Almost all world’s oceans damaged by human impact, study finds

The remaining wilderness areas, mostly in the remote Pacific and at the poles, need urgent protection from fishing and pollution, scientists say
Damian Carrington The Guardian 26 Jul 18;

Just 13% of the world’s oceans remain untouched by the damaging impacts of humanity, the first systematic analysis has revealed. Outside the remotest areas of the Pacific and the poles, virtually no ocean is left harbouring naturally high levels of marine wildlife.

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.”

Much of the wilderness is in the high seas, beyond the protected areas that nations can create. The scientists said a high seas conservation treaty is urgently needed, with negotiations beginning in September under the UN Law of the Sea convention. They also said the $4bn a year in government subsidies spent on high seas fishing must be cut. “Most fishing on the high seas would actually be unprofitable if it weren’t for big subsidies,” Jones said.

The new work joins recent studies in highlighting the threat to oceans. 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.

Climate change is causing growing damage and Jones said Arctic wilderness areas protected by ice cover in the 1970s had now been lost after the ice melted and fishing boats were able to access them. It is increasingly a global problem, he said: “In future, as climate change gets worse, I think you can definitely say pretty much everywhere in the ocean is going to come under increasing level of threat.”

There are some bright spots, such as the remote corals in the British Indian Ocean Territory around Diego Garcia, from which islanders were controversially removed in the 1960s. In the Antarctic, major fishing companies now back the creation of the world’s biggest marine sanctuary.

The new study aimed to include the maximum area of likely wilderness, said Ward Appeltans, at the Intergovernmental Oceanographic Commission run by Unesco: “So the claim that only 13% of ocean wilderness remains is all the more striking.” He said the research focused on the ocean floor, and did not include impacts on the water column above it, and backed calls for a global ocean conservation treaty.

Jones said: “Beyond just valuing nature for nature’s sake, having these large intact seascapes that function in a way that they always have done is really important for the Earth. They maintain the ecological processes that are how the climate and Earth system function – [without them] you can start seeing big knock-on effects with drastic and unforeseen consequences.”

Ocean wilderness 'disappearing' globally
Mary Halton BBC 27 Jul 18;

Scientists have mapped marine "wilderness" areas around the world for the first time.

These are regions minimally impacted by human activities such as fishing, pollution and shipping.

The team, led by researchers in Australia, found that just 13.2% of the world's oceans could be classed as wilderness - most in international waters, away from human populations.

Very few coastal areas met the criteria, including coral reefs.

Reefs are some of the most biodiverse habitats in the ocean, as they are home to a great number of different plant and animal species. They are thought to be vital areas for marine life.

What makes a wilderness?

"It's a place where the environment and ecosystem is acting in basically an undisturbed way that's free from human activity," explained lead author Kendall Jones.

"Studies have shown that places free from intense levels of human activity have really high levels of biodiversity and high genetic diversity [but] we didn't have an idea of where across the globe these intact places could still be found," the Wildlife Conservation Society researcher told BBC News.

Jones and other scientists set out to analyse the impact of 15 different human activities or "stressors" on global ocean environments, in order to map these regions. Areas that experienced the least impact - the bottom 10% - were classed as wilderness.

Data from satellites, ship tracking and pollution reports from individual countries were analysed.

Dr Rachel Hale from the University of Southampton, observed that "marine wildernesses are largely overlooked in terms of conservation priorities when compared to terrestrial ones, and it is extremely interesting to see where in the world these lie and what habitats they cover.

"They could be important corridors connecting habitats and species populations," added Dr Hale, who was not involved in the study.

How much is left?
The team found that most of the areas they defined as wilderness fell within the Arctic, Antarctic and around Pacific Island nations, or in the open ocean, where human activity is more limited.

Despite their conservation status, marine protected areas (MPAs) appear to host just 4.9% of global marine wilderness.

Mr Jones also noted that wilderness areas exposed by the decline of sea ice in the Arctic are now potentially vulnerable to anthropogenic impacts.

What can be done?

Although Mr Jones points out that fishing is one of the most significant direct impacts that humans can have on ocean ecosystems, many of the problems being caused originate on land.

Runoff of nutrients from farming fertilisers, chemicals from poorly controlled industrial production, and the influx of plastic pollution from rivers are all disrupting ocean life.

"Plastic pollution is one of the big things that we want to work out a way to get data on," he told the BBC.

"It's so widespread and so hard to manage that we really want to get a good idea of where it is and where is most affected."

The UN are currently considering a legally binding addition to the Convention on the Law of the Sea, which would mandate conservation and sustainable use of international waters - currently not protected.

The first of four conferences to determine the details will take place in September 2018.

Mr Jones welcomes this: "It's good that the international community is starting to recognise the need for improved management of international waters."

However Dr Hale points out that the issues could prove more complex, with many problems traversing legal and international boundaries.

"Formal protection of these wilderness areas would not be able to protect them from some stressors such as climate change and invasive species," she told the BBC.

"We should prioritise conservation actions in at-risk and/or biologically important areas, and identifying these areas within the identified marine wilderness areas would be a positive next step."

The findings are published in Current Biology.

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