XVI International Botanical Congess

Rhodolith beds are widely distributed in the Gulf of California, covering on the order of at least 100 sq km in the southwestern Gulf alone at depths of 3-30m. The highly polymorphic Lithophyllum margaritae is most abundant, occurring with Neogoniolithon sp. and Lithothamnion sp. depending on depth and location. Some individuals are over 100 yrs old. The beds harbor over 300 species of associated invertebrates and algae, and bioturbation by the former is important to bed maintenance at depths below 4.5m. Pleistocene deposits of rhodoliths and associated hard-bodied animals are also common in the Gulf, and comparisons between these and living beds may provide insights into the effects of global warming on this important nearshore community.