Apart from the fact that pearls comes from oysters and they taste great not many people know much about them. They are grown commercially for their meat as well as the cultured pearls the produce. Since they are in no danger of becoming an endangered species soon - unless the global climate dramatically changes and that would affect more than just oysters. That reminds me of an oyster joke:
One oyster was showing off it's pearl to another oyster. The larger oyster claimed to have the bigger pearl. An argument ensued. Soon they were fighting. The other oysters near them remarked "they're at it again, they are always fighting in bed"
Oysters do carry dangerous organisms and can be a health risk if eaten raw.