By 2050, the combined impacts of climate change and human activity on the ocean could be two to three times greater than they are today. Without urgent efforts to reduce these threats, a new study from the National Center for Ecological Analysis and Synthesis—an independent research affiliate of the University of California, Santa Barbara—warns those forces could completely transform, or even wipe out, entire seascapes.
“Huge parts of the ocean will no longer be recognizable,” said Ben Halpern, lead author of the study and the research center’s director. “There are areas that will effectively just collapse and cease to be functioning as natural systems.”
For more than 20 years, Halpern, a marine ecologist, has been charting the ways humans are reshaping coastlines and oceans. In 2008, he produced one of the first global maps to pinpoint where marine ecosystems were under the most stress at the time. Since then, he said, he has emphasized the need to look ahead and project how global warming, along with other human-driven pressures, like industrial fishing, shipping, land-based agriculture and coastal development, are likely to intensify and converge.
“Telling us how things are now is super important, but anticipating what they might be like in the future is a really powerful—and potentially more powerful—tool for informing management and conservation,” Halpern said.
His latest study does just this, providing a sweeping global forecast of which regions and marine habitats are most likely to be affected by mounting threats caused by humans.
To do this, Halpern and his team collated multiple data sets from a suite of models that predict future climate change, the movement of fish stocks and fisheries demands, as well as those that show how human populations are shifting around the world. By layering these data sets on top of one another, one of the study’s co-authors and analysts, Melanie Frazier, said they were able to identify areas most at-risk.
The results are “daunting,” Frazier said. “I hope that it motivates change, understanding that the magnitudes of our actions are going to be widely felt.”
The study shows hardly any ocean areas will go unphased. The extent of biodiversity and habitat loss will differ, however, depending on location, as will the impacts on people that rely on these environments and resources.
The United Nations estimates more than 3 billion people depend on the ocean for their livelihoods and food.
Global warming and loss of biomass due to fishing will be top contributors to the projected surge in ocean impacts, the study says. The Arctic and Antarctica will experience some of the fastest changes as a result.
The Arctic is warming at least three times faster than the rest of the world, according to Rick Thoman, a climate specialist at the International Arctic Research Center at the University of Alaska Fairbanks, who is not affiliated with the UC Santa Barbara study.
As temperatures rise, Halpern said, sea ice is melting, and consequently opening up areas for fishing that were previously inaccessible. “That will accelerate change dramatically,” he said.
Fish populations are moving due to rising temperatures. In the Bering Sea in western Alaska, Thoman said, some commercial species like Pacific cod and pollock, are gravitating towards colder waters, forcing fishing communities to reconsider where they fish and what equipment they will use. Some communities, he said, are having to invest in new vessels better suited for open water fishing as they have to increasingly travel farther offshore to make their catch.
Sea ice in Antarctica is also rapidly disappearing. In recent years, it’s reached record lows, according to a scientific paper by the Australian National University, published last month in the journal Nature. Consequently, industrial fishing vessels trawling for crustaceans called krill are gaining access to ocean areas previously blocked off by the ice and are able to stay for longer periods of time. Many scientists are concerned the growing fishery might negatively impact whales, penguins and other marine life that feed on the crustaceans, if not properly managed.
They’re calling for the main organization charged with protecting marine life in the Southern Ocean, the Commission for the Conservation of Antarctic Marine Living Resources, to revise their current krill fishery management plan so that it limits concentrated krill catches in areas used by other marine life to feed or breed.
But while the polar regions may change the fastest, coastal areas are going to bear the most severe brunt of cumulative future pressures, the study shows.
Nearshore habitats like salt marshes, seagrass meadows, mangroves and shallow coral reefs—all of which protect coastlines from storms, nurture fisheries and store carbon—are among some of the most vulnerable ecosystems.
Some of these, Halpern said, are likely to be “squeezed out” by multiple forces like sea level rise and coastal development. Shellfish reefs composed of oysters or mussels will be affected by a multitude of factors including ocean acidification—a direct result of global warming that hinders proper growth and formation of hard-shelled species—and fishing and nutrient pollution from farm runoff that can trigger harmful algal blooms, which in turn can render the shellfish toxic and not fit for eating.
