Dr Ross Hill

Postdoctoral Fellow

Ross has recently completed his PhD on the photochemical impacts of coral bleaching on symbiotic zooxanthellae. The threat of extensive and devastating coral bleaching events are becoming more frequent around the world and this research aimed to identify the physiological mechanisms responsible for the loss of photosynthetic efficiency and ultimately, expulsion of zooxanthellae. Chlorophyll fluorescence and oxygen production measurements were used to probe the site of impact along the photosynthetic chain of events in conjunction with the use of several chemical inhibitors and donors. Furthermore, the fate of expelled zooxanthellae in the environment was assessed to identify whether they have the capacity for long-term survival in the water column and whether viable cells could persist in the environment to act as a source of symbionts during coral recovery following a bleaching event.

On the SIPEX voyage to Antarctica, Ross will be studying the susceptibility of sea ice algae to elevated light conditions. It is predicted that snow cover and ice thickness will decline in response to global warming, thus allowing for greater penetration of light to the algae which reside in the bottom layers of ice. These algae are adapted to survive and photosynthesise in very low light environments. Any change to these conditions is likely to result in photoinhibition of these algae, potentially leading to reduced productivity. These algae are of considerable importance as they constitute the base of the food chain in Antarctica and any changes their health will affect all levels of the food chain. This research aims to identify the extent of long-term photoinhibition and impacts to sensitive proteins integral to photosynthesis, under several light intensities.

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