Eight coral species in a 2.5-year mesocosm test show adaptive or dysbiotic symbiont shifts
In a 2.5-year future-ocean experiment, some corals shifted symbionts adaptively under heat, while others diverged stochastically, consistent with dysbiosis.
In a 2.5-year factorial future-ocean mesocosm experiment, researchers tracked symbiont community shifts in eight coral species representing the major coral lineages, according to a study in Science Advances science.org
Science Advancesscience.orgOpen source ↗. They compared replicate fragments taken from the same individual coral. The authors note that coral reefs support over a quarter of marine species and nearly a billion people worldwide.
Responses differed between corals. Some showed stochastic divergence of symbiont communities, consistent with dysbiosis, while others showed deterministic, thermally adaptive shifts. Heat stress generally reduced symbiont diversity and promoted predictable restructuring of the community.
The authors report that the results support deterministic processes under moderate stress and stochastic dysbiosis under extreme conditions. They propose that adaptive and stochastic responses are endpoints along a continuum of host-orchestrated symbiont sorting. The study addresses a long-standing debate over whether coral symbioses will be disrupted or respond adaptively under future ocean conditions, and links coral reef ecology with broader host–microbiome theory.
