The Race To Breathe New Life Into 'The Lungs Of The World'

From their leaves down to their roots, seagrasses work as 'ecosystem engineers', yet they have become one of the least protected species of coastal life

-  Allyson Chiu

From the deck of a small blue-and-white boat, Bashiru Bangura leaned forward and peered into the ocean, his gaze trained on a large dark patch just beneath the jade-green waves. "It's here! It's here! It's here!" crowed a local fisherman, who led Bangura to this spot roughly 60 miles off the coast of Freetown. "It looks black!"

Bangura, who works for Sierra Leone's Environment Protection Agency (EPA), tempered his excitement. After two unsuccessful attempts to find seagrass in this group of islands, he questioned whether the shadowy blotches were meadows of the critical underwater greenery he and other researchers have spent the past several years trying to locate along the coast of west Africa.

It was only once he was standing in the waist-high water, marvelling at the tuft of scraggly hair-like strands he'd uprooted to collect as a sample, that he allowed himself to smile. The wet, reedy plants Bangura holds in his hands are unmistakably seagrass, and the green blades stretch past the plastic 12in ruler he's been using to measure specimens. His grin grew even wider. The dense grass swaying in the current appeared to be healthy, and the water teems with schools of small, silvery fish, making it the best site researchers have documented in these islands since the existence of seagrass was first confirmed in Sierra Leone in 2019.

"Discovering that site, it was a great moment for us," Bangura says. Seagrasses - which range from stubby sprout-like vegetation to elongated plants with flat, ribbon-like leaves - are one of the world's most productive underwater ecosystems. The meadows are vital habitats for a variety of aquatic wildlife. Sometimes described as "the lungs of the sea", the grasses produce large amounts of oxygen essential for fish in shallow coastal waters.