Tiêu đề Reading Passage 02-Pollution in the oceans.pdf ✅

T h ầ y H i ệ p S Đ T : 0 9 0 6 1 1 5 1 7 1 Page 1 of 2 Mr. Hiep’s English Classes READING PASSAGE 02 Pollution in the Oceans A Everybody uses the sea directly or indirectly as a rubbish bin. Most of the substances thrown into the sea cannot be reused or broken down by nature and they cause soiling, destruction and death to the sea’s inhabitants. The marine protection organisation, Oceana, estimates that worldwide about 680 tonnes of waste are thrown directly into the oceans every hour, and more than half of this waste is made of plastic. B Between Hawaii and California, the Great Pacific Garbage Patch, an accumulation of small floating plastic pieces derived from bottle caps, carrier bags, fishing nets and so on, covers an area of the ocean’s surface as big as Western Europe. Due to its constant growth, the exact size of the Great Pacific Garbage Patch is unknown. The garbage patch developed in this area because of the North Pacific Subtropical Gyre, one of many oceanic gyres created by a convergence of ocean currents and wind. As the currents meet, the earth’s coriolis effect causes the water to slowly rotate, acting like a funnel that pulls together any rubbish that is floating in the water. The existence of a garbage patch was predicted in 1988 by the National Oceanic and Atmospheric Association (NOAA), but it was not officially discovered until 1997, because of its remote location and harsh conditions for navigation. The North Pacific gyre is one of five major ocean gyres, and it is likely that this trash vortex problem is present in other oceans as well. C Plastics can soak up and concentrate damaging pollutants, known as persistent organic pollutants (POPs), chemicals that can cause different cancers, increased infertility and brain and nervous system abnormalities. Any organism eating pieces of plastic debris will also take in these highly toxic pollutants. This leads to biomagnification, whereby the concentration of POPs increases greatly at every step in the food chain, and top predators end up with extremely high levels. Killer whales, for example, acquire the lifetime accumulation of POPs of the animals they eat. These toxins are also passed from female to calf during gestation and nursing. D In addition to these hazards, the floating plastics can also affect marine ecosystems by providing a ready surface for organisms to live on. These plants and animals can then be transported on the plastic far outside their normal environments, populating new ones and becoming possible nuisance species by interfering with the food chains or breeding pools in these new ecosystems. E Not all plastic floats; approximately 70 per cent of discarded plastic sinks to the bottom. In the North Sea, Dutch scientists have counted around 110 pieces of litter for every square kilometre of the seabed, which represents a staggering 600,000 tonnes in the North Sea alone. These plastics can smother the sea bottom and kill the marine life that is found there. A lot of this underwater rubbish comes from rivers, which also carry the rubbish underwater and is therefore unseen. The UK’s River Thames, for example, has recently undergone an experiment. Scientists used crab nets to catch underwater rubbish and retrieved more than 8,000 pieces of plastic over 3 months. All this rubbish would have ended up in the North Sea. F The idea of sea water rubbish processors being placed in the ocean to gather trash is currently under development. The processors would float on the surface of oceans and use long arms, known as "booms", to divert rubbish into the main body of the processor where small pieces of plastic debris would be filtered out of the water. The use of booms rather than net meshes would mean that even the smallest particles would be diverted and extracted, but virtually no by-catch would occur. The platforms would be completely self-supporting, receiving their energy from the sun, currents and waves. According to the inventor, reprocessing and selling the plastic retrieved by rubbish processors from the world’s gyres could potentially even be profitable. G Many campaigners against marine debris are sceptical about this suggestion, however. They point out that the size of the world’s oceans is so vast and the scope of the plastic trash problem so great that, even if they worked efficiently, processors of this type would have a negligible effect on the amount of trash in the oceans. What’s more, the sceptics say that recycled ocean plastic waste has very little commercial value, as it requires cleaning to remove sea life and toxins before it can be used. They also assert that it is extremely brittle, making it unsuitable for many of the purposes for which