Roughly one third of the world's coral reefs may not be doomed after all. A new study suggests that despite rising ocean temperatures, a significant portion of coral could survive climate change over the next two decades.
The research focused on reefs in Tanzania, including Latham Island, a remote site in the Indian Ocean. Scientists from the Wildlife Conservation Society and other institutions spent years gathering data there. They wanted to understand which corals were dying and which were holding on.
What the scientists found in Tanzanian waters
The team discovered that not all corals respond to heat stress the same way. Some species, particularly those with more resilient symbiotic algae, were able to withstand warmer water better than others. The study identified specific reefs that acted as refuges, where coral cover remained stable even during bleaching events.
Local fishing communities in Tanzania depend on these reefs for their livelihoods. Healthy reefs mean more fish, which means more food and income. When the corals bleach and die, the fish disappear, and families struggle. That is why the findings matter deeply to people living along the coast.
Why some reefs are tougher than others
The researchers found that depth, water flow, and the presence of certain algae all played a role in reef survival. Deeper reefs, for example, experienced less heat stress than shallow ones. Reefs with strong currents also fared better because moving water helped cool the corals down.
The study did not claim that climate change is harmless. It made clear that two thirds of reefs remain at serious risk. But the existence of resilient pockets offers a concrete target for conservation efforts. Instead of trying to save every reef, governments and local groups can focus on protecting the ones most likely to survive.
A practical path forward for conservation
For Tanzania, this means prioritizing the reefs around Latham Island and similar sites. The country has already designated some marine protected areas, but enforcement remains uneven. The study gives local officials a scientific basis for deciding where to invest limited resources.
The research also opens the door to restoration projects that use heat tolerant coral species. If scientists can identify which corals survive naturally, they can propagate those strains and transplant them to degraded areas. That approach is already being tested in parts of the Caribbean and Southeast Asia.
The study was published in a peer reviewed journal and relied on field data collected over multiple years. It did not predict a happy ending for all reefs, but it did show that the situation is not uniformly hopeless. For the people of Tanzania and for marine biologists worldwide, that distinction matters.
