Deep water coral and their impact on our global bionetwork have only recently been studied, so naturally, we don’t quite know as much about them as we do their shallow water-dwelling brethren. They come from a world of darkness located thousands of feet below the ocean’s surface and can only be explored by the most sophisticated scientific equipment. As the secrets of these desolate invertebrates are uncovered, we continue to gain a better understanding of the important role they play in their surrounding ecosystems. More specifically, conservationists have begun to focus their efforts on analyzing the impact that humans have on the deep-water coral that form the backbone of our ocean’s infrastructure. Before we discuss conservation efforts, however, let’s review the basics of deep water coral.
What Are Deep Water Coral?
These coral are much like their shallow water counterparts; they exist in a variety of colors and provide a home for many of the ocean’s other creatures. They share the propensity to grow into reefs that can stretch for miles. In fact, scientists have documented some coral that stand several meters tall. Their diversity rivals that of tropical coral. Many different species exist with textures ranging from spongey to stone-like, but that’s where the similarities end.
Deep water coral thrives in the most extreme ocean habitats. They prefer to live at depths ranging from 200 to 1,500 meters, tolerate temperatures as low as 30.2ºF, and survive under crippling water pressure. An extreme lack of light means these coral are non-photosynthetic. They lack the symbiotic relationship with zooxanthellae that shallow water species rely on to produce food. Instead, the coral use their tentacles to catch food carried by ocean currents. Their isolated environment also allows for the creatures to remain relatively undisturbed by man or nature, which affords them a lifespan of thousands of years.
Why Are Deep Water Coral Important?
As we mentioned before, deep-water coral make up the backbone of the ocean floor. They provide food and shelter both directly and indirectly to a plethora of species. Small fish use the coral as shelter to hide from predators. Predators, in turn, use the coral as camouflage to stalk their prey. Some obscure species, like ophiuroids (think starfish), can spend their entire life on a branch of coral. These brittle stars eat the coral’s mucus coating for their own nutrition, while simultaneously removing bacteria and other debris from the coral’s surface. So many other species interact with and depend on these coral. It is easy to see how the longevity of deep water coral is so essential in maintaining a balanced ocean ecosystem.
Are Deep Water Coral in Danger?
Yes and no. Deep-water coral face substantial danger from dredge fishing. This kind of fish harvesting uses a net to scrape the bottom of the ocean, pulling up anything in its path. According to the National Oceanic and Atmospheric Administration, however, there are over 1,600 protected marine areas in the United States, and three percent of these are no-take areas designed to protect fragile species and habitats. Altogether, 41 percent of U.S. marine waters are protected in some way. This means that while dredging does affect coral, at least in U.S. waters, most of it is safe.
Perhaps the most significant danger to deep water coral comes from oil spill accidents. On April 20, 2010 the Deepwater Horizon semisubmersible offshore oil rig ruptured, sending approximately 4.1 million barrels of crude oil into the Gulf of Mexico at a depth of 1,520 meters. An ongoing study funded by the Bureau of Ocean Energy Management (BOEM) and the National Oceanic and Atmospheric Administration’s Ocean Exploration and Research program found significant evidence of damaged deep water coral located 11 kilometers southwest of the Macondo well. At the site, 86 percent of the coral colonies showed signs of stress from the oil spill. Forty-six percent of the colonies displayed negative impacts to at least 50 percent of a given colony, and 23 percent of the colonies sustained damage to more than 90 percent of their surface area. The remotely operated vehicle, (ROV) Jason II, found excessive mucus production, decaying tissues, and retracted polyps on coral coated in sludge. The sludge was then confirmed to be from the Deepwater Horizon spill through the use of chemical biomarkers.
As their mysteries unfold, there’s no doubt that deep water coral will continue to be seen as a vital part of oceanic communities. Their slow rate of growth and their extended life expectancy mean that protecting the invertebrates from man-made disasters is very important. When the world’s corals are destroyed, the surrounding ecosystems falter, and the coral won’t be coming back anytime soon.
Fortunately for at-home reef keepers, deep water coral can withstand being removed from their environment and relocated to a tank. These species are a beautiful option for anyone who would like to add diversity to a collection. They are also an excellent conversation starter. If you’re interested in becoming involved in hobby reef keeping or would like to upgrade an existing set up, have a look at our online shop. We carry only the best in reef building components, and we offer a superior level of customer service to match.