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Difficulty: MediumPollution Types, Causes, Effects, and Control

An industrial manufacturing facility releases synthetic, fat-soluble pesticide residue into a nearby lake ecosystem. The ecosystem supports a food chain consisting of phytoplankton, zooplankton, plankton-eating minnows, and fish-eating osprey. Which of these organisms will exhibit the highest concentration of the pollutant per unit biomass due to biomagnification?

  1. Fish-eating ospreyAnswer
  2. B
    Phytoplankton
  3. C
    Zooplankton
  4. D
    Plankton-eating minnows

Answer

Fish-eating osprey exhibit the highest concentration of the pollutant due to biological magnification at the apex of the food chain.
Biological magnification (or biomagnification) occurs when synthetic, non-biodegradable, fat-soluble chemicals pass through an ecosystem's food chain. Because these pollutants are not readily broken down or excreted, predators absorb all the accumulated toxins stored in the tissues of the many prey organisms they consume over their lifespan. Consequently, apex predators located at the highest trophic level (such as the fish-eating osprey) concentrate the highest dosage of toxic material per unit body mass.

Step-by-Step Solution

1
Identify the chemical property of the pollutant and the trophic structure.
The pollutant is non-biodegradable and fat-soluble, passing from Phytoplankton (producers) → Zooplankton (primary consumers) → Minnows (secondary consumers) → Osprey (tertiary/apex consumers).
Persistent fat-soluble pollutants cannot be easily metabolized or excreted by organisms.
2
Apply the principle of biomagnification across trophic levels.
Organisms at each successive trophic level consume large quantities of biomass from lower levels, accumulating and concentrating the ingested toxins in their fatty tissues.
Energy is lost at each trophic level, but persistent toxins are retained and amplified up the food chain.
3
Determine the organism at the highest trophic level.
The fish-eating osprey is the apex predator in this aquatic food chain and will retain the highest toxin concentration.
Apex predators occupy the top trophic position where bioaccumulation reaches its peak.

Key Concept

Biomagnification of persistent non-biodegradable pollutants across trophic levels
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Topics

Pollution Types, Causes, Effects, and Control

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