The search for debris from the missing Malaysia Airlines flight has been made harder by vast amounts of floating plastic rubbish, with research showing the Indian Ocean is one of the world’s most polluted seas.
Hundreds of objects have been investigated after being spotted by the naked eye or in satellite images, with none so far deemed to have any connection with MH370.
The California-based 5 Gyres research group recently completed the first global estimate of rubbish volumes in the world’s oceans, ranking the Indian Ocean the third worst behind the North Pacific and Atlantic.
Co-founder Marcus Eriksen has traversed and studied all five sub-tropical gyres – large systems of rotating currents – travelling on a ship from Perth to Mauritius, where he saw heaps of floating garbage including fishing nets, bottle caps, disposable cutlery and buckets.
“These are massive accumulations,” Mr Eriksen said from Los Angeles.
He said the rubbish came from commercial ships losing and dumping gear overboard, dense coastal populations and catastrophic events such as tsunamis and hurricanes.
“The massive hurricane that just happened a few months ago in the Philippines produced a lot of marine trash. Same for the tsunami that hit Japan in 2011. We estimate between five and 20 million tonnes,” Mr Eriksen said.
There are massive pulses of garbage going out to the sea
Sailing from Tokyo to Hawaii 18 months after the 2011 tsunami, he saw tatami mats, shoes, toothbrushes and half a fishing boat.
“The hurricane that hit my home town of New Orleans, in Louisiana, that produced a massive 118 million tonnes of trash.
“So there are massive pulses of garbage going out to the sea.”
Rubbish also flowed from big river mouths such as the Nile, which runs through developing countries where there is little or no waste management, Mr Eriksen said.
He said it was possible that garbage found in the Indian Ocean search for MH370 could have travelled south from the Bay of Bengal, which he’d seen spew “a river of trash” to the Andaman Islands.
“Bags and dolls and flip flops – my nets were just full of waste,” he said.
“Some of that trash can cross the equator. Most of it, I assume is washing up on a beach somewhere, but some of it is slipping by.”
Mr Eriksen said rubbish moved around in the southern hemisphere between the South Pacific, South Atlantic and the Indian Ocean gyres via the Southern Ocean.
He said searchers for MH370 probably didn’t realise – until they had sifted through plenty of rubbish – that there was so much out there.
“There’s a silver lining in this tragedy … that the aircraft crash brought to light the amount of trash that’s swirling in the gyres.”
Lieutenant Commander Adam Schantz, the officer in charge of the 32 air and ground crew manning the surveillance aircraft for the search, described the objects found so far as “just garbage”.