World’s scientific community proposes what’s needed to protect the planet’s oceans, as the United Nations prepares a treaty. Scientists say that at least 30% of the global ocean, distributed evenly between ocean ecosystems, should be cordoned off to avoid a mass extinction of marine life. On paper, almost 7% of the ocean is now protected: in the past 3 years, 13 of the world’s largest Marine Protected Areas (MPAs), all more than 100,000 square kilometers in area, have been created in coastal waters — largely impelled by a UN goal to protect 10% of the ocean by 2020.
In practice, however, reports the journal Nature, these protections are often less than adequate. To be effective, MPAs need key traits: they must be ‘no-take’, or completely off-limits to commercial activity; have an area of at least 100 square kilometers; be permanent and physically isolated from their unprotected surroundings by deep water or sand; and have well-enforced protections. An analysis of 87 MPAs found that those with only one or two of these traits were ecologically indistinguishable from fished sites.
Many coastal MPAs, reports Nature allow for oil and gas exploration, shipping and fishing. Only 2% of the ocean is no-take, and these MPAs are mostly in deep tropical waters of little interest to industry, so do little to reduce overall exploitation of the ocean. As for the high seas, just 0.5% is off-limits to commercial exploitation. (Much of this is due to the largest international MPA, in the Ross Sea off Antarctica, which was created by a regional 25-nation council).
“As is often the case closer to shore, there’s a serious risk that high-seas MPAs will be sited in areas of low commercial interest,” says Elizabeth De Santo, an environmental-management specialist at Franklin and Marshall College in Lancaster, Pennsylvania. How scientific advice on MPAs will feed into the UN treaty is yet to be decided. But debates about coastal MPAs suggest that scientists’ fears of being ignored are well-founded. In the planned Laurentian Channel MPA off the coast of Canada, for example, it’s possible to drill for oil and gas in almost 90% of the reserve, against scientific advice.
There’s no shortage of ideas for marine protected areas (MPAs) on the high seas. UN organizations have listed dozens of vulnerable ecosystems, as have regional fisheries bodies and non-governmental organizations. This map highlights ten sites that showcase the diversity of ecosystems on the high seas and the range of threats they face.
1. Dead zones. Pollutants from agricultural runoff can cause plankton blooms in the Bay of Bengal, a shallow, warm part of the Indian Ocean. The blooms suck up oxygen, leaving dead zones that total at least 60,000 square kilometres. Further runoff or a change in monsoons could cause huge-scale oxygen depletion, radically changing an ecosystem that provides jobs and food security to more than 100 million people.
2. Coral crunch. Between the Hawaiian and Aleutian islands, a chain of deep-sea volcanoes provides nutrient-rich waters for migrating albatrosses, whales and tuna. Corals and fish have been hit hard by trawling and are struggling to recover.
3. Shark cafe. Hundreds of great white sharks (Carcharodon carcharias) forage and breed here, in a region at risk from fishing and shipping. These sharks are a genetically distinct population and of higher concern even than other great whites; the species as a whole could number as few as 3,500 in the wild.
4. Sea-bed mining. Scattered on and below the sea bed are trillions of nodules — potato-sized, rock-like deposits rich in many valuable minerals. But the region also hosts rare marine species, including a species of ghost octopus that was discovered in 2016. The International Seabed Authority has issued 16 contracts to explore the area for minerals. Scientists say at least one-third of the zone should be off-limits to mining, with controls in place where it is permitted.
5. First new MPA? East Antarctica, a relatively pristine ecosystem that is home to Adélie (Pygoscelis adeliae) and emperor (Apterodytes forsteri) penguins, the seas here are rich in cold-water corals. This region is also the origin of Antarctic bottom water, a cold, dense and oxygenated water mass that drives the circulation of the global ocean. All this amkes it a clear choice for a high-seas MPA. But China and Russia have interests in fishing krill here; in 2017, it was rejected as an MPA for the sixth consecutive year by the Commission for the Conservation of Antarctic Marine Living Resources.
6. Dynamic dome. Strong winds drive currents that force cold, nutrient-rich waters to well up from the deep to just below the surface. Iconic ocean species come here, including mahi-mahi, billfish, sharks, squid, cetaceans and endangered sea turtles. But this ‘thermic dome’ shifts its position, and only seasonally occurs on the high seas, so it is challenging to protect.
7. Marine rainforest. The Sargasso region is one of 37 EBSAs, or ‘Ecologically or Biologically Significant Marine Areas’ on the high seas. The UN designation identifies the regions as important to healthy ocean function but does not protect them.
8. Hydrothermal field. Discovered in 2000, the ‘Lost City’ system could give clues to the necessary precursors for life on Earth. At a depth of 800 metres, this acidic, hot ecosystem extends for about 400 metres along the top of an underwater mountain known as the Atlantis Massif. The United Nations Educational, Scientific and Cultural Organization has proposed a 20-kilometre buffer zone.
9. Ineffective sanctuary. This refuge, regarded as the first ever high-seas MPA, was created in 1999 to protect the many cetacean species that visit its waters. But the sanctuary lacks management and has had little effect. If expanded and implemented properly, it could provide refuge for bluefin tuna, sharks and swordfish.
10. Oil and gas. This 1,800-kilometre mountain chain hosts active volcanoes, hydrothermal vents and unique creatures such as eyeless shrimp (Rimicaris exoculata), which could be vulnerable to shipping and oil and gas exploration as the Arctic warms.
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