IB ESS HL 2.2.28 Ecological Efficiency Question Bank
Calculate and interpret ecological efficiency between trophic levels.
- Syllabus
- First assessment 2026
- Course
- ESS HL
- Level
- HL
Calculate and interpret ecological efficiency between trophic levels.

Figure A sample food chain from a marine ecosystem to show the concentration of persistent organic pollutants (POPs) and the energy within each trophic level
Calculate, as a percentage, the efficiency of energy transfer between zooplankton and herring.
(25/500)×100=5(%);