Nathan and Kenneth 8.8 Biomagnification

Bioaccumulation

Absorption and concentration of compounds (especially fat-soluble ones like POPs) in the cells & fat tissues of organisms

Biomagnification

⛰️ Increasing concentrations of fat-soluble compounds like methylmercury and POPs in each level up the trophic pyramid or food web/chain

How do POP levels accumulate in a food chain?

Because of the 10% rule, organisms at each successive trophic level need to eat more and more biomass to receive enough energy, leading to higher and higher POP levels over their lifetimes

Biomagnification (methylmercury)

Mercury is emitted from burning coal & by volcanoes, carried by wind, and deposited in water where bacteria convert it into toxic methylmercury
Taken in by phytoplankton & biomagnified at higher trophic levels

Biomagnification (DDT)

DDT was banned in many developed nations but still persists in the sediments of many bodies of water
Reach highest levels in top predators, esp. predatory birds like eagles & osprey
Causes thinning of the eggshells in these birds
Linked to a massive pop. decline of bald eagles in US, which prompted the passage of the Endangered Species Act (73')

human effects of bioaccumulation and biomagnification

issues with reproductive, circulatory, nervous systems