The Ocean: Earth's Biggest Trash Can

As Earth's population continues to grow, the production and subsequent disposal of waste is becoming an increasingly pressing issue. Think plastic cups; they're fairly small and insubstantial objects that you probably don't spend too much time worrying about. However, just one of these can take over 50 years to decompose, so with an estimated 8 million tonnes of plastic being dumped in the ocean each year, an almost incomprehensible amount has built up since disposal in the sea first began. The biggest collection of ocean waste stretches from Japan to America and is known as the Great Pacific Garbage Patch, a diagram of which is shown in Figure 1. The extent of this patch is so large that scientists estimate it could even be bigger than the USA. 

Some of you may perhaps be wondering why there is so much waste in our oceans - don't we just put rubbish in the bin? There is in fact a host of ways by which waste can make its way into the ocean, including the mismanagement of landfill sites, shipping casualties, and quite simply littering at the coast. Whether by accident or on purpose, it is something we must try and regulate in order to reduce the damaging effects it can have on ocean life.

Figure 1: the Great Pacific Garbage Patch (National Geographic 2016)

However, dumping of plastics in the ocean is not the only component of marine pollution. Chemical waste from industry and agriculture often gets into streams and rivers which eventually wind their way to the sea, polluting it further. Once in the ocean, these chemicals can become part of the food chain and have a damaging effect on migrating bird populations. Not only does this chemical waste effect wildlife, but it can also influence climate and in fact contribute to global warming. The release of nitrates from fertilisers into the ocean can increase the production of nitrogen, a greenhouse gas, by enhancing microbial growth at the sea surface.

The impact of these chemicals will be explored in greater detail throughout this blog, as well as exactly what happens to those plastics once they have entered the ocean, besides floating from the east coast of Japan to the sunny sands of California. We'll also be looking at what plans are being made, from surfing entrepreneurs to government officials - who will find the most effective solution to help tackle the growing problem of rubbish in our seas?

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