Corals partnering with heat-tolerant algae may survive warming oceans better, but researchers discovered an unexpected vulnerability. According to a new study published in Science Advances, corals hosting the algal genus Durusdinium—which helps them withstand higher temperatures—experience a trade-off.
Lead researcher Jeric Da-Anoy explained: “When corals are associated with Durusdinium algae, their immune system is not suppressed” but instead exhibits “persistent upregulation of immune responses.”
This heightened immune state helps during short-term heat stress but backfires when corals face secondary challenges like bacterial infections, causing greater tissue damage than corals with less heat-tolerant algae partners.
Senior author Sarah W. Davies noted: “Our work shows that this strategy of inducing heat tolerance isn’t free, and…may make them more vulnerable when they encounter disease or other stressors.”
The findings have implications for reef restoration strategies in warming oceans where corals typically face multiple environmental pressures simultaneously.
Journal: Science Advances
DOI: 10.1126/sciadv.ady0833
Publication Date: 26-Aug-2026
Source: Boston University