None of these threats are surprising, Halpern said. Many scientists have been studying these changes to marine ecosystems for decades, he said. It is the pace at which they are expected to accelerate, based on his team’s findings, that he said is most alarming.
“These results are worrisome and sobering,” Halpern said. “It took us decades to accumulate the impact that we’ve got already today, and just in a few short years—25 years—we’re going to double, or maybe triple that.”
Altering the course of this trajectory will require concerted efforts by policy makers to reduce climate change effects and improve fisheries management in most countries, the study says.
Planning for a Sustainable and Peaceful Future
This will require significant investments from governments and other funders to support countries, especially in the tropics and subtropics, Halpern said, that lack the necessary resources needed to properly monitor and manage coastal resources.
Without the vessels and personnel dedicated to marine protection, the impacts of overfishing will continue to compound in areas where climate change effects are also taking a toll, Halpern said. It’s a “tragic” “double whammy,” he said, that many nations—especially island nations—are going to face in the future with more severity.
These compounding threats can lead to food security issues and even conflict, said Sarah Glaser, senior director of a World Wildlife Fund initiative called Ocean Futures, an online platform that maps global hotspots where climate change is most likely to exacerbate fishing disputes amongst nations or communities. The goal, she said, is to help decision makers recognize the vital role proper fisheries management plays not only in avoiding conflict, but also promoting peace.
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Donate Now“Climate change is going to cause fish populations to live in very different places in 30 years than they live now. And as those fish are reshuffled, it’s going to cause conflict either, because we’ve got competition for scarce fisheries resources, and people are fighting over fewer fish, or because fish are moving into new waters, and the past management agreements that applied no longer apply,” Glaser said. “People are going to be fighting to make sure that they’re the winners in those situations.”
Mitigating these pressures requires foresight, planning and strong governance, Glaser said.
That’s why studies like Halpern’s, together with tools like WWF’s Ocean Futures platform, are so critical, she said. They give policy makers a clearer picture of what’s at stake and where action is most urgently needed.
The ocean is resilient, Halpern said, and can recover if given the chance to bounce back.
“We’ve seen tons of evidence from a lot of countries that when you put in well enforced fisheries rules and regulations to keep the harvest at sustainable levels, the stocks rebound.”
Well managed marine protected areas that prohibit or limit fishing are a proven tool to help restore declining fish populations. A study from the University of Hawaii, published last year in Science, found these areas not only protect what’s within their boundaries; they also promote what scientists refer to as a “spillover effect.”
When fish populations recover in protected reserves they tend to move or “spill over” into adjacent waters where fishing is allowed. Across the Pacific and Indian Oceans, the University of Hawaii study showed that fishing efforts increased by 12 to 18 percent near large-scale protected areas.
On land, better management of agriculture and wastewater could make a major difference in reducing pressures on coastal habitats, Halpern said. Adjusting how fertilizers are applied or reducing their use, and investing in proper modern wastewater treatment systems would be hugely beneficial in reducing the amount of nutrient runoff that enters coastal areas. These efforts could help curb harmful algal blooms and improve water quality, protecting both marine life and human health.
But solutions can’t be piecemeal, Halpern said. Coordinated and robust efforts must be made to have real impact on reducing the cumulative future impacts on the ocean, not only by managing fisheries and land-based pollution, but by also reducing greenhouse gas emissions, expanding clean energy and supporting sustainable aquaculture, he said.
“If we can take action now and boldly, we can really make for a different future, one where the ocean is thriving and we continue to benefit from that.”
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Thank you,
Teresa Tomassoni
Oceans Correspondent
Teresa Tomassoni is an environmental journalist covering the intersections between oceans, climate change, coastal communities and wildlife for Inside Climate News. Her previous work has appeared in The Washington Post, NPR, NBC Latino and the Smithsonian American Indian Magazine. Teresa holds a master’s degree in Journalism from the Craig Newmark Graduate School of Journalism. She is also a recipient of the Stone & Holt Weeks Social Justice Reporting Fellowship. She has taught journalism for Long Island University and the School of the New York Times. She is an avid scuba diver and spends much of her free time underwater.
