Abstract:

Anthropogenic disturbances are altering community composition across biomes, disrupting the function and stability of ecosystems, and threatening the provision of ecological goods and services. On coral reefs, climate change and local stressors are reducing populations of habitat-building corals, resulting in unprecedented coral loss and marked shifts in coral species dominance due to differential susceptibilities of coral taxa to disturbance. However, the extent to which shifts in coral species composition will alter the distribution of associated organisms and undermine the resilience of coral reefs remains unclear. This research exploited a natural experiment on reefs surrounding Lizard Island, Australia, where multiple taxonomically distinct coral habitats existed, characterised by dominance of differing coral taxa, to assess the influence of coral species composition on the structure, function and resilience of reef fish assemblages. Specifically, I addressed the following questions: (1) How does coral species composition affect the cross-scale structural complexity of coral reef habitats? (2) How does the functional diversity of reef fish assemblages vary among taxonomically distinct coral habitats? (3) To what extent does pre-disturbance coral species composition influence the susceptibility of reef fish assemblages to coral bleaching events?, and (4) Do critical herbivory functions (browsing and grazing) vary among distinct coral habitats? I highlight the potential ecological consequences of shifts in species configurations, and provide support for assigning greater concern for the composition of habitat-building corals in conservation efforts to promote ecosystem resilience.

Biography:

Laura has carried out her PhD at the ARC Centre of Excellence for Coral Reef Studies, based at James Cook University, with Andrew Hoey, Nick Graham (Lancaster University), and Morgan Pratchett. Her research looked at the role of coral community composition in mediating coral reef ecosystem structure and function. Specifically, she focussed on coral assemblages characterised by dominance of stress-tolerant or weedy coral species to investigate how coral reef dynamics may shift into the future as reefs are reconfigured under current stressors. Laura is from the UK, has a joint BA Hons in Social Anthropology with Development Studies (University of Sussex), an MSc in Marine Environmental Protection (Bangor University), and prior to starting her PhD spent 3.5 years working on marine spatial planning initiatives in the Cayman Islands with the Cayman Islands Department of Environment, The Nature Conservancy, and Bangor University.