National Geographic presents “Super Reefs,” a documentary that explores the remarkable recovery of coral reefs around the Southern Line Islands. The episode, airing on April 22, 2024, showcases the resilience of these ecosystems and their ability to bounce back from the devastating effects of the 2015-2016 El Niño.
The Southern Line Islands, an uninhabited archipelago in the central Pacific belonging to Kiribati, are home to some of the world’s most pristine coral reefs. In 2009, ocean explorer Enric Sala and a team of marine biologists discovered a thriving coral jungle untouched by human activity. The reefs teemed with fish, including endangered species such as the Napoleon wrasse.
However, in 2015 and 2016, a strong El Niño event exposed the islands to 15 weeks of warmer-than-usual temperatures, resulting in coral bleaching. When a research team returned in 2017, they found that half of the corals had died, mainly the cauliflower corals in the Pocillopora genus and the stony corals in the Acropora genus.
Despite the damage, Sala noticed that the corals were covered by crustose coralline algae, which provide an ideal substrate for coral larvae to settle and grow. Additionally, the abundance of herbivorous fish, such as parrotfish and surgeonfish, helped keep the coral free of harmful brown algae.
In 2022, Sala and his team returned to the Southern Line Islands and witnessed a spectacular recovery. The reefs had largely revived, with the Montipora corals thriving and slowly regenerating the Pocillopora corals. Sala attributed this to the massive release of Montipora larvae, which settled and transformed the seascape.
The remoteness and lack of human impact on the Southern Line Islands’ reefs have been crucial to their resilience and recovery.
Super Reefs airs on National Geographic at 10:00 p.m. on Monday, April 22, 2024.
