As marine pearls become more difficult to find, I wonder if the...

As marine pearls become more difficult to find, I wonder if the major jewellery companies are tempted to secure more supply, by taking shareholdings into the pearl farm companies.
I was reading an old article (2001) where it was indicated that the Paspaley family controls 80 % of Australian pearl production (at that time).
It probably makes sense in the Australian market, where the production is limited by permits.
My understanding is that the Indonesian market is different, as it seems that there is no supply restriction.