<P> A 2017 study conducted by scientists from the University of California, Santa Barbara, and the University of Georgia, concluded that of the 9.1 billion tons of plastic produced since 1950, close to 7 billion tons are no longer in use . The authors estimate that only 9 percent got recycled over the years, while another 12 percent was incinerated, leaving 5.5 billion tons of plastic waste littering the oceans and land . </P> <P> Another recent Australian study focused on the high rate of seafloor plastic pollution, thereby highlighting an often overlooked aspect of oceanic plastic pollution . The researchers from the Institute for Marine and Antarctic Studies at the University of Tasmania stated that "while the huge volume of plastic debris accumulating in the world's oceans and on beaches has received global attention, the amount of plastic accumulating on the seafloor is relatively unknown ." </P> <P> The size of the patch is unknown, as is the precise distribution of debris, because large items readily visible from a boat deck are uncommon . Most debris consists of small plastic particles suspended at or just below the surface, making it difficult to accurately detect by aircraft or satellite . Instead, the size of the patch is determined by sampling . Estimates of size range from 700,000 square kilometres (270,000 sq mi) (about the size of Texas) to more than 15,000,000 square kilometres (5,800,000 sq mi) (about the size of Russia). Such estimates, however, are conjectural given the complexities of sampling and the need to assess findings against other areas . Further, although the size of the patch is determined by a higher - than - normal degree of concentration of pelagic debris, there is no standard for determining the boundary between "normal" and "elevated" levels of pollutants to provide a firm estimate of the affected area . </P> <P> Net - based surveys are less subjective than direct observations but are limited regarding the area that can be sampled (net apertures 1--2 m and ships typically have to slow down to deploy nets, requiring dedicated ship's time). The plastic debris sampled is determined by net mesh size, with similar mesh sizes required to make meaningful comparisons among studies . Floating debris typically is sampled with a neuston or manta trawl net lined with 0.33 mm mesh . Given the very high level of spatial clumping in marine litter, large numbers of net tows are required to adequately characterize the average abundance of litter at sea . Long - term changes in plastic meso - litter have been reported using surface net tows: in the North Pacific Subtropical Gyre in 1999, plastic abundance was 335 000 items / km and 5.1 kg / km, roughly an order of magnitude greater than samples collected in the 1980s . Similar dramatic increases in plastic debris have been reported off Japan . However, caution is needed in interpreting such findings, because of the problems of extreme spatial heterogeneity, and the need to compare samples from equivalent water masses, which is to say that, if an examination of the same parcel of water a week apart is conducted, an order of magnitude change in plastic concentration could be observed . </P>

What is the area of the great pacific garbage patch
find me the text answering this question