The genomics of surviving climate change: Are some corals ready?
Coral bleaching is one of the most visible manifestations of the current effects of climate change on global ecosystems. But in almost every bleaching event, some corals remain unaffected even as nearby conspecifics die. What are the differences between heat sensitive and heat tolerant corals? In American Samoa, we have studied two populations of the table top coral Acropora hyacinthus that live in cooler and warmer back reef pools. Reciprocal transplants, transcriptomes, genome scans, symbiont tracking, cryptic species delineation and monitoring of recovery from the 2015 bleaching give a detailed picture of the differences between these populations. What is the practical value of this information? We have demonstrated this in three ways: 1) by testing corals with different heat tolerance for their ability to provide clones for restoration, 2) by examining high latitude populations for heat tolerant alleles and estimating the ability of these populations to evolve in future climate scenarios, and 3) by beginning a broader search for the kinds of habitats likely to harbor heat tolerant corals.