1. Populations Unit: Marine Algae
NSF Grant DRL

2. Marine Algae

3. Think … Pair … Share
To which kingdom do you think algae belongs and WHY?
Explain how algae get their energy?
What are some examples of marine algae?

4. Kingdom Protista & Plantae
They lack true leaves, stems, and roots
Most are photosynthetic
Include:
Bacillariophyta (Diatoms)
Dinophyta (Dinoflagellates)
Chlorophyta
Rhodophyta
Phaeophyta

5. Basic Structure of Marine Algae
Pneumatocysts
Thallus

6. Thallus is the complete body and all portions can photosynthesize
Kelp Forest, California

7. Blades are leaf-like portions - increase surface area - no veins
Common Sea Lettuce

8. Macrocystis pyrifera Giant Kelp
Some algae have pneumatocysts, or gas-filled bladders allowing the seaweed to stay at the surface
Cool Fact: some pneumatocysts contain carbon monoxide (CO)
Macrocystis pyrifera Giant Kelp

9. - Some algae have a stem-like structure called a stipe
Giant Kelp

10. - in some seaweeds holdfasts are structures that secure the thallus to the bottom

11. 2 3 1 blades stipe holdfasts
Several sea palms at the Pillar Point Marine Reserve.  Half Moon Bay, San Mateo, California 3
stipe
holdfasts 1
List the name of the part and it’s function 1. 2. 3.

12. Divisions of Algae-classified by pigment
* Glaaucophyta = freshwater *Xanthophyta = almost all freshwater

13. Division Rhodophyta Red algae Multicellular
Important to coral reefs because it helps cement the reef together
Phycoerythrins- red pigment which allows red algae to live deeper in the water
Chelidonura Sea Slug

14. Examples: Irish Moss (left) and Nori (right)
Most abundant and widespread macro-algae with over 4,000 species
Examples: Irish Moss (left) and Nori (right)

15. Division Chlorophyta Multicellular
Green algae and land plants have chlorophyll a&b
Chlorophyll a- absorbs different colors of light and used for photosynthesis
Chlorophyll b- helps to capture light
Cell walls made of cellulose

16. Cladophora sericea-Invasive species on West Maui, Hawai’i
Chlorophyta Examples
only 10% of all 6,000-7,000 species are marine
some species are endophytes, or plants that live within the tissues of other plants
Cladophora sericea-Invasive species on West Maui, Hawai’i
Sea  Lettuce

17. Division Phaeophyta
Brown algae varies from olive-green to dark-brown in color due to yellow pigments
Multicellular
Holdfast- anchors the plants
Blades (like leaves)
Pneumatocyst: gas-filled bladders

18. Phaeophyta Example Kelp is the most complex group of brown algae
Phaeophyta Example
Kelp is the most complex group of brown algae
harvested for food in some parts of the world
can be 100 m long and grow to 50 cm per day
-Why does it need so many pneumatocysts?
form kelp beds or kelp forests in colder waters of the N. and S. Pacific
Diver in Kelp forest at Ship Rock Catalina Island, California
Kelp harvester in California

19. Sargasso Sea
Nuestonic community (organisms that float on top of the water)
Drifting rafts of sargassum (brown algae)
Found in the North Atlantic Ocean (in the gyre)
Question:
What are the biotic and abiotic factors that would affect this area?

20. Cyanobacteria Also known as blue-green algae
Photosynthetic Major producers – produce most of Earth’s oxygen
Unicellular
Prokaryotic cells
No true nucleus
Hyella stella:
lives in Marine Limestone

21. Diatoms
Unicellular, Golden colored, some free-floating others colonial
Most productive phytoplankton
Cell walls made of silica

22. Diatoms Examples
Coccolithophores – often used to study climate change, ocean acidification, & eutrophication
Diatom bloom- sudden increase of diatoms
usually during summer when there is an increase in nutrients

23. *from Greek meaning “flame-colored”
Dinoflagellates
*from Greek meaning “flame-colored”
Unicellular
Use flagella to swim
2nd most productive group of primary producers

24. Noctiluca & Symbodinium
Dinoflagellate Examples
Noctiluca & Symbodinium

25. Dinoflagellate Algal Blooms
Algae Blooms
Toxins: Ciguatera:
causes seafood
poisoning (red snapper,
grouper)
HABs (Harmful Algae
Blooms)
*cause Red Tide
Overabundance of algae
that is harmful to the marine organisms, humans, a environment.

26. Bioluminescence
the production and emission of light by a living organism as the result of a chemical reaction during which chemical energy is converted to light energy.
Found in the dinoflagellates
Ninety percent of deep-sea marine life is estimated to produce bioluminescence in one form or another.

27.  Bioluminescent algae Noctiluca Scintillans at Camp Cooinda on the Gippsland Lakes

28. https://www. youtube. com/watch

29. Importance of Marine Algae
Oxygen production (90%)
Habitat
Food
Marine Organisms
Human
Gelatin (thickening agent)
Toothpaste
Sushi