Salmon is not known as a high-risk fish for mercury. The risk of salmon with high-mercury content is usually from high-population and pollution in some lakes and rivers where the salmon begin their lives.
Our Seabear salmon products test at <5.67 mcg/serving. Usually with a result of "<", the indication is that the test is not able to detect levels lower than the level shown.
The rivers in Alaska where most of the fishing is done have very few people living near them - usually towns with populations of less than 5000. There is very little industry in the area and this makes the rivers an excellent environment for salmon to call home.