Summary
Persistent toxins like DDT become more concentrated at each higher trophic level.
In depth
Persistent, fat-soluble chemicals (DDT, mercury, PCBs) are not metabolised or excreted and accumulate in tissues. Concentration rises up the food chain: DDT thinned the eggshells of birds of prey and caused declines in eagles and peregrines.
Rachel Carson's Silent Spring (1962) drew attention to it.
It requires persistence, fat solubility and slow excretion. Bioaccumulation is build-up within an organism; biomagnification is increase along food chains.
Example: PCBs concentrate in orcas and polar bears.
Frequently asked questions
What is Biomagnification?
Persistent toxins like DDT become more concentrated at each higher trophic level.
Which area of biology covers Biomagnification, and how advanced is it?
Biomagnification is one of the 54 topics in Ecology. It is rated Intermediate, so it suits learners who already know the core vocabulary. Related topics in this area include Food Chain, Energy Pyramid, Trophic Levels.
Can you give an example of Biomagnification?
Tuna and swordfish carry mercury and are limited in pregnant diets.
What should I learn before Biomagnification?
Work through the Beginner topics in Ecology first, such as Ecology, Ecosystem, Biotic and Abiotic Factors, then return to Biomagnification. Intermediate topics assume the Beginner vocabulary.
What topics are related to Biomagnification?
The closest topics to Biomagnification are Food Chain, Energy Pyramid, Trophic Levels, Food Web. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Biomagnification?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Biomagnification. To practise the whole of Ecology, use the Ecology quiz.
How is Biomagnification different from Food Chain?
Biomagnification: Persistent toxins like DDT become more concentrated at each higher trophic level. Food Chain: A linear sequence showing who eats whom, beginning with a producer. Read both side by side and note what each one explains.
How should I study Biomagnification step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Food Chain and explain the difference aloud. Finally, take the Ecology quiz and come back to this page for any question you miss.