This process begins with the natural incorporation of lead-210 from seawater into the coral skeleton. As the coral grows like a tree, laying down growth rings, the radioactivity of lead-210 decreases from the youngest to the oldest part of the skeleton.
So far, age determination studies have found that deep-sea corals can attain ages anywhere from a hundred to perhaps thousands of years. 2005b : Lead-210 dating bamboo coral (family Isididae) of New Zealand and California.
Age and growth of deep-sea corals is typically determined from outgrowth studies in the field, growth-zone counts in the skeletal structure, a radiometric technique (e.g., lead-210 dating), or a combination of these techniques. Third International Symposium on Deep-Sea Corals: Science and Management.
Marine Scientist/Research Coordinator Monterey Bay National Marine Sanctuary When most people think of corals they imagine tropical waters and snorkeling.
They are surprised to learn that corals are also found throughout the world in the ice-cold, dark waters of the deep ocean.
Now a group of scientists and others have signed a statement calling the reef, the existence of which was only revealed last year, to be protected.
The signatories include Sylvia Earle, the former head of the US National Oceanic and Atmospheric Administration, as well as other scientists from the US, Brazil, Colombia, the UK, Spain, Australia and the Philippines.
The reason lead-210 activity decreases is because it slowly decays (a process called radioactive decay) at a known rate — in this case, a half-life of 22.26 years.
(A half-life is the time elapsed for the radioactivity of a substance to fall to half its original value.) To measure this change in radioactivity and relate it to age, researchers take a series of samples from the edge of a skeletal cross section to the center.
Cold-water (or deep-sea) corals are part of the taxonomic group called Cnidaria, and they are related to animals like sea anemones and jellyfish.
They can live as individuals or as colonies that form extensive reefs.
This line of work has been further applied to another species of bamboo coral from New Zealand and related to possible indicators of ocean climate change (Neil et al. This trend continues to approach an activity of zero (or supported levels) in an exponential manner.