Only 13.2 percent of the world's ocean waters are still in their natural 'wild' state and remain unspoiled by human activity, according to a new report.
Kendall Jones, author of the report published in science journal Current Biology said: "We were very surprised by how little is left of marine nature. The ocean is immense and covers more than 70 percent of our planet, but we have managed to significantly affect almost all of this vast ecosystem."
Researchers from Australia's Queensland University systematically mapped the effect of 15 different human 'stressors' on the ocean using global available data, including commercial shipments, fertilizers and sediment run-offs, demersal fishing and other kinds of pollution.
Mapping all these factors and calculating their accumulative impact showed that only about 55 million square kilometers of ocean have been little affected by human activity with less than 10 percent impact.
The report, entitled 'The Location and Protection Status of Earth's Diminishing Marine Wilderness,' shows that unspoiled ocean zones are "unequally distributed" among the 16 different oceanic regions, located mainly in remote zones of the Pacific Ocean, the Arctic and Antarctica.
Some oceans show more evidence of human activity than others. The Indo-Pacific Ocean includes 16 million square kilometers of wilderness, amounting to 8.6 percent of its waters.
Meanwhile, there are only 2,000 square kilometers of wild ocean left in the temperate waters south of Africa: less than 1 percent of its waters.
According to the report, less than 5 percent of the world's 'wild' ocean is currently under legal protection.
Such areas "contain high genetic diversity, unique functional traits, and endemic species; maintain high levels of ecological and evolutionary connectivity... may be well placed to resist and recover from the impacts of climate change," said Jones.
They are also "some of the last places on Earth where there are still big populations of super-predators. This means that the great majority of marine wilderness areas could be lost any time, as improvements in technology allow us to fish more deeply and send ships further than ever."
The findings, according to the authors, highlight the need for "urgent action" to protect what's left of our marine ecosystems, requiring "international environmental agreements to recognize the unique value of marine wildlife."