These 2 to 3 m tall orange-colored, black coral trees growing near Viosca Knoll in the
Gulf of Mexico are among the oldest living organisms on Earth.
For the first time, scientists have been able to validate the age of deep-sea black corals in the Gulf of Mexico.(ermm interesting) They found the Gulf is home to 2,000 year-old deep-sea black corals, many of which are only a few feet tall.
These slow-growing, long-living animals thrive in very deep waters 300 meters (984 feet) and deeper yet they are sensitive to what is happening in the surface ocean as well as on the sea floor.
“The fact that the animals live continuously for thousands of years.Despite living at 300 meters and deeper, these animals are sensitive to what is going on in the surface ocean because they are feeding on organic matter that rapidly sinks to the sea floor. Since longevity is a key factor for population maintenance, recovery from a disturbance to these ecosystems, natural or manmade, may take decades to centuries.”
Reliably age dating the corals, as done in the recent study, is a critical step in using them as natural archives of environmental change.
Like shallow-water coral reefs, deep-sea coral-reef ecosystems are among the most diverse and productive communities on Earth, providing shelter and feeding grounds for commercial and non-commercial fish species and their prey, as well as breeding and nursery areas. Activities that affect both the seafloor and the surface ocean, such as certain methods of petroleum exploration and commercial fishing, can impact these ecosystems.
Black corals grow in tree- or bush-like forms. Scientists confirmed that black corals are the slowest growing deep-sea corals. They grow 8 to 22 micrometers per year as compared to the shallow-water reef-building coral, typically found in tropical areas like Hawai‘i, which grows about 1 mm per year, or 65 times as fast as black coral.
“The flexibility and shiny luster of black coral have made it a precious commodity in the coral jewelry trade and international trade is regulated by the Convention on International Trade in Endangered Species of Wild Fauna and Flora. “In fact, black corals have been harvested for centuries to create charms; the scientific name of the order to which black corals belong, ‘Antipatharia,’ comes from Greek roots meaning ‘against suffering.’”
Like trees, black corals exhibit radial growth, with the oldest skeletal material found in the center and successfully younger material building out toward the edge. Viewed in a horizontal cross section, the black coral’s growth bands resemble tree rings.
