[Slraep]

Hi Douglas,

I would very much appreciate any info you can find and share.

I only know a bit about the lead contamination. If an akoya oyster is purposefully exposed to high doses of lead for a short period, there seems to be no significant contamination. The bivalve probably detects the lead and goes into anaerobic mode for a while. On the other hand, if the exposure is natural and of a prolonged duration then most of it can be detected in the shell. High levels of lead for prolonged periods will impead biomineralization. The molluscs will not grow. Low levels of lead for prolonged periods will actually do the opposite and speed up shell growth.

I know of potassium, and magnesium as a metallo-protein, affecting the colour of nacre to a certain degree, but I have no idea if any of the said contaminants are porphyrin based either.

Mercury contamination seems to affect a mollusc's immune response. Thulium seems to come from illegally dumped mercury. If I'm not mistaken, thulium is added to mercury and used in heavy duty thermometers in northern weather stations. Someone is either illegally recycling the mercury from these or dumping the used material into the ocean. Probably the former because certain dental amalgam mixtures have been found to contain traces of thulium. There really is no limit to what man will do for a buck.

Slraep