Question

which fish likely contains the highest concentration of mercury?
a. farm - raised tilapia
b. swordfish
c. cod
d. salmon

Explanation:

Mercury concentration in fish is related to their trophic level (position in the food chain) and lifespan. Swordfish are large, long - lived, and top - predators, which means they accumulate more mercury over time and through biomagnification (the process where toxins increase in concentration as they move up the food chain). Farm - raised tilapia, cod, and salmon are either lower in the food chain, have shorter lifespans, or are farm - raised with less exposure to mercury - rich environments compared to swordfish.

Answer:

b. Swordfish