Mowing Down An Eco System

30 March, 2025

The Saya de Malha Bank is so existentially crucial to the planet because it is one of the world’s biggest seagrass meadows and thus carbon sinks. Much like trees on land, seagrass absorbs carbon dioxide from the atmosphere and stores it in its roots and soil. But seagrass does it especially fast—at a rate 35 times that of tropical rainforest. What makes the situation in the Saya de Malha Bank even more urgent is that it’s being systematically decimated by a multi-national fleet of fishing ships that virtually no one tracks or polices.

Text: Ian Urbina, Maya Martin, Joe Galvin, Susan Ryan, and Austin Brush – Editors at The Outlaw Ocean Project.

More than five hundred years ago, when Portuguese sailors came across a shallow-water bank on the high seas over 700 miles east of the northern tip of Mauritius, they named it Saya de Malha, or “mesh skirt,” to describe the rolling waves of seagrass below the surface. In 2012, UNESCO considered Saya de Malha as a potential candidate to become a Marine World Heritage site, for its “Potential Outstanding Universal Value.” UNESCO described the bank as “globally unique,” concluding that it was covered in what is likely the largest seagrass meadow in the world. 

Seagrass meadows act as a nursery for sharks and other fish species, making them fundamentally important to the fishing industry, supporting the production of about a fifth of the world’s largest fisheries. (South China Sea, 2018)
Credit: Photo by WEY, licensed under CC BY-SA 4.0 

Seagrasses are frequently overlooked because they are rare, estimated to cover only a tenth of one percent of the ocean floor. “They are the forgotten ecosystem,” said Ronald Jumeau, the Seychelles Ambassador for Climate Change. Nevertheless, seagrasses are far less protected than other offshore areas. Only 26 percent of recorded seagrass meadows fall within marine protected areas, compared with 40 percent of coral reefs and 43 percent of the world’s mangroves. 

The Saya de Malha is one of the world’s largest carbon sinks. Much like trees on land, seagrass absorbs carbon dioxide, the primary culprit behind human-caused climate change, and stores it in its roots and soil. (2022)
Credit: Monaco Explorations

Often described as the lungs of the ocean, seagrasses capture about a fifth of all its carbon and they are home to vast biodiversity. Thousands of species, including in the Saya de Malha Bank, many as yet unknown to science, depend on seagrasses for their survival. But the planet has lost roughly a third of them since the late nineteenth century and we lose 7 percent more each year – roughly equivalent to losing a football pitch of seagrass every 30 minutes. 

Seagrass meadows like the Saya de Malha bank absorb about a fifth of all oceanic carbon. They also clean polluted water. Acting as a dense net, they trap microplastics and lock them away in the sediment.
Credit: Licensetoswill

Seagrass also cleans polluted water and protects coastlines from erosion, according to a 2021 report by the University of California, Davis. At a time when at least eight million tons of plastic end up in the ocean every year, seagrass traps microplastics by acting as a dense net, catching debris and locking it into the sediment, found a 2021 study in Nature. At a time when ocean acidification threatens the survival of the world’s coral reefs and the thousands of fish species that inhabit them, seagrasses reduce acidity by absorbing carbon through photosynthesis, and provide shelters, nurseries, and feeding grounds for thousands of species, including endangered animals such as dugongs, sharks, and seahorses. 

Scientists expect there are hundreds, if not thousands, of species previously unknown to science that rely on seagrass environments like the Saya de Malha bank. (2022) Credit: Monaco Explorations

But the Saya de Malha is under threat. More than 200 distant-water vessels – most of them from Sri Lanka and Taiwan – have parked in the deeper waters along the edge of the bank over the past few years to catch tuna, lizardfish, scad and forage fish that is turned into protein-rich fishmeal, a type of animal feed. Ocean conservationists say that efforts to conserve the bank’s sea grass are not moving fast enough to make a difference. “It’s like walking north on a southbound train,” Heidi Weiskel, Acting Head of Global Ocean Team for IUCN.  

On May 23, 2022, the United Nations General Assembly adopted a resolution to declare March 1 as World Seagrass Day. The resolution was sponsored by Sri Lanka. Speaking at the assembly, the Permanent Representative of Sri Lanka to the UN, Ambassador Mohan Pieris, said seagrasses were “one of the most valuable marine ecosystems on earth,” highlighting, among other things, their outsized contribution to carbon sequestration. But recognition is one thing; action is another. As the ambassador gave his speech in New York, dozens of ships from his country’s fishing fleet were 9,000 miles away, busily scraping the biggest of those very ecosystems he was calling on the world to protect.

Reportage: Ian Urbina, Maya Martin, Joe Galvin, Susan Ryan, and Austin Brush - Editors at The Outlaw Ocean Project.

Related articles

A colossal squid has been captured on camera for the first time in the depths of the ocean by an international research team....
Text: TT/Nyhetsbyrån
Photo: ROV SuBastian/AP/TT
In 2015, an infamously-scofflaw fleet of more than 70 bottom trawlers from Thailand fished in the Saya De Malha Bank, a submerged plateau the size...
Text: Ian Urbina, Maya Martin, Joe Galvin, Susan Ryan, and Austin Brush - Editors at The Outlaw Ocean Project.
In February, one of the salmon pens sank off the small town of Storvik in Norway and 27 000 farmed salmon escaped. The Norwegian Coast...
Text: Lena Scherman
Scroll to Top