Marine environment:  Exposed coasts, estuaries, oceans. Abiotic factors - Geological  factors- oceans, ocean floor, classification of coasts. Physical factors- light, temperature, water movements (waves, tides, currents), Chemical factors-sea water, salinity, O2 & CO2 in sea water, ionic concentration & nutrients.  Biotic factors –Food webs & chains, succession in marine communities, biological interactions.                                                                                 [12]

Zonation of marine algae:  Intertidal, submerged,  sublittoral   zonation  pattern, seasonality.