Algae
kelp forest
Algae
Kingdom Protista
Eukaryotic with chloroplasts - autotrophic some are
unicellular
Multicellular algae are popularly called seaweeds (not
plants). No leaves, stems, roots, or flowers.
Thallus: the complete body
Blades - leaf like, no veins
Pneumatocysts – air bladder - gas filled bladder-keeps
blade near light. May contain carbon monoxide or
other toxic gas.
Stipe - stem like
Holdfast - looks like root but does not absorb food or
H2O. Well developed in kelp.
3 types of Seaweed:
1. Green algae –
phylum
Chlorophyta about
10% are marine
Coralline green
algae - contains
calcium, helps
build coral reef.
This is dead man’s
fingers green algae
2. Brown algae – Phaeophyta -15,000 species are all
marine
Kelps
food source for many people - sushi, seaweed
Macrocytis - common type found in kelp beds or
forests
Habitat for many organisms
3. Red algae - Phylum Rhodophyta 4,000 species;
mostly marine
Red color, significant human uses.
Some are parasitic and derive all nutrients from the
host.
Encrusting coralline red algae helps build coral reefs.
corallina, a coralline red algae
Uses of Algae
• Eastern cultures commonly use for food
• Western cultures extract polysaccharides
thickening, emulsifying and gel.
Undigestible, adds bulk to digestive system
Carrageenan, algin, agar, alginate
• Some brown kelp, Macrocystis can grow a foot a
day
• Harvested like wheat for human uses.
Kelp harvesting ship based out of San Diego
Powdered kelp
-bakery icings
-cooked/instant pudding
-candies
-fruit juices
-jams and jellies
-salad dressings
-whipped toppings
-milk shakes
-chocolate milk
-cheeses
-cottage cheese
-ice cream
cleaners
agar for microbiology
laxatives
capsules and tablets
lotions and creams
shampoos
toothpaste
pastry filling
adhesives
syrups
explosives
There are some marine plants that contribute to primary production: like these sea
grasses that are true plants.
surf grass
True plants that live on tropical ocean shores
Monera, Protista, and Plantae are all marine producers
with Protista contributing the most.