(NaturalNews) A full 88 percent of the ocean's surface is polluted with plastic trash residue -- but this only accounts for just 1 percent of the trash that scientists currently believe to be in the ocean, according to a study conducted by researchers from the University of Cadiz, Spain, and the University of Western Australia, and published in the Proceedings of the National Academy of Sciences.
"We can't account for 99% of the plastic that we have in the ocean," researcher Carlos Duarte said.
Ocean surface coated in plastic debris
Worldwide, nearly 300 million tons of plastic are manufactured per year. According to the best estimates, about 300,000 tons of that yearly output eventually end up in the ocean.
"We are putting, certainly by any estimate, a large amount of a synthetic material into a natural environment," said Kara Lavender Law, from the Sea Education Association in Woods Hole, Massachusetts. "We're fundamentally changing the composition of the ocean."
The new study, however, is the first survey that has actually been performed to actually measure plastic waste in the ocean. It consisted of 3,070 samples taken from ocean sites around the world by the 2010 Malaspina science expedition.
Most of the plastic detected was less than a fifth of an inch long.
"Those little pieces of plastic, known as microplastics, can last hundreds of years and were detected in 88 percent of the ocean surface sampled during the Malaspina Expedition 2010," lead researcher Andres Cozar said.
While much of the plastic that ends up in the ocean was originally that size -- for example, microbeads of plastic that are used in certain toothpastes and cosmetics -- much of it originated in larger plastic items that were eventually broken apart by the action of water and sunlight.
The researchers also found that, due to the action of ocean currents, plastic tended to concentrate in five distinct areas: in the Pacific Ocean to the west of the United States, in the Atlantic between the United States and Africa, in the Pacific to the west of South America, and in the Atlantic and Indian Oceans off the coast of southern Africa.
Missing plastic poisoning fish and birds?
Although the researchers estimated that the amount of plastic currently floating on the ocean's surface may come to 35,000 tons, this is only about 1 percent of the amount that the scientists expected to find. This suggests that plastic does not, as previously assumed, mostly gather in giant floating "garbage patches."
There have been hints, before this, that much of the plastic is sinking beneath the surface, being consumed by animals, or both. Although the amount of plastic detected in oceans initially appeared to be increasing at the same rate as global plastic production, by the mid-1980s scientist observed that the amount of plastic waste in oceans had leveled off -- even though global plastic production was still increasing.
In particular, researchers found very little evidence of very small plastic pieces.
"Ocean currents carry plastic objects which split into smaller and smaller fragments due to solar radiation," Cozar said. "These microplastics have an influence on the behavior and the food chain of marine organisms."
Although no research has been done on the exact effects of plastic consumption in wild aquatic animals, studies have established that many plastics have toxic and hormone-disrupting effects. Because so many of the planet's life forms -- including humans -- live in or eat from the oceans, this could have a wide-ranging environmental impact.
"There is potential for this plastic to enter the global ocean food web," Duarte said. "And we are part of this food web."