1. Marine Macroalgae

2. Primary Producers Prokaryotes (photosynthetic & chemosynthetic)
Domain Bacteria
Domain Archaea
Eukaryotes (photosynthetic)
Kingdom Protista
Unicellular algae (diatoms, dinoflagellates, coccolithophorids)
Multicellular algae (green, brown, red)
Kingdom Plantae
Seagrasses
Salt marsh plants
Mangroves

3. Macroalgae Are not plants (are in Kingdom Protista)

4. Macroalgae
Bull kelp,
Washington

5. Macroalgae Three kinds: Chlorophyta (green) Phaeophyta (brown)
Rhodophyta (red)

6. Dead Man’s Fingers (Codium)
Chlorophytes
Long Island
types
← Sea lettuce (Ulva)
Dead Man’s Fingers (Codium)
Gutweed (Enteromorpha)
Mostly freshwater (only 10% species are marine)
Chlorophyll a & b

7. Chlorophytes Bubble green algae

8. Chlorophytes Calcareous green algae: Acetabularia,Penicillus, Halimeda

9. Chlorophytes
Calcareous green algae plates become large part of sediment

10. Phaeophytes Chlorophyll a & c, fucoxanthin (yellow-brown pigment)
Almost all species are marine
Most live in temperate to cold water
Rockweed (Fucus)
Knotted wrack (Ascophyllum)

11. Phaeophytes Gulfweed (Sargassum) and Sargasso Sea

12. Phaeophytes Gulfweed (Sargassum) inhabitants

13. Kelp Communities Blades up to North Atlantic kelps:
40 ft long in deeper water
Found in lower intertidal and subtidal zones

14. Kelp Communities

15. Kelp Communities US West Coast and elsewhere –
giant kelp (Macrocystis)
gas sacs – pneumatocysts

16. Kelp Communities Stipes to up to 100 m length (330 ft)
Grow fast, up to 50 cm/day (=20 in/day)
Blades, stipes form canopy when reach the surface – blocks light below

17. Kelp Communities

18. Kelp Communities

19. Kelp Communities When otter populations decline, urchins increase
Urchins overgraze, cut through holdfasts, stipes
Kelp sent adrift, strand on beach
Bottom left barren

20. Rhodophytes More species than green and brown algae combined
Almost all species are marine
More in subtropics and tropics
Chlorophyll a & d, phycobilins (red pigment)
Irish moss
(Chondrus)
(Gracilaria)

21. Rhodophytes
Shallow to deep (200m)
75m (225 ft)
100m (300 ft)
NOAA

22. Rhodophytes Coralline/calcareous (CaCO3) – erect and encrusting forms
NOAA

23. Rhodophytes Coralline/calcareous (CaCO3) – Goniolithon shoals

24. Important Algae Food – raw, cooked, dry
Laver (Porphyra) – nori in sushi
Dulse (Palmaria) - dried
Wakame – seaweed salad, miso soup

25. Important Algae Commercial uses - stabilize, emulsify, thicken
Algin, alginate from giant kelp
Carrageenan from Irish moss
Agar from various red algae