To understand 1) if climate-resilient coral communities are connected to less-resilient communities to ensure the spread of resilient genes and, 2) to provide more data on the location and function of climate-resilient reef systems so they can be preserved and protected.

This 16-day expedition was the first-ever comprehensive investigation of the hydrodynamics, chemistry, and ecology of the entire coral reef ecosystem. Working with the Palau International Coral Reef Center (PICRC), our team of eight scientists and support staff accessed a total of 12 reefs and islands within the archipelago, nine of which were previously unstudied. The team deployed temperature loggers, pH, oxygen and light sensors, current meters and acoustic recorders, and collected 146 water samples to characterize the full carbonate system chemistry, salinity and nutrient concentrations from the surface down to 150 m depth. Over 25 research dives, the team collected 88 coral cores and sampled tissue from 280 coral colonies for genetics analysis. Through the collaboration with PICRC, ecological surveys of fish, coral size and abundance, and five plankton tows were conducted. In addition, the abundance of new coral recruits at 3 and 10m depth were tracked across eight study sites. Analysis of these samples is currently under way. The intensity of these efforts is fueled by the urgent questions for which we need answers. Palau, together with multiple nations across Micronesia, is revising their Protected Area Network (PAN) design to incorporate climate-change resilient reef communities. These newly discovered coral communities and associated fauna and flora that exhibit resilience or resistance to the levels of ocean warming and acidification projected for the tropical Pacific by the end of the century are critical to protect. To date, Palau is the only coral reef ecosystem studied that exhibits such resilience. Here, within semi-isolated bays and inlets of the Rock Islands, exists a unique group of corals and other coral reef organisms able to withstand the high temperature and low pH conditions that threaten the future of coral reef systems around the world.