Assessing the role of historical temperature regime and algal symbionts on the heat tolerance of coral juveniles

Abstract

The rate of coral reef degradation from climate change is accelerating and, as a consequence, a number of interventions to increase coral resilience and accelerate recovery are under consideration. Acropora spathulata coral colonies that survived mass bleaching in 2016 and 2017 were sourced from a bleaching-impacted and warmer northern reef on the Great Barrier Reef (GBR). These individuals were reproductively crossed with colonies collected from a recently bleached but historically cooler central GBR reef to produce pure and crossbred offspring groups (warm–warm, warm–cool and cool–warm). We tested whether corals from the warmer reef produced more thermally tolerant hybrid and purebred offs..