As I understand it, the main harvesting months in the South Seas...

As I understand it, the main harvesting months in the South Seas are June-August; lower sea temperatures reduce oyster nacre production during that period. That’s consistent with company reports a year ago, when harvest volumes fell from 146k in the September quarter to ca 58k in the December quarter. Pearl stocks at 30 June were 100k (Annual Report), so the company may have had up to 200k pearls available for sale in the recent quarter. A year ago, the company undersold in calendar Q3 in order to carry forward inventory to Q4, to offset the seasonally low harvest that quarter. In fact, sales in Q4 exceeded those in Q3. This year’s September auction sold only 75k pearls, so it may be that the company is repeating that pattern again this year - underselling in Q3 and having a larger sale in Q4, perhaps to exploit a sellers’ market?
Even so, as I’ve mentioned before, the 75k sales in the September auction were low in comparison to an average quarter of 125-140k, suggesting sales through private buyers etc are increasingly important. (In past years, auctions were much more frequent than one per quarter.) That would be consistent with non-auction sales attracting better prices than excessive numbers of auctions.