(Courthouse News Service) Only a small fraction of the world’s oceans can still be classified as wilderness, according the first systemic analysis of global marine wilderness published Thursday.

About 13 percent of the world’s oceans remain marine wilderness. What is left is primarily found in the Arctic, the Antarctic and around remote Pacific Island nations. Almost none exists in coastal regions.

“We were astonished by just how little marine wilderness remains,” Kendall Jones of the University of Queensland, Australia, and the Wildlife Conservation Society, said. “The ocean is immense, covering over 70 percent of our planet, but we’ve managed to significantly impact almost all of this vast ecosystem.”

Rapid declines in wilderness on land have been well documented, while much less was known about the status of marine wilderness prior to this study, researchers said. These areas are crucial for marine biodiversity.

“Pristine wilderness areas hold massive levels of biodiversity and endemic species and are some of the last places of Earth where big populations of apex predators are still found,” Jones said.

The study, published in Current Biology, also shows that less than 5 percent of global marine wilderness is currently protected. Offshore ecosystems are protected most, while high-biodiversity areas such as coral reefs enjoy the fewest protections. Despite holding high genetic diversity and endemic species, wilderness areas are ignored in global environmental agreements, according to the study.

“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 explained. “Thanks to a warming climate, even some places that were once safe due to year-round ice cover can now be fished.”

Researchers point to their findings as an urgent call for action to protect what remains of marine wilderness. Such an effort will require international environmental agreements to recognize the unique value of marine wilderness that also sets targets for retention, scientists state.

“International policies are often blind to the benefits that flow from intact, functioning ecosystems, and there is no text within the Convention on Biological Diversity or the United Nations World Heritage Convention that recognizes the importance of retaining large intact landscapes or seascapes,” the report says.

“Similarly, national-level conservation plans tend to focus on securing under-pressure habitats or endangered populations, rather than multifaceted strategies that also focus on wilderness protection.”

In conducting the study, Jones and his colleagues used the most comprehensive global data available for 19 human stressors, including commercial shipping, fertilizer and sediment runoff, and several types of fishing in the ocean, plus their cumulative impact. They systematically mapped marine wilderness globally by identifying areas with very little human impact and also a very low combined cumulative impact from these stressors.

In order to capture differences in human influence by ocean regions, the researchers repeated their analysis within each of 16 ocean realms. They found wide variation in the degree of human impacts.

The researchers excluded climate change variables because they are widespread and unmanageable at a local scale from the individual stressors, but included them in cumulative impact analysis.

Australian Government Research Training Program Scholarships, a University of Queensland Centennial Scholarship and an ARC Laureate Fellowship, funded the analysis. Current Biology is a bimonthly journal that features papers across all areas of biology.