On 2005-12-31, la gripa colombiana > wrote:
> I've started to like fish sauce, but I wonder how safe it is since
> the entire ocean ecosystem is contaminated with mercury.

Concentration of mercury increases as it moves up the food chain.
Small fish are eaten by larger fish which are, in turn, eaten by
larger fish. So, you'll see lower concentrations in anchovies than,
say, swordfish or tuna.

nb