They’re called Ama divers. It’s an ancient Japanese tradition where (mostly female) divers bring oysters from the ocean floor that contain cultured pearls. At least that’s what they told us at SeaWorld in northeast Ohio. We took the park management at their word on it.
This was my area of SeaWorld of Ohio. I spent several summers in Seaport Village, a large open building in a Japanese style. There was the pearl diving show, the oyster counter, and then the jewelry shop. There were some places in SeaWorld of Ohio where you might walk in and a single person would be in the shop to help you. At Seaport Village, there were usually a dozen employees, plus the divers. New guests wandered in all the time to see the next show. Through the open doors from across the lake you could hear the people screaming on the Geauga Lake rides. The wind blew through and rang the chimes. We were far from the front of the park and were perhaps a bit lax when it came to following park policies. At least some of the time.
If you never went and saw it for yourself, too late. You missed it.