Finding out that industrial fishing fleets operating in near-total obscurity are methodically scraping the ocean floor—a location that most of us will never see, photograph, or visit—is almost surreal. Not in a single place. Everywhere. Weighted nets sinking hundreds of meters through chilly, dark water drag about the area of a football field clean every second of every day. Coral formations that existed before the Roman Empire are being reduced to gravel in a matter of minutes somewhere down there.
Deepwater bottom trawling has been referred to by marine scientists as the “clear-cutting of the ocean,” a comparison that seems almost generous when you consider the workings of the technique. When a forest is destroyed on land, the devastation is at least apparent. It is captured by satellite imagery. Journalists overlook it. Politicians are questioned about it. Part of the reason it has been permitted to go on for so long is that what occurs on a seamount two kilometers below the surface is by default invisible.
Seamounts are not desolate geological formations. They are underwater mountains that rise sharply from the ocean floor. Sharks, whales, turtles, and hundreds of fish species use them as nurseries and feeding grounds, making them some of the planet’s most biodiverse habitats. Cold-water corals and sponges, some of which are thought to be 5,000 years old, flourish in slow, quiet abundance due to the water movement around their flanks. These characteristics of the ocean are not coincidental. They support the ocean’s ability to absorb and store carbon as well as marine biodiversity. One seamount is not the only one that is harmed. It’s possible that the ripple effects extend far beyond what science is currently able to detect.
Ocean, a recent documentary by Sir David Attenborough, provided the general public with their first comprehensive understanding of the practical effects of trawling. According to reports, the footage, which showed ancient coral colonies exploding into debris clouds and heavy, metal-doored nets grinding across the seafloor off the coast of Turkey, left viewers stunned in a way that years of scientific papers had never quite managed. That’s for a reason. It’s one thing to read that carbon dioxide emissions from bottom trawling are “equivalent to the entire aviation industry annually”. It is quite another to witness a reef that has been built over centuries vanish in a single net pass.
This story’s carbon dimension is still poorly understood, and it ought to be. According to research, up to 370 million metric tonnes of carbon dioxide are released annually when marine sediments are disturbed; the majority of this carbon dioxide has been stored in the seafloor for centuries. Within ten years, a sizable amount—between 55 and 60 percent—enters the atmosphere. Ocean acidification is made worse by the remainder. In other words, bottom trawling is more than just a biodiversity issue. Wearing a fishing license is a climate issue.
The scientific community has been sounding these alarms for more than 20 years, which is frustrating. A letter urging the United Nations to protect seamounts and deep-sea ecosystems from industrial fishing was signed by over a thousand scientists in 2004. In response, the UN General Assembly passed resolutions. Commitments were made by regional fisheries organizations. A significant portion of the Mediterranean’s seamount ecosystems were protected when bottom trawling below 1,000 meters was outlawed in 2005. By 2030, the EU has mandated that trawling in marine protected areas cease. However, enforcement is still lax almost everywhere, and a few nations continue to permit the practice on high seas ecosystems in direct opposition to scientific recommendations. Bottom trawling is currently the biggest threat to seamount ecosystems, according to the second UN World Ocean Assessment, which was released in 2021. Nevertheless, the practice persists.
It’s difficult to ignore a pattern when observing this situation develop over several decades: rigorous science, political recognition, and insufficient follow-through. Nearly 64% of the world’s bottom trawling catch comes from ten nations, including China, Vietnam, and Indonesia. To get around licensing restrictions in West Africa, foreign trawlers have made ingenious agreements with local companies. Eighty-six percent of Natura 2000 marine protected areas in European waters are still impacted by destructive fishing. There is still a huge discrepancy between what governments have agreed to do and what is actually enforced.
At the very least, there is increasing pressure to close it. A new letter urging UN members to fulfill their commitments is being circulated by scientists. The international community is given a specific deadline and a framework for action by the 30×30 target, which calls for protecting 30% of the ocean by 2030. It is genuinely unclear whether this momentum will result in actual seamount protection or just another round of resolutions and rhetorical concern. It might be the only question that counts for the coral colonies that are still standing atop those underwater mountains.
