OVERHARVESTED SEA CUCUMBERS PLAY CRUCIAL ROLE IN PROTECTING CORAL

Overharvested sea cucumbers play crucial role in protecting coral. In a first-of-its-kind study, the researchers discovered that sea cucumbers protect coral from disease.
Corals are foundational for ocean life. Known as the rainforests of the sea, they create habitats for 25% of all marine organisms, despite only covering less than 1% of the ocean’s area.
Coral patches the width and height of basketball arenas used to be common throughout the world’s oceans. But due to numerous human-generated stresses and coral disease, which is known to be associated with ocean sediments, most of the world’s coral is gone.
“It’s like if all the pine trees in Georgia disappeared over a period of 30 to 40 years,” said Mark Hay, Regents’ Chair and the Harry and Anna Teasley Chair in Environmental Biology in the School of Biological Sciences at the Georgia Institute of Technology. “Just imagine how that affects biodiversity and ecosystems of the ocean.”
Their study, undertaken in remote tropical islands in the Pacific, investigated the role that sea cucumbers play in coral health. The small, unassuming, sediment-eating organisms function like autonomous vacuum cleaners of the ocean floor. But, because they have been overharvested for decades for food and cannot reproduce effectively when in low densities, they are now rare and slow to recover following harvests. They have been gone so long that it wasn’t known exactly how important they are — until now.
“We knew that removing big predators has cascading effects that commonly change how ecosystems are organised and how they function,” said Hay. “What we didn’t know is what would happen following removal of detritivores — or as we like to call them, the janitors of the system.”
The team’s research was published in the journal Nature Communications.