Bottom trawling releases as much carbon as air transport, finds landmark study | Marine life
Fishing boats trawling the ocean floor release as much carbon dioxide as the entire aviation industry, according to groundbreaking study.
Bottom trawling, a widespread practice in which heavy nets are dragged along the seabed, pumps up 1 gigatonne of carbon each year, says the study written by 26 marine biologists, climate experts and economists and published in Nature on Wednesday.
Carbon is released from seabed sediments into the water and can increase ocean acidification, as well as adversely affect productivity and biodiversity, according to the study. Marine sediments constitute the largest carbon storage reservoir in the world.
The report – Protecting the Global Ocean for Biodiversity, Food and Climate – is the first study to show the climate impacts of trawling on a global scale. It also provides a plan defining areas of the ocean that should be protected to protect marine life, boost seafood production, and reduce climate emissions.
Only 7% of the ocean is in some form of protection. Scientists argue that by identifying strategic areas of stewardship – for example, regions with large-scale industrial fisheries and large economic exclusion zones or marine territories – nations could reap “significant benefits” to the world. climate, food and biodiversity. Protecting “strategic” ocean areas could produce 8 million tonnes of seafood, they say.
“Ocean life is in decline around the world due to overfishing, habitat destruction and climate change,” said Dr. Enric Sala, Explorer-in-Residence at the National Geographic Society and senior author of the ‘article. “In this study, we pioneered a new way to identify places that, if strongly protected, will boost food production and protect marine life, while reducing carbon emissions.
“It is clear that humanity and the economy will benefit from a healthier ocean. And we can realize these benefits quickly if countries work together to protect at least 30% of the ocean by 2030. ”
Scientists have identified marine areas where species and ecosystems are most threatened by human activities. They developed an algorithm to identify regions where safeguarding would provide the greatest benefits through three objectives: biodiversity protection, seafood production and climate mitigation. They then mapped them out to create a practical “blueprint” that governments can use, depending on their priorities.
The 10 countries emitting the most carbon from bottom trawling, and therefore the most to gain, were China, Russia, Italy, the United Kingdom, Denmark, France, the Netherlands, Norway, Croatia and Spain.
Analysis shows that the world must protect at least 30% of the ocean in order to provide multiple benefits. Scientists say their results confirm the ambition to protect at least 30% of the ocean by 2030, which is part of the goal adopted by a coalition of 50 countries this year to slow the destruction of the natural world.
Zac Goldsmith, the UK’s Minister for the Pacific and the Environment, described the document as “an important contribution to science on ocean protection and stresses the need for countries to work together to protect at least 30% of the world ocean by 2030 ”.
He said the UK was playing a leading role in a global ocean alliance supporting this goal and pledged: “We will do all we can to achieve it at the United Nations Biodiversity Conference in China.”
“There is no better way to save marine life and achieve these other benefits. The solution depends on what society – or a particular country – cares about, and our study provides a new way to integrate these preferences and find effective conservation strategies, ”said Dr Juan S Mayorga, co-author of the report and marine data specialist. the Environmental Market Solutions Lab at the University of California at Santa Barbara; and Pristine Seas at the National Geographic Society.
The study calculates that eliminating 90% of the current risk of carbon disturbance from bottom trawling would only require protecting about 4% of the ocean, mostly in national waters.
Dr David Mouillot, co-author of the report and professor at the University of Montpellier in France, said: “A notable priority for conservation is Antarctica, which currently has little protection, but is expected to host many vulnerable species. in the near future due to climate change. “
The study estimated emissions between 0.6 and 1.5 gigatonnes of carbon dioxide per year, or an average of 1 gigatonne per year. Aviation carbon dioxide emissions in 2019 were 918 million tonnes.
The UN biodiversity conference, Cop15, due to be held in Kunming, China this year, is expected to result in a global accord for nature, building on targets already set by some countries to protect at less 30% of the ocean by 2030..