A Real Eye-Opener. Man's Rapacious Destruction of Our Oceans.

Think of it this way. When the world's oceans die, we die. Life on Earth depends on the viability of our oceans.

This graphic depicts what little wilderness remains of the world's oceans, the parts denoted in blue.

A new paper published in the journal, Current Biology, finds that just 13 per cent of the world's oceans qualify for the wilderness designation. And just 5 per cent of that 13 per cent lies within marine sanctuary zones.

 
As human activities increasingly threaten biodiversity [1, 2], areas devoid of intense human impacts are vital refugia [3]. These wilderness areas contain high genetic diversity, unique functional traits, and endemic species [4, 5, 6, 7]; maintain high levels of ecological and evolutionary connectivity [8, 9, 10]; and may be well placed to resist and recover from the impacts of climate change [11, 12, 13]. On land, rapid declines in wilderness [3] have led to urgent calls for its protection [3, 14]. In contrast, little is known about the extent and protection of marine wilderness [4, 5]. Here we systematically map marine wilderness globally by identifying areas that have both very little impact (lowest 10%) from 15 anthropogenic stressors and also a very low combined cumulative impact from these stressors. We discover that ∼13% of the ocean meets this definition of global wilderness, with most being located in the high seas. Recognizing that human influence differs across ocean regions, we repeat the analysis within each of the 16 ocean realms [15]. Realm-specific wilderness extent varies considerably, with >16 million km2 (8.6%) in the Warm Indo-Pacific, down to <2 4.1="" 4.9="" africa.="" aimed="" also="" and="" area="" as="" at="" be="" biodiverse="" biodiversity="" br="" conserving="" continue="" coral="" ecological="" ecosystems="" ensuring="" estate="" evolutionary="" global="" holds="" in="" incorporated="" into="" is="" km2="" large-scale="" little="" marine="" now="" of="" only="" proactive="" processes="" protected="" realm-specific="" reefs.="" retention="" should="" show="" southern="" strategies="" such="" temperate="" that="" the="" very="" we="" which="" wilderness="">

Those vast white expanses? That's where anthropogenic, i.e. man-made, impacts dominate.  From The Guardian:

Huge fishing fleets, global shipping and pollution running off the land are combining with climate change to degrade the oceans, the researchers found. Furthermore, just 5% of the remaining ocean wilderness is within existing marine protection areas. 

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

Jones said the last remnants of wilderness show how vibrant ocean life was before human activity came to dominate the planet. “They act as time machines,” he said. “They are home to unparalleled levels of marine biodiversity and some of the last places on Earth you find large populations of apex predators like sharks.”

...Scientists warned in January that the oceans are suffocating, with huge dead zones quadrupling since 1950, and in February, new maps revealed half of world’s oceans are now industrially fished. “Oceans are under threat now as never before in human history,” said Sir David Attenborough at the conclusion of the BBC series Blue Planet 2 in December. 

The new research, published in the journal Current Biology, classified areas of ocean as wilderness if they were in the lowest 10% of human impacts, either from one source, such as bottom trawling, or a combination of them all.

As most are on the high seas, very few are 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 said.