Can Rising Atmospheric CO2 Concentrations Prevent the Thermal Bleaching of Corals?
Volume 8, Number 20: 18 May 2005 http://www.co2science.org/scripts/CO2ScienceB2C/BrowseCatalogEnlarged.jsp?sProductCode=v8n20edit In the introduction to their intriguing review of the thermal aspects of coral bleaching, Smith et al. (2005) note that photoinhibition of photosynthesis and photodamage to photosystem II of the zooxanthellae, with the consequent increase in the production of damaging reactive oxygen species (ROS), have been implicated as the cause of thermal bleaching (Brown, 1997; Fitt et al., 2001; Lesser, 2004; Tchernov et al., 2004). At the end of their review, they additionally report that the thermal bleaching of many corals is ultimately the result of the destruction of photosynthetic pigments by ROS, and that the production by the zooxanthellae of one particular ROS, hydrogen peroxide, may be a signal that triggers a response in the host cell to eject the zooxanthellae or shed the host cell from the coral. These facts resonate with other findings we have reviewed on
