1. Chapter 6
Marine Microbes

2. Key Concepts
Microbial life in the sea is extremely diverse, including members of all three domains of life as well as viruses.

3. Marine Viruses Significance: Marine food webs Population biology
Diseases of marine organisms

4. Marine Bacteria General characteristics simple, prokaryotic, few genes
reproduce by binary fission
many shapes and sizes

5. Nutritional Types Cyanobacteria (blue-green bacteria) photosynthetic
found in high dissolved oxygen, and produce free oxygen

6. Nutritional Types Chemosynthetic bacteria
Use energy from chemical reactions
Less efficient than photosynthesis
Found around hydrothermal vents

7. Nutritional Types (Heterotrophic Bacteria)
Decomposers
Marine snow

8. Symbiotic Bacteria
Chemosynthetic bacteria live within tube worms and clams
Some deep-sea or nocturnal animals host helpful bioluminescent bacteria

9. Archaea General characteristics Small Prokaryotic
Extreme environmental conditions

10. Archaea Nutritional Types
Photosynthesizers, chemosynthesizers and heterotrophs
Most are methanogens
Halobacteria thrive at high salinities

11. Archaea Hyperthermophiles Survive at temperatures exceeding 100o C
Potential for biomedical and industrial application

12. Fungi
Decomposers, prey, pathogens and symbionts

13. Fungi
General features
Heterotrohic decomposers

14. Figure 6-14 (a) ARENICOLOUS MARINE FUNGUS.

15. Fungi Salinity is toxic to fungi, devote energy to removing sodium
Most live on wood from land
Some live on grass in salt marshes
Others live on algae, mangroves or sand

16. Maritime Lichens
Lichens: mutualistic associations between a fungus and an alga

17. Diatoms 2 basic diatom shapes:
Radially symmetrical valves (generally planktonic)
Bilaterally symmetrical valves (generally benthic)

18. Pls note: I do not see this figure in text
Pls note: I do not see this figure in text. Has it been preplaced by Figure 6-18 DIATOMS ?

19. Diatoms Diatomaceous sediments Sink and collect on the seafloor
Mined for use as filtering material, a mild abrasive, and for soundproofing and insulation products
Accumulate in siliceous oozes accounting for most of the worlds petroleum reserves

20. Alveolates Dinoflagellates
Globular, unicellular (sometimes colonial) with 2 flagella
Most are planktonic, some are benthic and others parasitic
Can be bioluminescent – Bioluminescent Bay, Puerto Rico

21. Figure 6-25 DINOFLAGELLATES.

22. Alveolates (Dinoflagellates)
Ecological roles of dinoflagellates
Major component of phytoplankton
Some are parasites of copepods (crustaceans)
Zooxanthellae: symbionts of jellyfish, corals and molluscs

23. Alveolates (Dinoflagellates)
Harmful Algal Blooms (HABs)
Photosynthetic dinoflagellates undergo a population explosion
Colors the water red, orange or brown
Dinoflagellates that cause HABs produce toxins
Paralytic shellfish poisoning (PSP) occurs in humans
Toxins cannot be destroyed by cooking
Oxygen content of the water may be reduced to deadly levels as bacteria decompose animals killed by dinoflagellate toxins