Contents: Preface. 1. Marine and estuarine environment an overview: i. Zonation of the marine environment. ii. Physical processes of the coastal zone. iii. Composition of seawater and sediment. 2. Phytoplankton of the sea: i. Concept of marine and estuarine phytoplankton. ii. Importance of marine and estuarine phytoplankton. iii. General structure and life history of common phytoplankton. 3. Taxonomy and types of marine phytoplankton: i. Common phytoplankton of the sea. ii. Classification of phytoplankton. iii. Phytoplankton bloom and bloom forming species. 4. Phytoplankton and primary production: 1. Concept of primary production. ii. Factors affecting primary production. iii. Contribution of phytoplankton to primary production. 5. Phytoplankton sampling, preservation and diversity study: i. Sampling. ii. Fixation and staining. iii. Diversity study. 6. Estimation of phytoplankton biomass and role of statistics in analysing phytoplankton community: i. Direct count and chlorophyll method. ii. Remote sensing. iii. Application of statistics and computer programming in analysing phytoplankton community. 7. Phytoplankton and water quality: i. Impact of sewage on phytoplankton. ii. Impact of oil on phytoplankton. iii. Impact of heavy metals on phytoplankton.