International Seaweed Symposia have been held at three-year intervals for nearly 50 years. In the early days they formed the only international forum for marine phycologists, and although there are now frequent phycological meetings their value has not diminished, both because of the increased commercial importance of seaweeds, and because of the unique mix of disciplines that the meetings attract. Industrialists interact with chemists and biologists with the common aim of understanding seaweeds. The main development during the last few decades has been an increase in the cultivation of...