How to Clean the North Atlantic Garbage Patch?
Part 2: Recovery
Four Main Strategies
What requirements does our recovery need to meet in order to be feasible?
1. TECHNOLOGY: Any solution should only use technology which is currently available. No dependence on future innovations or major research and development is permitted.
2. FUNDING: Any solution needs to be able to recover and recycle ocean plastic for less than 75 cents per pound ($1.65/kg). This is how much virgin plastic generally costs. Being able to offer a competitive price compared to non-recycled materials is critical to large-scale implementation.
3. ENVIRONMENT: Any solution needs to have as little negative impact on the environment as possible. Ensuring our efforts achieve a net positive for any ecosystem we have an effect on is vital.
What recovery methods will be our main focus?
The easiest way to recycle ocean plastic is to crowdsource it. We plan on establishing plastic collection centers in dozens of countries across the North Atlantic. Locals can collect plastic from beaches, rivers, and canals and sell it to our partners where it will then be processed and shipped. This strategy has already been proven by groups like Ramase Lajan and has demonstrated the capability of each center to process 20,000 pounds of plastic a month consistently.
We want to take this concept a step further. Through hands-on training and providing locals with quality equipment, we believe we can process twice as much material per center. In a survey of participants working with these types of collection programs, the largest hurdle respondents said they had to overcome was transportation. Many have to walk miles with the plastic they recovered to reach the nearest center. Creating a pickup option is one key way to increase efficiency.
Cleaning up beaches by-hand is not a long-term solution. In order to regularly clean beaches of pollution, we’re developing a machine that acts similarly to a small mobile conveyor belt. It scoops up sand and debris as it moves along and vibrates the sand away until only the pollutants remain. Rather than a beach cleanup depending on thousands of man-hours, this machine can comfortably clean a mile-long stretch of coast in just under 24 hours while only needing two operators present. The beach sifter is being designed for use in remote areas with the ability to recharge through solar power, replace parts through 3D printing, and require little-to-no training. Most importantly, it will be compact and light, making transportation easy.
Another simple solution we are designing is a thick rubber net to be placed in rivers and canals. The net extends into the water, catching the majority of floating debris which would otherwise empty into the ocean. It will not interrupt the flow of the river or trap marine life. After the net becomes full, it can easily be raised up and swung over to be emptied into an open shipping container placed on the side of the river. Once the container is full, this material can be taken straight to a processing facility. This machine requires no electricity and can also have most of its parts replaced through 3d printing.
Drone Recovery Fleet
There have been dozens of highly-publicized ocean-cleaning drone concepts over the years: Drone 1-001-1 by Elie Ahovi, The Ocean Cleaning System by Erik Borg, Cesar Harada’s Project Protei, The Pod Project by the Abundant Seas Foundation, and Project Floating Horizon by Ralph Schneider. They all face the same short-coming, they all depend on drones doing something they’re bad at: improvising. Searching for plastic in the ocean, capturing it, and returning to a ship all while avoiding marine life requires an insanely flexible machine. When many of these concepts were originally created drones weren’t capable of doing these tasks yet and they still aren’t today. Because of these failed droned concepts, many ocean-cleaning solutions have discarded using drones altogether. We believe using drones is a huge advantage in large-scale projects like ocean-cleanup, but we need to give them tasks they already excel at like reconnaissance and pattern recognition.
We have outlined how we plan to make significant impacts in beaches, rivers, cities, and rural areas, but the garbage patch will continue to grow if nothing is done about it directly. How we plan to deal with the cleaning of the NAGP itself is by sending out large ships equipped with dozens of drones. These drones scouts will fly over the surrounding ocean taking aerial 4K video of the surface. When they return to the ship, they begin recharging, and sync their data back to the ship’s computers. These computers, having been trained to look for ocean debris in the drone’s video, create a local map of exactly where any large objects (100 cm<) or large concentrations (100kg per 1 sq km) are. If a significantly large target is spotted, then the ship redirects to that area for recovery.
The above chart is a breakdown of the depths at which ocean plastic can be found. The majority of the NAGP is made up of material floating near the surface; 60% of it can be found in the first meter and 75% in the first two. Drones will be able to see this material and track it effectively.
These kind of drone ships are easily scalable; one is able to operate on its own and as a group they can cover more ground and work together to recover larger targets. Current drone technology already allows for a range of 4 miles and 4K video is available through consumer drones like the DJI Mavic 2 Pro ($1,499).
The most densely polluted section of the North Atlantic Garbage Patch is roughly 1/6th of its total size: 971,244 square miles (Source). Through some simple math, we can calculate that each drone ship should be able to map 640 square miles a day, assuming 8 hours of usable sunlight and a slow speed of 9 knots (10.36 mph). With a fleet of only 7 ships, the entire core can be covered in 7 months. However, this doesn’t account for many factors like actually retrieving the ocean plastic and weather conditions. There’s no doubt that the time spent retrieving the debris will add on months. Limiting the recovery effort to better sailing seasons like the early summer and avoiding fall hurricanes is a necessity as well, despite prolonging the cleanup. The end result will be a fleet of 7 drone ships recovering ocean plastic over 3-month sessions. The majority of the NAGP can be mapped and its plastic recovered in the first 5 of these sessions.