Biological Productivity

1. Biological Productivity GAUTAM SANKA

2. Phaeophyta (Brown Algae) • Largest members of the marine plant community that are attached to the bottom in the littoral and inner sublittoral zones. • Dominant pigment is fucoxanthin • Occurs primarily in temperate and cold water areas • Examples include Ralfsia and Pelagophycus(bull kelp) • Sargasum is a genus of brown algae which may be at the bottom of shore waters or floating freely. • Commonly found in the Sargasso Sea • Fucales, an order in phaeophyta, is found near rocky shores

3. Chlorophyta • Division of green algae that is mostly found in freshwater and not much in the oceans • They are mostly intertidal and grow in shallow waters of bays

4. Rhodophyta (Red Algae) • Red algae are very abundant but rarely found in freshwater • Pigment is phycoerythrin • In warm water, algae tends to be relatively small in comparison to algae in cold water • color of red algae varies on the depth in the intertidal or inner sublittoral zones

5. Spermatophyta (seed-bearing plants) • Two that exist in the marine environment are Zostera (eelgrass) and Phyllospadix (surf grass) • Eelgrass • Grass with true roots and is found primarily in quiet waters of estuaries and bays • Surf Grass • Prefers the high energy environment of an exposed rocky coast • Both of these plants are considered to be important sources of detritus food for the marine animals

6. Pyrrophyta (Dinoflagellate Algae) • Using their flagella, these organisms tend to move into favorable areas for plant productivity • Most don’t have protective covering and if they do, it is made of cellulose. Many are luminescent • Red tides result from conditions where up to 2 million dinoflagellates may be found in one liter of water • Mainly responsible for this red tide phenomenon are the following which create toxins • Gymnodinium toxin kills fish and shellfish. • Contributor to Gulf of Mexico red tides • Gonyaulax toxin is not poisonous to shellfish but will concentrate in their tissue and is poinsonous to humans who eat the shell fish • Contributor of cooler waters of the New England and West Coast Area

7. Chrysophyta (Golden Algae) • Containing pigment carotin and store food in form of leucosin (a carb) • Diatoms are plants that are in a shell, fristule, composed of SiO2 • These silica housings accumulate on the ocean bottom and produce a siliceous sediment, diatomite • The top and bottom are called valves; larger valve is epitheca and the smaller valve is hypotheca • Reproduction is simple cell division except an auxospore is formed to grow into a full sized diatom when the original can’t split anymore

8. Chrysophyta Contn. • Coccolithophores are flagellated organisms covered with small calcareous plates, coccoliths made up of CaCO3 • Are included as nanoplankton • Contribute significantly to calcareous deposits in all of the temperate and warmer oceans