Energy in Marine Ecosystems: Marine Food Chains

1. Energy in Marine Ecosystems:Marine Food Chains Begins with the primaryproducers They are autotrophs (‘self’-‘feeders’) - Organism capable of making organic compounds, Photoautotrophs, such as plants,use solar energy to help make these compounds in a process known as photosynthesis. Primary producers are consumed by primaryconsumers Primary consumers , are heterotrophs(‘other’-‘feeders’)- Organisms incapable of making organic compounds from inorganic material, they obtain their nutrition by consuming autotrophs and derive energy through respiration. Primary consumers are consumed by secondary consumers, a.k.a. tertiaryproducers. And so on…Food chains vary in length.

2. Capture and Flow of Energy The flow of energy through living systems. © 2002 Brooks/Cole, a division of Thomson Learning, Inc.

3. The Cycling of Matter The cycling of matter through living systems. © 2002 Brooks/Cole, a division of Thomson Learning, Inc.

4. Food Chains • Food Chain- Energy and matter move from one organism to another as each eats a lower member and, in turn, is eaten by a higher member

6. Decomposers • Organic matter not eaten by a higher-level consumer is decomposed by decomposers • Break down non-living organic matter into its original components: carbon dioxide, water and nutrients. • When this matter dissolves in the water and is known as dissolved organic matter (DOM). • Decomposers are important to the food web because they regenerate nutrients, which are then used by the autotrophs. • Ex: Fungi, Bacteria

7. Detritus • Dead organic matter in solid form, such as decaying seaweeds, is called detritus. • Detritus is an important energy pathway in marine ecosystems because many organisms feed on it, especially those that live below the euphotic zone. • Marine Detritivores- Worms, sea cucumbers, clams

8. Figure 10.11

9. Trophic Levels • Each ‘link’ in the food chain is called a trophic level. (troph means food) • 1st =Primary Producer • Ex: plants, algae • 2nd = Primary Consumer • Ex: Grazer, herbivores • 3rd = Secondary Consumer • Ex: Carnivores • 4th = Tertiary Consumer, etc… • At each level, detrivores and decomposers are turning biomass into nutrients

11. Food Web • Because organisms consume at various trophic levels, it is really more like a web, not a chain.

13. Figure 10.13

14. Antarctic Ocean Food Web Diatoms, and other primary producers, convert the energy from the sun into food used by the rest of the oceanic community. © 2002 Brooks/Cole, a division of Thomson Learning, Inc.

15. Ecological Efficiency and Ecological Pyramids • About 90% of biomass is lost when transferred from between trophic levels • Ecological efficiency= 10% • As trophic levels increase, biomass decreases • Why there are more squirrels than wolves in the world

16. Ecological Pyramid 3° Cons. 1 g 2° Consumers 10 g Primary Consumers 100 g Primary Producers 1000 g Biomass

19. Figure 10.14b

20. Figure 10.14a

21. Feeding Relationships © 2002 Brooks/Cole, a division of Thomson Learning, Inc.

24. Figure 15.02

25. Pelagic Primary ProducersPhytoplankton- Diatoms

27. Pelagic Primary Consumer

28. Pelagic Primary ConsumerLarvacean

29. Holoplankton

30. Holoplankton- Jelly

32. Meroplankton

33. Nekton

34. Primary Productivity Oceanic productivity is measured in gC/ m2/yr. © 2002 Brooks/Cole, a division of Thomson Learning, Inc.

35. Figure 10.15

36. Figure 10.16

37. Global Primary Production

38. Carbon Cycle

39. Nitrogen Cycle