Sea Cucumber Excrement Could Save Coral Reefs

Sea Cucumber Excrement Could Save Coral Reefs

Oceans around the world have been acting like carbon sponges for billions of years.

Oceans suck in huge amount of carbon dioxide and thus maintaining the level of carbon dioxide in our atmosphere. They act link a sink or deposit box for carbon emissions. But the continuous rise of carbon dioxide level due to anthropogenic activities causes the oceans to become acidic. Yes-even with 4 feet of snow in Buffalo in recent weeks, HUMAN KIND IS ALTERING THE ENVIRONMENT.  

Low water pH is detrimental to coral reefs and aquatic lives, annihilating delicate reefs and fish eggs. This acidic water also effects the calcification of corals, their growth and ability to buffer our shores from storms and tidal influences.

There is one creature that could help save the reefs-- the humble sea cucumber.

Sea cucumbers are echinoderms from the class Holothuroidea. They are marine animals with a leathery skin and an elongated body containing a single, branched gonad. Sea cucumbers are found on the sea floor worldwide. The number ofholothurian species worldwide is about 1,717. with the greatest number being in the Asia Pacific region. Sea cucumbers serve a useful role in the marine ecosystem as they help recycle nutrients, breaking down detritus and other organic matter after which bacteria can continue the degradation process.

Like all echinoderms, sea cucumbers have an endoskeleton just below the skin, calcified structures that are usually reduced to isolated microscopic ossicles (or sclerietes) joined by connective tissue. In some species these can sometimes be enlarged to flattened plates, forming an armour. 

Image: animals.nationalgeographic.com

Image: seattletimes.nwsource.com

"When they ingest sand, the natural digestive processes in the sea cucumber's gut increases the pH levels of the water on the reef where they defecate," says One Tree Island deputy director, Professor Maria Byrne.

The excrement of this humble creature contains calcium carbonate (CaCO3), which is an essential component of coral.

"To survive, coral reefs must accumulate CaCO3at a rate greater than or equal to the CaCO3 that is eroded from the reef [by ocean acidification]," Maria says.

The waste also provides nutrients to assist coral growth.

One problem is the sea cucumbers are also threatened. Many of these are gathered for human consumption and some species are cultivated in aquaculture systems. The harvested product is variously referred to as trepang, bêche-de-mer or balate. If you ever saw an eviscerated sea cucumber you really have to wonder about the things people eat and like.....  But that is another entry. Given its role in coral conservation, we need to control sea cucumber harvesting to lessen the impact on reef health.

info: http://www.australiangeographic.com.au/journal/sea-cucumber-poo-could-save-great-barrier-reef-ocean-acidification-coral-one-tree-island.htm