Well, apparently I found a treasure-trove of them! (but then, I AM a pirate, after all).
I’m so glad these shells are virtual, or I definitely would have many angry islanders after me for pillaging their shores. This way, you can have your very own puka shell set without any environmental impact! Available at the AZE Jewelry Designs Main Store!
Quick note: These puka shells are unrigged mesh, so they are resizeable and can be set to any avatar attachment point. Always make a copy of the original first, just in case.