THIS is going to be a busy week for us conservationists. This Thursday, June 5, is World Environment Day and this Sunday, June 8, is World Oceans Day. Today is to be celebrated of course, although we should celebrate the natural environment every day, but I thought I might concentrate on the world’s oceans and their plight. World Oceans Day was a Canadian proposal at the United Nations Earth Summit in Rio de Janeiro, Brazil, in June 1992, and it has been marked ever since.
The biggest problem with the world’s oceans is that we see them as limitless.After all, they cover 71 percent of the planet’s surface, contain 97 percent of its water and just seem to go on forever. From The Hide the sea’s horizon is about 18 kilometres away and beyond that lie the seemingly boundless reaches of the Indian Ocean, the next land is Australia. The Atlantic is even bigger and the Pacific the biggest of all. And yet we have managed to fill them all with rubbish.
The world’s great oceans all have an interconnected system of currents, a separate system in each ocean, but connected to the next. In each of the oceans the currents create vortexes, a system of circulating air and water known as a gyre. There is one huge gyre in the North Atlantic, another in the south, one in the North Pacific and another in the south, and one in the Indian Ocean, mainly between Madagascar and Australia. Those in the northern hemisphere rotate clockwise, those in the south, including the one in the Indian Ocean, rotate anti-clockwise. Like all vortexes, these gyres collect things, notably rubbish.
This rubbish consists of both natural material, but more importantly the rubbish that we humans generate in vast quantities. Most of it is plastic, because glass tends to sink (thus polluting the ocean floor), metal simply rusts away in time, and rubbish with a natural base, like wood or paper, eventually rots away. So, we’re left with plastic, which lasts forever. The plastic is a disaster for marine life in many different ways, from being caught in it to trying to eat it. These gyres also collect bacterial and chemical pollution, which again is a disaster for marine life.
The rubbish that ends up on our beaches, usually washed down from the hinterland by the rivers or simply dumped directly on the beach, is likely to end up in a gyre, and by the same token, spin-offs (literally) from gyres end up on the beaches. It’s a vicious circle (pardon the pun).
An interesting side story: aircraft and ships searching for the missing Malaysian Airlines flight MH370 kept on finding flotsam which they thought might be wreckage of the airliner. It never was however, but rather bits of wreckage from the Indian Ocean gyre.
So, we’ve even managed to make a mess of the world’s vast seas, something to remember on World Oceans Day. Cheers!
Source: Discovery News.
