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Red Sea Research Center Seminar - Dr. Joanne Ellis

Start Date: August 30, 2017
End Date: August 30, 2017

​​TITLE:  Modeling climate change impacts and multiple stressor effects on coral reef ecosystems
DATE: Wednesday, August 30, 2017
TIME: 3:00 - 4:00 p.m.
LOCATION: Auditorium 0215 · between Buildings 2 & 3

Global climate change has profound implications on species distributions and ecosystem functioning. In the coastal zone, ecological responses to climate change may be driven by temperature, salinity, heat flux, wave energy, upwelling events and freshwater inputs, which can also interact with additional stressors such as nutrient enrichment. Distinct gradients in temperature, salinity and nutrients are observed along the latitudinal axis of the Red Sea which experiences globally high sea surface temperatures and salinity regimes. We therefore investigated how coral species and functional groups respond across these environmental gradients using multiple linear regression models integrated in situ, satellite and modeled atmospheric and oceanographic data. Species responded to climate variables (sea surface temperature, salinity, heat flux, evaporation), nutrients (chlorophyll, nitrate, nitrite, silicates) and photosynthetically active radiance. The regression model for each species showed significant interactions between climate and nutrient variables with synergistic or antagonistic interactions being species and stressor specific. At the functional level, hard corals and coralline algae were more susceptible to environmental changes, with synergistic interactions identified between nutrient and climate variables. Macroalgae and soft corals were less susceptible to perturbations and nutrients and temperature promoted their growth up to a threshold. The observed responses and effects have important implications for a better understanding of the impact of climate change on coastal ecosystems.

Joanne's research interests include ecosystem services frameworks, marine spatial planning, disturbance and recovery dynamics in coastal ecosystems, biodiversity prioritization to inform ecosystem management, statistical modeling including the identification of multiple stressor interaction effects and climate change impacts on coastal ecology. Her primary research focuses on ecosystem services frameworks, which account for the direct and indirect contributions of ecosystems to human wellbeing.  However her research has also focused on the recovery of coastal communities from disturbance and potential interaction effects of multiple stressors. Joanne has approached these specific research areas using a combination of models and field studies to predict community resilience to disturbance and multiple stressors. This knowledge provides the required biophysical science to quantify stressor ’footprints’, determine ecological responses of ecosystems to multiple stressors and identify ‘tipping points’ that transform ecosystems into non-desirable states.