Ground-breaking global study is the first to map ocean areas that, if strongly protected, would help solve climate, food and biodiversity crises.
For the first time ever, a study published in peer-reviewed scientific journal Nature offers a combined solution to several of humanity’s most pressing challenges – and the answer all lies in protecting our oceans. The study is the most comprehensive assessment to date that shows how strict ocean protection can contribute to a more abundant supply of healthy seafood and provide a cheap, natural solution to address climate change, as well as protecting embattled species and habitats.
An international team of 26 authors made up of leading marine biologists, climate experts, and economists, identified specific areas that, if protected, would safeguard over 80% of the habitats for endangered marine species, and increase fishing catches by more than eight million metric tons. The majority of these areas are contained within the 200-mile Exclusive Economic Zones of coastal nations, with the remaining located in the high seas, or waters governed by international laws. These areas include the Mid-Atlantic Ridge, the Mascarene Plateau in the Indian Ocean, the Nazca Ridge off the west coast of South America and the Southwest Indian Ridge, between Africa and Antarctica.
“Ocean life has been declining worldwide because of overfishing, habitat destruction and climate change. Yet only 7% of the ocean is currently under some kind of protection,” said Dr. Enric Sala, lead author of the study, Protecting the global ocean for biodiversity, food and climate and marine biologist who directs National Geographic’s Pristine Seas project.
“In this study, we’ve pioneered a new way to identify the places that, if strongly protected, will boost food production and safeguard marine life, all while reducing carbon emissions,” Dr. Sala said. “It’s clear that humanity and the economy will benefit from a healthier ocean. And we can realise those benefits quickly if countries work together to protect at least 30% of the ocean by 2030.”
To identify the priority areas, the authors analysed the world’s unprotected ocean waters based on the degree to which they are threatened by human activities that can be reduced by marine protected areas such as overfishing and habitat destruction. They then developed an algorithm to identify those areas where protections would deliver the greatest benefits across the three complementary goals of biodiversity protection, seafood production and climate mitigation. They mapped these locations to create a practical “blueprint” that governments can use as they implement their commitments to protect nature.
The study offers a first-in-kind framework for countries to decide which areas to protect depending on their national priorities. However, the analysis shows that 30% is the minimum amount of ocean that the world must protect in order to provide multiple benefits to humanity.
“There is no single best solution to save marine life and obtain these other benefits. The solution depends on what a given country cares about, and our study provides a new way to integrate these preferences and find effective conservation strategies,” said Dr. Juan S. Mayorga, a report co-author and a marine data scientist with the Environmental Market Solutions Lab at UC Santa Barbara and Pristine Seas at National Geographic Society.
The study comes ahead of the 15th Conference of the Parties to the United Nations Convention on Biological Diversity, which is expected to take place in Kunming, China this year. The meeting will bring together representatives of 190 countries to finalise an agreement to end the world’s biodiversity crisis. The goal of protecting 30% of the planet’s land and ocean by 2030 (the “30×30” target) is expected to be a pillar of the treaty.
The study follows commitments by the United States, the United Kingdom, Canada, the European Commission and others to achieve this target on national and global scales.
Zac Goldsmith is the British Minister for Pacific and the Environment. He believes the study reveals the urgent “need for countries to work together to protect at least 30% of the global ocean by 2030.”
Hanging Up the Fishing Nets
The study finds that smartly placed MPAs that ban fishing would actually boost the production of fish – at a time when supplies of wild-caught fish are dwindling and demand is rising. In doing so, the study refutes a long-held view that ocean protection harms fisheries and opens up new opportunities to revive the industry just as it is suffering from a recession due to overfishing and the impacts of global warming.
“Some argue that closing areas to fishing hurts fishing interests. But the worst enemy of successful fisheries is overfishing, not protected areas,” Dr. Sala said.
“It’s simple: When overfishing and other damaging activities cease, marine life bounces back,” said Dr. Reniel Cabral, a report co-author and assistant researcher with the Bren School of Environmental Science & Management and Marine Science Institute at UC Santa Barbara.
After protections are put in place, the diversity and abundance of marine life increases over time, with measurable recovery occurring in as little as three years. Target species and large predators come back, and entire ecosystems are restored within MPAs.
“After protections are put in place, the diversity and abundance of marine life increases over time, with measurable recovery occurring in as little as three years.” – Dr. Reniel Cabral
Trawling for Carbon
The study is the first to calculate the climate impacts of bottom trawling, a damaging fishing method used worldwide that drags heavy nets across the ocean floor. It reveals that the amount of carbon dioxide released into the ocean from this practice is larger than most countries’ annual carbon emissions, and similar to annual carbon dioxide emissions from global aviation.
“The ocean floor is the world’s largest carbon storehouse. If we’re to succeed in stopping global warming, we must leave the carbon-rich seabed undisturbed. Yet every day, we are trawling the seafloor, depleting its biodiversity and mobilising millennia-old carbon and thus exacerbating climate change. Our findings about the climate impacts of bottom trawling will make the activities on the ocean’s seabed hard to ignore in climate plans going forward,” said Dr. Trisha Atwood of Utah State University, a co-author of the paper.
The study finds that countries with the highest potential to contribute to climate change mitigation via protection of carbon stocks are those with large national waters and large industrial bottom trawl fisheries. It calculates that eliminating 90% of the present risk of carbon disturbance due to bottom trawling would require protecting only about 4% of the ocean, mostly within national waters.
Closing a Gap
The study’s range of findings helps to close a gap in our knowledge about the impacts of ocean conservation, which to date had been understudied relative to land-based conservation.
“The ocean covers 70% of the earth – yet, until now, its importance for solving the challenges of our time has been overlooked,” said Dr. Boris Worm, a study co-author and Killam Research Professor at Dalhousie University in Halifax, Nova Scotia.
“Smart ocean protection will help to provide cheap natural climate solutions, make seafood more abundant and safeguard imperilled marine species – all at the same tine. If we want to solve the three most pressing challenges of our century – biodiversity loss, climate change and food shortages – we must protect our oceans.”