3. Seaweed and Plants
Primary Producers: Organisms that produce organic
matter from CO2 usually by photosynthesis
4. Seaweed and Plants
Most seaweeds,
although some are
parasitic to other
seaweeds
Transform solar energy
into chemical energy in
the form of organic
matter
Produce oxygen for
organisms both on land
and in the ocean
6. Multicellular Algae
Seaweed: large,
multicellular algae
Most familiar type of
marine algae
Some biologists prefer
the name
macrophytes or
macroalgae
All multicellular and
eukaryotic
7. Multicellular Algae
Takes structure, types of pigments and stored food
products into consideration
Lack highly specialized structures and reproductive
mechanisms like terrestrial plants
Vary in shapes and sizes
9. Multicellular Algae
Blades: The leaf-like, flattened portions of the thallus of
seaweeds
have a large surface area
main photosynthetic region
not true leaves, no veins
the upper and lower surfaces of blades are identical to each
other
10. Multicellular Algae
Pneumatocysts: Gas-filled bladders that sometimes
keep the blades close to the sea surface
maximizing the exposure of blades to the sunlight
gases include carbon monoxide
11. Multicellular Algae
Stipe: stem-like support structure of seaweeds from
which the blade originates
long and tough in large kelps
12. Multicellular Algae
Holdfast: root-like structure in seaweeds
attaches the thallus to the bottom
not involved in significant water or nutrient
absorption
do not penetrate through sand or mud like roots do
water and nutrients are picked up directly across the
surface
13. Multicellular Algae
the stipe and holdfast usually lack tissues
specialized for water and nutrient transport
15. Types of Seaweed
Three types: green, brown and red
not always easy to recognize visually because of
pigment proportions
primarily limited to areas of shallow water and rocky
shores
16. Green Algae
Chlorophyta
most live in
freshwater and
terrestrial
environments
the group from which
embryophytes (higher
plants) emerged
only 10% are marine
17. Green Algae
most have a simple thallus
pigments and food
reserves are the same as
terrestrial plants
chlorophyll is not usually
masked
thallus is usually a bright
green color
may be branched or
unbranched
21. Brown Algae
Phaeophyta
color varies from olive green to dark brown
due to yellow-brown pigments over chlorophyll
particularly fucoxanthin
22. Brown Algae
almost all 1,500 species are marine
almost always the dominant primary producers on
temperate and polar rocky coasts
23. Brown Algae
include largest and
most complex
seaweeds
belong to the group
Heterokontophyta, a
eukaryotic group
distinguished by
chloroplasts
surrounded by four
membranes
play an important role
in food supplies and
environment
development
24. Kelps
most common and
complex of all brown
algae
about 30 different
species
most found below the
low tide level in
temperate and sub-polar
latitudes
provide food and shelter
for many other
organisms
25. Kelps
Some kelps
consist of a single large blade
ex laminaria
harvested for food in several parts of the world
several blades may grow from a single holdfast
in some species blade is split or branched
in some species the blade can be up to 25m long
(82 ft)
some deep ocean species have a stipe up to
30m high (almost 100ft)
26. Kelps
macrocystis
largest kelp
enormous holdfast
several stipes
elongated blades
at base of each blade is
a pneumatocyst
can grow up to 50cm
per day under optimal
conditions
27. Kelps Forests
Kelp bed/forest: many individual kelps with fast-growing
and intertwining stipes
colder waters of the North and South Pacific
harvested by chopping off the tops for the extraction of
several natural products
among the richest, most productive environments in the
marine realm
30. Red Algae
Rhodophyta
more species of red than green and brown
combined
have red pigments called phycobillins
mask chlorophyll
most species are actually red
31. Red Algae
very few of the 4,000
species live in
freshwater or soil
inhabit most shallow-
water marine
environments
harvested for food and
for the extraction of
various products
32. Red Algae
most filamentous,
many branches with
intricate patterns
increases light-
gathering surface for the
seaweed
dense clumps are
more common
some have lost almost
all traces of
chlorophyll
became parasitic
33. Coralline Red Algae
red algae that deposit calcium carbonate within their
cell walls
important to several marine environments
creates smooth or rough encrusting growths on
rocks
actively involved in the formation and development
of coral reefs
36. Nori
Japanese name for various edible seaweed species
of red algae
The term nori also commonly used to refer to food
products created from these “sea vegetables”
37. Nori
finished products are made by a shredding and rack-
drying process that resembles paper-making
Japan, Korea and China are the current major
producers valued up to $2 billion per year
40. Seaweed Reproduction
some produce spores
typically one-celled, reproductive unit capable of giving
rise to a new individual without sexual fusion
41. Sexual Reproduction
4 basic types of life
histories:
diploid sporophyte
alternation of generation
of three generations
animal-like reproduction
haploid thallus
42. Sexual Reproduction
Factors affecting the number or quality of
spores/gametes
amount of nutrients in the water
temperature of the surrounding environment
day length/amount of light received
45. Economic Importance
phycocolloids: gelatinous chemicals produced by
seaweeds that are used in food production and
product manufacturing
form viscous suspensions or gels (even at low
concentrations)
46. Algin
stabilizer and emulsifier
keeps smooth
used in: ice cream, shampoos, dairy topping,
cosmetics
major source is giant kelp
harvested in California
47. Carageenan
obtained from red algae like Irish moss
valued as an emulsifier
used in: dairy products, puddings,
48. Agar
jelly like substance
used to protect canned meats, in low calorie
foods, laxatives, cosmetics
used as a medium in research
especially for DNA analysis
obtained from red algae
50. Angiosperms
have true roots, stems and leaves
specialized tissues
only seagrasses are truly marine
51. Angiosperms - Seagrasses
adapted to marine life
horizontal stems called rhizomes
pollen carried by currents
Eelgrass is the most commonly distributed
52. Angiosperms – Salt-Marsh Plants
Cordgrasses - true members of the grass family
not true marine plants, tolerant of salt
live in salt marshes and other soft-bottom
environments
offer protection against erosion and provide natural
water purification
Halophytes - salt tolerant plants
ex. pickle weed
53. Angiosperms - Mangroves
Trees and shrubs adapted to live along tropical and
subtropical shores around the world
land plants that can tolerate salt
form lush forests in places like Florida
can survive in both fresh and salt water
environments