Round 1: Turn & Talk with your groups about the video above: 

What happens to the amount of heavy metals, toxins and pesticides in the flesh of organisms as we go up the trophic levels?

Round 2: Turn & Talk 

Round 2: Extend the conversation with a 2nd Turn & Talk response to the video using one or more of the following terms:

Round 3: Turn & Talk for a 3rd time creating a series of three statements using the following set of conjunctions: 

“Because… But… So…”

Example: Mr. Pinho is tired BECAUSE he was up late making an awesome lesson for his students, BUT it's ok since they appreciate him SO it was worth

Biomagnification: Toxins Moving Through the Food Chain

Biomagnification is the process in which toxins build up in living things as they move higher up a food chain. These toxins often come from pollution that enters soil or water. They do not break down easily, so once they are in the environment, they can remain there for a long time. Even though the amounts may start out small, they become more dangerous as they pass from one organism to another.

The process usually begins with tiny producers like algae or plants. When toxins enter the water, algae absorb them along with nutrients. Small fish then eat a lot of this algae, taking in all of the toxins stored in it. Each time the small fish eats more algae, the toxin levels inside its body increase.

Next, larger fish eat many of the smaller fish. Because the toxins stay stored in body tissues, especially in fat, the bigger fish end up with an even higher concentration of toxins. By the time a top predator eats those large fish, the toxin level in its body can be extremely high. This is why the highest-level predators in an ecosystem are the most affected.

A well-known example of biomagnification involves a chemical called mercury. Mercury pollution often comes from coal-burning power plants and enters lakes and oceans through rainfall. Small aquatic organisms absorb the mercury, and it climbs the food chain through fish such as tuna and swordfish. People who eat a lot of these large fish can also be affected by the mercury stored in their tissues.

Biomagnification is a serious environmental issue because it can harm both wildlife and humans. Top predators like eagles, whales, and polar bears are especially vulnerable because they eat animals that have already stored large amounts of toxins. When these toxins build up, they can interfere with growth, reproduction, and survival. Reducing pollution and protecting waterways are important ways to limit biomagnification and protect ecosystems.