The bottom trawling fishing technique is more harmful to the environment than previously thought, according to a new study. While it has long been known that this method captures fish indiscriminately, there was no available data on its carbon footprint. A recent study now shows that this method of fishing releases carbon emissions from ocean beds.
The study, published in Nature, becomes the first to give a clear estimate of the carbon emissions caused by bottom trawling. In this technique, nets are dragged along the ocean floor, scraping for fish and other ocean creatures. This damages a significant part of fish habitats and releases CO2 that had been captured in the sea bed.
The study broke the ocean into 50-square-kilometer blocks and used collected data to measure how much each square contributes to marine life in terms of fish stock, biodiversity and salinity among other aspects.
Researchers estimate that bottom trawling releases about one gigaton of carbon emissions into the atmosphere every year, meaning this method of fishing alone contributes more carbon to the atmosphere than the aviation industry at pre-pandemic levels. This practice also impedes the ability of the sea bed to continue absorbing and storing carbon. On top of the pollution, damaged habitats for fish and indiscriminate capturing of species leads to diversity degradation.
According to Enric Sala, lead author, marine biologist and National Geographic’s Explorer in Residence, the team had originally set out to find ways of discrediting this method of fishing to encourage those in the industry and governments to put an end to it. Scientists have been trying to petition governments against bottom trawling due to the effects it has on marine habitats. Bottom trawling is also one of the most expensive methods of fishing and the most destructive. Sala explained that most fishing operators that depend on bottom trawling rely on government subsidies to remain afloat. The team hopes this research will lead people to think twice about allowing bottom trawling to continue.
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