Coral Bleaching: Responding to Stress Factors

Climate change and symbiotic relationships are important elements of the work in my fellowship position with the John R. Pringle Lab at Stanford for the summer of 2019, where I was able to study the symbiosis between sea anemone, Aiptasia pallida (a model organism key to the study of corals and other cnidarian species), and dinoflagellate algae of the genus Symbiodinium. This symbiotic relationship also found in many reef-building corals is crucial to the survival of coral reef ecosystems. If the symbiotic relationship breaks down, coral bleaching (loss of symbiotic algae) occurs and the diverse ecosystem of the reefs become untenable. Human-induced climate change is a leading cause of coral bleaching around the world. This phenomenon is modeled in the lab through the responses of anemone and algae after exposure to artificial heat stress. However, other human-induced stress factors such as ocean acidification, pollution runoff, changing water salinity from melting ice, and sedimentation of ocean water from industrialized agriculture are causing coral reefs to bleach at an alarming rate

The lesson plan outlined here explores the concepts of climate change, symbiotic relationship and adaptation. To understand the importance of climate change on organisms such as cnidarians, students will expose sea anemones to different stress factors to see how they respond to stress and measure the subsequent bleaching rates through observations. They will analyze their findings to determine the impact of each different stress factor. Students will also extrapolate the observed effects to predict the correlated effect of stressors on the coral reefs in the oceans of the world. Throughout the process, students will be learning key scientific and engineering skills which are crucial to academic learning and career prospects in the 21st-century.