Abstract: The issue of multiple stressors and whether their combined effects are more than the sum of their parts (synergism) is one of the most pressing issues in ecology and ecosystem management. Coral reefs have been the ecosystem of choice for much of the research regarding multiple stressors, and hence I have approached the problem from three different perspectives. First, I performed a qualitative and quantitative meta-analysis of the peer-reviewed literature to assess the actual state of knowledge regarding multiple stressors and to identify key research gaps. Second, using the AIMS LTMP survey data, I examined a case study of the interaction between bleaching and disease. Finally, I used an expert elicitation approach to assess how much agreement (or disagreement) existed between coral reef ecologists as to the probability of persistence of coral reefs on the Great Barrier Reef (GBR) given the combined effects of multiple stressors. I then used these expert opinions in a Bayesian Belief Network (BBN) framework in combination with Geographic Information Systems (GIS) to explore spatial heterogeneity in reef persistence probability for selected reefs in the GBR. All three approaches highlighted that considerable uncertainty still exists regarding the prevalence of synergistic effects, and that the evidence for these effects may be as sensitive to the method of analysis as to the experimental context. Furthermore, the future of the GBR appears tenuous given the status quo of stressor levels.

Biography: Originally from California, Stephen grew up on the west coast of Canada before moving east to complete his B.Sc. in Marine Biology and Biotechnology at McGill University in Montreal (where he learned that all you need for lab biology is a microwave and a fridge). He then returned to Vancouver to obtain a Technical Diploma in Geographic Information Systems, which led to a Master’s degree in Zoology at the University of British Columbia (where he learned that all you need for field biology is poop, a Ziploc bag, and a spatula) and a three-year stint as a Wildlife Biologist with a private consulting company (where he learned that all you need for mercenary biology is a firearm and a helicopter).