1. Human Impact
Unit 3

2. Algae

3. Algae basics the base of the food chain (largest producer)
produces 70-75% of O2 for the earth’s atmosphere and earth’s water
can be unicellular (1 cell) or multicellular

6. Normal algae cycle reproduce + create O2
algae grow, photosynthesize to create O2
Plenty of O2 for aquatic life, and releases into air
% die in winter, aerobic bacteria break down the dead material, use up O2
nutrients released by bacteria, reabsorbed by algae, cleans water, causes succession

7. lakes/ponds are transformed

8. A healthy pond begins to have aquatic vegetation; other inhabitants die, increasing organic matter, and it becomes shallower.

9. possibly a marsh

10. Algae cycle + human impact = eutrophication
Eutrophication: is a natural, slow-aging process for a water body, but human activity greatly speeds up the process.
Water acquires a high concentration of nutrients, especially phosphates and nitrates. These typically promote excessive growth of algae. As the algae die and decompose, high levels of organic matter and the decomposing organisms deplete the water of available oxygen, causing the death of other organisms, such as fish.

11. Human Activities and Nutrients

12. Algae cycle + human impact = eutrophication
Algae reproduce + create O2
Tons of dead algae
Too much algae grows, photosynthesize to create O2
% die in winter, aerobic bacteria use up all of O2
No O2 left for fish and toxic gases
Toxic anaerobic bacteria take over, create CH4 and H2S
nutrients released by bacteria, reabsorbed by algae, toxic stuff added, succession
Nutrients added by human activities

13. Classifying water sources
new
bigger, deeper
low nutrients
low biodiversity
cold, clear
EX: great lakes
old
shallow
warmer, cloudier
green algae
high nutrients
high biodiversity
EX: farm pond

14. Eutrophication

15. Eutrophication

16. Eutrophication

17. Eutrophication

18. Eutrophication

19. Different Types of Algae
green algae
contains chlorophyll a, b (green color) which captures light to create energy

20. brown algae do photosynthesis, but use chlorophyll c (brown)
diatoms (unicellular) are similar

21. Diatoms
unicellular organisms with yellow-brown chloroplast that enables them to photosynthesize.

22. red algae found in the oceans use chlorophyll a, but have red pigment
sushi wraps, thickening agents (ice cream)