Author: Afreen Ahmed
Oceans clearly play an essential role in life on Earth, yet because of their vastness, humans tend to use their waters as dumping grounds for many waste materials. This practice has increased as land areas for such wastes diminish. Oceans also receive all of the pollutants that are fed to them by the rivers of the world. Even when ships are not actively engaged in dumping wastes, they are themselves sources of pollution, most notably, the giant tankers that have caused numerous massive oil spills.
As a result, by the late 20th century, ocean studies indicate that what had once been thought impossible is now becoming a reality. The oceans as a whole are showing signs of environmental pollution. Even the surface waters of the oceans are increasingly plagued by obvious litter. Some of this litter washes ashore to render beaches unsightly, while other such debris entangles and kills many sea birds and mammals every year.
More insidious than these litter problems are the effects of toxic contaminants from wastes that are dumped in the ocean. These chemicals can upset delicate marine ecosystems as they are absorbed by organisms all along the food chain. Even the paints that are being used on many ships can be hazardous.
The need to address the matter of ocean pollution has been recognized at national and international levels. According to the UN, about 8 million tonnes of plastic waste is dumped in the seas annually. It has been discovered at the deepest point of ocean, in Mariana Trench in the western Pacific Ocean. Scientists now believe “plastic is literally everywhere.” The reason why it is so difficult to clean the existing plastic from the ocean is because of the sheer amount of trash that currently exists.
So the idea of attempting to “clean up” the ocean is a quixotic one. Can these projects really make a difference?
The answer is yes, but not as expected.
Smaller technical solutions can make an impact in a localised area. Two rubbish-sucking Seabins were recently installed in Sydney’s Darling Harbour. The devices suck in water, trapping rubbish in a mesh bag, and recirculate the water back into the environment. There are 450 Seabins in 26 countries around the world, in 60 harbours throughout the US, Europe, and now the Asia-Pacific, collecting on average around 4kg of marine litter a day – or about 1.4 tonnes a year.
Another local installation, known as Mr Trash Wheel, is making a difference in Baltimore’s Inner Harbour, on the US’s north-east coast. As the wheel turns, it collects litter from the harbour and stores it in a barge for later removal. These are good examples of small-scale clean-ups that can have a local impact. What these clean-up projects are good at is increasing awareness of the plastic problem. The real goal is to stop plastics from entering the water in the first place.
However, that can’t be extrapolated to the open ocean or the global plastic crisis. What we really need is policy change, and behavioural change, and that’s just starting to happen.
Things have changed rapidly in the last 12 to 18 months, the announcement of enormous bans on single use plastics and microplastics, with countries banning single-use plastic bags worldwide, and fast-food giants committing to phase out plastic straws in their stores.
No matter how insignificant it seems, the world could see very real impacts for the health of the ocean and the broader health of planet.