Only around 13 per cent of the world’s oceans can still be classified as wilderness, according to a new study published in the journal Current Biology. The wilderness areas that do remain are unevenly distributed across the Arctic, Antarctic and waters around Pacific Island nations.
Well-preserved wilderness areas contain high levels of biodiversity and are some of the last places on Earth where apex predators can be found. In coastal regions, there is almost no marine wilderness left at all.
In the study, lead researcher Kendall Jones of the University of Queensland and his team analyzed global data on 19 man-made stressors – including commercial shipping, fertilizer and sediment runoff, and ocean fishing.
The scientists then mapped the world’s marine wilderness by identifying areas with very little impact from 15 anthropogenic stressors and a low cumulative impact from these forces. To be classified as ‘wild’, an area has to be almost entirely free of human disturbance.
"We were astonished by just how little marine wilderness remains," says Jones. "The ocean is immense, covering over 70 per cent of our planet, but we've managed to significantly impact almost all of this vast ecosystem."
The data ultimately showed that the degree of man-made damage varies across different regions. More than 16 million square kilometres of wilderness still exists in the Indo-Pacific Ocean, accounting for some 8.6 per cent of its total composition.
The situation is worse in the temperate area off southern Africa, where there is less than 2,000 square kilometres of marine wilderness left, amounting to under 1 per cent of the ocean. Less than 5 per cent of all remaining marine wilderness is protected.
"This means the vast majority of marine wilderness could be lost at any time, as improvements in technology allow us to fish deeper and ship farther than ever before," Jones explains. "Thanks to a warming climate, even some places that were once safe due to year-round ice cover can now be fished."