top of page
  • Writer's pictureDebbie Hatch

Could the Unassuming Sea Cucumber Save Our Reefs?

Sea Cucumber

By now I hope we all know how important coral reefs are, not only to the ocean and its inhabitants but to humankind as well.  Coral is a foundation species that supports a million or more other species.  According to the National Oceanic and Atmospheric Administration, despite covering less than 1% of the ocean floor, coral reefs provide shelter and food for about 25% of all marine life!  Over half a billion people depend on reefs for food, income, and protection.


While people may disagree about the cause, there is no argument that coral cover has declined dramatically in recent decades.  Disease is a major contributor, and several coral diseases are associated with marine sediment.

In first-of-its-kind research, Mark Hay, Regents Chair in Environmental Biology in the School of Biological Sciences, Georgia Institute of Technology along with research scientist Cody Clements, have discovered a crucial missing element that seems to play a profound role in keeping coral healthy — an ocean-dwelling janitor of sorts – the unassuming sea cucumber.  In their study, when sea cucumbers were removed, “tissue death to corals more than tripled and whole colony mortality surged 15 times!” 


These scientists believe the reason might be because of the vast amounts of sand the cucumbers process.  Hay said, “we think of these sea cucumbers as little Roombas  that run around and take sand in, they digest microbes out of it.  The waste that would otherwise accumulate on the bottom of the ocean is not being left there to grow microbes.  This means less disease, the thinking goes, and healthier coral.” 


Unfortunately, sea cucumbers have been heavily harvested since the 1800s.  From 2011–2020 annual harvests increased by about 30% and reached 57,700 tons of dried sea cucumbers.  This is estimated to represent a harvest of more than 1,000,000,000 individuals per year.

With the exponential increase of human populations, the overfishing of reefs, human input of nutrients and organics, and the removal of sea cucumbers, there is now a buildup of organics and nutrients that enhance bacterial growth in the sediment. All of that is what sea cucumbers would be cleaning. 

Hay and Clements hope their findings will encourage communities to limit harvesting and begin to repopulate sea cucumber species.  Boosting sea cucumber numbers may give the reefs a fighting chance to survive. 

25 views0 comments


bottom of page