However, because of the presence of higher levels of mercury in some fish there are a few types you should limit in your diet, especially if you are pregnant. (thebodydietetics.com)
As in: Stop burning coal for cleaner air and less mercury in the fish we eat. (nwei.org)
You may have heard concerns regarding mercury in fish, but eating salmon once or twice a week will not harm your baby. (momming.com)