Seaweed communities

Seaweeds exist as individuals, but they also live together in communities with other seaweeds and animals – communities that affect and are affected by the environment. In Chapter 1 we reviewed the morphologies, life histories, and developmental processes of seaweeds as species. In this chapter we consider the patterns and processes in marine benthic communities as a starting point for later factor-by-factor dissection of the environment. We open with overviews of three major habitats and the seaweeds in them: rocky intertidal zone, tropical reefs, and kelp forests. We hope that these personal essays by some noted algal ecologists will also give the reader a glimpse of the phycologist at work and a sense of the excitement of physiological ecology. Near the end of the chapter, three more ecologists tell about some less well known habitats: salt marshes, seagrasses, and the Arctic.

Essay: The rocky intertidal zone

Few habitats are so frequently visited by ecologists as the rocky intertidal zone, for it offers intermittent access to a fascinating variety of organisms. It must be unique, however, in that it is invariably examined when most of its inhabitants are out of their element. The number of ecologists who study the shore at high tide when its residents are active and operational could, I suspect, be counted on the arms of a starfish. This is a pity, for it is the shore when underwater that is the shore in action (Fig. 2.1).