That's an interesting article Jeremy. I would have thought marine biologists would have known ths for a while though, since nacre production in Pinctada fucata martensii has always been effected by water temperature (particularly rapid crystal formation in warmer water) and has been an obstacle for chinese akoya production.
Natural Pearl Sciences
Senior Pearl-Guide.com Pearl Expert
Tofino, BC Canada
Temeprature is the overall factor in determining a lot of things oceanic. In warm weather, shellfish are able to digest larger organisms. In winter, the animal's ability to uptake and digest these are greatly inhibited. Beside that, there is a lot less food in the water by volume in winter anyway. It might not be so evident in the tropics, but up here where the seasons are more extreme, shellfish will uptake calcium from their own shells (and yes... pearls) when not available in food. Winter harvesting and grafting must be done with greater care as to not crack or break the shells.