Southern Line Islands

Pristine Seas Expedition

At Sea: May – June 2023

The Place

The story of Pristine Seas itself began in 2008 off the remote and uninhabited coastlines of the Southern Line Islands.

Part of the Republic of Kiribati, these tiny isles are located between 2,400 and 3,300 kilometers south of Hawaii. There, in 2009, National Geographic Explorer Enric Sala and his crew witnessed one of the most pristine and untouched reefs of his career, describing them as “the ocean of centuries ago.” Flourishing with life, these reefs were a living example of the importance of maintaining the last pristine areas in the world’s ocean.

The team returned to the islands in 2021 following a devastating warming event where 50% of the coral population died in a mass-bleaching event in 2015-16. When the team arrived, they were astonished to find a near full recovery of the reefs with bursts of color in fish, sharks, and other wildlife. This second expedition was a case study of the power of ocean ecosystems to recover from this catastrophic warming event to its healthy original state when given space from human interference.

The Mission

In an unrivaled opportunity to investigate the resiliency of the bleached coral reefs to global warming, in May 2023, Pristine Seas returned to the southernmost islands of SLI most impacted by the warming event: Flint, Vostok, and Millennium. In just over two weeks, the team conducted 349 dives, spent 439 hours underwater, assessed the abundance of hundreds of species, and deployed the submarine 15 times. These data provide a rare time series for this pristine coral reef archipelago and reveal encouraging insights: the reefs here have continued to recover from the 2016 El Niño that killed half of the corals in the area, therefore full protection of these reefs is fostering unprecedented coral resilience to strong warming events.

The Result

Following the initial expedition in 2009, Sala presented the team’s findings to the government of Kiribati. He used scientific data, photographs, and video from the expedition to inform policymakers about the island nation’s natural heritage and the need to preserve the archipelago for future generations. At the 2014 Our Ocean conference hosted by the U.S. State Department in Washington, D.C., then-President Anote Tong announced that a 12-nautical-mile area around the Southern Line Islands would be closed to commercial fishing beginning in 2015. In 2018, with the help of Pristine Seas’ scientific and economic reports, the Government of Kiribati decided to turn the SLI fisheries closure into a permanent 8,000 km² marine reserve, thus creating the Southern Line Islands Marine Protected Area (SLIMPA).

The results from all three expeditions emphasize the need to maintain strong protections around the Southern Line Islands: the high capacity for recovery demonstrated by these coral reef ecosystems highlights the importance of marine management that aims to preserve natural ecological resilience.

Photo credits: Manu San Félix, Sam Guilford (map), Manu San Félix