What is growing on this little turtle??

I photographed this turtle in Maho Bay, St. John. It has some strange growths on it that sort of resemble barnacles. I think they settled and grew over just a few weeks. I would like to know if anyone can tell just what these are. Another small turtle in this bay has no growths at all. I have never seen anything like this, or any fibrop. on any of the numerous greens around St. John.