGP, is also surrounded on all sides by relatively close land. North and South America, Africa, and Europe are all nearby. This is in contrast to the North Pacific’s garbage patch which only has the island chain of Hawai’i. When material is recovered from the NAGP, it can immediately be shipped to processing facilities on any of the 4 surrounding continents.

This is a map of Atlantic currents demonstrating how the Caribbean guides ocean waves into a few key passages near the Southern United States. Source: https://earth.nullschool.net/#current/ocean/surface/currents/overlay=currents/orthographic=293.57,22.31,862

What are these garbage patches actually made of?

Using the most recent scientific publications, we’ve been able to construct a model of what we expect to find in the North Atlantic. The current estimate is that the NAGP contains approximately 125 million pounds of plastic spread out over millions of square miles (Source).

Source: Based on a hybrid model of data provided by the Lebreton, Maximenko, and Van Sebille simulations

The NAGP is made up of 99.9% plastic (Source). Although pollution near coastlines consists of a wide variety of materials such as cigarette butts, glass, and cardboard, the only types of pollution able to stay intact in the ocean are durable plastics. As can be seen in the chart below, the North Atlantic’s pollution is almost entirely made up of Polyethylene (PE) and Polypropylene (PP) plastics, two widely-used and easily-recycled polymers. There are trace amounts of Polystyrene (PS) and Polyvinyl Chloride (PVC) present as well.

Source:  https://www.nature.com/articles/s41598-018-22939-w  P. 9; Supplementary Table #3, P. 25

Source: https://www.nature.com/articles/s41598-018-22939-w P. 9; Supplementary Table #3, P. 25

When we think about what makes up the NAGP, focusing on weight rather than individual pieces is more productive for the recovery effort due to the difficulty in targeting objects smaller than a few centimeters. The largest group of debris, pieces larger than 50 centimeters, make up 53.68% of the total weight. And even though microplastics represent nearly 95% of the pieces identified, they only account for 0.77% of the total weight.

Ocean Plastic By Size Range

Where is all of this ocean plastic coming from?

Unlike how the Pacific Ocean’s plastic pollution is regularly attributed to Eastern Asia, the North Atlantic’s is a shared problem with significant contributions originating from every bordering country.

In total, 70 countries directly contribute to the North Atlantic Garbage Patch. The highest polluters typically have factors in common, either being small island nations or having their populations compacted near coastlines. Brazil (Ranked: #2) and Morocco (Ranked: #3), for example, have inhospitable interiors (i.e. jungles, deserts, etc.) which have prevented their populations from spreading inward.

The largest contributor is Nigeria, which has both a waste management problem as well as one of the fastest growing populations of any country. Its capital city of Lagos, population 21 million, is the most significant pollution source in the country, in addition to the extensive river systems like the Cross, Imo, and Kwa Ibo (Source).

In a recent study, coastal populations were identified as the largest source of ocean plastic accounting for nearly 60% of the NAGP. Inland populations, farther than 50 km from a coast, are also a concern; however, rivers are much easier to clean compared to open oceans making implementation of solutions much faster and cheaper. Fishing pollution represents 28.1% of the total and can be broken down into subcategories of fishing, aquaculture, and shipping. As a broad generalization, the plastics that come from population centers (coastal and inland sources) are typically consumer plastics like single-use bottles which breakdown rather quickly to become the microplastics in the NAGP while the plastics originating from marine sources (fishing, shipping, and aquaculture) usually make up the megaplastics category, these hardly degrade at all and need to be recovered manually.

Source:  https://www.nature.com/articles/ncomms15611 ; Supplementary Table #6, P. 28

Source: https://www.nature.com/articles/ncomms15611; Supplementary Table #6, P. 28

Part 2: Recovery

Part 3: Recycling

Part 4: Projection