Sea surface temperature in coral reef restoration outcomes

Successful restoration of coral reefs depends on the survival of outplanted species. Research shows that outplanting survival is mixed, with outplants often experiencing rapid mortality in response to various stressors. We used published results on outplant monitoring to investigate the role of sea surface temperature in the survival rates of corals. We find that the maximum temperature experienced at an outplanting site is very important in determining outplant survival, with ∼50% mortality occurring if temperatures reach 30.5 °C. Some genera, however, are more tolerant than others. Outplant survival increases when sites experience greater variability in temperature, where outplants are exposed to temperatures both warmer and cooler than the long-term mean. Similar results were found when considering temperature conditions of the site in the year prior to outplanting. Thus, sea surface temperature data can be used as a tool to assess whether a restoration site is appropriate, with sites chosen to increase outplant survival.