MARINE MACROALGAE AND PLANTS

Marine

macrophytes

• Refers to large primary

producers in habitats

substantially affected by salt

water from the sea

• Marine macroalgae

(seaweeds)

• Seagrass

• Mangroves

SEAWEEDS

Also called marine macroalgae

• “Plant-like” organisms

• Photosynthetic, all contain chlorophyll

• Multicellular or coenocytic

• From a few millimeters or centimeters to 30 m–50 m

• ATTACH TO A SUBSTRATE OR OTHER ORGANISMS

• can be found in splash zone down to the subtidal, drifting or floating

• whee light is available for photosynthesis

Thallus

the entire body of a

seaweed

Holdfast

for attachment,

resembles roots

Stipe

stalk of a seaweed

between holdfast and blade;

resembles a stem

Blade

the flattened or

leaf-like portion of the

seaweed

Pneumatocysts

Gas-filled bladders that keep the blades close to

the sea surface – more photosynthesis can take

place here.

Chemical analysis

seaweeds all have chlorophyll and differ in accessory pigments. They are best identified by _____ because their natural color doesn’t always match their name.

Green seaweeds

• Green, chlorophyll

• Most are unicellular or small multicellular

filaments, tubes or sheets

• Some are calcified

• Exhibit diverse morphologies

Ulva lactuca

Ulva intestinalis

Caulerpa racemosa

Caulerpa lentillifera

Halimeda opuntia

Brown Seaweed

• Multicellular

• Colors can vary from olive green to dark brown.

• Yellow-brown pigments (particularly fucoxanthin) which

masks the green chlorophyll.

• Vary in morphology – may be filamentous, branching,

fan-shaped, with long stalks, fleshy or leathery, etc.

• Are often the dominant primary producers on temperate

and polar rocky coasts.

• some are tropical

Padina australis

Padina boryana

Padina antillarum

Sargassum cristaefolium

Sargassum crassifolium

Sargassum polycystum

Red Seaweed

• Multicellular • Very large group of organisms (more species than green and

brown seaweeds).

• Chlorophyll and phycobilins

• Most are soft bodies (fleshy), but some are

calcified (coralline algae)

Eucheuma and

Kappaphycus

- tropical

- mostly farmed

Halymenia durvillei

Gracilaria salicornia

Tricleocarpa fragilis

Marine flowering plants

•Angiosperms

• plants along the shores and shallow

ocean waters evolved from terrestrial ancestors.

• Versus seaweeds that are originally

aquatic

Seagrasses

• True plants

  • Most species have long green, grass-like leaves

  • Photosynthetic

  • Multicellular

rhizomes

Horizontal stems called —- that

grow beneath sediment

INTERNODES

Stems look somewhat like bamboo, with

cylindrical sections called _____

separated by rings (nodes).

Flowers

very small and inconspicuous

(no need to attract insects for

pollination)

lacunae

provide a continuous

system for gas transport through

the plant. Because water carries

much less oxygen than air and

sediment is devoid of oxygen,

the leaves must be a source of

oxygen for the rest of the body.

• Salty and brackish waters

  • Mostly sandy or muddy

  • Tropical to temperate

  • Coastal oceans except polar seas

  • Intertidal to the subtidal

Where can you find seagrass?

Sediment stabilization

and carbon

sequestration

eCOLOGICAL IMPORTANCE OF SEAGRASS

Enhalus acoroides

Halophila ovalis

Syringodium isoetifolium

Mangrooves

• halophytic (salt

loving) trees, shrubs

and other plants

• adapted to life in wet

soils, saline habitats,

and periodic tidal

submergence.

• tropical and subtropical shores

• brackish to saline tidal waves

whaere can you find mangroves?

• salt pores

• salt exclusion

• viviparity

adaptations to salt water

Salt pores

– located

on leaves, root and

branches. Excess

salt absorbed from

soil secreted

Salt exclusion

roots of some

mangroves exclude

salt

Viviparity

seeds

germinate while

attached. Fully

developed seedlings

drop from tree.

• prop roots

• pneumatophores

• lenticels

Some adaptations

to Low Oxygen in

Soil

Prop roots

roots exposed to air

Pneumatophores

• pencil-lke roots sticks up from the substrate

Lenticels

• slits in the bark and roots

• Habitats, nurseries, and

nesting sites.

• Food

• Contribute to higher water

quality.

• Protect shorelines from

erosion

• natural buffers against waves,

tsunami, storm surge

Ecological importance

Food

edible fruits and honey from flowers

of some species.

Medicines-

Treatment of skin disorders and

sores including leprosy. Headaches,

rheumatism, snakebites, boils, ulcers,

diarrhea, and many more conditions are

traditionally treated with mangrove plants.

Hard wood

used for boat building and

cabinet timber.

Avicennia marina

Sonneratia alba

Rhizophora stylosa