Coral reefs worldwide are under pressure, with coral cover decreasing and cover of macroalgae increasing on many reefs. Once macroalgae has established, it can be extremely difficult to remove, and the reasons for this stability have largely not been determined. One macroalga common on degraded and inshore coral reefs is Sargassum, which can form dense canopies, inhibiting the settlement and growth of corals. In this thesis, I examine the stability of Sargassum-dominated reefs to disturbance events, investigating the relative roles of the holdfasts (‘roots’) vs. propagules (juveniles) to the maintenance of Sargassum biomass, and determine the contribution of herbivores to the removal of these components. Overall, the results of my thesis demonstrate the remarkable capacity of Sargassum to recover after disturbance and provide an insight into why Sargassum is common and increasing on so many reefs worldwide.
Biography: (around 150 words)
Zoe is originally from Victoria. In search of sunnier skies and warmer water, she moved to Townsville to study Marine Biology at JCU in 2010. She completed her honours year with Dr. Andrew Hoey and Prof. David Bellwood in 2013, studying the influence of habitat and macroalgal associations on herbivore foraging. After working as a research assistant at MACRO – the Centre for Macroalgal Resources and Biotechnology for a year, she decided to start her PhD in 2015 under the supervision of Dr. Andrew Hoey and Prof. Morgan Pratchett. Her PhD is focussed on the replenishment of Sargassum (seaweed) after disturbance and the susceptibility of Sargassum to herbivory.