Like I said: Im no alarmist when it comes to wild caught sea food, and will eat a fair share of raw fish without hesitation..and honostly agree that the sea food mercury connection is primarily bunk.
That understood, I will play the devils advocate and proclaim that it is a baseless assumption that Mercury Toxicity isn't an issue, since it is not diagnosed or reported on. Also when talking of toxicity , it is almost never as simple as Identifying just one element which has become out of balance. Mercury in ocean fish is much less of a problem because of the mitigating factors like selenium and other protective trace ocean minerals....than mercury which comes from human pollution of farm land and fresh water, especially in areas where minerals like selenium are totally depleted from the soil.
Its primarily a local environmental issue, so no broad sweeping claims that apply to all can be made. Certain geographical areas such as those inundated with coal burning power plants, industrial centers, or mining operations have higher than average levels of Mercury in the soil and fresh water streams and rivers. The people living in these areas would likely be exposed to higher levels in the local food and water than what the indigenous fishing tribes would ever have to deal with in eating ocean fish.
Studies be damned.....Testing is extremely difficult, and what is considered safe levels, may still cause subtle yet very real detrimental effects to health and well being.