Mechanisms of reef coral resistance to future climate change

TLDR

Reef corals are highly sensitive to heat, yet populations resistant to climate change have recently been identified. The study aimed to determine the mechanisms of temperature tolerance in reef corals. The authors performed reciprocal transplantation of corals between reef sites with distinct temperature regimes and measured physiological and gene expression profiles. Local acclimatization and fixed adaptive effects contributed equally to heat tolerance, with acclimatization achieving the same tolerance within two years as would be expected from long‑term natural selection, demonstrating both short‑term acclimatory and long‑term adaptive acquisition of climate resistance, and indicating that adding these adaptive abilities to ecosystem models could slow predictions of reef demise.

Abstract

Reef corals are highly sensitive to heat, yet populations resistant to climate change have recently been identified. To determine the mechanisms of temperature tolerance, we reciprocally transplanted corals between reef sites experiencing distinct temperature regimes and tested subsequent physiological and gene expression profiles. Local acclimatization and fixed effects, such as adaptation, contributed about equally to heat tolerance and are reflected in patterns of gene expression. In less than 2 years, acclimatization achieves the same heat tolerance that we would expect from strong natural selection over many generations for these long-lived organisms. Our results show both short-term acclimatory and longer-term adaptive acquisition of climate resistance. Adding these adaptive abilities to ecosystem models is likely to slow predictions of demise for coral reef ecosystems.