The issue of plastic waste in the oceans has been the focus of public attention for some time now. Especially microplastics often are discussed. Many NGOs (independent and internationally active, non-profit organizations) have dedicated themselves to protecting and preserving the oceans. Their work helps to clean the lakes, rivers and the world’s oceans from pollution and to protect rare and endangered animal and plant species. A well-known and successful organization that pursues these goals is the Dutch company “The Ocean Cleanup”. More specifically, this project helps removing marine litter from the oceans and rivers using innovative processes and techniques.
Rivers in particular, are the main contributors to transporting garbage into the oceans. According to recent estimates, the world’s rivers discharge up to four million tons of plastic waste into the sea every year. Scientific studies state, that the Yangtze River carries the most waste into the oceans: It flows from the highlands of Tibet via the megacities of Chongqing and Shanghai into the East China Sea. Even at our doorstep, some larger and wider rivers, such as the Rhine, contribute to the discharge of waste into the sea. Especially rivers that pass through densely populated areas often carry high amounts of waste.
Plastic waste is increasingly being dumped in waters by private households or industries. Currently, a gigantic floating garbage mat has formed on the surface of the ocean between Hawaii and California, the so-called “Great Pacific Garbage Patch”. It extends over an estimated 1.6 million square kilometers. According to these numbers, the garbage patch is about three times the size of France. The Ocean Cleanup has already successfully tested methods to collect the garbage: by using two trawlers, a large catch net is pulled through the sea on the water surface. At the end of the net, the captured garbage is collected, while marine animals still have the chance to escape through an opening. As soon as the collection system, named “System 002”, is filled, it is loaded on board of the trawlers and brought ashore.
Surface runoff from heavy rainfall also carries waste from populated areas into adjacent rivers that flow into the sea. The Ocean Cleanup therefore is trying to solve the problem at its core by interfering at the mouths of the rivers.
The method used and developed by The Ocean Cleanup for this mission is called the “Interceptor”. It is an automated, solar-powered, stationary waste collection boat that anchors in the middle of a river and collects the washed-up and floating waste in containers. However, not all rivers are the same: Flowing waters in various parts of the world display distinctive characteristics, for example concerning the depth, width, flow velocity, or the influence of tides. The Ocean Cleanup plans to deploy interceptors in the one thousand dirtiest rivers by 2025 worldwide. Boats 003, 005 and 006 have already been built and are waiting to be deployed in Vietnam and Malaysia.
The Ocean Cleanup conducts another innovative river cleaning mission in Jamaica: A new method is currently being tested in Kingston to collect plastic waste at particularly narrow and shallow river outfalls. At this location, there are a total of eleven smaller rivers and drainage canals, which discharge an estimated 947,000 kg of plastic into the Caribbean Sea every year. Together with the non-profit organizations “Grace Kennedy Foundation” and “Clean Harbours Jamaica”, the Interceptor Barrier and the Interceptor Tender are in operation at three of these estuaries. The Interceptor Barrier is a U-shaped barrier, attached to floating pontoons that collects the garbage washed up at the river mouth. The Interceptor Tender is a garbage collecting boat, developed in cooperation with BERKY, which acts as a waste extraction tool. It easily collects the garbage step by step from the accumulated waste patch, caught inside the barrier and transports it to the shore. The 6520 weed collecting boat from BERKY forms the basis for the Interceptor Tender. In detail, the boat uses a conveyor belt which is extending into the water and picks up the refuse floating on the water surface and collects it on the loading area of the boat. At shore, the conveyor belt can transport the collected waste from the loading area to the mainland. Due to its high mobility, the waste collecting boat can be flexibly deployed at different locations. Once this method has been further tested and proven, the Interceptor Barriers and Interceptor Tender boats will be deployed at all eleven river discharge sites in Kingston, Jamaica.
In an effort to demonstrate alternative ways, in which the collected material can be used, The Ocean Cleanup sells designer plastic sunglasses, which are 100% made from the collected marine litter.
The Dutch orginization aims to further improve existing processes, increase its range of suitable methods and works on additional innovative ways to keep the world’s waters clean. Building on established products, expertise and knowledge, the partnership with BERKY allows to use existing technology that can be creatively used and repurposed.
Photos: The Ocean Cleanup
The Interceptor Barrier catches the washed-up rubbish, which is collected by the Interceptor Tender. The boat is based on the BERKY rubbish collection boat type 6520.