Earth’s marine wilderness has been eroded by humanity, with 13.2% now remaining across all of the oceans, a new report by Australian researchers has shown. Despite holding high genetic diversity and endemic species, wilderness areas are ignored in global environmental agreements, highlighting the need for urgent policy attention.
Highlights
- 13.2% (∼55 million km2) of the world’s ocean is classified as marine wilderness
- Little wilderness remains in coastal areas (e.g., coral reefs)
- Only 4.9% of marine wilderness is currently within marine protected areas
- Targets to retain marine wilderness are needed in global conservation strategies
‘The Location and Protection Status of Earth’s Diminishing Marine Wilderness’ report, issued in Current Biology, reveals that the 13.2% (∼55 million km2) of the world’s ocean identified as global marine wilderness is primarily located in the high seas of the southern hemisphere and at extreme latitudes.
Most wilderness within exclusive economic zones (EEZs) is found across the Arctic (6.9 million km2) or Pacific island nations (2.7 million km2;), although there is substantial wilderness in the EEZs of some other nations, such as New Zealand (25% of EEZs, 1.1 million km2), Chile (6% of EEZs, 120,000 km2), and Australia (4.3% of EEZs, ∼350,000 km2).
This is most likely due to low human populations in these areas and, in some cases, sea ice preventing human access to the ocean. However, with sea ice rapidly disappearing in the Arctic, some wilderness loss has already occurred in previously ice-covered areas, and this trend is likely to accelerate as sea ice continues to decline.
Global wilderness extent varies considerably across the ocean, with substantial wilderness in the southern high seas and very little in the northern hemisphere. For example, 26.9% (25 million km2) of the Southern Cold Water realm is defined as global marine wilderness, compared to <0.3% (13,263 km2) of the Temperate Northern Atlantic.
As such, researchers indicate that human pressures across the ocean are increasing rapidly, and nowhere in the sea is entirely free of human impacts.
We show that there is very little marine wilderness in coastal areas, with most remaining wilderness relegated to extreme latitudes or the high seas. Although there are vast differences in the amount of wilderness remaining across marine ecosystems, the level of wilderness protection is low in most ecosystems. International conservation policies should now recognize the values of wilderness and target conservation actions toward reducing threats in these areas to ensure their retention.
