8.8 Bioaccumulation and Biomagnification

• What is the definition of bioaccumulation?

  Accumulation of toxic substances
• Organisms absorb toxic substances at a rate exceeding their elimination rate in bioaccumulation.
• Toxic chemicals accumulate within the organism's tissues
• What is the definition of biomagnification?

  Increase in toxin concentration
• Order the following steps in the biomagnification process:

  1️⃣ Toxins accumulate in prey

  2️⃣ Predators consume contaminated prey

  3️⃣ Toxin concentration increases at each trophic level
• Which organisms in a food chain have the highest concentrations of toxins in biomagnification?

  Top predators
• $Concentration_{\top predators} > Concentration_{prey} > Concentration_{producers}$ illustrates that toxin concentration decreases from top predators to producers
• What is direct uptake as a mechanism of bioaccumulation?

  Absorption from the environment
• Dietary uptake occurs when organisms consume contaminated food sources in bioaccumulation.
• Match the bioaccumulation mechanism with its description:

  Direct Uptake ↔️ Organisms absorb chemicals from their environment

  Dietary Uptake ↔️ Organisms consume contaminated food

  Trophic Transfer ↔️ Higher trophic levels accumulate toxins
• Why do organisms accumulate toxic substances in their tissues during bioaccumulation?

  Faster absorption than excretion
• Absorption Rate > Excretion Rate</latex> illustrates that the absorption rate of toxic substances is greater than the excretion rate.
• Each trophic level in a food chain shows decreasing concentrations of toxins in biomagnification.

  False
• What is dietary uptake in bioaccumulation?

  Consuming contaminated food
• Concentration_{\top predators} > Concentration_{prey} > Concentration_{producers}</latex> illustrates that biomagnification leads to higher toxin concentrations in top predators
• Match the biomagnification mechanism with its example:

  Trophic Transfer ↔️ Mercury accumulation in fish

  High Accumulation ↔️ Top predators accumulating pesticides

  Food Chain Dynamics ↔️ PCB concentrations in seals
• Mercury is a common pollutant that bioaccumulates in aquatic organisms.
• Which pollutant biomagnifies in food chains and affects birds and marine mammals?

  DDT
• Bioaccumulation is the process by which organisms absorb toxic substances at a faster rate than they can excrete
• In bioaccumulation, the absorption rate is greater than the excretion rate.
• Which toxic substance can accumulate in fish, posing a risk to humans?

  Mercury
• Biomagnification is the process where the concentration of toxic substances increases at each higher trophic level in a food chain
• Top predators in a food chain have the highest concentrations of toxins due to biomagnification.
• What is the direct uptake mechanism of bioaccumulation?

  Absorption from the environment
• Trophic transfer is another term for biomagnification.
• The primary mechanism of biomagnification is trophic transfer
• What are the impacts of mercury (Hg) on ecosystems?

  Toxic to nervous system
• Match the pollutant with its primary impact:

  Mercury (Hg) ↔️ Toxic to nervous system

  DDT ↔️ Disrupts endocrine systems

  PCBs ↔️ Carcinogenic effects
• Order the following impacts of bioaccumulation and biomagnification on ecosystems:

  1️⃣ Wildlife Health Issues

  2️⃣ Food Chain Disruption

  3️⃣ Human Health Risks

  4️⃣ Biodiversity Loss
• What is an example of wildlife health issues caused by bioaccumulation or biomagnification?

  DDT affecting eagles
• Mercury contamination in fish is a case study of bioaccumulation
• The concentration of toxins decreases at each higher trophic level in a food chain.

  False
• What is biomagnification?

  Increase of toxins in food chains
• Trophic levels in a food chain show decreasing concentrations of toxins.

  False
• Toxic substances in biomagnification are often difficult to excrete
• Which organisms have the highest concentrations of toxins in biomagnification?

  Top predators
• What are two examples of biomagnification?

  Mercury in fish, DDT in birds
• Primary pathways of bioaccumulation

  1️⃣ Direct Uptake

  2️⃣ Dietary Uptake

  3️⃣ Trophic Transfer
• How do organisms accumulate chemicals through direct uptake?

  From their environment
• Dietary uptake involves consuming contaminated food sources, such as herbivores eating plants contaminated with pesticides