A high-seas mission departs from San Francisco next month to map and explore a sinister and shifting 21st-century continent: one twice the size of Texas and created from six million tonnes of discarded plastic.
The toxic soup of refuse was discovered in 1997 when Charles Moore, an oceanographer, decided to travel through the centre of the North Pacific gyre (a vortex or circular ocean current). Navigators usually avoid oceanic gyres because persistent high-pressure systems — also known as the doldrums — lack the winds and currents to benefit sailors.
Mr Moore found bottle caps, plastic bags and polystyrene floating with tiny plastic chips. Worn down by sunlight and waves, discarded plastic disintegrates into smaller pieces. Suspended under the surface, these tiny fragments are invisible to ships and satellites trying to map the plastic continent, but in subsequent trawls Mr Moore discovered that the chips outnumbered plankton by six to one.
In June the 151ft brigantine Kaisei (Japanese for Planet Ocean) will unfurl its sails in San Francisco. Project Kaisei’s flagship will be joined by a decommissioned fishing trawler armed with specialised nets.
The UN’s environmental programme estimates that 18,000 pieces of plastic have ended up in every square kilometre of the sea, totalling more than 100 million tonnes. The North Pacific gyre — officially called the northern subtropical convergence zone — is thought to contain the biggest concentration. Ideal conditions for shifting slicks of plastic also exist in the South Pacific, the Indian Ocean and the North and South Atlantic, but no research vessel has investigated those areas. If this exploratory mission is successful, a bigger fleet will depart in 2010.
– from timesonline. 2 May 2009.