Fish is also an integral part of world cuisine and fishing is one of the major professions the world over. Which is why, when you think of having fish, you do not naturally connect it mercury pollution.
Mercury pollution have contaminated waters, be it from the rivers or the lakes, estuaries or wetland to such an extent that it is very necessary to create an awareness among people regarding this matter. Because mercury, more than the level that is agreeable to our human body, starts acting as a neurotoxin once it enters the body and starts interfering with the functions of the nervous system as well as the brain.
Which is why, it is highly necessary that one knows which fish to eat and which to avoid.