Science matters
Plastic litter washed up on a beach in Singapore.
The ‘Plastic Plague’ – a threat to the oceans Richard Harwood examines a concerning blight
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rising mass of plastic debris being dumped, blown or simply washed out to sea, and it is having a deleterious impact on the marine environment. Data from the 1960’s show that slightly fewer than 5% of sea birds would be found then with waste plastic fragments in their stomach. Today this figure is of the order of 90% and, on current trends, it is estimated that by 2050 plastic ingestion will reach 99% of the world’s seabird species, with nearly every individual bird affected. Other marine species such as sea turtles also suffer harmful effects from plastic waste. Ingested plastic litter is impossible to digest and takes up space in the stomach or gizzard that otherwise should be used for food. Alternatively, it can cause an obstruction that starves the bird directly. Studies of birds in the North Pacific have shown that ingestion of plastics results in declining body weight and body condition. The use of the term ‘garbage patch’ is controversial and Summer |
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The oceans, and life within them, face a number of threats in this modern age. Acidification from dissolved carbon dioxide is becoming an increasing problem, potentially altering the patterns of algal life along our shorelines and causing the blighting of coral reefs. A further problem is the accumulation of various forms of plastic detritus, discarded on land but finding its way into the sea. It washes up on urban beaches and remote islands, tossed about in the waves and transported across incredible distances before arriving, unwanted, back on land. There is a lot of plastic in the world’s oceans. It accumulates into great floating ‘garbage patches’ that cover large swathes of the Pacific. Such accumulations of waste are associated with the ocean gyres, of which there are five – the North Atlantic, South Atlantic, North Pacific, South Pacific, and Indian Ocean gyres – created by global wind patterns and the rotation of the Earth. Numerous studies have now catalogued the
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