Marine plants have rarely been discussed as a distinct and self-contained group. They have traditionally been treated either as the poor relations of marine animals in courses and texts on Marine Biology, or as examples of particular groups of algae, where the essential ‘marine-ness’ of marine plants tends to disappear amongst the taxonomic and morphological parallels with freshwater algae. This book attempts to liberate marine plants from both of these traps by providing an introduction to recent analytical and experimental studies of plant growth in the sea. The physics and chemistry of the marine environment are examined with specific reference to the requirements of marine plants, and most of the book concentrates on those aspects of physiology which are unique to marine plants, or which help us to understand their ecology. This discussion emphasizes the importance of a good background knowledge of the environment for critical measurements of the most important factors, and the necessity for experimental work on marine plants to be well quantified, and to be conducted in ecologically relevant conditions.
Since over 90% of the species of marine plants are algae, most of the book is devoted to the marine representatives of this group, with examples from all oceans and coasts of the world, but there is no detailed morphological or taxonomic treatment. Phytoplankton and seaweeds are discussed together as far as possible, in spite of the obvious morphological and ecological contrasts between them, in order to obtain an integrated picture of the biology of marine plants in general.