Long-term preconditioning of the coral Pocillopora acuta does not restore performance in future ocean conditions

作者：Christine Roper, Jennifer M. Donelson, Steven H. Ferguson, Madeleine J. H. van Oppen, Neal E. Cantin · 发表于：Coral Reefs · 年份：2023 · DOI：10.1007/s00338-023-02401-8 · 研究领域：Coral and Marine Ecosystems Studies、Ocean Acidification Effects and Responses、Marine and coastal plant biology

Abstract There is overwhelming evidence that tropical coral reefs are severely impacted by human induced climate change. Assessing the capability of reef-building corals to expand their tolerance limits to survive projected climate trajectories is critical for their protection and management. Acclimation mechanisms such as developmental plasticity may provide one means by which corals could cope with projected ocean warming and acidification. To assess the potential of preconditioning to enhance thermal tolerance in the coral Pocillopora acuta , colonies were kept under three different scenarios from settlement to 17 months old: present day (0.9 °C-weeks (Degree Heating Weeks), + 0.75 °C annual, 400 ppm pCO 2 ) mid-century (2.5 °C-weeks, + 1.5 °C annual, 685 ppm pCO 2 ) and end of century (5 °C-weeks, + 2 °C annual, 900 ppm pCO 2 ) conditions. Colonies from the present-day scenario were subsequently introduced to the mid-century and end of century conditions for six weeks during summer thermal maxima to examine if preconditioned colonies (reared under these elevated conditions) had a higher physiological performance compared to naive individuals. Symbiodiniaceae density and chlorophyll a concentrations were significantly lower in mid-century and end of century preconditioned groups, and declines in symbiont density were observed over the six-week accumulated heat stress in all treatments. Maximum photosynthetic rate was significantly suppressed in mid-century and end of centu...