Tropical reefs in the aftermath of climate change

Abstract As an era of significant environmental and societal transformations, forecasting the future entails considerable uncertainty. This article gives a perspective on calcifying organisms capable of adapting to a warmer and more acidic ocean, which may also contribute to future reef construction. While it is challenging to conceive, we cannot rule out a transformation of reef ecosystems, possibly characterized by increase in octocorals, a greater presence of giant clams, and a greater ecological prominence of coralline algae along with their rhodoliths. In the Caribbean Sea, reefs will possibly no longer be dominated by the extensive Acropora communities that characterized their preindustrial zenith. Instead, there may be a shift towards ecosystems composed of dense octocoral communities and mesophotic assemblages where scleractinian corals with symbionts adapted to low-light environments are more likely to persist. Rehabilitation in shallow waters can take advantage of coralline algae and coastal reef systems close to seagrass and mangrove ecosystems can improve coral health. Although these changes may seem unsatisfactory, essential ecological services could persist, including habitat provision for many species, spaces for human recreation, and, significantly, a notable contribution to global carbonate cycles. It is crucial to highlight that any human effort to prevent biodiversity loss is both praiseworthy and equitable, as the decline in biodiversity due to climate change is a collective obligation of humanity.