The original rationale behind this series of workshops was that progress in seaweed aquaculture and marine natural products chemistry would require that we better understand the taxonomy of commercially interesting species. Though this remains our primary goal, we have also come to appreciate that one of the most serious consequences of habitat destruction around the globe is loss of species diversity, including that of marine algae. Biodiversity has been defined as the collection of species (or distinct genetic entities), communities, and ecosystems occurring a geographically defined region. But describing changes in diversity over time, whether resulting from human activities or natural processes, require historical information based on rigorous species identification.