Study shows human impacts on oceans nearly doubled in recent decade, could double again without adequate action

Doubling down
Credit: UCSB

Over the recent decade, total human impacts to the world's oceans have, on average, nearly doubled and could double again in the next decade without adequate action. That's according to a new study by researchers from the National Center for Ecological Analysis and Synthesis (NCEAS) at UC Santa Barbara.

Published in the journal Scientific Reports, the study assessed for the first time where the combined impacts that humans are having on oceans—from nutrient to overfishing—are changing and how quickly. In nearly 60% of the , the cumulative impacts are increasing significantly and, in many places, at a pace that appears to be accelerating.

"That creates even more urgency to solve these problems," said lead author Ben Halpern, director of NCEAS and a professor at UC Santa Barbara's Bren School of Environmental Science & Management.

Climate change is a key factor driving the increase across the world, as seas warm, acidify and rise. On top of that, commercial fishing, runoff from land-based pollution and shipping are intensifying progressively each year in many areas of the ocean.

"It's a multifactor problem that we need to solve. We can't just fix one thing if we want to slow and eventually stop the rate of increase in cumulative impacts," said Halpern.

The study also projected the impacts one decade into the future, based on the rate of change in the recent past, finding that they could double again if the pace of change continues unchecked.

The assessment provides a holistic perspective of where and how much human activities shape ocean change—for better or worse—which is essential to policy and planning.

"If you don't pay attention to the big picture, you miss the actual story," said Halpern. "The bigger picture is critical if you want to make smart management decisions—where are you going to get your biggest bang for your buck."

Regions of particular concern include Australia, Western Africa, the Eastern Caribbean islands and the Middle East, among others. Coastal habitats such as mangroves, coral reefs and seagrasses are among the hardest-hit ecosystems.

There is an upside to the story, however. The authors did find "" around every continent, areas where impacts have declined, such as the seas of South Korea, Japan, the United Kingdom and Denmark, all of which have seen significant decreases in and pollution.

These declines suggest that policies and other actions to improve ocean conditions are making a difference—although, the analysis does not attribute specific actions to those declines.

"We can improve things. The solutions are known and within our grasp. We just need the social and political will to take action," said Halpern.

To assess the pace of change, the authors leveraged two previous and similar assessments conducted by several of the same team members and others in 2008 and 2013, which provided first glimpses into the full, cumulative extent of humanity's impacts on oceans.

"Previously, we had a good measure of the magnitude of , but not a clear picture of how they are changing," said co-author Melanie Frazier, a data scientist at NCEAS.

Frazier was surprised to see in the data how dramatically ocean temperatures have increased in a relatively short period of time.

"You don't need fancy statistics to see how rapidly ocean temperature is changing and understand the magnitude of the problem," said Frazier. "I think this study, along with many others, highlights the importance of a concerted global effort to control ."

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More information: Benjamin S. Halpern et al, Recent pace of change in human impact on the world's ocean, Scientific Reports (2019). DOI: 10.1038/s41598-019-47201-9

Benjamin S. Halpern et al. A Global Map of Human Impact on Marine Ecosystems, Science (2008). DOI: 10.1126/science.1149345

Benjamin S. Halpern et al. Spatial and temporal changes in cumulative human impacts on the world's ocean, Nature Communications (2015). DOI: 10.1038/ncomms8615

Citation: Study shows human impacts on oceans nearly doubled in recent decade, could double again without adequate action (2019, August 13) retrieved 23 August 2019 from
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Aug 14, 2019
The ocean can only absorb this much Man made pollution and Co2, before it goes curtains to all living beings on this planet ! ! ! !

Aug 14, 2019
Relax, some thing else will cause your death, no personal danger involved.
Besides, only living beings that cannot adapt will die, which may be quite a few.
But the niches left by their death will be filled by the survivors adapting the newly available food.
There have been several climate induced extinctions and this is the pattern. The only new part is mankind is aware, in the past it was a surprise every time.

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