B. Coral bleaching and symbiotic dysfunction.
This is the second major program within my laboratory. This is the flipside of symbiosis and occurs when the symbiosis between algae and their invertebrate hosts breaks down. Normally, corals and their zooxanthellae live in a harmonious symbiosis in which the photosynthetic symbiont donates 95% of its primary production to the host in return for spoace and nutrients within the cells of the host. In the last 20 years, there has been a massive increase in the incidence of a phenomenon referred to as coral bleaching. Coral bleaching occurs when the symbiosis between reef-building corals and their brown zooxanthellae breaks down and corals rapdily lose pigments and/or symbiotic algae (zooxanthellae). The broad scale of these events and the fact that they are triggered by episodes of warmer than normal water has generated international concern over the potential link to greenhouse warming trends (e.g. Glynn 1991, Hoegh-Guldberg and Salvat 1995, Jones et al. 1997). Major gaps exist in our understanding of the physiology of bleaching and why only some reef-
