Multicellular Primary Producers ~ Seaweeds

Seaweeds – marine Macroalgae Threee types – red, brown, and green algae Most species are benthic Can be fouling communities – live on bulkheads, pilings or artificial surface Distinguished by the type of pigment used for photosynthesis and the composition of the cell wall. Abiotic factors – light, temp., tides, wave action, salinity, nutrients Chromatic adaptation – ability of plants to alter photosynthetic pigments in response to light conditions Perennials – live longer than a year

Seaweeds – marine Macroalgae

Red Algae – phylum Rhodophyta

Red algae Mostly marine Epiphytes – live on other plants Adaptations to predation –Make thallus less edible –Changing growing patters(out instead of up) –Complex life cycles Uses –Agar culture material –Thickening agents in foods and pharmaceuticals –Carrageenan – binding agent in ice cream, pudding and salad dressing –Cosmetics –Sushi, soups and seasonings –Animal feed –fertilizer

Red algae life cycle

Brown algae – phylum Phaeophyta

Brown algae- kelp, sargassum Mostly marine Mostly benthic Microscopic to 100 meters Very defined holdfast, stipe and blade Gas filled bladders Uses –Thickening agents in textiles, dental and cosmetics and food –Human consumption –Cattle feed

- thin, broad blades allow for floating on top of water where they can use light to photosynthesize - anchors allow them to stay in one place and not float off to places where the conditions may not be as advantageous to their survival - waxy blades prevent them from drying up - pigment fucoxanthin well adapted for absorbing wavelengths of light in their environment to maximize efficiency of photosynthesis - reproduction by flagellate spores allow offspring to be anchored in places where the environment is equally advantageous for their survival. Brown algae- Adaptations

Kombu Japanese Kelp dish an edible brown seaweed used, typically in dried form, in Chinese and Japanese cooking Seaweed laid out for making Maki rolls

Green algae – phylum Chlorophyta

Example sea lettuce Very few marine macroalgae Most are fresh water and phytoplankton Adaptations to predation: –Rapid growth and reproduction –Can occupy small crevices predators can’t –Deposits calcium carbonate in cell walls –toxins