One little studied source of variation is the influence of habitat - specific feeding on mercury accumulation in lake fish. (sciencedaily.com)
For some fish, temperature change would bolster growth rates, decreasing mercury accumulation. (scientificamerican.com)
In a study on Amazonian people who ate a lot of fish, the people who had the most fiber in their diet had markedly lower rates of mercury accumulation in the body compared to the low fiber group. (drlaurell.com)