Yes, on account of a variety of factors such as "the type of fish, size, location, habitat, diet and age." Large fish that are at the top of the food chain tend to have some of the highest mercury levels based on the natural accumulation of mercury as you go up the food chain. You can check out more information on this topic and which fish have the highest/lowest amount of mercury at the following sites:

https://www.betterhealth.vic.gov.au/health/healthyliving/mer...

https://www.fda.gov/food/metals-and-your-food/mercury-levels...

https://en.wikipedia.org/wiki/Mercury_in_fish