Multicellular Protists (algae)• Primary producers• “ Plant-like” seaweeds

– Lack true leaves, stems & roots

– May be filamentous, grow in mats or crusts, sheets, or kelp

• Phaeophyta (browns)• Rhodophyta (reds)• Chlorophyta (greens)

Phaeophyta

• Brown/yellow pigment– Fucxanthin (& chl)

• Diverse morphologies– Simple to large &

complex• Upto 100m

• Fast growing kelp– 1 to 2 feet a day– Important source of algin

• Thickener, stabilizer, emulsifier in many products

Rhodophyta• Red pigments

– Phycobilins

• As a group, expands to greater depths than other algae– Why?

• Coralline algae– CaCO3 in cell walls

• Defense and structure

– Encrusting• Important component of coral

reef environments

• Source of carrageenan & agar (emulsifiers & gel thickeners)

• Nori from Porphyra

Chorophyta

• Green pigments– Chl a & Chl b– Same as plants

• Diverse morphologies– Filamentous– Sheets– Spongy– Calcareous

• Important component of coral reef environments

Kingdom Plantae• Photoautotrophs• Mostly terrestrial, few have

adapted to marine environments– Seagrasses

• Eelgrass (subtidal), surf grass (rocky intertidal; surf zone)

• Provides home and protection to many spp.

– Cordgrasses• Tolerant land plants• Salt marsh habitats

– Mangroves• Tolerant tropical trees & shrubs• Provides habitat & protection for

many tropical estuarine & intertidal spp.