Coral is simply amazing. Most closely associated with the coral reefs of warm waters, many people don’t know that coral can thrive in cold water as well.
In southern California we have coral, the kind that thrives in water temperatures between 29 and 55 degrees F, and lives deep in the sea (although can be in some shallow areas as well, much to the delight of so-cal divers). Scientists tend to call them “cold water corals”, although they can be found in tropical climates (usually much deeper, obviously, where the water is cooler).
Corals are awesome. They make their own exoskeleton out of calcium carbonate. Some corals have the power to turn sunlight into food (which you’ll remember hopefully from elementary school as photosynthesis) although for this to occur, there must be sunlight. Corals also use stinging tentacles to catch their own prey (like plankton) from the water passing over them. In a sense, this makes them both an animal and a plant, which is really cool, although not all corals have this dual ability.
Cold water coral that lives really deep doesn’t have the advantage of the sunlight to help make food, so it must rely on its own sticky fingers to catch food coming by. In a way, this has made it fiercer and more self-sufficient. Cold water coral can live very, very long. Radio carbon dating has estimated one colony at 8,000 years of age….older than any known warm water coral colony. It also grows and grows and grows. The Great Barrier Reef of Australia is often thought to be the longest reef on earth (1200 miles approx) , but if cold water reefs are taken into account, some cold water reefs can extend for 2800 miles. A Lophelia reef off Norway’s coast covers as much ground as Manhattan (although it is probably much less grumpy and rushed, and wears a lot less black).
(“For nine miles along a submerged ridge, the corals rise in lumpy hillocks that spread out 100 yards or more, resembling heaped scoops of rainbow sherbet and Neapolitan ice cream. The mounds, some 100 feet tall, sprout delicate treelike gorgonians that sift currents for a plankton meal. Fish, worms and other creatures dart or crawl in every crevice. This description could apply to thousands of coral reefs in shallow, sun-streaked tropical waters from Australia to the Bahamas. But this is the Sula Ridge, 1,000 feet down in frigid darkness on the continental shelf 100 miles off Norway’s coast.”-Andrew Revkin)
Why is coral important? Coral forms underwater gardens, which are as lovely as they sound. They are food and shelter for innumerable creatures, and add depth and diversity to the ocean. Reefs offer shelter as nurseries in some areas that would be a vast and sandy wasteland without it.
Threats to cold water corals include deep-sea trawling, wherein fishing vessels use weighted nets to drag along the bottom of the ocean, destroying anything in their wake. Like their warm water cousins, ocean acidification is also a threat. Increasing amounts of CO2 in the atmosphere mean the ocean is absorbing larger amounts of CO2. This makes the ocean more acidic: causing harm, or death to corals and many other forms of sea life.
So now you know, cold water coral exists, it is lovely and vast and tiny, and fierce and fragile all at the same time. I’ll end with a quote now.
“In the end we will conserve only what we love; we will love only what we understand; and we will understand only what we are taught.” (Baba Dioum, 1968.)
PS anybody at Farnsworth this weekend, keep your eyes peeled for some coral!
Information learned from this WONDERFUL article. If you have the time, read it.
Also, for more brilliant photos from Michael Zeigler, please see Sea in Focus.