AP Environmental Science Unit 8 Topic 8.7

POP Tracker Lab

Trace a persistent organic pollutant from release into plankton, fish, and a human consumer, then use visual evidence to explain ecosystem effects.

Core Idea

POPs create ecosystem risk because they persist, move, and concentrate in living tissue.

Persistent organic pollutants such as DDT and PCBs are synthetic carbon-based chemicals that resist breakdown. Many are fat-soluble, so organisms store them in fatty tissue and pass them through food webs.

1. Persistence

They remain for years.

High chemical stability means a POP can stay in soil, sediment, water, or organisms long after release.

2. Fat Solubility

They collect in tissue.

Fat-soluble chemicals are retained in organisms more easily than water-soluble pollutants.

3. Food Webs

They magnify upward.

Predators eat many contaminated prey, so concentration often rises at higher trophic levels.

4. Transport

They travel far.

Wind, runoff, water currents, and migrating organisms can move POPs away from the original source.

Common APES Misconceptions

Separate the terms before running the model.

Bioaccumulation is inside one organism.

A pollutant builds up when intake is faster than elimination.

Biomagnification is across trophic levels.

Concentration increases from prey to predators in the food web.

Distance does not remove risk.

A POP released far away can still affect an ecosystem after transport and redeposition.