2.2.18—Non-biodegradable pollutants

Bioaccumulation increases a substance within one organism; biomagnification increases its concentration at higher trophic levels.

A persistent, fat-soluble pollutant can enter faster than an organism excretes it. Predators then consume many contaminated prey, concentrating the pollutant through the food chain.

Small fish each retain a little mercury; a tuna eating many fish can end with a higher tissue concentration than any single prey fish.

Bioaccumulation: the change is within one organism over time, not across trophic levels.

Biomagnification is not simply pollution becoming stronger in water; it is a trophic-level concentration pattern.