1. Lesson 9.3: Algae VS Plants
*Refer to Chapter 5 in your Textbook

2. Learning Goals: I can differentiate between algae and marine plants.
I can label & describe the structure of both algae and marine plants.
I can explain the ecological role of both algae and marine plants .

3. Algae Classification:
Macroalgae = “Seaweed”
Kingdom Protista
3 Phylums:
Chlorophyta = green algae
Rhodophyta = red algae
Phaephyta = brown algae

5. Algae Structure: No roots, stems, or leaves Thallus: entire body
Blade: “leaves” photosynthesize
Stipe: “stem” but does not transport nutrients
Holdfast: “roots” but does not absorb
nutrients
Float: filled with air/gas

6. Algae Ecosystems:
Green algae is the least common in the ocean, but it is found on rocky shore & lagoon ecosystems
Red algae is the only algae that can create a hard outer skeleton to contribute to coral reef ecosystems
Brown algae is the most common in the ocean, and the only algae large enough to create an entire kelp forest ecosystem

7. Algae Uses:
Green algae is mostly used for food, cosmetic, & medicinal purposes
They are also trying to turn green algae into a biofuel
Red algae is also used as food in sushi & as a thickening agent in food like ice cream
Brown algae can be used in herbal supplements as well as extracting iodine

8. Marine Plant Classification:
Kingdom Plantae
Phylum Anthophyta = flowering plants (seagrass & mangroves)
3 Types of Mangroves =
Red
Black
White
LOTS of types of Seagrass
Seagrass is considered to be the only “truly marine plant”
Hydrophyte: lives submerged beneath the water

9. Paddle Grass
Turtle Grass
Widgeon Grass
Shoal Grass
Manatee Grass

10. Red Mangroves: defining feature prop/drop roots above ground
White Mangroves: defining feature is a white flower that blooms within the leaves
Black Mangroves: defining feature pneumatophores which are roots that stick out of the ground like fingers
Red Mangroves: defining feature prop/drop roots above ground

11. Marine Plant Structure:
Structurally more complex than algae:
Leaf: where photosynthesis occurs & gas is released
Stem: transports water & nutrients through plant
Roots: absorb water & nutrients, anchor plant
Seed: contains a dormant embryonic plant
Fruit: layers of tissue protecting the seed
Vascular Tissues:
Phloem: carries nutrients from roots to other parts of the plant
Xylem: carries water, provides structural support

12. Structure

13. Marine Plant Ecosystems:
Seagrass beds provide habitat for many microbes and small organisms like stingrays, crabs, seastars, shrimp in a variety of habitats such as the lagoon and seafloor
Mangroves provide entire ecosystems to both land animals that live in the tree branches, and marine animals that live under roots.

14. Marine Plant Uses:
Both seagrass and mangrove leaves are food for herbivores
Seagrass reduces turbidity (cloudiness) because the roots stabilize the ocean floor preventing currents and waves from stirring up sediments
Mangroves protect coastlines from storm erosion and create nurseries for baby animals
Plant Human Uses:
Wood for hunting tools, contruction
Creating furniture, rooftops, footwear, fishing line, etc
Herbal medicinal recipes
Etc.

15. Marine Plant Uses: Both seagrass & mangroves can be
used for building & extracting dyes
& nutrients

16. Algae & Plant Zonation:
Deepest, to shallow, to land =
Algae, Seagrass, Red, Black, & White Mangroves