Heat stress and bleaching in corals: a bioenergetic model.

Unlabelled: The coral-dinoflagellate endosymbiosis is based on nutrient exchanges that impact holobiont energetics. Of particular concern is the breakdown or dysbiosis of this partnership that is seen in response to elevated temperatures, where loss of symbionts through coral bleaching can lead to starvation and mortality. Here we extend a dynamic bioenergetic model of coral symbioses to explore the mechanisms by which temperature impacts various processes in the symbiosis and to enable simulational analysis of thermal bleaching.

Measuring multi-year changes in the Symbiodiniaceae algae in Caribbean corals on coral-depleted reefs.

Monitoring coral cover can describe the ecology of reef degradation, but rarely can it reveal the proximal mechanisms of change, or achieve its full potential in informing conservation actions. Describing temporal variation in Symbiodiniaceae within corals can help address these limitations, but this is rarely a research priority. Here, we augmented an ecological time series of the coral reefs of St.

Marine heatwaves threaten cryptic coral diversity and erode associations among coevolving partners.

Climate change-amplified marine heatwaves can drive extensive mortality in foundation species. However, a paucity of longitudinal genomic datasets has impeded understanding of how these rapid selection events alter cryptic genetic structure. Heatwave impacts may be exacerbated in species that engage in obligate symbioses, where the genetics of multiple coevolving taxa may be affected.

Hawaiian coral holobionts reveal algal and prokaryotic host specificity, intraspecific variability in bleaching resistance, and common interspecific microbial consortia modulating thermal stress responses.

Historically, Hawai'i had few massive coral bleaching events, until two consecutive heatwaves in 2014-2015. Consequent mortality and thermal stress were observed in Kāne'ohe Bay (O'ahu). The two most dominant local species exhibited a phenotypic dichotomy of either bleaching resistance or susceptibility (Montipora capitata and Porites compressa), while the third predominant species (Pocillopora acuta) was broadly susceptible to bleaching.