OCN 201 Thirteenth Reading Discussion Questions

Biological Productivity and Energy Transfer

Trujillo and Thurman - Chapter 13

13.1 What Is Primary Productivity?

1. Define primary productivity. (Also see p. 530)

2. Define biomass. (Also see p. 518)

3. Give the percentage of Earth's biomass that depends on photosynthesis to create organic matter.

Measurement of Primary Productivity

4. Explain how scientists measure primary production using satellites. (Also see figs. 13.5 and13.6)

Water Color and Life in the Oceans (p. 376)

5. Define eutrophic and oligotrophic. (Also see fig. 13.5, and pp. 522 and 528)

Why Are the Margins of the Oceans So Rich in Life?

6. Explain why coastal regions general are eutrophic, whereas open-ocean waters generally are oligotrophic. (Also see fig. 13.5)

How Are Energy and Nutrients Passed Along in Marine Ecosystems? (p. 389)

7. Define ecosystem. (Also see p. 521)

8. Give the two most important commodities in an ecosystem.

Flow of Energy in Marine Ecosystems

9. Explain why energy is not recycled in an ecosystem: energy flow is unidirectional. (Also see figs. 13.15 and 13.19)

10. List the three basic categories of organisms in an ecosystem. (Also see fig. 13.15)

11. Define producers, consumers, and decomposers. (Also see pp. 519, 520, and 530)

12. Define herbivores, carnivores, omnivores, and bacteriovores. (Also see pp. 518, 519, 524, and 528)

13. Define detritus. (Also see p. 521)

Flow of Nutrients in Marine Ecosystems

14. Describe the cycling of nutrients (mass) in an ecosystem. (Also see fig. 13.16)

What Oceanic Feeding Relationships Exist?

15. Explain why the producers' biomass is much greater than the consumers' biomass. (Also see fig. 13.21)

Feeding Strategies

16. Describe suspension feeding, deposit feeding, and carnivorous feeding. (Also see fig. 13.17, and pp. 520 and 533)

Trophic Levels

17. Define trophic level. (Also see fig. 13.18)

Transfer Efficiency

18. Define gross ecological efficiency (ecological transfer efficiency). (Also see figs. 13.18 and 13.19, and p. 523)

19. Explain why the average ecological transfer efficiency is only about 10%. (Which processes uses most of the energy?)

20. Explain the advantage of feeding at the first or second trophic level. (A critical-thinking question)

Food Chains, Food Webs, and the Biomass Pyramid

21. Explain how low ecological transfer efficiencies limit the number of trophic levels in an ecosystem.

22. Define food chain. (Also see figs. 13.19 and 13.20, and p. 522)

23. Define food web. (Also see fig. 13.20 and p. 522)

24. Explain why food webs general are more realistic feeding models, compared to a food chains. (Also see fig. 13.20)

25. Define biomass pyramid. (Also see fig. 13.21 and p. 518)

26. Use fig. 13.21 to determine how many kilograms of phytoplankton are required to produce 1 kg of tuna (bonito), given a 10% ecological transfer efficiency.