Group Challenge Bioaccumulation and

Biomagnification

• Significant idea: Top carnivores are most vulnerable to persistent non-biodegradable pollutants in an ecosystem

• By the end of this lesson: a clear distinction between bioaccumulation and biomagnification along with its effects on the food chain trophic levels. A clear explanation on how both bioaccumulation and biomagnification it affects the top carnivores will be made using one of two case studies, Minamata Bay or the polar bears and (PBDE).

• ATL: Thinking

• Making a connection between bioaccumulation and biomagnification with a case study of either Minamata Bay or polar bears and (PBDE)

• https://www.youtube.com/watch?v=J9i6a_NRahg

• Short clip on bioaccumulation and biomagnification

• https://www.youtube.com/watch?v=85I7oPWUuak

• Biomagnification and bioaccumulation explained

Bioaccumulation• Bioaccumulation = when a chemical builds up in a single organism over time

• What types of organisms would be most at risk for bioaccumulation?• Animals that eat more, are larger, and have longer lifespans

As the fish get older, and eat more, they will build up more chemicals in their bodies.

Bioaccumulation

• How does it happen?

• The chemical accumulates because it does not break down easily

• The chemical gets stored in fat cells of organisms.

Biomagnification• Concentration of the chemical

at lower trophic levels may not have much effect

• But, as you go up the trophic pyramid, the highest levels will have very high amounts of the chemical

Biomagnification

• Biomagnification = the tendency of toxins to concentrate in organisms at higher trophic levels.

Biomagnification• How does it happen?

• Pollutants get into the producers (through water or air)

• Small herbivores eat many producers, and may also get the chemical through water.

• Carnivores eat many herbivores, and get even more of the chemical in their bodies. They take in so much of the chemical that it causes disease or death.

Video on Biomagnification of DDT

• https://www.youtube.com/watch?time_continue=2&v=uhiCORNRgzA

Difference between Bioaccumulation and Biomagnification

Same organism has toxin build up in its body over time

Amount of toxin increases in higher trophic levels

Bioaccumulation

Biomagnification