SF Bay Estuary Ecology Notes

1. SF Bay Estuary Ecology Notes

2. I. What is Ecology? A. Definitions: 1. Ecology- The study of the interactions of organisms with one another and their environment. 2. Ecosystem-a self-sustaining collection of organisms and their environment. 3. Estuary-a partially enclosed body of water where fresh river water mixes with salty ocean water.

3. II. The ABC’s of Ecology • A=Abiotic Factors (non-living) 1. Factors in SF Bay include: • Temperature • Water • Sunlight • Wind • Salinity: - varies from 0ppt to 35ppt depending on the location in the estuary. • Rocks and soil • Catastrophes: fires, floods, earthquakes

4. B. B=Biotic Factors (living) 1. Factors in SF Bay include: • Plants, Animals, Protists, Fungi, Bacteria 2. Organisms are classified as follows into trophic levels (“feeding” levels): • Producers- organisms that make their own food from inorganic substances • Consumers-organisms that receive their energy from consuming other organismsherbivores-eat plants carnivores-eat herbivores and each other omnivores-eat both plants and animals • Decomposers -organisms that obtain their energy from non-living organic matter

5. C. C=Cultural Factors (human impact) 1. Factors in SF Bay include: • Endangered plants and animals • 30 species of endangered plants and animals use the Estuary during at least a part of their lives. • Diversion of Fresh Water • ~50% annual flow of fresh water is diverted for agriculture. • Waste and Run-Off • Almost 200 industry sites dump wastes into the Estuary each year-including 300 tons of trace metals. Urban runoff contributes even more pollutants. • Destruction of Tidal Marshes - 97% of the tidal marshes have been destroyed or altered.

6. III. Energy in the Ecosystem A. The Sun is the Source of Energy 1. Producers convert the sun’s energy into chemical energy through a process called photosynthesis. 2. Equation: Carbon Dioxide + Water = Glucose + Oxygen6CO2 + 6H20 = C6H12O6 + 6O2

7. III. Energy in the Ecosystem Food Chains and Food Webs 1. Consumers receive energy by eating producers or other consumers. 2. A food chain is a diagram showing the flow of energy through individual organisms. 3. Example: diatoms sea lion shrimp fish Trophic level Source Producers 1º Consumers 2º Consumers Top consumers

8. III. Energy in the Ecosystem Food Chains and Food Webs 4. A food web is a diagram illustrating the flow of energy through an entire ecosystem. 5. Example: *Arrows show direction of energy flow Figure 47-21

9. III. Energy in the Ecosystem • Ecological Pyramids -An ecological pyramid represents energy relationships among trophic levels. • Pyramid of Energy Less Energy Fewer Organisms More Energy More Organisms Figure 47-16 • 10% rule: • Only 10% of energy can be transferred to the next energy level! • 90% of energy is used by organism or lost as heat

10. III. Energy in the Ecosystem • Ecological Pyramids 2. Pyramid of Biomass and Numbers Figure 47-16

11. IV. Questions to Consider 1. Suggest an explanation why there are fewer lions than zebras on the African plains. *90% of energy is lost at each level so there isn’t as much energy available for top consumers. Also, it is easier to get food as a producer so population numbers are higher. More agricultural land would be available to provide food for the growing human population if humans did not eat meat. Explain why. A person gets the same amount of energy from eating the same amount of either meat (cow) or grain. But due to the 10% rule, much more grain will be used if the person eats the cow for energy. Making more grain uses land and resources that could be available to feed more people. MORE--> Person 1 energy Grain 10 energy or Cow 10 energy Grain 100 energy

12. IV. Questions to Consider 3. Are there other implications to the fact that only 10% of energy is passed to the next trophic level? YES. Though 90% of energy is lost as heat, toxic chemicals are not lost and they accumulate in living tissue. This means the effect of pollution is much greater for top level consumers. This process is called BIOACCUMULATION. Person 1 energy 10 or 100 pesticide Grain 10 energy 10 pesticide For example, if each unit of grain is polluted with 1 unit of pesticide, the person who eats the grain directly gets only 10 units of pesticide. The person who eats the cow gets 100 units! or Grain 100 energy 100 pesticide Cow 10 energy 100 pesticide

13. V. Summary Reading questions 4. Summary: p. 193 1. LIGHT (PHOTOSYNTHESIS), CHEMICAL BONDS (CHEMOSYNTHESIS) 2. ENERGY FLOW: PRODUCERS  CONSUMERS 3. 10% OF ENERGY IS TRANSFERRED FROM ONE TROPHIC LEVEL TO THE NEXT. 4. RELATIONSHIP: AUTOTROPH (PRODUCER) EATEN BY HERBIVORE. OMNIVORE EATS BOTH. 5. 5TH CONSUMER 0.001% 4TH CONSUMER 0.01% 3RD CONSUMER 0.1% 2ND CONSUMER 1% 1ST CONSUMER 10% PRODUCER 100%

14. V. Other Reading Info 1. Source Integrated Science, p. 183-193 2. Vocabulary: ecology biosphere species populations communities ecosystem biome autotrophs producers photosynthesis chemosynthesis heterotrophs With definitions! If any of these not listed, please add the word. 3. Outline I. Interactions and Interdependence: Ecology II. Levels of Organization III. Ecological Methods IV. Producers, Consumers V. Feeding Relationships VI. Ecological Pyramids Does not have to be in this exact format, but should have further information! consumers herbivores carnivores omnivores detritivores decomposers food chain food web trophic level ecological pyrimid biomass

15. VI. SF Bay Scorecard Scores from 0 - 100Source: The Bay Institute (bay.org, 2005)