Technologies implemented for cleaning the oceans from garbage
Our oceans are threatened by three major challenges: climate change, overfishing, and pollution. Plastic pollution is of growing concern and has gained international attention from governments, media and large sections of the public, partly fuelled by last year’s BBC documentary Blue Planet II and its images of sperm whales and seabirds entangled or ingesting plastic debris.
Despite the attention plastic pollution has received, some scientists think this is the least important of the major marine threats, and that climate change and fisheries need more urgent attention.
This is not to say that plastic is not a major issue – it is, especially in some parts of the developing world, and in large open ocean gyre systems where ocean currents meet and all that they carry accumulates. Research has also found that microplastics (small fragments which form as larger plastic pieces are broken down in the sea) are found in seafood, and plastic may even accumulate as it passes up the food chain.
The Ocean Cleanup
One reason why plastic pollution seems to get more attention than other threats to the ocean is that the issue may have a technological “fix”. The Ocean Cleanup is the flagship tech solution to marine plastic and proposes using several 600-meter long barriers to float in the ocean current and catch plastic drifting in the surface waters of the gyres.
Invented by a then 19-year-old student, the idea has come in for criticism in recent years with concerns ranging from the project’s ability to reach microplastics to it causing harm to wildlife.
Nevertheless, the Ocean Cleanup has captured imaginations by trying to reverse the problem of ocean plastic on a large scale.
We’re familiar with the idea that we can all do something to prevent plastic from ending up in the sea, such as refusing plastic straws and carrying a refillable water bottle. However, while we need to use less, we also need to produce less and throw away less of it. This means not only individual behavior change, but changes in industrial processes, and government policies worldwide.
CREATE A COASTLINE WHERE THERE ARE NONE
The challenge of cleaning up the gyres is that plastic pollution is spread across millions of square kilometers and travels in all directions. Our cleanup technology has been designed to do the hard job of concentrating the plastic first before it can be effectively removed from the ocean.
The system consists of a long floater that sits at the surface of the water and skirt that hangs beneath it. The floater provides buoyancy to the entire system, while the skirt prevents debris from escaping underneath and leads it into the retention system, or cod end. A cork line above the skirt prevents overtopping and keeps the skirt afloat.
TAKE ADVANTAGE OF NATURAL OCEANIC FORCES
For an area of this size, active cleanup methods would be too energy-intensive; this is why we have chosen a passive design. The cleanup systems rely on natural forces to navigate the patches – a feature that also increases its survivability in the harsh ocean environment.
Both the plastic and system are being carried by the wind, waves, and current. However, to catch plastics there needs to be a difference in speed between the system and the plastics. Using a sea anchor to slow down the system, plastic can be retained and captured.