The great Pacific garbage patch, which has increased in size with each decade, is mysteriously disappearing. A new study states that as much as 99 percent of plastic trash in the ocean cannot be found. The cause of the disappearance is unknown, but researchers fear the possibility that plastics are entering the global ocean food web.

At least 300 million plastic products are produced each year. Based on the estimation done by a 1970s National Academy of Sciences study, it is said that 0.1 percent (around 45,000 tons) of all plastic washes into the oceans from land, with rivers, floods, storms - and, at times, maritime vessels - carrying and contributing the refuse. 

In order to understand the size and extent of the ocean's garbage problem, a research team from the University of Cadiz, Spain, travelled across the globe in a ship called the Malaspina in 2010. They measured the plastic concentration in the water samples they collected and examined data from several other expeditions. In all, they analyzed a total of 3,070 samples.

Given the fact that plastic production has increased since 1970s, researchers expected an increase in millions of tons of ocean-born garbage. However, they found that just 7,000 to 35,000 tons of plastic debris floating in the oceans.

"We can't account for 99 percent of the plastic that we have in the ocean," Carlos Duarte, an oceanographer at the University of Australia in Crawley, told Science Magazine.

The team theorized the plastic is sinking deep in the ocean, which may be good for wildlife such as seabirds, sea turtles and seals who mistakenly consume the plastics. Or possibly, small fish are breaking down floating plastic to smaller pieces that makes it easier for marine life to eat the debris.

But Duarte explains that if fish are eating the particles, "There is a potential for this plastic to enter the global ocean food web. And we are part of this food web."

The findings were published in the journal Proceedings of the National Academy of Sciences.