Marine Producers

Phytoplankton

Phyto (plant) planktos (wandering)

Microscopic plants that live in the ocean Over 10,000 species of phytoplankton Foundation of the marine food chain 2/3 of all the photosynthesis that takes place

is in the oceans

Diatoms

Marine producers Are unicellular Enclosed by cell walls made largely of silica Aggregate into chains or star-like groups

Algae

Simple aquatic organisms Eukaryotic Photosynthetic

Photosynthesis vs. Respiration

Photosynthesis– Occurs in chloroplasts– Solar energy captured by chlorophyll– Oxygen by-product

Sunlight + CO2 + H2O ----> O2 + Sugars

Respiration– Occurs in mitochondria– Release of energy from breaking down sugars– Carried out by both autotrophs and heterotrophs

Sugars + O2 ----> CO2 + H2O + chemical energy

http://www.cellsalive.com/cells/plntcell_archive.htm

Macroalgae a.k.a. macrophytes

Popular name- seaweed Multicellular Eukaryotic Lots of variation in structure and appearance Three types of seaweed

– Green algae– Brown algae– Red algae

General Structure

No true leaves, stems, or roots Thallus- Body structure Blades- leaf like structure

– Main photosynthetic regions Pneumatocysts

– Gas filled bladders which help keep blades near sea surface maximizing exposure to sun

Stipe– Stem-like structure which provides support

Holdfast– Root-like structure which attaches thallus to the bottom

Do not penetrate through the sand or mud Do not play a significant role in absorption of water and nutrients

Macroalgae Structure

Chlorophyta- Green algae

Occur in both Freshwater and Marine environments

Bright green in color because chlorophyll is not masked by other pigments

Ulva- Sea lettuce Codium fragile- Dead man’s fingers Over 8,000 species 90% are freshwater / 10% saltwater

Ulva Lactuca Kingdom: ProtistaPhylum: ChlorophytaClass: UlvophyceaeOrder: UlvalesFamily: UlvaceaeGenus: UlvaSpecies: Lactuca

Genus Ulva- Sea Lettuce

Codium fragile- Dead man’s fingers

Kingdom: Protista

Division: ChlorophytaClass: BryopsidophyceaeOrder: CodialesFamily: Codiaceae

Genus: Codium

species: fragile

Phaeophyta- Brown Algae

1500 species Predominantly marine Range in color from olive to dark Common in rocky shores Brown due to yellow-brown pigments

– Fucoxanthin Pigment in brown algae that dominates over chlorophyll

Phaeophyta

Rockweeds and Kelps Kelp forests play an important role in marine

ecology by providing food and shelter for marine organisms

Some species grow very large– Nereocystis- Bull Kelp’s stipe can be up to 30

meters long– Macrocystis- Stipes can be up to 100 meters long

These giant kelp are estimated to grow 50cm per day!!!!

Phaeophyta

Kelp Forest Temperate Rain Forest

Rhodophyta: Red Algae

More species than of other two types– 4,000 species – Only a few fresh water species

Red pigments: phycobilins– These pigments mask chlorophyll

Common in rocky shorelines Coralline Algae

– These species deposit calcium carbonate within their cell walls

– Are actively involved in the formation of coral reefs

Rhodophyta

Reproduction In Algae

Asexual reproduction is common– Vegetative reproduction– Fragments of thallus can grow into new organisms– Some reproduce by spores which disperse to new locations

Sexual reproduction– Production of gametes– Spores and Gametes are produced by meiosis

Economic Importance

Used as a food sources in China, Japan, and Korea Used as fertilizers, and in animal feeds Phycocolloids are used in food processing for their

ability to form viscous suspensions– Algin- a phycocolloid that is used in ice cream, cheese, and

baked goods. Also used in shampoos, paints, and cosmetics

– Carrageenan- used as an emulsifier. Gives body to dairy products and pudding

– Agar- Used to form jellies as a thickening agent. Also used as a medium to grow bacteria and molds.

Marine Flowering Plants

Kingdom Plantae Angiosperms: aka flowering plants Dominant land plants Few species live in marine environments Have true roots, stems, and leaves All have flower as dominant reproductive

organ

Seagrasses

Resemble grasses, but are not grasses at all Pollen for reproduction is carried by water

currents Eelgrass

– 50-60 species– Found in shallow coastal waters– Have ribbon-like leaves– Common in oxygen poor sediments

Turtlegrass

Eelgrass

Salt-Marsh Plants

Cordgrasses– Live on land, but are salt

tolerant– Not completely submerged– Become submerged during

high tidal periods

Mangroves

Trees and shrubs living on tropical shores Land plants that tolerate salt Grow in mud bottom estuaries, and coastal

lagoons Arched roots trap sediment and cause more

land to build up expanding the colony toward the sea

Red Mangrove