Trawling ocean floor for fishing can release carbon equal to air travel: Study

The practice of bottom trawling, according to the study, pumps out carbon amounting to about 1 gigaton every year. Marine sediments happen to be the largest reservoir of carbon in the world

March 29, 2021 by Liberation News
A trawler near the Saint Martin Island. Photo: Kirtinasha (Nazrul), CC BY-SA 3.0 , via Wikimedia Commons

It is increasingly clear that human activity is causing tremendous pressure on the environment, ecosystem and biodiversity. New aspects of destruction of the environment by human activities are emerging daily causing a great deal of concern.

Now, a study published in Nature on March 17 says that fishing can also contribute to the release of huge amount of carbon and make the oceans more acidic. It found that fishing boats that trawl the ocean floor can release carbon dioxide as much as the entire aviation industry.

In many parts of the world, large scale fishing practices include bottom trawling, where heavy fishing nets are dragged upon the seabed. This practice, according to the study, pumps out carbon amounting to about 1 gigaton every year. The study involved 26 marine biologists, climate experts and economists.

In this practice of fishing, carbon is released from the seabed sediment into the water above. The released carbon can increase the acidification of the oceans, which in turn adversely affect marine biodiversity and productivity. Marine sediments happen to be the largest reservoir of carbon in the world.

The study –“protecting the global ocean for biodiversity, food and climate” – is the first one to estimate what impact can seabed trawling have on the global climate. The study also points out which regions are to be protected as a first line of defense of marine life and also boost seafood productivity as well as to reduce adverse climate impact.

According to the study, only about 7% of the ocean is under protection. The scientists involved in the study propose that there is an urgent need to identify strategic areas of protection  for example, identifying the regions where large scale commercial fishing takes place, major economic exclusion zones or some marine territories etc. The scientists urge nations to set up concerted efforts to mitigating the danger in future. They say that strategic protection of oceans can produce 8 million tonnes of seafood.

Commenting on the study, Dr. Enric Sala, explorer-in-residence at the National Geographic Society and lead author of the paper, was quoted to have said—“Ocean life has been declining worldwide because of overfishing, habitat destruction and climate change. 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.”

“It’s clear that humanity and the economy will benefit from a healthier ocean. And we can realize those benefits quickly if countries work together to protect at least 30% of the ocean by 2030”—the author further added.

The scientists have developed an algorithm to identify regions where safeguarding can offer benefits in biodiversity protection, climate mitigation and seafood protection. They also produced a blueprint about how governments of different countries can implement the safeguarding strategies effectively.

The countries that account for most of the seabed trawling and hence, most of the carbon emissions are China, Russia, Italy, UK, Denmark, France, Netherlands, Norway, Croatia and Spain.

The study projects that 30% of the oceans must be protected with immediate effect. They also said that the analysis is important for the project wherein 50 countries have agreed to protect 30% of Earth’s land and oceans till 2030.