1. Seaweed and Plants:
Multicellular
Primary Producers

2. Types of Algae Classes Chlorophyta = Green Phaeophyta = Brown
Rhodophyta = Red

3. Seaweeds Seaweeds are another class of primary producers.
Technically they are not weeds, but algae, and still eukaryotic.
Most biologists agree that macrophyte is a much better name.
Some also call them macroalgae.

4. Seaweeds: Green algae Have the same pigments
as land plants (chlorophyll)
More than 7,000 species
Seaweeds are “macro” algae
Alteration of generations

5. Filamentus algae such as Ulva forms paper thin sheets.
“Dead man’s fingers,” Codium fragile and several spp. of Culerpa are known for their tube-like structures.
Padina (brown algae) with flat, calcified blades... advantage?

6. Phaeophyta Largest (size) and most complex of the algae
Nearly all are marine (~1500 spp.)
Brown color comes from accessory pigments (fucoxanthin)

7. Fucus sprialis a common brown algae can be found on
rocky shores. Unlike other algae in this category, its thallus lacks gas bladders.
Knotted rockweed, Ascophyllum nodosum, is common to N. America and Europe.

8. Kelps!
Kelps are the largest seaweed we encounter in the ocean. They are also the most complex.
Due to this large size, many of the kelps are harvested for food!
Who knows where we will find seaweed next?

9. A giant kelp typically grows very slowly because much of its huge thallus is in deep dark waters.
True
False

10. It’s also eaten on a regular basis as “sea noodles.”
Sea palm (Postelsia palmaeformis) contains internal support structures that help them withstand wave action!
It’s also eaten on a regular basis as “sea noodles.”

11. Macrocystis pyrifera, the largest of the kelps anchors itself to the sea floor by use of a massive holdfast. Here we can see not only the large blades, but the extensive pneumatocysts, which are used for buoyancy. Remember: Pneumatocysts developed as a means to maximize energy production through photosynthesis by keeping the seaweed close to the surface.

12. Thalus

13. The holdfasts of seaweeds are analogous to roots because both provide an anchor and absorb nutrients to supply the entire algal body or thallus.
True
False

14. In some seaweeds, leaf-like portions called blades are kept near the sea surface with gas-filled bladders called pneumatocysts.
True
False

15. The Chlorophyta includes the largest algae, the giant kelps.
True
False

16. These kelp obtain huge proportions growing as much as 0.5m/day!
These are when large kelp group together  a kelp forest is develops.
Kelp forests are great for sheltering all sorts of marine life, including Garibaldi, scallops, seals and sharks.
They also provide an opportunity for selective harvesting of the upper sections of the blades for food.

17. Members of the species Rhodophyta red algae, are more numerous than the green and brown algae combined (if we include aquatics).
Although many red algae are in fact
red; due to the presence of red
pigments known as phycobilins,
which mask chlorophyll, these algae
may display an even greater intensity
when exposed to sunlight!
Nearly 4,000 marine species exist and
many are used for food or other specialty
products.
Porphya, a “red” algae

18. Corallina, a coralline algae, deposits CaCO3 within its cell walls which provides structural support and often encrusting many surrounding surfaces.

19. Sexual Reproduction, or not…
Sexual reproduction is expensive both energetically and physiologically.
Sometimes it’s better to reproduce by asexual means from fragments, spores, or buds.
Sometimes algae use both sexual and asexual reproduction depending on environmental conditions.

21. A seaweed with a large sporophyte and a tiny, barely visible gametophyte could be which of these?
sea lettuce
common red alga
giant kelp
any brown alga

22. In many seaweeds, the thallus seen most often is a
sporophyte
gametophyte
zoospore
carposporophyte

23. In flowering plants, the sperm consists of motile zoospores.
a well-developed free-living gametophyte forms.
marine and nearshore species do not have roots.
leaves are present.

24. Products from Seaweed:
Phycocolloids—form gels and increase viscosity of liquids
Algin—stabilizer in ice cream (Macrocystis)
Carageenan—emulsifier (Irish Moss, Chondrus)
Agar—jellies (and of course all your plates in microbiology,
Gelidium, Pterocladiella)

25. Seagrasses (lillies) reproduce through rhizomes, or horizontal stems which grow beneath the sediment.

26. Sea grasses grow in clusters interconnected with horizontal root-like stems.
True
False

27. Seagrasses are considered to belong to the Kingdom Plantae because they
carry on photosynthesis.
can attach to sand.
have chlorophyll.
have specialized tissues that transport nutrients and food.

28. These vascular tissues include
Xylem and rhizoids
Pnematocyst and xylem
Xylem and phloem
Xylem and phycoclloid

29. Sea grasses, being angiosperms, reproduce with flowers that attract insects.
True
False

30. In salt marsh, cordgrasses grow well below the water level.
pickle weed and other halophytes live at higher levels.
mangroves are the dominant plants.
seeds germinate while on the parent.

31. Mangroves

32. Mangroves
Mangroves thrive in salty environments and are able to obtain freshwater from saltwater.
Some spp. secrete excess salt through their leaves while other block absorption of salt at their roots.

33. Salt marsh plants such as cordgrass are fully marine species.
True
False

34. In some mangrove plants, seeds germinate before detaching from the parent tree.
True
False

35. Mangrove Forest

36. Mangrove Impacts
At one time, nearly 0.5 million acres of mangroves surrounded Florida’s coastal zone contributing to the ecosystem’s health in a variety of ways:
Trap and cycle organics, chemical elements, sediment and minerals.
Provide shelter for marine organisms.

37. Plate 9. Black Mangrove, Avecennia germinans.

38. Red Mangrove

39. Plate 10. White Mangrove, Laguncularia racemosa.

41. The northern limit of mangroves is set by which feature of the environment?
salinity of the water
frost
light levels
oxygen levels in the sediment

42. Rhizomes of seagrasses
carry on photosynthesis.
stick upright out of soft, muddy sediments.
cannot transport water or nutrients.
generally grow beneath the sediment.

43. Like calcareous green algae, coralline red algae
can be involved in the development of coral reefs.
live only in the tropics.
always have thalli with segments.
turn pink when dead.

44. Algin is used by people in which way?
to wrap Japanese food
as a medium to grow bacteria
as a stabilizer and emulsifier in the dairy industry
directly as food

45. Going from the surface to the point of attachment to a rock, which is the correct order in which the parts of a giant kelp occur?
holdfast, stipe, pneumatocyst, blade
stipe, holdfast, blade, pneumatocyst
blade, pneumatocyst, stipe, holdfast
pneumatocyst, stipe, blade, holdfast

46. Among red algae, dense clumps are characteristic of species living where?
in deep water
in areas rarely exposed to air
on upper levels of rocky coasts
as parasites on other algae

47. Green algae generally can be found in all of these habitats except
fresh water.
polluted areas.
estuaries.
rocks exposed to heavy wave action.

48. Which thallus shape is not found among kelp?
thin filaments formed by a single cell
a long stipe with one pneumatocyst
several stipes and a massive holdfast
a single large blade