The mercury content is Salmon is very low and low enough to not worry about unless you consume too much salmon which would be nearly impossible.
Salmon is good for you but just avoid eating the Salmon every single day and eat other foods as well besides the Salmon just to be safe.
You can get tested for mercury if you think you've consumed too much Salmon but rarely does someone get sick and rarely does someone get mercury poisoning from eating too much Salmon.
Still I would not be able to eat enough Salmon for it to be a problem because unless I had nothing else to eat I would get sick of eating the same thing everyday and that goes for Salmon as well.
So I wouldn't worry about and enjoy the Salmon because it does provide other health benefits.