Just a FYI- there is NO SUCH a thing as being allowed/not allowed to harvest coral. Selling them is a whole different story, I don't know what the laws are in Belize about this. Most shop owners will say they picked them up dead (hmmm).
Generally, corals are to be preserved and left alone, corals take years and years to grow and provide homes for fishes, there's been a lot of damage from anchoring, net fishing, people who take them for decoration/jewelry and irresponsible scuba divers/snorklers.
Here's an article from the National Geographic on Black Corals-http://news.nationalgeographic.com/news/2001/06/0606_blackcoral.html