Global warming decreases connectivity among coral populations
Nature Climate Change
Global warming is killing corals; however, the effects of warming on population connectivity, a process fundamental to reef recovery, are largely unexplored. Using a high-resolution (as high as 200 m), empirically calibrated biophysical model of coral larval dispersal for the southern Great Barrier Reef, we show that the increased larval mortality and reduced competency duration under a 2 °C warming alter dispersal patterns, whereas projected changes in large-scale currents have limited effects. Overall, there was on average a 7% decrease in the distance larvae disperse (among-reef interquartile range (IQR), −10% to −4%), an 8% decrease in the number of connections into each reef (IQR, −11% to −3%) and a 20% increase in local retention (IQR, 0% to +49%). Collectively, these shifts imply that 2 °C of warming will reduce inter-reef connectivity, hampering recovery after disturbances and reducing the spread of warm-adapted genes. Such changes make protections more effective locally, but may require reducing spacing between protected areas.
Joana Figueiredo, Christopher J. Thomas, Eric Deleersnijder, Jonathan Lambrechts, Andrew H. Baird, Sean R. Connolly, and Emmanuel Hanert. 2021. Global warming decreases connectivity among coral populations .Nature Climate Change . https://nsuworks.nova.edu/occ_facarticles/1237.