Mercury is a significant heavy metal found in the food supply. Which of the following is the highest source of mercury?

Tuna is known to be one of the highest sources of mercury among commonly consumed fish. This is primarily due to its position at the top of the marine food chain, where larger tuna, especially species like albacore and bluefin, accumulate mercury over time through a process known as biomagnification. As smaller fish that contain mercury are consumed by larger fish, the concentration of mercury increases in the tissues of these larger species.

In terms of consumption, mercury levels can vary significantly between different types of fish, with larger predatory species typically having higher mercury concentrations than smaller, lower trophic level fish like sardines or trout. This distinction underscores the importance of choosing fish based on mercury levels, especially for vulnerable populations, including pregnant women and young children, who are more susceptible to the neurotoxic effects of mercury. Thus, tuna stands out as a fish that should be consumed in moderation due to its mercury levels, making it the highest source of mercury among the options given.